U.S. patent application number 15/146710 was filed with the patent office on 2016-10-27 for refrigerant charge management in a heat pump water heater.
The applicant listed for this patent is Nortek Global HVAC,LLC. Invention is credited to Jie Chen, Justin W. Hampton.
Application Number | 20160313033 15/146710 |
Document ID | / |
Family ID | 51420210 |
Filed Date | 2016-10-27 |
United States Patent
Application |
20160313033 |
Kind Code |
A1 |
Chen; Jie ; et al. |
October 27, 2016 |
REFRIGERANT CHARGE MANAGEMENT IN A HEAT PUMP WATER HEATER
Abstract
Heat pumps that heat or cool a space and that also heat water,
refrigerant management systems for such heat pumps, and methods of
managing refrigerant charge. Various embodiments remove idle
refrigerant from a heat exchanger that is not needed for
transferring heat by opening a refrigerant recovery valve and
delivering the idle refrigerant from the heat exchanger to an inlet
port on the compressor. The heat exchanger can be isolated by
closing an electronic expansion valve, actuating a refrigerant
management valve, or both. Refrigerant charge can be controlled by
controlling how much refrigerant is drawn from the heat exchanger,
by letting some refrigerant back into the heat exchanger, or both.
Heat pumps can be operated in different modes of operation, and
various components can be interconnected with refrigerant conduit.
Some embodiments deliver refrigerant gas to the heat exchanger and
drive liquid refrigerant out prior to isolating the heat
exchanger.
Inventors: |
Chen; Jie; (Saint Charles,
MO) ; Hampton; Justin W.; (Bonne Terre, MO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Nortek Global HVAC,LLC |
O'Fallon |
MO |
US |
|
|
Family ID: |
51420210 |
Appl. No.: |
15/146710 |
Filed: |
May 4, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14278982 |
May 15, 2014 |
9383126 |
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15146710 |
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13548091 |
Jul 12, 2012 |
8756943 |
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14278982 |
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61578753 |
Dec 21, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F25B 2313/02741
20130101; F25B 49/02 20130101; F25B 2313/005 20130101; F25B
2313/02731 20130101; F25B 2313/0292 20130101; F24D 19/1072
20130101; F25B 29/003 20130101; F25B 2339/047 20130101; F25B 13/00
20130101; F25B 2600/2507 20130101 |
International
Class: |
F25B 29/00 20060101
F25B029/00; F25B 49/02 20060101 F25B049/02; F24D 19/10 20060101
F24D019/10; F25B 13/00 20060101 F25B013/00 |
Goverment Interests
LICENSE RIGHTS
[0002] This invention was made under CRADA NFE-11-03561 between
Nordyne and UT-Battelle, LLC, operating and management Contractor
for the Oak Ridge National Laboratory for the United States
Department of Energy. The Government has certain rights in this
invention.
Claims
1. A heat pump that heats or cools a space and also heats water,
the heat pump comprising: an outdoor heat exchanger that transfers
heat between refrigerant and outdoor air or a heat source/sink; an
indoor heat exchanger that transfers heat between the refrigerant
and indoor air; a water heat exchanger that transfers heat from the
refrigerant to water; a compressor; an outdoor expansion device; an
indoor expansion device; a refrigerant management valve; a
reversing valve; a first refrigerant conduit connecting the outdoor
heat exchanger to the outdoor expansion device; a second
refrigerant conduit connecting the indoor heat exchanger to the
indoor expansion device; a third refrigerant conduit connecting the
outdoor expansion device to the indoor expansion device; a fourth
refrigerant conduit connecting a discharge port on the compressor
to the water heat exchanger; a fifth refrigerant conduit connecting
the water heat exchanger to the refrigerant management valve; a
sixth refrigerant conduit connecting the refrigerant management
valve to the reversing valve; a seventh refrigerant conduit
connecting the reversing valve to the outdoor heat exchanger; an
eighth refrigerant conduit connecting the reversing valve to the
indoor heat exchanger; a ninth refrigerant conduit connecting the
refrigerant management valve to the third refrigerant conduit; and
a tenth refrigerant conduit connecting the reversing valve to an
inlet port on the compressor.
Description
RELATED PATENT APPLICATIONS
[0001] This patent application is a continuation-in-part (CIP)
patent application of, and claims priority to, U.S. patent
application Ser. No. 13/548,091, filed on Jul. 12, 2012, titled:
Refrigerant Management for Heat Pump Water Heater, which is a
non-provisional patent application of, and claims priority to, U.S.
Provisional Patent Application No. 61/578,753, filed on Dec. 21,
2011, titled Refrigerant Management for Heat Pump Water Heater,
Apparatus and Methods. These patent applications have at least one
inventor in common with the current patent application and the same
assignee. The contents of these priority patent applications are
incorporated herein by reference. Certain terms, however, may be
used differently.
FIELD OF THE INVENTION
[0003] This invention relates to heat pumps that heat and cool a
space and that also heat water, and systems and methods for
managing refrigerant charge in such heat pumps.
BACKGROUND OF THE INVENTION
[0004] A heat pump is a machine or device that transfers thermal
energy from one location, at a lower temperature, to another
location, which is at a higher temperature. Accordingly, heat pumps
move thermal energy in a direction opposite to the direction that
it normally flows. Some types of heat pumps are dedicated to
cooling only, some types are dedicated to heating only, and some
types perform both functions, for instance, depending on whether
heating or cooling is needed at the time. Heat pump HVAC units have
been used for some time to heat and cool spaces that people occupy
such as the interior of buildings. Heat pumps have also been used
for other purposes such as heating water. Heat pumps are typically
more efficient than alternative heat sources, such as electrical
resistance heating, because heat pumps extract heat from another
source, such as the environment, in addition to providing heat
produced from the consumption of electrical power. Further, in some
situations, the heating and the cooling are both put to beneficial
use at the same time, such as heating domestic hot water while
cooling air for air conditioning. As a result, heat pumps often
reduce energy consumption in comparison with other
alternatives.
[0005] Heat pumps have been used that heat and cool an enclosed
space within a building and that also heat domestic hot water. A
problem encountered with such systems, however, is that an
appropriate refrigerant charge for one mode of operation has been
inappropriate (i.e., insufficient refrigerant charge or excessive
refrigerant charge) in another mode of operation. For example,
during conditions under which a particular heat exchanger of the
heat pump is not needed for transferring heat, liquid refrigerant
has accumulated in that heat exchanger reducing the available
charge for the system to an inappropriately low level of charge.
This has occurred, for example, during conditions under which the
outdoor heat exchanger is not needed for transferring heat, while
the water is being heated and the space is being cooled. This has
also occurred, as another example, during conditions under which
the indoor heat exchanger is not needed for transferring heat,
while the water is being heated and heat is being extracted from
the outdoor air. In the past, it was necessary to correct or
compensate for these inappropriate refrigerant charge levels in
different modes of operation with complex and expensive refrigerant
charge management hardware and systems, or else it was necessary to
avoid certain modes of operation such as those modes just
mentioned, or the heat pumps operated substantially less
efficiently during such modes of operation.
[0006] Further, U.S. Pat. No. 4,299,098 (Derosier) describes
controlling refrigerant charge in a heat pump water heater by
venting an inactive heat exchanger to the suction side of the
compressor. The heat pump of Derosier, however, is not able to heat
the space and heat water at the same time, and is not able to heat
water while also rejecting heat to the environment while the space
is being cooled. In addition, the heat pump of Derosier requires
many expensive components, including control valves and check
valves.
[0007] As a result, needs or potential for benefit or improvement
exist for refrigerant charge management methods and systems for
heat pumps that also heat water that are less expensive, that
utilize existing components to a greater extent, that provide for
more modes of operation of the heat pump, that increase the
efficiency of the heat pump, at least during particular modes of
operation, that are less complex, that can be readily manufactured,
that are easy to install, that are reliable, that have a long life,
that are compact, that can withstand extreme environmental
conditions, or a combination thereof, as examples. Further, needs
or potential for benefit or improvement exist for methods of
controlling, manufacturing, and distributing such heat pumps, HVAC
units, buildings, systems, devices, and apparatuses. Other needs or
potential for benefit or improvement may also be described herein
or known in the HVAC, domestic hot water heater, or heat pump
industries, for example. Room for improvement exists over the prior
art in these and other areas that may be apparent to a person of
ordinary skill in the art having studied this document.
[0008] Further background information describing certain aspects of
prior art and problems therein includes U.S. Pat. No. 5,140,827,
issued to Wayne R. Reedy on Aug. 25, 1992. Potential for benefit
exists over the prior art including managing refrigerant charge
with fewer components, less expensively, more reliably, or a
combination thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a block diagram illustrating an example of a heat
pump operating in a cooling mode (i.e., cooling the space) that
also heats water, the heat pump having an improved system to manage
refrigerant charge;
[0010] FIG. 2 is a block diagram illustrating the example of a heat
pump shown in FIG. 1, except operating in a mode in which the space
is neither heated nor cooled;
[0011] FIG. 3 is a flow chart illustrating an example of a method
of managing refrigerant charge in a heat pump that heats and cools
a space and that also heats water;
[0012] FIG. 4 is a flow chart illustrating an example of a method
of heating and cooling a space and for also heating water,
illustrating multiple modes of operation, some of which can involve
particular acts to manage the refrigerant charge;
[0013] FIG. 5 is a block diagram illustrating an example of a heat
pump operating in a cooling mode (i.e., cooling the space) that
also heats water, the heat pump having an improved system to manage
refrigerant charge that includes a refrigerant recovery valve;
and
[0014] FIG. 6 is a block diagram illustrating the example of a heat
pump shown in FIG. 5, except operating in a mode in which the space
is neither heated nor cooled.
[0015] These drawings illustrate, among other things, examples of
certain aspects of particular embodiments of the invention. Other
embodiments may differ. For example, in some embodiments,
components or acts may be omitted, or acts may be performed in a
different order. Various embodiments may include aspects shown in
the drawings, described in the specification, shown or described in
other documents that are incorporated by reference, known in the
art, or a combination thereof, as examples.
SUMMARY OF PARTICULAR EMBODIMENTS OF THE INVENTION
[0016] This invention provides, among other things, heat pumps that
heat and cool a space and that also heat water (e.g., domestic hot
water), systems and methods of managing refrigerant charge in such
heat pumps, and systems and methods for heating and cooling a space
and for heating water. Particular embodiments deliver hot
refrigerant gas to a particular heat exchanger of the heat pump
that is not needed at that time for transferring heat, driving
liquid refrigerant out of that particular heat exchanger, and then
isolate the particular heat exchanger against additional
refrigerant flowing into the particular heat exchanger. The heat
pump is then operated while the particular heat exchanger is
isolated. Various embodiments remove idle refrigerant from a heat
exchanger that is not needed for transferring heat by opening a
refrigerant recovery valve and delivering the idle refrigerant from
the heat exchanger to an inlet port on the compressor.
[0017] In some embodiments, the heat exchanger is isolated by
closing an electronic expansion valve, actuating a refrigerant
management valve, or both. Refrigerant charge can be controlled, in
some embodiments, by controlling how much refrigerant is drawn from
the heat exchanger, by letting some refrigerant back into the heat
exchanger, or both, for example, while the heat pump is being
operated. Certain embodiments include a digital controller
programmed to control the heat pump, which can include specific
programming instructions, or include specific components, such as
one or more expansion devices and one or more refrigerant
management valves, that are used to isolate the particular heat
exchanger. Further, in some embodiments, components are arranged in
a particular manner, for example, with certain refrigerant conduits
connecting different components.
[0018] Various embodiments provide, for example, as an object or
benefit, that they partially or fully address or satisfy one or
more of the needs, potential areas for benefit, or opportunities
for improvement described herein, or known in the art, as examples.
Certain embodiments provide, for instance, heat pumps that also
heat water (e.g., domestic hot water) and refrigerant charge
management methods and systems for heat pumps that also heat water
that are less expensive, that utilize existing components to a
greater extent, that provide for more modes of operation of the
heat pump, that increase the efficiency of the heat pump, at least
during particular modes of operation, that are less complex, that
can be readily manufactured, that are relatively inexpensive, that
tolerate a certain amount of refrigerant leakage through various
valves, that are easy to install, that are reliable, that have a
long life, that are compact, that can withstand extreme
environmental conditions, or a combination thereof, as
examples.
[0019] Specific embodiments of the invention provide various heat
pumps that heat or cool a space and also heat water. In a number of
embodiments, the heat pump includes an outdoor heat exchanger that
transfers heat, for example, between refrigerant and outdoor air or
a heat source/sink, an indoor heat exchanger that transfers heat
between the refrigerant and indoor air, a water heat exchanger that
transfers heat from the refrigerant to water, a compressor, an
outdoor expansion device, an indoor expansion device, a refrigerant
management valve, a reversing valve, and various refrigerant
conduits.
[0020] In some embodiments, these refrigerant conduits include, for
example, a first refrigerant conduit connecting the outdoor heat
exchanger to the outdoor expansion device, a second refrigerant
conduit connecting the indoor heat exchanger to the indoor
expansion device, a third refrigerant conduit connecting the
outdoor expansion device to the indoor expansion device, and a
fourth refrigerant conduit connecting a discharge port on the
compressor to the water heat exchanger. Further, in a number of
embodiments, these refrigerant conduits include a fifth refrigerant
conduit connecting the water heat exchanger to the refrigerant
management valve, a sixth refrigerant conduit connecting the
refrigerant management valve to the reversing valve, a seventh
refrigerant conduit connecting the reversing valve to the outdoor
heat exchanger, an eighth refrigerant conduit connecting the
reversing valve to the indoor heat exchanger, a ninth refrigerant
conduit connecting the refrigerant management valve to the third
refrigerant conduit, and a tenth refrigerant conduit connecting the
reversing valve to an inlet port on the compressor, as
examples.
[0021] Moreover, some embodiments further include a digital
controller that includes programming instructions, for example, to
manage refrigerant charge by controlling the outdoor expansion
device and the indoor expansion device. Further, in some
embodiments, the digital controller includes programming
instructions to manage refrigerant charge during conditions under
which a particular heat exchanger is not needed for transferring
heat, by delivering refrigerant gas to the particular heat
exchanger and driving liquid refrigerant out of the particular heat
exchanger. Still further, in various embodiments, the particular
heat exchanger is either the outdoor heat exchanger or the indoor
heat exchanger. Even further, in a number of embodiments, the
digital controller includes programming instructions to (e.g.,
while the refrigerant gas is in the particular heat exchanger),
isolate the particular heat exchanger against additional
refrigerant flowing into the particular heat exchanger. Further
still, in some embodiments, the digital controller includes
programming instructions to, while the particular heat exchanger is
isolated against additional refrigerant flowing into the particular
heat exchanger, operate the heat pump, including, for example,
running the compressor and heating the water at the water heat
exchanger. Even further still, in some embodiments, the digital
controller further includes programming instructions to isolate the
particular heat exchanger by controlling the refrigerant management
valve, and to isolate the particular heat exchanger by controlling
the outdoor expansion device or the indoor expansion device.
[0022] Further, in some embodiments, the third refrigerant conduit
directly connects the outdoor expansion device to the indoor
expansion device. Even further, in a number of embodiments, the
fourth refrigerant conduit directly connects the discharge port on
the compressor to the water heat exchanger. Still further, in some
embodiments, the sixth refrigerant conduit directly connects the
refrigerant management valve to the reversing valve. Further still,
certain embodiments include all such direct connections.
[0023] In particular embodiments the heat pump further includes a
refrigerant recovery valve, an eleventh refrigerant conduit
connecting the sixth refrigerant conduit to the refrigerant
recovery valve, and a twelfth refrigerant conduit connecting the
refrigerant recovery valve to the tenth refrigerant conduit.
Moreover, in certain embodiments, the heat pump includes a digital
controller that includes programming instructions to manage
refrigerant charge during conditions under which a particular heat
exchanger is not needed for transferring heat, by opening the
refrigerant recovery valve and thereby removing idle refrigerant
from the particular heat exchanger through the eleventh refrigerant
conduit, through the refrigerant recovery valve, and through the
twelfth refrigerant conduit. Further, in various embodiments, the
idle refrigerant is delivered from the particular heat exchanger to
the compressor, and while the refrigerant recovery valve is open,
the heat pump is operated (e.g., by the digital controller, using
the programming instructions), including running the compressor and
heating the water at the water heat exchanger. Further still, In a
number of embodiments, the particular heat exchanger is either the
outdoor heat exchanger or the Indoor heat exchanger. Even further,
in particular embodiments, the outdoor heat exchanger includes a
ground loop.
[0024] Still other specific embodiments provide various heat pumps
that alternately heat and cool a space and also heat water. In a
number of embodiments, such a heat pump includes, for example, an
outdoor heat exchanger that transfers heat between refrigerant and
outdoor air or a heat source/sink, an indoor heat exchanger that
transfers heat between the refrigerant and indoor air, a water heat
exchanger that transfers heat from the refrigerant to water, a
compressor that compresses the refrigerant, the compressor having
an inlet port and a discharge port, various valves, and various
refrigerant conduits. These valves can include, for example, a
refrigerant management valve, a reversing valve that switches the
heat pump between a cooling mode wherein the space is cooled by the
heat pump and a heating mode wherein the space is not cooled by the
heat pump, and a refrigerant recovery valve. Further, the various
conduits can include for instance, a fourth refrigerant conduit
directly connecting the discharge port on the compressor to the
water heat exchanger, a sixth refrigerant conduit connecting the
refrigerant management valve to the reversing valve, a tenth
refrigerant conduit connecting the reversing valve to the inlet
port on the compressor, and a refrigerant recovery conduit
connecting the sixth refrigerant conduit to the tenth refrigerant
conduit. In a number of embodiments, the refrigerant recovery valve
is located in the refrigerant recovery conduit, for example.
[0025] In some such embodiments, the heat pump further includes a
digital controller that includes programming instructions to manage
refrigerant charge during conditions under which a particular heat
exchanger is not needed for transferring heat, for example, by
opening the refrigerant recovery valve and thereby removing idle
refrigerant from the particular heat exchanger through the
refrigerant recovery conduit and through the refrigerant recovery
valve. In a number of embodiments, the digital controller further
includes programming instructions to deliver the idle refrigerant
from the particular heat exchanger to the compressor, and while the
refrigerant recovery valve is open, to operate the heat pump,
including running the compressor and heating the water at the water
heat exchanger. Further, in a number of such embodiments, the
particular heat exchanger is either the outdoor heat exchanger or
the indoor heat exchanger, and in certain embodiments, the outdoor
heat exchanger includes a ground loop.
[0026] Additionally, in particular embodiments, the heat pump
further includes an outdoor expansion device, an indoor expansion
device, and at least six of: a first refrigerant conduit connecting
the outdoor heat exchanger to the outdoor expansion device, a
second refrigerant conduit connecting the indoor heat exchanger to
the indoor expansion device, a third refrigerant conduit connecting
the outdoor expansion device to the indoor expansion device, a
fifth refrigerant conduit connecting the water heat exchanger to
the refrigerant management valve, a seventh refrigerant conduit
connecting the reversing valve to the outdoor heat exchanger, an
eighth refrigerant conduit connecting the reversing valve to the
indoor heat exchanger, or a ninth refrigerant conduit connecting
the refrigerant management valve to the third refrigerant
conduit.
[0027] Furthermore, in various embodiments, the refrigerant
management valve is a three-way valve, the reversing valve is a
four-way valve, and the refrigerant recovery valve is a two-way
valve, or a subcombination thereof. In a number of embodiments, in
a first mode of operation, the refrigerant management valve
operates to isolate the outdoor heat exchanger, and in a second
mode of operation, the refrigerant management valve operates to
isolate the indoor heat exchanger. Further, in a number of
embodiments, the refrigerant management valve has a first position
and a second position, and when the refrigerant management valve is
in the first position, the heat pump uses both the outdoor heat
exchanger and the indoor heat exchanger to transfer heat. Still
further, in a number of embodiments, when the refrigerant
management valve is in the second position, the heat pump uses only
one of the outdoor heat exchanger or the indoor heat exchanger to
transfer heat.
[0028] In some embodiments, in a first mode of operation, the
refrigerant recovery valve opens to draw refrigerant from the
outdoor heat exchanger to the inlet port on the compressor, and in
a second mode of operation, the refrigerant recovery valve opens to
draw refrigerant from the indoor heat exchanger to the inlet port
on the compressor. Further, in some embodiments, in a first mode of
operation, the heat pump heats the domestic hot water with the
water heat exchanger while cooling the space with the indoor heat
exchanger, including condensing the refrigerant in the water heat
exchanger and managing refrigerant charge in the heat pump by
removing liquid refrigerant from the outdoor heat exchanger. Even
further, in some embodiments, in a second mode of operation, the
heat pump heats the domestic hot water with the water heat
exchanger while extracting heat from the outdoor air or from the
heat source/sink with the outdoor heat exchanger without heating
the space with the indoor heat exchanger and without cooling the
space with the indoor heat exchanger, including condensing the
refrigerant in the water heat exchanger and managing refrigerant
charge in the heat pump by removing liquid refrigerant from the
indoor heat exchanger.
[0029] Still further, in some embodiments, in a third mode of
operation, the heat pump heats the domestic hot water with the
water heat exchanger while cooling the space with the indoor heat
exchanger and while rejecting heat to the outdoor air or to the
heat source/sink with the outdoor heat exchanger, including
desuperheating the refrigerant in the water heat exchanger and
condensing the refrigerant in the outdoor heat exchanger. Even
further still, in some embodiments, in a fourth mode of operation,
the heat pump heats the domestic hot water with the water heat
exchanger while heating the space with the indoor heat exchanger
and while extracting heat from the outdoor air or from the heat
source/sink with the outdoor heat exchanger, including
desuperheating the refrigerant in the water heat exchanger and
condensing the refrigerant in the indoor heat exchanger. In
addition, various other embodiments of the invention are also
described herein, and other benefits of certain embodiments may be
apparent to a person of ordinary skill in the art.
DETAILED DESCRIPTION OF EXAMPLES OF EMBODIMENTS
[0030] A number of embodiments of the subject matter described
herein include heat pumps that heat and cool a space (e.g., within
a building) and that also heat water (e.g., domestic hot water),
systems and methods of managing refrigerant charge in such heat
pumps, and systems and methods for heating and cooling a space and
for heating water. Certain embodiments allow such heat pumps to be
operated in one or more (e.g., two) modes not otherwise available
without complex and expensive refrigerant management systems,
significant loss in efficiency during certain modes or operation,
or a combination thereof. Particular embodiments deliver hot
refrigerant gas to a particular heat exchanger of the heat pump
that is not needed at the time for transferring heat, drive liquid
refrigerant out of that particular heat exchanger, and then isolate
the particular heat exchanger against additional refrigerant
flowing into the particular heat exchanger. The heat pump is then
operated while the particular heat exchanger is isolated. In some
embodiments, the refrigerant charge can be adjusted during
operation. Further, some embodiments remove idle refrigerant from a
heat exchanger that is not needed for transferring heat by opening
a refrigerant recovery valve and delivering the idle refrigerant
from the heat exchanger to an inlet port on the compressor.
[0031] FIG. 1 illustrates an example of a heat pump, heat pump 100
operating in a cooling mode (i.e., cooling the space). In different
modes of operation, heat pump 100 heats and cools a space (e.g.,
within a building) and also heats water (e.g., domestic hot water).
Heat pump 100 has an improved system to manage refrigerant charge,
which will be described in detail in the following paragraphs. FIG.
2 illustrates heat pump 100 operating in a mode that does not cool
the space. Rather, in the mode of operation of FIG. 2, heat is
extracted from the environment, in particular, from the outdoor air
or from the ground. Heat pump 100 is an example of a heat pump that
heats or cools a space and that also heats water. Other embodiments
may differ. Use of a heat pump (e.g., 100) to heat water can be
more efficient and can reduce energy cost for heating water in
comparison to use of a conventional electric resistance water
heater in combination with a heat pump (used just to heat and cool
the space) of the same efficiency.
[0032] In the embodiment illustrated, heat pump 100 includes
outdoor heat exchanger 170 that transfers heat between refrigerant
and outdoor air, indoor heat exchanger 180 that transfers heat
between the refrigerant and indoor air, and desuperheater or water
heat exchanger 190 that transfers heat from the refrigerant to
water (e.g., domestic hot water). Heat pump 100, in this
embodiment, also includes compressor 160, outdoor expansion device
175, indoor expansion device 185, refrigerant management valve 150,
reversing valve 140, and various refrigerant conduits. These
refrigerant conduits include, in this particular embodiment, for
example, first refrigerant conduit 101 connecting outdoor heat
exchanger 170 to outdoor expansion device 175, second refrigerant
conduit 102 connecting indoor heat exchanger 180 to indoor
expansion device 185, and third refrigerant conduit 103 connecting
outdoor expansion device 175 to indoor expansion device 185.
Moreover, this particular embodiment includes, for instance, fourth
refrigerant conduit 104 connecting discharge port 164 on compressor
160 to water heat exchanger (e.g., domestic hot water heat
exchanger) 190, fifth refrigerant conduit 105 connecting water heat
exchanger 190 to refrigerant management valve 150, and sixth
refrigerant conduit 106 connecting refrigerant management valve 150
to reversing valve 140. Further, this particular embodiment
includes seventh refrigerant conduit 107 connecting reversing valve
140 to outdoor heat exchanger 170, eighth refrigerant conduit 108
connecting reversing valve 140 to indoor heat exchanger 180, ninth
refrigerant conduit 109 connecting refrigerant management valve 150
to third refrigerant conduit 103, and tenth refrigerant conduit 110
connecting reversing valve 140 to inlet port 162 on compressor
160.
[0033] A "refrigerant conduit", as used herein, forms an enclosed
passageway through which refrigerant flows or can flow and can be
or include one or more sections of tubing or pipe, one or more
passageways through one or more other components such as fittings,
valve bodies, accumulators (e.g., 120), or a combination thereof,
as examples. Further, refrigerant conduits described herein as
"connecting" two components provide an enclosed passageway between
the two components through which refrigerant flows or can flow, at
least in one or more modes of operation. Unless explicitly
described otherwise, however, specifically identified refrigerant
conduits described herein, connecting different components, as used
herein, do not include one or more other specifically identified
refrigerant conduits described herein. Moreover, refrigerant
conduits described herein may differ in shape or length from what
is shown on the drawings, which are not drawn to scale. Further,
the terms "directly connects" and "exclusively connects" are
defined further below.
[0034] The embodiment shown has two expansion devices 175 and 185.
In this embodiment, in both modes of operation shown in FIGS. 1 and
2, refrigerant is delivered from refrigerant management valve 150
through refrigerant conduit 109 and is introduced to refrigerant
conduit 103 between the two expansion devices 175 and 185. Other
embodiments of heat pumps can function with just one expansion
device, for example, performing the function of expansion device
175, performing the function of expansion device 185, or performing
both such functions. For embodiments that have just one expansion
device, however, where that one expansion device performs the
functions of both expansion device 175 and expansion device 185,
additional components may be necessary to route the refrigerant in
different modes of operation. In many instances, use of two
expansion devices (e.g., 175 and 185) can be less expensive, less
complicated, or both, than providing additional components to route
the refrigerant in different modes of operation with just one
expansion device. Just one expansion device can be used, however,
in embodiments of heat pumps that cool the space but do not heat
the space (e.g., embodiments where a furnace, such as a gas
furnace, is used to provide heat) or in embodiments that heat the
space but do not cool the space, as examples.
[0035] Further, in different embodiments, heat pump 100 can be a
packaged unit (e.g., for roof top installation) or a split system,
with one component installed within the space (e.g., containing,
among other things, indoor air coil 180 and indoor air blower or
fan 188) while a second enclosed component is installed outdoors
(e.g., containing, among other things, outdoor heat exchanger 170,
outdoor fan 178, compressor 160, reversing valve 140, and
accumulator 120) for example. In some embodiments, the hot water
heater can be packaged with the heat pump, or with one component of
a split heat pump, while in other embodiments, the hot water heater
can be a separate component. Heat pump 100 can be a residential
heat pump, for example, and can be used on a house, for instance.
In other embodiments, however, heat pump 100 can be used to heat or
cool (or both) another building such as a business, as another
example. Some embodiments include the building.
[0036] As used herein, an "outdoor heat exchanger" is not
necessarily located outdoors. In a number of embodiments, however,
the "outdoor heat exchanger" exchanges heat with outdoor air. For
instance, in the embodiment illustrated, outdoor heat exchanger 170
exchanges heat between the refrigerant and outdoor air moved by
outdoor fan 178. But in other embodiments, the "outdoor heat
exchanger" exchanges heat with a heat source/sink (e.g., other than
the outdoor air), which may be located outdoors or indoors, in
different embodiments. As used herein, a "heat source/sink" can act
as a heat source, providing heat to the heat pump, can act as a
heat sink, accepting heat rejected by the heat pump, or both.
Examples of such a "heat source/sink" include the ground (e.g., a
geothermal loop), soil, sand, rock, ground water, or surface water
(e.g., a lake, a pond, a stream, or a river), as examples. In some
embodiments, geothermal energy or heat can be used, or a solar
collector or solar heat storage device can be used, for instance,
as a heat source (e.g., for an outdoor heat exchanger). In still
other embodiments, a compost pile or land fill can be used as a
heat source (e.g., for an outdoor heat exchanger), as further
examples. In some embodiments, an artificial heat source/sink, a
thermal mass, or thermal reservoir can be used, which can include a
phase change material, a tank of water, masonry, or concrete, as
examples. Moreover, in some embodiments, a heat sink can be used
that can be below outdoor ambient air temperature, such as a
cooling tower, a fountain, a swimming pool, or a cooling pond, as
examples. In some embodiments, more than one outdoor heat exchanger
can be used, for example, one that exchanges heat with outdoor air
and another that exchanges heat with a heat source/sink. Further,
in some embodiments, more than one heat source/sink can be used,
for instance, each with an outdoor heat exchanger. In some
embodiments, for example, different heat source/sinks may be at
different temperatures and one heat sink may be used to reject heat
while a separate heat source may be used to obtain heat.
[0037] Water heat exchanger 190 can heat water circulated from a
separate tank or water heater (e.g., electric resistance, gas,
solar, geothermal, heat pump, or a combination thereof), for
example, via water pump 198. In some embodiments, refrigerant
delivered to water heat exchanger 190 from compressor 160 never
exceeds the boiling temperature of the water, and pump 198 can be
turned off when water heating is not needed or is not desired and
boiling of the water in water heat exchanger 190 does not occur.
Further, in some embodiments, pump 198 is a variable-speed pump
(e.g., a pump driven by a variable-speed motor or a pump driven by
a motor that is driven by a variable-speed drive, such as a
variable-frequency drive). In some such embodiments, the speed of
pump 198 can be controlled (e.g., by controller 130, via
programming instructions 135, described in more detail below) to
control how much heat is transferred from the refrigerant to the
water in water heat exchanger 190, for example, if heat from the
refrigerant is also needed to heat the space (e.g., via indoor heat
exchanger 180). In other embodiments, pump 198 is a single speed
pump that is cycled on and off as needed, or is a multi-speed pump,
as other examples.
[0038] In some embodiments, the separate water heater (i.e.,
separate from water heat exchanger 190) can include special
connections, fittings, or attachment points that the water is taken
from or delivered to (or both) for circulation through water heat
exchanger 190. In other embodiments, however, a conventional water
heater can be used and existing connections thereon can be used for
circulating water through water heat exchanger 190. In other
embodiments, water heat exchanger 190 includes a tank (e.g., with a
refrigerant coil inside, for instance, in the bottom) and a
separate tank or water heater can be omitted, at least in some
applications. Such embodiments, however, may lack the flexibility
of being able to turn off pump 198 when water heating is not
desired. In some embodiments, a refrigerant bypass can be used for
this purpose. Furthermore, in still other embodiments, a different
fluid other than the water that is ultimately being heated (e.g.,
other than the domestic hot water) is circulated through "water"
heat exchanger 190. This different fluid can also be circulated
through a coil located in the separate tank or water heater or
through a separate heat exchanger located thereby. In such
embodiments, the different fluid can be antifreeze, for example, or
a mixture of water and glycol, such as ethylene glycol.
[0039] In the embodiment illustrated, refrigerant management valve
150 is a three-way valve. In other embodiments, the refrigerant
management valve can be a two-way valve or multiple two-way valves,
as other examples. In one alternative, for instance, refrigerant
management valve 150 is replaced with a Tee and a first two-way
valve is installed in refrigerant conduit 106 while a second
two-way valve is installed in refrigerant conduit 109. These two
(2) two-way valves are then wired so that one is open when the
other is closed. In the embodiment shown, in the cooling mode of
operation shown in FIG. 1, refrigerant management valve 150 allows
outdoor heat exchanger 170 to be either connected in series with
water heat exchanger 190 and indoor heat exchanger 180, or isolated
(in combination with outdoor expansion device 175) from the
remainder of heat pump 100 with water heat exchanger 190 and indoor
heat exchanger 180 connected in series. Similarly, in the
embodiment shown in the mode of operation shown in FIG. 2,
refrigerant management valve 150 allows indoor heat exchanger 180
to be either connected in series with water heat exchanger 190 and
outdoor heat exchanger 170, or isolated (in combination with indoor
expansion device 185) from the remainder of heat pump 100 with
water heat exchanger 190 and outdoor heat exchanger 170 connected
in series.
[0040] Further, in the embodiment illustrated, outdoor expansion
device 175 and indoor expansion device 185 are expansion valves,
and in particular, are electronic expansion valves or EXV's. In
this particular embodiment, indoor expansion device 185 operates in
the cooling mode shown in FIG. 1 to control the refrigerant
superheat at outlet 184 of indoor heat exchanger 180, for instance,
at accumulator 120 (e.g., at inlet 122 of accumulator 120), or
between outlet 184 and inlet port 162 of compressor 160. Further,
in this particular embodiment, outdoor expansion device 175
operates in the dedicated water heating mode shown in FIG. 2 to
control the refrigerant superheat at outlet 174 of outdoor heat
exchanger 170, for instance, at accumulator 120 (e.g., at inlet 122
of accumulator 120), or between outlet 174 and inlet port 162 of
compressor 160. In a number of embodiments, expansion devices 175
and 185 have an integral check valve therein, arranged in parallel
with the orifice of the expansion device, to allow refrigerant to
exit the corresponding heat exchanger without having to pass
through the orifice of that expansion device.
[0041] In other embodiments, other types of expansion devices may
be used other than electronic expansion valves. Further, in some
embodiments, expansion devices can be used that are not electronic.
Examples include thermal expansion valves, or TXVs. In a number of
embodiments, a separate valve (e.g., automatic, electric, or
electronic) is provided in series with the (e.g., non-electronic)
expansion device, as another example. Further, in some embodiments,
outdoor expansion device 175 is not necessarily located outdoors or
in an outdoor enclosure, indoor expansion device 185 is not
necessarily located indoors (e.g., in an air handler of a split
system), or both. Indoor expansion device 185, however, reduces the
pressure of the refrigerant when, or just before, the refrigerant
enters indoor heat exchanger 180 (e.g., when indoor heat exchanger
180 is being used as an evaporator, for instance, as shown in FIG.
1). Similarly, outdoor expansion device 175 reduces the pressure of
the refrigerant when, or just before, the refrigerant enters
outdoor heat exchanger 170 (e.g., when outdoor heat exchanger 170
is being used as an evaporator, for instance, as shown in FIG.
2).
[0042] In this particular embodiment, heat pump 100 also includes
digital controller 130 that includes, for instance, programming
instructions 135 to perform certain acts or functions. In this
embodiment, digital controller 130 includes a processor, memory,
and various connections to control different components of heat
pump 100, among other things. In a number of embodiments, digital
controller includes a user interface, a display, a keypad, a
keyboard, an input device, connections to various sensors,
connections to external networks or to a master control system, or
a combination thereof, as examples. Digital controller can be wired
to various components of heat pump 100 when heat pump 100 is
installed, for instance, with control wiring, power wiring, or
both. Further, instructions 135 can include software running on
digital controller 130, stored in the memory thereof, or both, for
example. In some embodiments, for example, instructions 135 can
include, for instance, instructions to manage refrigerant charge by
controlling refrigerant management valve 150, instructions to
manage refrigerant charge by controlling outdoor expansion device
175, instructions to manage refrigerant charge by controlling
indoor expansion device 185, instructions to control other control
valves or solenoid valves, or a combination thereof.
[0043] Further, in some embodiments, digital controller 130 can
include, for example, programming instructions (e.g., 135) to
manage refrigerant charge during conditions under which a
particular heat exchanger is not needed for transferring heat, by
delivering refrigerant gas to the particular heat exchanger and
driving liquid refrigerant out of the particular heat exchanger. In
certain embodiments, for example, digital controller 130 may
determine, or may act upon a determination made when controller 130
was programmed, that energy consumption can be reduced, operating
cost can be reduced, or efficiency can be improved, by not using
the particular heat exchanger for transferring heat under the
circumstances existing at that time (e.g., relative demand for
heating or cooling and for hot water). As used herein, this is an
example of the particular heat exchanger not being "needed for
transferring heat". As used herein, in this context, being deemed
to not be beneficial is sufficient to be "not needed".
[0044] In various embodiments, the particular heat exchanger that
is not needed for transferring heat can be either outdoor heat
exchanger 170 or indoor heat exchanger 180, for example, depending
on the mode of operation of heat pump 100. Moreover, in some
embodiments, digital controller 130 can include programming
instructions (e.g., 135) to isolate the particular heat exchanger
against additional refrigerant flowing into the particular heat
exchanger, for instance, while the refrigerant gas is in the
particular heat exchanger. Further, in some embodiments, digital
controller 130 can include programming instructions to operate heat
pump 100, including running compressor 160, heating the water at
water heat exchanger 190, or both, for example, while the
particular heat exchanger is isolated against additional
refrigerant flowing into the particular heat exchanger. Even
further, in particular embodiments, digital controller 130 includes
programming instructions (e.g., 135) to perform at least one of the
following acts: isolate the particular heat exchanger by
controlling refrigerant management valve 150, isolate the
particular heat exchanger by controlling outdoor expansion device
175 or indoor expansion device 185, or both.
[0045] Certain embodiments include various methods, for example, of
managing refrigerant charge in a heat pump (e.g., 100) that heats
or cools a space and also heats water (e.g., domestic hot water).
Such a heat pump can include, for example, an outdoor heat
exchanger (e.g., 170) that transfers heat between refrigerant and
outdoor air or a heat source/sink, as examples, an indoor heat
exchanger (e.g., 180) that transfers heat between the refrigerant
and indoor air, a water heat exchanger (e.g., 190) that transfers
heat from the refrigerant to water, a compressor (e.g., 160), and
at least one expansion device (e.g., 175, 185, or both). In this
context, as used herein, the phrase "that transfers heat" means
during at least one mode of operation (e.g., at least one of modes
one to six or acts 401 to 406 described below) of the heat pump
(e.g., 100), not necessarily while a particular act of a particular
method (e.g., 300 described below) is being performed. Various
embodiments of methods can include, for example, at least certain
acts, which can be performed in the order indicated, one or more
other orders, or any order, in some embodiments, except where a
particular order is required, as examples.
[0046] FIG. 3 illustrates a particular example of a method, method
300. In the example of method 300, the acts include, for example,
during conditions under which a particular heat exchanger of the
heat pump (e.g., 100) is not needed for transferring heat, act 301
of driving liquid refrigerant from the particular heat exchanger.
In a number of embodiments, act 301 can include delivering
refrigerant gas to the particular heat exchanger and driving liquid
refrigerant out of the particular heat exchanger, for example,
through at least one expansion device (e.g., outdoor expansion
device 175 or indoor expansion device 185). In the embodiment shown
in FIGS. 1 and 2, for example, compressor 160 can be run to deliver
refrigerant gas to the particular heat exchanger in act 301.
Refrigerant management valve 150 can be positioned to deliver the
refrigerant through refrigerant conduits 105 and 106 to reversing
valve 140, which can be positioned to deliver the refrigerant gas
to the appropriate "particular" heat exchanger, which depends on
the mode of operation.
[0047] In some embodiments, the fan associated with the particular
heat exchanger (e.g., fan 178 or 188) can be off (e.g., remain off
or be turned off) in act 301, or at least part of act 301, to let
the particular heat exchanger get hot and liquid refrigerant
therein to be pushed out or evaporate. In particular embodiments,
for example, the particular heat exchanger fan is left off if the
suction superheat is above a required low limit. In a number of
embodiments, the temperature and pressure will continue to rise in
act 301, at least while the particular heat exchanger fan is off.
How quickly the temperature and pressure will rise (e.g., in act
301) can depend on the speed of the compressor (e.g., 160), in
various embodiments. In a number of embodiments, compressor (e.g.,
160) discharge temperature, discharge pressure, or both, can be
monitored (e.g., at compressor discharge port 164, within
refrigerant conduit 104, or at water heat exchanger inlet 192, as
examples). In some embodiments, pressure can be monitored further
downstream, for example, at water heat exchanger outlet 194, or at
refrigerant conduit 105, for instance. Such monitoring can be
performed continuously or every 5 seconds, as examples, to make
sure these parameters remain below the discharge temperature limit,
pressure limit, or both, for instance, specified by the compressor
manufacturer.
[0048] In this example, the refrigerant gas displaces and drives
the liquid refrigerant out of the particular heat exchanger. In the
embodiment shown, liquid refrigerant will be driven (e.g., in act
301) to the low pressure side (i.e., through the expansion device
that being used to reduce pressure in the mode of operation taking
place). The liquid refrigerant will first flood the evaporator, in
this embodiment, and then may flood the accumulator (e.g., 120).
The accumulator should be properly sized for this purpose. Liquid
refrigerant flooding back to the compressor (e.g., 160) should
typically be avoided. In a number of embodiments, refrigerant
superheat is continuously monitored, for example, or sampled at
regular intervals, for instance, every 5 seconds, for example, at
outlet 174 or 184 of the heat exchanger that is acting as an
evaporator, at accumulator 120 (e.g., at inlet 122 of accumulator
120), or between outlet 174 or 184 and inlet port 162 of compressor
160. If the refrigerant superheat is above a certain temperature
threshold, (e.g., 5 degrees F.), the evaporator fan (e.g., 178 or
188, depending on which heat exchanger 170 or 180 is acting as the
evaporator) is decelerated or turned off, in particular
embodiments, to allow more liquid to be stored in the evaporator.
If the refrigerant superheat is below a particular temperature
threshold, however, in some embodiments, the evaporator fan (e.g.,
178 or 188, depending on which heat exchanger 170 or 180 is acting
as the evaporator) is accelerated or turned on to prevent liquid
refrigerant from flooding the accumulator.
[0049] Another act in method 300 is act 302, which includes, for
instance, while the refrigerant gas (e.g., delivered in act 301) is
in the particular heat exchanger, isolating the particular heat
exchanger against additional refrigerant flowing into the
particular heat exchanger. As used herein "isolating the particular
heat exchanger against additional refrigerant flowing into the heat
exchanger" means blocking all refrigerant conduits to the heat
exchanger so that refrigerant cannot flow into the heat exchanger
from the rest of the heat pump (e.g., 100), for instance, by
closing or changing one or more valves. In this example, act 302 is
performed after act 301. After the particular heat exchanger is
isolated in act 302, the temperature of the particular heat
exchanger and pressure therein will usually drop. Since the
particular heat exchanger is isolated, however, refrigerant from
other components of heat pump 100 (e.g., other than the particular
heat exchanger) cannot flow into the particular heat exchanger,
which prevents loss of refrigerant charge from heat pump 100
(excluding the particular heat exchanger).
[0050] In a number of embodiments, not all of the liquid
refrigerant is driven out of the particular heat exchanger in act
301. Some liquid can remain, in particular embodiments. In certain
embodiments, the amount of liquid refrigerant that remains in the
particular heat exchanger (e.g., at the end of act 301 or when act
302 is performed) is controlled to provide the proper amount of
refrigerant charge in heat pump 100 excluding the particular heat
exchanger. Such control may be based on pressure, for example,
within the system (i.e., heat pump 100). In some embodiments, other
parameters may be measured as well for this determination (e.g.,
when to end act 301 or initiate act 302), such as temperature at
one or more locations in the system.
[0051] In some embodiments, act 301 of driving liquid refrigerant
out of the particular heat exchanger includes monitoring compressor
discharge temperature, for example. Further, in some embodiments,
act 301 of driving liquid refrigerant out of the particular heat
exchanger includes monitoring compressor discharge pressure, for
instance. Even further, in some embodiments, act 301 of driving
liquid refrigerant out of the particular heat exchanger includes
monitoring duration of the act of driving liquid refrigerant out of
the particular heat exchanger. Some embodiments monitor just one
such parameter, other embodiments monitor two such parameters, and
still other embodiments monitor all three of these parameters.
Certain embodiments monitor other parameters as well. In various
embodiments, act 301 of driving liquid refrigerant out of the
particular heat exchanger is terminated when the compressor
discharge temperature exceeds a predetermined compressor discharge
temperature threshold, the compressor discharge pressure exceeds a
predetermined compressor discharge pressure threshold, or the
duration of the act of driving liquid refrigerant out of the
particular heat exchanger exceeds a predetermined duration, as
examples.
[0052] In particular embodiments, act 301 of driving liquid
refrigerant out of the particular heat exchanger includes
monitoring compressor discharge temperature, compressor discharge
pressure, and duration of the act of driving liquid refrigerant out
of the particular heat exchanger, and act 301 of driving liquid
refrigerant out of the particular heat exchanger is terminated when
the compressor discharge temperature exceeds a predetermined
compressor discharge temperature threshold, the compressor
discharge pressure exceeds a predetermined compressor discharge
pressure threshold, or the duration of the act of driving liquid
refrigerant out of the particular heat exchanger exceeds a
predetermined duration, whichever occurs first. In this context, as
used herein, the term "exceeds" means reaches or exceeds. Further,
as used herein, compressor discharge temperature, compressor
discharge pressure, or both, can be measured, for example, (e.g.,
anywhere) between the compressor discharge and the next heat
exchanger or expansion device that the refrigerant passes through.
For example, in the embodiments of FIGS. 1 and 2, compressor
discharge temperature, compressor discharge pressure, or both, can
be measured, for example, at compressor discharge port 164,
refrigerant conduit 104, or at inlet 192 of water heat exchanger
190, as examples. In other embodiments, on the other hand,
substantially all or all of the liquid refrigerant is driven out of
the particular heat exchanger in act 301. In some embodiments, some
refrigerant can be let back in to the particular heat exchanger,
however, to adjust the refrigerant charge (e.g., in act 304,
described in more detail below).
[0053] In the embodiment illustrated, method 300 also includes, for
example, while the particular heat exchanger is isolated (e.g., as
initiated in act 302) against additional refrigerant flowing into
the particular heat exchanger, act 303 of operating the heat pump
(e.g., 100). Act 303 can include running compressor 160, for
example. In a number of embodiments, act 303 can also include
heating water at heat exchanger 190, as another example. In a
number of embodiments, act 303 begins when act 302 takes place.
[0054] In various embodiments the "particular heat exchanger" can
be the outdoor heat exchanger (e.g., 170), the indoor heat
exchanger (e.g., 180), or the water heat exchanger (e.g., 190). In
the embodiment illustrated in FIGS. 1 and 2, however the
"particular heat exchanger" can only be outdoor heat exchanger 170
or indoor heat exchanger 180 because sufficient valves and
refrigeration conduit are not included in this particular
embodiment to isolate (e.g., in act 302) water heat exchanger 190.
Other embodiments may include such valves and conduit, as another
example, to isolate the water heat exchanger (e.g., in the sixth
mode of operation or act 406, described below). In the particular
embodiment illustrated in FIGS. 1 and 2, the "particular heat
exchanger" can be the outdoor heat exchanger (e.g., 170) or the
indoor heat exchanger (e.g., 180), depending on the mode of
operation. In certain embodiments, in a first mode of operation,
the "particular heat exchanger" is the outdoor heat exchanger
(e.g., 170), in a second mode of operation or the "particular heat
exchanger" is the indoor heat exchanger (e.g., 180). Further, in
some embodiments, the heat pump operates in the first mode of
operation but not the second mode of operation, in some
embodiments, the heat pump operates in the second mode of operation
but not the first mode of operation, and in some embodiments, the
heat pump operates in the first mode of operation under certain
conditions and in the second mode of operation under other
conditions (e.g., as determined by controller 130).
[0055] In certain embodiments, for example (e.g., in the first mode
of operation), the particular heat exchanger is the outdoor heat
exchanger (e.g., 170), and the act of delivering refrigerant gas to
the particular heat exchanger and driving liquid refrigerant out of
the particular heat exchanger (e.g., act 301) includes, for
instance, during conditions under which the outdoor heat exchanger
(e.g., 170) is not needed for transferring heat (e.g., as
determined by digital controller 130 of heat pump 100), delivering
refrigerant gas to the outdoor heat exchanger and driving liquid
refrigerant out of the outdoor heat exchanger. Moreover, in such
embodiments, the act of isolating the particular heat exchanger
against additional refrigerant flowing into the particular heat
exchanger (e.g., act 302) includes, for instance, while the
refrigerant gas is in the outdoor heat exchanger (e.g., 170),
isolating the outdoor heat exchanger against additional refrigerant
flowing into the outdoor heat exchanger (e.g., by actuating
refrigerant management valve 150, by closing expansion device 175,
or both). Further, in a number of such embodiments, the act of
operating the heat pump (e.g., 303), including running the
compressor (e.g., 160) includes, while the outdoor heat exchanger
is isolated (e.g., in act 302) against additional refrigerant
flowing into the outdoor heat exchanger, operating the heat pump
(e.g., 100), including running the compressor (e.g., 160), heating
the water at the water heat exchanger (e.g., 190), and cooling the
space using the indoor heat exchanger (e.g., 180), for example.
[0056] In various embodiments (e.g., in a second mode of
operation), the particular heat exchanger is the indoor heat
exchanger (e.g., 180), and the act of delivering refrigerant gas to
the particular heat exchanger and driving liquid refrigerant out of
the particular heat exchanger (e.g., act 301) includes, for
example, during conditions under which the indoor heat exchanger is
not needed for transferring heat (e.g., as determined by controller
130), delivering refrigerant gas to the indoor heat exchanger
(e.g., 180) and driving liquid refrigerant out of the indoor heat
exchanger. Moreover, in a number of embodiments, the act of
isolating the particular heat exchanger against additional
refrigerant flowing into the particular heat exchanger includes,
for instance, while the refrigerant gas is in the indoor heat
exchanger, isolating the indoor heat exchanger (e.g., 180) against
additional refrigerant flowing into the indoor heat exchanger
(e.g., act 302, for instance, by actuating refrigerant management
valve 150, by closing expansion device 185, or both). Further, in a
number of such embodiments, the act of operating the heat pump
(e.g., 303), including running the compressor (e.g., 160) includes,
while the indoor heat exchanger is isolated against additional
refrigerant flowing into the indoor heat exchanger, operating the
heat pump, including running the compressor (e.g., 160), heating
the water at the water heat exchanger (e.g., 190), and extracting
heat from outdoor air or from a heat source/sink, as examples,
using the outdoor heat exchanger (e.g., 170), for instance.
[0057] In different embodiments, the method can include the first
mode of operation, the second mode of operation, or both, or can
include at least one of the first mode of operation or the second
mode of operation, as another example. In some embodiments, the
method includes just the first mode of operation. In other
embodiments, the method includes just the second mode of operation.
And in still other embodiments, the method includes both the first
mode of operation and the second mode of operation, as another
example.
[0058] In a number of embodiments, act 302 of isolating the
particular heat exchanger against additional refrigerant flowing
into the particular heat exchanger includes closing a particular
expansion device or electronic expansion valve that is connected to
the particular heat exchanger, for instance, with a first
refrigerant conduit. Moreover, in particular embodiments, act 303
of operating the heat pump includes keeping the particular
expansion device or electronic expansion valve closed for at least
a majority of act 303 of operating the heat pump (e.g., 100). In
different embodiments, the "particular electronic expansion device"
can be outdoor expansion device 175 or indoor expansion device 185,
as examples. Moreover, in certain embodiments, in a first mode of
operation, the "particular electronic expansion device" is outdoor
expansion device 175, and in a second mode of operation, the
"particular electronic expansion device" is indoor expansion device
185, as another example.
[0059] Further, in some embodiments or modes of operation in which
the "particular electronic expansion device" is outdoor expansion
device 175, the "first refrigerant conduit" is first refrigerant
conduit 101 connecting outdoor heat exchanger 170 to outdoor
expansion device 175. Further still, in some embodiments or modes
of operation in which the "particular electronic expansion device"
is indoor expansion device 185, the "first refrigerant conduit"
(i.e., in the context of this example) is second refrigerant
conduit 102 connecting indoor heat exchanger 180 to outdoor
expansion device 185. Even further still, in some embodiments, even
in the context of this example, the particular expansion device or
electronic expansion valve can be opened for a short time (e.g., in
act 304) to let refrigerant into the particular heat exchanger to
adjust the refrigerant charge in the system (e.g., in heat pump 100
excluding the particular heat exchanger). In a number of
embodiments, the particular expansion device or electronic
expansion valve can be opened (e.g., in act 304) for a minority or
small fraction (e.g., less than 10, 5, 3, 2, or 1 percent) of the
duration of act 303 of operating the heat pump, as examples. Act
304 can be performed, in particular embodiments, to let refrigerant
into the particular heat exchanger to adjust the refrigerant charge
in the active system (e.g., in heat pump 100 excluding the
particular heat exchanger and certain refrigerant conduits
connected to the particular heat exchanger). In a number of
embodiments, act 304 may be controlled (e.g., by controller 130)
based on pressure, for example, within the system (i.e., within
heat pump 100). In some embodiments, other parameters may be
measured as well for this determination (e.g., to control act 304),
such as temperature at one or more locations in the system. In
other embodiments, on the other hand, refrigerant charge may be
controlled in another way.
[0060] In certain embodiments, act 302 of isolating the particular
heat exchanger against additional refrigerant flowing into the
particular heat exchanger includes actuating a refrigerant
management valve (e.g., 150). In the particular embodiment shown,
refrigerant management valve 150 is located, for example, in a
refrigerant conduit (e.g., 105 and 106, as shown) that connects
water heat exchanger 190 to reversing valve 140 that is used to
switch heat pump 100 between a heating mode, in which the heat pump
heats the space, and a cooling mode, in which the heat pump cools
the space. In the embodiment shown, in either the first mode (FIG.
1) or the second mode (FIG. 2), act 302 is accomplished by
switching refrigerant management valve 150 so that refrigerant
entering refrigerant management valve 150 from refrigerant conduit
105 is directed into refrigerant conduit 109 rather than into
refrigerant conduit 106. When act 302 takes place, or prior to act
302 taking place, the particular expansion device (e.g., 175 or
185, depending on the mode of operation) is closed (e.g., under the
direction of controller 130). The particular fan (e.g., 178 or 188
depending on the mode) can be turned off or remain off, during act
303, and water pump 198 is turned on, in the embodiment
illustrated, In embodiments and modes of operation in which the
water heat exchanger is the particular heat exchanger, however, the
water pump can be off during act 303. Compressor 160 is set to the
desired speed (in embodiments where compressor 160 is a variable
speed compressor or has a variable speed drive) in act 303 (e.g.,
under the control of controller 130), and the evaporator fan (e.g.,
whichever fan 178 or 188 is not the "particular" fan) is turned on
or set to the desired speed (e.g., by controller 130) in the
embodiment illustrated.
[0061] Moreover, in the particular embodiment illustrated, act 302
of isolating the particular heat exchanger against additional
refrigerant flowing into the particular heat exchanger includes
closing the particular expansion device or electronic expansion
valve (e.g., 175 or 185) and actuating the refrigerant management
valve (e.g., 150). In the particular embodiment illustrated, both
the appropriate expansion device and the refrigerant management
valve are actuated to isolate the heat exchanger. Which expansion
device or valve is actuated depends on which heat exchanger (e.g.,
170 or 180) is being isolated (i.e., which heat exchanger is the
"particular heat exchanger") in the particular mode of operation
sought (e.g., the first mode of operation or the second mode of
operation described herein).
[0062] Still referring to FIG. 3, as mentioned, some embodiments
include, for example, act 304 of adjusting the refrigerant charge.
In certain embodiments, as illustrated, act 304 of adjusting the
refrigerant charge takes place after act 302 of isolating the
particular heat exchanger against additional refrigerant flowing
into the particular heat exchanger. In a number of embodiments,
however, act 304 of adjusting the refrigerant charge takes place
during act 303 of operating the heat pump (e.g., 100). In some
embodiments, act 304 of adjusting the refrigerant charge includes
using the particular electronic expansion valve (e.g., expansion
device 175 or 185) to let refrigerant into the particular heat
exchanger. In other embodiments, on the other hand, act 304 of
adjusting the refrigerant charge includes using the refrigerant
management valve (e.g., 150) to let refrigerant into the particular
heat exchanger. Moreover, in particular embodiments, act 304 of
adjusting the refrigerant charge includes using both one of the
particular electronic expansion valves (e.g., expansion device 175
or 185) and the refrigerant management valve (e.g., 150) to let
refrigerant into the particular heat exchanger. In many
embodiments, however, use of one valve is sufficient for act 304.
In various embodiments, act 304 of adjusting the refrigerant charge
includes using at least one of the particular electronic expansion
valve (e.g., expansion device 175 or 185) or the refrigerant
management valve (e.g., 150) to let refrigerant into the particular
heat exchanger. In some embodiments, in act 304, refrigerant
management valve 150 is opened and held open for 0.1, 0.25, 0.5, 1,
2, 3, 4, or 5 seconds, as examples, or within a range from 0.1 to
10 seconds, 0.25 to 5 seconds, 0.5 to 4 seconds, or 1 to 3 seconds,
as examples, before being closed. Further, in some embodiments, in
act 304, electronic expansion valve or expansion device 175 or 185
is opened and held open for 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15,
20, or 30 seconds, as examples, or within a range from 1 to 30
seconds, 2 to 20 seconds, 4 to 15 seconds, or 8 to 12 seconds, as
examples, before being closed. In certain embodiments, in act 304,
electronic expansion valve or expansion device 175 or 185 is opened
to the default condition or the Y-signal is applied, for
example.
[0063] In certain embodiments, act 304 of adjusting the refrigerant
charge includes monitoring refrigerant subcooling at the water heat
exchanger outlet (e.g., 194), for example, and letting refrigerant
into the particular heat exchanger, for instance, if the subcooling
at the water heat exchanger outlet (e.g., 194) exceeds a
predetermined subcooling threshold. In this context, the "water
heat exchanger outlet" means anywhere from the water heat exchanger
(e.g., 190) to the next heat exchanger or expansion device that the
refrigerant passes through after leaving the water heat exchanger
(e.g., indoor expansion device 185 in the mode shown in FIG. 1 or
outdoor expansion device 175 in the mode shown in FIG. 2, whichever
of these two expansion valves is not associated with the heat
exchanger that is acting as the particular heat exchanger). Thus,
in this context of monitoring refrigerant subcooling for act 304,
the "water heat exchanger outlet" includes refrigerant conduits
105, 109, and part of 103 from 109 to indoor expansion device 185,
in the mode shown in FIG. 1, as well as water heat exchanger 190,
refrigerant management valve 150, and inlet 182 of indoor expansion
device 185. (In this example, inlet 182 of indoor expansion device
185 is an inlet in the mode shown in FIG. 1 but is an outlet in the
mode shown in FIG. 2.) Similarly, in this context, the "water heat
exchanger outlet" includes refrigerant conduits 105, 109, and part
of 103 from 109 to outdoor expansion device 175, in the mode shown
in FIG. 2, as well as water heat exchanger 190, refrigerant
management valve 150, and inlet 172 of outdoor expansion device
175. (In this example, inlet 172 of outdoor expansion device 175 is
an inlet in the mode shown in FIG. 2 but is an outlet in the mode
shown in FIG. 1.)
[0064] In some embodiments, the predetermined subcooling threshold
is 15 degrees F., for example. For instance, in some embodiments,
if the subcooling is above 15 degrees F., the refrigerant charge is
adjusted (e.g., in act 304) and if the subcooling is below 15
degrees F., the refrigerant charge is not adjusted (act 304 is not
performed). In other embodiments, on the other hand, the
predetermined subcooling threshold is between 5 and 30 degrees F.,
between 10 and 20 degrees F., between 12 and 18 degrees F., or
between 13 and 17 degrees F., as examples. In particular
embodiments, once act 304 is performed or the refrigerant charge is
adjusted, a minimum stabilization time is allowed to pass before
act 304 is repeated or the refrigerant charge is adjusted again.
This minimum stabilization time can be 60 seconds, for example. In
other embodiments, the stabilization time can be between 20 and 180
seconds, between 30 and 120 seconds, or between 45 and 90 seconds,
as examples. In a number of embodiments, the same criteria is
applied whether the indoor heat exchanger (e.g., 180) or the
outdoor heat exchanger (e.g., 170) is acting as the isolated or
"particular" heat exchanger.
[0065] In some embodiments, act 304 is not initiated until at least
a certain amount of time after act 303 is started (e.g., after act
302). This amount of time may be 1, 2, 3, 4, 5, 7, or 10 minutes,
as examples, or within a range from 1 to 10 minutes, from 2 to 7
minutes, from 2 to 5 minutes, or from 3 to 4 minutes, as examples.
In a number of embodiments, in act 304, if the subcooling is too
high, the particular expansion device (e.g., electronic expansion
valve, for instance, 175 or 185, depending on the mode of
operation) is opened or the refrigerant management valve 150 is
opened (e.g., briefly) to allow some refrigerant to flow back into
the particular heat exchanger. This event can be rather short to
prevent too much refrigerant from flowing back into the particular
heat exchanger, and can last less than a minute, 10, 5, 3, 2, or 1
seconds, less than such a number of seconds, or a fraction of a
second, as examples, after which the particular expansion device or
the refrigerant management valve is closed. Generally, use of an
electronic expansion valve for act 304 provides for a gradual and
controlled change in refrigerant charge and resulting subcooling.
In other embodiments, however, a refrigerant management valve
(e.g., 150) can be used for act 304, for example, in embodiments
that do not have an electronic expansion valve (e.g., in
embodiments that have a TXV). In some embodiments, after a period
of time (e.g., 1, 2, 3, 4, 5, 7, or 10 minutes, as examples) act
304 is repeated if the subcooling is still too high.
[0066] In some embodiments, during conditions under which a certain
heat exchanger of the heat pump (e.g., 100) is used as an
evaporator, act 301 of driving liquid refrigerant out of the
particular heat exchanger includes monitoring refrigerant
superheat, for example, between the evaporator and the compressor
(e.g., 160). In this example, the "evaporator" is one of the heat
exchangers of heat pump 100 other than the "particular heat
exchanger". In some embodiments and modes of operation, for
instance, as shown in FIG. 1, the evaporator is indoor heat
exchanger 180 and the particular heat exchanger is outdoor heat
exchanger 170. Further, in some embodiments and modes of operation,
for example, as shown in FIG. 2, the evaporator is outdoor heat
exchanger 170 and the particular heat exchanger is indoor heat
exchanger 180. Moreover, in this context, "between the evaporator
and the compressor" includes, in the example of FIG. 1, indoor heat
exchanger outlet 184, refrigerant conduit 108, reversing valve 140,
refrigerant conduit 110, accumulator 120, and compressor inlet port
162. Furthermore, in this context, "between the evaporator and the
compressor" includes, in the example of FIG. 2, outdoor heat
exchanger outlet 174, refrigerant conduit 107, reversing valve 140,
refrigerant conduit 110, accumulator 120, and compressor inlet port
162.
[0067] In a number of embodiments, if the refrigerant superheat
between the evaporator and the compressor (e.g., 160) is less than
a predetermined bottom superheat threshold, then the method (e.g.,
300) includes (e.g., within act 301) starting or accelerating an
evaporator fan that blows air through the evaporator. In the
example of FIG. 1, for instance, indoor air fan 188 is the
evaporator fan. In the example of FIG. 2, on the other hand,
outdoor air fan 178 is the evaporator fan. In some embodiments, the
evaporator and evaporator fans (as well as the particular heat
exchanger) are different components in different modes of
operation. Even further, in a number of embodiments, if the
refrigerant superheat between the evaporator and the compressor
(e.g., 160) exceeds a predetermined top superheat threshold, then
the method (e.g., 300) includes (e.g., within act 301) stopping or
decelerating the evaporator fan that blows air through the
evaporator.
[0068] In some embodiments and modes of operation, the evaporator
fan is a single speed fan (i.e., a fan having a single-speed motor
that is either on or off, without a variable-speed drive). In a
number of such embodiments, if the refrigerant superheat between
the evaporator and the compressor is less than the predetermined
bottom superheat threshold, then the evaporator fan that blows air
through the evaporator is started (e.g., from a stop). Further, in
such embodiments and modes of operation, if the refrigerant
superheat between the evaporator and the compressor exceeds the
predetermined top superheat threshold, then the evaporator fan that
blows air through the evaporator is stopped (e.g., is turned off).
Further, in some embodiments and modes of operation, the evaporator
fan is a multiple speed or variable speed fan (i.e., a fan having a
multiple-speed motor or a variable speed drive). In a number of
such embodiments, if the refrigerant superheat between the
evaporator and the compressor is less than the predetermined bottom
superheat threshold, then the evaporator fan that blows air through
the evaporator is accelerated (e.g., increased in speed, either
from a stop or from a lower speed). Further, in such embodiments
and modes of operation, if the refrigerant superheat between the
evaporator and the compressor exceeds the predetermined top
superheat threshold, then the evaporator fan that blows air through
the evaporator is decelerated (e.g., reduced in speed or turned
off).
[0069] Certain embodiments include various methods of heating and
cooling a space and also for heating water, for example, domestic
hot water. Such a method can include, for example, in any order, at
least certain acts, which can be performed in different modes of
operation. FIG. 4 illustrates an example of such a method, method
400, which includes various acts or modes of operation. In certain
acts of FIG. 4, outdoor air is identified. In particular,
embodiments, however, a heat source/sink, other than outdoor air,
such as the ground or ground water, can be used instead of, or in
addition to, outdoor air. In the embodiment illustrated, method 400
includes, in a first mode of operation, act 401 of heating water,
for instance, domestic hot water, while cooling the space without
rejecting heat to outdoor air or to a heat source/sink and without
extracting heat from the outdoor air or from the heat source/sink,
as examples. Heat pump 100 is performing act 401 in FIG. 1, for
example. In this first mode of operation (e.g., act 401 in FIG. 4),
in the embodiment shown in FIG. 1, during act 303 of method 300
shown in FIG. 3, indoor heat exchanger 180 acts as the evaporator
and water heat exchanger 190 acts as the condenser. Thus, heat pump
100 moves thermal energy from the space to the water (e.g.,
domestic hot water), cooling the space while heating the water.
[0070] Further, method 400 also includes, in the embodiment shown,
in a second mode of operation, act 402, of heating water (e.g.,
domestic hot water) while extracting heat from the outdoor air (or
from a heat source/sink), without heating the space and without
cooling the space. Heat pump 100 is performing act 402 in FIG. 2,
for example. In this second mode of operation (e.g., act 402 in
FIG. 4), in the embodiment shown in FIG. 2, during act 303 of
method 300 shown in FIG. 3, outdoor heat exchanger 170 acts as the
evaporator and water heat exchanger 190 acts as the condenser.
Thus, heat pump 100 moves thermal energy from the outdoor air or
from the heat source/sink, as examples, to the water (e.g.,
domestic hot water), cooling the environment, for instance, while
heating the water.
[0071] The first mode of operation, act 401, is a combined cooling
(of the space) and water heating mode, and the second mode of
operation, act 402, is a dedicated water heating mode. Both the
first and the second modes of operation (e.g., acts 401 and 402)
are water heating modes in which all of the heat moved by heat pump
100 in these modes (except for minor losses) is delivered to the
water (e.g., via water heat exchanger 190). These modes of
operation provide for higher capacity water heating than other
possible modes of operation, since in these modes, the water heat
exchanger (e.g., 190) can fully condense the refrigerant to a
subcooled liquid rather than just desuperheating the refrigerant.
This can be a significant advantage, particularly under conditions
when demand for heating of the space is not present and demand for
cooling of the space is not especially high. Since these two modes
of operation do not use one of either the indoor heat exchanger
(e.g., 180) or the outdoor heat exchanger (e.g., 170), changing to
either of these modes of operation (i.e., the first mode or the
second mode of operation) will result in the accumulation of liquid
refrigerant in the unused heat exchanger and insufficient
refrigerant charge in the heat pump (e.g., 100), unless refrigerant
management action is taken such as method 300 shown in FIG. 3 and
described herein, other methods described herein, or other more
elaborate and more costly solutions. Thus, use of method 300, for
example, or other methods described herein, at least in the first
and second modes of operation, provides for greater system
flexibility under different operating conditions.
[0072] Further still, method 400 includes, in the embodiment
illustrated, in a third mode of operation, act 403 of heating water
(e.g., domestic hot water) while cooling the space and while
rejecting heat to the outdoor air or to the heat source/sink, as
examples. In this third mode of operation (e.g., act 403 in FIG.
4), indoor heat exchanger 180 acts as the evaporator and water heat
exchanger 190 acts as a desuperheater. Outdoor heat exchanger 170
acts as the condenser. Thus, heat pump 100 moves thermal energy
from the space to the water (e.g., domestic hot water) and to the
outdoor air, in this embodiment, cooling the space while heating
the water and heating the environment. The third mode of operation,
act 403, is appropriate for circumstances under which demand for
cooling of the space is high or demand for heating of the water is
insufficiently high to use all of the heat removed from the space
to meet the cooling demand. Further, in some embodiments, in one or
more modes of operation, where water heat exchanger 190 acts as a
desuperheater, some condensation of the refrigerant can take place
in water heat exchanger 190. Even further, in some embodiments, in
one or more modes of operation, where a heat exchanger acts as a
condenser, some desuperheating of the refrigerant can take place in
that heat exchanger.
[0073] Moreover, method 400 includes, in this embodiment, in a
fourth mode of operation, act 404 of heating the water while
heating the space and while extracting heat from the outdoor air
(or from a heat source/sink, as another example). In this fourth
mode of operation (e.g., act 404 in FIG. 4), indoor heat exchanger
180 acts as the condenser and water heat exchanger 190 acts as a
desuperheater. Outdoor heat exchanger 170 acts as the evaporator.
Thus, heat pump 100 moves thermal energy from the outdoor air, for
instance, to the space and to the water (e.g., domestic hot water)
and heating the space while heating the water and cooling the
environment. The fourth mode of operation, act 404, is appropriate
for circumstances under which demand exists for both heating of the
space and for heating of the water, but neither demand is so high
as to overshadow the other.
[0074] Even further still, method 400 includes, in the embodiment
shown, in a fifth mode of operation, act 405 of cooling the space
while rejecting heat to the outdoor air (or to a heat source/sink,
as another example), without heating water (e.g., domestic hot
water). In this fifth mode of operation, water pump 198 is turned
off. Further, in this fifth mode of operation (e.g., act 405 in
FIG. 4), indoor heat exchanger 180 acts as the evaporator and
outdoor heat exchanger 170 acts as the condenser. Thus, heat pump
100 moves thermal energy from the space to the outdoor air, cooling
the space while heating the environment. In this mode of operation,
in the embodiment illustrated in FIG. 1. for example, water heat
exchanger 190 acts simply as a refrigerant conduit. In other
embodiments, a refrigerant bypass can route the refrigerant around
the water heat exchanger (e.g., 190), as another example. Such a
refrigerant bypass can include at least one bypass valve (e.g., a
three-way valve or a two-way valve, suitable refrigerant conduit,
and fittings, such as Tee's, for instance. In embodiments where the
water heat exchanger (e.g., 190), can act as the "particular heat
exchanger", there may be two bypass valves (e.g., two three-way
valves), or the bypass valve may be a four-way valve, as other
examples. In some embodiments, such a refrigerant bypass can reduce
refrigerant pressure drop in comparison with routing the
refrigerant through the water heat exchanger (e.g., 190) in act
405. The fifth mode of operation, act 405, is appropriate for
circumstances under which demand exists for cooling of the space
but there is no demand for heating of the water (e.g., the water is
already at a maximum temperature).
[0075] Still further, in a sixth mode of operation, act 406 of
heating the space while extracting heat from the outdoor air (or
from a heat source/sink, as another example), also without heating
water (e.g., domestic hot water). In this sixth mode of operation,
water pump 198 is turned off. Further, in this sixth mode of
operation (e.g., act 406 in FIG. 4), indoor heat exchanger 180 acts
as the condenser and outdoor heat exchanger 170 acts as the
evaporator. Thus, heat pump 100 moves thermal energy from the
outdoor air, for instance, to the space, cooling the environment
while heating the space. In this mode of operation, in the
embodiment illustrated in FIG. 2. for example, water heat exchanger
190 acts simply as a refrigerant conduit. In other embodiments, a
refrigerant bypass can route the refrigerant around the water heat
exchanger (e.g., 190), as another example. Such a refrigerant
bypass can include at least one bypass valve (e.g., a three-way
valve or a two-way valve, suitable refrigerant conduit, and
fittings, such as Tee's, for instance. In embodiments where the
water heat exchanger (e.g., 190), can act as the "particular heat
exchanger", there may be two bypass valves (e.g., two three-way
valves), or the bypass valve may be a four-way valve, as other
examples. In some embodiments, such a refrigerant bypass can reduce
refrigerant pressure drop in comparison with routing the
refrigerant through the water heat exchanger (e.g., 190) in act
406. The sixth mode of operation, act 406, is appropriate for
circumstances under which demand for heating of the space is high
and demand for heating of the water is insufficiently low that it
is desirable to use all of the heat removed from the environment to
heat the space rather than heating the water. This mode is also
appropriate for circumstances under which demand exists for heating
of the space (even if not high) and there is no demand for heating
of the water (e.g., the water is already at a maximum
temperature).
[0076] In various embodiments, it is a significant aspect that all
four of the acts 401, 402, 403, and 404 are accomplished by the
same heat pump. Further, in some embodiments, it is a significant
aspect that all six of the acts 401, 402, 403, 404, 405, and 406
can be and are accomplished by the same heat pump. In a number of
embodiments, these different acts or modes of operation are
accomplished at different times, for example, when different
demands exist for heating, cooling, or both. Further, in various
embodiments, the physical configuration of the heat pump makes
these different acts or modes possible and practical in the same
heat pump. Further, in a number of embodiments, the physical
configuration of the heat pump makes these different acts or modes
cost effective.
[0077] In some embodiments, pump 198 is a variable-speed or
multi-speed pump and pump 198 is operated (e.g., by controller 130
via programming instructions 135) at a lower speed when heat
exchanger 190 is being used (e.g., only) to desuperheat the
refrigerant (e.g., in act 403 or 404), and pump 198 is operated at
a higher speed when heat exchanger 190 is being used to (e.g.,
fully) condense (e.g., in addition to desuperheat, in some
embodiments) the refrigerant (e.g., in act 401 or 402). In various
embodiments, this higher speed (e.g., of act 401, 402, or both) is
1.5, 1.75, 2, 2.25, 2.5, 3, 3.5, 4, or 5 times faster, or within a
range between two of these values, as examples, than the lower
speed (e.g., of act 403, 404, or both). For example, in some
embodiments, pump 198 is operated at a lower speed when heat
exchanger 190 is being used to heat water while the space is also
being heated by the refrigerant (e.g., in act 404).
[0078] When pump 198 is being operated at a lower speed, the water
is heated to a higher temperature, in a number of embodiments, but
due to the much lower flow rate of the water, the total amount of
heat removed from the refrigerant can be much less than when pump
198 is operated at a higher speed. In some embodiments, the speed
of pump 198 is varied over a range of speeds (e.g., in acts 403,
404, or both) depending on the demand or relative demand for hot
water, space conditioning, or both. In certain embodiments,
however, demand or relative demand for hot water is given a
priority over demand for space conditioning, at least when a hot
water temperature is below a minimum temperature threshold.
Further, in a number of embodiments, pump 198 is turned off during
act 405 and 406 (e.g., when the water temperature in the tank
reaches a maximum temperature threshold). When pump 198 is off, the
water in heat exchanger 190 can become even hotter (e.g., than the
maximum temperature threshold), in a number of embodiments, but
remain below the boiling point of the water. In addition, when pump
198 is off, the water in heat exchanger 190 is not circulated to
the hot water tank, so water in the hot water tank is not heated
(e.g., significantly) and heat is not absorbed by the water other
than an initial (e.g., negligible) amount of heat to heat the water
in heat exchanger 190.
[0079] In a number of embodiments, the HVAC unit controller (e.g.,
130) can select the mode of operation (e.g., from FIG. 4), for
instance, by controlling reversing valve 140, by controlling
refrigerant management valve 150, by controlling water pump 198, by
controlling expansion devices 175 and 185, by controlling fans 178
and 188, or a combination thereof, as examples. In various
embodiments, these different modes of operation can be performed in
any order depending, for example, on demand for heating or cooling
of the space and for heating of the water. Further, a number of
embodiments include or perform fewer than all of the modes of
operation or acts of method 400 shown in FIG. 4 and described
herein. For example, some embodiments omit or do not require act
405, act 406, or both. In a number of embodiments, method 300,
shown in FIG. 3, for instance, in one of the embodiments described
herein, can be performed in act 401, act 402, or both, for example.
Moreover, in certain embodiments, method 300, shown in FIG. 3, for
instance, in one of the embodiments described herein, can be
performed in act 405, act 406, or both, for another example (e.g.,
in embodiments in which the water heat exchanger can be isolated or
can be the "particular heat exchanger"). As described, however, in
embodiments where method 300 is performed in act 405, act 406, or
both, additional valves, refrigerant conduit, or both, may be
required over what is shown in FIGS. 1 and 2 to isolate and bypass
water heat exchanger 190. In other embodiments, however, act 405,
406, or both, can be performed (e.g., with the apparatus shown in
FIGS. 1 and 2) by turning off water pump 198 (e.g., circulating
domestic hot water).
[0080] In a number of embodiments, in at least one of the first
mode or the second mode, the method (e.g., 400) includes managing
the refrigerant charge, for example, in accordance with one of the
methods described herein (e.g., 300). In certain embodiments, the
first mode of operation, the second mode of operation, or both, may
be as previously described, for instance. Even further, in a number
of embodiments, during the method (e.g., 400) of heating and
cooling the space, the rejecting of heat to the outdoor air or to a
heat source/sink (e.g., in act 403 or 405) is accomplished using
the outdoor heat exchanger (e.g., 170), the extracting of heat from
the outdoor air or from the heat source/sink (e.g., in act 402,
404, or 406) is accomplished using the outdoor heat exchanger
(e.g., 170), the heating of water (e.g., the domestic hot water) is
accomplished using the water heat exchanger (e.g., 190), or a
combination thereof, as examples. Even further still, in various
embodiments, the cooling of the space (e.g., in act 401, 403, or
405) is accomplished using the indoor heat exchanger (e.g., 180),
the heating the space (e.g., in act 404 or 406) is accomplished
using the indoor heat exchanger (e.g., 180), or both.
[0081] Further embodiments include various heat pumps (e.g., 100)
that heat or cool a space and that also heat water. Such a heat
pump can include, for example, an outdoor heat exchanger (e.g.,
170) that transfers heat between refrigerant and outdoor air or a
heat source/sink, an indoor heat exchanger (e.g., 180) that
transfers heat between the refrigerant and indoor air, and a water
heat exchanger (e.g., 190) that transfers heat from the refrigerant
to water, such as domestic hot water. Further, such embodiments can
include, as further examples, a compressor (e.g., 160), at least
one expansion device (e.g., 175, 185, or both), and a digital
controller (e.g., 130), for instance. Moreover, in a number of
embodiments, the digital controller can include, for example,
programming instructions (e.g., 135) to manage refrigerant charge,
for instance, in accordance with a method described herein.
[0082] Various methods include one or more acts of manufacturing,
obtaining or providing certain structure described herein, as other
examples. Examples include an act of manufacturing, obtaining or
providing a heat pump (e.g., 100) that heats and cools a space
(e.g., within a building) and that also heats water (e.g., domestic
hot water). A number of embodiments include an act of
manufacturing, obtaining or providing an improved system to manage
refrigerant charge or a heat pump having such a system. Certain
embodiments include one or more acts of manufacturing, obtaining or
providing an outdoor heat exchanger (e.g., 170) that transfers heat
between refrigerant and outdoor air or a heat source/sink,
manufacturing, obtaining or providing an indoor heat exchanger
(e.g., 180) that transfers heat between the refrigerant and indoor
air, and manufacturing, obtaining or providing a water heat
exchanger (e.g., a domestic hot water heat exchanger, for instance,
190) that transfers heat from the refrigerant to water. Further,
some embodiments include one or more acts of manufacturing,
obtaining or providing a compressor (e.g., 160), manufacturing,
obtaining or providing an outdoor expansion device (e.g., 175),
manufacturing, obtaining or providing an indoor expansion device
(e.g., 185), manufacturing, obtaining or providing a refrigerant
management valve (e.g., 150), manufacturing, obtaining or providing
a reversing valve (e.g., 140), manufacturing, obtaining or
providing various refrigerant conduits, or a combination thereof,
as examples.
[0083] Further still, a number of embodiments include one or more
acts of manufacturing, obtaining or providing a first refrigerant
conduit (e.g., 101) connecting an outdoor heat exchanger (e.g.,
170) to an outdoor expansion device (e.g., 175), manufacturing,
obtaining or providing a second refrigerant conduit (e.g., 102)
connecting an indoor heat exchanger (e.g., 180) to an indoor
expansion device (e.g., 185), manufacturing, obtaining or providing
a third refrigerant conduit (e.g., 103) connecting the outdoor
expansion device (e.g., 175) to the indoor expansion device (e.g.,
185), or a combination thereof, for example. Moreover, particular
embodiments include, for instance, one or more of acts of
manufacturing, obtaining or providing a fourth refrigerant conduit
(e.g., 104) connecting a discharge port (e.g., 164) on a compressor
(e.g., 160) to a water heat exchanger or domestic hot water heat
exchanger (e.g., 190), manufacturing, obtaining or providing a
fifth refrigerant conduit (e.g., 105) connecting the water heat
exchanger or domestic hot water heat exchanger (e.g., 190) to a
refrigerant management valve (e.g., 150), manufacturing, obtaining
or providing a sixth refrigerant conduit (e.g., 106) connecting the
refrigerant management valve (e.g., 150) to a reversing valve
(e.g., 140), or a combination thereof. Further, some methods
include one or more of the acts of manufacturing, obtaining or
providing a seventh refrigerant conduit (e.g., 107) connecting the
reversing valve (e.g., 140) to the outdoor heat exchanger (e.g.,
170), manufacturing, obtaining or providing an eighth refrigerant
conduit (e.g., 108) connecting the reversing valve (e.g., 140) to
the indoor heat exchanger (e.g., 180), manufacturing, obtaining or
providing a ninth refrigerant conduit (e.g., 109) connecting the
refrigerant management valve (e.g., 150) to a refrigerant conduit,
for instance, the third refrigerant conduit (e.g., 103),
manufacturing, obtaining or providing a tenth refrigerant conduit
(e.g., 110 connecting the reversing valve (e.g., 140) to an inlet
port (e.g., 162) on the compressor (e.g., 160), or a combination
thereof, for example.
[0084] FIGS. 5 and 6 illustrate further embodiments that include a
refrigerant recovery valve (e.g., 151). In a number of embodiments,
the refrigerant recovery valve opens to remove idle (e.g., liquid)
refrigerant from the particular heat exchanger (i.e., that is not
being used to exchange heat) to manage refrigerant charge in the
heat pump (e.g., in act 401, 402, or both shown in FIG. 4). In some
embodiments, the refrigerant recovery valve is opened to remove
refrigerant from the particular heat exchanger, for example, that
has leaked into the particular heat exchanger through the reversing
valve, through the refrigerant management valve, through one or
more expansion valves, through one or more check valves that are
parallel to the one or more expansion valves, or a combination
thereof. Further, in a number of embodiments, the refrigerant
recovery valve is opened during operation of the heat pump to
optimize, for example, refrigerant charge in the heat pump, for
instance, when one or more operating conditions has changed, for
example, when water temperature, outdoor air temperature, space
temperature, demand for hot water, or demand for space heating or
cooling has changed.
[0085] Further still, in particular embodiments, the refrigerant
recovery valve is opened, once the particular heat exchanger has
been isolated against additional refrigerant flowing into the
particular heat exchanger (e.g., in act 302 shown in FIG. 3), to
remove refrigerant from the particular heat exchanger, rather than
performing the act (e.g., 301) of delivering hot refrigerant gas to
the particular heat exchanger to drive the liquid refrigerant out
of the particular heat exchanger. In embodiments that do not
perform the act (e.g., 301) of delivering hot refrigerant gas to
the particular heat exchanger to drive the liquid refrigerant out
of the particular heat exchanger, however, the refrigerant recovery
valve (e.g., 151) the refrigerant management conduit (e.g., 111 and
112), or a combination thereof, may need to be larger to remove
refrigerant from the unused or "particular" heat exchanger more
quickly in order to obtain a desirable refrigerant charge in the
active system of the heat pump within a desirable amount of
time.
[0086] In some embodiments, incorporation of the act (e.g., 301) of
delivering hot refrigerant gas to the particular heat exchanger to
drive the liquid refrigerant out of the particular heat exchanger
obtains a desirable refrigerant charge in the active system of the
heat pump more quickly, with a smaller refrigerant recovery valve
(e.g., 151), with a smaller refrigerant recovery conduit (e.g., 111
and 112), or a combination thereof. In a number of embodiments,
however, inclusion of a refrigerant recovery valve (e.g., 151) and
refrigerant recovery conduit (e.g., 111 and 112), for example,
allows the appropriate refrigerant charge in the active system of
the heat pump to be maintained, adjusted, or optimized, for
example, while the heat pump is operating (e.g., in act 303)
without interrupting the operation of the heat pump to perform the
act (e.g., 301) of delivering hot refrigerant gas to the particular
heat exchanger to drive the liquid refrigerant out of the
particular heat exchanger.
[0087] In various embodiments, when the refrigerant recovery valve
(e.g., 151) is open, the particular heat exchanger is connected,
through the refrigerant recovery valve, to the suction side of the
compressor (e.g., inlet port 162 of compressor 160). In a number of
embodiments, the refrigerant recovery valve connects the unused
coil or heat exchanger to the suction side of the active (e.g.,
full-condensing) water heating system, and when the refrigerant
recovery valve is opened, refrigerant in the unused heat exchanger
is sucked into the active system (e.g., the heat pump minus the
unused or "particular" heat exchanger) to make up refrigerant
charge losses. In different embodiments, the refrigerant recovery
valve allows for shortening or eliminating of the act of delivering
hot refrigerant gas to the unused heat exchanger to drive the
liquid refrigerant out of the unused heat exchanger. Moreover, in
various embodiments, the refrigerant conduits, valves, and
connections are arranged such that a single refrigerant recovery
valve (e.g., 151) can recover refrigerant from, at different times
(e.g., modes of operation 401 and 402), both the indoor heat
exchanger (e.g., 180) and the outdoor heat exchanger (e.g., 190),
depending on which heat exchanger is being used to transfer
heat.
[0088] FIGS. 5 and 6 illustrate a further example of a heat pump
that heats or cools a space and also heats water. FIG. 5
illustrates heat pump 500 operating in a cooling mode (i.e.,
cooling the space, for instance, act 401). FIG. 6, in contrast to
FIG. 5, illustrates heat pump 500 operating in a mode that does not
cool the space (e.g., act 402). Rather, in the mode of operation of
FIG. 6, heat is extracted from the environment, in particular, from
the outdoor air or from the ground. Heat pump 500 can be similar to
heat pump 100 described above, except as described herein. Further,
many of the components of heat pump 500 can be the same as
corresponding components of heat pump 100, and use the same
reference numbers in the figures and description herein.
[0089] In the embodiment illustrated, heat pump 500 includes
outdoor heat exchanger 170 that transfers heat between refrigerant
and outdoor air or a heat source/sink, indoor heat exchanger 180
that transfers heat between the refrigerant and indoor air, and
water heat exchanger 190 that transfers heat from the refrigerant
to water (e.g., domestic hot water). Further, heat pump 500
includes compressor 160, outdoor expansion device 175, indoor
expansion device 185 (various embodiments include at least one
expansion device), refrigerant management valve 150, reversing
valve 140, and various refrigerant conduits.
[0090] Specifically, in the embodiment shown, these refrigerant
conduits include first refrigerant conduit 101 connecting outdoor
heat exchanger 170 to outdoor expansion device 175, second
refrigerant conduit 102 connecting indoor heat exchanger 180 to
indoor expansion device 185, third refrigerant conduit 103
connecting outdoor expansion device 175 to indoor expansion device
185, and fourth refrigerant conduit 104 connecting discharge port
164 on compressor 160 to water heat exchanger 190. Further, in the
embodiment depicted, these refrigerant conduits include, fifth
refrigerant conduit 105 connecting water heat exchanger 190 to
refrigerant management valve 150, sixth refrigerant conduit 106
connecting refrigerant management valve 150 to reversing valve 140,
and seventh refrigerant conduit 107 connecting reversing valve 140
to outdoor heat exchanger 170. Further still, in the embodiment
shown, these refrigerant conduits include, eighth refrigerant
conduit 108 connecting reversing valve 140 to indoor heat exchanger
180, ninth refrigerant conduit 109 connecting refrigerant
management valve 150 to third refrigerant conduit 103, and tenth
refrigerant conduit 110 connecting reversing valve 140 to inlet
port 162 on compressor 160.
[0091] In some embodiments, conduit 109 can be short and conduit
103 can extend close to or completely to refrigerant management
valve 150. In some embodiments, conduit 109 is essentially a
connection (e.g., a tee connection) of conduit 103 to refrigerant
management valve 150, but as used herein, such a connection is
still considered to be a conduit. Similar configurations are
permissible for other conduits that are described as connecting to
a different named conduit herein, provided the other conduit does
not contain a valve or any other component other than the
passageway of the conduit itself that would preclude such a
connection or result in a different circuit. In other words, a
refrigerant conduit, as used herein, does not necessarily have a
particular length, provided the refrigerant conduit connects the
components identified. Further, conduits described herein that
connect to another conduit can connect to either an end or a
midpoint of the other conduit, unless indicated otherwise or other
components preclude such a connection.
[0092] In various embodiments, a heat pump (e.g., 500) includes a
digital controller (e.g., 130), that includes, in a number of
embodiments, programming instructions (e.g., 135) to manage
refrigerant charge, for example, by controlling (e.g., closing,
when appropriate, for instance, in act 302 shown in FIG. 3) at
least one expansion device or valve, for example, the outdoor
expansion device (e.g., 175), the indoor expansion device (e.g.,
185), or both. Further, in particular embodiments, such a heat pump
(e.g., 500) further includes a digital controller (e.g., 130)
having programming instructions (e.g., 135) to manage refrigerant
charge during conditions under which a particular heat exchanger is
not needed for transferring heat, by delivering refrigerant gas to
the particular heat exchanger and driving liquid refrigerant out of
the particular heat exchanger (e.g., instructions to perform act
301 shown in FIG. 3). In different embodiments, or in different
modes of operation of the same heat pump, as examples, the
particular heat exchanger can be either the outdoor heat exchanger
(e.g., 170) or the indoor heat exchanger (e.g., 180). Further, in
some embodiments, the digital controller (e.g., 130) can have
programming instructions (e.g., 135) to, while the refrigerant gas
is in the particular heat exchanger, isolate the particular heat
exchanger (e.g., act 302), for example, against additional
refrigerant flowing into the particular heat exchanger, and while
the particular heat exchanger is isolated against additional
refrigerant flowing into the particular heat exchanger, to operate
the heat pump (e.g., 500), including running the compressor (e.g.,
160) and heating the water at the water heat exchanger (e.g., 190).
In certain embodiments, the digital controller (e.g., 130) further
includes programming instructions (e.g., 135) to isolate the
particular heat exchanger by controlling the refrigerant management
valve (e.g., 150), and to isolate the particular heat exchanger
(e.g., in act 302) by controlling the outdoor expansion device
(e.g., 175) or the indoor expansion device (e.g., 185) (e.g.,
depending on which heat exchanger is being used to transfer
heat).
[0093] In the embodiment illustrated in FIGS. 1, 2, 5 and 6, third
refrigerant conduit 103 directly connects outdoor expansion device
175 to indoor expansion device 185. As used herein, "directly
connects", when referring to refrigerant conduits, means that the
conduit connects the two components indicated without an
electrically operated valve located within that conduit between the
ends of the conduit. Further, in the embodiment shown, fourth
refrigerant conduit 104 directly connects compressor 160, or
specifically discharge port 164 on compressor 160, to water heat
exchanger 190 (i.e., to water heat exchanger inlet 192 of water
heat exchanger 190). Further still, in the embodiment shown, fourth
refrigerant conduit 104 exclusively connects discharge port 164 on
compressor 160 to water heat exchanger 190. As used herein,
"exclusively connects", when referring to refrigerant conduits,
means connects without any branches off of the refrigerant conduit.
An example of a branch, as used herein, is a tee connection, where
one refrigerant conduit connects with a tee to another refrigerant
conduit. For example, in the embodiment illustrated, conduit 109 is
a branch off of conduit 103, and, as used herein, conduit 103 does
not exclusively connect outdoor expansion device 175 to indoor
expansion device 185. Further, as used herein, a branch can be at
the end of a conduit, provided the branch is fluidly connected to
the conduit at the end of the conduit without passing through
either component of the two components indicated that the
refrigerant conduit is stated herein to connect.
[0094] Even further, in the embodiment shown in FIGS. 1, 2, 5, and
6, sixth refrigerant conduit 106 directly connects refrigerant
management valve 150 to reversing valve 140. Even further still, in
the embodiment shown in FIGS. 1 and 2, sixth refrigerant conduit
106 exclusively connects refrigerant management valve 150 to
reversing valve 140. In the embodiment shown in FIGS. 5 and 6,
however, sixth refrigerant conduit 106 does not exclusively connect
refrigerant management valve 150 to reversing valve 140, because
refrigerant conduit 111 branches (e.g., tees) off from refrigerant
conduit 106. Similarly, in the embodiment shown in FIGS. 1, 2, 5,
and 6, tenth refrigerant conduit 110 directly connects reversing
valve 140 to inlet port 162 on compressor 160. Even further still,
in the embodiment shown in FIGS. 1 and 2, tenth refrigerant conduit
110 exclusively connects reversing valve 140 to inlet port 162 on
compressor 160. As used herein, the accumulator 120 in tenth
refrigerant conduit 110 is considered to be part of refrigerant
conduit 110. In the embodiment shown in FIGS. 5 and 6, however,
tenth refrigerant conduit 110 does not exclusively connect
reversing valve 140 to inlet port 162 on compressor 160, because
refrigerant conduit 112 branches (e.g., tees) off from refrigerant
conduit 110.
[0095] In various embodiments, the third refrigerant conduit
directly connects the outdoor expansion device to the indoor
expansion device, the fourth refrigerant conduit directly connects
the discharge port on the compressor to the water heat exchanger,
and the sixth refrigerant conduit directly connects the refrigerant
management valve to the reversing valve. Further, in the embodiment
illustrated in FIGS. 1, 2, 5, and 6, first refrigerant conduit 101
directly connects and exclusively connects outdoor heat exchanger
170 to outdoor expansion device 175, second refrigerant conduit 102
directly connects and exclusively connects indoor heat exchanger
180 to indoor expansion device 185, and fifth refrigerant conduit
105 directly connects and exclusively connects water heat exchanger
190 to refrigerant management valve 150. Even further, in the
embodiment shown in FIGS. 1, 2, 5, and 6, seventh refrigerant
conduit 107 directly connects and exclusively connects reversing
valve 140 to outdoor heat exchanger 170, eighth refrigerant conduit
108 directly connects and exclusively connects reversing valve 140
to indoor heat exchanger 180, and ninth refrigerant conduit 109
directly connects and exclusively connects refrigerant management
valve 150 to third refrigerant conduit 103.
[0096] In various embodiments, the heat pump (e.g., 500) further
includes a refrigerant recovery conduit connecting the sixth
refrigerant conduit (e.g., 106) to the tenth refrigerant conduit
(e.g., 110). Further, a number of embodiments include a refrigerant
recovery valve (e.g., 151) located in the refrigerant recovery
conduit. In various embodiments, a refrigerant recovery valve, a
refrigerant recovery conduit, or both, delivers refrigerant from
the unused heat exchanger to the active system at the compressor
inlet. FIGS. 5 and 6 illustrate an example. In the embodiment
illustrated, heat pump 500 includes refrigerant recovery valve SV1
or 151, eleventh refrigerant conduit 111 connecting sixth
refrigerant conduit 106 to refrigerant recovery valve 151, and
twelfth refrigerant conduit 112 connecting refrigerant recovery
valve 151 to tenth refrigerant conduit 110. Other embodiments can
include a subcombination of these components. In a number of
embodiments, refrigerant recovery valve 151 is a two-way solenoid
valve, for example. In various embodiments, refrigerant recovery
valve 151 is a valve controlled by an electronic board that opens
and closes the refrigerant path (e.g., from refrigerant conduit 111
to refrigerant conduit 112) automatically (e.g., under the control
of controller 130). In some embodiments, refrigerant recovery valve
151 is (e.g., except when opening or closing) held either fully
open or fully closed, and refrigerant recovery valve 151,
refrigerant conduit 111 twelfth refrigerant conduit 112, or a
combination thereof, is sized to provide the appropriate amount of
flow. In other embodiments, refrigerant recovery valve 151 can be a
throttling valve that is opened sufficiently to provide the
appropriate amount of flow, and is routinely held in such a
partially open position.
[0097] In some embodiments, the refrigerant recovery conduit (e.g.,
refrigerant conduit 111, refrigerant recovery valve 151,
refrigerant conduit 112, or a combination thereof) includes an
internal dimension (e.g., a diameter) that provides a refrigerant
flow rate through the refrigerant recovery conduit that is less
than one tenth of a rated refrigerant flow rate of the compressor
(e.g., 160) at a rated pressure of the compressor. In other
embodiments, as other examples, the refrigerant recovery conduit
includes an internal dimension that provides a refrigerant flow
rate through the refrigerant recovery conduit that is less than one
quarter, one fifth, one eighth, one 20.sup.th, one 30.sup.th one
50.sup.th, one 75.sup.th, one 100.sup.th, one 150.sup.th, one
200.sup.th, one 300.sup.th, one 500.sup.th, 1000.sup.th, one
2000.sup.th, one 3000.sup.th, one 5000.sup.th, or one 10,000.sup.th
of the rated refrigerant flow rate of the compressor at the rated
pressure of the compressor. Such an internal dimension can be, for
example, the inside dimension (e.g., inside diameter) of an orifice
or of a capillary tube, as examples. In some embodiments, the
refrigerant recovery valve (e.g., 151) is omitted and this internal
dimension is sized fairly small such that flow through the
refrigerant recovery conduit occurs at all times and is small
enough so as to be tolerable (e.g., negligible) even when not
needed. Use of a refrigerant recovery valve (e.g., 151), however,
can provide control over the refrigerant charge (e.g., in act 401,
402, or both) that is faster, more complete, more stable, or a
combination thereof, in a number of embodiments, and can also
result in a heat pump that is more efficient, including, for
example, in one or more modes of operation (e.g., act 403, 404,
405, 406, or a combination thereof) where all of the heat
exchangers (e.g., 170, 180, and 190) are being used to transfer
heat.
[0098] In a number of embodiments, the heat pump (e.g., 500)
includes a digital controller (e.g., 130) having programming
instructions (e.g., 135) to manage refrigerant charge during
conditions under which a particular heat exchanger is not needed
for transferring heat, by opening the refrigerant recovery valve
(e.g., 151) and thereby removing idle refrigerant from the
particular heat exchanger (e.g., through reversing valve 140, and
one of refrigerant conduit 107 or 108, depending on which heat
exchanger 170 or 180 is not needed for transferring heat). In the
embodiment illustrated, the idle refrigerant is removed from the
particular heat exchanger (e.g., 170 or 180) through eleventh
refrigerant conduit 111, through refrigerant recovery valve 151,
and through twelfth refrigerant conduit 112.
[0099] Further, the idle refrigerant is delivered from the
particular heat exchanger (e.g., 170 or 180) to compressor 160
(i.e., through inlet port 162). Further still, while refrigerant
recovery valve 151 is open, the heat pump is operated, including
running compressor 160 and heating the water at water heat
exchanger 190. In the two different modes of operation shown in
FIGS. 5 and 6, the particular heat exchanger is either outdoor heat
exchanger 170 or indoor heat exchanger 180. In the mode of
operation shown in FIG. 5, the particular heat exchanger is outdoor
heat exchanger 170, and in the mode of operation shown in FIG. 6,
the particular heat exchanger is indoor heat exchanger 180. Even
further, in the embodiment illustrated in FIGS. 5, and 6, eleventh
refrigerant conduit 111 directly connects and exclusively connects
refrigerant conduit 106 to refrigerant recovery valve 151, and
twelfth refrigerant conduit 112 directly connects and exclusively
connects refrigerant recovery valve 151 to refrigerant conduit
110.
[0100] In some embodiments of a heat pump, the outdoor heat
exchanger includes a ground loop. Outdoor heat exchanger 170, shown
in FIGS. 1, 2, 5, and 6, can be or include a ground loop, for
example, in heat exchanger 100 or 500, as examples. As used herein,
the term "ground loop" includes systems where the refrigerant
tubing is routed through the ground and systems where heat is
exchanged between the refrigerant and a secondary liquid loop, such
a glycol, that is circulated through the ground. Further, as used
herein, the term "ground loop" includes systems that exchange heat
with ground water as well as systems that exchange heat with earth
or rock.
[0101] Other embodiments include (e.g., among other things) various
combinations or subcombinations of the above components. Examples
include a heat pump (e.g., 500) that alternately heats and cools a
space and also heats water, that includes an outdoor heat exchanger
(e.g., 170) that transfers heat between refrigerant and outdoor air
or a heat source/sink, an indoor heat exchanger (e.g., 180) that
transfers heat between the refrigerant and indoor air, and a water
heat exchanger (e.g., 190) that transfers heat from the refrigerant
to water. Such embodiments can further include a compressor (e.g.,
160) that compresses the refrigerant, the compressor having an
inlet port (e.g., 162) and a discharge port (e.g., 164), a
refrigerant management valve (e.g., 150), a reversing valve (e.g.,
140) that switches the heat pump between a cooling mode wherein the
space is cooled by the heat pump and a heating mode wherein the
space is not cooled by the heat pump, and a refrigerant recovery
valve (e.g., 151).
[0102] In a number of embodiments, such a heat pump (e.g., 500)
includes various refrigerant conduits. These refrigerant conduits
can include, for example, a fourth refrigerant conduit (e.g., 104),
for example, connecting or directly connecting (e.g., exclusively
connecting) the discharge port (e.g., 164) on the compressor (e.g.,
160) to the water heat exchanger (e.g., 190, for instance, at water
heat exchanger inlet 192), a sixth refrigerant conduit (e.g., 106)
connecting (e.g., directly connecting) the refrigerant management
valve (e.g., 150) to the reversing valve (e.g., 140), and a tenth
refrigerant conduit (e.g., 110) connecting (e.g., directly
connecting) the reversing valve (e.g., 140) to the inlet port
(e.g., 162) on the compressor (e.g., 160). Further, various
embodiments include a refrigerant recovery conduit (e.g., 111 and
112 combined) connecting the sixth refrigerant conduit (e.g., 106)
to the tenth refrigerant conduit (e.g., 110). In a number of
embodiments, the refrigerant recovery valve (e.g., 151) is located
in the refrigerant recovery conduit (e.g., between eleventh
refrigerant conduit 111 and twelfth refrigerant conduit 112).
[0103] As used herein, the terms "first," "second," "third,"
"fourth," and the like in the description and in the claims, are
identifiers used for distinguishing between similar elements and
not necessarily for describing a particular (e.g., sequential or
chronological) order or arrangement. It is to be understood that
the terms so used are interchangeable under appropriate
circumstances. Further, as an example, an embodiment described as
having a fourth refrigerant conduit, for example, does not
necessarily include or require the first, second, or third
refrigerant conduit, as described herein. Similarly, an embodiment
described as having the fourth, sixth, and tenth refrigerant
conduits does not necessarily include or require the fifth,
seventh, eighth, or ninth refrigerant conduits, as described
herein.
[0104] In various embodiments, the heat pump has two cooling modes
where the space is cooled by the heat pump and the water is heated,
the mode illustrated in FIG. 5 (e.g., act 401 of FIG. 4), and a
mode where heat is also rejected through outdoor heat exchanger 170
(e.g., act 403). Further, in a number of embodiments, the heat pump
has two water heating modes where the space is not cooled by the
heat pump, the mode illustrated in FIG. 6 (e.g., act 402) where
indoor heat exchanger 180 is not used, and a mode where indoor heat
exchanger 180 is used to heat the space (e.g., act 404). In various
embodiments, in all four of these modes, water can be heated at
water heat exchanger 190. Further, a number of embodiments include
two other modes where water is not heated, one where the space is
cooled (e.g., act 405) and another where the space is heated (e.g.,
act 406).
[0105] In some embodiments, the heat pump (e.g., 500) further
including a digital controller (e.g., 130) that includes
programming instructions (e.g., 135) to manage refrigerant charge
during conditions under which a particular heat exchanger is not
needed for transferring heat, by opening the refrigerant recovery
valve (e.g., 151 and thereby removing idle refrigerant from the
particular heat exchanger through the refrigerant recovery conduit
(e.g., 111 and 112) and through the refrigerant recovery valve
(e.g., 151), and delivering the idle refrigerant from the
particular heat exchanger to the compressor (e.g., 160, via inlet
port 162), and while the refrigerant recovery valve (e.g., 151) is
open, operating the heat pump (e.g., 500), including running the
compressor (e.g., 160) and heating the water at the water heat
exchanger (e.g., 190). In different modes of operation (e.g., shown
in FIGS. 5 and 6), the particular heat exchanger is either the
outdoor heat exchanger (e.g., 170) or the indoor heat exchanger
(e.g., 180). Further, in some embodiments, the outdoor heat
exchanger (e.g., 170) includes a ground loop.
[0106] Further, in various embodiments, such a heat pump can
include a combination of other components, including refrigerant
conduits, described herein. All conceivable combinations are
contemplated. For example, in some embodiments, the heat pump
further includes an outdoor expansion device (e.g., 175), an indoor
expansion device (e.g., 185), and at least six of: the first,
second, third, fifth, seventh, eighth, and ninth refrigerant
conduits described herein. Other embodiments include a different
number (i.e., rather than six) of these refrigerant conduits. For
example, in some embodiments, the heat pump further includes at
least one, two, three, four, five, or seven of the first, second,
third, fifth, seventh, eighth, and ninth refrigerant conduits
described herein.
[0107] In various embodiments, the first refrigerant conduit (e.g.,
101) connects the outdoor heat exchanger to the outdoor expansion
device, the second refrigerant conduit (e.g., 102) connects the
indoor heat exchanger to the indoor expansion device, the third
refrigerant conduit (e.g., 103) connects the outdoor expansion
device to the indoor expansion device, the fifth refrigerant
conduit (e.g., 105) connects the water heat exchanger to the
refrigerant management valve, the seventh refrigerant conduit
(e.g., 107) connects the reversing valve to the outdoor heat
exchanger, the eighth refrigerant conduit (e.g., 108) connects the
reversing valve to the indoor heat exchanger, the ninth refrigerant
conduit (e.g., 109) connects the refrigerant management valve to
the third refrigerant conduit, or a combination thereof. In some
embodiments, some such connections can be direct or exclusive, as
described herein, shown in the figures, or both.
[0108] In a number of embodiments, the refrigerant management valve
(e.g., 150) is a three-way valve, the reversing valve (e.g., 140)
is a four-way valve, the refrigerant recovery valve (e.g., 151) is
a two-way valve, or a combination thereof. In some embodiments,
however, the refrigerant management valve can consist of two (2)
two-way valves, as another example. Further, in some embodiments,
refrigerant management valve 150 and refrigerant recovery valve 151
are combined into one valve that performs all of the function
described herein. Further still, as used herein, embodiments that
separately identify a refrigerant management valve and refrigerant
recovery valve include embodiments where these two valves are
combined provided the functions recited by that embodiment are
performed by that combined valve. Even further, in such an
embodiment having a combined refrigerant management and refrigerant
recovery valve, refrigerant conduit 111 may connect to refrigerant
conduit 106 at an end of refrigerant conduit 106.
[0109] In various embodiments, in a first mode of operation, the
refrigerant management valve (e.g., 150) operates (e.g., as shown
in FIG. 5) to isolate the outdoor heat exchanger (e.g., 170), and
in a second mode of operation, the refrigerant management valve
(e.g., 150) operates (e.g., as shown in FIG. 6) to isolate the
indoor heat exchanger (e.g., 180). In the embodiment shown (e.g.,
heat pump 500), which of these modes of operation (i.e., first or
second mode of operation) the heat pump is operating in, (e.g., at
a particular time) is determined by four-way valve or reversing
valve 140), but the one refrigerant management valve (e.g., 150),
in various embodiments, operates to isolate either heat exchanger
(i.e., 170 or 180).
[0110] Moreover, in a number of embodiments, the refrigerant
management valve (e.g., 150) has a first position and a second
position, and when the refrigerant management valve (e.g., 150) is
in the first position, the heat pump (e.g., 500) uses both the
outdoor heat exchanger (e.g., 170) and the indoor heat exchanger
(e.g., 180) to transfer heat, and when the refrigerant management
valve (e.g., 150) is in the second position, the heat pump uses
only one of the outdoor heat exchanger (e.g., 170) or the indoor
heat exchanger (e.g., 180) to transfer heat. For example, in the
embodiment illustrated, in the first position, refrigerant
management valve 150 is positioned or switched such that
refrigerant conduit 105 is connected through refrigerant management
valve 150 to refrigerant conduit 106, and refrigerant conduit 109
is blocked by refrigerant management valve 150 from refrigerant
conduit 105 or refrigerant conduit 106. In comparison, in the
second position, refrigerant management valve 150 is positioned or
switched such that refrigerant conduit 105 is connected through
refrigerant management valve 150 to refrigerant conduit 109, and
refrigerant conduit 106 is blocked by refrigerant management valve
150 from refrigerant conduit 105 or refrigerant conduit 109.
[0111] In various embodiments, for example, when the refrigerant
management valve (e.g., 150) is in the first position, the space is
conditioned (i.e., heated or cooled via indoor heat exchanger 180)
and the water is heated (e.g., at water heat exchanger 190) by
desuperheating, (e.g., in some embodiments, if needed, for
instance, acts 403, 404, 405, and 406 shown in FIG. 4). Further,
when the refrigerant management valve (e.g., 150) is in the second
position, in a number of embodiments, the refrigerant is (e.g.,
fully) condensed in the water heat exchanger (e.g., rather than
just being desuperheated), either in combination with space cooling
(e.g., via indoor heat exchanger 180) or with extraction of heat
(e.g., via outdoor heat exchanger 170) from the outdoor air or heat
source/sink (e.g., ground). In a number of embodiments, this second
position corresponds to or causes acts 401 and 402 (i.e., one at a
time, for example, depending on the position of reversing valve
140).
[0112] In various embodiments, in a first mode of operation (e.g.,
act 401 shown in FIG. 4), the refrigerant recovery valve (e.g.,
151) opens to draw refrigerant from the outdoor heat exchanger
(e.g., 170) to the inlet port (e.g., 162) on the compressor (e.g.,
160), and in a second mode of operation (e.g., act 402), the
refrigerant recovery valve (e.g., 151) opens to draw refrigerant
from the indoor heat exchanger (e.g., 180) to the inlet port (e.g.,
162) on the compressor (e.g., 160). Further, in some embodiments,
in the first mode of operation (e.g., act 401), the heat pump
(e.g., 500) heats the domestic hot water with the water heat
exchanger (e.g., 190) while cooling the space with the indoor heat
exchanger (e.g., 180), including condensing the refrigerant in the
water heat exchanger (e.g., 190) and managing refrigerant charge in
the heat pump (e.g., 500) by removing liquid refrigerant from the
outdoor heat exchanger (e.g., 170). Further still, in some
embodiments, in the second mode of operation (e.g., act 402), the
heat pump heats the domestic hot water with the water heat
exchanger (e.g., 190) while extracting heat from the outdoor air or
from the heat source/sink with the outdoor heat exchanger (e.g.,
170) without heating the space with the indoor heat exchanger
(e.g., 180) and without cooling the space with the indoor heat
exchanger (e.g., 180), including condensing the refrigerant in the
water heat exchanger (e.g., 190) and managing refrigerant charge in
the heat pump by removing liquid refrigerant from the indoor heat
exchanger (e.g., 180).
[0113] Even further, in some embodiments, in a third mode of
operation (e.g., act 403 in FIG. 4), the heat pump (e.g., 500)
heats the domestic hot water with the water heat exchanger (e.g.,
190) while cooling the space with the indoor heat exchanger (e.g.,
180) and while rejecting heat to the outdoor air or to the heat
source/sink with the outdoor heat exchanger (e.g., 170), including
desuperheating the refrigerant in the water heat exchanger (e.g.,
190) and condensing the refrigerant in the outdoor heat exchanger
(e.g., 190). Even further still, in some embodiments, in a fourth
mode of operation (e.g., act 404), the heat pump heats the domestic
hot water with the water heat exchanger (e.g., 190) while heating
the space with the indoor heat exchanger (e.g., 180) and while
extracting heat from the outdoor air or from the heat source/sink
with the outdoor heat exchanger (e.g., 190), including
desuperheating the refrigerant in the water heat exchanger (e.g.,
190) and condensing the refrigerant in the indoor heat exchanger
(e.g., 180).
[0114] Various embodiments of methods use a refrigerant recovery
valve (e.g., 151), refrigerant recovery conduit (e.g., 111 and
112), or both. Examples include various methods of managing
refrigerant charge in a heat pump (e.g., 500) that heats or cools a
space and that also heats water, the heat pump including an outdoor
heat exchanger (e.g., 170) that transfers heat between refrigerant
and outdoor air or a heat source/sink, an indoor heat exchanger
(e.g., 180) that transfers heat between the refrigerant and indoor
air, a water heat exchanger (e.g., 190) that transfers heat from
the refrigerant to water, a compressor (e.g., 160), and at least
one expansion device (e.g., 175, 185, or both). Such a method can
include, for example, in any order except where a particular order
is explicitly indicated or otherwise required, at least certain
acts. Such acts can include, for example, during conditions under
which a particular heat exchanger (e.g., 170 or 180) of the heat
pump is not needed for transferring heat, delivering refrigerant
gas to the particular heat exchanger and driving liquid refrigerant
out of the particular heat exchanger (e.g., act 301 shown in FIG.
3).
[0115] Other such acts include, in some embodiments, while the
refrigerant gas is in the particular heat exchanger, isolating the
particular heat exchanger against additional refrigerant flowing
into the particular heat exchanger (e.g., act 302), and while the
particular heat exchanger is isolated against additional
refrigerant flowing into the particular heat exchanger, operating
the heat pump (e.g., 500), including running the compressor (e.g.,
160; e.g., act 303). Further, some such embodiments include an act,
while the particular heat exchanger is isolated against additional
refrigerant flowing into the particular heat exchanger (e.g.,
during act 302), of drawing refrigerant from the particular heat
exchanger to the compressor (e.g., through refrigerant conduit 111,
refrigerant recovery valve 151, refrigerant conduit 112, or a
combination thereof), including running the compressor (e.g.,
160).
[0116] In some embodiments or modes of operation, for example, the
particular heat exchanger is the outdoor heat exchanger (e.g.,
170), and in some embodiments or modes of operation, for instance,
the particular heat exchanger is the indoor heat exchanger (e.g.,
180). Certain embodiments include both of these modes of operation.
Further, in some embodiments, the act of isolating the particular
heat exchanger against additional refrigerant flowing into the
particular heat exchanger (e.g., act 302) includes closing a
particular electronic expansion valve, for example, that is
connected to the particular heat exchanger with a particular
refrigerant conduit. Even further, in some embodiments, the act of
isolating the particular heat exchanger against additional
refrigerant flowing into the particular heat exchanger (e.g., act
302) includes actuating a refrigerant management valve (e.g., 150)
located in a water heater outlet refrigerant conduit (e.g., 105 and
106 combined) that connects the water heat exchanger (e.g., 190) to
a reversing valve (e.g., 140) that is used to switch the heat pump
between a heating mode, in which the heat pump heats the space
(e.g., act 404 or 406), and a cooling mode, in which the heat pump
cools the space (e.g., act 401, 403, or 405), or both. Further
still, in some embodiments, the act of operating the heat pump
(e.g., 500, act 302)) includes keeping the particular electronic
expansion valve (e.g., 175 or 185) closed for at least a majority
of the act of operating the heat pump (e.g., act 303).
[0117] In a number of embodiments, the act of drawing refrigerant
from the particular heat exchanger to the compressor (e.g., 160)
includes opening a refrigerant recovery valve (e.g., 151) located
in a refrigerant recovery conduit (e.g., 111 and 112 combined) that
connects the water heater outlet refrigerant conduit (e.g., 106 or
105 and 106 combined) to a compressor inlet refrigerant conduit
(e.g., 110), wherein the compressor inlet refrigerant conduit
(e.g., 110) connects the reversing valve (e.g., 140) to an inlet
port (e.g., 162) on the compressor. In various embodiments, the
refrigerant recovery conduit (e.g., 111) connects to the water
heater outlet refrigerant conduit between the refrigerant
management valve (e.g., 150) and the reversing valve (e.g., 140)
(e.g., at sixth refrigerant conduit 106).
[0118] Further, some such embodiments include an act of adjusting
the refrigerant charge (e.g., act 304 in FIG. 3) that takes place
after the act (e.g., act 302) of isolating the particular heat
exchanger against additional refrigerant flowing into the
particular heat exchanger (e.g., while the particular heat
exchanger is isolated against additional refrigerant flowing into
it). In some embodiments, the act of adjusting the refrigerant
charge (e.g., act 304) takes place during the act of operating the
heat pump (e.g., act 303), and the act of adjusting the refrigerant
charge (e.g., act 304) includes using, for example, the particular
electronic expansion valve (e.g., 175 or 185, but not both at the
same time) to let refrigerant into the particular heat exchanger
(e.g., 170 or 180 but not both at the same time). Further still, in
some embodiments, the act of adjusting the refrigerant charge
(e.g., act 304) includes monitoring refrigerant subcooling at a
water heat exchanger outlet (e.g., 194, or downstream thereof
before refrigerant subcooling changes significantly) and letting
refrigerant into the particular heat exchanger if the subcooling at
the water heat exchanger outlet exceeds a predetermined subcooling
threshold. Even further, in some embodiments, the act of drawing
refrigerant from the particular heat exchanger to the compressor
(e.g., 160) includes opening a refrigerant recovery valve (e.g.,
151) located in a refrigerant recovery conduit (e.g., 111 and 112
combined) that connects a water heater outlet refrigerant conduit
(e.g., 105, 106, or both) to a compressor inlet refrigerant conduit
(e.g., 110).
[0119] In some embodiments, the heat pump or controller waits a
certain amount of time after the refrigerant recovery valve (e.g.,
151) is closed, or after the refrigerant management valve (e.g.,
150) is operated and the one or more expansion valves are closed
(e.g., 175 and 185) to isolate the particular heat exchanger, while
the heat pump is operating (e.g., act 303), to determine whether
the active system is properly charged. If the active system (e.g.,
heat pump 500 except for the particular heat exchanger) is
overcharged after that amount of time, in a number of embodiments,
the expansion valve (e.g., 175 or 185) is opened, for example, to
reduce the charge in the active system (e.g., act 304). On the
other hand, if the active system is undercharged after that amount
of time (or at a later time, in a number of embodiments) in some
embodiments, the refrigerant recovery valve (e.g., 151) is opened,
for example, to increase the charge in the active system. In
different embodiments, this amount of time can be, for example, 10,
20, 30, 40, 50, 60, 70, 80, 90, 100, 120, 150, 180, 210, 240, or
300 seconds, as examples, or within a range between any two such
amounts of time, as further examples. In certain embodiments that
do not include act 301 described herein of driving liquid
refrigerant from the particular heat exchanger (e.g., by delivering
refrigerant gas to the particular heat exchanger), the refrigerant
recovery valve (e.g., 151) is opened soon (e.g., within 1, 2, 3, 4,
5, 7, 10, 15, 20, 30, 45, or 60 seconds, in different embodiments,)
or immediately after the particular heat exchanger is isolated
(e.g., act 302), for example, anticipating that refrigerant will
need to be removed from the unused or particular heat exchanger in
order to have an appropriate refrigerant charge in the active
system.
[0120] In a number of embodiments, once the refrigerant management
valve (e.g., 150) is opened, the refrigerant management valve
remains open (e.g., under the control of the controller, for
example, 130, via programming instructions 135) until one of the
following occurs: (1) a predetermined time has passed, or (2) a
predetermined measured value is reached, for example, whichever
[i.e., (1) or (2)] occurs first. Such a predetermined time can be,
for example, 2, 5, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, 100,
120, 150, 180, 210, 240, or 300 seconds, as examples, or within a
range between any two such amounts of time, as further examples.
Further, such a predetermined measured value can be, for example, a
pressure or a temperature of the refrigerant with in the heat pump,
as examples.
[0121] Further still, in a number of embodiments, the refrigerant
recovery valve (e.g., 151) is opened during operation of the heat
pump (e.g., 500) to remove refrigerant from the particular heat
exchanger (e.g., 170 or 180), or an expansion valve (e.g., 175 or
185) is opened to let refrigerant into the particular heat
exchanger (e.g., act 304), to optimize, or better optimize, for
example, refrigerant charge in the heat pump, while the heat pump
is operating (e.g., in act 303). For instance, in some embodiments,
refrigerant charge can optimized or adjusted when refrigerant has
leaked into the particular heat exchanger or when one or more
operating conditions has changed, for example, when water
temperature, outdoor air temperature, space temperature, demand for
hot water, or demand for space heating or cooling has changed, or a
combination thereof. Optimization of refrigerant charge, in a
number of embodiments, can improve efficiency, capacity, or both,
of the heat pump. Even further, in certain embodiments, the
refrigerant recovery valve (e.g., 151) is opened during operation
of the heat pump (e.g., 500) to remove refrigerant from the
particular heat exchanger (e.g., 170 or 180), an expansion valve
(e.g., 175 or 185) is opened to let refrigerant into the particular
heat exchanger (e.g., act 304), or both, repeatedly while the heat
pump is operating (e.g., in act 303) to optimize, or better
optimize, for example, refrigerant charge in the heat pump.
[0122] Another example of a method is a method of managing
refrigerant charge in a heat pump (e.g., 500) that includes, for
example, in any order except where a particular order is explicitly
indicated, at least the acts of, during conditions under which a
particular heat exchanger (e.g., 170 or 180) of the heat pump is
not needed for transferring heat, isolating the particular heat
exchanger against additional refrigerant flowing into the
particular heat exchanger (e.g., act 302), and while the particular
heat exchanger is isolated against additional refrigerant flowing
into the particular heat exchanger, drawing refrigerant from the
particular heat exchanger to the inlet port (e.g., 162) of the
compressor (e.g., 160), including running the compressor, wherein
the act of drawing refrigerant from the particular heat exchanger
to the inlet of the compressor includes opening a refrigerant
recovery valve (e.g., 151). In some embodiments, for example, such
a method does not include act 301 described herein.
[0123] In some embodiments, such a method includes monitoring at
least one parameter of the heat pump (e.g., 500), the at least one
parameter indicative of whether the refrigerant charge in the heat
pump is appropriate, and when the refrigerant charge in the heat
pump is appropriate, based on the at least one parameter, closing
the refrigerant recovery valve (e.g., 151). Examples of such a
parameter include temperature, pressure, or both, of the
refrigerant, at one or more particular locations within the heat
pump. In a number of such embodiments, such a method can further
include, after the act of closing the refrigerant recovery valve,
continuing to operate the heat pump, including running the
compressor while the particular heat exchanger is isolated (e.g.,
in act 302) against additional refrigerant flowing into the
particular heat exchanger, and including continuing to monitor the
at least one parameter of the heat pump, and when the refrigerant
charge in the heat pump is below what is appropriate, based on the
at least one parameter, opening the refrigerant recovery valve
(e.g., 151) until the refrigerant charge in the heat pump is
appropriate based on the at least one parameter.
[0124] In some such embodiments, the act of isolating the
particular heat exchanger against additional refrigerant flowing
into the particular heat exchanger (e.g., act 302) includes closing
a particular electronic expansion valve (e.g., 175 or 185) that is
connected to the particular heat exchanger with a particular coil
inlet refrigerant conduit (e.g., 101 or 102). Further, in some
embodiments, the act of isolating the particular heat exchanger
against additional refrigerant flowing into the particular heat
exchanger includes actuating a refrigerant management valve (e.g.,
150) located in a water heater outlet refrigerant conduit (e.g.,
105 and 106) that connects the water heat exchanger (e.g., 190) to
a reversing valve (e.g., 140) that is used to switch the heat pump
between a heating mode (e.g., 402 shown in FIG. 4), in which the
heat pump does not cool the space, and a cooling mode (e.g., 401),
in which the heat pump cools the space.
[0125] In various embodiments, the refrigerant recovery valve
(e.g., 151) is located in a refrigerant recovery conduit (e.g., 111
and 112) that connects the water heater outlet refrigerant conduit
(e.g., 105 and 106, in the embodiment shown, at 106) to a
compressor inlet refrigerant conduit (e.g., 110). In a number of
embodiments, the water heater outlet refrigerant conduit connects
the water heat exchanger (e.g., 190) to a reversing valve (e.g.,
140) that is used to switch the heat pump between a heating mode
(e.g., act 402, 404, or 406), in which the heat pump does not cool
the space, and a cooling mode (e.g., act 401, 403, or 405), in
which the heat pump cools the space, and the compressor inlet
refrigerant conduit (e.g., 110) connects the reversing valve (e.g.,
140) to the inlet (e.g., 162) of the compressor (e.g., 160). In
particular embodiments, the refrigerant recovery conduit (e.g.,
111) connects to the water heater outlet refrigerant conduit
between a refrigerant management valve and the reversing valve
(e.g., at refrigerant conduit 106).
[0126] In some embodiments, the act of monitoring at least one
parameter of the heat pump (e.g., 500) includes monitoring
refrigerant subcooling. Further, in certain embodiments, the act of
monitoring at least one parameter of the heat pump includes
monitoring refrigerant subcooling at a water heat exchanger outlet
(e.g., 194 or at refrigerant conduit 105, refrigerant management
valve 150, refrigerant conduit 109, or refrigerant conduit 103, as
examples).
[0127] Yet another example of a method is a method of heating and
cooling a space and also of heating domestic hot water, the method
including, for example, in any order except where a particular
order is explicitly indicated or otherwise required, at least the
acts of, in a first mode of operation (e.g., act 401), heating the
domestic hot water with the water heat exchanger (e.g., 190) while
cooling the space with the indoor heat exchanger (e.g., 180), the
first mode of operation including condensing the refrigerant in the
water heat exchanger (e.g., 190) and managing refrigerant charge in
the heat pump (e.g., 500) by removing liquid refrigerant from the
outdoor heat exchanger (e.g., 170), and in a second mode of
operation (e.g., act 402), heating the domestic hot water with the
water heat exchanger (e.g., 190) while extracting heat from the
outdoor air or from the heat source/sink with the outdoor heat
exchanger (e.g., 170), without heating the space with the indoor
heat exchanger (e.g., 180) and without cooling the space with the
indoor heat exchanger, the second mode of operation including
condensing the refrigerant in the water heat exchanger (e.g., 190)
and managing refrigerant charge in the heat pump by removing liquid
refrigerant from the indoor heat exchanger (e.g., 180).
[0128] Such a method can also include, in a number of embodiments,
in a third mode of operation (e.g., 403), heating the domestic hot
water with the water heat exchanger (e.g., 190) while cooling the
space with the indoor heat exchanger (e.g., 180) and while
rejecting heat to the outdoor air or to the heat source/sink with
the outdoor heat exchanger (e.g., 170), the third mode of operation
including desuperheating the refrigerant in the water heat
exchanger (e.g., 190) and condensing the refrigerant in the outdoor
heat exchanger (e.g., 170), and in a fourth mode of operation
(e.g., act 404), heating the domestic hot water with the water heat
exchanger (e.g., 190) while heating the space with the indoor heat
exchanger (e.g., 180) and while extracting heat from the outdoor
air or from the heat source/sink with the outdoor heat exchanger
(e.g., 170), the fourth mode of operation including desuperheating
the refrigerant in the water heat exchanger (e.g., 190) and
condensing the refrigerant in the indoor heat exchanger (e.g.,
180).
[0129] In some embodiments, for example, the act in the first mode
of operation (e.g., act 401) of managing refrigerant charge in the
heat pump (e.g., 500) by removing liquid refrigerant from the
outdoor heat exchanger (e.g., 170) includes delivering refrigerant
gas to the outdoor heat exchanger and driving liquid refrigerant
out of the outdoor heat exchanger (e.g., act 301), while the
refrigerant gas is in the outdoor heat exchanger, isolating the
outdoor heat exchanger against additional refrigerant flowing into
the outdoor heat exchanger (e.g., act 302), and while the outdoor
heat exchanger is isolated against additional refrigerant flowing
into the outdoor heat exchanger, operating the heat pump (e.g., act
303), including running the compressor (e.g., 160). Further, in
some embodiments, the act in the second mode of operation (e.g.,
act 402) of managing refrigerant charge in the heat pump by
removing liquid refrigerant from the indoor heat exchanger (e.g.,
180) includes delivering refrigerant gas to the indoor heat
exchanger and driving liquid refrigerant out of the indoor heat
exchanger (e.g., act 301), while the refrigerant gas is in the
indoor heat exchanger, isolating the indoor heat exchanger against
additional refrigerant flowing into the indoor heat exchanger
(e.g., act 302), and while the indoor heat exchanger is isolated
against additional refrigerant flowing into the indoor heat
exchanger, operating the heat pump (e.g., act 303), including
running the compressor.
[0130] Various embodiments of the subject matter described herein
include various combinations of the acts, structure, components,
and features described herein, shown in the drawings, or known in
the art. Moreover, certain procedures may include acts such as
obtaining or providing various structural components described
herein, obtaining or providing components that perform functions
described herein. Furthermore, various embodiments include
advertising and selling products that perform functions described
herein, that contain structure described herein, or that include
instructions to perform functions described herein, as examples.
Such products may be obtained or provided through distributors,
dealers, or over the Internet, for instance. The subject matter
described herein also includes various means for accomplishing the
various functions or acts described herein or apparent from the
structure and acts described.
* * * * *