U.S. patent application number 13/800322 was filed with the patent office on 2013-10-03 for energy efficiency of room air conditioner or unitary air conditioning system by using dual suction compressor.
This patent application is currently assigned to Whirlpool Corporation. The applicant listed for this patent is WHIRLPOOL CORPORATION. Invention is credited to Nihat Cur, Alberto Gomes, Steven Kuehl, Guolian Wu.
Application Number | 20130255309 13/800322 |
Document ID | / |
Family ID | 51625721 |
Filed Date | 2013-10-03 |
United States Patent
Application |
20130255309 |
Kind Code |
A1 |
Wu; Guolian ; et
al. |
October 3, 2013 |
ENERGY EFFICIENCY OF ROOM AIR CONDITIONER OR UNITARY AIR
CONDITIONING SYSTEM BY USING DUAL SUCTION COMPRESSOR
Abstract
A high-efficiency air conditioning system for chilling an
interior of a building that includes: a compressor; a condenser
having a condenser fan associated with the condenser that moves air
to cool the condenser; at least two evaporator sections wherein a
first evaporator section operates at a first evaporator pressure
and a second evaporator section operates at a second evaporator
pressure that is different than the first evaporator pressure; at
least a first throttling device and a second throttling device
having different throttling characteristics with the first
throttling device being less restrictive than the second throttling
device; and a plurality of refrigerant conduits.
Inventors: |
Wu; Guolian; (St. Joseph,
MI) ; Kuehl; Steven; (Stevensville, MI) ;
Gomes; Alberto; (St. Joseph, MI) ; Cur; Nihat;
(St. Joseph, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
WHIRLPOOL CORPORATION |
Benton Harbor |
MI |
US |
|
|
Assignee: |
Whirlpool Corporation
Benton Harbor
MI
|
Family ID: |
51625721 |
Appl. No.: |
13/800322 |
Filed: |
March 13, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61622840 |
Apr 11, 2012 |
|
|
|
61618914 |
Apr 2, 2012 |
|
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Current U.S.
Class: |
62/510 ;
62/498 |
Current CPC
Class: |
F25B 49/02 20130101;
F25B 5/02 20130101; F25B 7/00 20130101; F25B 1/10 20130101; F25B
5/00 20130101; F25B 39/028 20130101; F24F 3/1405 20130101; F25B
41/043 20130101; F25B 1/00 20130101 |
Class at
Publication: |
62/510 ;
62/498 |
International
Class: |
F25B 5/00 20060101
F25B005/00 |
Claims
1. A high-efficiency air conditioning system for chilling an
interior of a building comprising: a compressor; a condenser having
a condenser fan associated with the condenser that moves air to
cool the condenser; at least two evaporator sections wherein a
first evaporator section operates at a first evaporator pressure
and a second evaporator section operates at a second evaporator
pressure that is different than the first evaporator pressure; at
least a first throttling device and a second throttling device
having different throttling characteristics with the first
throttling device being less restrictive than the second throttling
device; and a plurality of refrigerant conduits; and wherein a
refrigerant fluid leaves the compressor along a common refrigerant
flow-path portion of a refrigerant circuit from the compressor,
through the condenser and into the first and second throttling
devices which split the common flow-path portion of the refrigerant
circuit and deliver refrigerant fluid to a first evaporator and to
a second evaporator forming a first evaporator circuit portion and
a second evaporator circuit portion of the refrigerant circuit and
wherein the first evaporator circuit portion operates at a higher
temperature than the second evaporator circuit portion and wherein
the first evaporator circuit portion and the second evaporator
circuit portion merge and rejoin the common refrigerant flow-path
portion.
2. The high-efficiency air conditioning system of claim 1, wherein
the compressor is a dual suction compressor and the first
evaporator section and the second evaporator section are each
separate evaporators.
3. The high-efficiency air conditioning system of claim 2, wherein
the first evaporator circuit portion delivers refrigerant to the
dual suction compressor via a first intake port of the dual suction
compressor and the second evaporator circuit portion delivers
refrigerant to the dual suction compressor via a second intake port
of the dual suction compressor and the dual suction compressor
delivers a refrigerant to the common refrigerant flow-path.
4. The high-efficiency air conditioning system of claim 2, wherein
the first and second throttling devices are each a capillary
tube.
5. The high-efficiency air conditioning system of claim 2, wherein
at least two of the evaporator sections share a common evaporator
fm that provides reduced conductive thermal communication between
adjacent sections compared to a single continuous non-interrupted
fin evaporator.
6. The high-efficiency air conditioning system of claim 1, wherein
the first evaporator section proceeds the second evaporator section
and are in the same air flow supply path that supplies chilled air
to one or more living areas within a building.
7. The high-efficiency air conditioning system of claim 2, wherein
the first evaporator section proceeds the second evaporator section
and are in the same air flow supply path that supplies chilled air
to one or more living areas within a building.
8. The high-efficiency air conditioning system of claim 1, wherein
the first evaporator section operates to remove more latent heat
than the second evaporator section and the second evaporator
section removes more sensible heat than the first evaporator
section.
9. The high-efficiency air conditioning system of claim 1, wherein
the first evaporator circuit portion and the second evaporator
circuit portion merge and rejoin the common refrigerant flow-path
portion within the compressor.
10. The high-efficiency air conditioning system of claim 1 further
comprising a three-way valve having two refrigerant intakes and a
single refrigerant outlet that delivers refrigerant fluid to the
evaporator wherein the intakes individually receive refrigerant
fluid from the first evaporator circuit portion and the second
evaporator circuit portion after the refrigerant fluid has passed
through the first evaporator section and the second evaporator
section.
11. The high-efficiency air conditioning system of claim 10,
wherein the first evaporator section and the second evaporator
section are in the same air flow supply path that supplies chilled
air to one or more living areas within a building.
12. The high-efficiency air conditioning system of claim 1, wherein
the first evaporator section is positioned within a primary air
cooling path that delivers chilled air to the interior of the
building and the second evaporator section is positioned between an
outside air port of the building and the primary air cooling path
such that the second evaporator section chills air received into
the interior of the building from outside the building.
13. The high-efficiency air conditioning system of claim 2, wherein
the first evaporator section is positioned within a primary air
cooling path that delivers chilled air to the interior of the
building and the second evaporator section is positioned between an
outside air port of the building and the primary air cooling path
such that the second evaporator section chills air received into
the interior of the building from outside the building.
14. The high-efficiency air conditioning system of claim 10,
wherein the first evaporator section is positioned within a primary
air cooling path that delivers chilled air to the interior of the
building and the second evaporator section is positioned between an
outside air port of the building and the primary air cooling path
such that the second evaporator section chills air received into
the interior of the building from outside the building.
15. The high-efficiency air conditioning system of claim 10,
wherein the first evaporator section and the second evaporator
section are in the same air flow supply path that supplies chilled
air to one or more building areas within a building and the
throttling devices are each capillary tubes.
16. The high-efficiency air conditioning system of claim 1, wherein
the high efficiency air conditioning system is a forced air
conditioning system and the high efficiency air conditioning system
further comprises a supply fan that circulates air past at least
the first evaporator section and circulates air to and from the one
or more building areas within a building.
17. The high-efficiency air conditioning system of claim 16,
wherein the compressor and condenser are positioned outside of the
building and the first evaporator section and the second evaporator
section and the supply fan are all positioned within the
building.
18. The high-efficiency air conditioning system of claim 2, wherein
the compressor and condenser are both positioned outside of the
building.
19. The high-efficiency air conditioning system of claim 10,
wherein the compressor and condenser section are both positioned
outside of the building.
20. A high-efficiency air conditioning system for chilling an
interior of a building comprising: a dual-suction compressor; a
condenser having a condenser fan associated with the condenser that
moves air to cool the condenser; at least two evaporators wherein a
first evaporator operates at a first evaporator pressure and a
second evaporator operates at a second evaporator pressure that is
different than the first evaporator pressure; at least a first
throttling device and a second throttling device having different
throttling characteristics with the first throttling device being
less restrictive than the second throttling device; and a plurality
of refrigerant conduits; and wherein a refrigerant fluid leaves the
compressor along a common refrigerant flow-path portion of a
refrigerant circuit from the compressor, through the condenser and
into the first and second throttling devices which split the common
flow-path portion of the refrigerant circuit and deliver
refrigerant fluid to the first evaporator and to the second
evaporator forming a first evaporator circuit portion and a second
evaporator circuit portion of the refrigerant circuit and wherein
the first evaporator circuit portion operates at a higher
temperature than the second evaporator circuit portion and wherein
the first evaporator circuit portion delivers to refrigerant fluid
to a first suction port of the dual suction compressor and the
second evaporator circuit portion delivers refrigerant fluid to a
second suction port of the dual suction compressor and the first
evaporator circuit portion and the second evaporator circuit
portion merge and rejoin the refrigerant fluid into the common
refrigerant flow-path portion; and wherein the compressor,
condenser are all positioned outside of the building and the first
evaporator and the second evaporator are positioned within the
building.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claim priority to and the benefit of U.S.
Provisional Patent Application Ser. No. 61/622,840, filed on Apr.
11, 2012, entitled LOW ENERGY AIR CONDITIONING WITH TRUE COMFORT
CONTROL, the entire disclosure of which is hereby incorporated by
reference.
BACKGROUND
[0002] Air conditioning systems for building structures, dwellings
or individual rooms have historically utilized a standard vapor
compression cooling system to cool an interior volume of a building
structure 2 containing walls 4 and/or ceilings 6. A traditional
home or building air conditioning system is shown schematically in
FIG. 1. As shown there, the air conditioning system 10 typically
includes an exterior positioned machine compartment housing 12
mounted on a base platform 14 where the housing 12 contains a
single outlet, single input compressor 16, a condenser 18, and a
thermal expansion device 20. These traditional systems also
typically include a fan 22 associated with condenser 18, the size
of which depends on various factors. For whole dwelling/building
systems, which the compressor and condenser must provide higher
cooling capacity, the systems are sized to match thermal load and
are typically larger. Coolant fluid conduits 24 deliver coolant
through the vapor compression system and deliver coolant fluid that
has passed through the compressor, the condenser and the throttling
device to a single evaporator 26 that operates at a single
evaporator pressure located within an air passageway 28 within the
building structure 2. The air passageway could be an air duct, air
vents of a room air conditioning system or a portion of the
building's interior heating, ventilation and air conditioning
machine compartment located within the building structure 2.
Typically, the evaporator 26 is positioned within the building's
heating ventilation and air conditioning machine compartment. The
air passageway 28 typically has an air circulation fan 30
associated with it to distribute air through the building structure
2 or into a portion of the building structure. The air circulation
fan delivers air across the single evaporator where it is cooled
and the cooled air 32 distributed to the volume of interior air to
be cooled. Air is returned to the evaporator as shown by reference
numeral 34. Typically, a building structure may have an exterior
air inlet/path that allows exterior air to enter, typically
passively enter, the building structure from outside the building
structure either directly into the air passageway 28 or into the
building structure air where the exterior air is then circulated
within the building structure.
[0003] While this system does cool the building structure interior
it typically does not allow for regulation of both the temperature
and humidity of the interior of a building structure. When this
traditional air conditioner is used, humidity is removed based upon
the temperature of the single evaporator. A person within the
interior volume of the building structure might want more or less
humidity removed from the air within the building structure than
what is allowed by such single evaporator systems.
BRIEF SUMMARY OF THE INVENTION
[0004] A high-efficiency air conditioning system for chilling an
interior of a building that includes: a compressor; a condenser
having a condenser fan associated with the condenser that moves air
to cool the condenser; at least two evaporator sections wherein a
first evaporator section operates at a first evaporator pressure
and a second evaporator section operates at a second evaporator
pressure that is different than the first evaporator pressure; at
least a first throttling device and a second throttling device
having different throttling characteristics with the first
throttling device being less restrictive than the second throttling
device; and a plurality of refrigerant conduits. The refrigerant
fluid leaves the compressor along a common refrigerant flow-path
portion of a refrigerant circuit from the compressor, through the
condenser and into the first and second throttling devices which
split the common flow-path portion of the refrigerant circuit and
deliver refrigerant fluid to a first evaporator and to a second
evaporator forming a first evaporator circuit portion and a second
evaporator circuit portion of the refrigerant circuit. The first
evaporator circuit portion operates at a higher temperature than
the second evaporator circuit portion and the first evaporator
circuit portion and the second evaporator circuit portion merge and
rejoin the common refrigerant flow-path portion.
[0005] A high-efficiency air conditioning system for chilling an
interior of a building that includes a dual-suction compressor; a
condenser having a condenser fan associated with the condenser that
moves air to cool the condenser; at least two evaporators wherein a
first evaporator operates at a first evaporator pressure and a
second evaporator operates at a second evaporator pressure that is
different than the first evaporator pressure; at least a first
throttling device and a second throttling device having different
throttling characteristics with the first throttling device being
less restrictive than the second throttling device; and a plurality
of refrigerant conduits. A refrigerant fluid leaves the compressor
along a common refrigerant flow-path portion of a refrigerant
circuit from the compressor, passes through the condenser and into
the first and second throttling devices which split the common
flow-path portion of the refrigerant circuit and deliver
refrigerant fluid to the first evaporator and to the second
evaporator forming a first evaporator circuit portion and a second
evaporator circuit portion of the refrigerant circuit. The first
evaporator circuit portion operates at a higher temperature than
the second evaporator circuit portion and wherein the first
evaporator circuit portion delivers to refrigerant fluid to a first
suction port of the dual suction compressor and the second
evaporator circuit portion delivers refrigerant fluid to a second
suction port of the dual suction compressor and the first
evaporator circuit portion and the second evaporator circuit
portion merge and rejoin the refrigerant fluid into the common
refrigerant flow-path portion. The compressor and condenser are
positioned outside of the building and the first evaporator and the
second evaporator are positioned within the building.
[0006] These and other features, advantages, and objects of the
present invention will be further understood and appreciated by
those skilled in the art by reference to the following
specification, claims, and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The foregoing summary, as well as the following detailed
description of the invention, will be better understood when read
in conjunction with the appended drawings. For the purpose of
illustrating the invention, there are shown in the drawings,
certain embodiment(s) which are presently preferred. It should be
understood, however, that the invention is not limited to the
precise arrangements and instrumentalities shown. Drawings are not
necessarily to scale, but relative special relationships are shown
and the drawings may be to scale especially where indicated. As
such, in the description or as would be apparent to those skilled
in the art certain features of the invention may be exaggerated in
scale or shown in schematic form in the interest of clarity and
conciseness.
[0008] FIG. 1 is a schematic view of traditional air conditioning
system employing a single evaporator operating at a single
evaporating pressure and a single inlet and single outlet
compressor;
[0009] FIG. 2 is a schematic view of an air conditioning system for
a building structure according to an aspect of the present
invention employing a dual suction compressor and two evaporators
operating at two different evaporating temperatures;
[0010] FIG. 3 is a schematic view of an air conditioning system for
a building structure according to an aspect of the present
invention employing a dual suction compressor and two evaporators
operating at two different evaporating temperatures with one
evaporator treating air taken in from the outdoor air and
thereafter into the air passageway of the air conditioning
system;
[0011] FIG. 4a is a thermodynamic cycle of a dual suction and dual
discharge compressor containing air treatment system that may be
utilized in connection methods of improving efficiency of the air
conditioning system according to an aspect of the present
invention;
[0012] FIG. 4b is a thermodynamic cycle of a dual discharge
compressor containing air treatment system that may be utilized in
connection methods of improving efficiency of the air conditioning
system according to an aspect of the present invention;
[0013] FIG. 5 shows a compressor according to an aspect of the
present invention showing dual suction;
[0014] FIG. 6 shows another embodiment of a single suction
compressor employing a three-way valve either inside the compressor
or outside the compressor housing (the housing shown by the dashed
line) according to an aspect of the present invention enabling dual
suction;
[0015] FIG. 7 shows another embodiment of a compressor employing
two solenoid valves on either inside the compressor or outside the
compressor housing (the housing shown by the dashed line) according
to an aspect on the present invention showing dual suction;
[0016] FIG. 8a is a schematic view of a dual suction-dual discharge
compressor;
[0017] FIG. 8b is a schematic view of a single discharge compressor
with a dual discharging switching mechanism;
[0018] FIG. 9 is a schematic view of a dual discharge compressor
containing air conditioning system of the type described in the
thermodynamic cycle of FIG. 4b according to an aspect of the
present invention;
[0019] FIG. 10 is a schematic view of a dual suction and dual
discharge compressor containing air conditioning system of the type
described in the thermodynamic cycle of FIG. 4a according to an
aspect of the present invention;
[0020] FIG. 11a is a top schematic view of an evaporator system
according to an aspect of the present invention employing
evaporator coils operating at different temperatures and
interconnected with common fins;
[0021] FIG. 11b is an elevated schematic side view of the
evaporator of FIG. 11a;
[0022] FIG. 12a is a top schematic view of an evaporator system
according to an aspect of the present invention employing
evaporator coils operating at different temperatures that are
disconnected by having fins of one evaporator constructed and
aligned to feed airflow into the fins of the lower temperature
evaporator;
[0023] FIG. 12b is an elevated schematic side view of the
evaporator of FIG. 12a;
[0024] FIG. 13 is a schematic view of another aspect of the present
invention showing a retrofitted air conditioning thermal storage
system;
[0025] FIG. 14 is a schematic view of another aspect of the present
invention showing a retrofitted air conditioning thermal storage
system;
[0026] FIG. 15 is a schematic view of a split air conditioning
system according to another aspect of the present invention;
and
[0027] FIG. 16 is another schematic view of a single outdoor air
conditioning system according to another aspect of the present
invention.
DETAILED DESCRIPTION
[0028] Before the subject invention is described further, it is to
be understood that the invention is not limited to the particular
embodiments of the invention described below, as variations of the
particular embodiments may be made and still fall within the scope
of the appended claims. It is also to be understood that the
terminology employed is for the purpose of describing particular
embodiments, and is not intended to be limiting. Instead, the scope
of the present invention will be established by the appended
claims.
[0029] Where a range of values is provided, it is understood that
each intervening value, to the tenth of the unit of the lower limit
unless the context clearly dictates otherwise, between the upper
and lower limit of that range, and any other stated or intervening
value in that stated range, is encompassed within the invention.
The upper and lower limits of these smaller ranges may
independently be included in the smaller ranges, and are also
encompassed within the invention, subject to any specifically
excluded limit in the stated range. Where the stated range includes
one or both of the limits, ranges excluding either or both of those
included limits are also included in the invention.
[0030] In this specification and the appended claims, the singular
forms "a," "an" and "the" include plural reference unless the
context clearly dictates otherwise.
[0031] The present invention is generally directed toward improved,
more efficient air conditioning systems 110 for building structures
2. The air conditioning systems 110 relate to building structure
air conditioning systems 110 that treat the air within all or a
portion of the interior of a building structure. The systems
discussed herein may be employed as whole building treatment
systems, one room air conditioning systems, such as often employed
by hotels, and all systems sized in-between. Conceivably, the
systems could be used to treat only a portion of a single room.
Essentially, the systems may be scaled as desired to work to treat
whatever volume of internal space within a building structure as
may be desired.
[0032] As shown in FIG. 2, air conditioning systems 110 according
to various aspects of the present invention for building structures
or individual rooms utilize a vapor compression cooling system to
cool an interior volume of a building structure 2 that employs a
dual suction compressor 116 (FIG. 2), a dual suction-dual discharge
compressor 117 (FIG. 10) or a dual discharge compressor 119 (FIG.
9). As shown in FIG. 2, the air conditioning system 110 typically
includes an exterior positioned machine compartment housing 112
mounted on a base platform 114 where the housing 112 contains a
dual suction compressor 116, a condenser 118, and a number of
thermal expansion device 120 that typically matches the number of
evaporators of the system. The air conditioning systems 110 of the
present invention also typically include one or more fan 122
associated with condenser 118, the size and number of which depends
on various factors. For whole building (home) systems that require
more cooling capacity, the compressor and condenser must provide
the higher cooling capacity, the fan(s) are larger and/or move air
at a faster rate to cool the condenser adequately.
[0033] Coolant fluid conduits 124 deliver coolant through the vapor
compression system and deliver coolant fluid that has passed
through the compressor 116, the condenser 118 and the throttling
device 120 to a plurality of evaporators 126, 127 (two are shown,
but more than two could conceivably be employed and even greater
efficiencies obtained) that operate within an air passageway 128
within the building structure 2. The air passageway could be an air
duct, air vents of a room air conditioning system or a portion of
the building's interior heating, ventilation and air conditioning
machine compartment located within the building structure 2.
Typically, the evaporators 126 and 127 are positioned proximate the
building's heating ventilation and air conditioning machine
compartment or within a portion of it. The air passageway 128
typically has an air circulation fan 130 associated with it to
distribute air through the building structure 2 or into a portion
of the building structure when the air conditioning system 110
treats a single room or an area smaller than an entire interior
volume of a building structure. The air circulation fan delivers
air across the evaporators 126, 127 where the air is cooled at two
different evaporator temperatures and the cooled air 132 is
distributed to the volume of interior air to be cooled within the
building structure. Air is returned to the evaporator as shown by
reference numeral 134. Typically, a building structure may have an
exterior air inlet/path that allows exterior air to enter,
typically passively enter, the building structure from outside the
building structure either directly into the air passageway 128 or
into the building structure air where the exterior air is then
circulated within the building structure.
[0034] FIG. 3 shows a similar system to FIG. 2; however, the
evaporator 126, which is the higher temperature evaporator as
discussed more herein, conditions air from outside and allows for
greater quantities of external (fresh) air to enter the building
structure thereby improving the air quality of the air inside the
building structure such as a home. As discussed in the
Environmental Protection Agency's publication entitled "The Inside
Story: A Guide to Indoor Air Quality," outdoor air enters and
leaves a house by: infiltration, natural ventilation, and
mechanical ventilation. Infiltration describes outdoor air flows
into the house through openings, joints, and cracks in walls,
floors, and ceilings, and around windows and doors. Air moves
through natural ventilation through opened windows and doors.
Infiltration and natural ventilation is primarily caused by air
temperature differences between indoors and outdoors and by wind. A
number of mechanical ventilation devices exist to allow more
outdoor air inside such as outdoor-vented fans that intermittently
remove air from a single room, such as bathrooms and kitchens, and
air handling systems that use fans and duct work to continuously
remove indoor air and distribute filtered and conditioned outdoor
air to strategic points throughout the house. The rate at which
outdoor air replaces indoor air is the air exchange rate. When
there is little infiltration, natural ventilation, or mechanical
ventilation, the air exchange rate is low and indoor pollutant
levels can increase. The present invention significantly increases
the air exchange rate when the system of FIG. 3 is employed
allowing for direct intake of outdoor air into the air conditioning
system. Typically, the intake is fluidly coupled to, more typically
proximate, a suction side of an air moving device such as a fan.
For example, as shown in FIG. 3, the intake is fluidly coupled and
proximate the air circulation fan 130, which draws.
[0035] The air conditioning system allows for the pretreatment of
the outdoor air by the higher temperature evaporator 126. The
higher temperature evaporator 126 is typically positioned just
inside the building structure proximate one or more vents 138,
which can be automatically or manually opened or closed. Instead of
venting, louvers or other air closing mechanisms might be employed
instead or in addition to the venting. In this manner the air
conditioning system regulates and controls the volume of fresh,
exterior air supplied to the system and thereby to the interior of
the building structure. The addition of more fresh, exterior air
from outside the building structure helps improve indoor air
quality. The system is typically designed to strike a balance
between the amount of fresh air and the energy efficiency. Due to
the increased energy efficiency of the present invention, for the
same amount of energy, the system can introduce fresh air from
outside the building structure and therefore improve indoor air
quality. Alternatively, energy efficiency may be further enhanced
with less fresh, exterior air supplied to the system.
[0036] In the context of the present invention, a control unit 140
may be in signal communication with each of the components of the
air conditioning systems of the present invention to dynamically
adjust various elements of the system, including the compressor
cooling capacity, to maximize energy efficiency. The control unit
140 may optionally receive one or more signals or other input from
a user input such as the desired temperature for a given building
structure interior volume or, for example, temperature sensors
within a building structure or input from the compressor regarding
the cooling capacity being supplied by the compressor. The control
unit 140, which might be a computer system or processor such as a
microprocessor, for example, is typically configured to dynamically
adjust the functions of the various types (dual suction, dual
suction-dual discharge, and dual discharge) compressors of the
present invention, including, in the case of FIGS. 2-3, the
functioning of the switching mechanism of the dual suction
compressor, based upon one or more or all of these inputs to create
the most efficient system possible. The control unit 140 also may
control the one or more vents 138 between an open and closed
position and any position there between and may also regulate the
total cooling capacity being supplied by the compressor when the
compressor is a variable capacity compressor such as a linear
compressor or an oil-less, orientation flexible linear compressor.
However, the application more likely will utilize a reciprocating
compressor or a scroll compressor, which can be either single or
variable capacity. It is also possible to further improve the
efficiency of the system by also regulating and varying
appropriately the fan(s) and/or compressor cooling capacity
modulation through, for example, compressor speed or stroke length
in the case of a linear compressor.
[0037] The present invention includes the use of multiple (dual)
evaporator systems that employ a switching mechanism for return of
coolant to the compressor. The switching mechanism allows the
system to better match total thermal loads with the cooling
capacities provided by the compressor. Generally speaking, the
system gains efficiency by employing the switching mechanism, which
allows rapid suction port switching, typically on the order of a
fraction of a second. The switching mechanism can be switched at a
fast pace, typically about 30 seconds or less or exactly 30 seconds
or less, more typically about 0.5 seconds or less or exactly 0.5
seconds or less, and most typically about 10 milliseconds or less
or exactly 10 milliseconds or less (or any time interval from about
30 seconds or less). As a result, the system rapidly switches
between a lower temperature evaporator 127 cooling operation mode
and a higher temperature evaporator 126 cooling operation mode. The
compressor 112 may be a variable capacity compressor, such as a
linear compressor, in particular an oil-less linear compressor,
which is an orientation flexible compressor (i.e., it operates in
any orientation not just a standard upright position, but also a
vertical position and an inverted position, for example). The
compressor is typically a dual suction compressor (See FIG. 5) or a
single suction compressor (See FIGS. 6-7) with an external
switching mechanism. When the compressor is a single suction
compressor (FIG. 6-7), it typically provides non-simultaneous dual
suction from the coolant fluid conduits 144 from the higher
temperature air treatment evaporator and the lower temperature air
treatment evaporator
[0038] As shown in FIGS. 2-3, one aspect of the present invention
utilizes a sequential, dual evaporator refrigeration system as the
air conditioning system 110. The dual evaporator refrigeration
system shown in FIG. 2 employs a lower temperature evaporator 127
and a higher temperature evaporator 126 are each fed by coolant
fluid conduits 124 engaged to two separate expansion devices 120.
Due to the evaporating pressure differences cooling the air at
different operating temperatures, the evaporators do not
continuously feed refrigerant flow to the suction lines
simultaneously and thus are activated as cooling is needed at
different levels and to regulate the humidity of the air. In this
sense, a major advantage of the dual (or multiple) evaporator
system is that the higher temperature evaporator runs at a higher
temperature than the lower temperature evaporator, thereby
increasing the overall coefficient of performance (See FIG. 4a for
a dual suction/dual discharge compressor and FIG. 4b for dual
discharge compressor).
[0039] Because the higher temperature evaporator coolant circuit
operates at a much higher temperature than the lower temperature
evaporator coolant circuit operates, the thermodynamic efficiency
of the cooling system is improved. For example, assuming that the
evaporating temperature is 7.2.degree. C. and the condensing
temperature is 54.4.degree. C. and the isentropic efficiency
(including motor efficiency) is 0.6, the COP of the cooling system
would be estimated at 2.69. In a dual suction compressor system,
assuming the coolant circuits are 50% and 50% in terms of heat
transfer area and assuming the first circuit operates at an
evaporating temperature of 17.degree. C., the first circuit COP is
3.66. The overall COP of the system employing a dual suction system
would be (0.5*3.66)+(2.69*0.5)=3.175. This amounts to about an 18%
improvement in system COP compared to the conventional single
suction compressor system. The analysis assumes that the condensing
temperature is the same for both circuits. In fact, the condensing
temperature will be higher for dual suction compressor system so
the actual COP will be lower than 18%, but significant COP are
achieved using such dual suction systems. The overall coefficient
of performance is a weighted average of the coefficient of
performance of the higher temperature evaporator containing circuit
and the lower temperature as follows:
COP.sub.Total==X*COP.sub.HTE+(1-X)*COP.sub.LTE
"X" is the ratio of high temperature evaporator cooling rate to the
total cooling rate the system provides.
[0040] As discussed above, the first evaporator may treat the
initial air either within the air passageway directly in line with
the second evaporator (FIG. 2) or it may be positioned to pre-cool
and dehumidify air received from outside the building structure
(FIG. 3). The lower temperature evaporator 127, which operates at a
lower pressure (colder temperature), may be used to pull more
moisture out of the air and thereby regulate humidity in an
interior volume of the building structure. Similarly, if the higher
temperature evaporator is used more to cool the interior air of the
building structure, the humidity level would be higher. There would
be less latent cooling and thus less moisture removed from the
air.
[0041] While the use of two evaporators is the typical
configuration of this embodiment of the present invention, the
configuration could conceivably utilize, three, four, or more
evaporators positioned at various outdoor air intakes or locations
within the air passageways. So long as the lower temperature
evaporator circuit is at a lower temperature than the higher
temperature evaporator circuit and the average temperature of the
two evaporators is warmer than the average temperatures of the air
passing through a single evaporator, efficiencies are gained.
[0042] An aspect of the present invention includes increasing the
efficiency of the air conditioning system by rapidly switching
between the lower temperature evaporator operation mode and a
higher temperature evaporator operation mode. Where T1 is the
opening time of the high pressure suction port; T2 is the opening
time of the low pressure suction port; T_on is the compressor on
time; and the T_off is the compressor off time, by varying T1, T2,
T_on and T_off, it is possible to most efficiently meet the total
thermal load requirements of the building structure interior volume
being cooled with the cooling capacity (fixed or variable) provided
by the compressor to thereby increase the overall coefficient of
performance of the coolant system of the air conditioning system.
It is also possible to further improve the efficiency of the system
by also regulating and varying appropriately the fan(s) and/or
compressor cooling capacity modulation through, for example,
compressor speed or stroke length in the case of a linear
compressor.
[0043] The compressor 116 may be a standard reciprocating or rotary
compressor, a variable capacity compressor, including but not
limited to a linear compressor, or a multiple intake compressor
system (see FIGS. 5-7). When a standard reciprocating or rotary
compressor with a single suction port is used the system further
includes a switching mechanism 150 containing compressor system
(see FIG. 6-7). As shown in FIG. 5, a dual suction compressor 116
according to an aspect of the present invention may utilize a
valving system 142 incorporated into the compressor that contains
two coolant fluid intake streams 144, one from the lower
temperature evaporator and one from the higher temperature
evaporator. When a linear compressor, which can be on oil-less
linear compressor, is utilized, the linear compressor has a
variable capacity modulation, which is typically larger than a 3 to
1 modulation capacity typical with a variable capacity
reciprocating compressor. The modulation low end is limited by
lubrication and modulation scheme.
[0044] FIGS. 6-7 generally show a switching mechanism 150 according
to the present invention. FIG. 5, as discussed above, shows a
valving system 142 that is used in dual suction port compressor
systems. FIGS. 6 and 7 show a switching mechanism 150 that can be
positioned either external or within a single suction port system
that allows for two or more fluid intake conduits 144 to feed into
the single suction port. A compressor piston 146 is utilized in
each dual coolant fluid intake systems shown in FIGS. 5-7. In the
case of FIG. 5, coolant fluid is received into the piston chamber
148 from the lower temperature evaporator and higher temperature
evaporator fluid conduits when the piston 146 is drawn backward,
the piston chamber intake valves 152 are both opened, or, when the
solenoid switch 154 is activated, only coolant fluid from the lower
temperature evaporator fluid conduit is drawn in, and the piston
chamber intake valve 152 associated with the intake from the higher
temperature evaporator fluid conduit is not actuated, but retained
in a closed position. When the piston stroke is actuated toward the
piston chamber valves, piston chamber outlet valve 156 is opened by
fluid pressure to allow coolant fluid to pass to the condenser
118.
[0045] Alternatively, depending on which circuit will be open more
frequently, when the higher temperature evaporator circuit is
opened less frequently such as will typically be the case in the
case of the system of FIG. 3, the valve 152 to the higher
temperature evaporator circuit might be biased, typically by a
spring, to a normally closed position and the solenoid would bias
the valve to the open position when cooling is requested by the
system. In this manner still further energy is saved. Additionally,
the solenoid valve could be of the latching type that requires only
a pulse (typically on the order of 100-1500 milliseconds) of energy
to actuate.
[0046] An alternative embodiment is shown in FIGS. 6-7, which show
a single piston chamber intake valve 152, which is fed from a
switching mechanism 150. The switching system 150 as shown by lines
158 and 160, which represent the housing of the compressor, may be
within the housing of the compressor when the housing is at
position 158 relative to the switching mechanism 150 and outside of
the housing when the housing is in position 160 relative to the
switching mechanism 150. The position of the housing (represented
by reference numerals 158 and 160) in FIGS. 6 and 7 are simply
meant to display that the switching mechanism 150 may be outside of
the housing or within the housing of the single suction compressor.
The switching mechanism 150 may employ a magnetically actuated
solenoid system where obstruction 162 is actuated between a first
position (shown in FIG. 6) allowing refrigerant coolant to flow
from the (higher pressure/temperature) evaporator and a second
position (not shown) where the obstruction 162 is positioned to
block fluid paths from the higher pressure/temperature evaporator
and allow refrigerant to flow from the (lower pressure/temperature)
evaporator. The alternative embodiment shown in FIG. 7 shows two
solenoid valves 164 that may be controlled by the control unit 140
to be in an open or closed position. The solenoid valves 164
alternate coolant flows to the compressor between coolant from the
first fluid conduit and the second fluid conduit. The solenoid
valves are typically only opened one at a time. In the embodiments
of FIGS. 5-7 of the compressor systems, the pressure of the coolant
fluid leaving the compressor for the condenser is significantly
higher than the pressure of the coolant received from the higher
temperature evaporator or the lower temperature evaporator, but the
pressure of the coolant received from the higher temperature
evaporator fluid conduit is greater than the coolant received from
the lower temperature evaporator fluid conduit. This, as discussed
above, allows for greater efficiencies of the overall coolant
system.
[0047] As shown in FIGS. 9 and 10, still further efficiencies can
be gained on the air conditioning systems by using a multi/dual
discharge compressor that is either a single suction (see FIG. 9)
or a multi (dual-) suction compressor (see FIG. 10). In the case of
dual discharge compressors, the dual discharge coolant fluid
conduits typically independently feed separate thermal expansion
devices 120', 120'' after passing through the condenser 118. The
refrigerant flows from the first circuit 166 of the condenser to
the evaporator 127 via a less restrictive thermal expansion device
120' and from the second circuit 168 of the condenser to the
evaporator 127 via a more restrictive thermal expansion device
120'' than the thermal expansion device 120'. The dual discharge
compressor 117, 119 rapidly switches between the two discharge
ports. The frequency of the switching and the duration of operation
of each port can be controlled by the control unit 140 to match the
heat load requirement of each circuit of the condenser. Since the
first circuit operates at a lower condensing temperature, the
thermodynamic efficiency of the cooling system is improved as shown
in FIG. 4b.
[0048] Similar systems as used in connection with the suction side
of the compressor may also be used in connection with the discharge
side of the compressor. The compressor may be a dual suction-dual
discharge compressor (FIG. 8a). As shown in FIG. 8a, the compressor
may include two intakes 144 and two outlet valves 156.
Alternatively, as shown in FIG. 8b, a switching mechanism may be
used on the discharge side of the compressor and positioned within
or outside the housing of the compressor. The switching mechanism
may use a magnetic actuated obstruction or, more typically one or
more solenoid valves 164 to regulate the outgoing flow of coolant
fluid to the compressor coils.
[0049] As shown in FIG. 10, the system using a dual discharge
compressor may be combined with the use of a dual suction aspect to
the compressor to provide the dynamic adjustability to make the
system as efficient as possible by taking advantage of the concepts
of dual suction efficiency discussed above and the concepts of dual
discharge and rapid switching also discussed above. Conceivably,
the compressor may have multiple suction ports and multiple
discharge ports. More than two of each could be employed to create
still further efficiencies and flexibility in humidity adjustment
as discussed herein.
[0050] The systems with dual discharge may use the staged condenser
coils to provide heating to a household appliance. For example, the
condensers might be thermally associated with a water heater or a
drying chamber.
[0051] FIGS. 11a, 11b, 12a, 12b show two embodiments that show a
thermally disjointed evaporator system with the lower temperature
and higher temperature evaporators working together to regulate
sensible and latent heat but where there is either a thermal break
(FIGS. 11a, 11b) or physical separation (FIGS. 12a, 12b) between
the lower temperature evaporator 127 and the higher temperature
evaporator 126.
[0052] FIGS. 11a and 11b show a disjointed evaporator system 200
that employs the lower temperature evaporator 127 and the higher
temperature evaporator 126 in a manner that they share common fins
202. The common fins have at least one and more typically a
plurality of thermal break portions 204 at a distance from the
evaporator tubes to elongate and interrupt the conductive heat flow
path. The lower temperature evaporator 127 and higher temperature
evaporator 126 have a plurality of conduit loops and are parallel
with one another. The evaporator coils generally define a first
temperature zone of the evaporator system and a second temperature
zone of the evaporator system. The zones are generally separated by
the thermal break portions 204 that are positioned generally down
the center of the evaporator system between the lower temperature
evaporator coil section and the higher temperature evaporator coil
section of the evaporator system, which are generally each a half
of the overall evaporator system.
[0053] FIGS. 12a, and 12b show an alternative disjointed evaporator
system that align and position fins 302 and fins 304 relative to
one another such that the spacing of the fins that are engaged with
the higher temperature evaporator 126 are spaced apart to
facilitate the shedding of the condensate off the fins for optimal
heat transfer. The spaced apart fins (less than 22 fins per inch,
more likely about 14 to about 18 fins per inch) are typically
designed to feed the air flow into the space between fins 304 that
are operably connected to the lower temperature evaporator, which
predominately regulates sensible cooling, but do some
dehumidification as well. This construction helps facilitate
condensate shedding and the transfer of latent heat and overall
heat transfer. The downstream fins 304 have greater fins per inch
of evaporator coil than the upstream fins to facilitate heat
transfer with the airflow through the fins, for example, the fins
might be present in an amount of greater than 22 fins per inch,
i.e. 25 fins per inch or more. The lower temperature evaporator 127
and fins 304 would be primarily responsible for mostly sensible
cooling and some latent cooling in the system. The higher
temperature evaporator 126 and fins 302 would be primarily
responsible for most of the latent heat cooling and some sensible
cooling. Both evaporators will regulate latent and sensible heat to
some degree. These evaporator systems would most typically be
employed when the lower temperature and higher temperature
evaporators are spaced proximate to one another such as in the
embodiment of the present invention depicted schematically in FIG.
2. Such configurations with greater spaced apart fins could be used
in other embodiments with the evaporators are not proximate one
another. For example, in the context of FIG. 3, the evaporator
system could be used and the evaporators would not be arranged
relative to one another and the airflow path to have the airflow
over the fins 302 feed between the fins 304, but the more compact
nature of the fins 304 would enhance the sensible heat energy
transfer and the more spaced fins 302 would facilitate the initial
latent heat energy transfer and subsequent condensate drainage.
[0054] FIGS. 13 and 14 show a retrofittable air conditioning system
thermal storage system 400. The retrofittable thermal storage
system by be employed with the air conditioning systems of the
present invention or traditional air conditioning systems. FIGS. 13
and 14 show the retrofittable thermal storage system 400 installed
in connection with a traditional air conditioning system such as
that shown in FIG. 1.
[0055] The retrofittable thermal storage system 400 is installed to
store thermal cooling capacity in an air conditioning system for
use during peak usage times when the building structure's main
cooling system is offline or its use curtailed or otherwise
minimized. A pump 402, which may be positioned before or after the
thermal energy storage fluid tank 404 along the coolant loop 416.
While shown schematically as pumping coolant fluid in a
counterclockwise direction, the directional flow from the pump 402
could be in either direction so long as coolant is in thermal
communication/contact the thermal energy storage fluid tank 404 and
into the airflow path to be cooled by the heat exchanger 406. In
the aspect of the invention shown in FIG. 13, a heat exchanger 412
is positioned in the thermal energy storage fluid tank 404 and
operably connected to the coolant fluid lines of the coolant loop
416. The thermal energy storage fluid tank 404 is cooled, typically
during off peak times, by a refrigeration. system employing a
traditional compressor 16, condenser 18, thermal expansion device
20, fan 22, and evaporator 26. The evaporator 26 of the
retrofittable thermal storage system 400 is spaced within or
otherwise in thermal communication with the thermal energy storage
material (fluid) 414 within the thermal energy thermal storage
fluid tank 404. In the embodiment show in FIG. 14, the heat
exchanger 412 is omitted and the thermal energy storage fluid
within the thermal energy thermal storage fluid tank 404 itself
operates at the heat exchanger/coolant fluid. Coolant fluid in this
instance is the thermal energy storage fluid and is received into
the tank through outlet 408 and returns to the coolant loop 416
through inlet 410.
[0056] As shown in FIG. 15, in another embodiment of the present
invention, a split air conditioning system 500 may be utilized to
drive a plurality of indoor air units 502. (FIG. 15 shows two
indoor air units but multiple indoor air units can be employed and
one or more air units may be positioned in various rooms within a
building structure.) Each individual indoor air unit 502 can be
turned on or off in a given space. The split indoor air
conditioning system 500, as shown in FIG. 15, utilizes the dual
suction (multi-suction) compressor concepts described herein to
provide greater benefits. Switching the suction valves to feed the
evaporators of the various air conditioning units in the interior
of the home equally or to provide warmer or cooler evaporator
temperatures for the respective rooms is possible using this
system. The warmer temperature evaporator would cool the air less
but still provide a level of dehumidification. The cooler
evaporator could be utilized to chill air more but also dry the air
more. The cooling capacity and, thus, the temperature of an
evaporator at which it functions is based upon the expansion device
but also the flow rate of refrigerant and the suction pressure the
evaporator sees from the compressor. If the indoor units are
identical with identical expansion device resistance, then the
multi-suction valve systems of the present invention can drive
either evaporator to a lower or higher pressure relative to the
other evaporator(s). Certain ways to accomplish this include:
managing the opening and closing of the compressor suction valve(s)
or adjusting the timing of valve opening and compressor piston or
vane stroke position to achieve the desired pressure level range.
In the example shown in FIG. 15, the upper section might be a
living room which is kept cool and dry and driven by a lower
temperature evaporator (50.degree. F.). This will provide more
cooling capacity (refrigerant flow at lower evaporator pressure) by
biasing the duty cycle of the suction port accordingly. The cycle
on/off for use of a variable capacity compressor and fan may be
utilized to slow the rate of cooling and achieve a slight rise in
temperature (55.degree. F.).
[0057] The lower section of FIG. 15 might be a bedroom that is kept
more cool and moist for optimum comfort (a higher temperature
evaporator of about 60.degree. F., for example). This system would
provide higher suction pressure and less cooling capacity by
biasing the duty cycle of the suction port accordingly.
[0058] The system shown in FIG. 16 shows a single outdoor unit
driving a single (potentially multiple) indoor unit(s) in a split
system air conditioner with dual (multi) suction and a two-section
coil evaporator. Switching the suction valving in this embodiment
provide more or less chilled air temperatures and more or less
humidity in a given conditioned living space. The warmer
temperature evaporator would cool the air less but still provide a
level of dehumidification. A cooler evaporator would chill the air
more but dry the air more. In combination, the air can be cooled
and dehumidified to the desired level at an increased effective
COP. The cooling capacity and the temperature an evaporator runs at
is a function of the expansion device restriction, but also the
flow rate of the refrigerant and the suction pressure of the
evaporator as discussed above. It is this dynamic in the
multi-suction systems of the present invention that enables the
functionality described above.
[0059] FIG. 15 shows the compressor, which is typically a
multi-suction compressor 516, a fan 518, a condenser 520, expansion
devices 522, evaporators 524, and cross-flow fans 526 all fluidly
connected by coolant fluid conduits 528. The evaporators 524 are
each individually spaced in separate building structure cooling
zones or rooms, 530 and 532 in FIG. 15. FIG. 16 shows a similar
system, but the two evaporators, as discussed above, are in the
same unit and used to condition the space within a single zone or
room of a structure 534.
[0060] Those skilled in the art will recognize, or be able to
ascertain using no more than routine experimentation, many
equivalents to the specific embodiments of the invention described
herein. Such equivalents are intended to be encompassed by the
following claims.
* * * * *