U.S. patent application number 16/335397 was filed with the patent office on 2019-10-03 for heat pump use apparatus.
This patent application is currently assigned to Mitsubishi Electric Corporation. The applicant listed for this patent is Mitsubishi Electric Corporation. Invention is credited to Taro HATTORI, Hirokazu MINAMISAKO, Kazutaka SUZUKI, Yasuhiro SUZUKI.
Application Number | 20190301750 16/335397 |
Document ID | / |
Family ID | 62626968 |
Filed Date | 2019-10-03 |
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United States Patent
Application |
20190301750 |
Kind Code |
A1 |
SUZUKI; Yasuhiro ; et
al. |
October 3, 2019 |
HEAT PUMP USE APPARATUS
Abstract
Provided is a heat pump use apparatus, including a refrigerant
circuit, a heat medium circuit, and a heat exchanger configured to
exchange heat between refrigerant and a heat medium. A main passage
of the heat medium circuit includes a branching portion and a
joining portion. A pressure protection device and a refrigerant
leakage detection device are connected to the main passage. The
pressure protection device is connected to the main passage at a
connecting portion located between the heat exchanger and one of
the branching portion and the joining portion. A first interruption
device configured to be able to interrupt a flow from the heat
exchanger to the connecting portion is provided in the main passage
at a portion between the heat exchanger and the connecting portion.
A second interruption device configured to be able to interrupt a
flow from the heat exchanger to an other of the branching portion
and the joining portion is provided in the main passage at a
portion between the heat exchanger and the other of the branching
portion and the joining portion.
Inventors: |
SUZUKI; Yasuhiro; (Tokyo,
JP) ; SUZUKI; Kazutaka; (Tokyo, JP) ;
MINAMISAKO; Hirokazu; (Tokyo, JP) ; HATTORI;
Taro; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Mitsubishi Electric Corporation |
Tokyo |
|
JP |
|
|
Assignee: |
Mitsubishi Electric
Corporation
Tokyo
JP
|
Family ID: |
62626968 |
Appl. No.: |
16/335397 |
Filed: |
December 21, 2016 |
PCT Filed: |
December 21, 2016 |
PCT NO: |
PCT/JP2016/088107 |
371 Date: |
March 21, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F24D 17/02 20130101;
F25B 2341/0662 20130101; F25B 2339/047 20130101; F25B 40/00
20130101; F25B 47/025 20130101; F24H 9/165 20130101; F25B 2500/222
20130101; F24H 9/2014 20130101; F24H 9/2021 20130101 |
International
Class: |
F24D 17/02 20060101
F24D017/02; F24H 9/16 20060101 F24H009/16; F24H 9/20 20060101
F24H009/20; F25B 47/02 20060101 F25B047/02; F25B 40/00 20060101
F25B040/00 |
Claims
1. A heat pump use apparatus, comprising: a refrigerant circuit
configured to circulate refrigerant; a heat medium circuit
configured to allow a heat medium to flow therethrough; and a heat
exchanger configured to exchange heat between the refrigerant and
the heat medium, the heat medium circuit including a main passage
extending through the heat exchanger, the main passage including a
branching portion to which a plurality of branch passages branched
from the main passage are connected, the branching portion being
provided at a downstream end of the main passage, and a joining
portion at which the plurality of branch passages are connected to
each other to be joined to the main passage, the joining portion
being provided at an upstream end of the main passage, the heat
pump use apparatus further comprising a pressure protection device
and a refrigerant leakage detection device that are connected to
the main passage, the pressure protection device being connected to
the main passage at a connecting portion located between the heat
exchanger and one of the branching portion and the joining portion,
the main passage including a first interruption device configured
to interrupt a flow from the heat exchanger to the connecting
portion, the first interruption device being provided between the
heat exchanger and the connecting portion, the main passage
including a second interruption device configured to interrupt a
flow from the heat exchanger to an other of the branching portion
and the joining portion, the second interruption device being
provided between the heat exchanger and the other of the branching
portion and the joining portion.
2. The heat pump use apparatus of claim 1, wherein each of the
first interruption device and the second interruption device
comprises an on-off valve which is closed when leakage of the
refrigerant into the heat medium circuit is detected.
3. The heat pump use apparatus of claim 1, wherein the refrigerant
leakage detection device is connected to the main passage at the
other of the branching portion and the joining portion, a portion
between the other of the branching portion and the joining portion
and the connecting portion, or the connecting portion.
4. The heat pump use apparatus of claim 1, wherein one interruption
device of the first interruption device and the second interruption
device, which is provided between the heat exchanger and the
joining portion, comprises a check valve, and wherein the
refrigerant leakage detection device is connected to the main
passage at a portion between the check valve and the connecting
portion or at the connecting portion.
5. The heat pump use apparatus of claim 1, wherein the refrigerant
leakage detection device is connected to the main passage at a
portion between the first interruption device and the second
interruption device.
6. The heat pump use apparatus of claim 1, wherein the refrigerant
leakage detection device is configured to detect the leakage of the
refrigerant into the heat medium circuit based on pressure in the
heat medium circuit.
7. The heat pump use apparatus of claim 1, further comprising: an
outdoor unit accommodating the refrigerant circuit, a part of the
heat medium circuit, and the heat exchanger; and an indoor unit
accommodating an other part of the heat medium circuit, wherein one
of the outdoor unit and the indoor unit accommodates the first
interruption device, the second interruption device, and the
refrigerant leakage detection device.
8. The heat pump use apparatus of claim 1, further comprising: an
outdoor unit accommodating a part of the refrigerant circuit; and
an indoor unit accommodating an other part of the refrigerant
circuit, the heat medium circuit, and the heat exchanger, wherein
the indoor unit accommodates the first interruption device, the
second interruption device, and the refrigerant leakage detection
device.
9. The heat pump use apparatus of claim 1, wherein the refrigerant
comprises flammable refrigerant or toxic refrigerant.
Description
TECHNICAL FIELD
[0001] The present invention relates to a heat pump use apparatus
including a refrigerant circuit and a heat medium circuit.
BACKGROUND ART
[0002] In Patent Literature 1, there is described an outdoor unit
for a heat pump cycle apparatus using flammable refrigerant. The
outdoor unit includes a refrigerant circuit including a compressor,
an air heat exchanger, an expansion device, and a water heat
exchanger, which are connected to one another through pipes, and a
pressure relief valve configured to prevent excessive rise of water
pressure in a water circuit configured to supply water heated in
the water heat exchanger. With this configuration, even when a
partition wall configured to partition the refrigerant circuit and
the water circuit is broken in the water heat exchanger so that the
flammable refrigerant is mixed into the water circuit, the
flammable refrigerant can be discharged to the outside through the
pressure relief valve.
CITATION LIST
Patent Literature
[0003] Patent Literature 1: Japanese Unexamined Patent Application
Publication No. 2013-167398
SUMMARY OF INVENTION
Technical Problem
[0004] In a heat pump use apparatus such as the heat pump cycle
apparatus, in general, a pressure relief valve of the water circuit
is provided in an indoor unit. There are various combinations of
the outdoor unit and the indoor unit in the heat pump use
apparatus. An outdoor unit and an indoor unit, which are
manufactured by the same manufacturer, may be combined. Further, an
outdoor unit and an indoor unit, which are manufactured by
different manufacturers, may be combined. Therefore, the outdoor
unit described in Patent Literature 1 may be combined with the
indoor unit including the pressure relief valve.
[0005] However, in Patent Literature 1, when the refrigerant is
leaked to the water circuit, the refrigerant mixed into water
inside the water circuit may be discharged not only through the
pressure relief valve provided in the outdoor unit, but also
through the pressure relief valve provided in the indoor unit.
Therefore, there is a problem in that the refrigerant may be leaked
to a room through the water circuit.
[0006] The present invention has been made to solve the problem
described above, and has an object to provide a heat pump use
apparatus capable of preventing leakage of refrigerant to a
room.
Solution to Problem
[0007] According to one embodiment of the present invention, there
is provided a heat pump use apparatus, including: a refrigerant
circuit configured to circulate refrigerant; a heat medium circuit
configured to allow a heat medium to flow therethrough; and a heat
exchanger configured to exchange heat between the refrigerant and
the heat medium. The heat medium circuit includes a main passage
extending through the heat exchanger. The main passage includes: a
branching portion to which a plurality of branch passages branched
from the main passage are connected, the branching portion being
provided at a downstream end of the main passage; and a joining
portion at which the plurality of branch passages are connected to
each other to be joined to the main passage, the joining portion
being provided at an upstream end of the main passage. The heat
pump use apparatus further includes a pressure protection device
and a refrigerant leakage detection device that are connected to
the main passage. The pressure protection device is connected to
the main passage at a connecting portion located between the heat
exchanger and one of the branching portion and the joining portion.
The main passage includes a first interruption device configured to
be able to interrupt a flow from the heat exchanger to the
connecting portion. The first interruption device is provided
between the heat exchanger and the connecting portion. The main
passage includes a second interruption device configured to be able
to interrupt a flow from the heat exchanger to an other of the
branching portion and the joining portion, The second interruption
device is provided between the heat exchanger and the other of the
branching portion and the joining portion.
Advantageous Effects of Invention
[0008] According to one embodiment of the present invention, even
when the refrigerant is leaked to the heat medium circuit, a flow
of the refrigerant mixed into the heat medium can be interrupted by
the interruption device. Therefore, the leakage of the refrigerant
from the pressure protection device to the room can be
prevented.
BRIEF DESCRIPTION OF DRAWINGS
[0009] [FIG. 1] FIG. 1 is a circuit diagram for illustrating a
schematic configuration of a heat pump use apparatus according to
Embodiment 1 of the present invention.
[0010] [FIG. 2] FIG. 2 is a circuit diagram for illustrating a
schematic configuration of a heat pump use apparatus of a
modification example of Embodiment 1 of the present invention.
[0011] [FIG. 3] FIG. 3 is an explanatory view for illustrating
examples of an arrangement position of a refrigerant leakage
detection device 98 in the heat pump use apparatus according to
Embodiment 1 of the present invention.
[0012] [FIG. 4] FIG. 4 is an explanatory view for illustrating the
example of the arrangement position of the refrigerant leakage
detection device 98 in the heat pump use apparatus according to
Embodiment 1 of the present invention.
[0013] [FIG. 5] FIG. 5 is an explanatory view for illustrating the
example of the arrangement position of the refrigerant leakage
detection device 98 in the heat pump use apparatus according to
Embodiment 1 of the present invention.
[0014] [FIG. 6] FIG. 6 is an explanatory view for illustrating the
example of the arrangement position of the refrigerant leakage
detection device 98 in the heat pump use apparatus according to
Embodiment 1 of the present invention.
[0015] [FIG. 7] FIG. 7 is a circuit diagram for illustrating a
schematic configuration of a heat pump use apparatus according to
Embodiment 2 of the present invention.
DESCRIPTION OF EMBODIMENTS
Embodiment 1
[0016] A heat pump use apparatus according to Embodiment 1 of the
present invention is described. FIG. 1 is a circuit diagram for
illustrating a schematic configuration of the heat pump use
apparatus according to Embodiment 1. In Embodiment 1, a heat pump
water heater 1000 is exemplified as the heat pump use apparatus. In
the drawings including FIG. 1 referred to below, a dimensional
relationship of components and a shape of each of the components
may be different from those of actual components.
[0017] As illustrated in FIG. 1, the heat pump water heater 1000
includes a refrigerant circuit 110 configured to circulate
refrigerant and a water circuit 210 configured to allow water to
flow therethrough. Further, the heat pump water heater 1000
includes an outdoor unit 100 installed outside, for example,
outdoor space, and an indoor unit 200 installed indoor space. The
indoor unit 200 is installed, for example, in a kitchen, a
bathroom, or a laundry room or, further, in a storage space such as
a closet inside a building.
[0018] The refrigerant circuit 110 includes a compressor 3, a
refrigerant flow switching device 4, a load-side heat exchanger 2,
a first pressure reducing device 6, an intermediate pressure
receiver 5, a second pressure reducing device 7, and a heat
source-side heat exchanger 1, which are annularly connected in
order through refrigerant pipes. Through use of the refrigerant
circuit 110, the heat pump water heater 1000 is capable of a normal
operation, for example, heater water heating operation, for heating
water flowing through the water circuit 210 and a defrosting
operation for circulating the refrigerant reversely to the normal
operation to defrost the heat source-side heat exchanger 1.
[0019] The compressor 3 is a fluid machine configured to compress
sucked low-pressure refrigerant and to discharge the low-pressure
refrigerant as high-pressure refrigerant. The compressor 3 of
Embodiment 1 includes an inverter device, and is configured to
change a driving frequency freely selectively, to thereby be able
to change a capacity, that is, an amount of the refrigerant to be
sent per unit time.
[0020] The refrigerant flow switching device 4 is configured to
switch a flow direction of the refrigerant inside the refrigerant
circuit 110 between the normal operation and the defrosting
operation. As the refrigerant flow switching device 4, for example,
a four-way valve is used.
[0021] The load-side heat exchanger 2 is a water-refrigerant heat
exchanger configured to exchange heat between the refrigerant
flowing through the refrigerant circuit 110 and the water flowing
through the water circuit 210. As the load-side heat exchanger 2,
for example, a plate heat exchanger is used. The load-side heat
exchanger 2 includes a refrigerant flow passage for allowing
refrigerant to flow therethrough as a part of the refrigerant
circuit 110, a water flow passage for allowing water to flow
therethrough as a part of the water circuit 210, and a thin
plate-like partition wall configured to partition the refrigerant
flow passage and the water flow passage. The load-side heat
exchanger 2 functions as a condenser (radiator) configured to heat
water during the normal operation, and functions as an evaporator
(heat absorber) during the defrosting operation.
[0022] The first pressure reducing device 6 is configured to
regulate a flow rate of refrigerant, for example, regulate a
pressure of the refrigerant flowing into the load-side heat
exchanger 2. The intermediate pressure receiver 5 is located
between the first pressure reducing device 6 and the second
pressure reducing device 7 in the refrigerant circuit 110, and is
configured to accumulate an excess of the refrigerant. A suction
pipe 11 connected to a suction side of the compressor 3 passes
through the inside of the intermediate pressure receiver 5. In the
intermediate pressure receiver 5, heat is exchanged between the
refrigerant passing through the suction pipe 11 and the refrigerant
inside the intermediate pressure receiver 5. Therefore, the
intermediate pressure receiver 5 has a function as an internal heat
exchanger for the refrigerant circuit 110. The second pressure
reducing device 7 is configured to regulate the pressure of the
refrigerant by regulating the flow rate of the refrigerant. The
first pressure reducing device 6 and the second pressure reducing
device 7 of Embodiment 1 are each an electronic expansion valve
capable of changing an opening degree based on an instruction from
a controller 101 described later.
[0023] The heat source-side heat exchanger 1 is an air-refrigerant
heat exchanger configured to exchange heat between the refrigerant
flowing through the refrigerant circuit 110 and outdoor air sent by
an outdoor air-sending fan or other devices (not shown). The heat
source-side heat exchanger 1 functions as an evaporator (heat
absorber) during the normal operation, and functions as a condenser
(radiator) during the defrosting operation.
[0024] Examples of refrigerants used as the refrigerants to be
circulated through the refrigerant circuit 110 include a slightly
flammable refrigerant such as R1234yf or R1234ze(E) and a strongly
flammable refrigerant such as R290 or R1270. Those refrigerants may
be each used as a single refrigerant, or may be used as a mixed
refrigerant obtained by mixing two or more kinds of the
refrigerants with each other. In the following description, the
refrigerant having flammability equal to or higher than a slightly
flammable level (for example, 2L or higher in category of ASHRAE34)
may be referred to as "refrigerant having flammability" or
"flammable refrigerant". Further, as the refrigerant to be
circulated through the refrigerant circuit 110, a nonflammable
refrigerant such as R4070 or R410A having nonflammability (for
example, 1 in the category of ASHRAE34) can be used. Those
refrigerants have a density larger than that of air under an
atmospheric pressure (for example, with a temperature being a room
temperature (25 degrees Celsius)). Further, as the refrigerant to
be circulated through the refrigerant circuit 110, a refrigerant
having toxicity such as R717 (ammonia) may also be used.
[0025] The outdoor unit 100 accommodates the refrigerant circuit
110 including the compressor 3, the refrigerant flow switching
device 4, the load-side heat exchanger 2, the first pressure
reducing device 6, the intermediate pressure receiver 5, the second
pressure reducing device 7, and the heat source-side heat exchanger
1.
[0026] Further, the outdoor unit 100 includes the controller 101
configured to mainly control an operation of the refrigerant
circuit 110, for example, the compressor 3, the refrigerant flow
switching device 4, the first pressure reducing device 6, the
second pressure reducing device 7, and the outdoor air-sending fan
(not shown). The controller 101 includes a microcomputer including
a CPU, a ROM, a RAM, and an I/O port. The controller 101 can
communicate with a controller 201 and an operation unit 202, which
are described later, through a control line 102.
[0027] Next, an example of the operation of the refrigerant circuit
110 is described. In FIG. 1, the flow direction of the refrigerant
in the refrigerant circuit 110 during the normal operation is
indicated by solid arrows. The refrigerant circuit 110 is
configured so that, during the normal operation, the refrigerant
flow passage is switched by the refrigerant flow switching device 4
as indicated by the solid arrows to cause the high-temperature and
high-pressure refrigerant to flow into the load-side heat exchanger
2.
[0028] The high-temperature and high-pressure gas refrigerant
discharged from the compressor 3 passes through the refrigerant
flow switching device 4, and flows into the refrigerant flow
passage of the load-side heat exchanger 2. During the normal
operation, the load-side heat exchanger 2 functions as a condenser.
That is, in the load-side heat exchanger 2, heat is exchanged
between the refrigerant flowing through the refrigerant flow
passage and the water flowing through the water flow passage of the
load-side heat exchanger 2, and the heat of condensation of the
refrigerant is transferred to the water. With this operation, the
refrigerant flowing through the refrigerant flow passage of the
load-side heat exchanger 2 is condensed to become a high-pressure
liquid refrigerant. Further, the water flowing through the water
flow passage of the load-side heat exchanger 2 is heated by
transfer heat from the refrigerant.
[0029] The high-pressure liquid refrigerant condensed by the
load-side heat exchanger 2 flows into the first pressure reducing
device 6, and has the pressure reduced slightly to become a
two-phase refrigerant. The two-phase refrigerant flows into the
intermediate pressure receiver 5, and is cooled by the heat
exchange with a low-pressure gas refrigerant flowing through the
suction pipe 11 to become a liquid refrigerant. The liquid
refrigerant flows into the second pressure reducing device 7, and
has the pressure reduced to become a low-pressure two-phase
refrigerant. The low-pressure two-phase refrigerant flows into the
heat source-side heat exchanger 1. During the normal operation, the
heat source-side heat exchanger 1 functions as an evaporator. That
is, in the heat source-side heat exchanger 1, heat is exchanged
between the refrigerant circulated through the inside and the
outdoor air sent by the outdoor air-sending fan, and the heat of
evaporation of the refrigerant is received from the outdoor air.
With this operation, the refrigerant that has flowed into the heat
source-side heat exchanger 1 evaporates to become the low-pressure
gas refrigerant. The low-pressure gas refrigerant passes through
the refrigerant flow switching device 4, and flows into the suction
pipe 11. The low-pressure gas refrigerant that has flowed into the
suction pipe 11 is heated by the heat exchange with the refrigerant
inside the intermediate pressure receiver 5, and is sucked by the
compressor 3. The refrigerant sucked by the compressor 3 is
compressed to become the high-temperature and high-pressure gas
refrigerant. In the normal operation, the above-mentioned cycle is
repeated.
[0030] Next, an example of the operation during the defrosting
operation is described. In FIG. 1, the flow direction of the
refrigerant in the refrigerant circuit 110 during the defrosting
operation is indicated by the broken arrows. The refrigerant
circuit 110 is configured so that, during the defrosting operation,
the refrigerant flow passage is switched by the refrigerant flow
switching device 4 as indicated by the broken arrows to cause the
high-temperature and high-pressure refrigerant to flow into the
heat source-side heat exchanger 1.
[0031] The high-temperature and high-pressure gas refrigerant
discharged from the compressor 3 passes through the refrigerant
flow switching device 4, and flows into the heat source-side heat
exchanger 1. During the defrosting operation, the heat source-side
heat exchanger 1 functions as a condenser. That is, in the heat
source-side heat exchanger 1, the heat of condensation of the
refrigerant circulated through the inside is transferred to frost
adhering to a surface of the heat source-side heat exchanger 1.
With this operation, the refrigerant circulated through the inside
of the heat source-side heat exchanger 1 is condensed to become the
high-pressure liquid refrigerant. Further, the frost adhering to
the surface of the heat source-side heat exchanger 1 is melted by
transfer heat from the refrigerant.
[0032] The high-pressure liquid refrigerant condensed by the heat
source-side heat exchanger 1 passes through the second pressure
reducing device 7, the intermediate pressure receiver 5, and the
first pressure reducing device 6 to become the low-pressure
two-phase refrigerant, and flows into the refrigerant flow passage
of the load-side heat exchanger 2. The load-side heat exchanger 2
functions as an evaporator during the defrosting operation. That
is, in the load-side heat exchanger 2, heat is exchanged between
the refrigerant flowing through the refrigerant flow passage and
the water flowing through the water flow passage, and heat of
evaporation of the refrigerant is received from the water. With
this operation, the refrigerant flowing through the refrigerant
flow passage of the load-side heat exchanger 2 evaporates to become
the low-pressure gas refrigerant. The gas refrigerant passes
through the refrigerant flow switching device 4 and the suction
pipe 11, and is sucked by the compressor 3. The refrigerant sucked
by the compressor 3 is compressed to become the high-temperature
and high-pressure gas refrigerant. In the defrosting operation, the
above-mentioned cycle is continuously repeated.
[0033] Next, the water circuit 210 is described. The water circuit
210 of Embodiment 1 is a closed circuit configured to circulate
water. In FIG. 1, the flow direction of the water is indicated by
outline arrows, The water circuit 210 is constructed by a water
circuit on the outdoor unit 100 side and a water circuit on the
indoor unit 200 side, which are connected to each other. The water
circuit 210 includes a main passage 220, a branch passage 221
constructing a hot water circuit, and a branch passage 222
constructing a part of a heater circuit. The main passage 220
constructs a part of the closed circuit. The branch passages 221
and 222 are each connected to the main passage 220 so as to be
branched from the main passage 220. The branch passages 221 and 222
are provided in parallel to each other. The branch passage 221
constructs the closed circuit together with the main passage 220.
The branch passage 222 constructs the closed circuit together with
the main passage 220, a heater 300 connected to the branch passage
222, and other units. The heater 300 is provided indoor space
separately from the indoor unit 200. As the heater 300, a radiator
or a floor heater is used, for example.
[0034] In Embodiment 1, water is taken as an example of a heat
medium circulated through the water circuit 210. However, as the
heat medium, other liquid heat media such as brine may be used.
[0035] The main passage 220 includes a strainer 56, a flow switch
57, the load-side heat exchanger 2, a booster heater 54, and a pump
53, which are connected to one another through water pipes. A drain
outlet 62 configured to drain water inside the water circuit 210 is
formed in a halfway part of the water pipes that construct the
water circuit 210. A downstream end of the main passage 220 is
connected to an inflow port of a three-way valve 55 (example of a
branching portion) having one inflow port and two outflow ports. At
the three-way valve 55, the branch passages 221 and 222 are
branched from the main passage 220. An upstream end of the main
passage 220 is connected to a joining portion 230. At the joining
portion 230, the branch passages 221 and 222 are joined to the main
passage 220. The water circuit 210 extending from the joining
portion 230 to the three-way valve 55 through the load-side heat
exchanger 2 and other units corresponds to the main passage
220.
[0036] The load-side heat exchanger 2 of the main passage 220 is
provided in the outdoor unit 100. Of the units of the main passage
220, units other than the load-side heat exchanger 2 are provided
in the indoor unit 200. That is, the main passage 220 of the water
circuit 210 is provided across the outdoor unit 100 and the indoor
unit 200. A part of the main passage 220 is provided in the outdoor
unit 100, and an other part of the main passage 220 is provided in
the indoor unit 200. The outdoor unit 100 and the indoor unit 200
are connected to each other through two connecting pipes 211 and
212 constructing parts of the main passage 220.
[0037] The pump 53 is a device configured to apply pressure to the
water inside the water circuit 210 to circulate the water through
the inside of the water circuit 210. The booster heater 54 is a
device configured to further heat the water inside the water
circuit 210 when, for example, the outdoor unit 100 has
insufficient heating capacity. The three-way valve 55 is a device
configured to switch a flow of the water inside the water circuit
210. For example, the three-way valve 55 switches a destination to
which the water inside the main passage 220 is to be circulated
between the branch passage 221 side and the branch passage 222
side. The strainer 56 is a device configured to remove scale inside
the water circuit 210. The flow switch 57 is a device configured to
detect whether or not the flow rate of the water circulated through
the inside of the water circuit 210 is equal to or larger than a
fixed amount. A flow rate sensor may also be used instead of the
flow switch 57.
[0038] A pressure relief valve 70 (example of a pressure protection
device) is connected to the booster heater 54. That is, the booster
heater 54 serves as a connecting portion for the pressure relief
valve 70 (example of the pressure protection device). In the
following, the connecting portion for the pressure relief valve 70
may be simply expressed as the "connecting portion". The pressure
relief valve 70 is a protection device configured to prevent
excessive rise of the pressure in the water circuit 210, which is
caused by temperature change of water. The pressure relief valve 70
is configured to release water to the outside of the water circuit
210 based on pressure in the water circuit 210. For example, when
the pressure in the water circuit 210 is increased to exceed a
pressure control range of an expansion tank 52 described later, the
pressure relief valve 70 is opened, and the water inside the water
circuit 210 is released to the outside through the pressure relief
valve 70. The pressure relief valve 70 is provided in the indoor
unit 200. The pressure relief valve 70 is provided in the indoor
unit 200 so as to protect the pressure in the water circuit 210 in
the indoor unit 200.
[0039] One end of a pipe 72, which is a water flow passage branched
from the main passage 220, is connected to a casing of the booster
heater 54. The pressure relief valve 70 is mounted to an other end
of the pipe 72. That is, the pressure relief valve 70 is connected
to the booster heater 54 through the pipe 72. The booster heater 54
serves as the connecting portion for connecting the pressure relief
valve 70 to the main passage 220. In the main passage 220, a water
temperature becomes the highest in the booster heater 54.
Therefore, the booster heater 54 is optimum as the connecting
portion for connecting the pressure relief valve 70. Further, when
the pressure relief valve 70 is connected to the branch passages
221 and 222, the pressure relief valve 70 needs to be provided for
each of the branch passages 221 and 222. In Embodiment 1, the
pressure relief valve 70 is connected to the main passage 220.
Therefore, it is only necessary to provide one pressure relief
valve 70.
[0040] A branching portion 72a is provided on a halfway part of the
pipe 72. One end of a pipe 75 is connected to the branching portion
72a. The expansion tank 52 is connected to an other end of the pipe
75. That is, the expansion tank 52 is connected to the booster
heater 54 through the pipes 75 and 72. The expansion tank 52 is a
device configured to control the pressure change inside the water
circuit 210, which is caused by temperature change of water, within
a predetermined range.
[0041] An interruption device 77 is provided downstream of the
load-side heat exchanger 2 as a first interruption device. The
interruption device 77 is provided in the main passage 220 at a
portion between the load-side heat exchanger 2 and the booster
heater 54, that is, the connecting portion for connecting the
pressure relief valve 70. As the interruption device 77, there may
be used an on-off valve such as a solenoid valve, a flow control
valve, or an electronic expansion valve. The interruption device 77
is in a closed state during the normal operation. When the
interruption device 77 is in the closed state, the interruption
device 77 interrupts a flow from the load-side heat exchanger 2
toward the booster heater 54. The interruption device 77 is
controlled by the controller 201 described later. When the
connecting portion for connecting the pressure relief valve 70 is
provided between the load-side heat exchanger 2 and the joining
portion 230, the interruption device 77 is provided as a second
interruption device in the main passage 220 at a portion between
the load-side heat exchanger 2 and the three-way valve 55
(branching portion).
[0042] An interruption device 78 is provided upstream of the
load-side heat exchanger 2 as the second interruption device. The
interruption device 78 is provided in the main passage 220 at a
portion between the load-side heat exchanger 2 and the joining
portion 230. As the interruption device 78, there may be used a
check valve configured to allow a flow of water from the joining
portion 230 to the load-side heat exchanger 2, and to interrupt a
flow from the load-side heat exchanger 2 to the joining portion
230. Further, as the interruption device 78, there may also be used
an on-off valve such as a solenoid valve, a flow control valve, or
an electronic expansion valve. When the on-off valve is used as the
interruption device 78, the interruption device 78 is controlled by
the controller 201 described later, or is operated in association
with the interruption device 77. When the connecting portion for
connecting the pressure relief valve 70 is provided between the
load-side heat exchanger 2 and the joining portion 230, the
interruption device 78 is provided as the first interruption device
in the main passage 220 at a portion between the load-side heat
exchanger 2 and the connecting portion.
[0043] A refrigerant leakage detection device 98 is provided
downstream of the interruption device 77. The refrigerant leakage
detection device 98 is connected to the main passage 220 at a
portion between the interruption device 77 and the booster heater
54 (connecting portion). The refrigerant leakage detection device
98 is a device configured to detect leakage of refrigerant from the
refrigerant circuit 110 to the water circuit 210. When the
refrigerant is leaked from the refrigerant circuit 110 to the water
circuit 210, the pressure in the water circuit 210 rises.
Therefore, the refrigerant leakage detection device 98 is capable
of detecting the leakage of the refrigerant into the water circuit
210 based on the pressure in the water circuit 210, that is, a
value of the pressure or temporal change of the pressure. As the
refrigerant leakage detection device 98, for example, a pressure
sensor or a pressure switch (high-pressure switch) configured to
detect the pressure in the water circuit 210 is used. For example,
the pressure switch may be an electric pressure switch or a
mechanical pressure switch using a diaphragm. The refrigerant
leakage detection device 98 is configured to output a detection
signal to the controller 201.
[0044] In Embodiment 1, both of the interruption devices 77 and 78
and the refrigerant leakage detection device 98 are provided in the
indoor unit 200. With this configuration, each of the interruption
devices 77 and 78 and the refrigerant leakage detection device 98
can be connected to the controller 201 through a control line in
the indoor unit 200. Thus, costs can be reduced. All of the
interruption devices 77 and 78 and the refrigerant leakage
detection device 98 may be provided in the outdoor unit 100. With
this configuration, each of the interruption devices 77 and 78 and
the refrigerant leakage detection device 98 can be connected to the
controller 101 through a control line in the outdoor unit 100.
Thus, costs can be reduced.
[0045] The branch passage 221 constructing the hot water circuit is
provided in the indoor unit 200. An upstream end of the branch
passage 221 is connected to one outflow port of the three-way valve
55. A downstream end of the branch passage 221 is connected to the
joining portion 230. A coil 61 is provided in the branch passage
221. The coil 61 is built in a hot-water storage tank 51 configured
to store water therein. The coil 61 is a heating unit configured to
heat the water accumulated in the hot-water storage tank 51 through
heat exchange with water (hot water) circulated through the branch
passage 221 of the water circuit 210. Further, the hot-water
storage tank 51 includes an immersion heater 60 built therein. The
immersion heater 60 is a heating unit configured to further heat
the water accumulated in the hot-water storage tank 51.
[0046] A sanitary circuit-side pipe 81a (for example, a hot water
pipe), which is to be connected to, for example, a shower, is
connected to an upper portion inside the hot-water storage tank 51.
A sanitary circuit-side pipe 81b (for example, a makeup water pipe)
is connected to a lower portion inside the hot-water storage tank
51. A drain outlet 63 configured to drain water in the hot-water
storage tank 51 is formed in a lower portion of the hot-water
storage tank 51. In order to prevent decrease in temperature of the
water inside the hot-water storage tank 51 due to heat transfer to
the outside, the hot-water storage tank 51 is covered with a heat
insulating material (not shown). Examples of the heat insulating
material to be used include felt, Thinsulate (trademark), and a
vacuum insulation panel (VIP).
[0047] The branch passage 222 constructing the part of the heater
circuit is provided in the indoor unit 200. The branch passage 222
includes a supply pipe 222a and a return pipe 222b. An upstream end
of the supply pipe 222a is connected to the other outflow port of
the three-way valve 55. A downstream end of the supply pipe 222a
and an upstream end of the return pipe 222b are connected to heater
circuit-side pipes 82a and 82b, respectively. A downstream end of
the return pipe 222b is connected to the joining portion 230. With
this configuration, the supply pipe 222a and the return pipe 222b
are connected to the heater 300 through the heater circuit-side
pipes 82a and 82b, respectively. The heater circuit-side pipes 82a
and 82b and the heater 300 are provided indoor space but outside
the indoor unit 200. The branch passage 222 constructs the heater
circuit together with the heater circuit-side pipes 82a and 82b and
the heater 300.
[0048] A pressure relief valve 301 is connected to the heater
circuit-side pipe 82a. The pressure relief valve 301 is a
protection device configured to prevent excessive rise of the
pressure in the water circuit 210, and, for example, has the
structure similar to that of the pressure relief valve 70. For
example, when the pressure in the heater circuit-side pipe 82a is
increased to exceed set pressure, the pressure relief valve 301 is
opened, and water in the heater circuit-side pipe 82a is released
to the outside through the pressure relief valve 301. The pressure
relief valve 301 is provided indoor space but outside the indoor
unit 200.
[0049] The heater 300, the heater circuit-side pipes 82a and 82b,
and the pressure relief valve 301 in Embodiment 1 are not parts of
the heat pump water heater 1000, but units installed by an on-site
installation worker depending on circumstances of each building.
For example, in an existing facility using a boiler as a heat
source device for the heater 300, the heat source device may be
replaced by the heat pump water heater 1000. In such a case, unless
it is inconvenient, the heater 300, the heater circuit-side pipes
82a and 82b, and the pressure relief valve 301 are used as they
are. Therefore, it is desired that the heat pump water heater 1000
be able to be connected to various facilities irrespective of
presence or absence of the pressure relief valve 301.
[0050] The indoor unit 200 includes the controller 201 configured
to mainly control an operation of the water circuit 210, for
example, the pump 53, the booster heater 54, the three-way valve
55, and the interruption device 77. The controller 201 includes a
microcomputer including a CPU, a ROM, a RAM, and an I/O port. The
controller 201 can communicate with the controller 101 and the
operation unit 202. The controller 201, for example, sets the
interruption device 77 to the closed state when the controller 201
detects the leakage of the refrigerant into the water circuit 210
based on the detection signal from the refrigerant leakage
detection device 98. When the refrigerant leakage detection device
98 is configured to output a contact signal at the time of the
leakage of the refrigerant, the refrigerant leakage detection
device 98 may be directly connected to the interruption device 77
without connection through the controller 201.
[0051] The operation unit 202 allows a user to conduct the
operation or various settings of the heat pump water heater 1000.
The operation unit 202 of Embodiment 1 includes a display unit 203.
The display unit 203 can display various kinds of information
including a state of the heat pump water heater 1000. The operation
unit 202 is provided, for example, on a surface of the casing of
the indoor unit 200.
[0052] Next, description is made of an operation in a case where
the partition wall configured to partition the refrigerant flow
passage and the water flow passage in the load-side heat exchanger
2 is broken. The load-side heat exchanger 2 functions as an
evaporator during the defrosting operation. Therefore, the
partition wall of the load-side heat exchanger 2 may be broken due
to freezing of water or other causes particularly during the
defrosting operation. In general, the pressure of the refrigerant
flowing through the refrigerant flow passage of the load-side heat
exchanger 2 is higher than the pressure of the water flowing
through the water flow passage of the load-side heat exchanger 2
both during the normal operation and during the defrosting
operation. Therefore, when the partition wall of the load-side heat
exchanger 2 is broken, the refrigerant in the refrigerant flow
passage flows out to the water flow passage both during the normal
operation and during the defrosting operation, and the refrigerant
is mixed into the water inside the water flow passage. At this
time, the refrigerant mixed into the water is gasified due to
pressure decrease. Further, the refrigerant having the pressure
higher than that of the water is mixed into the water, with the
result that the pressure in the water circuit 210 is increased.
[0053] The refrigerant mixed into the water inside the water
circuit 210 in the load-side heat exchanger 2 not only flows in a
direction along a flow of water at a normal time, that is, a
direction from the load-side heat exchanger 2 toward the booster
heater 5, but, due to a pressure difference, also flows in a
direction opposite to the direction along the flow of water at the
normal time, that is, a direction from the load-side heat exchanger
2 toward the joining portion 230. When the pressure relief valve 70
is provided in the main passage 220 of the water circuit 210 as in
Embodiment 1, the refrigerant mixed into the water may be released
from the pressure relief valve 70 to a room together with the
water. Further, when the pressure relief valve 301 is provided in
the heater circuit-side pipe 82a or the heater circuit-side pipe
82b as in Embodiment 1, the refrigerant mixed into the water may be
released from the pressure relief valve 301 to the room together
with the water. That is, both of the pressure relief valves 70 and
301 function as valves configured to release the refrigerant mixed
into the water inside the water circuit 210 to the outside of the
water circuit 210. When the refrigerant has flammability, there is
a fear in that a flammable concentration region may be generated in
the room due to the refrigerant released to the room.
[0054] However, in Embodiment 1, the interruption device 77 is
provided between the load-side heat exchanger 2 and the booster
heater 54. Thus, a flow of the refrigerant from the load-side heat
exchanger 2 to the booster heater 54 can be interrupted. Therefore,
leakage of the refrigerant from the pressure relief valve 70 to the
room can be prevented. Further, in Embodiment 1, the interruption
device 78 is provided between the load-side heat exchanger 2 and
the joining portion 230. Thus, a flow of the refrigerant from the
load-side heat exchanger 2 to the joining portion 230 can be
interrupted. Therefore, leakage of the refrigerant from the
pressure relief valve 301 to the room can be prevented.
[0055] FIG. 2 is a circuit diagram for illustrating a schematic
configuration of a heat pump use apparatus of a modification
example of Embodiment 1. As illustrated in FIG. 2, this
modification example is different from the configuration
illustrated in FIG. 1 in that the load-side heat exchanger 2 is
accommodated in the indoor unit 200. The refrigerant circuit 110 is
provided across the outdoor unit 100 and the indoor unit 200. A
part of the refrigerant circuit 110 is provided in the outdoor unit
100, and an other part of the refrigerant circuit 110 is provided
in the indoor unit 200. The outdoor unit 100 and the indoor unit
200 are connected to each other through two connecting pipes 111
and 112 constructing parts of the refrigerant circuit 110. Also
according to this modification example, effects similar to those of
the configuration illustrated in FIG. 1 can be obtained. Further,
in this modification example, all of the interruption devices 77
and 78 and the refrigerant leakage detection device 98 are provided
in the indoor unit 200. With this configuration, each of the
interruption devices 77 and 78 and the refrigerant leakage
detection device 98 can be connected to the controller 201 through
the control line in the indoor unit 200. Thus, costs can be
reduced.
[0056] Next, an arrangement position of the refrigerant leakage
detection device 98 is described. FIG. 3 to FIG. 6 are explanatory
views for illustrating examples of the arrangement position of the
refrigerant leakage detection device 98 in the heat pump use
apparatus according to Embodiment 1. In FIG. 3, as the examples of
the arrangement position of the refrigerant leakage detection
device 98, four arrangement positions A to D are illustrated. When
the refrigerant leakage detection device 98 is arranged at the
arrangement position A or B, the refrigerant leakage detection
device 98 is connected to the pipe 72. That is, similarly to the
pressure relief valve 70, the refrigerant leakage detection device
98 is connected to the main passage 220 at the booster heater 54
(connecting portion). In such a case, before the refrigerant, which
is leaked to the water circuit 210 at the load-side heat exchanger
2, is released from the pressure relief valve 70, the leakage of
the refrigerant can reliably be detected by the refrigerant leakage
detection device 98. The similar effect is obtained also when the
refrigerant leakage detection device 98 is connected to the main
passage 220 at the load-side heat exchanger 2, a portion between
the load-side heat exchanger 2 and the booster heater 54, or the
booster heater 54.
[0057] Further, the refrigerant is gasified at a time point when
the refrigerant is leaked to the water circuit 210. Therefore, due
to a difference in specific volume between gas and a liquid, mass
velocity when the refrigerant is leaked from the pressure relief
valve 70 is reduced to about one thousandth of that when the liquid
refrigerant is leaked. Therefore, an amount of the refrigerant,
which may be released from the pressure relief valve 70 during a
time period from detection of the leakage of the refrigerant to
interruption of a flow at the interruption device 77, does not
reach an amount which leads to generation of the flammable
concentration region in the room.
[0058] Meanwhile, when the refrigerant leakage detection device 98
is arranged at the arrangement position C or D, the refrigerant
leakage detection device 98 is connected to the main passage 220 at
a portion between the booster heater 54 (connecting portion) and
the three-way valve 55. In this case, before the leakage of the
refrigerant is detected by the refrigerant leakage detection device
98, the refrigerant may be released from the pressure relief valve
70. However, due to the difference in specific volume between gas
and a liquid as described above, the amount of the refrigerant that
may be released from the pressure relief valve 70 does not reach
the amount which leads to the generation of the flammable
concentration region in the room.
[0059] Further, as illustrated in FIG. 4, when the refrigerant
leakage detection device 98 is provided between the load-side heat
exchanger 2 and the interruption device 77, through the setting of
the interruption device 77 to the closed state immediately after
the leakage of the refrigerant is detected, the amount of the
refrigerant released from the pressure relief valve 70 can be
reduced to almost exactly zero. Similarly, as illustrated in FIG.
5, when the refrigerant leakage detection device 98 is provided
between the load-side heat exchanger 2 and the interruption device
78, an amount of the refrigerant released from the pressure relief
valve 301 can be reduced to almost exactly zero. That is, in order
to reduce the amount of the refrigerant released to the room to
almost exactly zero, it is desired that the refrigerant leakage
detection device 98 be connected to the main passage 220 at a
portion between the interruption device 77 and the interruption
device 78.
[0060] Further, as illustrated in FIG. 6, when the interruption
device 78 is not the check valve but the on-off valve, the
refrigerant leakage detection device 98 may be connected to the
main passage 220 at a portion between the interruption device 78
and the joining portion 230.
[0061] In all of the configurations illustrated in FIG. 1 to FIG.
6, the refrigerant leakage detection device 98 is not connected to
the branch passage, for example, the heater circuit-side pipe 82a
or 82b or the heater 300, which is installed by an on-site
installation worker, but is connected to the main passage 220.
Therefore, mounting of the refrigerant leakage detection device 98
and connection between the refrigerant leakage detection device 98
and the controller 201 can be carried out by a manufacturer of the
indoor unit 200. Therefore, it is possible to avoid such a human
error as to forget to mount the refrigerant leakage detection
device 98 and connect the refrigerant leakage detection device
98.
[0062] As described above, the heat pump water heater 1000 (example
of the heat pump use apparatus) according to Embodiment 1 includes
the refrigerant circuit 110 configured to circulate the
refrigerant, the water circuit 210 (example of the heat medium
circuit) configured to allow water (example of the heat medium) to
flow therethrough, and the load-side heat exchanger 2 (example of
the heat exchanger) configured to exchange heat between the
refrigerant and the water. The water circuit 210 includes the main
passage 220 extending through the load-side heat exchanger 2. The
main passage 220 includes the three-way valve 55 (example of the
branching portion) to which the plurality of branch passages 221
and 222 branched from the main passage 220 are connected, and the
joining portion 230 at which the plurality of branch passages 221
and 222 are connected to each other to be joined to the main
passage 220. The three-way valve 55 is provided at the downstream
end of the main passage 220. The joining portion 230 is provided at
the upstream end of the main passage 220. The pressure relief valve
70 (example of the pressure protection device) and the refrigerant
leakage detection device 98 are connected to the main passage 220.
The pressure relief valve 70 is configured to release water to the
outside of the water circuit 210 based on the pressure in the water
circuit 210. The refrigerant leakage detection device 98 is
configured to detect the leakage of the refrigerant from the
refrigerant circuit 110 to the water circuit 210. The pressure
relief valve 70 is connected to the main passage 220 at the booster
heater 54 (example of the connecting portion) located between the
load-side heat exchanger 2 and one of the three-way valve 55 and
the joining portion 230. The interruption device 77 (example of the
first interruption device) configured to be able to interrupt a
flow from the load-side heat exchanger 2 to the booster heater 54
is provided in the main passage 220 at a portion between the
load-side heat exchanger 2 and the booster heater 54. The
interruption device 78 (example of the second interruption device)
configured to be able to interrupt a flow from the load-side heat
exchanger 2 to an other of the three-way valve 55 and the joining
portion 230 is provided in the main passage 220 at a portion
between the load-side heat exchanger 2 and the other of the
three-way valve 55 and the joining portion 230.
[0063] According to this configuration, even when the refrigerant
is leaked to the water circuit 210 in the load-side heat exchanger
2, a flow of the refrigerant mixed into the water can be
interrupted by the interruption devices 77 and 78. Therefore, the
leakage of the refrigerant from the pressure relief valve 70 to the
room can be prevented. Further, there can also be prevented the
leakage of the refrigerant to the room from the pressure relief
valve 301 which may be provided to a circuit provided ahead of the
branching portion, for example, the heater circuit-side pipes 82a
and 82b.
[0064] In the heat pump water heater 1000 according to Embodiment
1, each of the interruption devices 77 and 78 is the on-off valve
which is closed when the leakage of the refrigerant into the water
circuit 210 is detected. According to this configuration, when the
refrigerant is leaked to the water circuit 210, the flow of the
refrigerant mixed into the water can further reliably be
interrupted.
[0065] In the heat pump water heater 1000 according to Embodiment
1, the refrigerant leakage detection device 98 is connected to the
main passage 220 at the joining portion 230, a portion between the
joining portion 230 and the booster heater 54, or the booster
heater 54. According to this configuration, the leakage of the
refrigerant can reliably be detected before the refrigerant leaked
to the water circuit 210 is released to the room.
[0066] In the heat pump water heater 1000 according to Embodiment
1, of the interruption devices 77 and 78, the interruption device
78, which is provided between the load-side heat exchanger 2 and
the joining portion 230, is the check valve. Further, the
refrigerant leakage detection device 98 is connected to the main
passage 220 at a portion between the check valve and the booster
heater 54 or at the booster heater 54, According to this
configuration, the leakage of the refrigerant can reliably be
detected before the refrigerant leaked to the water circuit 210 is
released to the room.
[0067] In the heat pump water heater 1000 according to Embodiment
1, the refrigerant leakage detection device 98 is connected to the
main passage 220 at a portion between the interruption device 77
and the interruption device 78. According to this configuration,
the amount of the refrigerant released from the pressure relief
valve can be reduced to almost exactly zero.
[0068] In the heat pump water heater 1000 according to Embodiment
1, the refrigerant leakage detection device 98 is configured to
detect the leakage of the refrigerant into the water circuit 210
based on the pressure in the water circuit 210. According to this
configuration, the leakage of the refrigerant can reliably be
detected.
[0069] The heat pump water heater 1000 according to Embodiment 1
further includes the outdoor unit 100 accommodating the refrigerant
circuit 110, a part of the water circuit 210, and the load-side
heat exchanger 2, and the indoor unit 200 accommodating an other
part of the water circuit 210. One of the outdoor unit 100 and the
indoor unit 200 accommodates the interruption devices 77 and 78 and
the refrigerant leakage detection device 98. According to this
configuration, the controller 101 or the controller 201 can be
connected to each of the interruption devices 77 and 78 and the
refrigerant leakage detection device 98 in the outdoor unit 100 or
the indoor unit 200. Thus, costs can be reduced.
[0070] The heat pump water heater 1000 according to Embodiment 1
further includes the outdoor unit 100 accommodating a part of the
refrigerant circuit 110, and the indoor unit 200 accommodating an
other part of the refrigerant circuit 110, the water circuit 210,
and the load-side heat exchanger 2. The indoor unit 200
accommodates the interruption devices 77 and 78 and the refrigerant
leakage detection device 98. According to this configuration, the
controller 201 can be connected to each of the interruption devices
77 and 78 and the refrigerant leakage detection device 98 in the
indoor unit 200. Thus, costs can be reduced.
[0071] In the heat pump water heater 1000 according to Embodiment
1, the refrigerant may be flammable refrigerant or toxic
refrigerant.
Embodiment 2
[0072] A heat pump use apparatus according to Embodiment 2 of the
present invention is described. FIG. 7 is a circuit diagram for
illustrating a schematic configuration of the heat pump use
apparatus according to Embodiment 2. In FIG. 7, a configuration of
the indoor unit 200 is mainly illustrated. Components having the
same functions and actions as those of Embodiment 1 are denoted by
the same reference symbols, and description thereof is omitted. As
illustrated in FIG. 7, in Embodiment 2, a boiler circuit 240
configured to heat water accumulated inside the hot-water storage
tank 51 is provided outside the hot-water storage tank 51. The
boiler circuit 240 includes a water flow passage for connecting a
lower portion and an upper portion of the hot-water storage tank
51. The boiler circuit 240 includes a boiler pump 241 and a boiler
heat exchanger 242 configured to exchange heat between water
flowing through the boiler circuit 240 and water flowing through
the branch passage 221. When the boiler pump 241 is operated, water
in the lower portion of the hot-water storage tank 51 flows into
the boiler circuit 240. The water flowing into the boiler circuit
240 is heated through heat exchange in the boiler heat exchanger
242, and is returned to the upper portion of the hot-water storage
tank 51. Also according to Embodiment 2, effects similar to those
of Embodiment 1 can be obtained.
[0073] The present invention is not limited to the above-mentioned
embodiments, and various modifications may be made thereto.
[0074] For example, in the above-mentioned embodiments, the plate
heat exchanger is given as an example of the load-side heat
exchanger 2. However, the load-side heat exchanger 2 may be a heat
exchanger other than the plate heat exchanger, such as a
double-pipe heat exchanger as long as the heat exchanger is
configured to exchange heat between refrigerant and a heat
medium.
[0075] Further, in the above-mentioned embodiments, the heat pump
water heater 1000 is given as an example of the heat pump use
apparatus. However, the present invention is also applicable to
other heat pump use apparatus, such as a chiller.
[0076] Further, in the above-mentioned embodiments, the indoor unit
200 including the hot-water storage tank 51 is given as an example.
However, the hot-water storage tank may be provided separately from
the indoor unit 200.
[0077] The embodiments described above and the modification may be
carried out in combinations.
REFERENCE SIGNS LIST
[0078] 1 heat source-side heat exchanger 2 load-side heat exchanger
3 compressor 4 refrigerant flow switching device 5 intermediate
pressure receiver
[0079] 6 first pressure reducing device 7 second pressure reducing
device 11 suction pipe 51 hot-water storage tank 52 expansion tank
53 pump 54 booster heater 55 three-way valve 56 strainer 57 flow
switch 60 immersion heater 61 coil 62, 63 drain outlet 70 pressure
relief valve 72 pipe 72a branching portion 75 pipe 77, 78
interruption device 81a, 81b sanitary circuit-side pipe 82a, 82b
heater circuit-side pipe 98 refrigerant leakage detection device
100 outdoor unit 101 controller 102 control line
[0080] 110 refrigerant circuit 111, 112 connecting pipe 200 indoor
unit
[0081] 201 controller 202 operation unit 203 display unit 210 water
circuit 211 212 connecting pipe 220 main passage 221, 222 branch
passage 222a supply pipe 222b return pipe 230 joining portion 240
boiler circuit 241 boiler pump 242 boiler heat exchanger 300 heater
301 pressure relief valve 1000 heat pump water heater
* * * * *