U.S. patent application number 16/469229 was filed with the patent office on 2019-12-26 for heat-pump using apparatus.
The applicant listed for this patent is Mitsubishi Electric Corporation. Invention is credited to Yasuhiro SUZUKI.
Application Number | 20190390884 16/469229 |
Document ID | / |
Family ID | 63371378 |
Filed Date | 2019-12-26 |
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United States Patent
Application |
20190390884 |
Kind Code |
A1 |
SUZUKI; Yasuhiro |
December 26, 2019 |
HEAT-PUMP USING APPARATUS
Abstract
A heat-pump using apparatus includes a refrigerant circuit, a
heat medium circuit, and a heat exchanger which causes heat
exchange to be performed between refrigerant and a heat medium. A
main circuit of the heat medium circuit includes a branching part
and a joining part. To the main circuit, a pressure protection
device and a refrigerant leakage detecting device are connected.
The pressure protection device is connected to a connection part
located between the heat exchanger and one of the branching part
and the joining part in the main circuit. The refrigerant circuit
includes a first blocking device and a second blocking device
between which the heat exchanger is located.
Inventors: |
SUZUKI; Yasuhiro; (Tokyo,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Mitsubishi Electric Corporation |
Tokyo |
|
JP |
|
|
Family ID: |
63371378 |
Appl. No.: |
16/469229 |
Filed: |
February 28, 2017 |
PCT Filed: |
February 28, 2017 |
PCT NO: |
PCT/JP2017/008001 |
371 Date: |
June 13, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F25B 2500/222 20130101;
F25B 2600/0251 20130101; F25B 2600/2513 20130101; F25B 49/005
20130101; F25B 49/02 20130101; F25B 2313/003 20130101; F24H 4/04
20130101; F25B 2339/047 20130101; F25B 2600/2519 20130101; F25B
2400/12 20130101; F24H 9/165 20130101 |
International
Class: |
F25B 49/00 20060101
F25B049/00; F25B 49/02 20060101 F25B049/02 |
Claims
1. A heat-pump using apparatus comprising: a refrigerant circuit
configured to circulate refrigerant; a heat medium circuit
configured to cause a heat medium to flow in the heat medium
circuit; and a heat exchanger configured to cause heat exchange to
be performed between the refrigerant and the heat medium, the heat
medium circuit including a main circuit extending via the heat
exchanger, the main circuit including a branching part located at a
downstream end of the main circuit, and connected to those portions
of a plurality of branch circuits which branch off from the main
circuit, and a joining part located at an upstream end of the main
circuit, and connected to those portions of the plurality of branch
circuits which join the main circuit, the main circuit being
provided as a circuit to which a pressure protection device and a
refrigerant leakage detecting device are connected, the refrigerant
circuit including a first blocking device and a second blocking
device between which the heat exchanger is located, the pressure
protection device being connected to a connection part located
between the heat exchanger and one of the branching part and the
joining part in the main circuit, the refrigerant leakage detecting
device being connected to the other of the branching part and the
joining part, or between the connection part and the other of the
branching part and the joining part, or to the connection part, in
the main circuit.
2. The heat-pump using apparatus of claim 1, wherein the first
blocking device and the second blocking device are opening and
closing valves which are closed when leakage of the refrigerant to
the heat medium circuit is detected.
3. (canceled)
4. The heat-pump using apparatus of claim 1, wherein the
refrigerant leakage detecting device detects leakage of the
refrigerant to the heat medium circuit based on an internal
pressure of the heat medium circuit.
5. The heat-pump using apparatus of claim 1, wherein the first
blocking device is provided between a compressor in the refrigerant
circuit and the heat exchanger, and wherein the second blocking
device is provided between the heat exchanger and a
heat-source-side heat exchanger in the refrigerant circuit.
6. The heat-pump using apparatus of claim 5, wherein the second
blocking device operates as a pressure-reducing device in the
refrigerant circuit.
7. The heat-pump using apparatus of claim 1, further comprising: an
outdoor unit accommodating the refrigerant circuit, part of the
heat medium circuit and the heat exchanger; and an indoor unit
accommodating a remaining part of the heat medium circuit, wherein
the outdoor unit further accommodates the first blocking device,
the second blocking device and the refrigerant leakage detecting
device.
8. The heat-pump using apparatus of claim 1, further comprising: an
outdoor unit accommodating part of the refrigerant circuit; and an
indoor unit accommodating a remaining part of the refrigerant
circuit, the heat medium circuit and the heat exchanger, wherein
the indoor unit further accommodates the first blocking device, the
second blocking device and the refrigerant leakage detecting
device.
9. The heat-pump using apparatus of claim 1, wherein the
refrigerant is flammable refrigerant or toxic refrigerant.
Description
TECHNICAL FIELD
[0001] The present invention relates to a heat-pump using apparatus
including a refrigerant circuit and a heat medium circuit.
BACKGROUND ART
[0002] Patent Literature 1 describes an outdoor unit of a heat-pump
cycle apparatus using flammable refrigerant. The outdoor unit
includes a refrigerant circuit in which a compressor, an air heat
exchanger, an expansion device and a water heat exchanger are
connected by pipes, and a pressure relief valve which prevents an
excessive increase in hydraulic pressure in a water circuit for
supplying water heated by the water heat exchanger. Thereby, even
if a partition wall which isolates the refrigerant circuit and the
water circuit from each other in the water heat exchanger is
broken, and the flammable refrigerant thus enters the water
circuit, the flammable refrigerant can be discharged to the
outdoors via 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 using apparatus such as a heat-pump cycle
apparatus, in general, a pressure relief valve of a water circuit
is provided in an indoor unit. In the heat-pump using apparatus,
there are various combinations of outdoor and indoor units. For
example, in a given case, an outdoor unit and an indoor unit
manufactured by the same manufacturer are combined together, and in
another case, an outdoor unit and an indoor unit manufactured by
different manufacturers are combined. Therefore, the outdoor unit
described in Patent Literature 1 may be combined with an indoor
unit equipped with a pressure relief valve.
[0005] However, in the above case, if refrigerant leaks into the
water circuit, refrigerant which mixes with water in the water
circuit may be discharged not only from a pressure relief valve
provided in the outdoor unit, but from a pressure relief valve
disposed in the indoor unit. Therefore, there is a risk that the
refrigerant will leak from the water circuit into a room.
[0006] The present invention aims to solve the above problem, and
provide a heat-pump using apparatus which can prevent leaking
refrigerant from entering a room.
Solution to Problem
[0007] A heat-pump using apparatus according to an embodiment of
the present invention includes a refrigerant circuit which
circulates refrigerant; a heat medium circuit which causes a heat
medium to flow therein; and a heat exchanger which causes heat
exchange to be performed between the refrigerant and the heat
medium. The heat medium circuit includes a main circuit extending
via the heat exchanger. The main circuit includes a branching part
which is located at a downstream end of the main circuit, and
connected to those portions of a plurality of branch circuits which
branch off from the main circuit are connected, the branching part
being provided at a downstream end of the main circuit, and a
joining part which is located at an upstream end of the main
circuit, and connected to those portions of the plurality of branch
which join the main circuit. To the main circuit, a pressure
protection device and a refrigerant leakage detecting device are
connected. The main circuit includes a first blocking device and a
second blocking device between which the heat exchanger is
located.
Advantageous Effects of Invention
[0008] According to an embodiment of the present invention, even in
the case where refrigerant leaks into a heat medium circuit, the
flow of the refrigerant in a refrigerant circuit can be blocked by
a first blocking device and a second blocking device. It is
therefore possible to reduce leakage of refrigerant from a pressure
protection device into indoor space.
BRIEF DESCRIPTION OF DRAWINGS
[0009] FIG. 1 is a circuit diagram illustrating a schematic
configuration of a heat-pump using apparatus according to
embodiment 1 of the present invention.
[0010] FIG. 2 is a circuit diagram illustrating a schematic
configuration of a heat-pump using apparatus according to a
modification of embodiment 1 of the present invention.
[0011] FIG. 3 is an explanatory diagram illustrating examples of
the position of a refrigerant leakage detecting device 98 in the
heat-pump using apparatus according to embodiment 1 of the present
invention.
[0012] FIG. 4 is a circuit diagram illustrating a schematic
configuration of a heat-pump using apparatus according to
embodiment 2 of the present invention.
DESCRIPTION OF EMBODIMENTS
Embodiment 1
[0013] A heat-pump using apparatus according to embodiment 1 of the
present invention will be described. FIG. 1 is a circuit diagram
illustrating a schematic configuration of the heat-pump using
apparatus according to embodiment 1. In embodiment 1, a heat-pump
hot-water supply heating apparatus 1000 is provided as an example
of the heat-pump using apparatus. In figures including FIG. 1 which
are to be referred to below, the relationships in size, shape, etc.
between structural components may be different from actual
ones.
[0014] As illustrated in FIG. 1, the heat-pump hot-water supply
heating apparatus 1000 includes a refrigerant circuit 110 in which
refrigerant is circulated and a water circuit 210 in which water is
made to flow. The heat-pump hot-water supply heating apparatus 1000
further includes an outdoor unit 100 installed outside an indoor
space (outdoors, for example) and an indoor unit 200 installed in
the indoor space. The indoor unit 200 is installed in, for example,
a kitchen, a bathroom, a laundry room, or a storage space such as a
closet in a building.
[0015] In the refrigerant circuit 110, a compressor 3, a
refrigerant flow switching device 4, a load-side heat exchanger 2,
a pressure-reducing device 6 and a heat-source-side heat exchanger
1 are successively connected by refrigerant pipes. The refrigerant
circuit 110 of the heat-pump hot-water supply heating apparatus
1000 is capable of performing a normal operation (for example, a
heating and hot-water supplying operation) in which water flowing
in the water circuit 210 is heated and a defrosting operation in
which refrigerant is caused to flow in an opposite direction to the
flow direction of the refrigerant in the normal operation to
defrost the heat-source-side heat exchanger 1.
[0016] The compressor 3 is a fluid machine which compresses
low-pressure refrigerant sucked therein, and discharges the
refrigerant as high-pressure refrigerant. In this embodiment, the
compressor 3 includes, for example, an inverter device, and can
vary a capacity (the amount of refrigerant to be sent unit time) by
arbitrarily changing a driving frequency.
[0017] The refrigerant flow switching device 4 switches the flow
direction of the refrigerant in the refrigerant circuit 110 between
that in the normal operation and that in the defrosting operation.
For example, a four-way valve is used as the refrigerant flow
switching device 4.
[0018] The load-side heat exchanger 2 is a water-refrigerant heat
exchanger which causes heat exchange to be performed between
refrigerant flowing in the refrigerant circuit 110 and water
flowing in the water circuit 210. For example, a plate heat
exchanger is used as the load-side heat exchanger 2. The load-side
heat exchanger 2 includes a refrigerant passage which allows
refrigerant to flow therethrough, as part of the refrigerant
circuit 110, a water passage which allows water to flow
therethrough as part of the water circuit 210, and a thin-plate
partition wall which isolates the refrigerant passage and the water
passage from each other. The load-side heat exchanger 2 operates as
a condenser (heat-transferring device) which heats water during the
normal operation, and transfers condensation heat of refrigerant to
water, and operates as an evaporator (heat-receiving device) during
the defrosting operation.
[0019] The pressure-reducing device 6 adjusts the flow rate of
refrigerant, and, for example, adjusts the pressure of refrigerant
flowing in the load-side heat exchanger 2. The pressure-reducing
device 6 in embodiment 1 is an electronic expansion valve whose
opening degree can be varied in response to an instruction from a
controller 101, which will be described below. For example, a
thermosensitive expansion valve (for example, a thermosensitive
expansion valve integrated with a solenoid valve) can be used as
the pressure-reducing device 6.
[0020] The heat-source-side heat exchanger 1 is an air-refrigerant
heat exchanger which causes heat exchange to be performed between
refrigerant flowing through the refrigerant circuit 110 and outdoor
air sent by an outdoor fan (not illustrated) or other devices. The
heat-source-side heat exchanger 1 operates as an evaporator
(heat-receiving device) during the normal operation, and operates
as a condenser (heat-transfer device) during the defrosting
operation.
[0021] As a first blocking device, a blocking device 77 is provided
upstream of the load-side heat exchanger 2 in the flow of the
refrigerant in the normal operation. In the flow of the refrigerant
in the normal operation, the blocking device 77 is located
downstream of the compressor 3 and upstream of the load-side heat
exchanger 2 in the refrigerant circuit 110. In the case where the
refrigerant flow switching device 4 is provided as in embodiment 1,
it is preferable that the blocking device 77 be located downstream
of the refrigerant flow switching device 4 and upstream of the
load-side heat exchanger 2 in the refrigerant circuit 110 in the
flow of the refrigerant in the normal operation. As the blocking
device 77, an opening and closing valve (for example, a solenoid
valve, a flow control valve or an electronic expansion valve) which
is to be controlled by the controller 101 to be described later is
used. The blocking device 77 is in an opened state during the
operation of the refrigerant circuit 110, which includes the normal
operation and the defrosting operation. When the blocking device 77
is made to be in a closed state by the control by the controller
101, the blocking device 77 blocks the flow of the refrigerant.
[0022] Furthermore, as a second blocking device, a blocking device
78 is provided downstream of the load-side heat exchanger 2 in the
flow of the refrigerant in the normal operation. The blocking
device 78 is provided downstream of the load-side heat exchanger 2
and upstream of the heat-source-side heat exchanger 1 in the
refrigerant circuit 110 in the flow of the refrigerant in the
normal operation. As the blocking device 78, an opening and closing
valve (for example, a solenoid valve, a flow-rate control valve or
an electronic expansion valve) which is to be controlled by the
controller 101 to be described later is used. The blocking device
78 is in the opened state during the operation of the refrigerant
circuit 110, which includes the normal operation and the defrosting
operation. When set in the closed state by the control by the
controller 101, the blocking device 78 blocks the flow of the
refrigerant.
[0023] In the case where the pressure-reducing device 6 is an
electronic expansion valve or a thermosensitive expansion valve
integrated with a solenoid valve, the pressure-reducing device 6
can double as the blocking device 78. That is, in the case where
the pressure-reducing device 6 is an electronic expansion valve or
a thermosensitive expansion valve integrated with a solenoid valve,
it is possible to omit the blocking device 78, and also use the
pressure-reducing device 6 as a second blocking device. In other
words, in the case where the blocking device 78 is an electronic
expansion valve or a thermosensitive expansion valve integrated
with a solenoid valve, it is possible to omit the pressure-reducing
device 6, and cause the blocking device 78 to double as a
pressure-reducing device.
[0024] For example, a slightly flammable refrigerant such as
R1234yf or R1234ze(E) or a highly flammable refrigerant such as
R290 or R1270 is used as the refrigerant circulating in the
refrigerant circuit 110. Each of these refrigerants may be used as
a single refrigerant, or two or more of them may be mixed and used
as a mixed refrigerant. Hereinafter, there is a case where a
refrigerant having flammability of at least a slightly flammable
level (at least 2 L under ASHRAE34 classification, for example)
will be referred to as "refrigerant having flammability" or
"flammable refrigerant." Furthermore, an inflammable refrigerant
having inflammability (1 under ASHRAE34 classification, for
example) such as R4070 or R410A can be used as refrigerant to be
circulated in the refrigerant circuit 110. These refrigerants have
a higher density than air under atmospheric pressure (when the
temperature is room temperature (25 degrees Celsius), for example).
Furthermore, refrigerant having toxicity, such as R717 (ammonia),
can be used as the refrigerant to be circulated in the refrigerant
circuit 110.
[0025] The refrigerant circuit 110 including the compressor 3, the
refrigerant flow switching device 4, the blocking device 77, the
load-side heat exchanger 2, the blocking device 78, the
pressure-reducing device 6 and the heat-source-side heat exchanger
1 is provided in the outdoor unit 100.
[0026] Furthermore, the controller 101, which performs control
manly of an operation of the refrigerant circuit 110 (for example,
the compressor 3, the refrigerant flow switching device 4, the
blocking devices 77 and 78, the pressure-reducing device 6 and an
outdoor fan not illustrated) is provided in the outdoor unit 100.
The controller 101 is capable of communicating, via a control line
102, with a controller 201 and an operation unit 202, which will be
described later.
[0027] An example of the operation of the refrigerant circuit 110
will be described. In FIG. 1, solid arrows indicate the flow
direction of refrigerant in the refrigerant circuit 110 in the
normal operation. In the normal operation, the refrigerant flow
switching device 4 switches refrigerant passages as indicated by
the solid arrows, and the refrigerant circuit 110 is configured
such that high-temperature, high-pressure refrigerant flows into
the load-side heat exchanger 2.
[0028] The high-temperature, high-pressure gas refrigerant
discharged from the compressor 3 passes through the refrigerant
flow switching device 4 and the blocking device 77 being in the
opened state, and flows into the refrigerant passage of the
load-side heat exchanger 2. In the normal operation, the load-side
heat exchanger 2 operates as a condenser. That is, the load-side
heat exchanger 2 causes heat exchange to be carried out between
refrigerant flowing through the refrigerant passage and water
flowing through the water passage, and the condensation heat of the
refrigerant is transferred to the water. Thereby, the refrigerant
flowing through the refrigerant passage of the load-side heat
exchanger 2 condenses and changes into high-pressure liquid
refrigerant. Furthermore, the water flowing through the water
passage of the load-side heat exchanger 2 is heated by the heat
transferred from the refrigerant.
[0029] The high-pressure liquid refrigerant condensed at the
load-side heat exchanger 2 flows into the pressure-reducing device
6 via the blocking device 78 being in the opened state, and is
reduced in pressure to change into low-pressure, two-phase
refrigerant. The low-pressure, two-phase refrigerant flows into the
heat-source-side heat exchanger 1. In the normal operation, the
heat-source-side heat exchanger 1 operates as an evaporator. To be
more specific, in the heat-source-side heat exchanger 1, heat
exchange is carried out between the refrigerant flowing therein and
the outdoor air sent by the outdoor fan, whereby the evaporation
heat of the refrigerant is received by the outdoor air. By virtue
of this configuration, the refrigerant having flowed into the
heat-source-side heat exchanger 1 evaporates and changes into
low-pressure gas refrigerant. The low-pressure gas refrigerant is
sucked into the compressor 3 via the refrigerant flow switching
device 4. The refrigerant sucked into the compressor 3 is
compressed and changes into high-temperature, high-pressure gas
refrigerant. In the normal operation, the above cycle is
continuously repeated.
[0030] It will be described by way of example what operation is
performed during the defrosting operation. In FIG. 1, broken arrows
indicate the flow direction of the refrigerant in the refrigerant
circuit 110 in the defrosting operation. In the defrosting
operation, the refrigerant flow switching device 4 switches the
refrigerant passages as indicated by the broken arrows, whereby the
refrigerant circuit 110 is configured such that the
high-temperature, high-pressure refrigerant flows into the
heat-source-side heat exchanger 1.
[0031] The high-temperature, high-pressure gas refrigerant
discharged from the compressor 3 flows into the heat-source-side
heat exchanger 1 via the refrigerant flow switching device 4. In
the defrosting operation, the heat-source-side heat exchanger 1
operates as a condenser. To be more specific, in the
heat-source-side heat exchanger 1, the condensation heat of the
refrigerant flowing therein is transferred to frost formed on a
surface of the heat-source-side heat exchanger 1. By virtue of this
configuration, the refrigerant flowing in the heat-source-side heat
exchanger 1 condenses and changes into high-pressure liquid
refrigerant. Further, the frost formed on the surface of the
heat-source-side heat exchanger 1 is melted by the heat transferred
from the refrigerant.
[0032] The high-pressure liquid refrigerant condensed at the
heat-source-side heat exchanger 1 passes through the
pressure-reducing device 6, changes into low-pressure, two-phase
refrigerant, then passes through the blocking device 78 being in
the opened state, and flows into the refrigerant flow passage of
the load-side heat exchanger 2. In the defrosting operation, the
load-side heat exchanger 2 operates as an evaporator. That is, in
the load-side heat exchanger 2, heat exchange is performed between
the refrigerant flowing through the refrigerant passage and the
water flowing through the water passage, whereby heat is received
from the water as the evaporation heat of the refrigerant. By
virtue of this configuration, the refrigerant flowing in the
refrigerant passage of the load-side heat exchanger 2 evaporates
and changes into low-pressure gas refrigerant. The gas refrigerant
passes through the blocking device 77 being in the opened state and
the refrigerant flow switching device 4, and is then sucked into
the compressor 3. The refrigerant sucked into the compressor 3 is
compressed and changes into high-temperature, high-pressure gas
refrigerant. In the defrosting operation, the above cycle is
continuously repeated.
[0033] The water circuit 210 will be described. The water circuit
210 of embodiment 1 is a closed circuit which circulates water. In
FIG. 1, the flow directions of the water are indicated by outlined
arrows. The water circuit 210 is configured such that a water
circuit in the outdoor unit 100 and a water circuit in the indoor
unit 200 are connected. The water circuit 210 includes a main
circuit 220, a branch circuit 221 forming a hot-water supply
circuit, and a branch circuit 222 forming part of a heating
circuit. The main circuit 220 forms part of the closed circuit. The
branch circuits 221 and 222 are connected to the main circuit 220
as branches therefrom. The branch circuits 221 and 222 are disposed
in parallel to each other. The branch circuit 221 forms together
with the main circuit 220 a closed circuit. The branch circuit 222
forms together with the main circuit 220, a heating apparatus 300,
etc., a closed circuit. The heating apparatus 300 is connected to
the branch circuit 222. The heating apparatus 300 is provided in
the indoor space, and is located separate from the indoor unit 200.
As the heating apparatus 300, for example, a radiator or a
floor-heating apparatus is used.
[0034] With respect to embodiment 1, although water is described as
an example of a heat medium which flows in the water circuit 210,
another liquid heat medium such as brine can be used as the heat
medium.
[0035] In the main circuit 220, a strainer 56, a flow switch 57,
the load-side heat exchanger 2, a booster heater 54, a pump 53,
etc., are connected by water pipes. At intermediate part of the
water pipes forming the main circuit 220, a drain outlet 62 is
provided to drain water in the water circuit 210. A downstream end
of the main circuit 220 is connected to an inflow port of a
three-way valve 55 (an example of a branching part) including a
single inflow port and two outflow ports. At the three-way valve
55, the branch circuits 221 and 222 branch off from the main
circuit 220. An upstream end of the main circuit 220 is connected
to a joining part 230. At the joining part 230, the branch circuits
221 and 222 join the main circuit 220. Part of the water circuit
210 which extends from the joining part 230 to the three-way valve
55 via the load-side heat exchanger 2, etc., forms the main circuit
220.
[0036] The load-side heat exchanger 2 of the main circuit 220 is
provided in the outdoor unit 100. Devices of the main circuit 220
which are other than the load-side heat exchanger 2 are provided in
the indoor unit 200. That is, the main circuit 220 of the water
circuit 210 is provided to extend between the outdoor unit 100 and
the indoor unit 200. Part of the main circuit 220 is provided in
the outdoor unit 100, and the remaining part of the main circuit
220 is provided in the indoor unit 200. The outdoor unit 100 and
the indoor unit 200 are connected to each other by two connection
pipes 211 and 212 which form part of the main circuit 220.
[0037] The pump 53 is a device which pressurizes the water in the
water circuit 210 to circulate the water in the water circuit 210.
The booster heater 54 is a device which further heats the water in
the water circuit 210, for example, when the heating capacity of
the outdoor unit 100 is insufficient. The three-way valve 55 is a
device which changes the flow of the water in the water circuit
210. For example, the three-way valve 55 switches the flow of the
water in the main circuit 220 between circulation of the water in
the branch circuit 221 and circulation of the water in the branch
circuit 222. The strainer 56 is a device which removes scale in the
water circuit 210. The flow switch 57 is a device which detects
whether the flow rate of the water circulating in the water circuit
210 is higher than or equal to a certain rate. The flow switch 57
can be replaced by a flow-rate sensor.
[0038] The booster heater 54 is connected to a pressure relief
valve 70 (an example of a pressure protection device). That is, the
booster heater 54 serves as connection part of the pressure relief
valve 70, which is connected to the water circuit 210. It should be
noted that the connection part of the pressure relief valve 70 will
be hereinafter occasionally referred to as "connection part". The
pressure relief valve 70 is a protection device which prevents an
excessive increase in pressure in the water circuit 210 which
accompanies a change in temperature of the water. The pressure
relief valve 70 discharges the water to the outside of the water
circuit 210 based on the pressure in the water circuit 210. For
example, if the internal pressure of the water circuit 210
increases to exceed a pressure control range of an expansion tank
52 (to be described later), the pressure relief valve 70 is opened
to discharge the water in the water circuit 210 to the outside of
the water circuit 210 from the pressure relief valve 70. The
pressure relief valve 70 is provided at the indoor unit 200 in
order to effect pressure protection in the water circuit 210 in the
indoor unit 200.
[0039] A housing of the booster heater 54 is connected to one of
ends of a pipe 72 forming a water passage branching off from the
main circuit 220. To the other end of the pipe 72, the pressure
relief valve 70 is attached. That is, the pressure relief valve 70
is connected to the booster heater 54 by the pipe 72. In the main
circuit 220, the temperature of water in the booster heater 54 is
the highest. Therefore, the booster heater 54 is most suitable as
the connection part to which the pressure relief valve 70 is
connected. Further, in the case where the pressure relief valve 70
is connected to the branch circuits 221 and 222, at the branch
circuits 221 and 222, respective pressure relief valves 70 need to
be provided. In embodiment 1, since the pressure relief valve 70 is
connected to the main circuit 220, it suffices to provide a single
pressure relief valve 70.
[0040] At an intermediate part of the pipe 72, a branching part 72a
is provided. The branching part 72a is connected to one of ends of
a pipe 75. The other end of the pipe 75 is connected to the
expansion tank 52. That is, the expansion tank 52 is connected to
the booster heater 54 by the pipes 75 and 72. The expansion tank 52
is a device which controls the change of the internal pressure of
the water circuit 210, which accompanies the change of the
temperature of the water, such that the change of the internal
pressure of the water circuit 21 falls within a certain range.
[0041] The main circuit 220 includes a refrigerant leakage
detecting device 98. The refrigerant leakage detecting device 98 is
connected between the load-side heat exchanger 2 and the booster
heater 54 (the connection part) in the main circuit 220. The
refrigerant leakage detecting device 98 is a device which detects
leakage of refrigerant from the refrigerant circuit 110 into the
water circuit 210. If refrigerant leaks from the refrigerant
circuit 110 into the water circuit 210, the internal pressure of
the water circuit 210 raises. Therefore, the refrigerant leakage
detecting device 98 can detect the leakage of the refrigerant into
the water circuit 210 based on the internal pressure of the water
circuit 210 (the value of the pressure or the variation of the
pressure thereof which is made with the passage of time). As the
refrigerant leakage detecting device 98, for example, a pressure
sensor or a pressure switch (high-pressure switch) which detects
the internal pressure of the water circuit 210 is used. For
example, the pressure switch may adopt an electric system or a
mechanical system using a diaphragm. The refrigerant leakage
detecting device 98 outputs a detection signal to the controller
101.
[0042] In embodiment 1, the blocking devices 77 and 78 and the
refrigerant leakage detecting device 98 are all provided in the
outdoor unit 100. Therefore, the blocking devices 77 and 78 and the
refrigerant leakage detecting device 98 can be connected to the
controller 101 by a control line in the outdoor unit 100, thus
reducing the cost. Furthermore, control of the blocking devices 77
and 78 based on a detection signal from the refrigerant leakage
detecting device 98 (which will be described later) can be achieved
in the outdoor unit 100 solely. Therefore, the versatility of the
outdoor unit 100 is increased, and the flexibility in combination
of the outdoor unit 100 and various indoor units is improved. In a
configuration in which the refrigerant leakage detecting device 98
outputs a contact signal when leakage of refrigerant occurs, the
refrigerant leakage detecting device 98 and the blocking devices 77
and 78 may be directly connected without being connected to the
controller 101.
[0043] The branch circuit 221 forming the hot-water supply circuit
is provided in the indoor unit 200. An upstream end of the branch
circuit 221 is connected to one of the outflow ports of the
three-way valve 55. A downstream end of the branch circuit 221 is
connected to the joining part 230. The branch circuit 221 includes
a coil 61. The coil 61 is located in a hot-water storage tank 51
which stores water therein. The coil 61 is a heating unit which
heats the water stored in the hot-water storage tank 51 through
heat exchange with water (hot water) circulating in the branch
circuit 221 of the water circuit 210. Furthermore, the hot-water
storage tank 51 includes an immersion heater 60 provided therein.
The immersion heater 60 is a heating unit which further heats the
water stored in the hot-water storage tank 51.
[0044] To an upper part of the interior of the hot-water storage
tank 51, a sanitary circuit-side pipe 81a (for example, a hot-water
supply pipe), which is to be connected to, for example, a shower,
is connected. To a lower part of the interior of the hot-water
storage tank 51, a sanitary circuit-side pipe 81b (for example, a
supply water pipe) is connected. At a lower part of the hot-water
storage tank 51, a drain outlet 63 is provided to drain the water
in the hot-water storage tank 51. The hot-water storage tank 51 is
covered by a heat insulating material (not illustrated) to prevent
reduction of the temperature of the water in the hot-water storage
tank 51, which would be caused by heat transfer to the outside of
the hot-water storage tank 51. As the heat insulating material, for
example, felt, Thinsulate (registered trademark), or vacuum
insulation panel (VIP) is applied.
[0045] The branch circuit 222 forming part of the heating circuit
is provided in the indoor unit 200. The branch circuit 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 and an upstream end of the
return pipe 222b are connected to a heating-circuit-side pipe 82a
and a heating-circuit-side pipe 82b, respectively. A downstream end
of the return pipe 222b is connected to the joining part 230.
Thereby, the supply pipe 222a and the return pipe 222b are
connected to the heating apparatus 300 by the heating-circuit-side
pipe 82a and the heating-circuit-side pipe 82b, respectively. The
heating-circuit-side pipes 82a and 82b and the heating apparatus
300 are disposed in the indoor space and outside the indoor unit
200. The branch circuit 222 forms together with the
heating-circuit-side pipes 82a and 82b and the heating apparatus
300, the heating circuit.
[0046] The heating-circuit-side pipe 82a is connected to a pressure
relief valve 301. The pressure relief valve 301 is a protection
device which prevents an excessive increase in the internal
pressure of the water circuit 210, and has the same structure as or
a similar structure to the structure of, for example, the pressure
relief valve 70. For example, if the internal pressure of the
heating-circuit-side pipe 82a exceeds a set pressure, the pressure
relief valve 301 is opened to discharge water in the
heating-circuit-side pipe 82a to the outside of the
heating-circuit-side pipe 82a from the pressure relief valve 301.
The pressure relief valve 301 is provided in the indoor space and
outside the indoor unit 200.
[0047] The heating apparatus 300, the heating-circuit-side pipes
82a and 82b and the pressure relief valve 301 in embodiment 1 are
not part of the heat-pump hot-water supply heating apparatus 1000,
but are equipment to be installed by a technician in the actual
place in accordance with the circumstances of each of properties.
For example, in existing equipment using a boiler as a heat source
apparatus of the heating apparatus 300, there is a case where the
heat source apparatus is updated, that is, it is replaced with the
heat-pump hot-water supply heating apparatus 1000.
[0048] In such a case, the heating apparatus 300, the
heating-circuit-side pipes 82a and 82b, and the pressure relief
valve 301 continue to be used, unless they cause any particular
inconvenience. Therefore, it is preferable that the heat-pump
hot-water supply heating apparatus 1000 be connectable to variable
kinds of equipment regardless of whether the pressure relief valve
301 is provided or not.
[0049] The indoor unit 200 is provided with the controller 201
which performs control mainly of the operation of the water circuit
210 (for example, the pump 53, the booster heater 54 and the
three-way valve 55). The controller 201 includes a microcomputer
provided with a CPU, a ROM, a RAM, an I/O port, etc. The controller
201 can mutually communicate with the controller 101 and the
operation unit 202.
[0050] The operation unit 202 is configured to allow a user to
operate the heat-pump hot-water supply heating apparatus 1000, and
to make various settings. In embodiment 1, the operation unit 202
includes a display unit 203 as a notifying unit which indicates
information. The display unit 203 is capable of displaying various
information such as the state of the heat-pump hot-water supply
heating apparatus 1000. The operation unit 202 is provided at, for
example, a surface of a housing of the indoor unit 200.
[0051] Next, it will be described what operation is performed if
the partition wall isolating the refrigerant passage and the water
passage from each other is broken in the load-side heat exchanger
2. The load-side heat exchanger 2 operates as an evaporator in the
defrosting operation. Therefore, the partition wall of the
load-side heat exchanger 2 may be broken by, for example, freezing
of water which occurs particularly in the defrosting operation. In
general, the pressure of refrigerant flowing in the refrigerant
passage of the load-side heat exchanger 2 is higher than the
pressure of water flowing in the water passage of the load-side
heat exchanger 2 in either the normal operation or the defrosting
operation. Therefore, if the partition wall of the load-side heat
exchanger 2 is broken, the refrigerant in the refrigerant passage
flows out into the water passage and mixes with the water in the
water passage in either the normal operation or the defrosting
operation. At this time, the pressure of the refrigerant mixing
with the water is reduced, and the refrigerant thus gasifies.
Further, since the refrigerant the pressure of which is higher than
that of the water mixes into the water, the internal pressure of
the water circuit 210 is raised.
[0052] The refrigerant mixing with the water of the water circuit
210 in the load-side heat exchanger 2 flows not only in a direction
along the normal flow of water (that is, a direction from the
load-side heat exchanger 2 toward the booster heater 54), but in an
opposite direction to the direction of a normal flow of water (that
is, a direction from the load-side heat exchanger 2 toward the
joining part 230), because of the difference in pressure between
the refrigerant and water. In the case where the main circuit 220
of the water circuit 210 is provided with the pressure relief valve
70 as in embodiment 1, the refrigerant mixing with the water can be
discharged together with the water into the indoor space from the
pressure relief valve 70. Furthermore, in the case where the
heating-circuit-side pipe 82a or 82b is provided with the pressure
relief valve 301 as in embodiment 1, the refrigerant mixing with
the water can be discharged together with the water into the indoor
space from the pressure relief valve 301. That is, the pressure
relief valves 70 and 301 both operate as valves from which the
refrigerant mixing with the water in the water circuit 210 is
discharged to the outside of the water circuit 210. If the
refrigerant has flammability, when the refrigerant is discharged
from the pressure relief valve 70 or 301 into the indoor space,
there is a risk that a flammable concentration region will be
provided in the indoor space.
[0053] In embodiment 1, in the case where leakage of refrigerant to
the water circuit 210 is detected based on a detection signal from
the refrigerant leakage detecting device 98, the controller 101
stops the compressor 3 and causes the blocking devices 77 and 78 to
be set in the closed state. Thereby, the flow of the refrigerant in
the refrigerant circuit 110 is blocked by the blocking devices 77
and 78 at two positions which precedes and succeeds the load-side
heat exchanger 2. That is, with respect to the flow of refrigerant,
the load-side heat exchanger 2 is isolated from the refrigerant
circuit 110. Therefore, the amount of refrigerant leaking to the
water circuit 210 in the load-side heat exchanger 2 can be reduced
to an amount less than or equal to the amount of refrigerant
existing in the load-side heat exchanger 2. Thus, in embodiment 1,
it is possible to reduce leakage of refrigerant into the indoor
space through the pressure relief valves 70 and 301.
[0054] FIG. 2 is a circuit diagram illustrating a schematic
configuration of a heat-pump using apparatus according to a
modification of embodiment 1. As illustrated in FIG. 2, the
configuration of this modification is different from the
configuration as illustrated in FIG. 1 on the point that the
load-side heat exchanger 2 is provided in the indoor unit 200. The
refrigerant circuit 110 is provided to extend between the outdoor
unit 100 and the indoor unit 200. Part of the refrigerant circuit
110 is provided in the outdoor unit 100, and the remaining 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 by two connection pipes 111 and 112 which form part of the
refrigerant circuit 110. Also in this modification, the same
advantages as or similar advantages to those of the configuration
as illustrated in FIG. 1 can be obtained. Furthermore, in the
modification, the blocking devices 77 and 78 and the refrigerant
leakage detecting device 98 are all provided in the indoor unit
200. The refrigerant leakage detecting device 98 outputs a
detection signal to the controller 201, and the blocking devices 77
and 78 are controlled by the controller 201. Thereby, the blocking
devices 77 and 78 and the refrigerant leakage detecting device 98
can be connected to the controller 201 by a control line in the
indoor unit 200. Thus, the cost can be reduced. Furthermore,
control of the blocking devices 77 and 78 based on the detection
signal from the refrigerant leakage detecting device 98 can be
achieved in the indoor unit 200. Therefore, the versatility of the
indoor unit 200 is increased, and the flexibility in combination of
the indoor unit 200 and various outdoor units is improved.
[0055] The position of the refrigerant leakage detecting device 98
provided will be described. FIG. 3 is an explanatory diagram
illustrating examples of the position of the refrigerant leakage
detecting device 98 in the heat-pump using apparatus according to
embodiment 1. FIG. 3 illustrates five positions A to E as examples
of the position of the refrigerant leakage detecting device 98. In
the case where the refrigerant leakage detecting device 98 is
provided at the position A or B, it is connected to the pipe 72.
That is, it is connected to the main circuit 220 by the booster
heater 54 (connection part), as well as the pressure relief valve
70. In such a case, the refrigerant leakage detecting device 98 can
reliably detect leakage of the refrigerant before the refrigerant
leaking into the water circuit 210 in the load-side heat exchanger
2 is discharged from the pressure relief valve 70. When the leakage
of the refrigerant into the water circuit 210 is detected by the
refrigerant leakage detecting device 98, the flow of the
refrigerant in the refrigerant circuit 110 is immediately blocked
by the blocking devices 77 and 78 at two positions which precedes
and succeeds the load-side heat exchanger 2. It is therefore
possible to reduce the amount of refrigerant leaking into the
indoor space from the pressure relief valve 70 to the minimum. The
same advantage as described above or a similar advantage to the
advantage as described above can be also obtained in the case where
the refrigerant leakage detecting device 98 is connected to the
load-side heat exchanger 2 or between the load-side heat exchanger
2 and the booster heater 54 in the main circuit 220.
[0056] In the case where the refrigerant leakage detecting device
98 is provided at the position C or D, it is connected between the
booster heater 54 (connection part) and the three-way valve 55 in
the main circuit 220. In this case, the refrigerant may be
discharged from the pressure relief valve 70 before the refrigerant
leakage detecting device 98 detects the leakage of the refrigerant.
However, as described above, when the leakage of the refrigerant
into the water circuit 210 is detected, the flow of the refrigerant
in the refrigerant circuit 110 is immediately blocked at two
positions which precedes and succeeds the load-side heat exchanger
2. It is therefore possible to reduce the amount of refrigerant
leaking from the pressure relief valve 70 into the indoor space to
the minimum.
[0057] In the case where the refrigerant leakage detecting device
98 is provided at the position E, it is connected between the
load-side heat exchanger 2 and the joining part 230 in the main
circuit 220. In this case, the refrigerant leakage detecting device
98 can reliably detect leakage of the refrigerant before the
refrigerant leaking into the water circuit 210 is discharged from
the pressure relief valve 301 provided outside the indoor unit 200.
When the leakage of the refrigerant into the water circuit 210 is
detected by the refrigerant leakage detecting device 98, the flow
of the refrigerant in the refrigerant circuit 110 is immediately
blocked by the blocking devices 77 and 78 at two positions which
precedes and succeeds the load-side heat exchanger 2. Therefore, it
is possible to reduce the amount of refrigerant leaking from the
pressure relief valve 301 into the indoor space to the minimum.
[0058] In all the configurations as illustrated in FIGS. 1 to 3,
the refrigerant leakage detecting device 98 is connected to the
main circuit 220, not to a branch circuit (for example, the
heating-circuit-side pipes 82a and 82b and the heating apparatus
300) installed by a technician in the actual place. Thus,
attachment of the refrigerant leakage detecting device 98 and
connection between the refrigerant leakage detecting device 98 and
the controller 201 can be carried out by a manufacturer of the
indoor unit 200. It is therefore possible to avoid human errors
such as a failure to attach the refrigerant leakage detecting
device 98 and a failure to connect the refrigerant leakage
detecting device 98 to the controller 201.
[0059] Next, the positions of the blocking devices 77 and 78 will
be described. The blocking devices 77 and 78 are arranged in the
refrigerant circuit 110, with the load-side heat exchanger 2
interposed between the blocking devices 77 and 78. In the
refrigerant circuit 110, the smaller the capacity of a section
which extends from the blocking device 77 to the blocking device 78
through the load-side heat exchanger 2, the smaller the amount of
leakage of refrigerant through the pressure relief valve 70 or the
pressure relief valve 301, that is, the amount of the leakage of
the refrigerant can be further reduced. Therefore, preferably,
devices having a large capacity, such as the compressor 3 and the
heat-source-side heat exchanger 1, should not be provided in the
above section. That is, it is preferable that the blocking device
77 be provided upstream of the load-side heat exchanger 2 and
downstream of the compressor 3 in the flow of refrigerant during
the normal operation. In the case where the refrigerant flow
switching device 4 is provided in the refrigerant circuit 110 as in
embodiment 1, it is preferable that the blocking device 77 be
provided upstream of the load-side heat exchanger 2 and downstream
of the refrigerant flow switching device 4 in the flow of
refrigerant during the normal operation. Furthermore, it is
preferable that the blocking device 78 be provided downstream of
the load-side heat exchanger 2 and upstream of the heat-source-side
heat exchanger 1 in the flow of refrigerant during the normal
operation.
[0060] As described above, the heat-pump hot-water supply heating
apparatus 1000 (an example of a heat-pump using apparatus)
according to embodiment 1 includes the refrigerant circuit 110
which circulates refrigerant, the water circuit 210 (an example of
a heat medium circuit) which allows water (an example of a heat
medium) to flow through the water circuit 210, and the load-side
heat exchanger 2 (an example of a heat exchanger) which causes heat
exchange to be performed between the refrigerant and the water. The
water circuit 210 includes the main circuit 220 which extends
through the load-side heat exchanger 2. The main circuit 220
includes the three-way valve 55 (an example of branching part)
which is provided at a downstream end of the main circuit 220, and
is connected to the plurality of branch circuits 221 and 222 which
branch off from the main circuit 220, and the joining part 230
which is provided at an upstream end of the main circuit 220, and
is connected to the plurality of branch circuits 221 and 222 which
join the main circuit 220. To the main circuit 220, the pressure
relief valve 70 (an example of a pressure protection device 70) and
the refrigerant leakage detecting device 98 are connected. The
pressure relief valve 70 causes water to flow out of the water
circuit 210 based on the internal pressure of the water circuit
210. The refrigerant leakage detecting device 98 detects leakage of
refrigerant from the refrigerant circuit 110 into the water circuit
210. In the refrigerant circuit 110, the blocking device 77 (an
example of a first blocking device) and the blocking device 78 (an
example of a second blocking device) are provided, with the
load-side heat exchanger 2 interposed between the blocking devices
77 and 78.
[0061] In this configuration, even if refrigerant leaks to the
water circuit 210, the flow of the refrigerant in the refrigerant
circuit 110 can be blocked by the blocking devices 77 and 78 at two
positions which precedes and succeeds the load-side heat exchanger.
It is therefore possible to reduce leakage of refrigerant from the
pressure relief valve 70 into indoor space. Furthermore, the
pressure relief valve 301 may be provided in an on-site installed
circuit (for example, the heating-circuit-side pipes 82a and 82b)
that is connected to the water circuit 210 of the indoor unit 200
at a position which precedes the three-way valve 55 or the joining
part 230 as viewed from the main circuit 220 side. In the above
configuration, even if the pressure relief valve 301 is provided in
the on-site installed circuit, it is possible to reduce leakage of
refrigerant from the pressure relief valve 301 into the indoor
space.
[0062] In the heat-pump hot-water supply heating apparatus 1000
according to embodiment 1, the blocking devices 77 and 78 are
opening and closing valves which are closed when leakage of
refrigerant to the water circuit 210 is detected. In this
configuration, if refrigerant leaks to the water circuit 210, the
flow of refrigerant in the refrigerant circuit 110 can be
immediately blocked.
[0063] In the heat-pump hot-water supply heating apparatus 1000
according to embodiment 1, the pressure relief valve 70 is
connected to the booster heater 54 (an example of the connection
part) which is located between the load-side heat exchanger 2 and
one of the three-way valve 55 and the joining part 230 (which is
the three-way valve 55 in this embodiment) in the main circuit 220.
The refrigerant leakage detecting device 98 is connected to the
remaining one of the three-way valve 55 and the joining part 230
(which is the joining part 230 in this embodiment), or between the
above remaining one (the joining part 230 in this embodiment) and
the booster heater 54 (the example of the connection part), or the
booster heater 54 (the example of the connection part). In this
configuration, before refrigerant having leaked to the water
circuit 210 flows into the indoor space, the leakage of the
refrigerant can be reliably detected.
[0064] In the heat-pump hot-water supply heating apparatus 1000
according to embodiment 1, the refrigerant leakage detecting device
98 detects leakage of refrigerant to the water circuit 210 based on
the internal pressure of the water circuit 210. In this
configuration, leakage of refrigerant can be reliably detected.
[0065] In the heat-pump hot-water supply heating apparatus 1000
according to embodiment 1, the blocking device 77 is provided
between the compressor 3 and the load-side heat exchanger 2 in the
refrigerant circuit 110, and the blocking device 78 is provided
between the load-side heat exchanger 2 and the heat-source-side
heat exchanger 1 in the refrigerant circuit 110. That is, in the
flow of refrigerant in the refrigerant circuit 110 during a heating
operation (a normal operation in this embodiment), the blocking
device 77 is located downstream of the compressor 3 and upstream of
the load-side heat exchanger 2, and the blocking device 78 is
located downstream of the load-side heat exchanger 2 and upstream
of the heat-source-side heat exchanger 1. In this configuration,
devices having a large capacity such as the compressor 3 and the
heat-source-side heat exchanger 1 are not located in a section
which extends from the blocking device 77 to the blocking device 78
through the load-side heat exchanger 2. Thus, the amount of leakage
of refrigerant from the pressure relief valve 70 or the pressure
relief valve 301 can be reduced.
[0066] In the heat-pump hot-water supply heating apparatus 1000
according to embodiment 1, the blocking device 78 operates as a
pressure-reducing device in the refrigerant circuit 110. In this
configuration, the number of components in the heat-pump hot-water
supply heating apparatus 1000 can be reduced.
[0067] The heat-pump hot-water supply heating apparatus 1000
according to embodiment 1 further includes the outdoor unit 100
which accommodates the refrigerant circuit 110, part of the water
circuit 210, and the load-side heat exchanger 2, and the indoor
unit 200 which accommodates the remaining part of the water circuit
210. The outdoor unit 100 accommodates the blocking devices 77 and
78 and the refrigerant leakage detecting device 98. In this
configuration, in the outdoor unit 100, the controller 101 can be
connected to each of the blocking devices 77 and 78 and the
refrigerant leakage detecting device 98. Thus, the cost can be
reduced. Furthermore, in this configuration, the versatility of the
outdoor unit 100 can be increased, and the flexibility in
combination of the outdoor unit 100 and various indoor units can be
improved.
[0068] The heat-pump hot-water supply heating apparatus 1000
according to embodiment 1 further includes the outdoor unit 100
which accommodates part of the refrigerant circuit 110 and the
indoor unit 200 which accommodates the remaining part of the
refrigerant circuit 110, the water circuit 210 and the load-side
heat exchanger 2. The indoor unit 200 accommodates the blocking
devices 77 and 78 and the refrigerant leakage detecting device 98.
In this configuration, in the indoor unit 200, the controller 201
can be connected to the blocking devices 77 and 78 and the
refrigerant leakage detecting device 98. Thus, the cost can be
reduced. Furthermore, in this configuration, the versatility of the
indoor unit 200 can be increased, and the flexibility in
combination of the indoor unit 200 and various output units can be
improved.
[0069] In the heat-pump hot-water supply heating apparatus 1000
according to embodiment 1, as the refrigerant, flammable
refrigerant or toxic refrigerant may be used.
Embodiment 2
[0070] A heat-pump using apparatus according to embodiment 2 of the
present invention will be explained. FIG. 4 is a circuit diagram
illustrating a schematic configuration of the heat-pump using
apparatus according to embodiment 2. In FIG. 4, a configuration of
the indoor unit 200 is primarily illustrated. Components which
having the same functions and operations as those in embodiment 1
will be denoted by the same reference signs, and their descriptions
will be omitted. As illustrated in FIG. 4, in embodiment 2, a
boiler circuit 240 which heats water stored in the hot water
storage tank 51 is provided outside the hot water storage tank 51.
The boiler circuit 240 includes a water flow passage which connects
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 which causes heat exchange to be performed
between water flowing in the boiler circuit 240 and water flowing
in the branch circuit 221. When the boiler pump 241 operates, water
in the lower portion of the hot water storage tank 51 flows into
the boiler circuit 240. The water having flowed into the boiler
circuit 240 is heated by heat exchange at the boiler heat exchanger
242, and returns to the upper portion of the hot water storage tank
51. Also in embodiment 2, the same advantages as or similar
advantages to those in embodiment 1 can be obtained.
[0071] The present invention is not limited to the above
embodiments, and various modifications thereof can be made.
[0072] For example, with respect to the above embodiments, the
plate-type heat exchanger is described above as an example of the
load-side heat exchanger 2. However, a heat exchanger other than
the plate-type heat exchanger such as a double-pipe heat exchanger
may be used as the load-side heat exchanger 2 as long as the heat
exchanger causes heat exchange to be performed between refrigerant
and a heat medium.
[0073] Furthermore, with respect to the above embodiments, the
heat-pump hot-water supply heating apparatus 1000 is described
above as an example of a heat-pump using apparatus. However, the
present invention is also applicable to other types of heat-pump
using apparatus such as a chiller.
[0074] Furthermore, with respect to the above embodiments, the
indoor unit 200 provided with the hot water storage tank 51 is
described above as an example. However, the hot water storage tank
may be provided separate from the indoor unit 200.
[0075] The embodiments and modifications described above can be
variously combined when they are put to practical use.
Reference Signs List
[0076] 1 heat-source-side heat exchanger 2 load-side heat exchanger
3 compressor 4 refrigerant flow switching device 6
pressure-reducing device 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
pressure relief valve 72 pipe 72a branching part pipe 77, 78
blocking device 81a, 81b sanitary-circuit-side pipe 82a, 82b
heating-circuit-side pipe 98 refrigerant leakage detecting device
100 outdoor unit 101 controller 102 control line 110 refrigerant
circuit 111, 112 connection pipe 200 indoor unit 201 controller 202
operation unit 203 display unit 210 water circuit 211, 212
connection pipe 220 main circuit 221, 222 branch circuit 222a
supply pipe 222b return pipe 230 joining part 240 boiler circuit
241 boiler pump 242 boiler heat exchanger 300 heating apparatus 301
pressure relief valve 1000 heat-pump hot-water supply heating
apparatus
* * * * *