EP4679001A1

EP4679001A1 - Heat pump unit

Info

Publication number: EP4679001A1
Application number: EP23927323.8A
Authority: EP
Inventors: Takashi TAMBA; Hideho SAKAGUCHI; Maxim VERMEERSCH; Joris Brysse
Original assignee: Daikin Europe NV; Daikin Industries Ltd
Current assignee: Daikin Europe NV; Daikin Industries Ltd
Priority date: 2023-03-10
Filing date: 2023-03-10
Publication date: 2026-01-14
Also published as: EP4679001A4; WO2024189699A1

Abstract

Provided is a heat pump unit that achieves a space-saving arrangement of an accumulator and a liquid gas heat exchanger. In a heat pump unit 100, a liquid gas heat exchanger 21 and an accumulator 23 are disposed vertically with the accumulator 23 disposed above. A suction pipe 92 coming from a side of the liquid gas heat exchanger 21 is guided directly above a head of the accumulator 23. This configuration facilitates routing of the suction pipe 92 and saves space.

Description

TECHNICAL FIELD

The present disclosure relates to a heat pump unit.

BACKGROUND ART

As a heat pump unit equipped with a liquid gas heat exchanger, for example, Patent Literature 1 ( JP H10-19407 A ) discloses a heat pump unit in which a liquid gas heat exchanger is provided in an accumulator.

SUMMARY OF THE INVENTION

However, a configuration in which the accumulator and the liquid gas heat exchanger are independently connected to a heat pump unit is not mentioned in the above patent literature. Therefore, a heat pump unit that achieves space-saving arrangement of the accumulator and the liquid gas heat exchanger is desired.

A heat pump unit according to a first aspect is a heat pump unit that circulates a refrigerant through a refrigerant circuit in which a compressor, a radiator, a decompressor, and an evaporator are annularly connected, and includes a liquid gas heat exchanger, an accumulator, and a casing. The liquid gas heat exchanger causes heat exchange between a high-pressure refrigerant having exited a refrigerant outlet of the radiator and a low-pressure refrigerant from a refrigerant outlet of the evaporator to a suction port of the compressor. The accumulator is connected to a middle of a suction pipe connecting the suction port of the compressor and the liquid gas heat exchanger, and is disposed above the liquid gas heat exchanger. The casing accommodates at least the compressor, the liquid gas heat exchanger, and the accumulator.
In the heat pump unit, the liquid gas heat exchanger and the accumulator are disposed vertically with the accumulator disposed above, which saves space.
A heat pump unit according to a second aspect is the heat pump unit according to the first aspect and further includes a mounting plate including a support that supports the accumulator.
In this heat pump unit, vibration of the accumulator caused by an operation of the compressor can be absorbed by the support of the mounting plate.
A heat pump unit according to a third aspect is the heat pump unit according to the second aspect, in which the support is located between the liquid gas heat exchanger and the accumulator.
A heat pump unit according to a fourth aspect is the heat pump unit according to the second or third aspect, in which a bottom of the casing has a double structure including a first bottom plate and a second bottom plate located below the first bottom plate.
In this heat pump unit, vibration propagating to the first bottom plate is attenuated between the first bottom plate and the second bottom plate to enhance vibration-proof performance.
A heat pump unit according to a fifth aspect is the heat pump unit according to the fourth aspect, in which the bottom of the casing further includes a vibration-proof member between the first bottom plate and the second bottom plate.
In this heat pump unit, the vibration propagating to the first bottom plate is further attenuated by the vibration-proof member between the first bottom plate and the second bottom plate to further enhance the vibration-proof performance.
A heat pump unit according to a sixth aspect is the heat pump unit according to the fourth or fifth aspect, in which the mounting plate is installed on the first bottom plate.
In this heat pump unit, the vibration of the accumulator is attenuated by the support of the mounting plate, then propagated to the first bottom plate via the mounting plate, and further attenuated by the first bottom plate.
A heat pump unit according to a seventh aspect is the heat pump unit according to any one of the fourth to sixth aspects, in which the liquid gas heat exchanger is disposed between the first bottom plate and the support of the mounting plate.
In this heat pump unit, the liquid gas heat exchanger, the mounting plate, and the accumulator can be collectively disposed on the first bottom plate, which saves space.
A heat pump unit according to an eighth aspect is the heat pump unit according to any one of the fourth to seventh aspects, in which a shortest distance from the first bottom plate to the support of the mounting plate is 1.1 times to 2.0 times a height dimension of the liquid gas heat exchanger.
A heat pump unit according to a ninth aspect is the heat pump unit according to any one of the first to eighth aspects, in which a suction pipe connecting the liquid gas heat exchanger and the accumulator is guided from a side of the liquid gas heat exchanger to a head of the accumulator.
In this heat pump unit, since the liquid gas heat exchanger and the accumulator are disposed vertically with the accumulator disposed above, the pipe coming from the liquid gas heat exchanger can be guided directly above the head of the accumulator, the pipe can be easily routed, and space saving is achieved.
A heat pump unit according to a tenth aspect is the heat pump unit according to any one of the first to ninth aspects, and further includes a gas liquid separator accommodated in the casing together with the radiator. The radiator is a water heat exchanger, and the gas liquid separator is installed in a water pipe connected to the radiator.
In this heat pump unit, since the degree of integration of the plurality of devices in the casing is increased, an increase in size of the heat pump unit is suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an external perspective view of a heat pump unit according to an embodiment of the present disclosure.
FIG. 2 is a plan view of the inside of the heat pump unit in FIG. 1.
FIG. 3 is a refrigerant circuit diagram of a heat pump unit according to an embodiment of the present disclosure.
FIG. 4 is a perspective view of the inside of a machine chamber.
FIG. 5 is a perspective view of the machine chamber from which a mounting plate and parts and pipes around an accumulator are removed.

DESCRIPTION OF EMBODIMENTS

(1) Configuration of heat pump unit 100

FIG. 1 is an external perspective view of a heat pump unit 100 according to an embodiment of the present disclosure. In FIG. 1, a front surface of a casing 80 is intentionally removed to reveal a fan 29.
In FIG. 1, the heat pump unit 100 is utilized in a household hot water supply system. However, the heat pump unit 100 can be applied to many other applications.
FIG. 2 is a plan view of the inside of the heat pump unit 100 in FIG. 1. In FIG. 2, most of components of the heat pump unit 100 are accommodated in the casing 80.
The inside of the casing 80 is partitioned by a partition plate 87 into a machine chamber 88 on the right side and a fan chamber 89 on the left side in plan view of FIG. 2.
FIG. 3 is a refrigerant circuit diagram of the heat pump unit 100. In FIGS. 2 and 3, the machine chamber 88 accommodates a compressor 11, an accumulator 23, and the like constituting a part of a refrigerant circuit 90. A first heat exchanger 15 constituting a part of the refrigerant circuit 90 and the fan 29 which blows air to a first heat exchanger 15 are accommodated in the fan chamber 89.
In FIG. 3, in the refrigerant circuit 90, the compressor 11, the first heat exchanger 15, a decompression valve 17, and a second heat exchanger 19 are annularly connected.
The heat pump unit 100 circulates a refrigerant in the refrigerant circuit 90 to transfer thermal energy between the first heat exchanger 15 and the second heat exchanger 19. The refrigerant is preferably a hydrocarbon such as R290, which has both low ozone depletion potential and low global warming potential.
The refrigerant circuit 90 further includes a four-way switching valve 13, a liquid gas heat exchanger 21, accumulator 23, a gas injection valve 25, an economizer heat exchanger 27, and a gas liquid separator 31.

(1-1) Compressor 11

The compressor 11 has a suction port 11a, an injection port 11b, and a discharge port 11c. The refrigerant flows into the compressor 11 through the suction port 11a, is compressed to a high temperature and high pressure, and flows out of the discharge port 11c.
The refrigerant can flow into the compressor 11 through the injection port 11b which is in the middle of a compression process.

(1-2) Four-way switching valve 13

During a cooling operation, the four-way switching valve 13 connects the discharge port 11c of the compressor 11 and the first heat exchanger 15, and connects the suction port 11a of the compressor 11 and the second heat exchanger 19. During a heating operation, the four-way switching valve 13 connects the discharge port 11c of the compressor 11 and the second heat exchanger 19, and connects the suction port 11a of the compressor 11 and the first heat exchanger 15.
The four-way switching valve 13 reverses the flow of the refrigerant to cause the second heat exchanger 19 to function as an evaporator and the first heat exchanger 15 to function as a radiator during the cooling operation. During the heating operation, the four-way switching valve 13 causes the second heat exchanger 19 to function as a radiator and the first heat exchanger 15 to function as an evaporator.

(1-3) First heat exchanger 15

The first heat exchanger 15 is an air heat exchanger. The first heat exchanger 15 causes heat exchange between the refrigerant flowing inside and outside air sent from the fan 29. As the first heat exchanger 15, a heat exchanger suitable for the application, such as a fin and tube heat exchanger and a microchannel heat exchanger, is adopted.

(1-4) Decompression valve 17

The decompression valve 17 is an electric expansion valve. A liquid refrigerant flowing through the decompression valve 17 expands into a gas liquid mixed refrigerant to lower the pressure and temperature of the refrigerant. The decompression valve 17 controls a flow rate of the refrigerant passing through the decompression valve by adjusting a valve opening degree.

(1-5) Second heat exchanger 19

The second heat exchanger 19 is a water heat exchanger. In the present embodiment, the second heat exchanger 19 causes heat exchange between the refrigerant flowing inside and water of the household hot water supply system. As the second heat exchanger 19, a heat exchanger suitable for the application, such as a plate heat exchanger, is adopted.

(1-6) Liquid gas heat exchanger 21

The liquid gas heat exchanger 21 causes heat exchange between a high-pressure refrigerant that has exited through a refrigerant outlet of the second heat exchanger 19 and a low-pressure refrigerant that has exited through a refrigerant outlet of the first heat exchanger 15 toward the suction port of the compressor 11.

(1-7) Accumulator 23

The accumulator 23 is connected between the four-way switching valve 13 and the suction port 11a of the compressor 11. The accumulator 23 collects the liquid refrigerant that has not been gasified in the evaporator, and prevents the liquid refrigerant from flowing into the suction port 11a of the compressor 11.

(1-8) Gas injection valve 25

The gas injection valve 25 is, for example, an on-off valve such as a solenoid valve, or a flow rate control valve such as an electrically powered expansion valve. In the present embodiment, the gas injection valve 25 is an electrically powered expansion valve.

(1-9) Economizer heat exchanger 27

The economizer heat exchanger 27 is configured to cause exchange heat between a high-temperature liquid refrigerant flowing out of the second heat exchanger 19, and a gas liquid mixed refrigerant flowing out of the gas injection valve 25. As a result, the liquid refrigerant from the second heat exchanger 19 is subcooled.
An electromagnetic valve 33 is connected between a refrigerant flow path 91 and the economizer heat exchanger 27.

(1-10) Gas liquid separator 31

The gas liquid separator 31 separates the refrigerant mixed in a water pipe 96 connected to the second heat exchanger 19. The gas liquid separator 31 is installed on a water outlet side of the second heat exchanger 19.

(1-11) Control unit 40

A control unit 40 controls an operating frequency of the compressor 11, monitors a discharge temperature of the compressor 11, controls switching of the four-way switching valve 13, controls the opening degree of the decompression valve 17, controls an operation of the gas injection valve 25, and controls opening and closing of the electromagnetic valve 33.
The control unit 40 includes a printed circuit board equipped with a microprocessor and a memory. The control unit 40 is disposed in an upper portion of the fan chamber 89 while being accommodated in an electric component box 70.

(2) Operation of heat pump unit 100

Here, the operation of the heat pump unit 100 during the heating operation will be described. A broken-line arrow in FIG. 3 indicates the flow of the refrigerant in the refrigerant circuit 90 during the heating operation.
During the heating operation, the four-way switching valve 13 switches a flow path as indicated by a dotted line in FIG. 3, and the control unit 40 circulates the refrigerant through the compressor 11, the second heat exchanger 19, the decompression valve 17, and the first heat exchanger 15 in that order.
The refrigerant compressed to high temperature and high pressure by the compressor 11 becomes a high-temperature gas refrigerant, flows out of the discharge port 11c, and flows into the second heat exchanger 19. In the second heat exchanger 19, the high-temperature gas refrigerant heats the water in the household hot water supply equipment, and the refrigerant is liquefied.
The control unit 40 monitors the temperature of the refrigerant exiting through the discharge port 11c of the compressor 11 via a temperature sensor 50. If the temperature exceeds a predetermined value, the control unit 40 opens the gas injection valve 25.
The liquid refrigerant that has flowed out of the second heat exchanger 19 flows toward the economizer heat exchanger 27 and flows into a first flow path 27a of the economizer heat exchanger 27. The refrigerant that has flowed into the first flow path 27a partially branches off to a second flow path 27b heading for the gas injection valve 25, while the remainder branches off to a liquid refrigerant flow path 21b of the liquid gas heat exchanger 21. The refrigerant that has flowed into the second flow path 27b is decompressed when passing through the gas injection valve 25, becomes a low-temperature gas liquid mixed refrigerant, and flows into the economizer heat exchanger 27.
In the economizer heat exchanger 27, the gas liquid mixed refrigerant from the gas injection valve 25 exchanges heat with the high-temperature liquid refrigerant flowing through the first flow path 27a. As a result, the gas liquid mixed refrigerant is heated to become a nearly saturated gas refrigerant, while the liquid refrigerant flowing through the first flow path 27a is subcooled.
The gas refrigerant that has flowed out of the economizer heat exchanger 27 flows into the injection port 11b of the compressor 11. The injection port 11b of the compressor 11 is located in the middle of a compression stage of the compressor 11. Therefore, the gas refrigerant flowing in through the injection port 11b will enter where the refrigerant from the suction port 11a has already been partially compressed.
The refrigerant flowing through the liquid refrigerant flow path 21b of the liquid gas heat exchanger 21 heads for the decompression valve 17. The refrigerant that has flowed into the decompression valve 17 expands in the decompression valve 17 and becomes a low-temperature gas liquid mixed refrigerant. The gas liquid mixed refrigerant flows into the first heat exchanger 15 and evaporates in the first heat exchanger 15.
The refrigerant that has flowed out of the first heat exchanger 15 flows through the gas refrigerant flow path 21a of the liquid gas heat exchanger 21 and heads for the accumulator 23. The refrigerant that has flowed into the accumulator 23 has an excess liquid component collected in the accumulator 23.
In the liquid gas heat exchanger 21, heat is exchanged between the liquid refrigerant heading for the decompression valve 17 and the gas refrigerant that has flowed out of the first heat exchanger 15, whereby the refrigerant heading for the decompression valve 17 is subcooled.
The gas refrigerant that has flowed out of the accumulator 23 returns to the suction port 11a of the compressor 11. Thereafter, the gas refrigerant is compressed to high temperature and high pressure by the compressor 11.

(3) Arrangement of parts in machine chamber 88

FIG. 4 is a perspective view of the inside of the machine chamber 88. In FIG. 4, a bottom 86 of the casing 80 has a double structure including a first bottom plate 861 and a second bottom plate 862 located below the first bottom plate 861.
A vibration-proof member 863 is disposed between the first bottom plate 861 and the second bottom plate 862. The compressor 11 which is heavy and configured to vibrate is mounted on the bottom 86 of the casing 80, particularly to the bottom 86 close to the machine chamber 88. The vibration propagating from the compressor 11 to the first bottom plate 861 is attenuated by the vibration-proof member 863 between the first bottom plate 861 and the second bottom plate 862. Therefore, the vibration-proof property is high.
The second heat exchanger 19 and the liquid gas heat exchanger 21 are further mounted on the bottom 86 in the machine chamber 88. The second heat exchanger 19 is disposed adjacent to the compressor 11, and is usually susceptible to vibration of the compressor 11, but is hardly affected because the bottom 86 has a double structure.

(3-1) Arrangement of liquid gas heat exchanger 21 and accumulator 23

The liquid gas heat exchanger 21 is not heavy like the compressor 11, but is connected to the accumulator 23 by the suction pipe 92, and an occupied space between the liquid gas heat exchanger 21 and the accumulator 23 may increase depending on routing of a pipe.
Therefore, in the present embodiment, the liquid gas heat exchanger 21 is mounted on the bottom 86, and the accumulator 23 is disposed above the liquid gas heat exchanger 21. The accumulator 23 is desirably disposed directly above the liquid gas heat exchanger 21.
The suction pipe 92 connecting the liquid gas heat exchanger 21 and the accumulator 23 extends from a side surface of the liquid gas heat exchanger 21 and is connected to a head of the accumulator 23 (see FIG. 5). If the liquid gas heat exchanger 21 is disposed above the accumulator 23, a space for facilitating the work of routing the suction pipe 92 to the head of the accumulator 23 is to be secured. Therefore, the space between the head of the accumulator 23 and the liquid gas heat exchanger 21 is enlarged, and a dead space is increased.
Therefore, when the accumulator 23 is disposed above the liquid gas heat exchanger 21, routing of the suction pipe 92 is facilitated, and space saving is achieved. From the viewpoint that a diameter of the suction pipe 92 is larger than a diameter of the other pipes, the suction pipe 92 can be easily routed when the suction pipe and the other pipes are disposed close to each other in the vertical direction.

(3-2) Mounting plate 22

The accumulator 23, which is heavy and accumulates the liquid refrigerant, cannot be held only by the pipe. Therefore, the accumulator 23 is mounted above the liquid gas heat exchanger 21 by a mounting plate 22.
FIG. 5 is a perspective view of the machine chamber 88 from which the mounting plate 22 and parts and pipes around the accumulator 23 are removed. In FIG. 2, the mounting plate 22 includes a support 221, a first vertical plate 222, and a second vertical plate 223.

(3-2-1) Support 221

The support 221 is located between the liquid gas heat exchanger 21 and the accumulator 23, and supports a bottom of the accumulator 23. The support 221 supports the bottom of the accumulator 23 at end surfaces of two upward protruding plates 221b standing vertically upward from a horizontal plate 221a. A downward protruding plate 221c which protrudes vertically downward from an end of the horizontal plate 221a is provided.

(3-2-2) First vertical plate 222

The first vertical plate 222 is a plate extending vertically downward from an end of the support 221 opposite to the end where the downward protruding plate 221c is located. The horizontal plate 221a of the support 221 and the first vertical plate 222 are integrally molded. A lower end of the first vertical plate 222 is fixed to the first bottom plate 861.

(3-2-3) Second vertical plate 223

The second vertical plate 223 is a plate extending vertically downward while being connected to the downward protruding plate 221c of the support 221. The second vertical plate 223 is fixed to the first bottom plate 861.
As illustrated in FIG. 5, the liquid gas heat exchanger 21 is disposed between the first vertical plate 222 and the second vertical plate 223, and the support 221 that supports the bottom of the accumulator 23 is located directly above the liquid gas heat exchanger 21.
The dimensions of the first vertical plate 222 and the second vertical plate 223 are set such that the shortest distance from the first bottom plate 861 to the support 221 is 1.1 times to 2.0 times the height dimension of the liquid gas heat exchanger 21. In the present embodiment, the shortest distance from the first bottom plate 861 to the support 221 is 326 mm, and the height dimension of the liquid gas heat exchanger 21 is 209 mm.
When the heat pump unit 100 is in operation, the vibration of the compressor 11 vibrates the accumulator 23, and the vibration propagates from the support 221 to the first bottom plate 861 through the first vertical plate 222 and the second vertical plate 223.
Therefore, the vibration of the accumulator 23 is prevented from propagating to the liquid gas heat exchanger 21 via the pipe.
As illustrated in FIG. 5, the second vertical plate 223 includes a pipe holder 223a extending in the direction of the partition plate 87. The pipe holder 223a holds the economizer heat exchanger 27. The economizer heat exchanger 27 is not directly held by the pipe holder 223a, but is held via a fixture 271.

(4) Characteristics

(4-1)
In the heat pump unit 100, the liquid gas heat exchanger 21 and the accumulator 23 are disposed vertically with the accumulator 23 disposed above, which saves space.
(4-2)
The heat pump unit 100 includes the mounting plate 22 including the support 221 which supports the accumulator 23. The support 221 is located between the liquid gas heat exchanger 21 and the accumulator 23. The support 221 absorbs the vibration of the accumulator 23 caused by the operation of the compressor 11.
(4-3)
In the heat pump unit 100, the bottom 86 of the casing 80 has a double structure including the first bottom plate 861 and the second bottom plate 862 located below the first bottom plate 861, and the vibration-proof member 863 is provided between the first bottom plate 861 and the second bottom plate 862. The vibration propagated to the first bottom plate 861 is attenuated by the double structure of the first bottom plate 861 and the second bottom plate 862, and is further attenuated by the vibration-proof member 863 between the first bottom plate 861 and the second bottom plate 862 to further enhance the vibration-proof property.
(4-4)
The mounting plate 22 is installed on the first bottom plate 861, and the vibration of the accumulator 23 is attenuated by the support 221 of the mounting plate 22, then propagated to the first bottom plate 861 via the first vertical plate 222 and the second vertical plate 223 of the mounting plate 22, and further attenuated by the first bottom plate 861.
(4-5)
Since the liquid gas heat exchanger 21 is disposed between the first bottom plate 861 and the support 221 of the mounting plate 22, the liquid gas heat exchanger 21, the mounting plate 22, and the accumulator 23 can be collectively disposed on the first bottom plate 861, which saves space.

The shortest distance from the first bottom plate 861 to the support 221 of the mounting plate 22 is 1.1 times to 2.0 times the height dimension of the liquid gas heat exchanger 21.

(4-6)
In the heat pump unit 100, since the liquid gas heat exchanger 21 and the accumulator 23 are disposed vertically with the accumulator 23 disposed above, the suction pipe 92 coming from a side of the liquid gas heat exchanger 21 can be guided directly above the head of the accumulator 23, the suction pipe 92 can be easily routed, and space saving is achieved.
(4-7)
In the heat pump unit 100, the gas liquid separator 31 and the second heat exchanger 19 as a water heat exchanger are also accommodated in the casing 80. Since the degree of integration of the plurality of devices in the casing 80 is increased, an increase in size of the heat pump unit 100 is suppressed.

The embodiment of the present disclosure has been described above. It will be understood that various modifications to modes and details should be available without departing from the gist and the scope of the present disclosure recited in the claims.

REFERENCE SIGNS LIST

11: compressor
15: first exchanger (radiator, evaporator)
17: decompression valve (decompression mechanism)
19: second heat exchanger (evaporator, radiator)
21: liquid gas heat exchanger
22: mounting plate
23: accumulator
31: gas liquid separator
80: casing
86: bottom
100: heat pump unit (heat source unit)
221: support
861: first bottom plate
862: second bottom plate
863: vibration-proof member

CITATION LIST

PATENT LITERATURE

Patent Literature 1: JP H10-19407 A

Claims

A heat pump unit (100) that circulates a refrigerant through a refrigerant circuit in which a compressor (11), a radiator, a decompressor (17), and an evaporator are annularly connected, the heat pump unit comprising:
a liquid gas heat exchanger (21) that causes heat exchange between a high-pressure refrigerant having exited a refrigerant outlet of the radiator and a low-pressure refrigerant from a refrigerant outlet of the evaporator to a suction port of the compressor (11);

an accumulator (23) that is connected to a middle of a suction pipe connecting the suction port of the compressor (11) and the liquid gas heat exchanger (21) and is disposed above the liquid gas heat exchanger (21); and

a casing (80) that accommodates at least the compressor (11), the liquid gas heat exchanger (21), and the accumulator (23).
The heat pump unit (100) according to claim 1, further comprising a mounting plate (22) including a support (221) that supports the accumulator (23).
The heat pump unit (100) according to claim 2, wherein
the support (221) is located between the liquid gas heat exchanger (21) and the accumulator (23).
The heat pump unit (100) according to claim 2 or 3, wherein
a bottom (86) of the casing (80) has a double structure including a first bottom plate (861) and a second bottom plate (862) located below the first bottom plate (861).
The heat pump unit (100) according to claim 4, wherein
the bottom (86) of the casing (80) further includes a vibration-proof member (863) between the first bottom plate (861) and the second bottom plate (862).
The heat pump unit (100) according to claim 4 or 5, wherein
the mounting plate (22) is installed on the first bottom plate (861).
The heat pump unit (100) according to any one of claims 4 to 6, wherein
the liquid gas heat exchanger (21) is disposed between the first bottom plate (861) and the support (221) of the mounting plate (22).
The heat pump unit (100) according to any one of claims 4 to 7, wherein
a shortest distance from the first bottom plate (861) to the support (221) of the mounting plate (22) is 1.1 times to 2.0 times a height dimension of the liquid gas heat exchanger (21).
The heat pump unit (100) according to any one of claims 1 to 8, wherein
the suction pipe connecting the liquid gas heat exchanger (21) and the accumulator (23) is guided to a head of the accumulator (23) from a side of the liquid gas heat exchanger (21).
The heat pump unit (100) according to any one of claims 1 to 9, further comprising
a gas liquid separator (31) accommodated in the casing (80) together with the radiator, wherein

the radiator is a water heat exchanger, and the gas liquid separator (31) is installed in a water pipe connected to the radiator.