JPH10238892A - Heat pump hot water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low cost heat pump hot water heater which enables recovering of a liquid refrigerant accumulated a halted heat exchanger at the start with a simple structure. SOLUTION: A refrigerant circuit is made up of a compressor 11, an outdoor heat exchanger 13, first electric expansion valves EV2 and EV3 and room heat exchangers 14 and 15. One end of the hot water supply heat exchanger 15 is connected to the delivery side of the compressor 11 and the other end is connected to one end of a second electric expansion valve EV4. The other end of the second electric expansion valve EV4 is connected to a refrigerant piping 32. A first solenoid valve SV1 is arranged between the delivery side of the compressor 11 and the outdoor heat exchanger 13 while a second solenoid valve SV2 is arranged between the delivery side of the compressor 11 and the hot water supply heat exchanger 15. In the hot water heating operation, the first solenoid valve SV1 is closed by a refrigerant recovery part 5b while the second solenoid valve SV2 is opened and the first electric expansion valves EV2 and EV3 are fully opened while the second electric expansion valve EV4 is opened to a specified travel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heat pump water heater having an air conditioning function and a hot water supply function.

[0002]

2. Description of the Prior Art Conventionally, as a heat pump water heater, as shown in FIG.
Some of them include a cooling water heater 30 and a hot water storage tank unit 40 to perform a cooling / heating operation and a hot water supply operation. The compressor 11 of the outdoor unit 10, the four-way valve 12, the outdoor heat exchanger 13, the electric valve EV1, the electric expansion valve EV2, the indoor heat exchanger 14 of the indoor unit 20, and the capillary tube 18 are connected in a ring to form a refrigerant circuit. Is composed. The compressor 11, the four-way valve 12, the outdoor heat exchanger 13, the electric valve EV1, the electric expansion valve EV3, the indoor heat exchanger 15 of the indoor unit 30, and the capillary tube 18 of the outdoor unit 10 are connected in a ring shape. It constitutes a refrigerant circuit. An electromagnetic valve SV1 is disposed between the compressor 11 and the four-way valve 12 of the refrigerant pipe 31 connecting the compressor 11 and the outdoor heat exchanger 13.

The refrigerant pipe 3 of the outdoor unit 10
2, one end of the capillary tube 43 is connected via check valves 41 and 42 that allow only the flow from the capillary tube 43 side to the refrigerant pipe 32 side. The other end of the capillary tube 43 is connected to one end of the hot water supply heat exchanger 16 having a double pipe structure of the hot water storage tank unit 40. The other end of the hot water supply heat exchanger 16 and the discharge side of the compressor 11 are connected by a refrigerant pipe 34, and an electromagnetic valve S is connected to the refrigerant pipe 34.
V2 is provided. The hot water storage tank unit 40 includes:
The hot water storage tank 17 is provided, and the water in the hot water storage tank 17 is circulated through the hot water supply heat exchanger 16 to boil the hot water. The refrigerant pipe 34 between the hot water supply heat exchanger 16 and the solenoid valve SV2 and the upstream side of the accumulator 18 are connected to the refrigerant pipe 3
5, the solenoid valve SV3 is disposed in the refrigerant pipe 35. The refrigerant pipe 31 and the accumulator 18
Of the solenoid valve SV4 and the flow from the outdoor heat exchanger 13 to the low pressure side of the accumulator 18 only in order from the outdoor heat exchanger 13 to the refrigerant pipe 36. A valve 44 is provided, and the refrigerant pipe 31 between the four-way valve 12 and the solenoid valve SV1 is connected to the upstream side of the accumulator 18 by a refrigerant pipe 37, and the refrigerant pipe 37 is sequentially connected to the refrigerant pipe 37 from the compressor 11 side. The solenoid valve SV5 and the capillary tube 45 are provided.

In the heat pump water heater having the above-described structure, the switching position of the four-way valve 12 cannot be recognized during the hot water supply operation. After operating the valve (not shown), the solenoid valve SV1 is opened, and the main valve of the four-way valve 12 is switched to the switching position indicated by the dotted line by the pressure of the refrigerant discharged from the compressor 11. Thereafter, the solenoid valves SV1 and SV3 are closed, the solenoid valve SV2 is opened, and the electric valve EV1 is fully opened. Then, the refrigerant discharged from the compressor 11 circulates in the order of the hot water supply heat exchanger 16, the capillary tube 43, the check valve 42, the check valve 41, the electric valve EV1, the outdoor heat exchanger 13, and the accumulator 18. The refrigerant is condensed in the hot water supply heat exchanger 16 and the refrigerant is evaporated in the outdoor heat exchanger 13. At this time, the expansion valves EV2 and EV3 are fully closed, and the electric valve SV
5 by opening indoor unit 2
The pressure in the indoor heat exchangers 14, 15 is reduced to low pressure, and the refrigerant in the indoor heat exchangers 14, 15 is recovered via the four-way valve 12, the solenoid valve SV5, and the capillary tube 45.

On the other hand, when the cooling operation and the hot water supply operation are performed simultaneously, the switching position of the four-way valve 12 cannot be recognized as in the case of the hot water supply operation, so that the main valve (not shown) of the four-way valve 12 is changed to the solid line switching position. After the pilot valve (not shown) is operated to open the solenoid valve SV1, the main valve of the four-way valve 12 is switched to the switching position indicated by the dotted line by the pressure of the refrigerant discharged from the compressor 11. Thereafter, the solenoid valves SV1 and SV3 are closed, the solenoid valve SV2 is opened, and the electric expansion valves EV2 and EV2 are closed.
Open V3 fully. Then, the refrigerant discharged from the compressor 11 circulates through the hot water supply heat exchanger 16, the capillary tube 43, the check valve 42, the check valve 41, the electric expansion valve EV2, the indoor heat exchanger 14, and the accumulator 18. , Hot water supply heat exchanger 16, capillary tube 43, check valve 42, check valve 41, electric expansion valve EV3, indoor heat exchanger 14.
And the accumulator 18 is circulated. The refrigerant is condensed in the hot water supply heat exchanger 16 to boil the hot water in the hot water storage tank 17, and the refrigerant is evaporated in the indoor heat exchanger 14 to perform the cooling operation. At this time, the motor-operated valve EV1 is fully closed and the motor-operated valve SV4 is opened to lower the pressure inside the outdoor heat exchanger 13 at rest, and the outdoor heat exchange is performed via the solenoid valve SV4 and the check valve 44. The refrigerant in the vessel 13 is recovered.

[0006]

However, in the above-described heat pump water heater, the solenoid valves SV4, SV5, etc. are used to recover the liquid refrigerant accumulated in the idle heat exchanger at the time of starting the hot water supply operation or the cooling / hot water supply operation. However, there is a disadvantage that the cost is high.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a low-cost heat pump water heater that can recover liquid refrigerant accumulated in a quiescent heat exchanger at the time of startup with a simple configuration.

[0008]

In order to achieve the above object, a heat pump water heater according to claim 1 comprises a compressor, a condenser,
A refrigerant circuit in which the first electric expansion valve and the evaporator are connected in a ring, a hot water supply heat exchanger having one end connected to the discharge side of the compressor, and one end connected to the other end of the hot water supply heat exchanger; ,
A second electric expansion valve having the other end connected to one of the evaporator side and the condenser side of the first electric expansion valve, between a discharge side of the compressor and the condenser; A first solenoid valve disposed, a second solenoid valve disposed between the discharge side of the compressor and the hot water supply heat exchanger, and the first solenoid valve for performing hot water supply operation And a refrigerant recovery unit that opens the second electromagnetic valve, fully opens the first electric expansion valve, and sets the second electric expansion valve to a predetermined opening degree. I have.

According to the heat pump water heater of the first aspect, the first electromagnetic valve is closed, the second electromagnetic valve is opened, and the first electric expansion valve is fully opened by the refrigerant recovery section. Is set to a predetermined opening. The refrigerant discharged from the compressor circulates through the hot water supply heat exchanger, the second electric expansion valve, and the evaporator. At this time, one end of the condenser is closed by the first solenoid valve, but the other end is connected to the second motor-operated expansion valve via the first motor-operated expansion valve which is upstream or fully open of the second motor-operated expansion valve. Since it is connected to the low-pressure side on the upstream side of the expansion valve, a negative pressure is generated in the condenser, and the liquid refrigerant accumulated in the condenser as the idle heat exchanger is evaporated and collected. Therefore, the liquid refrigerant accumulated in the dormant heat exchanger can be recovered at the time of startup with a simple configuration without using an electromagnetic valve or the like separately.

The heat pump water heater according to claim 2 is
In the heat pump water heater according to claim 1, when only the hot water supply operation is performed, the evaporator is an outdoor heat exchanger, and the condenser is an indoor heat exchanger.

According to the heat pump water heater of the second aspect, when only the hot water supply operation is performed, the refrigerant discharged from the compressor is supplied to the outdoor heat source as the hot water supply heat exchanger, the second electric expansion valve, and the evaporator. Circulate the exchanger. At this time, the refrigerant condensed in the hot water supply heat exchanger is reduced in pressure by the second electric expansion valve, and the downstream side of the second electric expansion valve has a low pressure. A negative pressure is generated in the heat exchanger, and the liquid refrigerant accumulated in the indoor heat exchanger is evaporated and collected. Therefore, when performing only the hot water supply operation,
The liquid refrigerant in the indoor heat exchanger, which is a dormant heat exchanger, can be easily recovered.

Further, the heat pump water heater of claim 3 is:
The heat pump water heater according to claim 1, wherein when performing the cooling operation and the hot water supply operation, the evaporator is an indoor heat exchanger, and the condenser is an outdoor heat exchanger.

According to the heat pump water heater of the third aspect, when performing the cooling operation and the hot water supply operation, the refrigerant discharged from the compressor is used as a hot water supply heat exchanger, a second electric expansion valve, and an evaporator. Circulating through the indoor heat exchanger, condensing the refrigerant in the hot water supply heat exchanger to supply hot water, and evaporating the refrigerant in the indoor heat exchanger to perform cooling. At this time, the refrigerant condensed in the hot water supply heat exchanger is reduced in pressure by the second electric expansion valve, and the downstream side of the second electric expansion valve has a low pressure,
A negative pressure is generated in the outdoor heat exchanger that is suspended during the cooling / hot water supply operation, and the liquid refrigerant accumulated in the outdoor heat exchanger is evaporated and collected. Therefore, when performing the cooling operation and the hot water supply operation, the liquid refrigerant in the outdoor heat exchanger, which is the pause heat exchanger, can be easily collected.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a heat pump water heater according to the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 is a circuit diagram of a heat pump water heater according to one embodiment of the present invention. The heat pump water heater includes an outdoor unit 1, indoor units 2, 3, and a hot water storage tank unit 4. The outdoor unit 1 includes a compressor 11, a four-way valve 12 connected to the discharge side of the compressor 11, an outdoor heat exchanger 13 having one end connected to the four-way valve 12, and an outdoor heat exchanger. An electric valve EV1 having one end connected to the other end of the vessel 13. A refrigerant pipe 31 connecting the compressor 11 and the outdoor heat exchanger 13 is also provided.
Between the compressor 11 and the four-way valve 12 of the first solenoid valve SV1
Is arranged. One end of a first electric expansion valve EV2 is connected to the other end of the electric valve EV1 via a closing valve 22, and a first electric expansion valve EV3 is connected to one end of the first electric expansion valve EV2.
Are connected at one end. The other end of the first electric expansion valve EV2 is connected to one end of the indoor heat exchanger 14 of the indoor unit 2, and the other end of the first electric expansion valve EV3 and the indoor heat exchanger 15 of the indoor unit 3 are connected. Connected to one end.
The other ends of the indoor heat exchangers 14 and 15 are connected to the four-way valve 1.
2. The refrigerant pipe 33 is connected to the suction side of the compressor 11 via the accumulator 18, and the closing valve 23 is provided in the refrigerant pipe 33. The compressor 11, the outdoor heat exchanger 1
3. A refrigerant circuit is configured by the electric valve EV1, the first electric expansion valve, the indoor heat exchanger 14, and the accumulator 18,
The refrigerant circuit is constituted by the compressor 11, the outdoor heat exchanger 13, the electric valve EV1, the first electric expansion valve, the indoor heat exchanger 15, and the accumulator 18. The four-way valve 12 has a pilot valve (not shown) and a main valve (not shown) that operates by refrigerant pressure based on the state of the pilot valve.

A second electric expansion valve EV4 is connected to a refrigerant pipe 32 between the closing valve 22 and the first electric expansion valve EV2.
And the other end of the second electric expansion valve EV4 is connected to the hot water supply heat exchanger 16 having a double pipe structure of the hot water storage tank unit 4.
To one end. The other end of the hot water supply heat exchanger 16 and the discharge side of the compressor 11 are connected by a refrigerant pipe 34,
The shutoff valve 24 and the second solenoid valve SV2 are disposed in the refrigerant pipe 34 in this order from the hot water supply heat exchanger 16 side. The refrigerant pipe 3 between the closing valve 24 and the second solenoid valve SV2
4 and the upstream side of the accumulator 18 are connected by a refrigerant pipe 35, and an electromagnetic valve SV3 is disposed in the refrigerant pipe 35. Also, the upper end of the inner pipe 16a of the hot water supply heat exchanger 16 is connected to an intermediate position of the hot water storage tank 17, while the lower end of the inner pipe 16a of the hot water supply heat exchanger 16 is connected to the bottom of the hot water storage tank 17, and a pump 18 is connected. As a result, the water in the hot water storage tank 17 flows from the lower end to the upper end of the inner pipe 16a of the hot water supply heat exchanger 16 and circulates, and heat exchange is performed in the hot water supply heat exchanger 16 to boil the hot water.

The heat pump water heater includes a control device 5 for controlling the compressor 11, the electric valve EV1, and the like. The control device 5 includes a microcomputer, an input / output circuit, and the like. The four-way valve control unit 5a that ensures the operation of the four-way valve 12 at the time of startup, and recovers the liquid refrigerant accumulated in the inactive heat exchanger at the time of startup. And a refrigerant recovery unit 5b.

In the heat pump water heater having the above configuration,
When the operation is turned on to perform the hot water supply operation (shown in FIG. 2A), the main valve (not shown) of the four-way valve 12 is switched by a four-way valve controller 5a of the control device 5 by a dotted line. After operating the pilot valve (not shown) to the position (shown in FIG. 1) (FIG. 2)
(shown in FIG. 2 (c)), the second solenoid valves SV1 and SV2 are opened, the solenoid valve SV3 is closed (shown in FIGS. 2 (d), (e) and (f)), and the electric valve EV1 is fully opened. During the road valve operation guarantee period, the first
Electric expansion valves EV2 and EV3 and the second electric expansion valve E
V4 is opened to a predetermined opening degree (shown in FIGS. 2 (g), (h) and (j)).
When the compressor 11 is started (shown in FIG. 2B), the main valve of the four-way valve 12 is switched to the switching position indicated by the dotted line, that is, the discharge side of the compressor 11 due to the pressure of the refrigerant discharged from the compressor 11. And the indoor heat exchanger 14 side (the outdoor heat exchanger 13 side and the suction side of the compressor 11) is switched to the switching position where it is connected.

After the four-way valve 12 is switched to the switching position indicated by the dotted line, the first solenoid valve SV1 is closed by the refrigerant recovery section 5b of the control device 5, and the first electric expansion is performed during the refrigerant recovery period. Open the valves EV2 and EV3 fully (Fig. 2 (d),
(shown in (j))). During this refrigerant recovery period, the indoor heat exchanger 1 as a condenser of the indoor units 2 and 3 which is stopped during the hot water supply operation
The inside of the indoor heat exchangers 14 and 15 is vaporized and recovered by evaporating the liquid refrigerant in the indoor heat exchangers 14 and 15.

Next, when the refrigerant recovery period ends, the second electric expansion valve EV4 is set to an initial opening larger than a predetermined opening, and the first electric expansion valves EV2 and EV3 are fully closed (FIG. 2).
(h) and (j)). Then, the refrigerant discharged from the compressor 11 is supplied to the hot water supply heat exchanger 16 and the second electric expansion valve EV.
4, the electric valve EV1, the outdoor heat exchanger 13 as an evaporator, and the accumulator 18 circulate in this order, and the hot water supply heat exchanger 1
The refrigerant is condensed in 6, the refrigerant is evaporated in the outdoor heat exchanger 13, and the hot water supply operation is performed using the outdoor as a heat source.

When the operation is turned on for the cooling / hot water supply operation in which hot water is supplied simultaneously with cooling (shown in FIG. 3A), the four-way valve 12 of the control device 5 controls the four-way valve 12. After operating the pilot valve (not shown) so that the main valve (not shown) is in the switching position (shown in FIG. 1) indicated by the solid line (shown in FIG. 3C), the second solenoid valve SV1, Open SV2 and set solenoid valve SV3
Is closed (shown in FIGS. 3 (d), (e) and (f)), and the electric valve EV1 is closed.
Is fully opened, the second electric expansion valve EV4 is opened to a predetermined opening, and the first electric expansion valve EV4 is maintained during the four-way valve operation guarantee period.
2, EV3 is opened to the initial opening (shown in FIGS. 3 (g), (h) and (j)).
Then, when the compressor 11 is started (shown in FIG. 3B), the main valve of the four-way valve 12 is switched to the solid line switching position by the pressure of the refrigerant discharged from the compressor 11, ie, the compressor 11
Is switched to a switching position at which the discharge side of the air conditioner and the outdoor heat exchanger 13 side (the indoor heat exchanger 14 side and the suction side of the compressor 11) are connected.

After the four-way valve 12 is switched to the switching position indicated by the solid line, the first solenoid valve SV1 is closed by the refrigerant recovery section 5b of the control device 5, and the first electric expansion is performed during the refrigerant recovery period. Open the valves EV2 and EV3 fully (Fig. 3 (d),
(shown in (j))). During this refrigerant recovery period, the pressure inside the outdoor heat exchanger 13 as a condenser that is stopped in the cooling / hot water supply operation is set to a low pressure, and the liquid refrigerant in the outdoor heat exchanger 13 is evaporated and collected.

Next, when the refrigerant recovery period ends, the electric valve EV1 is fully closed, the second electric expansion valve EV4 is fully opened, and the first electric expansion valves EV2, EV3 are set to the initial opening degree. (Shown in FIGS. 3 (h) and (j)). Then, the refrigerant discharged from the compressor 11 is supplied to the hot water supply heat exchanger 16, the second
Circulates in the order of the electric expansion valve EV4, the first electric expansion valve EV2, the indoor heat exchanger 14 as an evaporator, and the accumulator 18, and the hot water supply heat exchanger 16, the second electric expansion valve EV4, the first electric motor. The circulation is performed in the order of the expansion valve EV3, the indoor heat exchanger 15, and the accumulator 18. Thus, the refrigerant is condensed in the hot water supply heat exchanger 16 to perform the hot water supply operation, and the refrigerant is evaporated in the outdoor heat exchanger 13 to perform the cooling operation.

When only the cooling operation is performed, the solenoid valves SV1 and SV3 are opened, the second solenoid valve SV2 is closed, and the electric valve EV1 is fully opened, so that the first electric expansion valve EV is opened.
2, EV3 is reduced to a predetermined opening while the second electric expansion valve E
V4 is fully closed. Then, the four-way valve 12 is switched to the position indicated by the solid line, and the refrigerant discharged from the compressor 11 is
Outdoor heat exchanger 13, electric valve EV1, first electric expansion valve EV
2, while circulating in the order of the indoor heat exchanger 14 and the accumulator 18 of the indoor unit 2, the outdoor heat exchanger 13,
Electric valve EV1, first electric expansion valve EV3, indoor unit 3
Circulates in the order of the indoor heat exchanger 15 and the accumulator 18. When performing only the heating operation, the solenoid valve SV
1, SV3 is opened, the second solenoid valve SV2 is closed, the electric valve EV1 is fully opened, and the first electric expansion valve EV is opened.
2, EV3 is reduced to a predetermined opening while the second electric expansion valve E
V4 is fully closed. Then, the four-way valve 12 is switched to the position indicated by the dotted line, and the refrigerant discharged from the compressor 11 is:
The indoor heat exchanger 14, the first electric expansion valve EV2, the electric valve EV1, the outdoor heat exchanger 13, and the accumulator 18 in the indoor unit 2 circulate in this order, and the indoor heat exchanger 15, the first electric motor Expansion valve EV3, electric valve EV
1. Circulate in the order of the outdoor heat exchanger 13 and the accumulator 18.

As described above, in the heat pump water heater having the above configuration, when only the hot water supply operation or the cooling / hot water supply operation is performed, the first solenoid valve SV1 is closed by the refrigerant recovery unit 5b of the control device 5, and The second electromagnetic valve SV2 is opened, the first electric expansion valves EV2 and EV3 are fully opened, and the second
By setting the electric expansion valve EV4 to a predetermined opening degree, the liquid refrigerant accumulated in the inactive heat exchanger can be recovered at the time of start-up with a simple configuration without separately providing an electromagnetic valve or the like. Therefore, a low-cost heat pump water heater can be realized.

When only the hot water supply operation is started, the refrigerant condensed in the hot water supply heat exchanger 16 is reduced in pressure by the second electric expansion valve EV4, and the downstream side of the second electric expansion valve EV4 has a low pressure. Becomes Therefore, a negative pressure is generated in the indoor heat exchangers 14 and 15 as the condensers which are stopped during the hot water supply operation, and the liquid refrigerant accumulated in the indoor heat exchangers 14 and 15 is evaporated and collected, so that the stopped heat The liquid refrigerant in the indoor heat exchanger as the exchanger can be easily collected.

When the cooling / hot water supply operation is started, the refrigerant condensed in the hot water supply heat exchanger 16 is decompressed by the second electric expansion valve EV4, and the downstream side of the second electric expansion valve EV4 is discharged. Low pressure. Therefore, a negative pressure is generated in the outdoor heat exchanger 13 as a condenser which is stopped during the cooling / hot water supply operation, and the liquid refrigerant accumulated in the outdoor heat exchanger 13 is evaporated and collected. Outdoor heat exchanger 1
The liquid refrigerant in 3 can be easily collected.

In the above-described embodiment, the heat pump water heater that performs the cooling and heating operation by switching the four-way valve 12 has been described. However, the four-way valve may be omitted, and either the cooling operation or the heating operation and the hot water supply operation are performed. The present invention may be applied to a heat pump water heater that performs the above.

Further, in the above embodiment, two indoor units 2 and 3 are used, but the number of indoor units is not limited to this and may be one or three or more.

The number of indoor units and the structure of the hot water supply heat exchanger in the heat pump water heater of the present invention are not limited to the above embodiment.

[0031]

As is apparent from the above description, the heat pump water heater according to the first aspect of the present invention comprises a refrigerant circuit in which a compressor, a condenser, a first electric expansion valve, and an evaporator are connected in a ring shape, A hot water supply heat exchanger with one end connected to the discharge side of the machine,
One end is connected to the other end of the hot water supply heat exchanger, and the other end is connected to the first end.
A second electric expansion valve connected to one of the evaporator side and the condenser side of the electric expansion valve, and a first solenoid valve disposed between the discharge side of the compressor and the condenser. And a second solenoid valve disposed between the discharge side of the compressor and the hot water supply heat exchanger. When the hot water supply operation is performed, the refrigerant recovery unit closes the first solenoid valve. The second electromagnetic valve is opened, the first electric expansion valve is fully opened, and the second electric expansion valve is set to a predetermined opening.

Therefore, according to the heat pump water heater of the first aspect of the invention, when the refrigerant discharged from the compressor circulates through the hot water supply heat exchanger, the second electric expansion valve, and the evaporator, one end is connected to the first. The other end of the condenser closed by the solenoid valve is connected to the upstream side of the second electric expansion valve or to the low pressure side upstream of the second electric expansion valve via the fully opened first electric expansion valve. As a result, a negative pressure is generated in the condenser, and the liquid refrigerant accumulated in the condenser as a pause heat exchanger that pauses during the hot water supply operation is evaporated and collected. Therefore, the liquid refrigerant accumulated in the inactive heat exchanger can be recovered at the time of startup with a simple configuration without using an electromagnetic valve or the like separately.

The heat pump water heater according to the second aspect of the present invention is the heat pump water heater according to the first aspect, wherein when only the hot water supply operation is performed, the evaporator is an outdoor heat exchanger.
Since the condenser is an indoor heat exchanger, the refrigerant condensed in the hot water supply heat exchanger is depressurized by the second electric expansion valve, and a negative pressure is generated in the indoor heat exchanger as the condenser, and the hot water supply operation is performed. The liquid refrigerant accumulated in the indoor heat exchanger that is suspended inside is evaporated and collected. Therefore, when only the hot water supply operation is performed, the liquid refrigerant in the indoor heat exchanger, which is the dormant heat exchanger, can be easily collected.

In the heat pump water heater according to the third aspect of the present invention, when performing the cooling operation and the hot water supply operation in the heat pump water heater of the first aspect, the evaporator is an indoor heat exchanger, and the condenser is Since it is an outdoor heat exchanger, the refrigerant condensed in the hot water supply heat exchanger is depressurized by the second electric expansion valve, and the downstream side of the second electric expansion valve is set to a low pressure. A negative pressure is generated in the inside, and the liquid refrigerant accumulated in the outdoor heat exchanger which is stopped during the cooling / hot water supply operation is evaporated and collected. Therefore, when performing the cooling operation and the hot water supply operation, it is possible to easily recover the liquid refrigerant in the outdoor heat exchanger that is the pause heat exchanger.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a heat pump water heater according to one embodiment of the present invention.

FIG. 2 is a timing chart when only the hot water supply operation of the heat pump water heater is started.

FIG. 3 is a timing chart when the cooling / hot water supply operation of the heat pump water heater is started.

FIG. 4 is a circuit diagram of a conventional heat pump water heater.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Outdoor unit, 2, 3 ... Indoor unit, 4 ... Hot water storage tank unit, 5 ... Control device, 5a ... Four way valve control part, 5b
... refrigerant recovery unit, 11 ... compressor, 12 ... four-way valve, 13 ... outdoor heat exchanger, 14,15 ... indoor heat exchanger, 16 ... hot water supply heat exchanger, 17 ... hot water storage tank, 18 ... accumulator, 1
9 pump, 22, 23, 24 closing valve, SV1 first solenoid valve, SV2 second solenoid valve, SV3 solenoid valve, EV
1: electric valve, EV2, EV3: first electric expansion valve, EV
4: Second electric expansion valve.

Claims (3)

[Claims] 1. A compressor (11), a condenser, and a first electric expansion valve.
A refrigerant circuit in which the (EV2, EV3) and the evaporator are connected in a ring; a hot water supply heat exchanger (15) having one end connected to the discharge side of the compressor (11); and a hot water supply heat exchanger (15) One end is connected to the other end, and the other end is connected to either the evaporator side or the condenser side of the first electric expansion valve (EV2, EV3).
An electric expansion valve (EV4), a first solenoid valve (SV1) disposed on a refrigerant pipe (31) between the discharge side of the compressor (11) and the condenser, and a compressor ( 11) and a second solenoid valve (SV) disposed in a refrigerant pipe (34) between the hot water supply heat exchanger (15) and the hot water supply heat exchanger (15).
2) When performing the hot water supply operation, the first solenoid valve (SV1) is closed, the second solenoid valve (SV2) is opened, and the first electric expansion valves (EV2, EV3) are fully opened. And a refrigerant recovery unit for setting the second electric expansion valve (EV4) to a predetermined opening degree.
(5b) A heat pump water heater comprising: 2. The heat pump water heater according to claim 1, wherein when performing only the hot water supply operation, the evaporator is an outdoor heat exchanger.
(13), wherein the condenser is an indoor heat exchanger (14, 15).
A heat pump water heater characterized in that: 3. The heat pump water heater according to claim 1, wherein when performing the cooling operation and the hot water supply operation, the evaporator is an indoor heat exchanger (14, 15), and the condenser is an outdoor heat exchanger.
(13) A heat pump water heater characterized in that: