JPH10220893A - Heat pump device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger, capable of supercooling refrigerant upon cooling operation and absorbing the heat of outside air by evaporating the refrigerant upon heating operation, and improve heating capacity, in a heat pump device, circulating the refrigerant by a compressor and capable of switching the cooling operation into the heating operation. SOLUTION: A heat pump device is provided with three pieces of U-shape refrigerant flow passages 92-94 for a heat exchanger 9 while the refrigerant flow passages 92-94 can be switched by a valve means, consisting of solenoid valves 7b-7i and check valves 10a-10f, so as to be connected in series upon cooling operation and in parallel upon heating operation. Further, the device is provided with a distributor 91, distributing refrigerant, whose pressure is reduced by an expansion valve 11a for heating, into respective refrigerant flow passages 92-94 simultaneously, and a header 90, into which the refrigerant, discharged out of respective refrigerant flow passages 92-94, is collected, upon the heating operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pump apparatus capable of switching between cooling and heating in which a refrigerant is circulated in a compressor.

[0002]

2. Description of the Related Art As a prior art of this type of heat pump device, there is a means for improving a cooling capacity by guiding a liquid refrigerant at an outlet of an outdoor heat exchanger serving as a condenser to a supercooling heat exchanger during cooling of a refrigeration cycle. is there. According to this, at the time of cooling of the refrigeration cycle, the liquid refrigerant condensed in the outdoor heat exchanger is introduced into the subcooling heat exchanger, and while flowing through the refrigerant flow path in the supercooling heat exchanger, It is supercooled by heat exchange. Subsequently, the liquid refrigerant is decompressed and expanded by an expansion valve or the like and reaches the indoor heat exchanger inlet, where the refrigerant evaporates and the indoor air is cooled.

[0003] Here, since the liquid refrigerant is sufficiently subcooled, the difference in enthalpy of the refrigerant between the inlet and the outlet of the evaporator (indoor heat exchanger) can be increased, and the cooling capacity of the heat pump is improved.

[0004]

However, in this type of heat pump device, during cooling, the liquid refrigerant condensed in the outdoor heat exchanger is passed through a supercooling heat exchanger to improve the cooling capacity. At the time of heating, the refrigerant condensed in the indoor heat exchanger flows by bypassing the subcooling heat exchanger,
The supercooling heat exchanger is not used as an evaporator for evaporating the refrigerant to absorb the outside air. The reason is as follows.

That is, during supercooling, the refrigerant flowing in the subcooling heat exchanger is in a liquid phase and does not change its phase. It is known that in such a liquid refrigerant, the heat transfer coefficient increases as the flow rate of the refrigerant increases. Therefore, in the related art, the heat transfer coefficient is secured by preventing the flow velocity from being reduced by making the refrigerant flow path in the subcooling heat exchanger a single serial flow path from the inlet to the outlet. By the way, if a plurality of refrigerant channels are caused to flow at the same time, the refrigerant is distributed and the flow velocity is reduced, so that the heat transfer coefficient is reduced and sufficient supercooling is not performed.

On the other hand, when the refrigerant expanded under reduced pressure is supplied to the supercooling heat exchanger during heating to absorb the outside air, the low-pressure refrigerant (gas-liquid two-phase refrigerant) evaporates in the supercooling heat exchanger. Since the specific volume of the refrigerant increases, the pressure loss in one serial refrigerant flow path becomes excessive. As a result, the suction pressure of the compressor that circulates the refrigerant is reduced, and the amount of the circulated refrigerant is reduced. As a result, sufficient external heat absorption is not performed, and the heating capacity is not effectively improved.

As described above, there is a problem that the supercooling heat exchanger added for improving the cooling capacity at the time of cooling does not effectively work for improving the heating capacity at the time of heating. The present invention has been made in view of the above points, and in a heat pump device capable of switching between cooling and heating by circulating a refrigerant by a compressor, supercooling the refrigerant during cooling and evaporating the refrigerant during heating to absorb outside air. Provide heat exchange means that can
The purpose is to improve the heating capacity.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies focusing on the pressure loss in the subcooling heat exchanger, and have adopted the following technical means. That is, claim 1
According to the invention, in a heat pump apparatus capable of switching between cooling and heating by circulating the refrigerant in the compressor (1), the liquid refrigerant from the gas-liquid separator (5) is supercooled during cooling, and the pressure reducing means for heating is heated during heating. A heat exchange means (9) for evaporating the refrigerant decompressed and expanded in (11a) is provided. This heat exchange means (9) has a plurality of refrigerant flow paths (92 to 94), and has a larger air temperature at the time of heating than at the time of cooling. In this case, the number of parallel refrigerant flow paths through which the refrigerant flows at the same time is increased.

Accordingly, during cooling, the liquid refrigerant condensed in the outdoor heat exchanger (4) and gas-liquid separated in the gas-liquid separator (5) is supercooled by the heat exchanging means (9). Can be improved, and the pressure loss in the refrigerant flow path in the heat exchange means (9) can be reduced during heating as compared with during cooling, so that
A decrease in the amount of circulating refrigerant is suppressed, sufficient heat absorption of outside air can be performed, and the heating capacity can be improved.

Here, as the heat exchange means (9), specifically, as in the invention of claim 3, a plurality of refrigerant flow paths (92-94) of the heat exchange means (9) are connected in series during cooling. Valve means (7b to 7i, 10a to 10f) for switching to a parallel relation at the time of heating, and a refrigerant flow path (92)
To 94), and a collecting part (90) for collecting the refrigerant flowing out of the refrigerant channels (92 to 94) during heating.

As a result, at the time of cooling, the refrigerant condensed in the outdoor heat exchanger (4) is supplied to the same refrigerant flow path (92 to 92).
94) to flow in series in series to form one flow path,
The heat transfer rate can be secured without reducing the flow velocity. On the other hand, during heating, the refrigerant decompressed by the heating decompression means (11a)
Since the refrigerant is simultaneously distributed to the refrigerant flow paths (92 to 94) by the distribution means (91) and flows in parallel in the respective refrigerant flow paths (92 to 94), the pressure loss can be reduced. Therefore, the heat exchange means (9) can effectively act on both the cooling capacity improvement and the heating capacity improvement.

Further, according to the invention of claim 2, according to claim 1,
In addition to the invention described above, the heating pressure reducing means (11
A part of the refrigerant depressurized in a) is sent to the heat exchange means (9), and the rest is sent to the outdoor heat exchanger (4). Thereby, at the time of heating, heat exchange means (9)
And the outdoor heat exchanger (4) can simultaneously absorb outside air.

The concrete means of the invention of claim 2 includes:
According to the fourth aspect of the present invention, the branched auxiliary circuit (6, 1
4), the refrigerant depressurized by the heating decompression means (11a) at the time of heating flows through the auxiliary circuits (6, 14) and is diverted at the branch portion (6a) to exchange heat with the outdoor heat exchanger (4). Means (9).

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention. In the present embodiment, the heat pump device according to the present invention is used as an indoor air conditioner. FIG.
FIG. 1 is a circuit diagram showing the entire configuration, in which a compressor (compressor) 1 for compressing and discharging a refrigerant is set, and in the present embodiment, the compressor 1 is driven by an engine (not shown).

The refrigerant discharged from the compressor 1 is supplied to a four-way valve (switching device) 2. The four-way valve 2 controls the circulation direction of the refrigerant discharged from the compressor 1 to the indoor heat exchanger 3 or the outdoor heat exchanger. In the heating, the refrigerant discharged from the compressor 1 is guided to the indoor heat exchanger 3 as shown by a solid line in FIG.
During cooling, the refrigerant discharged from the compressor 1 is guided to the outdoor heat exchanger 4 as shown by a dotted line in FIG.

An indoor fan 3a is set in the indoor heat exchanger 3, and the air flow generated by the indoor fan 3a is guided through the indoor heat exchanger 3 into the room to be cooled and heated. The outdoor fan 4 is connected to the outdoor heat exchanger 4.
a is set, and the airflow generated by the outdoor fan 4a is blown out through the outdoor heat exchanger 4 to the outside to exchange heat with the refrigerant flowing through the outdoor heat exchanger 4.

Here, the outdoor heat exchanger 4 is provided with a plurality (four in the present embodiment) of U-shaped refrigerant flow passages 40 arranged in parallel. It is connected to a header 41, which is a collecting tank, and a well-known distributor (distributor) 42 for distributing and merging the refrigerant. The header 41 and the four-way valve 2 are connected by a refrigerant pipe.

The distributor 42 of the outdoor heat exchanger 4
And a receiver (gas-liquid separator) 5 that separates the refrigerant into gas and liquid and sends out only the liquid refrigerant, is connected by a refrigerant pipe 6. Here, the refrigerant pipe 6 has an electromagnetic valve 7 for opening and closing the pipe.
a is set to intervene. Further, a receiver pipe 5 is connected to a heat exchanger 9 which is a heat exchange means to be described later by a refrigerant pipe 8, and an electromagnetic valve for opening and closing a pipe is provided in a part of the refrigerant pipe 8 near the heat exchanger 9. 7b is interposed and set.

The above-described solenoid valves 7a and 7b and other solenoid valves 7c to 7c to be described later in the present embodiment.
Each of 7k (11 in total) opens and closes a pipe (flow path) by energization. Next, the heat exchanger 9 will be described. The heat exchanger 9 functions as a supercooler for supercooling the liquid refrigerant from the receiver 5 during cooling, and functions as an evaporator for evaporating the refrigerant decompressed and expanded by the heating expansion valve 11a during heating.

The heat exchanging means 9 includes a header (collecting portion) 90 as a tank in which the refrigerant is collected and a well-known distributor (distributor) 91 as a distributing means for simultaneously distributing the refrigerant. Distributor 91
A U-shaped refrigerant flow path (a first refrigerant flow path 92, a second refrigerant flow path 93, a third refrigerant flow path 9
4) are provided in parallel (three in this embodiment). Note that the pipe diameters of these refrigerant channels are the same.

Here, a distributor 91 is provided in each refrigerant channel.
From the side toward the header 90, a plurality of valves are interposed and set as shown below. That is, the first refrigerant flow path 92 includes the distributor-side electromagnetic valve 7c, the check valve 10a, and the header-side electromagnetic valve 7d, and the second refrigerant flow path 93 includes the distributor-side electromagnetic valve 7e, The stop valve 10b and the solenoid valve 7f on the header side are provided in the third refrigerant flow path 94 with the solenoid valve 7 on the distributor side.
g, the check valve 10c and the solenoid valve 7h on the header side are interposed and set in this order. Here, each check valve 1
Each of 0a to 10c is set to prevent the backflow of the refrigerant to the distributor 91.

Further, the first refrigerant flow path 92, the second refrigerant flow path 93, and the third refrigerant flow path 94 are respectively provided at two positions between the check valve and the header side solenoid valve. A branch is provided. Of these two branch portions, the branch portion closer to the check valve is a first branch portion, and the branch portion closer to the header-side solenoid valve is a second branch portion. The U-shaped bent portion of each refrigerant flow path is located between these two branch parts, and the flow path length between these two branch parts is a predetermined length at which the refrigerant flowing during heating sufficiently absorbs outside air. It is the flow path length.

The refrigerant pipe 8 is connected to the first branch portion 92a of the first refrigerant flow path 92, whereby the receiver 5 and the heat exchanger 9 are connected as described above. Will be. Further, the second branch portion 92b of the first coolant channel 92 and the second branch portion 93a of the second coolant channel 93 are connected by a coolant channel having a check valve 10d interposed therebetween. Between the first branch portion 93b of the second coolant channel 93 and the second branch portion 94a of the third coolant channel 94, a coolant channel provided with a check valve 10e is provided. They are connected. In this way, a refrigerant flow path that connects the first to third refrigerant flow paths 92 to 94 in series is formed.

The second branch portion 94b of the third refrigerant flow path 94 and a heating expansion valve (heating decompression means) 11a for reducing the pressure of the refrigerant only during heating are connected by a refrigerant pipe 12. The refrigerant pipe 12 has a second branch portion 94.
b from the heating valve 11a toward the heating expansion valve 11a.
i, the check valve 10f is interposed and set in this order, and the check valve 10f is set so as to prevent the backflow of the refrigerant to the second branch portion 94b (heat exchanger 9).

As described above, each of the above-described solenoid valves 7b to 7i
And the check valves 10a to 10f are used for heating and cooling,
It is configured as a valve means of the heat exchanger 9 for switching the respective refrigerant flow paths. Further, between the heating expansion valve 11a and the indoor heat exchanger 3, a cooling expansion valve (cooling decompression means) 11b for reducing the pressure of the refrigerant only during cooling is provided. Here, as is well known, the heating expansion valve 11a and the cooling expansion valve 11b detect the refrigerant temperature and the refrigerant pressure at the outlet of the heat exchanger that becomes the evaporator during operation with a temperature sensor and a pressure sensor, respectively. An electronic expansion valve that controls the valve opening in accordance with detection signals from these sensors is used. These two expansion valves may be replaced by one fixed throttle such as a capillary tube.

The header 90 of the heat exchanger 9 and the header 41 of the outdoor heat exchanger 4 are connected by a refrigerant pipe 13, and a check valve 10g is interposed in the refrigerant pipe 13 for heat exchange. The backflow of the refrigerant to the vessel 9 is prevented. By the way, the check valve 10f of the refrigerant pipe 12
A branch portion 12a is provided in a portion between the heating valve 11a and the heating expansion valve 11a, and a refrigerant pipe 14 branches from the branch portion 12a. On the other hand, a branch portion 6a is provided in a portion of the refrigerant pipe 6 between the outdoor heat exchanger 4 and the electromagnetic valve 7a, and a refrigerant pipe 14 is connected to the branch portion 6a. This refrigerant pipe 14
A solenoid valve 7j and a check valve 10h are interposed in this order from the branch portion 12a toward the refrigerant pipe 6 side,
The check valve 10h is set so as to prevent the refrigerant from flowing back to the branch portion 12a. A portion of the refrigerant pipe 14 and the refrigerant pipe 6 between the branch portion 6a and the distributor 42 is configured as an auxiliary circuit that connects the heating expansion valve 11a and the outdoor heat exchanger.

Further, a refrigerant pipe 15 is provided which branches off from the branch portion 6a of the refrigerant pipe 6 and communicates with the distributor 91 of the heat exchanger 9, and the refrigerant pipe 15 is provided with an electromagnetic valve 7k. The heating expansion valve 11 a is connected to the indoor heat exchanger 3, and the indoor heat exchanger 3 is connected to the four-way valve 2. An accumulator 16 is provided between the four-way valve 2 and the suction side of the compressor 1 for separating the refrigerant into gas and liquid and sending out only the gas refrigerant.

The above-mentioned engine (not shown), compressor 1, four-way valve 2, expansion valve 11, and indoor fan 3
a, the outdoor fan 4a and each of the solenoid valves 7a to 7k are controlled by a control device constituted by an electric circuit (not shown). In addition, this control device
A heating / cooling changeover switch for switching the heat pump device between a heating operation and a cooling operation.

Next, the operation of the above configuration will be described with reference to FIG.
And 2 will be described. First, the operation during cooling will be described. When the cooling switch of the heat pump device is turned on, the refrigerant flows as shown by a dotted arrow in FIG. still,
At this time, the open / close state of the eleven electromagnetic valves 7a to 7k is such that the electromagnetic valves 7a, 7b and 7i are open (O in the figure) and the remaining electromagnetic valves 7c to 7h, 7j and 7
k is in a closed state (S in the figure).

That is, the high-temperature and high-pressure refrigerant discharged from the compressor 1 is introduced into the header 41 of the outdoor heat exchanger 4 through the four-way valve 2, and a plurality of (four) parallel refrigerant flow paths 4 are provided.
3 and is cooled by heat exchange with the airflow generated by the outdoor fan 4a. The refrigerant flowing out of each refrigerant flow path 42 joins in the distributor 41 of the outdoor heat exchanger, flows through the refrigerant pipe 6, and reaches the receiver 5. In the receiver 5, the refrigerant is gas-liquid separated, and only the liquid refrigerant exits the receiver 5 and flows through the refrigerant pipe 8, and flows into the first branch 9 of the first refrigerant flow path 92 of the heat exchanger 9.
2a.

Subsequently, the refrigerant flows in the heat exchanger 9 as follows. From the first branch portion 92a to the first refrigerant flow path 92
And flows from the second branch portion 92b to the first branch portion 93a through the check valve 10d. Subsequently, the first branch 9
3a, flows through the second coolant channel 93, and flows into the second branch 93
b, the check valve 10e, the first branch portion 94a,
Flows through the refrigerant passage 94 to the second branch portion 94b. In this way, the refrigerant flows through one serial refrigerant flow path and is supercooled.

The supercooled refrigerant passes through the fully opened heating expansion valve 11a, is decompressed by the cooling expansion valve 11b, evaporates in the indoor heat exchanger 3, and is cooled in the room. Subsequently, the evaporated refrigerant reaches the accumulator 16 from the four-way valve 2, is separated into gas and liquid, and the gas refrigerant returns to the compressor 1.
Next, the operation during heating will be described. When the heating switch of the heat pump device is turned on, the refrigerant flows as shown by the solid arrow in FIG. At this time, the eleven electromagnetic valves 7
As shown in FIG.
a, 7b and 7i are closed, and the remaining solenoid valves 7c to 7c
h, 7j and 7k are open.

That is, the high-temperature and high-pressure refrigerant discharged from the compressor 1 is introduced into the indoor heat exchanger 3 through the four-way valve 2 and condensed in the indoor heat exchanger 3 to heat the room. Subsequently, the pressure is reduced by the heating expansion valve 11a through the fully opened cooling expansion valve 11b. And the branch part 12a
Flows through the refrigerant pipe 14, and is divided into the heat exchanger 9 direction and the outdoor heat exchanger 4 direction at the branch portion 6 a of the refrigerant pipe 6.

The refrigerant diverted in the direction of the heat exchanger 9 flows through the refrigerant pipe 15 and is simultaneously and uniformly distributed in three directions by the distributor 91. The distributed refrigerants simultaneously flow through the first to third refrigerant flow paths 92 to 94 in parallel, respectively, to absorb heat from outside air, and the refrigerant exiting each refrigerant flow path is collected in the header 90. As described above, during heating, the refrigerant flows through the first to third refrigerant flow paths 92 to 94 of the heat exchanger 9 in parallel at the same time to absorb outside air.

On the other hand, the refrigerant diverted in the direction of the outdoor heat exchanger 4 flows through the refrigerant pipe 6 as it is, and is simultaneously distributed and introduced from the distributor 42 to each of the refrigerant channels 40. Subsequently, the refrigerant flows through each of the refrigerant flow paths and absorbs outside air, and the refrigerant flowing out of each of the refrigerant flow paths is collected in the header 41. Then, the refrigerant that has passed through the check valve 10 g from the header 90 of the heat exchanger 9 joins the refrigerant, passes through the four-way valve 2, reaches the accumulator 16, is separated into gas and liquid, and returns to the compressor 1.

In the present embodiment, the first to third refrigerant passages 92 to 94 of the heat exchanger 9 are connected in series during cooling to form one refrigerant passage, and a plurality of parallel refrigerant passages during heating. The refrigerant channel is used, and the reason will be described below. Normally, the refrigerant supercooled by the heat exchanger that becomes a supercooler during cooling is in a liquid phase and does not change phase, so that the heat transfer coefficient increases with an increase in the refrigerant flow rate.

FIG. 3 is a diagram schematically showing a change in the flow velocity of the refrigerant due to an increase in the number of refrigerant flow paths. Where v and t
_in is the refrigerant flow rate and the refrigerant temperature at the heat exchanger inlet, respectively. When the number of the refrigerant channels is one (at the time of cooling), the refrigerant flow rate v does not change at the inlet of the refrigerant channel, but when the number of the refrigerant channels is n (at the time of heating, n = 3 in the present embodiment), Are distributed to n lines, the refrigerant flow velocity is reduced to v / n. here,
The heat transfer coefficient α is represented by the following equation (A).

Α = f (Re), where Re = v · d / ν ‥‥‥ (A) (d: pipe diameter of refrigerant flow path, ν: kinematic viscosity coefficient of refrigerant) In the present embodiment, cooling The refrigerant flow path having the same pipe diameter is switched between series and parallel at the time of heating and at the time of heating, and since the refrigerant is the same, the pipe diameter d and the kinematic viscosity of the refrigerant flow path at the time of cooling and at the time of heating are changed. The coefficient ν can be regarded as a constant without change. Therefore, the heat transfer coefficient and the supercooling temperature (refrigerant temperature at the outlet of the heat exchanger) when the number of the refrigerant channels is one are α and t _out , respectively, and the heat transfer coefficient and the subcooling when the number of the refrigerant channels is n When the temperature alpha 'and t' _{ou t,} a relationship of the alpha> alpha 'and t _out <t' _out as shown in FIG.

Therefore, if a plurality of parallel refrigerant flow paths are used for cooling as well as for heating, the flow velocity decreases, the heat transfer coefficient decreases, and sufficient supercooling is not performed. Conversely, if a single refrigerant flow path is used during heating as in the case of cooling, the specific volume of the refrigerant increases due to evaporation of the low-pressure refrigerant, so that the pressure loss increases, and the suction of the compressor 1 The pressure decreases, the refrigerant circulation amount decreases, and sufficient external air heat absorption is not performed.

For the above reasons, in the heat exchanger 9 of the present embodiment, one cooling medium flow path is used during cooling.
During heating, a plurality of parallel refrigerant flow paths are provided. Therefore, at the time of cooling, it is condensed in the outdoor heat exchanger 4 and the receiver 5
Is supercooled sufficiently in the heat exchanger 9, while the refrigerant decompressed by the heating expansion valve 11a evaporates in the heat exchanger 9 and sufficiently absorbs outside air during heating. Therefore, in the present embodiment, the heat exchanger 9 can be effectively operated for improving the cooling capacity and the heating capacity.

According to the present embodiment, the number of times the flowing refrigerant turns in the heat exchanger 9 is as follows during heating (once).
The number of times can be reduced as compared with the cooling time (5 times). Here, the term “turn” refers to changing the direction in which the refrigerant flows. Therefore, during heating, pressure loss due to this turn can be reduced. In the present embodiment, the number of refrigerant flows is controlled by controlling the open / close states of the solenoid valves 7c, 7e, and 7g on the distributor 91 side in the refrigerant flow paths 92 to 94 of the heat exchanger 9. Since the number can be changed to one, two or three, the magnitude of the pressure loss of the heat exchanger 9 can be adjusted according to the operating state during heating.

In this embodiment, during heating,
The refrigerant flows in parallel in the heat exchanger 9 and the outdoor heat exchanger 4 to absorb the outside air. After absorbing the external air in the heat exchanger 9, the refrigerant flows in the outdoor heat exchanger 4 in parallel. You may make it heat-absorb outside air.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an overall configuration of a heat pump device according to an embodiment of the present invention.

FIG. 2 is a table showing an open / closed state of a solenoid valve according to the embodiment of the present invention.

FIG. 3 is a schematic diagram illustrating a change in refrigerant flow velocity due to an increase in the number of refrigerant flow paths in the heat exchanger according to the embodiment of the present invention.

[Explanation of symbols]

1 ... Compressor, 2 ... Four-way valve, 3 ... Indoor heat exchanger, 4
... outdoor heat exchanger, 5 ... receiver, 6 ... refrigerant pipe, 6a ...
Branch, 7b-7i ... solenoid valve, 9 ... heat exchanger, 10a-
10f ... check valve, 11a ... heating expansion valve, 11b ... cooling expansion valve, 14 ... refrigerant pipe, 15 ... refrigerant pipe, 90 ... header, 91 ... distributor, 92 ... first refrigerant flow path, 93 ... Second refrigerant flow path, 94... Third refrigerant flow path.

Claims (4)

[Claims] 1. A compressor (1) for compressing and discharging a refrigerant, an indoor heat exchanger (3) for exchanging heat between the refrigerant and indoor air, and a heat exchange between the refrigerant and outdoor air. An outdoor heat exchanger (4) for performing heating; a heating decompression means (11a) provided between the indoor heat exchanger (3) and the outdoor heat exchanger (4) for decompressing the refrigerant during heating; A cooling pressure reducing means (11b) provided between the indoor heat exchanger (3) and the outdoor heat exchanger (4) for reducing the pressure of the refrigerant during cooling; A switching device (2) for switching a circulation direction between the indoor heat exchanger (3) side and the outdoor heat exchanger (4) side, and a refrigerant condensed in the outdoor heat exchanger (4) during cooling. Gas-liquid separator that separates liquid and sends out only liquid refrigerant (5)
A heat exchange device (9) that supercools the liquid refrigerant from the gas-liquid separator (5) during cooling and evaporates the refrigerant decompressed and expanded by the heating decompression device (11a) during heating. ), And the heat exchange means (9) includes a plurality of refrigerant flow paths (92 to 9).
4) The heat pump device according to (1), wherein the number of parallel refrigerant flow paths through which refrigerant flows at the time of heating is greater than at the time of cooling. 2. During heating, the heating decompression means (11)
Part of the refrigerant decompressed in a) is supplied to the heat exchange means (9).
The heat pump device according to claim 1, wherein the remainder is sent to the outdoor heat exchanger (4). 3. The heat exchange means (9) is arranged such that the refrigerant flow paths (92-94) are connected in series during cooling, and the refrigerant flow paths (92-94) are connected in parallel during heating. Switching valve means (7b to 7i, 10a
-10f), a distribution means (91) for simultaneously distributing the refrigerant depressurized by the decompression means for heating (11a) to the refrigerant flow paths (92-94) during heating, and the refrigerant flow path (92) during heating. ~ 9
The heat pump device according to claim 1, further comprising a collecting portion (90) for collecting the refrigerant discharged from 4). 4. The heating decompression means (11a) during heating.
An auxiliary circuit (6, 14) through which the refrigerant decompressed in the above is sent to the outdoor heat exchanger (4); a branch portion (6a) provided in the middle of the auxiliary circuit (6, 14); Branching off from the section (6a),
And a branch circuit (15) that communicates with the refrigerant. During heating, the refrigerant depressurized by the heating depressurizing means (11a) flows through the auxiliary circuit (6, 14) and passes through the branch part (6a). Heat pump according to claim 3, characterized in that the diverted flow is partially introduced into the heat exchange means (9) and the remainder is introduced from the branch circuit (15) into the outdoor heat exchanger (4). apparatus.