JPH10193954A - Refrigerant recovery system for heat pump type air conditioner for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely recover refrigerants without any factor of reducing the reliability of a compressor itself by providing a refrigerant recovery line which guides the refrigerants flowing out from a first condenser in heating operation to a second cooling cycle. SOLUTION: When a first and a third opening/closing valve V1, V3 are in opened states, a second opening/closing valve V2 is in a closed state, and a compressor 1 is operated, a part of refrigerants being asleep inside the first condenser 3 flows out from the first condenser 3 which is a part of the first cooling cycle, to a first evaporator 12 and returns to the compressor 1 with comparatively decreasing the quantity of the liquid refrigerant. Other refrigerants being asleep inside the first condenser 3 are guided to a second cooling cycle. The residual refrigerants pass through the composition parts of the second cooling cycle so as to be recovered in the compressor 1. In this case, the recovered refrigerants have less liquid refrigerant so as to eliminate any possibility of liquid compression and provide the device with normal 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 type air conditioner for a vehicle in which the interior of a vehicle is cooled and heated by using engine cooling water and a refrigerant, and more particularly to a refrigerant stored in a cycle during heating. The present invention relates to a refrigerant recovery system for recovering a refrigerant.

[0002]

2. Description of the Related Art In a dual-type heat pump type air conditioner for automobiles, which cools and heats front and rear seats respectively incorporated in a luxury car, a one-box car having a large cabin space, and the like, a heating operation is performed after the operation is started. Warm air does not immediately blow out, so-called lack of immediate warming, and heating performance tends to be insufficient.

[0003] Therefore, in order to solve such a problem, the present applicant heats the refrigerant by using the heat of the engine cooling water and converts the refrigerant having changed isentropy into the compressor 1.
And a heat pump type air conditioner for automobiles which exhibits high heating performance by compressing the compressed air again (see Japanese Patent Application No. 7-271,621).

In this vehicle air conditioner, as shown in FIG. 2, refrigerant flowing out of a second evaporator 22 of a rear unit 20 flows into a sub heat exchanger 30, and the sub heat exchanger 30 This heats the refrigerant.

[0005] In FIG. 3, "1" is a compressor,
"2" is the engine, "3" is the first condenser, "4a"
Is a first liquid tank, “4b” is a second liquid tank, “5a” is a first expansion valve, “5b” is a second expansion valve,
“7” is a four-way valve, “10” is a front unit, “1”
"1" is a heater core, "11a, 11b" is a hot water cock,
"12" is a first evaporator, "21" is a second condenser, and "W" is a hot water circuit (shown by a broken line in the figure).

[0006] The engine cooling water, which could not be used immediately for heating even if heat exchanged with air because of low temperature in the past, is exchanged with the extremely low temperature refrigerant in the sub heat exchanger 30 to provide engine cooling water. After effectively taking the heat held by the refrigerant into the refrigerant, it is returned to the compressor 1,
Since this is pressurized again, the refrigerant discharged from the compressor 1 can be supplied to the second condenser 21 as a high-temperature isenthalpy-changed refrigerant. The exchanged air has a higher temperature, exhibits high heating performance, and has an improved immediate warming property.

[0007] However, in the air conditioner for a vehicle configured as described above, since the cooling cycle and the heating cycle are shared, when switching between the cooling and the heating, the switching time, the recovery of the refrigerant, and the like become problems.

For example, in a general home air conditioner, when switching from the cooling operation to the heating operation, only the direction of the flow of the refrigerant is changed using a four-way valve. There is little so-called stagnant refrigerant that can be used and stays in the circuit, and there is no danger of shortage of refrigerant at the time of cooling / heating switching. Therefore, there is no need to consider the recovery of the refrigerant.

However, when switching from cooling to heating or from heating to cooling, it cannot be changed immediately, and a stop time of about 3 minutes is required.

However, the method of switching between cooling and heating, which requires a stop time every time the direction of the flow of the refrigerant is changed, cannot be applied to an air conditioner for an automobile.
In other words, if the operation is stopped for a long time of three minutes to switch between cooling and heating, window fogging occurs during this blank time, which is not practical.

For this reason, in an air conditioner for a vehicle, a method as shown in FIG. 3 is employed in order to instantaneously switch between cooling and heating. In this method, switching between cooling and heating is performed without changing the flow of the refrigerant.

That is, during the cooling operation, the four-way valve 7 is in a state shown by a solid line, and the first operating valve 8 and the second operating valve 9 are "throttle".
By setting the state, the refrigerant from the compressor 1 is discharged from the four-way valve 7 → the outdoor heat exchanger (condenser 3) → the liquid tank 4 → the first operating valve 8 → the first heat exchanger 12 → the second operating valve 9 → the second. (2) Flow with the heat exchanger 12a. Thereby, both the first heat exchanger 12 and the second heat exchanger 12a function as evaporators, and cool the interior of the vehicle.

During the heating operation, the four-way valve 7 is set to the state shown by a broken line, the first operating valve 8 is set to "open", and the second operating valve 9 is set to the "throttled" state. Valve 7 → bypass circuit B → liquid tank 4 →
1st working valve 8 → 1st heat exchanger 12 → 2nd working valve 9 → 2nd
It is made to flow with the heat exchanger 12a. As a result, the first heat exchanger 12 serves as a sub-condenser, and the second heat exchanger 12
a functions as an evaporator and heats the vehicle interior.

Thus, switching between cooling and heating can be performed instantaneously without changing the flow of the refrigerant. However, on the other hand,
At the time of heating, a large amount of refrigerant is stored in the main condenser having a large capacity. Unless this is collected, there is a possibility that the desired heating performance may not be exhibited. Therefore, during the heating operation, the refrigerant collected in the outdoor heat exchanger 3 is recovered by the compressor 1 by the refrigerant recovery line, and a desired heating capacity is exhibited by using a large amount of the refrigerant.

According to this method, the volume of the outdoor heat exchanger 3 is small in the case of a general automobile or electric vehicle in which the internal volume of the components constituting the cooling / heating cycle is relatively small.
The amount of refrigerant accumulated here is also small and can be used without any problem.

[0016]

However, in the above-mentioned dual type heat pump type air conditioner for automobiles incorporated in a luxury car or a one-box car having a large cabin space as described above, the capacity of the condenser is large. ,
Since the piping is long, there is a concern that it takes time to collect the refrigerant.

For example, when only the rear unit is cooled and heated by a heat pump system, no refrigerant is required on the front unit side. Therefore, when the refrigerant on the front unit side, that is, the liquid refrigerant accumulated in the evaporator or the like is also recovered, When the refrigerant is recovered, a large amount of liquid refrigerant enters the compressor, causing a possibility of liquid compression of the compressor, outflow of oil, cleaning of the interior with the refrigerant, and the like, which is a factor that lowers the reliability of the compressor itself. .

The present invention has been made in view of such problems of the prior art, and is an inexpensive and highly reliable heat pump capable of reliably recovering a refrigerant without causing a reduction in the reliability of the compressor itself. It is an object of the present invention to provide an automotive air conditioner of the type.

[0019]

According to a first aspect of the present invention, there is provided a heater core through which engine cooling water from an engine flows through a first unit, and a compressor driven by the engine. A first condenser into which the refrigerant discharged from is introduced through a first on-off valve,
A first evaporator that constitutes a first cooling cycle together with the first liquid tank and the first expansion valve;
A second condenser constituting a second cooling cycle, in which a part of the refrigerant discharged from the compressor is introduced through a second opening / closing valve, a second liquid tank and a second liquid tank; In a heat pump type vehicle air conditioner including a second evaporator connected via an expansion valve, refrigerant recovered from the first condenser during a heating operation is guided into a second cooling cycle. It has a line.

In this manner, the first heating operation is performed at the beginning of the heating operation.
The refrigerant lying in the condenser enters the second cooling cycle through the refrigerant recovery line and is returned to the compressor. In this case, the recovered refrigerant is returned through the second cooling cycle, so that the second refrigerant is returned. While passing through the various components that make up the cooling cycle, the liquid refrigerant becomes a vaporized refrigerant, which may cause liquid compression of the compressor and oil outflow.
The reliability of the compressor itself is not reduced by washing or the like.

According to the second aspect of the present invention, the refrigerant recovery line is configured to transfer the refrigerant discharged from the first condenser to the first condenser.
It is characterized in that it is collected in the second liquid tank.

In this way, when the refrigerant that has been stored in the first condenser passes through the refrigerant recovery line and enters the second cooling cycle, part of the refrigerant is stored in the second liquid tank. However, this refrigerant is used immediately after the heating operation or the like is started, and it is possible to prevent oil from flowing out of the compressor by an amount that is not unnecessarily returned to the compressor. Become.

Moreover, when most of the recovered refrigerant is returned to the compressor through the second liquid tank, the refrigerant is returned through the second expansion valve and the second evaporator of the second cooling cycle and passes through these components. Since the refrigerant is vaporized from the liquid refrigerant in the interior, it is possible to prevent liquid compression of the compressor, outflow of oil, washing, and the like.

According to the third aspect of the present invention, the refrigerant recovery line communicates the outlet of the first condenser and the outlet of the second condenser by a conduit, and the third conduit is opened to the conduit during a heating operation. An on-off valve and a one-way valve for flowing the refrigerant flowing out of the first condenser toward the second condenser are provided.

In this way, since the refrigerant recovery line is constituted by the on-off valve and the one-way valve, it is advantageous in terms of cost and is inexpensive.

In the invention described in claim 4, the heat pump type air conditioner for a vehicle guides the refrigerant flowing out of the second evaporator to a sub heat exchanger provided outside the first and second units. The refrigerant in the sub heat exchanger is heated by a part of the engine cooling water and returned to the compressor.

As described above, when the present invention is used for an air conditioner for a vehicle with a sub-heat exchanger, when returning a large amount of refrigerant to the compressor, it can be used to some extent for heating the refrigerant by the heat of the engine cooling water. And a higher heating performance can be obtained at the beginning even during the heating operation.

[0028]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an embodiment of a refrigerant recovery system in a heat pump type air conditioner for a vehicle according to the present invention. In addition, the same reference numerals are given to members common to FIG. 2, and in the figure, white arrows indicate the flow of air, solid arrows indicate the flow of refrigerant, and broken arrows indicate the flow of engine cooling water. ing.

As shown in FIG. 1, the heat pump type automotive air conditioner of the present embodiment air-conditions inside and outside air selectively taken in from an intake unit (not shown) and blows the air to the front seat. This is a so-called dual air conditioner having a front unit 10 as a first unit, and a rear unit 20 as a second unit for air-conditioning the inside air and blowing the air to a rear seat.

The front unit 10 includes an intake unit, an intake door, and an intake unit for selectively introducing air inside and outside the vehicle compartment into the air passage 10f formed by the casing in order from the upstream side in the air flow direction indicated by the white arrow. Blower motor (none shown), first evaporator 12, air mix door (not shown) and heater core 1
1 is provided, and an air outlet (not shown) to the vehicle interior is provided on the downstream side in the air flow direction.

The front unit 10 has an air mix door (not shown) at the front of the heater core 11.
To adjust the ratio of hot air to cold air to produce air at a predetermined temperature downstream of the heater core 11 or to prevent air from flowing through the heater core 11.

On the other hand, the rear unit 20 includes a blower (not shown) for introducing air in the passenger compartment into the air passage 20f formed in the casing in order from the upstream side in the air flow direction indicated by the white arrow. The second evaporator 22 and the second condenser 21 are arranged.

The rear unit 20 also has an air mix door (not shown) on the front surface of the second condenser 21.
And the ratio of hot air to cold air is adjusted to adjust the second condenser 2
Air at a predetermined temperature in the downstream area of 1
The structure is such that air does not flow through the condenser 21.

In this embodiment, the compressor 1,
A first cooling cycle in which a first on-off valve V1, a first condenser 3, a first liquid tank 4a, a first expansion valve 5a, and a first evaporator 12 are connected in series in this order by a refrigerant pipe; Valve V2, second condenser 21, second liquid tank 4b, second expansion valve 5b, second evaporator 2
2. A second cooling cycle in which the sub heat exchangers 30 are connected in series in this order by refrigerant piping.

The switching between the first cooling cycle and the second cooling cycle is performed by, for example, a combination of the opening and closing operations of a first opening / closing valve V1 and a second opening / closing valve V2 constituted by an electromagnetic valve or the like. Cooling operation and heating operation can be realized in the same cycle.

In particular, the present embodiment has a refrigerant recovery line R for guiding the refrigerant flowing out of the first condenser 3 during the heating operation of the rear unit into the second cooling cycle.

The refrigerant recovery line R is specifically designed to recover the refrigerant flowing out of the first condenser 3 into the second liquid tank 4b. 3 and the outlet of the second condenser 21 are communicated with each other by a conduit P. The conduit P has a third on-off valve V3 such as a solenoid valve which is opened during the heating operation, and the refrigerant is supplied to the first condenser V3. A one-way valve 40 is provided from the condenser 3 to the second condenser 21.

In this way, when the rear unit starts heating, the so-called refrigerated refrigerant that has accumulated in the first condenser 3 is returned into the second cooling cycle, and high-performance heating can be performed using a large amount of refrigerant. I have.

The heating operation can also be performed in the front unit 10. In this case, the flow of the refrigerant (the same applies to the cooling operation) is such that the refrigerant discharged from the compressor 1 is supplied to the first on-off valve V1. The first condenser 3 → the first liquid tank 4 a → the first expansion valve 5 a → the first evaporator 12 flows back to the compressor 1. During a normal heating operation, the engine 2 is opened by opening the hot water cock 11a of the hot water circuit W.
The engine cooling water having a relatively high temperature flowing out of the heater core 11 is introduced into the heater core 11, and the heater core 11 heats the air cooled by the first evaporator 12.

On the other hand, the flow of the refrigerant on the side of the rear unit 20 is such that the refrigerant branched from the main cooling cycle by opening the second opening / closing valve V2 during the cooling and heating is changed from the second condenser 21 to the second liquid tank 4b. Second expansion valve 5b →
It flows from the second evaporator 22 to the sub heat exchanger 30, and is returned to the compressor 1.

The sub heat exchanger 30 is provided with air passages 10f, 2 of the front unit 10 and the rear unit 20.
0f. In this sub heat exchanger 30,
Engine cooling water for exchanging heat with the refrigerant flowing inside is introduced by opening the hot water cock 11b from the engine 1. In the sub heat exchanger 30, the refrigerant flowing through the sub heat exchanger 30 is heated by the engine cooling water, so that the refrigerant whose isentropy has changed is returned to the compressor 1 so as to exhibit higher heating performance.

Next, the operation will be described. Refrigerant recovery operation ( early stage of heating operation) At the start of heating operation, when the outside air temperature is low (for example,-
Engine cooling water temperature is low,
It is difficult to use this immediately for heating, and the refrigerant is trapped inside the first condenser 3 and the like, and is not so much present in the compressor 1. If both the front and rear seats are heated in this state, there is a possibility that a shortage of refrigerant may occur.

Accordingly, first, the first on-off valve V1 and the third
The on-off valve V3 is opened and the second on-off valve V
2 is closed.

When the compressor 1 is operated, a part of the refrigerant stagnating inside the first condenser 3 is removed from the first condenser 3 which is a part of the first cooling cycle.
The liquid flows from the liquid tank 4a to the first expansion valve 5a to the first evaporator 12, and returns to the compressor 1. In other words, although a part of the stagnation refrigerant is a part of the components constituting the first cooling cycle, the liquid refrigerant evaporates and is collected by the compressor 1 when passing through each part. The amount of liquid refrigerant is reduced.

Further, the other refrigerant lying inside the first condenser 3 is drawn out by the suction action of the compressor 1, and the third on-off valve V3 of the refrigerant recovery line R → a relatively long conduit P → one direction. Flows through valve 40 and is directed to the second cooling cycle.

This refrigerant is partially stored in the second liquid tank 4b and prepared for the next heating operation. The remaining refrigerant is stored in the second expansion valve 5b → the second evaporator 22 → the sub heat exchanger 30. And flows into the compressor 1. Also in this case, the liquid refrigerant is reduced because the refrigerant is recovered by the compressor 1 after passing through the components constituting a part of the second cooling cycle. Further, even when returning a large amount of the refrigerant to the compressor, the refrigerant can be heated to some extent by the heat of the engine cooling water, and the return of the liquid refrigerant is reduced.

As a result, a large amount of refrigerant is discharged from the compressor 1 while a large amount of refrigerant is collected by the compressor 1. In this case, the collected refrigerant is relatively small in liquid refrigerant. There is no danger of liquid compression, no outflow of oil, no cleaning action by the refrigerant, etc., and the compressor 1 can operate normally and there is no danger that the reliability will be reduced. The refrigerant recovery line R is provided with a third on-off valve V3,
Since it is constituted by the conduit P and the one-way valve 40, it is advantageous in cost and is inexpensive.

Heating operation Next, when the heating operation is performed, the first on-off valve V1 and the third on-off valve V3 are set to the "closed" state, and the backflow of the refrigerant from the second cooling cycle side is prevented. Second on-off valve V
2 is in the “open” state.

As a result, a large amount of high-temperature and high-pressure refrigerant discharged from the compressor 1 is supplied to the second opening / closing valve V2 → the second condenser 21 → the second liquid tank 4b → the second expansion valve 5b →
It flows from the second evaporator 22 to the sub heat exchanger 30.

The engine cooling water whose temperature has risen to some extent also flows through the heater core 11 and the sub heat exchanger 30 when the engine 1 is started. However, the temperature of the engine cooling water at this time has not yet sufficiently risen. It is not preferable to use it for heating. Therefore, in such a state, in the front unit 10, the hot water cock 11a is closed to prevent engine cooling water from flowing into the heater core 11, or to prevent air from passing through the heater core 11 by a door (not shown). Is preferable. However, the rear unit 20 opens the hot water cock 11b to allow the engine cooling water to flow through the sub heat exchanger 30.

Although the front unit 10 is not heated by this, the high-temperature and high-pressure refrigerant enters the second condenser 21 from the second opening / closing valve V2 on the rear unit 20 side, and exchanges heat with the vehicle interior air. Heats the cabin air.

Also, after heating the cabin air, it condenses,
The medium-temperature, high-pressure refrigerant is adiabatically expanded by the second expansion valve 5b, becomes a low-pressure refrigerant at a lower temperature, enters the second evaporator 22, and exchanges heat with the vehicle interior air to cool the air. However, since it is not preferable that the cold air is discharged into the passenger compartment, the cold air may be discharged to the outside or a door may be arranged in front of the second evaporator 22 so that the air does not flow through the second evaporator 22. good.

Then, the low-temperature and low-pressure refrigerant evaporated in the second evaporator 22 flows to the sub heat exchanger 30. This refrigerant takes in the heat of the engine cooling water in the sub heat exchanger 30 and raises the temperature. Then, the refrigerant having the isentropic change is returned to the compressor 1 and compressed again, so that the temperature of the refrigerant discharged from the compressor 1 increases. In this case, the refrigerant returned to the compressor 1 is heated by the air in the second evaporator 22 and heated by the engine cooling water in the sub heat exchanger 30, so to speak, a so-called two-stage heating method, so that high heating performance is achieved. It can be demonstrated and the immediate warming property is improved. In addition, when the refrigerant after being heated is compressed again by the compressor 1, the temperature rise of the refrigerant is further accelerated, and when the refrigerant reaches the second evaporator 22, it is heated again, becomes higher in temperature, and has higher heating. It demonstrates its performance and blows out hot air into the cabin. This tendency is amplified as time passes, so that the so-called immediate warming property is improved.

If the temperature of the engine coolant rises while this operation is continued for a while, the engine coolant is also supplied to the heater core 11 of the front unit 10 to heat the front unit 10. In this case, the entire passenger compartment is heated. Further, since the heating capacity of the engine cooling water is increased and the heating capacity of the refrigerant by the sub heat exchanger 30 is also increased, a considerably high temperature air is blown out by the synergistic effect of these.

When the heating capacity of the second condenser 21 is increased in this way, a door (not shown) closing the front surface of the second evaporator 22 may be opened, thereby heating the dehumidified air. Dehumidifying and heating can be performed. This eliminates fogging of the windows in the rear seats and further enhances driving safety.

When the temperature of the engine cooling water rises to some extent during the stable period of the heating operation and the temperature of the vehicle interior also rises to some extent, the hot water cock 11b of the sub heat exchanger 30
Is closed to prevent engine cooling water from flowing into the sub heat exchanger 30. Thereby, the refrigerant is not unnecessarily heated, and the normal heating operation is performed.

The seats before and after the cooling operation may be cooled, but only the front seats may be cooled. In this case, the first on-off valve V1 is set to the "open" state, and the second on-off valve V2 and the third on-off valve V3 are set to the "closed" state.

When the compressor 1 is operated in this state,
On the first cooling cycle side, the refrigerant discharged from the compressor 1 is the first on-off valve V1 → the first condenser 3 → the first
The liquid flows from the liquid tank 4a to the first expansion valve 5a to the first evaporator 12.

Thus, the air introduced from the intake unit into the front unit 10 becomes low-temperature air dehumidified by exchanging heat with the low-temperature low-pressure refrigerant in the first evaporator 12.

This air is distributed to the heater core 11 side and the bus path side by an air mixing door (not shown), and the cool air and the hot air are mixed and brought to a predetermined temperature or mixed in the downstream area of the heater core 11. Instead, it is blown out toward the passenger compartment.

When the rear unit 20 is to be cooled, the second on-off valve V2 is set to the "open" state. As a result, the refrigerant decompressed by the second expansion valve 5b flows into the second evaporator 22, so that the air cooled here is supplied to the second condenser 2 by the air mixing door.
The cold air and the hot air are mixed in the downstream area of the second condenser 21 and are blown out toward the vehicle interior without being mixed at a predetermined temperature or without being mixed.

In this case, the refrigerant that has exited the second evaporator 22 enters the sub heat exchanger 30, but during the cooling operation, the hot water cock 11b is closed and the engine cooling water is supplied to the sub heat exchanger 3.
Do not flow into zero.

If only the rear seats are to be cooled, the first
The on-off valve V1 may be closed.

The present invention is not limited to the above-described embodiment, but can be variously modified within the scope of the claims. For example, in the embodiment, the heat pump type air conditioner having the sub heat exchanger 30 is used. However, the air conditioner may not necessarily include the sub heat exchanger 30. Not only the one in which the outlet of the second condenser 21 and the outlet of the second condenser 21 are communicated with each other by the conduit P, but also any one in which the refrigerant in the first cooling cycle is guided into the second cooling cycle.

[0065]

As described above, according to the first aspect of the present invention, the refrigerant recovery line for guiding the refrigerant flowing out of the first condenser during the heating operation into the second cooling cycle is provided. The recovered refrigerant is returned through the second cooling cycle and becomes a vaporized refrigerant from the liquid refrigerant, which may reduce the reliability of the compressor itself due to fear of liquid compression of the compressor, outflow of oil, washing, etc. Disappears.

According to the second aspect of the present invention, the refrigerant flowing out of the first condenser is collected in the second liquid tank. Therefore, when the heating operation or the like is started, the refrigerant is recovered. Used immediately and results in a more reliable compressor.

According to the third aspect of the present invention, the outlet of the first condenser and the outlet of the second condenser are connected by a conduit, and the conduit is provided with a third on-off valve and a one-way valve.
It is cost-effective and inexpensive.

According to the fourth aspect of the present invention, since the present invention is applied to an air conditioner for a vehicle having a sub heat exchanger, when returning a large amount of refrigerant to the compressor, the refrigerant is heated to some extent by the heat of the engine cooling water. The compressor can be used and has higher reliability, and the heating operation can also obtain higher heating performance at the beginning.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a conventional automotive air conditioner.

FIG. 3 is a schematic configuration diagram of another conventional vehicle air conditioner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... Engine, 3 ... 1st condenser, 4a ... 1st liquid tank, 4b ... 2nd liquid tank, 5a ... 1st expansion valve, 5b ... 2nd expansion valve, 10 ... Front unit (1st unit) ), 11: heater core, 12: first evaporator, 20: rear unit (second unit), 21: second condenser, 22: second evaporator, 30: sub heat exchanger, 40: one-way valve, P: conduit , R: refrigerant recovery line, V1, V2, V3: on-off valve.

Claims (4)

[Claims] 1. A heater core (11) through which engine cooling water from an engine (2) flows through a first unit (10), and a refrigerant discharged from a compressor (1) driven by the engine (2). Is introduced through the first on-off valve (V1)
A condenser (3), a first liquid tank (4a), and a first evaporator (12) constituting a first cooling cycle are arranged together with a first expansion valve (5a). The second unit (20) includes the compressor Part of the refrigerant discharged from (1) is introduced through the second on-off valve (V2),
A second condenser (21) constituting a second cooling cycle;
A second evaporator (2) connected to the second condenser (21) through a second liquid tank (4b) and a second expansion valve (5b).
And (2) a refrigerant recovery line (R) for guiding the refrigerant flowing out of the first condenser (3) into a second cooling cycle during a heating operation.
A refrigerant recovery system comprising: 2. The refrigerant recovery line (R) recovers the refrigerant flowing out of the first condenser (3) into the second liquid tank (4b). 2. The refrigerant recovery system according to 1. 3. The refrigerant recovery line (R) communicates an outlet of the first condenser (3) and an outlet of the second condenser (21) by a conduit (P), and the conduit (P) A third on-off valve (V2) opened during the heating operation, and the first condenser
The refrigerant recovery system according to claim 1, further comprising a one-way valve (40) for flowing the refrigerant flowing out of (3) toward the second condenser (21). 4. The air conditioner for a heat pump type vehicle according to claim 1, wherein the refrigerant flowing out of the second evaporator (22) is provided with a sub heat exchanger (30) provided outside the first and second units (10, 20). ), The refrigerant in the sub heat exchanger (30) is heated by a part of the engine cooling water and the compressor (1) is heated.
4. The method according to claim 1, wherein
The refrigerant recovery system according to any one of the above.