CN110497769A - Automobile heat pump system and its control method - Google Patents

Abstract

The invention relates to the technical field of automobile air conditioning, and discloses an automobile heat pump system and a control method thereof, wherein the automobile heat pump system includes a first in-vehicle heat exchanger and a second in-vehicle heat exchanger sequentially installed in the air-conditioning duct of the automobile along the air supply direction. The heat exchanger also includes a compression unit installed outside the air-conditioning duct, a heating expansion valve and the first external heat exchanger, the compression unit includes a first-stage compressor and a second-stage compressor; the first external heat exchanger The outlet, the first-stage compressor, the first in-vehicle heat exchanger, the second-stage compressor, the second in-vehicle heat exchanger, the heating expansion valve and the inlet of the first out-of-vehicle heat exchanger are connected in sequence to form a heating loop loop. The automobile heat pump system uses the first in-vehicle heat exchanger to cool the exhaust gas of the first-stage compressor of the compression unit, and at the same time uses the first in-vehicle heat exchanger to pre-heat the low-temperature air that has just entered the air-conditioning duct. Heating, effectively recovering the waste heat of intermediate cooling, and increasing the heating capacity in winter working conditions.

Description

Automobile heat pump system and its control method

technical field

The invention relates to the technical field of automobile air conditioners, in particular to an automobile heat pump system and a control method thereof.

Background technique

Under the dual pressure of energy structure transformation and energy conservation and emission reduction, pure electric vehicles have gradually become the main development direction of the automobile industry. Compared with traditional fuel vehicles, electric vehicles have an additional winter heating demand for automotive air conditioning because there is no waste heat from the engine to use. At present, electric vehicles generally use electric heaters to assist air-conditioning systems for heating in winter, but electric heating and heating are not only inefficient, but also consume a large amount of on-board power, which seriously affects the cruising range of electric vehicles. Electric vehicles are required to be equipped with higher-capacity batteries, greatly increasing vehicle cost and weight.

Air source heat pump is the best solution to solve the heating demand of electric vehicles at this stage. Existing electric vehicle heat pump systems mostly adopt single-stage compression mode. When the ambient temperature is low, due to the increase of pressure ratio, problems such as decreased compressor efficiency and high exhaust temperature are often caused, accompanied by serious system performance attenuation and heating problems. Insufficient problems affect the heating effect and cannot meet the winter heating demand in severe cold areas.

Contents of the invention

Embodiments of the present invention provide an automobile heat pump system and a control method thereof, which are used to solve the problems of low heating efficiency and insufficient heating in existing electric vehicles, so as to improve the heating effect of the vehicle.

An embodiment of the present invention provides an automobile heat pump system, which includes a first in-vehicle heat exchanger and a second in-vehicle heat exchanger installed in the air-conditioning air duct of the automobile in sequence along the air supply direction, and also includes a heat exchanger installed outside the air-conditioning air duct The compression unit, the heating expansion valve and the first external heat exchanger, the compression unit includes the first-stage compressor and the second-stage compressor; the outlet of the first external heat exchanger, the first-stage The compressor, the first in-vehicle heat exchanger, the second-stage compressor, the second in-vehicle heat exchanger, the heating expansion valve and the inlet of the first out-vehicle heat exchanger are connected in sequence , to form a heating cycle.

Wherein, it also includes a second exterior heat exchanger, the first port of the second exterior heat exchanger is connected to the inlet of the first exterior heat exchanger through a first cut-off valve, and the second exterior heat exchanger The second interface of the heat exchanger is connected to the outlet of the first external heat exchanger through a second cut-off valve.

Among them, it also includes low-pressure three-way valve, first medium-pressure three-way valve, second medium-pressure three-way valve, high-pressure three-way valve and refrigeration expansion valve;

The first port of the low-pressure three-way valve is connected to the outlet of the first external heat exchanger, the second port of the low-pressure three-way valve is connected to the inlet of the first-stage compressor, and the low-pressure three-way The third interface of the through valve is connected to the outlet of the first in-vehicle heat exchanger; the refrigeration expansion valve is arranged between the first interface of the low-pressure three-way valve and the inlet of the first in-vehicle heat exchanger;

The first port of the first medium-pressure three-way valve is connected to the outlet of the first-stage compressor, and the second port of the first medium-pressure three-way valve is connected to the port of the first in-vehicle heat exchanger. Inlet, the third port of the first medium-pressure three-way valve is connected to the second port of the second external heat exchanger;

The first port of the second medium-pressure three-way valve is connected to the outlet of the first in-vehicle heat exchanger, and the second port of the second medium-pressure three-way valve is connected to the outlet of the second-stage compressor. Inlet, the third port of the second medium pressure three-way valve is connected to the first port of the second external heat exchanger;

The first port of the high-pressure three-way valve is connected to the outlet of the second-stage compressor, the second port of the high-pressure three-way valve is connected to the inlet of the second in-vehicle heat exchanger, and the high-pressure three-way The third interface of the through valve is connected to the inlet of the first external heat exchanger.

Wherein, it also includes a regenerator, the first heat exchange side of the regenerator is connected in series between the outlet of the first in-vehicle heat exchanger and the third interface of the low-pressure three-way valve, the regenerator The second heat exchange side of the heater is connected in series between the refrigeration expansion valve and the first interface of the low pressure three-way valve.

Wherein, a gas-liquid separator is also included, the inlet of the gas-liquid separator is connected to the second port of the low-pressure three-way valve, and the outlet of the gas-liquid separator is connected to the inlet of the first-stage compressor.

An embodiment of the present invention also provides a control method for an automobile heat pump system, the automobile heat pump system adopts the above-mentioned automobile heat pump system, the control method includes a heating mode, and the heating mode includes: connecting the first outlet of the heat exchanger, the first-stage compressor, the first in-vehicle heat exchanger, the second-stage compressor, the second in-vehicle heat exchanger, the heating expansion valve and the first Inlet for an outside heat exchanger.

Wherein, the heating mode includes:

Open the first shut-off valve and the second shut-off valve, communicate with the first port and the second port of the low-pressure three-way valve, communicate with the first port and the second port of the first medium-pressure three-way valve, and communicate with the second medium-pressure three-way valve The first port and the second port of the high-pressure three-way valve communicate with the first port and the second port of the high-pressure three-way valve.

Wherein, it also includes a cooling mode, and the cooling mode includes:

closing the first shut-off valve and the second shut-off valve, communicating with the second port and the third port of the low-pressure three-way valve, and communicating with the first port and the third port of the first medium-pressure three-way valve, The second port and the third port of the second medium-pressure three-way valve are connected, and the first port and the third port of the high-pressure three-way valve are connected.

Among them, it also includes a dehumidification mode, and the dehumidification mode includes:

closing the first shut-off valve and the second shut-off valve, communicating with the second port and the third port of the low-pressure three-way valve, and communicating with the first port and the third port of the first medium-pressure three-way valve, The second port and the third port of the second medium-pressure three-way valve are connected, and the first port and the second port of the high-pressure three-way valve are connected.

Among them, it also includes a defrosting mode, and the defrosting mode includes:

closing the first shut-off valve and the second shut-off valve, communicating with the second port and the third port of the low-pressure three-way valve, and communicating with the first port and the third port of the first medium-pressure three-way valve, The second port and the third port of the second medium-pressure three-way valve are connected, and the first port and the third port of the high-pressure three-way valve are connected.

The automobile heat pump system and its control method provided by the embodiments of the present invention, wherein the automobile heat pump system includes a first in-vehicle heat exchanger and a second in-vehicle heat exchanger installed in the air-conditioning duct of the automobile in sequence along the air supply direction, and further includes The compression unit, heating expansion valve and the first external heat exchanger installed outside the air-conditioning duct, the compression unit includes the first-stage compressor and the second-stage compressor; the outlet of the first external heat exchanger, the first-stage compression The machine, the first in-vehicle heat exchanger, the second-stage compressor, the second in-vehicle heat exchanger, the heating expansion valve and the inlet of the first out-of-vehicle heat exchanger are connected in sequence to form a heating cycle. The automotive heat pump system uses the first in-vehicle heat exchanger to cool the exhaust gas of the first-stage compressor of the compression unit, which can avoid the problem that the exhaust temperature of the compressor exceeds the limit under extreme low temperature conditions; The heat exchanger preheats the low-temperature air that has just entered the air-conditioning duct, effectively recovers the waste heat of the intercooler, increases the heating capacity in winter conditions, and can significantly improve the performance of the electric vehicle heat pump system under extreme low temperature conditions, effectively Improve the wide temperature range adaptability of the automotive heat pump system, and expand the application range of the automotive heat pump system to extremely cold areas.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a schematic structural view of an automobile heat pump system in an embodiment of the present invention;

Fig. 2 is a working flow chart of the automobile heat pump system in the heating mode in the embodiment of the present invention;

Fig. 3 is a working flow chart of the automobile heat pump system in the cooling mode in the embodiment of the present invention;

Fig. 4 is a working flow chart of the automobile heat pump system in the dehumidification mode in the embodiment of the present invention;

Fig. 5 is a working flow chart of the automobile heat pump system in the defrosting mode in the embodiment of the present invention;

Explanation of reference signs:

1: compression unit; 2: first external heat exchanger; 3: external fan;

4: The first in-vehicle heat exchanger; 5: The second in-vehicle heat exchanger; 6: Gas-liquid separator;

7: Second external heat exchanger; 8: Refrigeration expansion valve; 9: Regenerator;

10: High-pressure three-way valve; 11: Low-pressure three-way valve; 12: In-vehicle fan;

13: fresh air damper; 14: steering damper; 15: heating expansion valve;

16: The first medium pressure three-way valve; 17: The second medium pressure three-way valve; 18: The first cut-off valve;

19: second cut-off valve; 20: air-conditioning duct; 21: fresh air;

22: Return air; 23: Windshield air outlet; 24: Blowing surface air outlet;

25: Air outlet for blowing feet.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In the description of the embodiments of the present invention, it should be noted that, unless otherwise specified and limited, the terms "first" and "second" are for the purpose of clearly describing the numbering of product components and do not represent any substantial difference. The directions of "up", "down", "left" and "right" are all subject to the directions shown in the attached drawings. Those of ordinary skill in the art can understand the specific meanings of the above terms in the embodiments of the present invention according to specific situations.

It should be noted that, unless otherwise clearly stipulated and limited, the term "connection" should be interpreted in a broad sense, for example, it may be a direct connection or an indirect connection through an intermediary. Those of ordinary skill in the art can understand the specific meanings of the above terms in the embodiments of the invention in specific situations.

Fig. 1 is a schematic structural diagram of an automobile heat pump system in an embodiment of the present invention, and Fig. 2 is a work flow chart of the automobile heat pump system in an embodiment of the present invention in heating mode, as shown in Fig. 1 to Fig. 2 , the present invention An automobile heat pump system provided by an embodiment of the invention includes a first in-vehicle heat exchanger 4 and a second in-vehicle heat exchanger 5 installed sequentially in the air-conditioning air duct 20 of the automobile along the air supply direction, and also includes a heat pump installed in the air conditioner. The compression unit 1 outside the air duct 20, the heating expansion valve 15 and the first external heat exchanger 2, the compression unit 1 includes a first-stage compressor and a second-stage compressor, and the first-stage compressor on the right end is a low-pressure compressor. The second-stage compressor on the left is a high-pressure machine. The outlet of the first exterior heat exchanger 2, the first stage compressor, the first interior heat exchanger 4, the second stage compressor, the second interior heat exchanger 5, the heating expansion valve 15 and the first exterior The inlets of the heat exchangers 2 are connected in sequence to form a heating cycle.

Specifically, in this embodiment, the air supply direction is from right to left as an example for illustration, and the first in-vehicle heat exchanger 4 is located on the right side of the second in-vehicle heat exchanger 5 , closer to the air supply port. In the heating mode, both the first in-vehicle heat exchanger 4 and the second in-vehicle heat exchanger 5 function as coolers. The air intake in the air-conditioning duct 20 first exchanges heat with the first in-vehicle heat exchanger 4, the refrigerant gas in the first in-vehicle heat exchanger 4 cools down and releases heat, and the air intake outside the first in-vehicle heat exchanger 4 The wind is then preheated. Then the preheated incoming air exchanges heat with the second interior heat exchanger 5, and the incoming air is further heated into high-temperature air that can be used for heating, and finally sent to the user end to achieve the purpose of heating the car interior . The refrigerant can be R134a, R1234yf or CO ₂ and other refrigerants, and the refrigerant in this embodiment is carbon dioxide, a natural working substance.

As shown in Figure 2, the low-temperature and low-pressure refrigerant gas is compressed by the first-stage compressor of the compression unit 1 to become a medium-temperature and high-pressure gas, and then the exhaust gas of the first-stage compressor flows into the first The heat exchanger 4 in the car is cooled by the cold air that has just been sent into the air-conditioning duct 20, and becomes a low-temperature medium-pressure refrigerant gas. The low-temperature and medium-pressure refrigerant gas flows back to the compression unit 1 for the second compression, and is compressed into high-temperature and high-pressure refrigerant vapor by the second-stage compressor. The high-temperature and high-pressure refrigerant vapor discharged from the second-stage compressor flows into the second in-vehicle heat exchanger 5 installed in the air-conditioning air duct 20, and is preheated by the first in-vehicle heat exchanger 4 in the air-conditioning air duct 20. The air is cooled, and then flows through the heating expansion valve 15 to expand into a low-temperature and low-pressure gas-liquid two-phase refrigerant. Then the low-temperature and low-pressure refrigerant enters the first external heat exchanger 2, evaporates in the first external heat exchanger 2, undergoes a phase change, becomes a low-temperature and low-pressure refrigerant gas, and flows to the first-stage compression of the compression unit 1 again. machine to complete a refrigerant cycle.

An automobile heat pump system provided in this embodiment includes a first in-vehicle heat exchanger and a second in-vehicle heat exchanger installed sequentially in the air-conditioning air duct of the automobile along the air supply direction, and a compressor installed outside the air-conditioning air duct. unit, heating expansion valve and the first external heat exchanger, the compression unit includes the first stage compressor and the second stage compressor; the outlet of the first external heat exchanger, the first stage compressor, the first internal heat exchanger The heater, the second-stage compressor, the second in-vehicle heat exchanger, the heating expansion valve and the inlet of the first out-of-vehicle heat exchanger are connected in sequence to form a heating circulation loop. The automotive heat pump system uses the first in-vehicle heat exchanger to cool the exhaust gas of the first-stage compressor of the compression unit, which can avoid the problem that the exhaust temperature of the compressor exceeds the limit under extreme low temperature conditions; The heat exchanger preheats the low-temperature air that has just entered the air-conditioning duct, effectively recovers the waste heat of the intercooler, increases the heating capacity in winter conditions, and can significantly improve the performance of the electric vehicle heat pump system under extreme low temperature conditions, effectively Improve the wide temperature range adaptability of the automotive heat pump system, and expand the application range of the automotive heat pump system to extremely cold areas.

Further, as shown in FIGS. 1 to 2 , a second external heat exchanger 7 is also included, and the first interface (ie, the left end interface) of the second external heat exchanger 7 is connected to the first port through the first cut-off valve 18 . The inlet of the external heat exchanger 2 and the second interface (ie, the right end interface) of the second external heat exchanger 7 are connected to the outlet of the first external heat exchanger 2 through the second cut-off valve 19 . That is, the second exterior heat exchanger 7 is connected in parallel with the first exterior heat exchanger 2 .

Specifically, the first exterior heat exchanger 2 and the second exterior heat exchanger 7 can be placed side by side on the front of the vehicle. The working process when the second external heat exchanger 7 is put into the heating mode is basically the same as the above-mentioned embodiment, the difference is that the low-temperature and low-pressure refrigerant expanded by the heating expansion valve 15 is divided into two streams, and one part directly enters the The first external heat exchanger 2 performs heat exchange, and the other part flows into the second external heat exchanger 7 through the first cut-off valve 18 for heat exchange. After the evaporation phase transition in the second external heat exchanger 7 becomes low-temperature and low-pressure gaseous refrigerant, the second cut-off valve 19 through conduction recombines into a stream of fluid. By using the first external heat exchanger 2 and the second external heat exchanger 7 in parallel as an evaporator, the heat exchange area of the evaporator is effectively increased, the heat absorption of the evaporator is increased, and the performance of the winter working condition can be improved. Heating performance.

Furthermore, as shown in FIGS. 1 to 5 , it also includes a low-pressure three-way valve 11 , a first medium-pressure three-way valve 16 , a second medium-pressure three-way valve 17 , a high-pressure three-way valve 10 and a refrigeration expansion valve 8 .

The first port of the low-pressure three-way valve 11 (that is, the a port) is connected to the outlet of the first external heat exchanger 2, and the second port of the low-pressure three-way valve 11 (that is, the b-port) is connected to the inlet of the first-stage compressor , the third port (namely the c port) of the low-pressure three-way valve 11 is connected to the outlet of the first in-vehicle heat exchanger 4 . The refrigeration expansion valve 8 is arranged between the first port (ie port a) of the low-pressure three-way valve 11 and the inlet of the first in-vehicle heat exchanger 4 .

The first port (i.e., a port) of the first medium-pressure three-way valve 16 is connected to the outlet of the first-stage compressor, and the second port (i.e., b-port) of the first medium-pressure three-way valve 16 is connected to the first in-vehicle The inlet of the heat exchanger 4 and the third port (ie, the c port) of the first medium-pressure three-way valve 16 are connected to the second port (ie, the right end port) of the second external heat exchanger 7 .

The first interface (i.e. a interface) of the second medium pressure three-way valve 17 is connected to the outlet of the first in-vehicle heat exchanger 4, and the second interface (i.e. b interface) of the second medium pressure three-way valve 17 is connected to the first The inlet of the secondary compressor and the third port (namely the c port) of the second medium pressure three-way valve 17 are connected to the first port (ie the left end port) of the second external heat exchanger 7 .

The first interface (i.e., interface a) of the high-pressure three-way valve 10 is connected to the outlet of the second-stage compressor, and the second interface (i.e., interface b) of the high-pressure three-way valve is connected to the inlet of the second in-vehicle heat exchanger. The third port (namely, the c port) of the three-way valve is connected to the inlet of the first external heat exchanger.

Specifically, the low-pressure three-way valve 11 , the first medium-pressure three-way valve 16 , the second medium-pressure three-way valve 17 and the high-pressure three-way valve 10 can all use electric valves. By setting four three-way valves, the connection interface of the three-way valves can be switched in time according to different working conditions to meet the needs of users.

As shown in Figure 2, it is the working flow chart in the heating mode. At this time, both the first stop valve 18 and the second stop valve 19 are opened, the low-pressure three-way valve 11 is connected to ports a and b, and the first medium-pressure three-way The through valve 16 is connected to the ports a and b, the second medium-pressure three-way valve 17 is connected to the ports a and b, and the high-pressure three-way valve 10 is connected to the ports a and b.

As shown in Figure 3, it is the working flow chart in cooling mode. At this time, both the first shut-off valve 18 and the second shut-off valve 19 are closed, the low-pressure three-way valve 11 is connected to ports b and c, and the first medium-pressure three-way The valve 16 is connected to ports a and c, the second medium-pressure three-way valve 17 is connected to ports b and c, and the high-pressure three-way valve 10 is connected to ports a and c.

As shown in Figure 4, it is the work flow chart in the dehumidification mode. At this time, the first stop valve 18 and the second stop valve 19 are closed, the low-pressure three-way valve 11 is connected to the b and c ports, and the first medium-pressure three-way The valve 16 is connected to ports a and c, the second medium-pressure three-way valve 17 is connected to ports b and c, and the high-pressure three-way valve 10 is connected to ports a and b.

As shown in Figure 5, it is the work flow chart in the defrosting mode. At this time, both the first stop valve 18 and the second stop valve 19 are closed, the low-pressure three-way valve 11 is connected to ports b and c, and the first medium-pressure three-way The through valve 16 is connected to ports a and c, the second medium-pressure three-way valve 17 is connected to ports b and c, and the high-pressure three-way valve 10 is connected to ports a and c.

Further, as shown in FIG. 3 , a regenerator 9 is also included, and the first heat exchange side (left passage) of the regenerator 9 is connected in series with the outlet of the first in-vehicle heat exchanger 4 and the low-pressure three-way valve 11 Between the third interface (i.e. c interface) of the regenerator 9, the second heat exchange side (right side passage) of the regenerator 9 is connected in series between the refrigeration expansion valve 8 and the first interface (i.e. a interface) of the low pressure three-way valve 11 Between, that is, the second heat exchange side of the regenerator 9 is connected in series between the refrigeration expansion valve 8 and the outlet of the first external heat exchanger 2 .

Specifically, in cooling mode, the regenerator 9 is put into use. As shown in Figure 3, the exhaust gas of the first-stage compressor of the compression unit 1 communicates with the second external heat exchanger 7 through the first medium-pressure three-way valve 16 and the second medium-pressure three-way valve 17, and the refrigerant passes through the first medium-pressure three-way valve 17. After being compressed by the first-stage compressor, it reaches a high-temperature and medium-pressure state; after being cooled by the second external heat exchanger 7, the low-temperature and medium-pressure gas flows into the second-stage compressor, and becomes high-temperature after being compressed by the second-stage compressor. High-pressure gas; the high-temperature and high-pressure gas discharged from the second-stage compressor flows to the first external heat exchanger 2, and is cooled by the air blown by the external fan 3 to become a low-temperature high-pressure liquid, and then enters the regenerator 9 is further cooled to reach a lower temperature; it becomes a low-temperature and low-pressure two-phase fluid after throttling by the refrigeration expansion valve 8, and then evaporates in the first in-vehicle heat exchanger 4 to absorb the heat of the air in the air-conditioning duct. The purpose of cooling the car compartment is achieved. Wherein, the temperature of the first heat exchange side in the regenerator 9 is lower than the temperature of the second heat exchange side, so that the refrigerant in the first heat exchange side of the regenerator 9 can be precooled to reduce the The temperature before throttling and the dryness after throttling increase the cooling capacity and improve the cooling effect.

The second external heat exchanger 7 installed at the front of the vehicle intercools the exhaust gas of the first-stage compressor of the compression unit 1 to reduce the exhaust temperature of the compression unit 1 and ensure the high pressure ratio working condition in an extremely high temperature environment The safe use of the lower compression unit 1 broadens the applicability of the automotive heat pump system to high-temperature refrigeration conditions.

More specifically, since the first exterior heat exchanger 2 and the second exterior heat exchanger 7 are arranged side by side, the exterior fan 3 can operate the first exterior heat exchanger 2 and the second exterior heat exchanger 7 at the same time. Allow to cool.

Further, as shown in Figure 1, it also includes a gas-liquid separator 6, the inlet of the gas-liquid separator 6 is connected to the second port (i.e. b port) of the low-pressure three-way valve 11, and the outlet of the gas-liquid separator 6 is connected to Inlet for first stage compressor. By setting the gas-liquid separator 6, the gas and the liquid can be separated as far as possible, so as to prevent the liquid from entering the compression unit 1 and damaging the compressor.

Further, as shown in FIG. 1 , it also includes an exterior fan 3 installed outside the air-conditioning duct 20 , and the air outlet of the exterior fan 3 faces the first exterior heat exchanger 2 .

Further, as shown in FIG. 1 , it also includes an in-vehicle fan 12 installed in the air-conditioning duct 20, and the in-vehicle fan 12 is installed on the right side of the first in-vehicle heat exchanger 4, so as to deliver cold air from right to left . Fan 12 in the car and fan 3 outside the car all can adopt electric fan.

Further, as shown in FIG. 1 , it also includes a fresh air damper 13 installed at the inlet of the air-conditioning duct 20, and the fresh air damper 13 can be used to select whether the fresh air 21 or the return air 22 is blown in, so as to carry out fresh air circulation or vehicle ventilation. Internal self-circulation.

Further, as shown in FIG. 1 , it also includes a windshield air outlet 23 installed at the outlet of the air-conditioning duct 20, a blowing surface air outlet 24 and a foot blowing air outlet 25, wherein the windshield air outlet 23 faces upwards, For blowing air to the windshield place in front of the car; Blowing surface air outlet 24 toward the middle, for sending air to the driver's face; Blowing foot air outlet 25 downwards, for sending air to the driver's feet.

Furthermore, as shown in FIG. 1 , it also includes a directional air valve 14 installed between the first in-vehicle heat exchanger 4 and the second in-vehicle heat exchanger 5 for adjusting the wind direction. Direction adjustment damper 14 and fresh air damper 13 all can adopt electric valve.

As shown in Figure 2, an embodiment of the present invention also provides a control method for an automobile heat pump system. The automobile heat pump system adopts the above-mentioned automobile heat pump system. The control method includes a heating mode, and the heating mode includes: connecting to the first external heat exchanger 2, the first-stage compressor, the first in-vehicle heat exchanger 4, the second-stage compressor, the second in-vehicle heat exchanger 5, the heating expansion valve 15 and the inlet of the first out-vehicle heat exchanger 2.

Further, as shown in Figure 2, the heating mode also includes:

Open the first shut-off valve 18 and the second shut-off valve 19, communicate with the a, b ports of the low-pressure three-way valve 11, communicate with the a, b ports of the first medium-pressure three-way valve 16, and communicate with the ports of the second medium-pressure three-way valve 17 The ports a and b are connected to the ports a and b of the high-pressure three-way valve 10 .

Further, as shown in Figure 3, it also includes a cooling mode, and the cooling mode includes:

Close the first shut-off valve 18 and the second shut-off valve 19, communicate with the b, c ports of the low-pressure three-way valve 11, communicate with the a, c ports of the first medium-pressure three-way valve 16, and communicate with the ports of the second medium-pressure three-way valve 17 Ports b and c are connected to ports a and c of the high-pressure three-way valve 10 .

Further, as shown in Figure 4, it also includes a dehumidification mode, and the dehumidification mode includes:

Close the first shut-off valve 18 and the second shut-off valve 19, communicate with the b, c ports of the low-pressure three-way valve 11, communicate with the a, c ports of the first medium-pressure three-way valve 16, and communicate with the ports of the second medium-pressure three-way valve 17 Ports b and c are connected to ports a and b of the high-pressure three-way valve 10 .

Specifically, the refrigerant becomes a low-temperature and low-pressure two-phase fluid after being throttled by the refrigeration expansion valve 8, and then evaporates and absorbs heat in the first in-vehicle heat exchanger 4, so that the temperature of the outer surface of the first in-vehicle heat exchanger 4 is Reach a lower state; after the refrigerant evaporates and absorbs heat, it becomes a low-temperature and low-pressure steam, passes through the regenerator 9 and the gas-liquid separator 6, and then flows into the compression unit 1, and is then compressed into a high-temperature and medium-pressure gas state by the first-stage compressor; The high-pressure refrigerant is cooled by the second external heat exchanger 7 to become a low-temperature and medium-pressure gas, and then flows into the second-stage compressor. Heater 5, after being cooled by the air in air-conditioning duct 20, flows into the first external heat exchanger 2 to be further cooled; then flows to regenerator 9 and refrigeration expansion valve 8, completing a cycle. The air with higher humidity blown in by the in-vehicle fan 12 in the air-conditioning duct 20 flows through the surface of the first in-vehicle heat exchanger 4 with lower temperature, and the humidity decreases while being cooled; then the air with low temperature and low humidity flows through The second heat exchanger 5 in the car is heated to air with higher temperature and lower humidity, and then sent to the car compartment, so as to achieve the purpose of dehumidifying the car room air.

Further, as shown in Figure 5, it also includes a defrosting mode, and the defrosting mode includes:

Close the first shut-off valve 18 and the second shut-off valve 19, communicate with the b, c ports of the low-pressure three-way valve 11, communicate with the a, c ports of the first medium-pressure three-way valve 16, and communicate with the ports of the second medium-pressure three-way valve 17 Ports b and c are connected to ports a and c of the high-pressure three-way valve 10 . The flow direction of the refrigerant in the defrosting mode is the same as that in the cooling mode, and the exhaust gas of the first-stage compressor and the exhaust gas of the second-stage compressor of the compression unit 1 are respectively used for the second external heat exchanger 7 Heating with the first external heat exchanger 2, so that the frost layer attached to the surface of the second external heat exchanger 7 and the first external heat exchanger 2 gradually melts, thereby achieving the purpose of defrosting. This mode is mainly used in winter conditions. After using the heating mode for a period of time, defrost by enabling the defrost mode to avoid affecting the heat transfer performance of the heat exchanger, so that the system can maintain high-efficiency operation for a long time.

It can be seen from the above embodiments that the automobile heat pump system and its control method provided by the present invention, wherein the automobile heat pump system includes a first in-vehicle heat exchanger and a second in-vehicle heat exchanger sequentially installed in the air-conditioning duct of the automobile along the air supply direction. The heat exchanger also includes a compression unit installed outside the air-conditioning duct, a heating expansion valve and a first external heat exchanger, the compression unit includes a first-stage compressor and a second-stage compressor; the first external heat exchanger The outlet, the first-stage compressor, the first in-vehicle heat exchanger, the second-stage compressor, the second in-vehicle heat exchanger, the heating expansion valve and the inlet of the first out-of-vehicle heat exchanger are connected in sequence to form a heating loop loop. The automotive heat pump system uses the first in-vehicle heat exchanger to cool the exhaust gas of the first-stage compressor of the compression unit, which can avoid the problem that the exhaust temperature of the compressor exceeds the limit under extreme low temperature conditions; The heat exchanger preheats the low-temperature air that has just entered the air-conditioning duct, effectively recovers the waste heat of the intercooler, increases the heating capacity in winter conditions, and can significantly improve the performance of the electric vehicle heat pump system under extreme low temperature conditions, effectively Improve the wide temperature range adaptability of the automotive heat pump system, and expand the application range of the automotive heat pump system to extremely cold areas.

Furthermore, the electric vehicle heat pump system provided by the present invention takes into account the performance of cooling and heating conditions, and can significantly improve the performance of the electric vehicle heat pump system under extreme high temperature conditions and extremely low temperature conditions.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims (10)

1. a kind of automobile heat pump system, including the first interior heat exchange in the air-conditioning duct that air supply direction is successively installed on automobile Device and the second interior heat exchanger, which is characterized in that further include the compression unit being installed on outside the air-conditioning duct, heating expansion valve With the first vehicle external heat exchanger, the compression unit includes first order compressor and high stage compressor；It exchanges heat outside first vehicle The outlet of device, the first order compressor, the first interior heat exchanger, the high stage compressor, second car change The import of hot device, the heating expansion valve and the first vehicle external heat exchanger is sequentially connected, to form heating circulation loop.

2. automobile heat pump system according to claim 1, which is characterized in that it further include the second vehicle external heat exchanger, described The first interface of two vehicle external heat exchangers is connected to the import of the first vehicle external heat exchanger, second vehicle by the first shut-off valve The second interface of external heat exchanger is connected to the outlet of the first vehicle external heat exchanger by the second shut-off valve.

3. automobile heat pump system according to claim 2, which is characterized in that further include low pressure triple valve, press three in first Port valve presses triple valve, Triple Valve with High Pressure and refrigeration expansion valve in second；

The first interface of the low pressure triple valve is connected to the outlet of the first vehicle external heat exchanger, and the of the low pressure triple valve Two interfaces are connected to the import of the first order compressor, and it is interior that the third interface of the low pressure triple valve is connected to described first The outlet of heat exchanger；The refrigeration expansion valve is set to the import of the first interface and the first interior heat exchanger of the low pressure triple valve Between；

It presses the first interface of triple valve to be connected to the outlet of the first order compressor in described first, presses threeway in described first The second interface of valve is connected to the import of the described first interior heat exchanger, presses the third interface of triple valve to be connected in described first The second interface of the second vehicle external heat exchanger；

It presses the first interface of triple valve to be connected to the outlet of the described first interior heat exchanger in described second, presses three in described second The second interface of port valve is connected to the import of the high stage compressor, presses the third interface of triple valve to be connected in described second The first interface of the second vehicle external heat exchanger；

The first interface of the Triple Valve with High Pressure is connected to the outlet of the high stage compressor, and the second of the Triple Valve with High Pressure Interface is connected to the import of the described second interior heat exchanger, and the third interface of the Triple Valve with High Pressure is connected to outside first vehicle The import of heat exchanger.

4. automobile heat pump system according to claim 3, which is characterized in that it further include regenerator, the of the regenerator Between the outlet of one the described first interior heat exchanger of heat exchange side series connection access and the third interface of the low pressure triple valve, described time Second heat exchange side series connection of hot device accesses between the refrigeration expansion valve and the first interface of the low pressure triple valve.

5. automobile heat pump system according to claim 3, which is characterized in that it further include gas-liquid separator, the gas-liquid point From the second interface that the import of device is connected to the low pressure triple valve, the outlet of the gas-liquid separator is connected to the first order The import of compressor.

6. a kind of control method of automobile heat pump system, which is characterized in that the automobile heat pump system use as claim 1 to Automobile heat pump system described in any one of 5, the control method include heating mode, and the heating mode includes: connection institute State the outlet of the first vehicle external heat exchanger, the first order compressor, the first interior heat exchanger, the high stage compressor, The import of described second interior heat exchanger, the heating expansion valve and the first vehicle external heat exchanger.

7. control method according to claim 6, which is characterized in that the heating mode includes:

The first shut-off valve and the second shut-off valve are opened, the first interface and second interface of low pressure triple valve are connected to, is connected in first The first interface and second interface of triple valve are pressed, the first interface and second interface of triple valve are pressed in connection second, is connected to high pressure The first interface and second interface of triple valve.

8. control method according to claim 7, which is characterized in that further include refrigeration mode, the refrigeration mode includes:

First shut-off valve and second shut-off valve are closed, the second interface and third for being connected to the low pressure triple valve connect Mouthful, the first interface and third interface of triple valve are pressed in connection described first, press the second of triple valve to connect in connection described second Mouth and third interface, are connected to the first interface and third interface of the Triple Valve with High Pressure.

9. control method according to claim 8, which is characterized in that further include dehumidification mode, the dehumidification mode includes:

First shut-off valve and second shut-off valve are closed, the second interface and third for being connected to the low pressure triple valve connect Mouthful, the first interface and third interface of triple valve are pressed in connection described first, press the second of triple valve to connect in connection described second Mouth and third interface, are connected to the first interface and second interface of the Triple Valve with High Pressure.

10. control method according to claim 7, which is characterized in that it further include defrosting mode, the defrosting mode packet It includes:

First shut-off valve and second shut-off valve are closed, the second interface and third for being connected to the low pressure triple valve connect Mouthful, the first interface and third interface of triple valve are pressed in connection described first, press the second of triple valve to connect in connection described second Mouth and third interface, are connected to the first interface and third interface of the Triple Valve with High Pressure.