An electric vehicle heat pump air conditioning system

Abstract

The application provides an electric vehicle heat pump air conditioning system, and belongs to the technical field of electric vehicle heat pump air conditioning, and comprises: a charge compressor for driving refrigerant; a four-way reversing valve comprising four channel ports a, b, c and d which are switched and communicated with each other, wherein the a port is connected with the output end of the charge compressor, and the c port is connected with the input end of the charge compressor; a first expansion valve, the output end of which is connected with the d port of the four-way reversing valve; a second expansion valve, the output end of which is connected with the b port of the four-way reversing valve; an ejector, the gaseous refrigerant in the output of which is input into the charge port of the charge compressor; the output liquid-phase refrigerant of which is output after throttling through the second expansion valve; and a supercooler for heat exchange of the refrigerant. The system can reduce the throttling loss of the electric vehicle air conditioner in refrigeration and heating, and reduce the compressor pressure ratio.

Description

Technical Field

[0001] This invention belongs to the field of electric vehicle heat pump air conditioning technology, and specifically relates to an electric vehicle heat pump air conditioning system. Background Technology

[0002] In recent years, with the rapid development of my country's electric vehicle industry, energy conservation in electric vehicles has become a hot topic in the automotive air conditioning field. The energy efficiency level of electric vehicle air conditioning systems is a key factor affecting the cruising range of electric vehicles, and continuously improving the performance of automotive air conditioning is crucial to implementing my country's dual-carbon policy.

[0003] In particular, when the car's air conditioning is running in cold regions, the heat pump mode suffers from severe cooling capacity reduction, excessive compressor pressure ratio, and excessively high exhaust temperatures. Activating the electric auxiliary heater further reduces energy efficiency, significantly decreasing driving range. Furthermore, in hot summer weather, increased exhaust pressure leads to excessive throttling losses in the traditional throttling mechanism, resulting in a significant decrease in cooling performance.

[0004] Existing methods for reducing throttling losses in refrigeration systems generally employ regenerators or mechanical subcooling. However, these technologies cannot effectively address the problem of excessive throttling losses under harsh operating conditions. Summary of the Invention

[0005] To overcome the shortcomings of the existing technology, the present invention provides a heat pump air conditioning system for electric vehicles.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] An electric vehicle heat pump air conditioning system includes:

[0008] A refrigerant compressor is used to drive the refrigerant.

[0009] The four-way reversing valve includes four interconnected channels a, b, c, and d, where channel a is connected to the output of the gas supply compressor and channel c is connected to the input of the gas supply compressor.

[0010] The first expansion valve has its output end connected to port d of the four-way directional valve;

[0011] The second expansion valve has its output end connected to port b of the four-way directional valve;

[0012] The injector, whose input end is connected to the input ends of the first expansion valve and the second expansion valve, is used to inject refrigerant. The gaseous refrigerant in the refrigerant it outputs is input into the gas injection port of the gas injection compressor, and the liquid refrigerant in the refrigerant it outputs is output after being throttled by the third expansion valve.

[0013] The subcooler includes two subcooling circuits. One subcooling circuit is used to input the refrigerant output after throttling by the third expansion valve into the ejector inlet. The other subcooling circuit connects the input end of the second expansion valve and the input end of the first expansion valve.

[0014] When the refrigerant flows from the second expansion valve side to the first expansion valve side or from the first expansion valve side to the second expansion valve side, the refrigerant exchanges heat with the refrigerant from the third expansion valve in the subcooler.

[0015] Furthermore, it also includes:

[0016] The first valve is connected in parallel with the first expansion valve; the second valve is connected in parallel with the second expansion valve.

[0017] Furthermore, the output end of the injector is provided with a first gas-liquid separator, which is used to input the gas phase refrigerant in the refrigerant injected by the injector into the gas injection port of the gas injection compressor, and to output the liquid phase refrigerant in the refrigerant injected by the injector into the third expansion valve.

[0018] Furthermore, it also includes:

[0019] The second gas-liquid separator is located on the connection line between port C of the four-way reversing valve and the gas replenishment compressor.

[0020] The regenerator includes two heat exchange circuits, one of which connects the first gas-liquid separator and the third expansion valve, and the other heat exchange circuit connects the C port of the four-way reversing valve to the input end of the second gas-liquid separator.

[0021] Furthermore, it also includes:

[0022] The third valve is located on the connection line between the injector and the first expansion valve.

[0023] Furthermore, it also includes:

[0024] The first indoor heat exchanger is located on the connection line between port d of the four-way reversing valve and the first expansion valve.

[0025] The second indoor heat exchanger is located on the connection line between the third expansion valve and the subcooler.

[0026] The outdoor heat exchanger is located on the connection line between the second expansion valve and the four-way reversing valve at port b.

[0027] Furthermore, the first indoor heat exchanger, the second indoor heat exchanger, and the outdoor heat exchanger are microchannel heat exchangers;

[0028] Furthermore, the injector is an adjustable injector with a built-in valve needle or an adjustable injector with multiple injectors.

[0029] The electric vehicle heat pump air conditioning system provided by this invention has the following beneficial effects:

[0030] In heat pump mode, the ad channel of the four-way reversing valve 102 is connected, and the bc channel is connected; the first expansion valve 104 is closed; the first valve 105 is open; at this time, the refrigerant flows from the first expansion valve side to the third expansion valve side.

[0031] In cooling mode, the ab channels of the four-way reversing valve 102 are connected, and the dc channel is connected; the second expansion valve 109 is closed; the first valve 105 is closed; at this time, the refrigerant flows from the third expansion valve side to the first expansion valve side.

[0032] When the refrigerant flows from the second expansion valve to the first expansion valve or from the first expansion valve to the second expansion valve, the refrigerant exchanges heat with the refrigerant from the third expansion valve in the subcooler. This invention utilizes the subcooler to reduce the inlet temperature of the refrigerant entering the first or second expansion valve, thereby reducing throttling losses. Furthermore, the refrigerant from the third expansion valve is heated and becomes a superheated gaseous refrigerant after passing through the subcooler, and then enters the ejector; the gas in the two-phase refrigerant produced at the ejector outlet is fed into the compressor's gas supply port, reducing the compressor's specific work and discharge temperature simultaneously, thereby further reducing the system's throttling losses. Attached Figure Description

[0033] To more clearly illustrate the embodiments and design schemes of the present invention, the accompanying drawings required for this embodiment will be briefly described below. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of an electric vehicle heat pump air conditioning system coupled with injector and gas replenishment enthalpy enhancement in an embodiment of the present invention in heat pump mode;

[0035] Figure 2 Ph diagram of the electric vehicle heat pump air conditioning system in heat pump mode according to an embodiment of the present invention, where the injector and the gas replenishment enthalpy enhancement coupling are coupled;

[0036] Figure 3 This is a schematic diagram of an electric vehicle heat pump air conditioning system coupled with injector and gas replenishment enthalpy enhancement in dehumidification mode according to an embodiment of the present invention.

[0037] Figure 4 This is a schematic diagram of an electric vehicle heat pump air conditioning system coupled with injector and gas replenishment enthalpy enhancement in an embodiment of the present invention in heat pump defrosting mode;

[0038] Figure 5This is a schematic diagram of an electric vehicle heat pump air conditioning system coupled with injector and enthalpy boosting in an embodiment of the present invention in cooling mode. Detailed Implementation

[0039] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0040] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "connected" or "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. In the description of this invention, unless otherwise stated, "a plurality of" means two or more, which will not be elaborated further here.

[0041] Example:

[0042] This invention provides a heat pump air conditioning system for electric vehicles, specifically as follows: Figure 1As shown, it includes: a gas-fuel compressor 101 for driving refrigerant; a four-way reversing valve 102, which includes four interconnected ports a, b, c, and d, wherein port a is connected to the output of the gas-fuel compressor 101, and port c is connected to the input of the gas-fuel compressor 101; a first expansion valve 104, the output of which is connected to port d of the four-way reversing valve 102; a first valve 105, connected in parallel with the first expansion valve 104; a second expansion valve 109, the output of which is connected to port b of the four-way reversing valve 102; a second valve 108, connected in parallel with the second expansion valve 109; and an injector 106, the input of which is connected to the input of the first expansion valve 104 and the second expansion valve 109, for injecting refrigerant out; its output... The gaseous refrigerant in the output refrigerant is input into the gas supply port of the gas supply compressor 101; the liquid refrigerant in the output refrigerant is output after being throttled by the third expansion valve 112; the subcooler 107 includes two subcooling circuits, one of which is used to input the refrigerant output after being throttled by the third expansion valve 112 into the ejector inlet of the ejector 106; the other subcooling circuit connects the input end of the second expansion valve 109 and the input end of the first expansion valve 104; when the refrigerant flows from the second expansion valve 109 side to the first expansion valve 104 side or from the first expansion valve 104 side to the second expansion valve 109 side, the refrigerant exchanges heat with the refrigerant from the third expansion valve 112 in the subcooler 107.

[0043] Specifically, the output end of the ejector 106 is provided with a first gas-liquid separator 117. The first gas-liquid separator 117 is used to input the gas phase refrigerant in the refrigerant ejected by the ejector 106 into the gas supply port of the gas supply compressor 101, and to output the liquid phase refrigerant in the refrigerant ejected by the ejector 106 into the third expansion valve 112.

[0044] The gas in the two-phase refrigerant generated at the output port of ejector 106 passes through the gas phase port of the first gas-liquid separator 117 and is fed into the gas supply port of compressor 101. This reduces the specific work of the compressor and also lowers the compressor discharge temperature.

[0045] Specifically, it also includes: a second gas-liquid separator 116, which is located on the connection line between port c of the four-way reversing valve 102 and the gas supply compressor 101; and a regenerator 113, which includes two heat exchange circuits, one of which connects the first gas-liquid separator 117 and the third expansion valve 112, and the other heat exchange circuit connects port c of the four-way reversing valve 102 and the input end of the second gas-liquid separator 116.

[0046] Specifically, it also includes:

[0047] The first indoor heat exchanger 103 is located on the connection line between the d port of the four-way reversing valve 102 and the first expansion valve 104; the second indoor heat exchanger 111 is located on the connection line between the third expansion valve 112 and the subcooler 107, and the second indoor heat exchanger 111 is equipped with a damper 114; the outdoor heat exchanger 110 is located on the connection line between the second expansion valve 109 and the b port of the four-way reversing valve 102.

[0048] The ejector is used to recover the medium-pressure refrigerant ejected from the second indoor heat exchanger 111 through expansion work. The gaseous refrigerant in the refrigerant output from the ejector is fed into the gas supply port of the gas supply compressor 101. The liquid refrigerant ejected from the ejector passes through the third expansion valve 112 to throttle the pressure drop, and the latent heat of vaporization generated is absorbed in the second indoor evaporator 111 and subcooler 107. The liquid or gaseous refrigerant from the second indoor heat exchanger 111 is heated into superheated gaseous refrigerant after passing through the subcooler 107, and then enters the ejector 106. The latent heat of the liquid refrigerant at the outlet of the ejector 106 is absorbed in the second indoor heat exchanger 111 or subcooler 107, which can provide the cooling load required for demisting and reduce throttling losses.

[0049] The first indoor heat exchanger 103, the second indoor heat exchanger 111, and the outdoor heat exchanger 110 are microchannel heat exchangers; the ejector 106 is an adjustable ejector with a built-in valve needle or an adjustable ejector with multiple ejectors.

[0050] The system can achieve four modes: heat pump, cooling, heating and dehumidification, and defrosting by switching the flow channels of the four-way reversing valve 102, switching the solenoid valves 105 and 115, and switching the built-in damper 114 in the air duct.

[0051] The following are embodiments of the present invention:

[0052] Example 1:

[0053] Figure 1The diagram illustrates the operating flow of the system in heat pump mode: the ad channel and bc channel of the four-way reversing valve 102 are connected; the first expansion valve 104 is closed; the first valve 105 is open; the damper 114 of the second indoor heat exchanger 111 is closed; the refrigerant is compressed sequentially by the compressor 101, enters the first indoor heat exchanger 103 to release heat through the ad channel of the four-way reversing valve 102, and then enters the first valve 105, splitting into two paths: one path involves the refrigerant passing through the subcooler 107, the second expansion valve 109, the outdoor heat exchanger 110, and the four-way reversing valve. The refrigerant flows through channel bc, regenerator 113, second gas-liquid separator 116, and then back to compressor suction port; another refrigerant, through third valve 115, nozzle of ejector 106, is injected into subcooler 1073 channel, mixed and pressurized, and enters first gas-liquid separator 117 in two-phase state; gaseous refrigerant flowing out of first gas-liquid separator 117 enters compressor injection port, and liquid refrigerant sequentially passes through third expansion valve 112 and second indoor heat exchanger 111, and then through subcooler 107 back to ejector inlet of ejector 106.

[0054] Figure 2This is a pressure-enthalpy diagram (ph diagram) showing the system's operation in heat pump mode. The specific working process is as follows: Refrigerant 1 is pre-compressed by compressor 101, and then mixes with saturated gas 5 from the first gas-liquid separator 117 to become superheated gas 2. It is then further compressed to become high-pressure superheated gas 3. After releasing heat in the internal heat exchanger 103, it becomes saturated or subcooled liquid, splitting into two paths: One path involves refrigerant passing through cooler 107 to further increase its subcooling 6, then passing through the second expansion valve 109 to become a two-phase state 7, and absorbing heat in the outdoor heat exchanger 110 to become saturated gas 8. It then passes through the four-way reversing valve 102 and connecting pipes to absorb heat, becoming superheated gas 9, entering the regenerator 113 for further superheating 10, and then returning to the compressor suction port through the second gas-liquid separator 116; the other path involves refrigerant passing through the third valve 115 and the nozzle of ejector 106 to become a supersonic gas-liquid two-phase state 11', converting pressure energy into kinetic energy, and being ejected to the subcooler 107. The refrigerant at point 18 in channel 1073 is repeatedly mixed at point 12, and then, after diffusion, enters the first gas-liquid separator 117 in a two-phase state at point 13. The gaseous refrigerant flowing out of the first gas-liquid separator 117 at point 5 enters the compressor's gas supply port. The liquid refrigerant at point 14 passes through the regenerator 113 for subcooling at point 15, and then enters the third expansion valve 112 for isoenthalpic expansion, becoming a two-phase state at point 16. With the damper of the second indoor heat exchanger 111 closed, and ignoring heat leakage losses, the two-phase refrigerant at point 17 enters the subcooler 107 to absorb heat and become superheated gas at point 18, then returns to the ejector inlet of ejector 106. During this process, ejector 106 recovers some expansion work, increases the gas supply pressure, and reduces the compressor's specific power. Simultaneously, the latent heat of the refrigerant generated by throttling is recovered in the subcooler 107, effectively increasing the subcooling degree, reducing throttling losses, and increasing the enthalpy difference of the refrigerant in the outdoor heat exchanger 110, thereby comprehensively improving the system's low-temperature heating performance.

[0055] Example 2:

[0056] Figure 3The diagram illustrates the operating flow of the system in dehumidification mode. The ad channel and bc channel of the four-way reversing valve 102 are connected; the expansion valve 104 is closed, and the first valve 105 is open; the damper 114 is open; the refrigerant is compressed sequentially by the compressor 101, passes through the ad channel of the four-way reversing valve 102, enters the first indoor heat exchanger 103 to release heat, then enters the first valve 105, and then splits into two paths: one path involves the refrigerant passing through the subcooler 107, the second expansion valve 109, the outdoor heat exchanger 110, the bc channel of the four-way reversing valve, the regenerator 113, and the second gas-liquid separator. The refrigerant flows through the first gas-liquid separator 116 and then back to the compressor suction port. Another refrigerant path passes through the third valve 115 and the nozzle of the ejector 106, drawing refrigerant from channel 1073 of the subcooler 107. After mixing and pressurization, the refrigerant enters the first gas-liquid separator 117 in a two-phase state. The gaseous refrigerant flowing out of the first gas-liquid separator 117 enters the compressor's gas supply port, while the liquid refrigerant passes sequentially through the third expansion valve 112 and the second indoor heat exchanger 111, then returns to the ejector inlet of the ejector 106 via the subcooler 107. Humid air condenses and dehumidifies as it passes through the second indoor heat exchanger 111, and its temperature rises after passing through the first indoor heat exchanger 103, achieving the purpose of heating and dehumidification. Simultaneously, the outdoor heat exchanger 110 operates normally, absorbing heat from the air, ensuring that the heating capacity remains constant during dehumidification.

[0057] Example 3:

[0058] Specifically, it also includes: a third valve 115, which is located on the connection line between the injector 106 and the first expansion valve 104.

[0059] Figure 4 The diagram illustrates the defrosting operation of the system of the present invention. In this mode, the ab and cd channels of the four-way reversing valve 102 are connected; the first expansion valve 104 and the second expansion valve 109 are closed; the damper 114 of the indoor heat exchanger 111 is closed; the first valve 105 is open, and the third valve 115 is closed; the refrigerant is compressed sequentially by the compressor 101, enters the outdoor heat exchanger 110 for defrosting through the ab and c channels of the four-way reversing valve 102, and then passes through the one-way valve 108, the subcooler 107, the first valve 105, the first indoor heat exchanger 103, the dc channel of the four-way reversing valve, the regenerator 113, and the second gas-liquid separator 116. The liquid is stored at the bottom to prevent liquid slugging, and the gas returns to the compressor suction port. At this time, the third valve 115 is closed, the ejector drive circuit stops working, and the compressor refueling mode is turned off.

[0060] Example 4:

[0061] Figure 5The diagram illustrates the system's operation in cooling mode. In this mode, under cooling conditions, the ab and b channels of the four-way reversing valve 102 are connected, and the dc channel is connected; the second expansion valve 109 is closed; the first valve 105 is closed; and the damper 114 is closed. The refrigerant is compressed sequentially by the compressor 101, passes through the ab and b channels of the four-way reversing valve 102 to enter the outdoor heat exchanger 110 to release heat, and then passes through the one-way valve 108 and the subcooler 107, before splitting into two paths: one path involves the refrigerant passing through the first expansion valve 104, the first indoor heat exchanger 103, and the dc channel of the four-way reversing valve 102. The refrigerant flows through channel C, regenerator 113, second gas-liquid separator 116, and then back to the suction port of compressor 101. Another refrigerant path passes through third valve 115, nozzle of ejector 106, and is injected into channel 1073 of subcooler 107. After mixing and pressurization, it enters the first gas-liquid separator 117 in a two-phase state. The gaseous refrigerant flowing out of the first gas-liquid separator 117 enters the compressor's gas supply port, while the liquid refrigerant passes sequentially through third expansion valve 112 and second indoor heat exchanger 111, then through subcooler 107 and back to the ejector inlet of ejector 106. In this mode, the system can still maintain a moderate compressor discharge temperature under high ambient temperatures while increasing cooling capacity, thus enhancing the multi-condition adaptability of automotive air conditioning.

[0062] The above-described embodiments are merely preferred embodiments of the present invention, and the scope of protection of the present invention is not limited thereto. Any simple changes or equivalent substitutions of the technical solutions that can be obviously obtained by those skilled in the art within the scope of the technology disclosed in the present invention shall fall within the scope of protection of the present invention.

Claims

1. A heat pump air conditioning system for electric vehicles, characterized in that, include: The gas-fuel compressor (101) is used to drive the refrigerant; The four-way reversing valve (102) includes four interconnected channels a, b, c, and d, wherein channel a is connected to the output of the gas supply compressor (101) and channel c is connected to the input of the gas supply compressor (101). The first expansion valve (104) has its output end connected to port d of the four-way directional valve (102); The second expansion valve (109) has its output end connected to port b of the four-way directional valve (102); The injector (106) has its input end connected to the input ends of the first expansion valve (104) and the second expansion valve (109) for injecting refrigerant. The gaseous refrigerant in the refrigerant it outputs is input into the gas supply port of the gas supply compressor (101), and the liquid refrigerant in the refrigerant it outputs is output after being throttled by the third expansion valve (112). The subcooler (107) includes two subcooling circuits, one of which is used to input the refrigerant output after throttling by the third expansion valve (112) into the ejector inlet of the ejector (106), and the other subcooling circuit connects the input end of the second expansion valve (109) and the input end of the first expansion valve (104). When the refrigerant flows from the side of the second expansion valve (109) to the side of the first expansion valve (104) or from the side of the first expansion valve (104) to the side of the second expansion valve (109), the refrigerant exchanges heat with the refrigerant from the third expansion valve (112) in the subcooler (107); The output end of the injector (106) is provided with a first gas-liquid separator (117). The first gas-liquid separator (117) is used to input the gas phase refrigerant in the refrigerant injected by the injector (106) into the gas supply port of the gas supply compressor (101) and output the liquid phase refrigerant in the refrigerant injected by the injector (106) into the third expansion valve (112). The second gas-liquid separator (116) is located on the connection line between port c of the four-way reversing valve (102) and the gas supply compressor (101); The regenerator (113) includes two heat exchange circuits, one of which connects the first gas-liquid separator (117) and the third expansion valve (112), and the other heat exchange circuit connects the c port of the four-way reversing valve (102) to the input end of the second gas-liquid separator (116).

2. The electric vehicle heat pump air conditioning system according to claim 1, characterized in that, Also includes: The first valve (105) is connected in parallel with the first expansion valve (104); the second valve (108) is connected in parallel with the second expansion valve (109).

3. The electric vehicle heat pump air conditioning system according to claim 1, characterized in that, Also includes: The third valve (115) is located on the connection line between the injector (106) and the first expansion valve (104).

4. The electric vehicle heat pump air conditioning system according to claim 1, characterized in that, Also includes: The first indoor heat exchanger (103) is located on the connection line between the d port of the four-way reversing valve (102) and the first expansion valve (104); The second indoor heat exchanger (111) is located on the connection line between the third expansion valve (112) and the subcooler (107); The outdoor heat exchanger (110) is located on the connection line between the second expansion valve (109) and the four-way reversing valve (102) at port b.

5. The electric vehicle heat pump air conditioning system according to claim 4, characterized in that, The first indoor heat exchanger (103), the second indoor heat exchanger (111), and the outdoor heat exchanger (110) are microchannel heat exchangers.

6. The electric vehicle heat pump air conditioning system according to claim 1, characterized in that, The injector (106) is an adjustable injector with a built-in valve needle or an adjustable injector with multiple injectors.

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