Electric vehicle heat pump air conditioning system

Abstract

The embodiment of the present invention relates to the field of air conditioning technology, and discloses an electric vehicle heat pump air conditioning system, including: a first off-vehicle heat exchanger, a first air supply compressor, a first four-way valve, a first in-vehicle heat exchanger, an air supply evaporator, and a temperature control module; the air supply evaporator is connected to the first off-vehicle heat exchanger, the first off-vehicle heat exchanger is connected to the first air supply compressor through the first four-way valve, and the first air supply compressor is connected to the air supply evaporator; the air supply evaporator, the first in-vehicle heat exchanger, the first four-way valve, and the first air supply compressor are connected in sequence, and the temperature control module and the air supply evaporator form a cooling circuit. The electric vehicle heat pump air conditioning system provided by the embodiment of the present invention can realize the switching of cooling and heating modes; it can effectively recover the waste heat generated by components such as batteries and motors, and improve the system's cooling energy efficiency and heating performance at lower ambient temperatures.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning, and in particular to a heat pump air conditioning system for an electric vehicle. Background Art

[0002] Electric vehicles refer to vehicles that use electricity as a power source and are driven by electric motors. They are new energy vehicles and include pure electric vehicles, hybrid electric vehicles, and fuel cell electric vehicles. As electric vehicles have less impact on the environment than traditional vehicles, their development prospects are widely optimistic.

[0003] During the operation of electric vehicles, batteries, motors, etc. will generate a lot of heat, especially in the summer when the ambient temperature is high. If the heat is not dissipated in time, it will not only affect the working efficiency of the batteries and motors, but also shorten their service life. In the existing technology, this part of the heat is often wasted. If it can be effectively recycled, it will improve the overall energy efficiency of the thermal system, thereby increasing the mileage of electric vehicles. Summary of the invention

[0004] An embodiment of the present invention provides an electric vehicle heat pump air conditioning system, which is used to solve or partially solve the problem that the existing electric vehicle heat pump air conditioning system cannot reasonably use the heat emitted by the battery or the motor.

[0005] An embodiment of the present invention provides an electric vehicle heat pump air conditioning system, comprising: a first external heat exchanger, a first air supply compressor, a first four-way valve, and a first internal heat exchanger, and also comprising an air supply evaporator and a temperature control module;

[0006] The air supply evaporator is connected to the first external heat exchanger, the first external heat exchanger is connected to the first air supply compressor through the first four-way valve, and the first air supply compressor is connected to the air supply evaporator; the air supply evaporator, the first internal heat exchanger, the first four-way valve and the first air supply compressor are connected in sequence, and the temperature control module and the air supply evaporator form a cooling circuit.

[0007] On the basis of the above technical solution, the air supplement evaporator includes a flash tank and a coil located inside the flash tank, and the coil is installed at the bottom of the flash tank.

[0008] On the basis of the above technical solution, the temperature control module includes a cooling pipeline connected to the coil, and the interior of the cooling pipeline is filled with coolant.

[0009] Based on the above technical solution, a driving pump is installed on the cooling pipeline.

[0010] On the basis of the above technical solution, the air supplement evaporator is connected to the first in-vehicle heat exchanger through a first electronic expansion valve.

[0011] On the basis of the above technical solution, the air supplement evaporator is connected to the first off-vehicle heat exchanger through a second electronic expansion valve.

[0012] On the basis of the above technical solution, the electric vehicle heat pump air conditioning system further includes a second in-vehicle heat exchanger connected in parallel with the first in-vehicle heat exchanger.

[0013] On the basis of the above technical solution, the electric vehicle heat pump air conditioning system further includes a first gas-liquid separator, and the first four-way valve is connected to the first air supply compressor through the first gas-liquid separator.

[0014] On the basis of the above technical solution, the electric vehicle heat pump air conditioning system further includes a second off-board heat exchanger, a second four-way valve and a second air supply compressor;

[0015] The air supply evaporator is connected to the second external heat exchanger, the second external heat exchanger is connected to the second air supply compressor through the second four-way valve, the second air supply compressor is connected to the air supply evaporator; the first internal heat exchanger, the second four-way valve and the second air supply compressor are connected in sequence.

[0016] On the basis of the above technical solution, the electric vehicle heat pump air conditioning system further includes a second gas-liquid separator; the second four-way valve is connected to the second air supply compressor through the second gas-liquid separator.

[0017] An electric vehicle heat pump air conditioning system provided by an embodiment of the present invention utilizes the heat of a battery or a motor to convert the liquid refrigerant in the air supply evaporator into a medium-pressure gaseous refrigerant, and delivers the medium-pressure gaseous refrigerant to the air supply compressor. The electric vehicle heat pump air conditioning system provided by an embodiment of the present invention can realize the switching of cooling and heating modes; it can effectively recover the waste heat generated by components such as batteries and motors. Under summer conditions, in the process of waste heat recovery, it provides cooling capacity for batteries and motors, improves the heat dissipation effect of components such as batteries and motors, and especially under high temperature conditions in summer, the improvement of the temperature control module capacity is more significant. At the same time, the evaporation temperature of the air supply branch is increased, and the exhaust temperature of the air supply compressor is reduced, thereby improving the refrigeration energy efficiency of the system. Under winter conditions, due to the absorption of waste heat, the refrigerant temperature, pressure, quality and flow rate of the air supply branch are increased, thereby improving the heating performance of the system at lower ambient temperatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic structural diagram of a heat pump air conditioning system for an electric vehicle according to an embodiment of the present invention;

[0020] Figure 2 for Figure 1 Schematic diagram of cooling mode;

[0021] Figure 3 for Figure 1 Schematic diagram of heating mode;

[0022] Figure 4 A schematic structural diagram of another electric vehicle heat pump air conditioning system according to an embodiment of the present invention;

[0023] Figure 5 This is a pressure-enthalpy diagram of a heat pump air conditioning system for an electric vehicle according to an embodiment of the present invention.

[0024] Reference numerals:

[0025] 1. The first in-vehicle heat exchanger; 2. The temperature control module; 3. The first electronic expansion valve; 4. The second in-vehicle heat exchanger; 5. The air supply evaporator; 6. The first gas-liquid separator; 7. The first air supply compressor; 8. The first four-way valve; 9. The second electronic expansion valve; 10. The first out-vehicle heat exchanger; 11. The second out-vehicle heat exchanger; 12. The second four-way valve; 13. The second air supply compressor; 14. The second gas-liquid separator. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution 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 are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] Figure 1 FIG. 1 is a schematic diagram of the structure of a heat pump air conditioning system for an electric vehicle according to an embodiment of the present invention. Figure 1 As shown, it includes: a first external heat exchanger 10, a first air supply compressor 7, a first four-way valve 8, a first internal heat exchanger 1, an air supply evaporator 5 and a temperature control module 2;

[0029] The air supply evaporator 5 is connected to the first external heat exchanger 10, the first external heat exchanger 10 is connected to the first air supply compressor 7 through the first four-way valve 8, and the first air supply compressor 7 is connected to the air supply evaporator 5; the air supply evaporator 5, the first internal heat exchanger 1, the first four-way valve 8 and the first air supply compressor 7 are connected in sequence, and the temperature control module 2 and the air supply evaporator 5 form a cooling circuit.

[0030] It should be noted that the temperature control module 2 is used to dissipate heat from the power battery and / or motor in the electric vehicle.

[0031] The structure of the electric vehicle heat pump air conditioning system is described in detail below. The gaseous working medium outlet located at the top of the air-making evaporator 5 is connected to the air-making inlet of the first air-making compressor 7; an opening located at the bottom of the air-making evaporator 5 is connected to one end of the first external heat exchanger 10 through the second electronic expansion valve 9; the other end of the first external heat exchanger 10 is connected to the first interface of the first four-way valve 8, and the second interface of the first four-way valve 8 is connected to the exhaust outlet of the first air-making compressor 7; the fourth interface of the first four-way valve 8 is connected to the air intake inlet of the first air-making compressor 7 through the first gas-liquid separator 6; another opening located at the bottom of the air-making evaporator 5 is connected to one end of the first internal heat exchanger 1 through the first electronic expansion valve 3, and the other end of the first internal heat exchanger 1 is connected to the third interface of the first four-way valve 8.

[0032] The electric vehicle heat pump air conditioning system provided by the embodiment of the present invention uses the heat of the battery or the motor to convert the liquid refrigerant in the air supply evaporator into a medium-pressure gaseous refrigerant, and transports the medium-pressure gaseous refrigerant to the air supply compressor. The electric vehicle heat pump air conditioning system provided by the embodiment of the present invention can realize the switching of cooling and heating modes; it can effectively recover the waste heat generated by components such as batteries and motors. Under summer conditions, in the process of waste heat recovery, it provides cooling capacity for batteries and motors, improves the heat dissipation effect of components such as batteries and motors, especially under high temperature conditions in summer, the improvement of the temperature control module capacity is more significant, and at the same time increases the evaporation temperature of the air supply branch, reduces the exhaust temperature of the air supply compressor, thereby improving the refrigeration energy efficiency of the system. Under winter conditions, due to the absorption of waste heat, the refrigerant temperature, pressure, quality and flow rate of the air supply branch are increased, which improves the heating performance of the system at lower ambient temperatures.

[0033] On the basis of the above embodiment, the air supplement evaporator 5 includes a flash tank and a coil located inside the flash tank, and the coil is installed at the bottom of the flash tank.

[0034] It should be noted that the cooling liquid flowing through the coil exchanges heat with the refrigerant in the flash tank to release waste heat, the top of the flash tank is gaseous refrigerant, and the bottom of the flash tank is liquid refrigerant. The coil and the liquid refrigerant must remain in contact.

[0035] On the basis of the above embodiment, the temperature control module 2 includes a cooling pipeline connected to the coil, and the interior of the cooling pipeline is filled with coolant.

[0036] In an embodiment of the present invention, the cooling pipeline is connected to the coil to form a flow loop of the coolant, and the cooling pipeline is placed at the heating part or heating area of ​​the power battery and / or the motor to absorb heat.

[0037] It should be noted that, in order to increase the flow rate of the coolant, a driving pump is installed on the cooling pipeline.

[0038] On the basis of the above embodiment, the electric vehicle heat pump air conditioning system further includes a second in-vehicle heat exchanger 4 connected in parallel with the first in-vehicle heat exchanger 1 .

[0039] It should be noted that the first in-vehicle heat exchanger 1 and the second in-vehicle heat exchanger 4 are controlled by corresponding valves, and the first in-vehicle heat exchanger 1 and the second in-vehicle heat exchanger 4 can work simultaneously or independently.

[0040] Compared with the existing electric vehicle heat pump air-conditioning system in which the waste heat exchanger and the economizer are connected in parallel, the electric vehicle heat pump air-conditioning system in the embodiment of the present invention has a simpler structure, and the air supply branch is not affected by other branches, so it is easier to control; in addition, when the system switches between cooling and heating modes, the existing system needs to be adjusted through multiple valves, resulting in a complex system structure and large refrigerant flow resistance. In contrast, in the embodiment of the present invention, the switching of cooling and heating modes can be achieved through a four-way reversing valve, and the overall structure is simple and easy to control.

[0041] like Figure 2 As shown, in the cooling mode of the electric vehicle heat pump air-conditioning system, the first outdoor heat exchanger 10 is a condenser, the first indoor heat exchanger 1 and the second indoor heat exchanger 4 are evaporators, and the exhaust port of the first air-supplementing compressor 7 flows into the first outdoor heat exchanger 10 through the first four-way valve 8, flows through the second electronic expansion valve 9 after condensation, and enters the air-supplementing evaporator 5 after throttling. The refrigerant in the air-supplementing evaporator 5 exchanges heat with the coolant flowing through the coil, providing cooling capacity for components such as batteries and motors, improving the heat dissipation effect of components such as batteries and motors, especially under high temperature conditions in summer, the improvement of the temperature control module capacity is more significant, the refrigerant absorbs waste heat and evaporates, the medium-pressure gaseous refrigerant enters the first air-supplementing compressor 7 through the air-supplementing port, the liquid refrigerant flows through the first electronic expansion valve 3, and enters the evaporator after throttling, the refrigerant evaporates in the evaporator, absorbs heat in the vehicle interior, and the evaporated gaseous refrigerant flows through the first gas-liquid separator 6 and enters the first air-supplementing compressor 7 to complete the refrigeration cycle. Due to the heat transfer of components such as batteries and motors, the coolant temperature is high, which increases the evaporation temperature of the air supply branch, reduces the exhaust temperature of the first air supply compressor, and reduces the power consumption of the first air supply compressor, thereby improving the refrigeration energy efficiency of the system.

[0042] like Figure 3 As shown, in the heating mode of the electric vehicle heat pump air conditioning system, the first in-vehicle heat exchanger 1 and the second in-vehicle heat exchanger 4 are condensers, and the first out-vehicle heat exchanger 10 is an evaporator. The refrigerant in the air supply evaporator 5 exchanges heat with the coolant in the coil, absorbs the waste heat generated by the battery motor and other components, increases the temperature and pressure of the refrigerant in the air supply branch, and increases the mass flow of the refrigerant, thereby improving the heating performance of the heat pump system, especially under the condition of low ambient temperature, the improvement of the heating effect is more significant.

[0043] It should be noted that the first in-vehicle heat exchanger 1 and the second in-vehicle heat exchanger 4 are bidirectional heat exchangers. In the heating mode, the flow direction of the refrigerant in the in-vehicle heat exchanger is opposite to that in the cooling mode, avoiding the limitation of the in-vehicle heat exchanger being mutually restricted in the cooling and heating modes.

[0044] Based on the above embodiments, Figure 4As shown, the electric vehicle heat pump air conditioning system further includes a second external heat exchanger 11, a second four-way valve 12 and a second air supply compressor 13;

[0045] The air supply evaporator 5 is connected to the second external heat exchanger 11, the second external heat exchanger 11 is connected to the second air supply compressor 13 through the second four-way valve 12, and the second air supply compressor 13 is connected to the air supply evaporator 5; the first internal heat exchanger 1, the second four-way valve 12 and the second air supply compressor 13 are connected in sequence.

[0046] In the embodiment of the present invention, the gaseous working medium outlet located at the top of the air-supplement evaporator 5 is connected to the air-supplement inlet of the second air-supplement compressor 13; an opening located at the bottom of the air-supplement evaporator 5 is connected to one end of the second external heat exchanger 11; the other end of the second external heat exchanger 11 is connected to the first interface of the second four-way valve 12, and the second interface of the second four-way valve 12 is connected to the exhaust outlet of the second air-supplement compressor 13; the fourth interface of the second four-way valve 12 is connected to the intake inlet of the second air-supplement compressor 13 through the second gas-liquid separator 14; another opening located at the bottom of the air-supplement evaporator 5 is connected to one end of the first internal heat exchanger 1, and the other end of the first internal heat exchanger 1 is connected to the third interface of the second four-way valve 12.

[0047] like Figure 4 As shown, the heating mode and cooling mode of the electric vehicle heat pump air conditioning system of the embodiment of the present invention can be switched through a four-way reversing valve, which will not be repeated here. The first air supply compressor 7 and the second air supply compressor 13 can work at the same time, or only one can work. When the interior of the vehicle is cold or the heat load is large, the two air supply compressors work at the same time, and the first outdoor heat exchanger 10 and the second outdoor heat exchanger 11 both work, acting together on the entire system. Similarly, the two first indoor heat exchangers 1 and the second indoor heat exchangers 4 also work at the same time; when the interior of the vehicle is cold or the heat load is small, only one air supply compressor can be started, and at this time only one outdoor heat exchanger works, and the two indoor heat exchangers can work at the same time.

[0048] like Figure 5 As shown in Figure 2, when the electric vehicle heat pump air conditioning system with a flash evaporator has no waste heat recovery, Figure 5 As shown by the dotted line in the figure, the refrigerant coming out of the condenser enters the flash evaporator after a throttling operation, and the air supply state point H' is combined with the state point B to form C' and then further compressed to the state point D' and discharged; for the electric vehicle heat pump air conditioning system provided by the embodiment of the present invention, the refrigerant coming out of the condenser enters the air supply evaporator after a throttling operation, and the coolant absorbing the heat of the battery motor and other components flows through the coil in the air supply evaporator, and the liquid refrigerant in the air supply evaporator absorbs the waste heat and evaporates, as shown in FIG. Figure 5As shown by the solid line in the middle, compared with the system without waste heat recovery, the evaporation temperature of the air supply branch of the system of the present invention increases, and the temperature and pressure of the air supply state point H increase compared with H'. At the same time, due to the absorption of waste heat, the mass flow rate of the refrigerant in the air supply branch increases, and the enthalpy value of the state point C decreases compared with C', thereby reducing the exhaust temperature of the air supply compressor. Under the same working conditions, compared with the existing electric vehicle heat pump air conditioning system, the electric vehicle heat pump air conditioning system provided by the embodiment of the present invention has increased air supply temperature, air supply pressure, and the mass and flow rate of the refrigerant in the air supply branch, while reducing the exhaust temperature, thereby improving the energy efficiency of the system.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An electric vehicle heat pump air conditioning system, comprising: The first vehicle exterior heat exchanger, the first air supply compressor, the first four-way valve and the first vehicle interior heat exchanger are characterized in that they also include an air supply evaporator and a temperature control module; The air supply evaporator is connected to the first vehicle exterior heat exchanger, the first vehicle exterior heat exchanger is connected to the first air supply compressor through the first four-way valve, the first air supply compressor is connected to the air supply evaporator; the air supply evaporator, the first vehicle interior heat exchanger, the first four-way valve and the first air supply compressor are connected in sequence, and the temperature control module and the air supply evaporator form a cooling circuit; The air supplement evaporator comprises a flash tank and a coil located inside the flash tank, wherein the coil is installed at the bottom of the flash tank; The temperature control module includes a cooling pipeline connected to the coil, and the interior of the cooling pipeline is filled with coolant; wherein the cooling pipeline is placed at a heating part or heating area of ​​the power battery and / or the motor to absorb heat; The gaseous working medium outlet at the top of the air-supplementing evaporator is connected to the air-supplementing inlet of the first air-supplementing compressor; an opening at the bottom of the air-supplementing evaporator is connected to one end of the first off-vehicle heat exchanger through the second electronic expansion valve; the other end of the first off-vehicle heat exchanger is connected to the first interface of the first four-way valve, and the second interface of the first four-way valve is connected to the exhaust outlet of the first air-supplementing compressor; the fourth interface of the first four-way valve is connected to the air intake inlet of the first air-supplementing compressor through the first gas-liquid separator; another opening at the bottom of the air-supplementing evaporator is connected to one end of the first on-vehicle heat exchanger through the first electronic expansion valve, and the other end of the first on-vehicle heat exchanger is connected to the third interface of the first four-way valve; The electric vehicle heat pump air conditioning system further includes a second in-vehicle heat exchanger connected in parallel with the first in-vehicle heat exchanger.

2. The electric vehicle heat pump air conditioning system according to claim 1, characterized in that: A driving pump is installed on the cooling pipeline.

3. The electric vehicle heat pump air conditioning system according to claim 1, characterized in that: The air supplement evaporator is connected to the first in-vehicle heat exchanger through a first electronic expansion valve.

4. The electric vehicle heat pump air conditioning system according to claim 1, characterized in that: The air supplement evaporator is connected to the first off-vehicle heat exchanger through a second electronic expansion valve.

5. The electric vehicle heat pump air conditioning system according to any one of claims 1 to 4, characterized in that: The electric vehicle heat pump air conditioning system further includes a first gas-liquid separator, and the first four-way valve is connected to the first air supply compressor via the first gas-liquid separator.

6. The electric vehicle heat pump air conditioning system according to any one of claims 1 to 4, characterized in that: The electric vehicle heat pump air conditioning system also includes a second off-board heat exchanger, a second four-way valve and a second air supply compressor; The air supply evaporator is connected to the second external heat exchanger, the second external heat exchanger is connected to the second air supply compressor through the second four-way valve, the second air supply compressor is connected to the air supply evaporator; the first internal heat exchanger, the second four-way valve and the second air supply compressor are connected in sequence.

7. The electric vehicle heat pump air conditioning system according to claim 6, characterized in that: The electric vehicle heat pump air conditioning system further includes a second gas-liquid separator; the second four-way valve is connected to the second air supply compressor via the second gas-liquid separator.

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