A coupled thermal management system for electric vehicles and a working method thereof

Abstract

The technical solution of the present invention discloses a coupled thermal management system for an electric vehicle and a working method thereof, including an internal circulation system; an external circulation system coupled to the internal circulation system; and a single-system dual-circulation mode function is realized through system coupling between the internal circulation system and the external circulation system. The present invention adopts two mutually coupled thermal management systems to achieve the performance requirements of the passenger compartment air-conditioning system and the battery cooling system. At the same time, the two systems can provide performance complements to each other. It can not only meet the requirements of the passenger compartment and battery cooling at maximum load, but also improve the energy efficiency ratio of a single system during operation. At the same time, the economy of the system is also greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicles, and in particular to an electric vehicle coupled thermal management system and a working method thereof. Background Art

[0002] In electric vehicles, the thermal management system must not only meet the needs of passenger compartment air conditioning, but also the needs of battery cooling. The load of the thermal management system, especially the cooling load, spans a very large range.

[0003] After a vehicle has been exposed to the sun in the summer, people get into the car and hope that the air conditioning system can cool it down quickly.

[0004] When the battery is fast charging, it is also hoped that the thermal management system can provide a very large cooling capacity in a short period of time to meet the battery cooling needs during fast charging.

[0005] When the vehicle is running stably, especially in spring and autumn, the load on passenger compartment air conditioning and battery cooling is very small.

[0006] At present, electric vehicles use one thermal management system to manage both the passenger compartment and the battery. Or two independent systems are used to manage the passenger compartment and the battery respectively. If one system is used, it cannot meet the requirements of thermal management of the passenger compartment and the battery under high load; and if two independent thermal management systems are used, the performance requirements of each system are also very high, which is not economical. Summary of the invention

[0007] The technical problem solved by the present invention is that one system cannot meet the requirements of thermal management of the passenger compartment and the battery under high load; while two independent thermal management systems are used, the performance requirements of each system are also very high, which is not economical.

[0008] In order to solve the above technical problems, the technical solution of the present invention provides an electric vehicle coupled thermal management system, which includes:

[0009] Internal circulatory system;

[0010] An external circulation system coupled to the internal circulation system;

[0011] The single-system dual-circulation mode function is realized by system coupling between the internal circulation system and the external circulation system.

[0012] Optionally, the internal circulation system includes a first compressor, a first heat exchanger and a third heat exchanger respectively connected to the outlet and inlet of the first compressor, a fifth heat exchanger installed between the first heat exchanger and the third heat exchanger, a first throttling element installed between the fifth heat exchanger and the third heat exchanger, and a fan arranged next to the first heat exchanger.

[0013] Optionally, two ends of the third heat exchanger are respectively connected to a water pump and a battery pack, and the water pump is connected to the battery pack.

[0014] Optionally, the external circulation system includes a second compressor, a reversing valve and a gas-liquid separator respectively connected to the outlet and inlet of the second compressor, the reversing valve is connected to the gas-liquid separator, and the other two interfaces of the reversing valve are also connected in sequence to a second heat exchanger, a first three-way valve, a second throttling element, a fourth heat exchanger and a second three-way valve.

[0015] Optionally, the first three-way valve is further connected to the third heat exchanger, the third heat exchanger is connected to the second throttling element, the second three-way valve is further connected to the fifth heat exchanger, and the fifth heat exchanger is connected to the reversing valve.

[0016] In order to solve the above technical problems, the technical solution of the present invention further provides a working method of a coupled thermal management system for an electric vehicle, wherein the working method is as follows:

[0017] When in the normal load battery cooling cycle mode, the circulation route of the refrigerant is the first compressor-the first heat exchanger-the fifth heat exchanger-the first throttling element-the third heat exchanger-the first compressor, during which the fifth heat exchanger does not work;

[0018] When in the fast-charge battery cooling cycle mode, the refrigerant circulation route is the first compressor-first heat exchanger-fifth heat exchanger-first throttling element-third heat exchanger-first compressor, during which the fifth heat exchanger works and exchanges heat with the external circulation system;

[0019] When in the normal load passenger compartment refrigeration cycle mode, the refrigerant circulation route is the second compressor-reversing valve-second heat exchanger-first three-way valve-second throttling element-fourth heat exchanger-second three-way valve-reversing valve-gas-liquid separator-second compressor;

[0020] When in the enhanced passenger compartment refrigeration cycle mode, the refrigerant circulation route is the second compressor-reversing valve-second heat exchanger-first three-way valve-third heat exchanger-second throttling element-fourth heat exchanger-second three-way valve-reversing valve-gas-liquid separator-second compressor;

[0021] When in the normal load passenger compartment heating cycle mode, the refrigerant circulation route is the second compressor-reversing valve-second three-way valve-fourth heat exchanger-second throttling element-first three-way valve-second heat exchanger-reversing valve-gas-liquid separator-second compressor;

[0022] When in the waste heat recovery passenger compartment heating cycle mode, the refrigerant circulation route is the second compressor-reversing valve-second three-way valve-fourth heat exchanger-second throttling element-third heat exchanger-first three-way valve-second heat exchanger-reversing valve-gas-liquid separator-second compressor.

[0023] The beneficial effects of the technical solution of the present invention are:

[0024] The present invention adopts two mutually coupled thermal management systems to achieve the performance requirements of the passenger compartment air conditioning system and the battery cooling system. At the same time, the two systems can provide mutual performance complementation. It can not only meet the requirements of passenger compartment and battery cooling at maximum load, but also improve the energy efficiency ratio of a single system when running. At the same time, the economy of the system is also greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the structure of the electric vehicle coupled thermal management system in an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0027] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0028] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0029] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 an indirect connection 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.

[0030] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0031] See also Figure 1 As shown, an embodiment of an electric vehicle coupled thermal management system is shown, which includes an internal circulation system; an external circulation system coupled to the internal circulation system; and a single-system dual-circulation mode function is realized through system coupling between the internal circulation system and the external circulation system.

[0032] In this embodiment, the internal circulation system includes a first compressor 1, a first heat exchanger 11 and a third heat exchanger 31 respectively connected to the outlet and inlet of the first compressor 1, a fifth heat exchanger 32 installed between the first heat exchanger 11 and the third heat exchanger 31, a first throttling element 41 installed between the fifth heat exchanger 32 and the third heat exchanger 31, and a fan 5 arranged next to the first heat exchanger 11.

[0033] In this embodiment, two ends of the third heat exchanger 31 are respectively connected to the water pump 6 and the battery pack 7 , and the water pump 6 and the battery pack 7 are connected.

[0034] In this embodiment, the external circulation system includes a second compressor 2, a reversing valve 3 and a gas-liquid separator 4 respectively connected to the outlet and inlet of the second compressor 2, the reversing valve 3 is connected to the gas-liquid separator 4, and the other two interfaces of the reversing valve 3 are also connected in sequence with the second heat exchanger 21, the first three-way valve 51, the second throttling element 42, the fourth heat exchanger 22 and the second three-way valve 52.

[0035] In this embodiment, the first three-way valve 51 is also connected to the third heat exchanger 31 , the third heat exchanger 31 is connected to the second throttling element 42 , the second three-way valve 52 is also connected to the fifth heat exchanger 32 , and the fifth heat exchanger 32 is connected to the reversing valve 3 .

[0036] The following description is provided to further understand the characteristics and functions of the present invention.

[0037] This embodiment also provides a working method of an electric vehicle coupled thermal management system, wherein the working method is as follows:

[0038] 1. When in normal load battery cooling cycle mode, the refrigerant circulation route is first compressor 1 - first heat exchanger 11 - fifth heat exchanger 32 - first throttling element 41 - third heat exchanger 31 - first compressor 1, during which the fifth heat exchanger 32 does not work.

[0039] The high-temperature and high-pressure refrigerant at the outlet of the first compressor 1 exchanges heat (dissipates heat) with the outdoor air through the first heat exchanger 11 to reduce the temperature of the refrigerant. The refrigerant is throttled by the first throttling element 41 to become a low-temperature and low-pressure refrigerant, and exchanges heat (absorbs heat) with the battery coolant through the third heat exchanger 31 to cool the battery pack 7.

[0040] 2. When in the fast-charging battery cooling cycle mode, the refrigerant circulation route is the first compressor 1-the first heat exchanger 11-the fifth heat exchanger 32-the first throttling element 41-the third heat exchanger 31-the first compressor 1, during which the fifth heat exchanger 32 works and exchanges heat with the external circulation system.

[0041] The high-temperature and high-pressure refrigerant at the outlet of the first compressor 1 undergoes a first heat exchange (heat dissipation) with the outdoor air through the first heat exchanger 11 to reduce the temperature of the refrigerant, and then undergoes a second heat exchange (heat dissipation) with the low-temperature refrigerant of the external circulation system through the fifth heat exchanger 32 to further reduce the temperature of the refrigerant. The refrigerant is throttled by the first throttling element 41 to become a low-temperature and low-pressure refrigerant, and undergoes a heat exchange (heat absorption) with the battery coolant through the third heat exchanger 31 to cool the battery pack 7.

[0042] The temperature of the refrigerant at the outlet of the first compressor 1 is reduced twice, so that the refrigerant can fully dissipate heat, thereby improving the performance and energy efficiency of the system.

[0043] 3. When in the normal load passenger compartment refrigeration cycle mode, the refrigerant circulation route is the second compressor 2-reversing valve 3-second heat exchanger 21-first three-way valve 51-second throttling element 42-fourth heat exchanger 22-second three-way valve 52-reversing valve 3-gas-liquid separator 4-second compressor 2.

[0044] The high-temperature and high-pressure refrigerant at the outlet of the second compressor 2 exchanges heat (dissipates heat) with the ambient air through the second heat exchanger 21 to reduce the temperature; after being throttled by the second throttling element 42, it becomes a low-temperature and low-pressure refrigerant, exchanges heat (absorbs heat) with the air inside the vehicle through the fourth heat exchanger 22 to cool the passenger compartment.

[0045] 4. When in the enhanced passenger compartment refrigeration cycle mode, the refrigerant circulation route is second compressor 2-reversing valve 3-second heat exchanger 21-first three-way valve 51-third heat exchanger 31-second throttling element 42-fourth heat exchanger 22-second three-way valve 52-reversing valve 3-gas-liquid separator 4-second compressor 2.

[0046] The high-temperature and high-pressure refrigerant at the outlet of the second compressor 2 exchanges heat (dissipates heat) with the ambient air through the second heat exchanger 21 to reduce the temperature; continues to exchange heat (dissipate heat) with the low-temperature refrigerant of the battery cooling system through the third heat exchanger 31 to further reduce the temperature; after being throttled by the second throttling element 42, it becomes a low-temperature and low-pressure refrigerant, exchanges heat (absorbs heat) with the air inside the vehicle through the fourth heat exchanger 22 to cool the passenger compartment.

[0047] The temperature of the refrigerant at the outlet of the second compressor 2 is reduced twice, so that the refrigerant can fully dissipate heat, thereby improving the performance and energy efficiency of the system.

[0048] 5. When in the normal load passenger compartment heating cycle mode, the refrigerant circulation route is the second compressor 2-reversing valve 3-second three-way valve 52-fourth heat exchanger 22-second throttling element 42-first three-way valve 51-second heat exchanger 21-reversing valve 3-gas-liquid separator 4-second compressor 2.

[0049] The high-temperature and high-pressure refrigerant at the outlet of the second compressor 2 undergoes the first heat exchange (heat dissipation) with the indoor air in the vehicle through the fourth heat exchanger 22 to heat up the passenger compartment. It is then throttled by the second throttling element 42 to become a low-temperature and low-pressure refrigerant, undergoes heat exchange (heat absorption) with the ambient air through the second heat exchanger 21, and then returns to the compressor to continue compression.

[0050] 6. When in the waste heat recovery passenger compartment heating cycle mode, the refrigerant circulation route is the second compressor 2-reversing valve 3-second three-way valve 52-fourth heat exchanger 22-second throttling element 42-third heat exchanger 31-first three-way valve 51-second heat exchanger 21-reversing valve 3-gas-liquid separator 4-second compressor 2.

[0051] The high-temperature and high-pressure refrigerant at the outlet of the second compressor 2 undergoes the first heat exchange (heat dissipation) with the indoor air in the vehicle through the fourth heat exchanger 22 to heat up the passenger compartment. Then, it is throttled by the second throttling element 42 to become a low-temperature and low-pressure refrigerant, which undergoes heat exchange (heat absorption) with the coolant through the third heat exchanger 31, and then undergoes heat exchange (heat absorption) with the ambient air through the second heat exchanger 21 to increase the temperature for the second time. The performance and energy efficiency of the system are improved by absorbing heat twice. When the battery circuit coolant temperature rises to a sufficient temperature, the fan 5 stops working. The air conditioning system can meet the heating needs of the passenger compartment by absorbing heat from the coolant through the third heat exchanger 31 alone.

[0052] At the same time, at extremely low ambient temperatures, such as -50°C, the heating performance of the air-conditioning system is poor and the coolant temperature is not enough to provide heat for the air-conditioning system. At this time, an auxiliary heating device (such as PTC) can be connected in series or in parallel in the coolant circuit to provide heat for the air-conditioning system through the third heat exchanger 31, thereby improving the heating performance of the air-conditioning system.

[0053] The refrigerant in this embodiment can be R744, R290, R134a or other refrigerants.

[0054] In summary, the electric vehicle coupled thermal management system of this embodiment adopts two relatively independent thermal management systems, but does not require a single system to meet the needs of passenger compartment and battery thermal management at high loads respectively. Instead, the performance requirements are met through the coupling of the two systems, thereby improving the economy of the system. At the same time, through the coupling of the systems, the heat dissipation of high-temperature refrigerants is enhanced, thereby improving the refrigeration performance and energy efficiency of a single system. And through the coupling of the systems, the waste heat recovery of the battery coolant is achieved, thereby improving the heating performance of the passenger compartment thermal management system. Finally, the system solves the coupling of the dual systems well by adopting the third heat exchanger and the fifth heat exchanger without basically changing the original system.

[0055] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A coupled thermal management system for an electric vehicle, characterized in that: include: Internal circulatory system; An external circulation system coupled to the internal circulation system; A single-system dual-circulation mode function is realized by system coupling between the internal circulation system and the external circulation system; Wherein, the internal circulation system comprises a first compressor, a first heat exchanger and a third heat exchanger respectively connected to the outlet and the inlet of the first compressor, a fifth heat exchanger installed between the first heat exchanger and the third heat exchanger, a first throttling element installed between the fifth heat exchanger and the third heat exchanger, and a fan arranged beside the first heat exchanger; Wherein, the external circulation system comprises a second compressor, a reversing valve and a gas-liquid separator respectively connected to the outlet and inlet of the second compressor, the reversing valve is connected to the gas-liquid separator, and the other two interfaces of the reversing valve are also sequentially connected to the second heat exchanger, the first three-way valve, the second throttling element, the fourth heat exchanger and the second three-way valve; The first three-way valve is further connected to the third heat exchanger, the third heat exchanger is connected to the second throttling element, the second three-way valve is further connected to the fifth heat exchanger, and the fifth heat exchanger is connected to the reversing valve.

2. The electric vehicle coupled thermal management system according to claim 1, characterized in that: Both ends of the third heat exchanger are respectively connected to a water pump and a battery pack, and the water pump is connected to the battery pack.

3. A working method of a coupled thermal management system for an electric vehicle, characterized in that: The working method is as follows: When in the normal load battery cooling cycle mode, the circulation route of the refrigerant is the first compressor-the first heat exchanger-the fifth heat exchanger-the first throttling element-the third heat exchanger-the first compressor, during which the fifth heat exchanger does not work; When in the fast-charge battery cooling cycle mode, the refrigerant circulation route is the first compressor-first heat exchanger-fifth heat exchanger-first throttling element-third heat exchanger-first compressor, during which the fifth heat exchanger works and exchanges heat with the external circulation system; When in the normal load passenger compartment refrigeration cycle mode, the refrigerant circulation route is the second compressor-reversing valve-second heat exchanger-first three-way valve-second throttling element-fourth heat exchanger-second three-way valve-reversing valve-gas-liquid separator-second compressor; When in the enhanced passenger compartment refrigeration cycle mode, the refrigerant circulation route is the second compressor-reversing valve-second heat exchanger-first three-way valve-third heat exchanger-second throttling element-fourth heat exchanger-second three-way valve-reversing valve-gas-liquid separator-second compressor; When in the normal load passenger compartment heating cycle mode, the refrigerant circulation route is the second compressor-reversing valve-second three-way valve-fourth heat exchanger-second throttling element-first three-way valve-second heat exchanger-reversing valve-gas-liquid separator-second compressor; When in the waste heat recovery passenger compartment heating cycle mode, the refrigerant circulation route is the second compressor-reversing valve-second three-way valve-fourth heat exchanger-second throttling element-third heat exchanger-first three-way valve-second heat exchanger-reversing valve-gas-liquid separator-second compressor.

Images