Electric vehicle thermal management system suitable for R290 refrigerant

Abstract

An electric vehicle thermal management system suitable for R290 refrigerant comprises a refrigerant loop, a radiator, a motor, an in-vehicle heat exchanger assembly, a battery loop and an expansion kettle which are communicated through a cooling liquid pipeline, and a plurality of electronic water pumps are arranged on the cooling liquid pipeline. An R290 refrigerant flows in the refrigerant loop, and the R290 refrigerant only circulates in the refrigerant loop; cooling liquid flows in the cooling liquid pipeline, and the electronic water pump is used for providing flowing power for the cooling liquid. A plurality of three-way valves and a plurality of four-way valves are further arranged on the cooling liquid pipeline, the flowing direction of the cooling liquid is adjusted through combination and switching of the four-way valves so as to meet the requirements of different working conditions of refrigeration and heating, and the flow of the cooling liquid in each branch can be adjusted through the three-way valves; a heat pump system using R290 as a refrigerant is used as a core, and a series of combinations of peripheral water paths, valve bodies and heat exchangers are used in a matched mode, so that comprehensive management of heat in a vehicle is achieved.

Description

Technical Field

[0001] This invention relates to the field of thermal management technology for electric vehicles, specifically to a thermal management system for electric vehicles using R290 refrigerant. Background Technology

[0002] Currently, hydrofluorocarbon (HFC) refrigerants such as R134a are commonly used in automotive applications. However, they have a significant greenhouse effect (GWP=1430). According to the Kigali Amendment to the Montreal Protocol, which my country has signed, HFC refrigerants, including R134a, will be phased out. Furthermore, R134a has a boiling point of -26.3℃ at normal pressure, resulting in poor heating performance and efficiency at low temperatures, failing to meet the wide operating temperature range and environmental requirements of electric vehicle thermal management systems. R290 is a new alternative refrigerant with a low greenhouse effect (GWP=3) and is considered an environmentally friendly refrigerant. In addition, R290 offers advantages such as good low-temperature heating performance, large enthalpy difference per unit mass of phase change, low charge quantity, system pressure similar to R134a, and low procurement cost. While R290 has some flammability, the risks associated with flammability can be significantly reduced through proper design and layout. In view of the characteristics of R290 and the need for a high-efficiency, wide-temperature-range thermal management system, this application proposes a thermal management system for electric vehicles using R290 refrigerant. This system employs an indirect heat exchange scheme, using the refrigerant loop as the core to limit the refrigerant's flow range. Heat exchange between the refrigerant and coolant is achieved through a heat exchanger, with the coolant directly participating in the system's thermal management. This scheme not only reduces the risk of flammability but also aligns with the development trend of integrated and comprehensive heat management in electric vehicle thermal management systems. Summary of the Invention

[0003] The purpose of this invention is to provide a thermal management system for electric vehicles that is suitable for R290 refrigerant. This system can expand the lower limit of low-temperature use of electric vehicle thermal management systems and fully utilize the advantage of heat pump systems in providing heating in low-temperature environments, thereby significantly improving the system's heating efficiency and solving existing technical defects and unmet technical requirements.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a thermal management system for electric vehicles using R290 refrigerant, comprising a refrigerant circuit, a radiator, a motor, an in-vehicle heat exchanger assembly, a battery circuit, and an expansion tank, wherein the components are connected to each other via coolant pipes, and a plurality of electronic water pumps are provided on the coolant pipes; R290 (propane) refrigerant flows in the refrigerant circuit, and the R290 refrigerant only flows in the refrigerant circuit; Coolant flows through the coolant pipe, and the electronic water pump is used to provide the power for the flow of coolant. The coolant pipeline is also equipped with several three-way valves and several four-way valves. The flow direction of the coolant can be adjusted by combining and switching several four-way valves to meet the needs of different working conditions of cooling and heating. The flow rate of the coolant in each branch can be adjusted by several three-way valves. The radiator is installed outside the crew compartment to facilitate heat exchange between the coolant and the environment. The in-vehicle heat exchanger is installed in the passenger compartment and regulates the temperature inside the passenger compartment by blowing cold or hot air into it. The motor is used to drive the operation of various components within the system; The battery circuit is used to supply power to all electrical appliances in the system; The expansion tank is used to mitigate system pressure fluctuations caused by volume changes in the coolant due to temperature variations, maintain a certain level of coolant, and expel gas from the pipeline through the vent to ensure that the pipeline is filled with coolant.

[0005] In this application, it is necessary to further explain that the phrase "the above-mentioned components are connected by coolant pipes" means not only the components mentioned before this sentence, but also the connections between each circuit and between each circuit and components, all of which are connected by coolant pipes. In this application, the refrigerant flows only within the refrigerant circuit. In the external piping, an electric water pump drives the coolant flow, and the flow direction can be adjusted via a combination of four-way valves to meet the needs of different cooling and heating conditions. A three-way valve can adjust the coolant flow rate in each branch. An expansion tank mitigates system pressure fluctuations caused by coolant volume changes due to temperature variations, maintains a certain level of coolant in the system, and allows for gas discharge through the piping. The two in-vehicle heat exchangers are microchannel heat exchangers, through which coolant flows, and can be blown out with the help of a fan. The radiator is installed outside the passenger compartment, serving to exchange heat between the coolant and the environment.

[0006] Preferably, the refrigerant circuit includes a compressor, a water-cooled condenser, an electronic expansion valve, a chiller, and a gas-liquid separator. The above components are connected by refrigerant pipelines, and the R290 refrigerant flows in the refrigerant pipelines. The compressor, water-cooled condenser, electronic expansion valve, refrigeration unit, and gas-liquid separator are connected in sequence via refrigerant pipelines, and the gas-liquid separator is connected to the compressor via a refrigerant pipeline.

[0007] In this application, the refrigerant circuit operates as follows: the refrigerant is compressed by the compressor to form a high-temperature, high-pressure gas, which is then driven by the compressor to flow into the water-cooled condenser. There, it condenses and releases heat to the coolant. After flowing out of the water-cooled condenser, it flows through the expansion valve and is throttled to form a low-temperature, low-pressure liquid or gas-liquid mixture. This mixture then flows into the chiller, where the refrigerant evaporates and absorbs heat from the coolant to become a medium-temperature, low-pressure fluid. At this point, the fluid may still exist in a two-phase state of gas and liquid. Therefore, after flowing out of the chiller, it needs to flow into a gas-liquid separator to retain the liquid refrigerant, ensuring that the refrigerant re-enters the compressor in gaseous form to achieve the compression process. The refrigerant exists only within the refrigerant circuit and maintains this flow process continuously. Coolant and refrigerant flow simultaneously in the water-cooled condenser and the chiller. Cooled coolant flows out of the chiller and heated coolant flows out of the water-cooled condenser. The heat of the coolant is released and absorbed through the water-cooled condenser and the chiller, and the coolant directly participates in the thermal management of each component. The heating or cooling requests of each component are realized by switching the four-way valve.

[0008] Preferably, the compressor compresses R290 refrigerant into a high-temperature, high-pressure gas and drives the flow of R290 refrigerant. The water-cooled condenser condenses and dissipates the high-temperature, high-pressure R290 refrigerant gas, converting it into a low-temperature, low-pressure liquid or gas-liquid mixture. The electronic expansion valve throttles the output of the R290 refrigerant liquid or gas-liquid mixture. The refrigerator can convert the R290 refrigerant liquid or gas-liquid mixture into a medium-temperature, low-pressure fluid through heat exchange. The gas-liquid separator retains the liquid refrigerant, ensuring that the refrigerant re-enters the compressor in gaseous form to achieve the compression process.

[0009] Preferably, the refrigeration unit is connected to a first four-way valve via a coolant pipeline, the water-cooled condenser and the refrigeration unit are respectively connected to different interfaces of the first four-way valve, a first electronic water pump is provided between the water-cooled condenser and the first four-way valve, and a second electronic water pump is provided between the refrigeration unit and the first four-way valve. The end of the refrigeration unit away from the first four-way valve is also connected to a second four-way valve via a coolant pipe. The water-cooled condenser and the refrigeration unit are respectively connected to different interfaces of the second four-way valve.

[0010] Preferably, the other two ports on the first four-way valve are connected to the vehicle heat exchanger assembly and the radiator respectively via coolant pipes. A first three-way valve is provided between the first four-way valve and the vehicle heat exchanger assembly. The first four-way valve and the vehicle heat exchanger assembly are respectively connected to the two ports of the first three-way valve. A second three-way valve is provided between the first four-way valve and the radiator. The first four-way valve and the radiator are respectively connected to the two ports of the second three-way valve. The other two ports on the second four-way valve are connected to the motor and the vehicle heat exchanger assembly respectively via coolant pipes; The motor and radiator are connected via coolant pipes.

[0011] Preferably, the in-vehicle heat exchanger assembly includes a first in-vehicle heat exchanger and a second in-vehicle heat exchanger, which are connected sequentially via coolant pipes. The end of the first in-vehicle heat exchanger away from the second in-vehicle heat exchanger is connected to a first three-way valve, and the end of the second in-vehicle heat exchanger away from the first in-vehicle heat exchanger is connected to the interface of a second four-way valve. A fan is provided outside the first and second in-vehicle heat exchangers, and the air blown out by the fan must pass through the first and second in-vehicle heat exchangers before entering the passenger compartment.

[0012] In this application, as mentioned above, the first in-vehicle heat exchanger and the second in-vehicle heat exchanger are connected sequentially via coolant pipes. It should be noted that the two in-vehicle heat exchangers are also connected to each other via coolant channels.

[0013] Preferably, another port on the second three-way valve is connected to the coolant pipe between the motor and the radiator via a coolant pipe.

[0014] Preferably, one end of the expansion tank is connected to the end of the radiator away from the motor via a coolant pipe, and the other end is connected via a coolant pipe to the coolant pipe between the first three-way valve and the first in-vehicle heat exchanger, the coolant pipe between the second electronic water pump and the refrigeration unit, and the coolant pipe between the first electronic water pump and the water-cooled condenser.

[0015] Preferably, another port on the first three-way valve is connected to the battery circuit, and the end of the battery circuit away from the first three-way valve is connected to the coolant pipe between the second vehicle interior heat exchanger and the second four-way valve.

[0016] In this application, the "other interfaces" mentioned above refer to interfaces other than those connected to the same components mentioned above. In this application, these interfaces are mostly used for...

[0017] Preferably, both the first and second in-vehicle heat exchangers are microchannel heat exchangers.

[0018] In this application, the specific connection method is omitted for some structures. That is, the connection between some components is clearly stated to be through coolant pipes, while the connection between other components is not specifically described. Therefore, it is explained here that, except for the connection within the refrigerant circuit, which is through refrigerant pipes, the connections between other components and between components and the circuit are all through coolant pipes.

[0019] Compared with the prior art, the beneficial effects of the present invention are: 1. This application centers on a heat pump system using R290 as the refrigerant, combined with a series of peripheral water circuits, valves, and heat exchangers to achieve temperature and heat management of the electric vehicle's battery, motor, and passenger compartment. This ensures the battery and motor operate within suitable temperature ranges, guarantees thermal comfort in the passenger compartment, and achieves comprehensive heat management within the vehicle. Leveraging R290's superior low-temperature heating capability compared to the commonly used refrigerant R134a, the application expands the lower limit of low-temperature operation for electric vehicle thermal management systems. It eliminates the need for inefficient PTC (positive temperature coefficient) heaters, fully utilizing the heat pump system's ability to provide heating in low-temperature environments, thus significantly improving system heating efficiency. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram showing the flow direction of the refrigerant in this invention; Figure 3 This is a schematic diagram of the fluid flow direction in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the fluid flow direction in Embodiment 2 of the present invention; Figure 5 This is a schematic diagram of the fluid flow direction in Embodiment 3 of the present invention; Figure 6 This is a schematic diagram of the fluid flow direction in Embodiment 4 of the present invention; Figure 7 This is a schematic diagram of the fluid flow direction in Embodiment 5 of the present invention; Figure 8 This is a schematic diagram of the fluid flow direction in Embodiment 6 of the present invention; Figure 9 This is a schematic diagram of the fluid flow direction in Embodiment 7 of the present invention; Figure 10 This is a schematic diagram of the fluid flow direction in Embodiment 8 of the present invention; Figure 11 This is a schematic diagram of the fluid flow direction in Embodiment 9 of the present invention; Detailed Implementation

[0021] The following will refer to the appendices in the embodiments of the present invention. Figure 1-11 The technical solutions in the embodiments of the present invention are clearly and completely described herein. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature.

[0023] Please see Figure 1-11 Embodiments of the present invention: Example

[0024] like Figure 1 As shown: In all embodiments of this application, it should be explained that, for ease of expression, the first, second, third, and fourth, etc. in this application are all represented by numbers in the figures. For example, the first electronic water pump is represented by electronic water pump 1 in the figure, and other names are represented by the same method. Adding "-number" after the corresponding name indicates that the component corresponding to this name has a different interface.

[0025] Furthermore, based on the above description, the four-way valve (first four-way valve and second four-way valve) in this application has two operating modes: Mode 1 is a connection between ports 1 and 2, and between ports 3 and 4; Mode 2 is a connection between ports 1 and 4, and between ports 2 and 3. By switching between modes, the connection between the water circuit and the refrigerant circuit heat exchanger can be switched. This ensures that the refrigerant circuit remains as described above. Figure 2 When operating in the indicated direction, the water circuit connection can be switched via two four-way valves to meet the different heat requirements of each thermal management component. A three-way valve can achieve a proportional distribution of flow between the two pipes. The three-way valve has inlet 1 and can be set to a certain ratio to distribute the flow between outlet 2 and outlet 3.

[0026] In addition, in this application, such as Figure 2As shown, the refrigerant circuit operates as follows: after being compressed by the compressor, the refrigerant forms a high-temperature, high-pressure gas, which is then driven by the compressor to flow into the water-cooled condenser-1 port. It condenses and releases heat to the coolant. After flowing out from the water-cooled condenser-2 port, it flows through the expansion valve and becomes a low-temperature, low-pressure liquid or gas-liquid mixture. It then flows into the chiller-2 port, where the refrigerant evaporates and absorbs heat from the coolant to become a medium-temperature, low-pressure fluid. At this point, the fluid may still exist in a two-phase state of gas and liquid. Therefore, after flowing out from the chiller-1 port, it needs to flow into the gas-liquid separator to retain the liquid refrigerant, ensuring that the refrigerant re-enters the compressor in gaseous form to achieve the compression process. The refrigerant exists only within the refrigerant circuit and maintains this flow process at all times. Coolant and refrigerant flow simultaneously in the water-cooled condenser and the chiller. Cold water flows out of the chiller and hot water flows out of the water-cooled condenser. The heat of the coolant is released and absorbed through the water-cooled condenser and the chiller, and the coolant directly participates in the thermal management of each component. The heating or cooling requests of each component are realized by switching the four-way valve.

[0027] The above description pertains to the overall content of this application. For ease of understanding, the description is based on the accompanying drawings and is not intended to be included in the invention description. However, it is not limited to the content of Embodiment 1, so it is explained here.

[0028] In all embodiments of this application, water is used as the coolant, and the water path in the embodiments refers to the flow path of the coolant.

[0029] The specific content of Embodiment 1 of this application is as follows: like Figure 3 As shown: When the system is in a state of occupant compartment cooling, battery not required, motor cooling or not required, the system water flow direction is as follows: Figure 3 As shown.

[0030] The fluid flow direction in the refrigerant circuit is always as follows Figure 2 As shown.

[0031] Under this operating condition, both four-way valve 1 and four-way valve 2 are in mode two. The water flow is divided into two parts: the chiller circuit and the water-cooled condenser circuit.

[0032] The flow process in the chiller circuit is as follows: Chiller -3 port → Electric water pump 2 → Four-way valve 1-3 port → Four-way valve 1-2 port → Three-way valve 1-1 port. The three-way valve controls the water flow ratio, directing all water to three-way valve 1-3 port. The subsequent flow process is: Three-way valve 1-3 port → Interior heat exchanger 1 → Interior heat exchanger 2 → Four-way valve 2-2 → Four-way valve 2-3 → Chiller -4 port. In this circuit, the low-temperature coolant flowing from the chiller flows into the two interior heat exchangers, providing cooling for the passenger compartment. The coolant then flows back to the chiller for recooling.

[0033] The flow process in the water-cooled condenser circuit is as follows: Water-cooled condenser port-3 → Electronic water pump 1 → Four-way valve port 1-1 → Four-way valve port 1-4 → Three-way valve port 2-1. The three-way valve controls the proportion of water flow, directing all water to three-way valve port 2-2. The subsequent flow process is: Three-way valve port 2-2 → Radiator → Motor → Four-way valve port 2-4 → Four-way valve port 2-1 → Water-cooled condenser port-4. In this circuit, the coolant absorbs the heat released by the refrigerant in the water-cooled condenser and releases the heat to the environment as it flows through the radiator. At this time, the coolant can be used to cool the motor or to achieve motor temperature equalization within a suitable temperature range. After flowing through the motor, it flows back to the water-cooled condenser via four-way valve 2 to absorb the heat from the refrigerant again.

[0034] In this operating condition, the chiller in the refrigerant circuit absorbs the heat from the coolant flowing out of the passenger compartment and releases it into the coolant in the water-cooled condenser circuit at the water-cooled condenser, and finally releases it into the environment through the radiator. Example

[0035] like Figure 4 As shown: When the system is in a state of no demand in the occupant compartment, battery cooling, motor heat dissipation, or no demand, the system water flow direction is as follows: Figure 4 As shown. The fluid flow direction in the refrigerant circuit is always as follows. Figure 2 As shown. Under this operating condition, both four-way valve 1 and four-way valve 2 are in mode two. The water flow is divided into two parts: the chiller circuit and the water-cooled condenser circuit.

[0036] The flow process in the chiller circuit is as follows: Chiller -3 port → Electric water pump 2 → Four-way valve 1-3 port → Four-way valve 1-2 port → Three-way valve 1-1 port. The three-way valve controls the proportion of water flow, directing all water to three-way valve 1-2 port. The subsequent flow process is: Three-way valve 1-2 port → Battery → Four-way valve 2-2 → Four-way valve 2-3 → Chiller -4 port. In this circuit, the low-temperature coolant flowing from the chiller flows into the battery, providing cooling, and then the coolant flows back to the chiller for recooling.

[0037] The flow process in the water-cooled condenser circuit is as follows: Water-cooled condenser port-3 → Electronic water pump 1 → Four-way valve port 1-1 → Four-way valve port 1-4 → Three-way valve port 2-1. The three-way valve controls the proportion of water flow, directing all water to three-way valve port 2-2. The subsequent flow process is: Three-way valve port 2-2 → Radiator → Motor → Four-way valve port 2-4 → Four-way valve port 2-1 → Water-cooled condenser port-4. In this circuit, the coolant absorbs the heat released by the refrigerant in the water-cooled condenser and releases the heat to the environment as it flows through the radiator. At this time, the coolant can be used to cool the motor or to achieve motor temperature equalization within a suitable temperature range. After flowing through the motor, it flows back to the water-cooled condenser via four-way valve 2 to absorb the heat from the refrigerant again.

[0038] In this operating condition, the chiller in the refrigerant circuit absorbs the heat from the coolant flowing out of the battery and releases it into the coolant in the water-cooled condenser circuit at the water-cooled condenser, and finally releases it into the environment through the radiator. Example

[0039] like Figure 5 As shown: The system water flow direction under conditions of crew compartment cooling, battery cooling, motor heat dissipation, or no demand is as follows. Figure 5 As shown. The fluid flow direction in the refrigerant circuit is always as follows. Figure 2 As shown. Under this operating condition, both four-way valve 1 and four-way valve 2 are in mode two. The water flow is divided into two parts: the chiller circuit and the water-cooled condenser circuit.

[0040] The flow process in the chiller circuit is as follows: Chiller - Port 3 → Electric Water Pump 2 → Four-way Valve Ports 1-3 → Four-way Valve Ports 1-2 → Three-way Valve Port 1-1. The three-way valve controls the water flow to three-way valve ports 2-2 and 2-3 in a certain proportion. The subsequent flow process is as follows: one path flows to the battery: Three-way Valve Port 2-3 → Battery; the other path flows to the vehicle interior heat exchanger: Three-way Valve Port 2-3 → Vehicle Interior Heat Exchanger 1 → Vehicle Interior Heat Exchanger 2. The two water flows merge and flow to four-way valve port 2-2. The flow process after merging is: Four-way Valve Port 2-2 → Four-way Valve Port 2-3 → Chiller - Port 4. In this circuit, the cryogenic coolant flowing from the chiller is distributed in a certain proportion to the battery and two in-vehicle heat exchangers at the three-way valve 1, providing battery cooling and passenger compartment cooling functions. Subsequently, the two streams of water merge and flow into the chiller for recooling via the four-way valve 2.

[0041] The flow process in the water-cooled condenser circuit is as follows: Water-cooled condenser -3 port → Electronic water pump 1 → Four-way valve 1-1 port → Four-way valve 1-4 port → Three-way valve 2-1 port → Three-way valve 2-2 port. The three-way valve controls the proportion of water flow, directing all water to three-way valve 2-2 port. The subsequent flow process is: Three-way valve 2-2 port → Radiator → Motor → Four-way valve 2-4 port → Four-way valve 2-1 port → Water-cooled condenser -4 port. In this circuit, the coolant absorbs the heat released by the refrigerant in the water-cooled condenser and releases the heat to the environment as it flows through the radiator. At this time, the coolant can be used to cool the motor or to achieve motor temperature equalization within a suitable temperature range. After flowing through the motor, it flows back to the water-cooled condenser via four-way valve 2 to absorb the heat from the refrigerant again.

[0042] In this operating condition, the chiller in the refrigerant circuit absorbs heat from the battery and the coolant flowing out of the passenger compartment, and releases it into the coolant in the water-cooled condenser circuit at the water-cooled condenser, and finally releases it into the environment through the radiator. Example

[0043] like Figure 6 As shown: The system water flow direction under the following conditions: crew compartment cooling, battery cooling, motor heat dissipation, or no demand (motor + ambient heat source) is as follows. Figure 6 As shown. The fluid flow direction in the refrigerant circuit is always as follows. Figure 2 As shown. Under this operating condition, both four-way valve 1 and four-way valve 2 are in mode one. The water flow is divided into two parts: the chiller circuit and the water-cooled condenser circuit.

[0044] The flow process in the chiller circuit is as follows: Chiller -3 port → Electric water pump 2 → Four-way valve 1-3 port → Four-way valve 1-4 port → Three-way valve 2-1 port. The three-way valve controls the proportion of water flow, directing all water to three-way valve 2-2 port. The subsequent flow process is: Three-way valve 2-2 port → Radiator → Motor → Four-way valve 2-4 port → Four-way valve 2-3 port → Chiller -4 port. In this circuit, the low-temperature coolant flowing from the chiller flows into the radiator. At this point, the coolant temperature is lower than the ambient temperature. The coolant absorbs heat from the environment in the radiator and then flows into the motor for cooling or to achieve motor temperature equalization within a suitable temperature range. It can also absorb the waste heat released by the motor. After flowing through the motor, it flows back to the chiller via four-way valve 2, releasing the heat absorbed from the environment and the motor into the refrigerant circuit.

[0045] The flow process in the water-cooled condenser circuit is as follows: Water-cooled condenser port-3 → Electric water pump 1 → Four-way valve port 1-1 → Four-way valve port 1-2 → Three-way valve port 1-1. The three-way valve controls the proportion of water flow, directing all water to three-way valve port 1-3. The subsequent flow process is: Three-way valve port 1-3 → In-vehicle heat exchanger 1 → In-vehicle heat exchanger 2 → Four-way valve 2-2 → Four-way valve 2-1 → Water-cooled condenser port-4. In this circuit, the coolant absorbs the heat released by the refrigerant in the water-cooled condenser. This heat includes heat absorbed from the environment, waste heat from the motor, and heat generated by the compressor's power consumption. The coolant then flows to the two in-vehicle heat exchangers to release heat to meet the heating needs of the passenger compartment. Finally, it flows back to the water-cooled condenser through four-way valve 2 to absorb heat again.

[0046] Under this operating condition, the cryogenic coolant flowing from the chiller absorbs heat from the environment and the motor. This heat, combined with the compressor's power consumption, is released into the coolant in the water-cooled condenser circuit. This coolant then flows into the vehicle's heat exchanger to meet the heating needs of the passenger compartment. This operating condition can absorb heat from the environment and utilize the waste heat released by the motor, achieving a coefficient of performance (COP) > 1, meeting the requirements for efficient system operation. Example

[0047] like Figure 7 As shown: The system water flow direction under the following conditions: crew compartment cooling, battery cooling, motor heat dissipation, or no demand (motor heat source) is as follows. Figure 7 As shown. The fluid flow direction in the refrigerant circuit is always as follows. Figure 2 As shown. Under this operating condition, both four-way valve 1 and four-way valve 2 are in mode one. The water flow is divided into two parts: the chiller circuit and the water-cooled condenser circuit.

[0048] The flow process in the chiller circuit is as follows: Chiller -3 port → Electric water pump 2 → Four-way valve 1-3 port → Four-way valve 1-4 port → Three-way valve 2-1 port. The three-way valve controls the proportion of water flow, directing all water to three-way valve 2-3 port to bypass the radiator. The subsequent flow process is: Three-way valve 2-3 port → Motor → Four-way valve 2-4 port → Four-way valve 2-3 port → Chiller -4 port. In this circuit, the low-temperature coolant flowing from the chiller flows into the motor for cooling or to achieve motor temperature equalization within a suitable temperature range. At this time, it can absorb the excess heat released by the motor. After flowing through the motor, it flows back to the chiller via four-way valve 2, releasing the heat absorbed from the motor into the refrigerant circuit.

[0049] The flow process in the water-cooled condenser circuit is as follows: Water-cooled condenser port-3 → Electronic water pump 1 → Four-way valve port 1-1 → Four-way valve port 1-2 → Three-way valve port 1-1. The three-way valve controls the proportion of water flow, directing all water to three-way valve port 1-3. The subsequent flow process is: Three-way valve port 1-3 → Interior heat exchanger 1 → Interior heat exchanger 2 → Four-way valve 2-2 → Four-way valve 2-1 → Water-cooled condenser port-4. In this circuit, the coolant absorbs the heat released by the refrigerant in the water-cooled condenser. This heat includes both the heat absorbed from the environment and the heat consumed by the compressor. The coolant then flows to the two interior heat exchangers to release heat to meet the heating needs of the passenger compartment, and finally flows back to the water-cooled condenser through four-way valve 2 to absorb heat again.

[0050] This operating condition is suitable for situations where the waste heat from the motor alone can meet the heating needs of the passenger compartment. In this condition, the low-temperature coolant flowing from the chiller absorbs heat from the motor, and this heat, combined with the compressor's power consumption, is released into the coolant in the water-cooled condenser circuit. This coolant then flows into the vehicle's heat exchanger to meet the passenger compartment's heating requirements. This operating condition fully utilizes the waste heat released by the motor, reducing dependence on ambient low-temperature heat sources and achieving a coefficient of performance (COP) > 1, meeting the requirements for efficient system operation. Example

[0051] like Figure 8 As shown: The system water flow direction under the following conditions: no demand in the crew compartment, battery heating, motor cooling, or no demand (motor + ambient heat source) is as follows. Figure 8 As shown. The fluid flow direction in the refrigerant circuit is always as follows. Figure 2 As shown. Under this operating condition, both four-way valve 1 and four-way valve 2 are in mode one. The water flow is divided into two parts: the chiller circuit and the water-cooled condenser circuit.

[0052] The flow process in the chiller circuit is as follows: Chiller -3 port → Electric water pump 2 → Four-way valve 1-3 port → Four-way valve 1-4 port → Three-way valve 2-1 port. The three-way valve controls the proportion of water flow, directing all water to three-way valve 2-2 port. The subsequent flow process is: Three-way valve 2-2 port → Radiator → Motor → Four-way valve 2-4 port → Four-way valve 2-3 port → Chiller -4 port. In this circuit, the low-temperature coolant flowing from the chiller flows into the radiator. At this point, the coolant temperature is lower than the ambient temperature. The coolant absorbs heat from the environment in the radiator and then flows into the motor for cooling or to achieve motor temperature equalization within a suitable temperature range. It can also absorb the waste heat released by the motor. After flowing through the motor, it flows back to the chiller via four-way valve 2, releasing the heat absorbed from the environment and the motor into the refrigerant circuit.

[0053] The flow process in the water-cooled condenser circuit is as follows: Water-cooled condenser port-3 → Electric water pump 1 → Four-way valve port 1-1 → Four-way valve port 1-2 → Three-way valve port 1-1. The three-way valve controls the proportion of water flow, directing all water to three-way valve port 1-2. The subsequent flow process is: Three-way valve port 1-2 → Battery → Four-way valve 2-2 → Four-way valve 2-1 → Water-cooled condenser port-4. In this circuit, the coolant absorbs the heat released by the refrigerant in the water-cooled condenser. This heat includes heat absorbed from the environment, waste heat from the motor, and heat generated by the compressor's power consumption. The coolant then flows to the battery, releasing heat to meet the battery's heating needs, and finally flows back to the water-cooled condenser through four-way valve 2 to absorb heat again.

[0054] Under this operating condition, the cryogenic coolant flowing from the chiller absorbs heat from the environment and the motor. This heat, combined with the compressor's power consumption, is released into the coolant in the water-cooled condenser circuit. This coolant then flows into the battery to meet its heating requirements. This operating condition can absorb heat from the environment and utilize the waste heat released by the motor, achieving a coefficient of performance (COP) > 1, thus meeting the requirements for efficient system operation. Example

[0055] like Figure 9 As shown: The system water flow direction under the following conditions: no demand in the crew compartment, battery heating, motor cooling, or no demand (motor heat source) is as follows. Figure 9 As shown. The fluid flow direction in the refrigerant circuit is always as follows. Figure 2 As shown. Under this operating condition, both four-way valve 1 and four-way valve 2 are in mode one. The water flow is divided into two parts: the chiller circuit and the water-cooled condenser circuit.

[0056] The flow process in the chiller circuit is as follows: Chiller -3 port → Electric water pump 2 → Four-way valve 1-3 port → Four-way valve 1-4 port → Three-way valve 2-1 port. The three-way valve controls the proportion of water flow, directing all water to three-way valve 2-3 port to bypass the radiator. The subsequent flow process is: Three-way valve 2-3 port → Motor → Four-way valve 2-4 port → Four-way valve 2-3 port → Chiller -4 port. In this circuit, the low-temperature coolant flowing from the chiller flows into the motor for cooling or to achieve motor temperature equalization within a suitable temperature range. At this time, it can absorb the excess heat released by the motor. After flowing through the motor, it flows back to the chiller via four-way valve 2, releasing the heat absorbed from the motor into the refrigerant circuit.

[0057] The flow process in the water-cooled condenser circuit is as follows: Water-cooled condenser port-3 → Electric water pump 1 → Four-way valve port 1-1 → Four-way valve port 1-2 → Three-way valve port 1-1. The three-way valve controls the proportion of water flow, directing all water to three-way valve port 1-2. The subsequent flow process is: Three-way valve port 1-2 → Battery → Four-way valve 2-2 → Four-way valve 2-1 → Water-cooled condenser port-4. In this circuit, the coolant absorbs the heat released by the refrigerant in the water-cooled condenser. This heat includes heat absorbed from the environment, waste heat from the motor, and heat generated by the compressor's power consumption. The coolant then flows to the battery, releasing heat to meet the battery's heating needs, and finally flows back to the water-cooled condenser through four-way valve 2 to absorb heat again.

[0058] This operating mode is suitable for situations where the battery heating needs can be met solely by the waste heat from the motor. In this mode, the cryogenic coolant flowing from the chiller absorbs heat from the motor, and this heat, combined with the compressor's power consumption, is released into the coolant in the water-cooled condenser circuit. This coolant then flows back into the battery to meet its heating requirements. This mode fully utilizes the waste heat released by the motor, reducing dependence on ambient low-temperature heat sources and achieving a coefficient of performance (COP) > 1, meeting the requirements for high-efficiency system operation. Example

[0059] like Figure 10 As shown: The system water flow direction under the following conditions: crew compartment heating, battery heating, motor cooling, or no demand (motor heat source) is as follows. Figure 10 As shown. The fluid flow direction in the refrigerant circuit is always as follows. Figure 2 As shown. Under this operating condition, both four-way valve 1 and four-way valve 2 are in mode one. The water flow is divided into two parts: the chiller circuit and the water-cooled condenser circuit.

[0060] The flow process in the chiller circuit is as follows: Chiller -3 port → Electric water pump 2 → Four-way valve 1-3 port → Four-way valve 1-4 port → Three-way valve 2-1 port. The three-way valve controls the proportion of water flow, directing all water to three-way valve 2-2 port. The subsequent flow process is: Three-way valve 2-2 port → Radiator → Motor → Four-way valve 2-4 port → Four-way valve 2-3 port → Chiller -4 port. In this circuit, the low-temperature coolant flowing from the chiller flows into the radiator. At this point, the coolant temperature is lower than the ambient temperature. The coolant absorbs heat from the environment in the radiator and then flows into the motor for cooling or to achieve motor temperature equalization within a suitable temperature range. It can also absorb the waste heat released by the motor. After flowing through the motor, it flows back to the chiller via four-way valve 2, releasing the heat absorbed from the environment and the motor into the refrigerant circuit.

[0061] The flow process in the water-cooled condenser circuit is as follows: Water-cooled condenser port-3 → Electronic water pump 1 → Four-way valve port 1-1 → Four-way valve port 1-2 → Three-way valve port 1-1. The three-way valve controls the water flow to three-way valve ports 2-2 and 2-3 respectively in a certain proportion. The subsequent flow process is as follows: one path flows to the battery (three-way valve port 2-3 → battery), and the other path flows to the vehicle interior heat exchanger (three-way valve port 2-3 → vehicle interior heat exchanger 1 → vehicle interior heat exchanger 2). The two water flows merge and flow to four-way valve port 2-2. The flow process after merging is: Four-way valve port 2-2 → Four-way valve port 2-1 → Water-cooled condenser port-4. In this circuit, the coolant absorbs the heat released by the refrigerant in the water-cooled condenser. This heat includes the heat absorbed by the environment, the waste heat of the motor, and the heat generated by the compressor power consumption. The coolant then flows to the battery and two in-vehicle heat exchangers to release the heat to meet the heating needs of the passenger compartment and the battery. Finally, it flows back to the water-cooled condenser through the four-way valve 2 to absorb heat again.

[0062] Under this operating condition, the cryogenic coolant flowing from the chiller absorbs heat from the environment and the motor. This heat, combined with the compressor's power consumption, is released at the water-cooled condenser circuit into the coolant. This coolant then flows into the vehicle's heat exchanger and battery to meet the heating needs of the passenger compartment and the battery. This operating condition can absorb heat from the environment and utilize the waste heat released by the motor, achieving a coefficient of performance (COP) > 1, meeting the requirements for efficient system operation. Example

[0063] like Figure 11 As shown: The system water flow direction under the following conditions: crew compartment heating, battery heating, motor cooling, or no demand (motor heat source) is as follows. Figure 11 As shown. The fluid flow direction in the refrigerant circuit is always as follows. Figure 2 As shown. Under this operating condition, both four-way valve 1 and four-way valve 2 are in mode one. The water flow is divided into two parts: the chiller circuit and the water-cooled condenser circuit.

[0064] The flow process in the chiller circuit is as follows: Chiller -3 port → Electric water pump 2 → Four-way valve 1-3 port → Four-way valve 1-4 port → Three-way valve 2-1 port. The three-way valve controls the proportion of water flow, directing all water to three-way valve 2-3 port to bypass the radiator. The subsequent flow process is: Three-way valve 2-3 port → Motor → Four-way valve 2-4 port → Four-way valve 2-3 port → Chiller -4 port. In this circuit, the low-temperature coolant flowing from the chiller flows into the motor for cooling or to achieve motor temperature equalization within a suitable temperature range. At this time, it can absorb the excess heat released by the motor. After flowing through the motor, it flows back to the chiller via four-way valve 2, releasing the heat absorbed from the motor into the refrigerant circuit.

[0065] The flow process in the water-cooled condenser circuit is as follows: Water-cooled condenser port-3 → Electronic water pump 1 → Four-way valve port 1-1 → Four-way valve port 1-2 → Three-way valve port 1-1. The three-way valve controls the water flow to three-way valve ports 2-2 and 2-3 respectively in a certain proportion. The subsequent flow process is as follows: one path flows to the battery (three-way valve port 2-3 → battery), and the other path flows to the vehicle interior heat exchanger (three-way valve port 2-3 → vehicle interior heat exchanger 1 → vehicle interior heat exchanger 2). The two water flows merge and flow to four-way valve port 2-2. The flow process after merging is: Four-way valve port 2-2 → Four-way valve port 2-1 → Water-cooled condenser port-4. In this circuit, the coolant absorbs the heat released by the refrigerant in the water-cooled condenser. This heat includes the waste heat of the motor and the heat generated by the compressor. The coolant then flows to the battery and two in-vehicle heat exchangers to release the heat to meet the heating needs of the passenger compartment and the battery. Finally, it flows back to the water-cooled condenser through the four-way valve 2 to absorb heat again.

[0066] This operating condition is suitable for situations where the waste heat from the motor alone can meet the battery heating requirements. In this condition, the low-temperature coolant flowing from the chiller absorbs heat from the motor, and this heat, combined with the compressor's power consumption, is released at the water-cooled condenser circuit into the coolant. This coolant then flows into the vehicle's heat exchanger and battery to meet the heating needs of the passenger compartment and the battery. This operating condition fully utilizes the waste heat released by the motor, reduces dependence on ambient low-temperature heat sources, achieves a coefficient of performance (COP) > 1, and meets the requirements for efficient system operation.

[0067] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0068] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A thermal management system for electric vehicles using R290 refrigerant, characterized in that, It includes a refrigerant circuit, a radiator, a motor, an in-vehicle heat exchanger assembly, a battery circuit, and an expansion tank. The components are connected to each other via coolant pipes, and several electronic water pumps are installed on the coolant pipes. R290 refrigerant flows in the refrigerant circuit, and the R290 refrigerant only flows in the refrigerant circuit; Coolant flows through the coolant pipe, and the electronic water pump is used to provide the power for the flow of coolant. The coolant pipeline is also equipped with several three-way valves and several four-way valves. The flow direction of the coolant can be adjusted by combining and switching several four-way valves to meet the needs of different working conditions of cooling and heating. The flow rate of the coolant in each branch can be adjusted by several three-way valves. The radiator is installed outside the crew compartment to facilitate heat exchange between the coolant and the environment. The in-vehicle heat exchanger is installed in the passenger compartment and regulates the temperature inside the passenger compartment by blowing cold or hot air into it. The motor is used to drive the operation of various components within the system; The battery circuit is used to supply power to all electrical appliances in the system; The expansion tank is used to mitigate system pressure fluctuations caused by volume changes in the coolant due to temperature variations, maintain a certain level of coolant, and expel gas from the pipeline through the vent to ensure that the pipeline is filled with coolant.

2. The electric vehicle thermal management system for R290 refrigerant according to claim 1, characterized in that, The refrigerant circuit includes a compressor, a water-cooled condenser, an electronic expansion valve, a refrigeration unit, and a gas-liquid separator. The above components are connected by refrigerant pipelines, and the R290 refrigerant flows in the refrigerant pipelines. The compressor, water-cooled condenser, electronic expansion valve, refrigeration unit, and gas-liquid separator are connected in sequence via refrigerant pipelines, and the gas-liquid separator is connected to the compressor via a refrigerant pipeline.

3. A thermal management system for electric vehicles using R290 refrigerant according to claim 2, characterized in that, The compressor compresses R290 refrigerant into a high-temperature, high-pressure gas and drives the flow of R290 refrigerant. The water-cooled condenser condenses and dissipates the high-temperature, high-pressure R290 refrigerant gas, converting it into a low-temperature, low-pressure liquid or gas-liquid mixture. The electronic expansion valve throttles the output of the R290 refrigerant liquid or gas-liquid mixture. The refrigerator can convert the R290 refrigerant liquid or gas-liquid mixture into a medium-temperature, low-pressure fluid through heat exchange. The gas-liquid separator retains the liquid refrigerant, ensuring that the refrigerant re-enters the compressor in gaseous form to achieve the compression process.

4. A thermal management system for electric vehicles using R290 refrigerant according to claim 3, characterized in that, The refrigeration unit is connected to a first four-way valve via a coolant pipeline. The water-cooled condenser and the refrigeration unit are respectively connected to different interfaces of the first four-way valve. A first electronic water pump is installed between the water-cooled condenser and the first four-way valve, and a second electronic water pump is installed between the refrigeration unit and the first four-way valve. The end of the refrigeration unit away from the first four-way valve is also connected to a second four-way valve via a coolant pipe. The water-cooled condenser and the refrigeration unit are respectively connected to different interfaces of the second four-way valve.

5. A thermal management system for electric vehicles using R290 refrigerant according to claim 4, characterized in that, The other two ports on the first four-way valve are connected to the vehicle heat exchanger assembly and the radiator respectively through coolant pipes. A first three-way valve is provided between the first four-way valve and the vehicle heat exchanger assembly. The first four-way valve and the vehicle heat exchanger assembly are respectively connected to the two ports of the first three-way valve. A second three-way valve is provided between the first four-way valve and the radiator. The first four-way valve and the radiator are respectively connected to the two ports of the second three-way valve. The other two ports on the second four-way valve are connected to the motor and the vehicle heat exchanger assembly respectively via coolant pipes; The motor and radiator are connected via coolant pipes.

6. A thermal management system for electric vehicles using R290 refrigerant according to claim 5, characterized in that, The in-vehicle heat exchanger assembly includes a first in-vehicle heat exchanger and a second in-vehicle heat exchanger. The first in-vehicle heat exchanger and the second in-vehicle heat exchanger are connected in sequence via coolant pipes. The end of the first in-vehicle heat exchanger away from the second in-vehicle heat exchanger is connected to a first three-way valve, and the end of the second in-vehicle heat exchanger away from the first in-vehicle heat exchanger is connected to the interface of a second four-way valve. A fan is installed outside the first in-vehicle heat exchanger and the second in-vehicle heat exchanger. The air blown out by the fan must pass through the first in-vehicle heat exchanger and the second in-vehicle heat exchanger before entering the passenger compartment.

7. A thermal management system for electric vehicles using R290 refrigerant according to claim 6, characterized in that, Another port on the second three-way valve is connected to the coolant pipe between the motor and the radiator via a coolant pipe.

8. A thermal management system for electric vehicles using R290 refrigerant according to claim 7, characterized in that, One end of the expansion tank is connected to the end of the radiator away from the motor via a coolant pipe, and the other end is connected via a coolant pipe to the coolant pipe between the first three-way valve and the first in-vehicle heat exchanger, the coolant pipe between the second electronic water pump and the refrigeration unit, and the coolant pipe between the first electronic water pump and the water-cooled condenser.

9. A thermal management system for electric vehicles using R290 refrigerant according to claim 8, characterized in that, Another port on the first three-way valve is connected to the battery circuit, and the end of the battery circuit away from the first three-way valve is connected to the coolant pipe between the second vehicle heat exchanger and the second four-way valve.

10. A thermal management system for electric vehicles using R290 refrigerant according to claim 6, 7, 8 or 9, characterized in that, Both the first and second in-vehicle heat exchangers are microchannel heat exchangers.

Images