System and method for improving endurance of pure electric vehicle under extremely cold condition

Abstract

The invention belongs to the technical field of pure electric vehicles, and relates to a system for improving endurance of a pure electric vehicle under an extremely cold condition. The invention further relates to a method for improving endurance of the pure electric vehicle under the extremely cold condition. When the temperature of the circulating medium is greater than or equal to 70 DEG C, the PTC (05) stops working, and at the moment, all heat is provided by the fuel heater (04), so that an HVAC (01) and a battery pack (08) in a passenger compartment are heated while the PTC (05) is heated, and the HVAC (01) and the battery pack (08) are heated while the fuel heater (04) is heated; the circulating medium is controlled by an electronic three-way valve (06), and one part of the circulating medium enters an HVAC (01) of a passenger compartment to heat the interior of the passenger compartment; and one part of the battery pack (08) is heated through the chiller (07). According to the system and method for improving the endurance of the pure electric vehicle under the extremely cold condition, under the extremely cold condition, the comfort in the vehicle can be guaranteed, meanwhile, the power battery is heated, the discharge rate and sufficient discharge of the power battery under the extremely cold condition are guaranteed, and the endurance mileage of the electric vehicle is increased.

Description

Technical Field

[0001] The present invention belongs to the technical field of pure electric vehicles, and more specifically, relates to a system for improving the endurance of a pure electric vehicle in extremely cold conditions. The present invention also relates to a method for improving the endurance of a pure electric vehicle in extremely cold conditions. Background Art

[0002] As the global energy shortage and environmental pollution problems become increasingly serious, more and more automobile manufacturers are focusing their research and development on electric vehicles. Because of their economic, environmental and low pollution characteristics, the development of electric vehicles is currently an effective way to achieve energy conservation, emission reduction and low-carbon travel. However, due to the low temperature in winter in northern regions, pure electric vehicles need to heat the interior of the car and the battery when starting. The battery discharges too quickly and the battery life is greatly reduced. Therefore, there is an urgent need for a method to improve the range of pure electric vehicles in extremely cold regions. Specifically, the current thermal management system of pure electric vehicles has the following problems: 1. The temperature in the north is low in winter, and the battery discharge rate is low and the discharge is insufficient at low temperatures. The use of PTC to heat the passenger compartment and battery pack will increase the consumption of battery power and seriously affect the battery life. 2. At present, even if some thermal management systems use heat pump systems for heating, the main working range of the existing heat pump air conditioner performance is in areas with an ambient temperature of more than -10°C. The heat pump air conditioner is almost ineffective under ambient temperature conditions of about -30°C, and the heat pump system structure and principle are complex and the cost is high. Therefore, there is technical space for improvement in the existing technology.

[0003] There is a technology in the prior art named "A constant temperature device for a battery system of a pure electric vehicle based on air conditioning technology" and with a publication (announcement) number of "CN204943760U". This technology discloses a constant temperature device for a battery system of a pure electric vehicle based on air conditioning technology, including a battery compartment, a condenser, a compressor, an expansion valve, an air conditioning system, an evaporator, a controller and a heater. The heater is located directly below the battery compartment. The controller is connected to the condenser, the compressor, the expansion valve, the air conditioning system and the evaporator through an electromagnetic valve. The controller is also connected to a buffer sensor. The utility model heats up the battery of an electric vehicle in extremely cold areas in winter, slows down its discharge rate in a low temperature environment, and increases the cruising range. It cools down the battery in high temperature areas in summer, slows down the aging rate of its internal unit in a high temperature environment, and extends its service life. It has extremely strong environmental adaptability and provides the necessary guarantee for the use of electric vehicles in all-weather temperature environments.

[0004] However, this technology does not involve the technical problems and technical solutions of the present application. Summary of the invention

[0005] The technical problem to be solved by the present invention is: in view of the deficiencies of the existing technology, a method for improving the endurance of pure electric vehicles in extreme cold conditions is provided which has simple steps and can meet the requirements of ensuring the comfort inside the vehicle under extreme cold conditions, while heating the power battery at the same time, ensuring the discharge rate and sufficient discharge of the power battery under extreme cold conditions, and improving the endurance of electric vehicles.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is:

[0007] The present invention provides a method for improving the driving range of a pure electric vehicle in extremely cold conditions. The method for improving the driving range of a pure electric vehicle in extremely cold conditions comprises a passenger compartment and a battery pack heating step and a passenger compartment heating step. The passenger compartment and battery pack heating step is as follows:

[0008] S1. In extremely cold conditions, when the vehicle is cold-started, the fuel heater is turned on. It takes several minutes for the fuel heater to warm up before stable combustion. During the warm-up process, the fuel heater provides little heat, and the PTC provides heat to the HVAC01 and battery pack;

[0009] S2. When the circulating medium temperature is ≥70℃, the PTC stops working. At this time, all the heat is provided by the fuel heater 04. The electronic three-way valve is a proportional valve, which can heat the HVAC and battery pack of the passenger compartment when the PTC05 is heating, and can also heat the passenger compartment and the battery pack when the fuel heater is heating;

[0010] S3. The circulating medium heated by the PTC or fuel heater is controlled by an electronic three-way valve. A part of it goes to the HVAC of the passenger compartment to heat the passenger compartment to ensure the comfort of the passenger compartment; a part of it goes to the chiller to heat the battery pack to ensure the discharge rate and full discharge of the battery, thereby improving the vehicle's cruising range.

[0011] The passenger compartment heating steps are as follows:

[0012] S1. Under normal conditions, combined with the technical characteristics of the battery pack, the battery pack does not need to be heated. At this time, it is only necessary to heat the HVAC01 of the passenger compartment through PTC05; S2. Under extremely cold conditions, when the vehicle is started, since the fuel heater needs a preheating process time before stable combustion, the fuel heater 04 provides less heat during the preheating process. During this process, PTC provides heat to the HVAC of the passenger compartment; S3. When the circulating medium temperature is ≥70℃, PTC stops working. At this time, all the heat is provided by the fuel heater. Since only the HVAC of the passenger compartment needs to be heated under this condition, the flow through the battery pack circuit and the flow through the HVAC circuit of the passenger compartment can be closed by controlling the electronic three-way valve.

[0013] The temperature range of the extreme cold conditions is between 0°C and -20°C.

[0014] Under normal conditions, PTC heats and the fuel heater stops working; the temperature range under normal conditions is between 20℃ and 0℃.

[0015] The fuel of the fuel heater is diesel.

[0016] Under normal conditions, the low-temperature circulating medium enters the first pipeline of the heat exchanger, and then enters the battery pack through the first circulating medium of the first pipeline. After cooling the battery pack, the high-temperature circulating medium flowing out enters the second pipeline of the heat exchanger for cooling. The circulating medium cooled through the second pipeline then enters the main pipeline where the fuel heater, PTC, and electronic three-way valve are installed, and then enters the heat exchanger.

[0017] The present invention also relates to a system for improving the extreme cold conditions endurance of pure electric vehicles, which has a simple structure and can meet the requirements of ensuring the comfort of the vehicle interior under extreme cold conditions, while heating the power battery at the same time, ensuring the discharge rate and full discharge of the power battery under extreme cold conditions, and improving the endurance of electric vehicles. The system for improving the extreme cold conditions endurance of pure electric vehicles includes HVAC (Heating, Ventilation and Air Conditioning, air conditioning system), an electronic water pump, a fuel heater, a PTC, an electronic three-way valve, a heat exchanger (chiller), a battery pack, a first electronic water pump, and a second electronic circulation pump. The fuel heater, the PTC, and the electronic three-way valve are arranged on the main pipeline. The electronic three-way valve simultaneously connects the first pipeline of the heat exchanger and the HVAC of the passenger compartment. The first pipeline of the fuel heater is connected to the battery pack. The battery pack is simultaneously connected to the second pipeline of the heat exchanger. The second pipeline of the heat exchanger is connected to the main pipeline, and the HVAC is connected to the main pipeline.

[0018] The battery pack and the heat exchanger are connected via a pipeline, and a second expansion tank and a second electronic circulation pump are arranged on the pipeline connecting the battery pack and the heat exchanger.

[0019] The HVAC and the main pipeline are connected through a pipeline, and a first expansion tank and a first electronic circulation pump are arranged on the pipeline connecting the HVAC and the main pipeline.

[0020] The fuel heater, PTC, electronic three-way valve, first electronic circulation pump and second electronic circulation pump are respectively connected to the vehicle control components.

[0021] The technical solution of the present invention is adopted, and the working principle and beneficial effects are as follows:

[0022] The system for improving the endurance of pure electric vehicles in extremely cold conditions described in the present invention is aimed at the driving of electric vehicles under special conditions, that is, solving the problems faced under extremely cold conditions. When the vehicle is cold-started under certain conditions, the fuel heater is turned on. The fuel heater is a component that heats the circulating medium by burning fuel. It is arranged on the main line. When not working, it does not affect the circulation of the circulating medium. When working, it is used to heat the circulating medium. In extremely cold conditions, because the fuel heater requires a preheating process time of several minutes before stable combustion, the fuel heater generates less heat during the preheating process and provides less heat. At this time, heat is generated by PTC. PTC is a component that heats the circulating medium by electricity. It is arranged on the main line. When not working, it does not affect the circulation of the circulating medium. When working, it is used to heat the circulating medium. PTC provides heat to HVAC and battery pack; when the fuel heater is preheated, it can fully provide heat. When the circulating medium temperature of the pipeline is ≥70℃, the control component controls PTC to stop working. At this time, all the heat is provided by the fuel heater. The electronic three-way valve is a proportional valve. When HVAC and battery pack need to heat the room at the same time, the pipelines leading to HVAC and battery pack are all opened, so that HVAC01 and battery pack in the passenger compartment are heated at the same time when PTC is heated. After PTC stops working, HVAC and battery pack can also be heated at the same time when the fuel heater is heated; the circulating medium heated by PTC or fuel heater is controlled by the electronic three-way valve, and a part of it goes to the HVAC in the passenger compartment to heat the passenger compartment to ensure the comfort of the passenger compartment; a part of it is heated to the battery pack through the chiller to ensure the discharge rate and full discharge of the battery, and improve the vehicle's cruising range. The method of the present invention uses a fuel heater to heat the passenger compartment and the battery when driving in an area with extremely cold conditions. Under normal conditions, PTC can provide heating, which can not only ensure the comfort in the car, but also ensure the discharge rate and full discharge of the battery, and improve the cruising range of the whole vehicle; under extremely cold conditions, PTC heating cannot meet the demand, and a fuel heater is required at this time. The electronic three-way valve can control the on and off of the fuel heater and PTC, which can heat the passenger compartment and battery pack at the same time, or heat one of the circuits separately, thereby effectively meeting the needs under different working conditions and having a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The following is a brief description of the contents and symbols in the drawings of this specification:

[0024] Figure 1 This is a schematic diagram of the structure of the system for improving the endurance of a pure electric vehicle in extreme cold conditions according to the present invention;

[0025] The markings in the attached drawings are: 01, HVAC; 02, first expansion tank; 03, first electronic circulation pump; 04, fuel heater; 05, PTC (PTC heater); 06, electronic three-way valve; 07, heat exchanger (chiller); 08, battery pack; 09, second expansion tank; 10, second electronic circulation pump. DETAILED DESCRIPTION

[0026] The following is a further detailed description of the specific implementation of the present invention, such as the shape, structure, mutual position and connection relationship between the various components involved, the function and working principle of each part, etc., through the description of the embodiments with reference to the accompanying drawings:

[0027] As attached Figure 1 As shown, the present invention is a method for improving the cruising range of a pure electric vehicle in extremely cold conditions, the method for improving the cruising range of a pure electric vehicle in extremely cold conditions comprises a passenger compartment and a battery pack heating step at the same time and a passenger compartment heating step, the passenger compartment and battery pack heating step at the same time is:

[0028] S1. When the vehicle is cold-started under extremely cold conditions, the fuel heater 04 is turned on. The fuel heater 04 needs several minutes of preheating time before stable combustion. During the preheating process, the fuel heater 04 provides less heat, and PTC05 provides heat to HVAC01 and battery pack 08; S2. When the temperature of the circulating medium is ≥70℃, PTC05 stops working. At this time, all the heat is provided by the fuel heater 04. The electronic three-way valve 06 is a proportional valve, which can heat the HVAC01 and battery pack 08 in the passenger compartment when PTC05 is heated, and can also heat the HVAC01 and battery pack 08 when the fuel heater 04 is heated; S3. The circulating medium heated by PTC05 or fuel heater 04 is controlled by the electronic three-way valve 06. A part of it goes to the HVAC01 in the passenger compartment to heat the passenger compartment to ensure the comfort of the passenger compartment; a part of it is heated to the battery pack 08 through chiller07 to ensure the discharge rate and full discharge of the battery, and improve the vehicle's cruising range. The above structure proposes an improved technical solution for the deficiencies in the prior art. The technical solution of the present invention is aimed at solving the problems faced by electric vehicles when driving under special conditions, that is, under extremely cold conditions. When the vehicle is cold-started under certain conditions, the fuel heater 04 is turned on. The fuel heater 04 is a component that heats the circulating medium by burning fuel. It is arranged on the main line. When not working, it does not affect the circulation of the circulating medium. When working, it is used to heat the circulating medium. Under extremely cold conditions, because the fuel heater 04 requires a preheating process of several minutes before stable combustion, the fuel heater 04 generates less heat during the preheating process and provides less heat. At this time, heat is generated by PTC05. PTC05 is a component that heats the circulating medium by electricity. It is arranged on the main line. When not working, it does not affect the circulation of the circulating medium. When working, it is used to heat the circulating medium. PTC05 provides heat to HVAC01 and battery pack 08. When the fuel heater 04 is preheated, it can fully provide heat. When the circulating medium temperature of the pipeline is ≥70℃, the control component controls PTC05 to stop working. At this time, all the heat is provided by the fuel heater 04. The electronic three-way valve 06 is a proportional valve. When HVAC01 and battery pack 08 need to heat the room at the same time, the pipelines leading to HVAC01 and battery pack 08 are all opened to achieve simultaneous heating of HVAC01 and battery pack 08 in the passenger compartment when PTC05 is heating. After PTC05 stops working, it can also achieve simultaneous heating of HVAC01 and battery pack 08 when the fuel heater 04 is heating. The circulating medium heated by PTC05 or fuel heater 04 is controlled by the electronic three-way valve 06. A part of it goes to the HVAC01 in the passenger compartment to heat the passenger compartment to ensure the comfort of the passenger compartment; a part of it is heated to the battery pack 08 through chiller07 to ensure the discharge rate and full discharge of the battery, thereby improving the vehicle's cruising range. The method of the present invention uses a fuel heater to heat the passenger compartment and the battery when driving in an area with extremely cold conditions.Under normal conditions, PTC can provide heating, which can ensure the comfort inside the car, and at the same time ensure the discharge rate and full discharge of the battery, thereby improving the cruising range of the vehicle; in extremely cold conditions, PTC05 heating cannot meet the demand, and fuel heater 04 is required for heating. The fuel heater and PTC can be controlled by the electronic three-way valve, which can heat the passenger compartment and the battery pack at the same time, or heat one of the circuits separately, thereby meeting the needs under different working conditions and having a wide range of applications. The method for improving the cruising range of pure electric vehicles under extremely cold conditions described in the present invention has simple steps, can meet the requirements of ensuring the comfort inside the car under extremely cold conditions, and at the same time heat the power battery, ensure the discharge rate and full discharge of the power battery under extremely cold conditions, thereby improving the cruising range of electric vehicles.

[0029] The passenger compartment heating steps are as follows: S1. Under normal conditions, combined with the technical characteristics of the battery pack, the battery pack 08 does not need to be heated. At this time, it is only necessary to heat the HVAC01 of the passenger compartment through HVAC01; S2. Under extremely cold conditions, when the vehicle is started, since the fuel heater 04 needs a preheating process time before stable combustion, the fuel heater 04 provides less heat during the preheating process. During this process, PTC05 provides heat to the HVAC01 of the passenger compartment; S3. When the circulating medium temperature is ≥70°C, PTC05 stops working. At this time, all the heat is provided by the fuel heater 04. Since only the HVAC01 of the passenger compartment needs to be heated under this condition, the flow through the battery pack 08 circuit and the flow through the HVAC01 circuit of the passenger compartment can be closed by controlling the electronic three-way valve 06. The steps of the present invention can not only meet the needs of heating the HVAC01 of the passenger compartment of the vehicle under normal conditions, but also meet the needs of PTC05 to provide heat to the HVAC01 of the passenger compartment under extremely cold conditions, and at the same time meet the needs of PTC05 to provide heat to the HVAC01 of the passenger compartment and the battery pack 08 at the same time, effectively realize the heating of the passenger compartment and ensure the comfort of the passenger compartment; at the same time, the battery pack (08) can be heated to ensure the discharge rate and full discharge of the battery, and improve the vehicle's cruising range. In this way, the overall performance of the electric vehicle is effectively improved.

[0030] The temperature range of the extreme cold condition is between 0°C and -20°C. Under normal conditions, PTC05 performs heating and the fuel heater 04 stops working; the temperature range of the normal condition is between 20°C and 0°C. The fuel of the fuel heater 04 is diesel.

[0031] Under normal conditions, the low-temperature circulating medium enters the first pipeline of the heat exchanger 07, and then enters the battery pack 08 through the first circulating medium of the first pipeline. After cooling the battery pack 08, the high-temperature circulating medium flowing out enters the second pipeline of the heat exchanger 07 for cooling. The circulating medium cooled through the second pipeline then enters the main pipeline with the fuel heater 04, PTC05, and electronic three-way valve 06, and then enters the heat exchanger 07. In the above steps, the battery pack is heated by the high-temperature circulating medium under extremely cold conditions, and the battery pack is cooled by the low-temperature circulating medium when the temperature is high. This satisfies the driving of electric vehicles in different environments and reduces the impact of temperature. The circulation of the circulating medium is achieved through the first electronic circulating pump and the second electronic circulating pump.

[0032] The present invention also relates to a system for improving the extreme cold conditions endurance of pure electric vehicles, which has a simple structure and can meet the requirements of ensuring the comfort of the vehicle interior under extreme cold conditions, heating the power battery at the same time, ensuring the discharge rate and full discharge of the power battery under extreme cold conditions, and improving the endurance of the electric vehicle. The system for improving the extreme cold conditions endurance of pure electric vehicles includes HVAC01, an electronic water pump 03, a fuel heater 04, a PTC05, an electronic three-way valve 06, a chiller 07, a battery pack 08, a first electronic water pump 10, and a second electronic circulation pump 10. The fuel heater 04, the PTC05, and the electronic three-way valve 06 are arranged on the main pipe. The electronic three-way valve 06 simultaneously connects the first pipe of the heat exchanger 07 and the HVAC01 of the passenger compartment. The first pipe of the fuel heater 07 is connected to the battery pack 08. The battery pack 08 is simultaneously connected to the second pipe of the heat exchanger 07. The second pipe of the heat exchanger 07 is connected to the main pipe, and the HVAC01 is connected to the main pipe. With the above structure, under extremely cold conditions, when the fuel heater 04 is fully operational, heat is generated to supply heating to the passenger compartment and is also used to heat the battery pack, thereby increasing the vehicle's cruising range.

[0033] The battery pack 08 and the heat exchanger 07 are connected through a pipeline, and a second expansion tank 09 and a second electronic circulation pump 10 are arranged on the pipeline connecting the battery pack 08 and the heat exchanger 07. The HVAC01 and the main pipeline are connected through a pipeline, and a first expansion tank 02 and a first electronic circulation pump 03 are arranged on the pipeline connecting the HVAC01 and the main pipeline. The fuel heater 04, PTC05, electronic three-way valve 06, first electronic circulation pump 03, and second electronic circulation pump 10 are respectively connected to the vehicle control components. With the above structure, the control component can reliably control the start and stop of the fuel heater 04, PTC05, electronic three-way valve 06, first electronic circulation pump 03, and second electronic circulation pump 10, thereby achieving the purpose of different components intervening in work under different conditions.

[0034] The system for improving the endurance of pure electric vehicles in extremely cold conditions described in the present invention has a separate control panel for the fuel heater to control the switch. The fuel heater should be safety checked before it is turned on. The fuel heater is a prior art. There must be oil in the fuel heater for normal ignition. If a fault occurs during the heating process, the indicator light will flash to indicate the cause of the fault. At this time, it is necessary to stop heating and investigate the specific fault problem. The fuel heater can be used again after the problem is solved. The fuel used in the fuel heater of the present invention is diesel. Because diesel has low volatility and a high ignition point, it usually needs to be ignited by an open flame in an environment of 80°C to 120°C. Therefore, diesel is selected as the fuel, which is safer. Furthermore, different grades of diesel are applicable to different ambient temperatures, but the application range of higher grade diesel can cover that of lower grade diesel, and has a wide range of applications.

[0035] The system for improving the driving range of pure electric vehicles in extremely cold conditions described in the present invention is to add a fuel heater to the pure electric vehicle in series in the warm air circuit. In extremely cold conditions, the passenger compartment and the battery pack are heated. The PTC requires electricity to work, and the fuel heater replaces the PTC most of the time to reduce battery power consumption, ensure the comfort in the car, and improve the driving range of the whole vehicle. The electronic three-way valve used in this system is a proportional valve, which distributes the flow according to the heat demand of each circuit. The fuel heater needs to be filled with different brands of diesel within the applicable range under different environmental conditions.

[0036] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A method for improving the endurance of a pure electric vehicle in extreme cold conditions, characterized by: The method for improving the driving range of a pure electric vehicle in extreme cold conditions includes a passenger compartment and a battery pack heating step and a passenger compartment heating step. The passenger compartment and battery pack heating step is: S1. In extremely cold conditions, when the vehicle is cold-started, the fuel heater (04) is turned on. The fuel heater (04) requires several minutes of preheating time before stable combustion. During the preheating process, the fuel heater (04) provides less heat, and the PTC (05) provides heat to the HVAC (01) and the battery pack (08); S2. When the temperature of the circulating medium is ≥70°C, the PTC (05) stops working. At this time, all the heat is provided by the fuel heater (04). The electronic three-way valve (06) is a proportional valve, which can heat the HVAC (01) and the battery pack (08) of the passenger compartment when the PTC (05) is heated, and can also heat the HVAC (01) and the battery pack (08) when the fuel heater (04) is heated; S3. The circulating medium heated by the PTC (05) or the fuel heater (04) is controlled by an electronic three-way valve (06). A part of the circulating medium is sent to the HVAC (01) of the passenger compartment to heat the passenger compartment to ensure the comfort of the passenger compartment; and a part of the circulating medium is sent to the chiller (07) to heat the battery pack (08) to ensure the discharge rate and full discharge of the battery, thereby improving the vehicle's cruising range.

2. The method for improving the endurance of a pure electric vehicle in extreme cold conditions according to claim 1, characterized in that: The passenger compartment heating steps are as follows: S1. Under normal conditions, combined with the technical characteristics of the battery pack, the battery pack (08) does not need to be heated. In this case, only the HVAC (01) of the passenger compartment needs to be heated through the PTC (05); S2. Under normal conditions, when the vehicle is started, the fuel heater (04) needs a preheating period before stable combustion. During the preheating period, the fuel heater (04) provides less heat. During this period, the PTC (05) provides heat to the HVAC (01) of the passenger compartment. S3. When the temperature of the circulating medium is ≥70°C, the PTC (05) stops working. At this time, all the heat is provided by the fuel heater (04). Under this condition, only the HVAC (01) of the passenger compartment needs to be heated. By controlling the electronic three-way valve (06), the flow through the battery pack (08) circuit is closed and the flow through the HVAC (01) circuit of the passenger compartment is opened.

3. The method for improving the endurance of a pure electric vehicle in extreme cold conditions according to claim 1 or 2, characterized in that: The temperature range of the extreme cold conditions is between 0°C and -20°C.

4. The method for improving the endurance of a pure electric vehicle in extreme cold conditions according to claim 2, characterized in that: Under normal conditions, the battery pack (08) does not need to be heated; only the passenger compartment needs to be heated; the temperature range under normal conditions is between 20°C and 0°C.

5. The method for improving the endurance of a pure electric vehicle in extreme cold conditions according to claim 1 or 2, characterized in that: The fuel of the fuel heater (04) is diesel.

6. The method for improving the endurance of a pure electric vehicle in extreme cold conditions according to claim 2, characterized in that: Under normal conditions, the low-temperature circulating medium enters the first pipeline of the heat exchanger (07), the first circulating medium passing through the first pipeline enters the battery pack (08), the high-temperature circulating medium flowing out after cooling the battery pack (08) enters the second pipeline of the heat exchanger (07) for cooling, the circulating medium cooled through the second pipeline enters the main pipeline provided with the fuel heater (04), the PTC (05), and the electronic three-way valve (06), and then enters the heat exchanger (07).

7. A system for improving the endurance of a pure electric vehicle in extreme cold conditions, characterized by: The invention comprises an HVAC (01), an electronic water pump (03), a fuel heater (04), a PTC (05), an electronic three-way valve (06), a chiller (07), a battery pack (08), a first electronic water pump (10), and a second electronic circulation pump (10); the fuel heater (04), the PTC (05), and the electronic three-way valve (06) are arranged on a main pipeline; the electronic three-way valve (06) is connected to a first pipeline of a heat exchanger (07) and the HVAC (01) of a passenger compartment at the same time; the first pipeline of the fuel heater (07) is connected to the battery pack (08); the battery pack (08) is connected to a second pipeline of the heat exchanger (07); the second pipeline of the heat exchanger (07) is connected to the main pipeline; and the HVAC (01) is connected to the main pipeline.

8. The system for improving the endurance of pure electric vehicles in extreme cold conditions according to claim 7 is characterized in that: The battery pack (08) and the heat exchanger (07) are connected via a pipeline, and a second expansion tank (09) and a second electronic circulation pump (10) are arranged on the pipeline connecting the battery pack (08) and the heat exchanger (07).

9. The system for improving the endurance of a pure electric vehicle in extreme cold conditions according to claim 7 or 8, characterized in that: The HVAC (01) and the main pipeline are connected via a pipeline, and a first expansion tank (02) and a first electronic circulation pump (03) are arranged on the pipeline connecting the HVAC (01) and the main pipeline.

10. The system for improving the endurance of pure electric vehicles in extreme cold conditions according to claim 9, characterized in that: The fuel heater (04), PTC (05), electronic three-way valve (06), first electronic circulation pump (03) and second electronic circulation pump (10) are respectively connected to the vehicle control components.

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