Heat pump system for pure electric vehicle

Abstract

The utility model relates to a heat pump system for a pure electric vehicle, and belongs to the technical field of vehicle heat management. Comprising a compressor, an in-vehicle refrigerant section, a motor refrigerant section and a battery refrigerant section are sequentially connected to a pipeline between the output side and the input side of the compressor in series, the in-vehicle refrigerant section and the motor refrigerant section which are connected in series are further connected with an out-vehicle refrigerant branch in parallel, and the battery refrigerant section is further connected with an in-vehicle refrigeration branch and a bypass branch in parallel. And the in-vehicle refrigeration branch and the bypass branch are connected in parallel. Motor waste heat can be independently utilized or the motor waste heat and battery waste heat can be simultaneously utilized for cab air conditioner heating circulation, cab heating energy consumption is effectively reduced, and the endurance mileage of a vehicle is increased; meanwhile, the motor waste heat and the battery waste heat share the compressor and the condenser, and the motor refrigerant branch and the battery refrigerant branch are connected in series, so that the occupied space can be reduced.

Description

Technical Field

[0001] The utility model relates to a heat pump system for pure electric vehicles, belonging to the technical field of vehicle thermal management. Background Art

[0002] With the rapid development of pure electric vehicles, people pay more attention to the driving range of the whole vehicle, especially pure electric trucks. Limited by the development of battery technology and charging platforms, the high efficiency and energy saving of the air conditioning system of pure electric trucks are one of the main means to improve the driving range of pure electric trucks at present. Therefore, based on the single-cooling air conditioning system commonly used in current pure electric light trucks, the whole vehicle needs a more efficient and energy-saving thermal management system.

[0003] The schematic diagram of the thermal management system of a pure electric light truck in the prior art is as Figure 1 shown. One refrigerant flow path is the cab refrigeration system, that is, a cab refrigeration cycle is formed through a compressor, a condenser, an HVAC (Heating, Ventilation and Air Conditioning) assembly and a gas-liquid separator; the other refrigerant flow path is the battery cooling system, that is, a battery refrigeration cycle is formed through a compressor, a condenser, a chiller (battery cooler) and a gas-liquid separator; among them, the pure electric light truck uses a single-cooling air conditioning system, and the heating of the cab adopts separate air-heating PTC (Positive Temperature Coefficient) heating. Since the heating efficiency (heat output / electricity consumption) of the air-heating PTC < 1, when heating the cab in a low-temperature environment, the power consumption increases. This heating mode has increased energy consumption in a low-temperature environment (such as in winter in the north), seriously reducing the driving range of the vehicle. Moreover, the heating and refrigeration of the cab in this thermal management system are independent of each other, making the utilization rate of the components of the thermal management system relatively low and the system space occupancy high. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a heat pump system for pure electric vehicles to solve the problem of high energy consumption for heating the cab in the existing thermal management system.

[0005] To achieve the above purpose, the solution of the utility model includes:

[0006] A heat pump system for pure electric vehicles of the utility model includes a compressor. A pipeline between the output side and the input side of the compressor is successively connected in series with an in-vehicle refrigerant section, a motor refrigerant section and a battery refrigerant section. The in-vehicle refrigerant section and the motor refrigerant section after being connected in series are also connected in parallel with an out-of-vehicle refrigerant branch. The battery refrigerant section is also connected in parallel with an in-vehicle refrigeration branch and a bypass branch, and the in-vehicle refrigeration branch and the bypass branch are connected in parallel;

[0007] The bypass branch includes a pipeline in series with a first valve;

[0008] The in-vehicle refrigerant section includes a second valve in series and an in-vehicle condenser for heat exchange with the in-vehicle environment in the cab;

[0009] The motor refrigerant section includes a first expansion valve in series and a motor assembly heat exchanger for heat exchange with the motor liquid cooling circulation circuit. The first expansion valve is arranged on the pipeline near the input side of the motor assembly heat exchanger;

[0010] The battery refrigerant section includes a second expansion valve in series and a battery heat exchanger for heat exchange with the battery liquid cooling circulation circuit. The second expansion valve is arranged on the pipeline near the input side of the battery heat exchanger;

[0011] The out-of-vehicle refrigerant branch includes a third valve in series and an out-of-vehicle condenser for heat exchange with the out-of-vehicle environment;

[0012] The in-vehicle refrigeration branch includes a third expansion valve in series and an in-vehicle evaporator for refrigerating the in-vehicle environment in the cab. The third expansion valve is arranged on the pipeline near the input side of the in-vehicle evaporator.

[0013] Furthermore, the first expansion valve, the second expansion valve and the third expansion valve all adopt electronic expansion valves.

[0014] Furthermore, the motor liquid cooling circulation circuit includes a circulating water pump in series, a motor controller heat exchanger for heat exchange with the motor controller, a motor heat exchanger for heat exchange with the motor, a motor radiator for heat exchange with the environment, and a motor assembly heat exchanger. The motor radiator accelerates the heat exchange with the environment through a fan.

[0015] Furthermore, the out-of-vehicle condenser also accelerates the heat exchange with the environment through a fan.

[0016] Furthermore, the motor radiator and the out-of-vehicle condenser are arranged in sequence along the air flow direction of the fan.

[0017] Furthermore, a heater for heating the coolant in the motor liquid cooling circulation circuit is also in series in the motor liquid cooling circulation circuit.

[0018] Furthermore, valves for preventing backflow are respectively arranged on the pipeline between the connection of the output side of the out-of-vehicle condenser and the output side of the motor assembly heat exchanger and the output side of the out-of-vehicle condenser, and on the pipeline between the connection of the output side of the out-of-vehicle condenser and the output side of the motor assembly heat exchanger and the output side of the motor assembly heat exchanger.

[0019] Furthermore, the valve for preventing backflow is arranged close to the connection.

[0020] Furthermore, the valve for preventing backflow is selected as a check valve.

[0021] Furthermore, a solenoid valve is selected as the valve for preventing backflow.

[0022] Advantages of the present utility model:

[0023] The present utility model is a pioneering invention, providing a heat pump system for pure electric vehicles. Specifically, an in-vehicle refrigerant section, a motor refrigerant section, and a battery refrigerant section are sequentially connected in series on the pipeline between the output side and the input side of the compressor. The in-vehicle refrigerant section and the motor refrigerant section after being connected in series are also connected in parallel with an out-of-vehicle refrigerant branch. The battery refrigerant section is also respectively connected in parallel with an in-vehicle refrigeration branch and a bypass branch, and the in-vehicle refrigeration branch and the bypass branch are connected in parallel. The present utility model can separately utilize the waste heat of the motor or simultaneously utilize the waste heat of the motor and the battery to perform a heating cycle for the cab air conditioner, effectively reducing the heating energy consumption of the cab, increasing the vehicle's cruising range, and not affecting the normal use of other thermal management, such as: the separate use of battery refrigeration or cab refrigeration.

[0024] Among them, when only the second valve, the first expansion valve, and the second expansion valve are opened, through the motor assembly heat exchanger that uses the compressor, the in-vehicle condenser, and the first expansion valve as an evaporator, and the battery heat exchanger that uses the compressor, the in-vehicle condenser, and the second expansion valve as an evaporator, a heating cycle for the cab air conditioner is realized by simultaneously utilizing the waste heat of the motor and the battery, effectively reducing the heating energy consumption of the cab and increasing the vehicle's cruising range. At the same time, because the utilization of the waste heat of the motor and the utilization of the waste heat of the battery share the compressor and the condenser, and the motor refrigerant section and the battery refrigerant section are connected in series, it can effectively reduce the space occupation, and by simultaneously utilizing the waste heat of the motor and the battery, the heating energy consumption of the cab can be greatly reduced.

[0025] When only the third valve and the third expansion valve are opened, a refrigeration cycle for the cab is realized by the cooperation of the compressor, the out-of-vehicle condenser, and the third expansion valve with the in-vehicle evaporator.

[0026] When only the third valve and the second expansion valve are opened, a battery refrigeration cycle is realized by the cooperation of the compressor, the out-of-vehicle condenser, and the second expansion valve with the battery heat exchanger used as an evaporator.

[0027] When only the third valve, the third expansion valve, and the second expansion valve are opened, a refrigeration cycle for the cab air conditioner and a battery refrigeration cycle are realized by the cooperation of the compressor, the out-of-vehicle condenser, the third expansion valve with the in-vehicle evaporator, and the second expansion valve with the battery heat exchanger used as an evaporator.

[0028] When only the second valve, the first expansion valve, and the first valve are opened, a heating cycle for the cab air conditioner using the waste heat of the motor is realized by the cooperation of the compressor, the in-vehicle condenser, the first expansion valve with the motor assembly heat exchanger used as an evaporator, and the bypass branch.

[0029] In view of the fact that the motor still generates heat under the condition of cold winter (low temperature), this utility model converts the heat, transports the waste heat of the motor to the cab for heating. This process is to use the waste heat of the motor for the air-conditioning heating of the cab. This process not only uses the waste heat of the motor for the air-conditioning heating of the cab, but also realizes the function of cooling the motor. And under the low temperature condition, the battery also generates heat during operation. In the case that the temperature of the battery body is too high and the battery needs to be cooled, through the conversion of this heat, the waste heat of the battery is transported to the cab for heating. This process is to use the waste heat of the battery for the air-conditioning heating of the cab. This process not only uses the waste heat of the battery for the air-conditioning heating of the cab, but also realizes the function of cooling the battery.

[0030] Among them, the in-vehicle refrigerant section includes a second valve connected in series and an in-vehicle condenser for exchanging heat with the in-vehicle environment; the motor refrigerant section includes a first expansion valve connected in series and a motor assembly heat exchanger for exchanging heat with the motor liquid cooling circuit. The first expansion valve is arranged on the pipeline near the input side of the motor assembly heat exchanger; the battery refrigerant section includes a second expansion valve connected in series and a battery heat exchanger for exchanging heat with the battery liquid cooling circuit. The second expansion valve is arranged on the pipeline near the input side of the battery heat exchanger; the out-of-vehicle refrigerant branch includes a third valve connected in series and an out-of-vehicle condenser for exchanging heat with the out-of-vehicle environment; the in-vehicle refrigeration branch includes a third expansion valve connected in series and an in-vehicle evaporator for cooling the in-vehicle environment. The third expansion valve is arranged on the pipeline near the input side of the in-vehicle evaporator; the bypass branch includes a pipeline connected in series with a first valve, and the first valve is used to connect or cut off the bypass branch. Description of the Drawings

[0031] Figure 1 is a schematic diagram of an existing thermal management system for pure electric vehicles;

[0032] Figure 2 is a schematic diagram of the working principle of an embodiment of the heat pump system for pure electric vehicles of this utility model;

[0033] Figure 3 is a schematic diagram of the working principle of the cab refrigeration mode of an embodiment of the heat pump system of this utility model;

[0034] Figure 4 is a schematic diagram of the working principle of the battery refrigeration mode of an embodiment of the heat pump system of this utility model;

[0035] Figure 5 is a schematic diagram of the working principle of the cab heating mode of an embodiment of the heat pump system of this utility model;

[0036] Figure 6 is a schematic diagram of the working principle of the simultaneous operation of the battery refrigeration mode and the cab heating mode of an embodiment of the heat pump system of this utility model.

[0037] Description of the Reference Numerals:

[0038] 1. Compressor; 2. Third solenoid valve; 3. Out-of-vehicle condenser; 4. First check valve; 5. Third electronic expansion valve; 6. In-vehicle evaporator; 7. Gas-liquid separator; 8. Second electronic expansion valve; 9. First plate heat exchanger; 10. First water pump; 11. Second solenoid valve; 12. In-vehicle condenser; 13. First electronic expansion valve; 14. Second plate heat exchanger; 15. Second water pump; 16. Second check valve; 17. First solenoid valve. Detailed implementation manner

[0039] To solve the problems in the background technology, the present utility model provides a heat pump system for a pure electric vehicle, which integrates the heating cycle of the cab air conditioner, the refrigeration cycle of the driving air conditioner, and the battery refrigeration cycle. The three cycles can be realized separately, or any cycle in the cab (heating or refrigeration) and the battery refrigeration cycle can be realized simultaneously. Among them, the cab heating cycle can separately utilize the waste heat of the motor to reduce the heating energy consumption of the cab, and can also simultaneously utilize the waste heat of the motor and the battery to reduce the heating energy consumption of the cab. On this basis, the utilization rate of components in the system can be improved by sharing the compressor and the condenser, effectively reducing the space occupation.

[0040] To make the purpose, technical solution and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the drawings and embodiments.

[0041] An embodiment of a heat pump system for a pure electric vehicle:

[0042] A heat pump system for a pure electric vehicle includes a compressor. A vehicle interior refrigerant section, a motor refrigerant section, and a battery refrigerant section are sequentially connected in series on the pipeline between the output side and the input side of the compressor (compressor → vehicle interior refrigerant section → motor refrigerant section → battery refrigerant section → compressor). The vehicle interior refrigerant section and the motor refrigerant section after being connected in series are also connected in parallel with an out-of-vehicle refrigerant branch. The battery refrigerant section is also connected in parallel with a vehicle interior refrigeration branch and a bypass branch with a first valve connected in series.

[0043] Among them, the vehicle interior refrigerant section includes a second valve connected in series and an in-vehicle condenser for exchanging heat with the cab environment.

[0044] Among them, the motor refrigerant section includes a first expansion valve connected in series and a motor assembly heat exchanger for exchanging heat with the motor liquid cooling circuit. The first expansion valve for throttling is arranged on the pipeline close to the input side of the motor assembly heat exchanger.

[0045] Among them, the battery refrigerant section includes a second expansion valve connected in series and a battery heat exchanger for exchanging heat with the battery liquid cooling circuit. The second expansion valve for throttling is arranged on the pipeline close to the input side of the battery heat exchanger.

[0046] Among them, the refrigerant branch outside the vehicle includes a third valve and an external condenser in series for heat exchange with the external environment of the vehicle.

[0047] Among them, the refrigeration branch inside the vehicle includes a third expansion valve and an internal evaporator for refrigerating the environment inside the cab. The third expansion valve for throttling is arranged on the pipeline near the input side of the internal evaporator.

[0048] Among them, the first valve is used to connect or cut off the bypass branch.

[0049] When only the second valve, the first expansion valve and the second expansion valve are opened, through the cooperation of the compressor, the internal condenser and the first expansion valve as the motor assembly heat exchanger of the evaporator, and the cooperation of the compressor, the internal condenser and the second expansion valve as the battery heat exchanger of the evaporator, the cab air-conditioning heating cycle is realized by using the waste heat of the motor and the battery waste heat simultaneously.

[0050] When only the third valve and the third expansion valve are opened, through the cooperation of the compressor, the external condenser and the third expansion valve with the internal evaporator, the cab refrigeration cycle is realized.

[0051] When only the third valve and the second expansion valve are opened, through the cooperation of the compressor, the external condenser and the second expansion valve with the battery heat exchanger as the evaporator, the battery refrigeration cycle is realized.

[0052] When only the third valve, the third expansion valve and the second expansion valve are opened, through the cooperation of the compressor, the external condenser, the third expansion valve with the internal evaporator and the second expansion valve with the battery heat exchanger as the evaporator, the cab air-conditioning refrigeration cycle and the battery refrigeration cycle are realized.

[0053] When only the second valve, the first expansion valve and the first valve are opened, through the cooperation of the compressor, the internal condenser, the first expansion valve as the motor assembly heat exchanger of the evaporator and the bypass branch, the cab air-conditioning heating cycle using the waste heat of the motor is realized.

[0054] The utility model avoids the adverse effects on the battery and the cab in the case of only heating the cab by using the waste heat of the motor by connecting the bypass branch.

[0055] The utility model mainly uses the waste heat of the motor for a long-time cab air-conditioning heating cycle, and also uses the waste heat of the motor and the battery waste heat simultaneously for a short-time cab air-conditioning heating cycle under certain conditions.

[0056] Specifically, to make the control reliable and save the control cost, the first expansion valve, the second expansion valve and the third expansion valve all adopt electronic expansion valves.

[0057] More specifically, to make the control reliable and save the control cost, the first valve, the second valve and the third valve all adopt solenoid valves.

[0058] Specifically, the motor liquid cooling circulation circuit includes a circulating water pump connected in series, a motor controller heat exchanger for heat exchange with the motor controller, a motor heat exchanger for heat exchange with the motor, a motor radiator for heat exchange with the environment, and a motor assembly heat exchanger. The motor radiator accelerates the heat exchange with the environment through a fan. Among them, the motor assembly heat exchanger includes the motor heat exchanger and the motor controller heat exchanger, and the motor assembly includes the motor and the motor controller.

[0059] Specifically, the external condenser also accelerates the heat exchange with the environment through the above-mentioned fan. By sharing the fan between the external condenser and the motor radiator, the space occupation is reduced.

[0060] More specifically, the motor radiator and the external condenser are arranged in sequence along the air flow direction of the fan, and the fan can accelerate the cooling of the refrigerant by the external condenser with the help of the motor radiator.

[0061] Specifically, a heater for heating the coolant of the motor liquid cooling circulation circuit is also connected in series in the motor liquid cooling circulation circuit, which can quickly heat the motor waterway (motor liquid cooling circulation circuit) in a low-temperature environment. Because when the vehicle starts, the motor has not yet run, and the too low temperature of the motor waterway will affect the heating performance of the cab. The heater selects a water heating PTC (the figure shows WPTC). The water heating PTC (Positive Temperature Coefficient), that is, the water heating PTC heater is a heating device using a positive temperature coefficient thermistor material.

[0062] Specifically, on the pipeline between the connection of the output side of the external condenser and the output side of the motor assembly heat exchanger and the output side of the external condenser, and on the pipeline between the connection of the output side of the external condenser and the output side of the motor assembly heat exchanger and the output side of the motor assembly heat exchanger, valves for preventing backflow are respectively provided. The valves for preventing backflow select check valves or solenoid valves. To save control costs, a first check valve is provided on the pipeline between the connection of the output side of the external condenser and the output side of the motor assembly heat exchanger and the output side of the external condenser, and a second check valve is provided on the pipeline between the connection of the output side of the external condenser and the output side of the motor assembly heat exchanger and the output side of the motor assembly heat exchanger, effectively preventing the occurrence of backflow phenomena. More specifically, the valves for preventing backflow are arranged close to the connection.

[0063] Such as Figure 2As shown in the figure, the heat pump system mainly includes a compressor 1, a third solenoid valve 2 as the third valve, an external condenser 3, a first check valve 4, a third electronic expansion valve 5 as the third expansion valve, an internal evaporator 6, a gas-liquid separator 7, a second electronic expansion valve 8 as the second expansion valve, a first plate heat exchanger 9 as the battery heat exchanger, a first water pump 10 (the first circulating water pump), a second solenoid valve 11 as the second valve, an internal condenser 12, a first electronic expansion valve 13 as the first expansion valve, a second plate heat exchanger 14 as the motor assembly heat exchanger, a second water pump 15 (the second circulating water pump) as the aforementioned circulating water pump, a second check valve 16, and a first solenoid valve 17 as the first valve.

[0064] Among them, the liquid-cooled sides of the first water pump 10, the battery pack heat exchanger (shown as the battery pack in the figure) for heat exchange with the battery pack, and the first plate heat exchanger 9 in series form a battery liquid-cooling circulation loop.

[0065] The liquid-cooled side of the second plate heat exchanger 14, the second water pump 15, a water heating PTC (water heater, shown as WPTC in the figure) for heating the coolant in the motor liquid-cooling circulation loop, a motor controller heat exchanger (shown as the motor controller in the figure) for heat exchange with the motor controller, a motor heat exchanger (shown as the motor in the figure) for heat exchange with the motor, and a motor radiator for realizing heat exchange between the motor assembly and the environment in series form a motor liquid-cooling circulation loop.

[0066] The input end of the compressor 1 is connected to the output end of the gas-liquid separator 7. A cab refrigeration section is connected in series between the output end of the compressor 1 and the input end of the gas-liquid separator 7. The cab refrigeration section includes a third solenoid valve 2, an external condenser 3, a first check valve 4, a third electronic expansion valve 5, and an internal evaporator 6 connected in series in sequence. The input end of the third solenoid valve 2 is connected to the output end of the compressor 1, and the output end of the internal evaporator 6 is connected to the input end of the gas-liquid separator 7.

[0067] A pipeline between the pipeline between the first check valve 4 and the third electronic expansion valve 5 and the pipeline between the compressor 1 and the third solenoid valve 2 is also connected in series with a second solenoid valve 11, an internal condenser 12, a first electronic expansion valve 13, the refrigerant side of the second plate heat exchanger 14, and a second check valve 16 connected in series in sequence. The output end of the compressor 1 is also connected to the input end of the second solenoid valve 11, and the output end of the second check valve 16 is also connected to the input end of the third electronic expansion valve 5.

[0068] A refrigerant side of a second electronic expansion valve 8 and a first plate heat exchanger 9 connected in series in sequence is further connected in series between a pipeline between the first check valve 4 and the third electronic expansion valve 5 and a pipeline between the in-vehicle evaporator 6 and the gas-liquid separator 7. An input end of the second electronic expansion valve 8 is communicated with an output end of the second check valve 16 or the input end of the second electronic expansion valve 8 is communicated with an output end of the first check valve 4. An input end of the gas-liquid separator 7 is further communicated with an output end of the refrigerant side of the first plate heat exchanger 9.

[0069] A first solenoid valve 17 is further connected in series between a pipeline between the first check valve 4 and the third electronic expansion valve 5 and a pipeline between the in-vehicle evaporator 6 and an input end of the gas-liquid separator 7. An input end of the first solenoid valve 17 is communicated with an output end of the second check valve 16 or the input end of the first solenoid valve 17 is communicated with an output end of the first check valve 4. An input end of the gas-liquid separator 7 is further communicated with an output end of the first solenoid valve 17.

[0070] Among them, as Figure 3 shown, when only the third solenoid valve 2, the first check valve 4, and the third electronic expansion valve 5 are opened, the refrigerant flows through the compressor 1 in sequence through the third solenoid valve 2, the out-of-vehicle condenser 3, the first check valve 4, the third electronic expansion valve 5, the in-vehicle evaporator 6, and the gas-liquid separator 7 and then flows back to the compressor 1. While absorbing heat from the high-temperature and high-pressure gas (refrigerant) output by the compressor 1 through the out-of-vehicle condenser 3 and releasing heat to the out-of-vehicle environment, the cooled refrigerant (coolant) is output. Then, while the coolant evaporates (releases heat) through the in-vehicle evaporator 6, the environment inside the cab is cooled, thereby realizing the refrigeration of the cab, that is, the cab refrigeration mode is turned on.

[0071] Among them, as Figure 4 shown, when only the third solenoid valve 2, the first check valve 4, and the second electronic expansion valve 8 are opened, the refrigerant flows through the compressor 1 in sequence through the third solenoid valve 2, the out-of-vehicle condenser 3, the first check valve 4, the second electronic expansion valve 8, the refrigerant side of the first plate heat exchanger 9, and the gas-liquid separator 7 and then flows back to the compressor 1. While absorbing heat from the high-temperature and high-pressure gas output by the compressor 1 through the out-of-vehicle condenser 3 and releasing heat to the out-of-vehicle environment, the cooled refrigerant (coolant) is output. Then, the coolant in the battery liquid cooling circulation loop is cooled by the heat exchange between the refrigerant side and the liquid cooling side of the first plate heat exchanger 9, thereby realizing the refrigeration of the battery, that is, the battery refrigeration mode is turned on.

[0072] Among them, as Figure 5As shown, when only the second solenoid valve 11, the first electronic expansion valve 13, the second check valve 16, and the first solenoid valve 17 are opened, the refrigerant flows through the compressor 1 in sequence, then through the second solenoid valve 11, the in-vehicle condenser 12, the first electronic expansion valve 13, the refrigerant side of the second plate heat exchanger 14, the second check valve 16, the first solenoid valve 17, and the gas-liquid separator 7, and then flows back to the compressor 1. While absorbing heat from the high-temperature and high-pressure gas output by the compressor 1 through the in-vehicle condenser 12 and releasing heat to the cab environment, the cooled refrigerant (coolant) is output. Then, through the heat exchange between the refrigerant side and the liquid-cooled side of the second plate heat exchanger 14, the heat exchange between the coolant and the coolant carrier in the motor liquid-cooling circulation loop is realized. It not only heats the cab environment through the in-vehicle condenser 12, but also uses the waste heat of the motor in the pipeline where the first solenoid valve 17 is located in the cab to heat the cab, that is, the cab heating mode is turned on.

[0073] Among them, as Figure 6 shown, when only the second solenoid valve 11, the first electronic expansion valve 13, the second check valve 16, and the second electronic expansion valve 8 are opened, the refrigerant flows through the compressor 1 in sequence, then through the second solenoid valve 11, the in-vehicle condenser 12, the first electronic expansion valve 13, the refrigerant side of the second plate heat exchanger 14, the second check valve 16, the second electronic expansion valve 8, the refrigerant side of the first plate heat exchanger 9, and the gas-liquid separator 7, and then flows back to the compressor 1. While absorbing heat from the high-temperature and high-pressure gas output by the compressor 1 through the in-vehicle condenser 12 and releasing heat to the cab environment, the cooled refrigerant (coolant) is output. Then, through the heat exchange between the refrigerant side and the liquid-cooled side of the second plate heat exchanger 14, the heat exchange between the coolant and the coolant carrier in the motor liquid-cooling circulation loop is realized. Also, through the heat exchange between the refrigerant side and the liquid-cooled side of the first plate heat exchanger 9, the coolant carrier in the battery liquid-cooling circulation loop is cooled, and at the same time, the battery is refrigerated and the cab is heated, that is, the battery refrigeration mode and the cab heating mode are turned on simultaneously.

[0074] Heat exchange occurs between the liquid-cooled side and the refrigerant side of the first plate heat exchanger 9. Similarly, heat exchange occurs between the liquid-cooled side and the refrigerant side of the second plate heat exchanger 14.

[0075] The motor radiator speeds up the heat exchange with the external environment through the fan, and the out-of-vehicle condenser 3 also speeds up the heat exchange with the external environment through the same fan, that is, the out-of-vehicle condenser 3 and the motor radiator share the fan (radiation fan).

[0076] The utility model can simultaneously meet the vehicle's overall thermal management requirements such as the cab air-conditioning demand, battery cooling demand, and motor cooling demand of pure electric vehicles. Specifically, it uses the waste heat of the motor to heat the cab, thereby improving the heating efficiency, reducing power consumption, increasing the vehicle's cruising range, and solving the problem of high energy consumption when heating the cab in winter in the existing thermal management system of pure electric vehicles.

[0077] The technical solution of the present utility model for the heat pump system of pure electric vehicles mainly includes three parts, specifically including: the cab refrigeration system, the cab heating system, and the battery cooling system. Each system can operate independently, and the cab refrigeration system and the battery cooling system can operate together in pairs, and the cab heating system and the battery cooling system can also operate together in pairs.

[0078] The working modes of the heat pump system include the following 5 types:

[0079] 1) Cab refrigeration mode: The refrigerant circulation loop is composed of a compressor 1, a third solenoid valve 2, an outdoor condenser 3, a first check valve 4, a third electronic expansion valve 5, an in-vehicle evaporator 6, a gas-liquid separator 7 and the corresponding pipeline system. The specific circulation flow path is as Figure 3 shown.

[0080] 2) Battery refrigeration mode: The refrigerant circulation loop is composed of a compressor 1, a third solenoid valve 2, an outdoor condenser 3, a first check valve 4, a second electronic expansion valve 8, the refrigerant side of a first plate heat exchanger 9, a gas-liquid separator 7 and the corresponding pipeline system. The specific circulation flow path is as Figure 4 shown. The present utility model realizes the heat exchange between the battery water path (battery liquid cooling circulation loop) and the refrigerant path where the refrigerant side of the first plate heat exchanger 9 is located through the heat exchange between the refrigerant side and the liquid cooling side of the first plate heat exchanger 9, so as to achieve the purpose of the battery evaporator.

[0081] 3) Cab refrigeration and battery refrigeration mode: The refrigerant circulation loop is composed of two parts: the cab refrigeration mode and the battery refrigeration mode; that is, after sharing the compressor 1, the third solenoid valve 2, the outdoor condenser 3, the first check valve 4 and the corresponding pipeline system, it is divided into two paths. One path is for cab refrigeration, passing through the third electronic expansion valve 5, the in-vehicle evaporator 6 and the corresponding pipeline system; the other path is for battery refrigeration, passing through the second electronic expansion valve 8, the refrigerant side of the first plate heat exchanger 9 and the corresponding pipeline system; the two paths converge at the input side of the gas-liquid separator 7 and then return to the compressor 1 through the corresponding pipeline system.

[0082] 4) Cab heating mode: The refrigerant circulation loop is composed of a compressor 1, a second solenoid valve 11, an in-vehicle condenser 12, a first electronic expansion valve 13, the refrigerant side of a second plate heat exchanger 14, a second check valve 16, a first solenoid valve 17, a gas-liquid separator 7 and the corresponding pipeline system. The specific circulation flow path is as Figure 5 shown. The present utility model realizes the heat exchange between the motor water path (motor liquid cooling circulation loop) and the refrigerant path where the refrigerant side of the second plate heat exchanger 14 is located through the heat exchange between the refrigerant side and the liquid cooling side of the second plate heat exchanger 14, so as to achieve the purpose of the motor evaporator.

[0083] 5) Cab heating and battery cooling mode: The refrigerant circulation loop consists of a compressor 1, a second solenoid valve 11, an in-vehicle condenser 12, a first electronic expansion valve 13, the refrigerant side of a second plate heat exchanger 14, a second check valve 16, a second electronic expansion valve 8, the refrigerant side of a first plate heat exchanger 9, a gas-liquid separator 7, and the corresponding pipeline system. The specific circulation flow path is as Figure 6 shown.

[0084] The pure electric vehicle thermal management system (heat pump system) of the present utility model further includes: a battery liquid cooling circulation system (battery liquid cooling circulation loop), which is composed of a first water pump 10, a battery pack heat exchanger (shown as the battery pack in the figure) for heat exchange with the battery pack, the liquid cooling side of a first plate heat exchanger 9, and the corresponding cooling pipeline system.

[0085] The first plate heat exchanger 9 consists of a refrigerant end (refrigerant side) and a liquid cooling end (liquid cooling side). The refrigerant end of the first plate heat exchanger 9 constitutes a battery evaporator. The liquid cooling end of the first plate heat exchanger 9, a power battery heat exchanger (battery pack heat exchanger) for heat exchange with the power battery, a first water pump 10, and the corresponding pipeline system constitute a battery liquid cooling circulation system. The relatively high-temperature battery cooling antifreeze (cooling medium) in the liquid cooling end of the first plate heat exchanger 9 exchanges heat with the low-temperature refrigerant in the refrigerant end of the first plate heat exchanger 9. By turning on the first water pump 10 for liquid cooling circulation, the purpose of battery cooling is achieved, and thus the battery cooling mode is realized.

[0086] The pure electric vehicle thermal management system of the present utility model further includes a motor liquid cooling circulation system (motor liquid cooling circulation loop), which is composed of the liquid cooling side of a second plate heat exchanger 14, a second water pump 15, a WPTC (water heater) for heating the cooling medium in the motor liquid cooling circulation loop, a motor controller heat exchanger (shown as the motor controller in the figure) for heat exchange with the motor controller, a motor heat exchanger (shown as the motor in the figure) for heat exchange with the motor, and a motor radiator for realizing heat exchange between the motor and the environment, and the corresponding cooling pipeline system.

[0087] The second plate heat exchanger 14 consists of a refrigerant end (refrigerant side) and a liquid cooling end (liquid cooling side). The refrigerant end of the second plate heat exchanger 14 constitutes a motor evaporator. The liquid cooling end of the second plate heat exchanger 14, a motor heat exchanger for heat exchange with the motor, a motor controller heat exchanger for heat exchange with the motor controller, a second water pump 15, a water heater, and a motor radiator, and the corresponding pipeline system constitute a motor liquid cooling circulation system. The relatively high-temperature motor cooling antifreeze (cooling medium) in the liquid cooling end of the second plate heat exchanger 14 exchanges heat with the low-temperature refrigerant in the refrigerant end of the second plate heat exchanger 14. By turning on the second water pump 15 for liquid cooling circulation, the purpose of motor cooling is achieved, and thus the cab heating mode is realized.

[0088] Specifically, when the ambient temperature is lower than a certain value, there is no demand for cab air-conditioning refrigeration, and the battery needs to be cooled. At this time, the refrigerant circulation system does not work, that is, the compressor does not work. By turning on the first water pump 10 in the water circulation mode only, the purpose of cooling the battery is achieved, and the energy consumption required by the thermal management system is reduced. The battery cooling of the present invention uses the self-circulation mode of the water pump to cool the battery under low-temperature conditions, which not only improves the reliability of the system operation but also reduces the power consumption of the whole vehicle.

[0089] When there is no demand for cab heating and the motor needs to be cooled, the refrigerant circulation system does not work at this time. Instead, by turning on the second water pump 15 and the motor radiator system, the motor is naturally cooled to achieve the purpose of cooling the motor and reducing the energy consumption required by the thermal management system.

[0090] The thermal management system of the present invention is a more efficient and energy-saving vehicle thermal management system in the form of a heat pump. Among them, the battery cooling and the refrigeration and heating of the cab are all realized through the heat exchange of the secondary refrigerant. The battery cooling of the present invention and the refrigeration and heating of the cab are the same set of compressor operation systems, canceling the heating mode of the high-power air heater PTC in the current mainstream models, greatly reducing the power consumption of the whole vehicle in winter and improving the vehicle's cruising range.

[0091] The compressor and the cooling fan adopted by the present invention all adopt variable frequency control to meet the requirements of different cooling capacities and air volumes under different operating conditions, reduce the start-stop times of the compressor, and improve the energy utilization efficiency. Compared with the existing thermal management systems of pure electric vehicles using battery liquid cooling, cab air-conditioning integrated thermal management, and battery air cooling and independent air-conditioning, the vehicle thermal management system provided by the present invention can simultaneously meet the vehicle thermal management requirements such as the cab air-conditioning demand, battery cooling demand, and motor cooling demand of pure electric vehicles, further improving the integration of the vehicle thermal management system, enhancing the heating efficiency of the air conditioner in winter, reducing the power consumption of the whole vehicle, improving the vehicle's cruising range, and reducing the operating cost of customers.

Claims

1. A heat pump system for a pure electric vehicle, characterized in that: A compressor is included, wherein a refrigerant section inside the vehicle, a refrigerant section for the motor and a refrigerant section for the battery are sequentially connected in series on a pipeline between an output side of the compressor and an input side thereof, wherein the refrigerant section inside the vehicle and the refrigerant section for the motor connected in series are also connected in parallel with a refrigerant branch outside the vehicle, and the refrigerant section for the battery is also connected in parallel with an in-vehicle refrigeration branch and a bypass branch, wherein the in-vehicle refrigeration branch and the bypass branch are connected in parallel; The bypass branch includes a pipeline connected in series with a first valve; The in-vehicle refrigerant section includes a second valve connected in series and an in-vehicle condenser for exchanging heat with the in-cab environment; The motor refrigerant section includes a first expansion valve connected in series and a motor assembly heat exchanger for exchanging heat with the motor liquid cooling circulation loop, and the first expansion valve is arranged on a pipeline close to the input side of the motor assembly heat exchanger; The battery refrigerant section includes a second expansion valve connected in series and a battery heat exchanger for exchanging heat with a battery liquid cooling circulation loop, and the second expansion valve is arranged on a pipeline close to the input side of the battery heat exchanger; The external refrigerant branch includes a third valve connected in series and an external condenser for exchanging heat with the external environment; The in-vehicle cooling branch includes a third expansion valve connected in series and an in-vehicle evaporator for cooling the interior environment of the cab, wherein the third expansion valve is arranged on a pipeline close to an input side of the in-vehicle evaporator.

2. The heat pump system for a pure electric vehicle according to claim 1, characterized in that: The first expansion valve, the second expansion valve and the third expansion valve are all electronic expansion valves.

3. The heat pump system for a pure electric vehicle according to claim 1, characterized in that: The motor liquid cooling circulation loop includes a circulating water pump connected in series, a motor controller heat exchanger for heat exchange with the motor controller, a motor heat exchanger for heat exchange with the motor, a motor radiator for heat exchange with the environment, and the motor assembly heat exchanger. The motor radiator accelerates heat exchange with the environment through a fan.

4. The heat pump system for a pure electric vehicle according to claim 3, characterized in that: The external condenser also accelerates heat exchange with the environment through the fan.

5. The heat pump system for a pure electric vehicle according to claim 4, characterized in that: The motor radiator and the external condenser are arranged in sequence along the air flow direction of the fan.

6. The heat pump system for a pure electric vehicle according to claim 3, characterized in that: The motor liquid cooling circulation loop is also connected in series with a heater for heating the coolant in the motor liquid cooling circulation loop.

7. The heat pump system for a pure electric vehicle according to claim 1, characterized in that: Valves for preventing backflow are respectively provided on the pipeline between the connecting point between the output side of the external condenser and the output side of the motor assembly heat exchanger and the output side of the external condenser, and on the pipeline between the connecting point between the output side of the external condenser and the output side of the motor assembly heat exchanger and the output side of the motor assembly heat exchanger.

8. The heat pump system for a pure electric vehicle according to claim 7, characterized in that: A valve for preventing backflow is arranged near the connecting point.

9. The heat pump system for a pure electric vehicle according to claim 7, characterized in that: A check valve is used to prevent backflow.

10. The heat pump system for a pure electric vehicle according to claim 7, characterized in that: The valve used to prevent backflow is a solenoid valve.

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