Whole-vehicle thermal management integrated system of pure electric vehicle based on heat pump and control method of whole-vehicle thermal management integrated system

Abstract

The invention relates to the technical field of heat management, in particular to a heat pump-based whole-vehicle heat management integrated system for a pure electric vehicle and a control method, which comprises a cooling liquid loop, a water pump I, a heater, an expansion water tank I, a motor, an electric controller, a refrigerant loop I, a refrigerant loop II, an electronic expansion valve III, a liquid cooling plate, a battery pack and an electromagnetic valve IV, two parts are integrated and optimized into one part, the number of parts is effectively reduced, the production and manufacturing cost of the whole vehicle is greatly reduced, the weight of the vehicle body is reduced, the internal space of a cabin is saved, meanwhile, a thermal system of the whole vehicle is integrated, energy is absorbed from the environment and waste heat, and the endurance mileage can be greatly increased; therefore, the problem that an existing new energy commercial vehicle heat management system occupies a large space is solved.

Description

Technical Field

[0001] The present invention relates to the field of thermal management technology, and in particular to a heat pump-based integrated thermal management system and a control method for a pure electric vehicle. Background Art

[0002] Integrated thermal management for new energy commercial vehicles is a comprehensive vehicle thermal management strategy that integrates various heat-generating systems in the vehicle, such as the battery system, motor and electronic control system, and cab air conditioning system, to perform unified temperature control and heat allocation. For new energy commercial vehicles, this management method can, on the one hand, ensure that key vehicle components operate in a suitable temperature environment, thereby improving the working efficiency and service life of the components. On the other hand, reasonable integrated thermal management helps improve the overall energy efficiency of the vehicle, reduce energy loss through waste heat recovery, and increase the vehicle's range.

[0003] At present, the thermal management system of new energy commercial vehicles has the problem of low integration. Some thermal management systems of new energy commercial vehicles still use independent cooling systems, and the motor and electronic control, battery, and cockpit use independent circuits for thermal management control, which makes the system occupy a large space, the vehicle weight is heavy, and the use and maintenance costs are high. At the same time, compared with the integrated thermal management system, the thermal control efficiency of the separate cooling circuit is low and the energy consumption is high. Existing integrated thermal management systems have problems such as duplication of functional parts and effects. Often, the functional properties of several components are the same, which leads to low overall heat exchange efficiency of the system. Summary of the invention

[0004] The purpose of the present invention is to provide a heat pump-based pure electric vehicle thermal management integrated system and control method, aiming to solve the problem of large space occupation of existing new energy commercial vehicle thermal management systems.

[0005] To achieve the above-mentioned purpose, in a first aspect, the present invention provides a thermal management integrated system for a pure electric vehicle based on a heat pump, comprising a coolant circuit, a water pump 1, a heater, an expansion water tank 1, a motor, an electronic control, a refrigerant circuit 1, a refrigerant circuit 2, an electronic expansion valve 3, a liquid cooling plate, a battery pack and a solenoid valve 4;

[0006] The coolant circuit, the water pump 1, the heater, the expansion water tank 1, the motor and the electronic control are connected in sequence; the refrigerant circuit 1 and the refrigerant circuit 2 are respectively connected to the coolant circuit; the electronic expansion valve 3 is connected to the refrigerant circuit 1, the refrigerant circuit and the coolant circuit, the liquid cooling plate is connected to the electronic expansion valve 3 and to the battery pack, and the solenoid valve 4 is connected to the liquid cooling plate and to the refrigerant circuit 1.

[0007] Among them, the coolant circuit includes a three-way valve, a radiator, a fan, a second water pump, a second expansion water tank and a water-cooled condenser. The three-way valve is connected to the first water pump, the radiator, the second water pump, the second expansion water tank and the water-cooled condenser are connected in sequence, the fan is connected to the radiator, and the water-cooled condenser is connected to the three-way valve.

[0008] Among them, the refrigerant circuit 1 includes an electronic expansion valve 1, an indoor evaporator, a gas-liquid separator, a compressor and a solenoid valve 1. The electronic expansion valve 1 is connected to the water-cooled condenser. The electronic expansion valve 1, the indoor evaporator, the gas-liquid separator, the compressor and the solenoid valve 1 are connected in sequence. The solenoid valve 1 is connected to the water-cooled condenser.

[0009] Among them, the refrigerant circuit 2 includes electronic expansion valve 2, indoor condenser, solenoid valve 2 and solenoid valve 3; the electronic expansion valve 2 is connected to the water-cooled condenser, the electronic expansion valve 2, the indoor condenser and the solenoid valve 3 are connected in sequence, the solenoid valve 2 is connected to the gas-liquid separator and to the water-cooled condenser.

[0010] In a second aspect, a heat pump-based integrated control method for thermal management of a pure electric vehicle is used in the heat pump-based integrated control system for thermal management of a pure electric vehicle described in the first aspect, and includes the following steps:

[0011] In cooling mode, the heat of high-temperature and high-pressure refrigerant in refrigerant circuit 1 is transferred to the coolant circuit through the water-cooled condenser, and then the temperature in the coolant is discharged to the outside through the radiator;

[0012] In heating mode, when the refrigerant pressure and temperature at the compressor inlet are insufficient, the fan is turned on to absorb heat from the external environment through the radiator, increase the coolant temperature, and then transfer the heat to the refrigerant circuit 2 through the water-cooled condenser to increase the refrigerant pressure and temperature at the compressor inlet.

[0013] The present invention is a heat pump-based integrated system for thermal management of a pure electric vehicle, wherein the water pump 1 is used to realize the circulation of the coolant, the heater is used for auxiliary heating, the expansion water tank 1 is used to replenish the coolant, the motor and the electronic control generate a large amount of heat when working, the refrigerant circuit 1 is used for cooling mode, the refrigerant circuit 2 is used for heating mode, the electronic expansion valve 3 is used for opening adjustment to control the refrigerant flow, the liquid cooling plate is used to cool the battery pack, and the solenoid valve 4 is used for switching between different circuits. In the cooling mode, the refrigerant circuit 1 exchanges heat between the high-temperature and high-pressure refrigerant and the outside air, and discharges the heat of the high-temperature refrigerant to the outside; in the heating mode, the refrigerant circuit 2 increases the temperature of the coolant and the coolant circuit absorbs heat and heats up. The present invention integrates and optimizes two components into one, effectively reduces the number of parts, greatly reduces the production and manufacturing cost of the whole vehicle, reduces the weight of the vehicle body, saves the internal space of the cabin, and integrates the thermal system of the whole vehicle, develops thermal management from the perspective of the whole vehicle energy management, and absorbs energy from the environment and waste heat as much as possible, which can greatly increase the cruising range, thereby solving the problem of large space occupation of the existing thermal management system of new energy commercial vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 It is a schematic diagram of a heat pump-based integrated thermal management system for a pure electric vehicle provided by the present invention.

[0016] Figure 2 It is a schematic diagram of the motor electronic control heat dissipation mode.

[0017] Figure 3 It is a schematic diagram of single cab cooling.

[0018] Figure 4 It is a schematic diagram of single battery cooling mode.

[0019] Figure 5 This is a schematic diagram of the cab & battery cooling mode.

[0020] Figure 6 It is a schematic diagram of the single cab heating (PTC+heat pump) mode.

[0021] Figure 7 It is a schematic diagram of the single cab heating (heat pump) mode.

[0022] Figure 8It is a schematic diagram of the single cab heating (heat pump + waste heat recovery) mode.

[0023] Fig. 9 It is a schematic diagram of the single cab heating (heat pump + cooling) mode.

[0024] Fig.10 This is a schematic diagram of the single-battery heating (heat pump + PTC) mode.

[0025] Fig.11 It is a schematic diagram of the single battery heating (heat pump) mode.

[0026] Fig.12 This is a schematic diagram of the single-battery heating (heat pump + motor waste heat) mode.

[0027] Fig.13 This is a schematic diagram of the single-battery heating (heat pump + heat dissipation) mode.

[0028] Fig.14 This is a schematic diagram of the cab & battery heating (heat pump + PTC) mode.

[0029] Fig.15 This is a schematic diagram of the cab & battery heating (heat pump) mode.

[0030] Fig.16 This is a schematic diagram of the cab & battery heating (heat pump + motor waste heat) mode.

[0031] Fig.17 This is a schematic diagram of the cab & battery heating (motor waste heat + heat dissipation).

[0032] Fig.18 It is a flow chart of the integrated control method for thermal management of a pure electric vehicle based on a heat pump.

[0033] In the figure: 1-water pump 1, 2-heater, 3-expansion water tank 1, 4-motor, 5-electronic control, 6-electronic expansion valve 3, 7-liquid cooling plate, 8-battery pack, 9-solenoid valve 4, 10-three-way valve, 11-radiator, 12-fan, 13-water pump 2, 14-expansion water tank 2, 15-water-cooled condenser, 16-electronic expansion valve 1, 17-indoor evaporator, 18-gas-liquid separator, 19-compressor, 20-solenoid valve 1, 21-electronic expansion valve 2, 22-indoor condenser, 23-solenoid valve 2, 24-solenoid valve 3. DETAILED DESCRIPTION

[0034] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0035] See also Figures 1 to 17 In the first aspect, the present invention provides a heat pump-based integrated thermal management system for a pure electric vehicle, including a coolant circuit, a water pump 1, a heater 2, an expansion water tank 3, a motor 4, an electronic control 5, a refrigerant circuit 1, a refrigerant circuit 2, an electronic expansion valve 3 6, a liquid cooling plate 7, a battery pack 8 and a solenoid valve 4 9;

[0036] The coolant circuit, the water pump 1, the heater 2, the expansion water tank 3, the motor 4 and the electronic control 5 are connected in sequence; the refrigerant circuit 1 and the refrigerant circuit 2 are respectively connected to the coolant circuit; the electronic expansion valve 3 6 is connected to the refrigerant circuit 1, the refrigerant circuit and the coolant circuit, the liquid cooling plate 7 is connected to the electronic expansion valve 3 6 and to the battery pack 8, and the solenoid valve 4 9 is connected to the liquid cooling plate 7 and to the refrigerant circuit 1.

[0037] In this embodiment, the water pump 1 is used to realize the circulation of the coolant, the heater 2 is used for auxiliary heating, the expansion water tank 3 is used to replenish the coolant, the motor 4 and the electronic control 5 generate a lot of heat when working, the refrigerant circuit 1 is used for cooling mode, the refrigerant circuit 2 is used for heating mode, the electronic expansion valve 3 6 is used for opening adjustment to control the refrigerant flow, the liquid cooling plate 7 is used to cool the battery pack 8, and the solenoid valve 4 9 is used for switching between different circuits. In the cooling mode, the refrigerant circuit 1 exchanges heat between the high-temperature and high-pressure refrigerant and the outside air, and discharges the heat of the high-temperature refrigerant to the outside; in the heating mode, the refrigerant circuit 2 increases the temperature of the coolant and the coolant circuit absorbs heat and heats up. The present invention integrates and optimizes two components into one, effectively reduces the number of parts, greatly reduces the production and manufacturing cost of the whole vehicle, reduces the weight of the vehicle body, saves the internal space of the cabin, and integrates the thermal system of the whole vehicle, and develops thermal management from the perspective of the whole vehicle energy management, and absorbs energy from the environment and waste heat as much as possible, which can greatly increase the cruising range, thereby solving the problem of large space occupation of the existing thermal management system of new energy commercial vehicles.

[0038] Furthermore, the coolant circuit includes a three-way valve 10, a radiator 11, a fan 12, a water pump 13, an expansion water tank 14 and a water-cooled condenser 15. The three-way valve 10 is connected to the water pump 1, the radiator 11, the water pump 13, the expansion water tank 14 and the water-cooled condenser 15 are connected in sequence, the fan 12 is connected to the radiator 11, and the water-cooled condenser 15 is connected to the three-way valve 10.

[0039] In this embodiment, the three-way valve 10 is used to switch the LCC circuit and the outdoor radiator 11 circuit to realize the switching of the heat dissipation of the drive motor 4, the waste heat recovery of the motor 4 and the refrigerant condensation function. The radiator 11 is used to dissipate heat, and the fan 12 cools the refrigerant and the coolant by forcing air to flow through the surface of the front radiator 11. The water pump 13 is used to circulate the coolant circuit, and the expansion water tank 14 is used to store the coolant. The water-cooled condenser 15 is used to absorb the high-temperature coolant in the water circuit, dissipate heat and recover the waste heat of the motor 4 for use.

[0040] Furthermore, the refrigerant circuit 1 includes an electronic expansion valve 16, an indoor evaporator 17, a gas-liquid separator 18, a compressor 19 and a solenoid valve 20, the electronic expansion valve 16 is connected to the water-cooled condenser 15, the electronic expansion valve 16, the indoor evaporator 17, the gas-liquid separator 18, the compressor 19 and the solenoid valve 20 are connected in sequence, and the solenoid valve 20 is connected to the water-cooled condenser 15.

[0041] In this embodiment, the electronic expansion valve 16 controls the refrigerant flow rate of the refrigeration device by adjusting the opening degree. The refrigerant expands and vaporizes in the indoor evaporator 17 to absorb heat, thereby cooling the cockpit intake air. The gas-liquid separator 18 is used to absorb the liquid in the refrigerant to prevent the liquid from entering the compressor 19. The compressor 19 compresses the low-temperature and low-pressure gaseous refrigerant into a high-temperature and high-pressure gaseous refrigerant. The solenoid valve 20 realizes the switching of different circuits of the heat pump air conditioner to achieve the refrigeration function.

[0042] Furthermore, the refrigerant circuit 2 includes an electronic expansion valve 21, an indoor condenser 22, a solenoid valve 23 and a solenoid valve 3 24; the electronic expansion valve 21 is connected to the water-cooled condenser 15, the electronic expansion valve 21, the indoor condenser 22 and the solenoid valve 3 24 are connected in sequence, the solenoid valve 23 is connected to the gas-liquid separator 18, and is connected to the water-cooled condenser 15.

[0043] In this embodiment, the electronic expansion valve 21 controls the flow rate of the refrigerant in the refrigeration device by adjusting the opening. The refrigerant in the indoor condenser 22 condenses and liquefies in the indoor condenser 22 to release heat, thereby heating the intake air in the low cab. The solenoid valve 23 and the solenoid valve 3 24 switch between different circuits of the heat pump air conditioner to achieve the heating function.

[0044] Figure 2 Motor electronic control cooling mode:

[0045] The cab has a cooling demand, but the battery has no cooling or heating demand. The high-temperature and high-pressure refrigerant releases heat through the outdoor radiator, changes to a low-temperature and low-pressure state through the electronic expansion valve EXV1, and absorbs heat through the indoor evaporator to achieve a cooling effect in the cab. Working conditions: The air conditioning refrigeration switch is turned on, and the knob is turned to the cooling position, and the maximum battery temperature is ≤35°C. Execution action: SOV1 is turned on, SOV2, 3, and 4 are closed, the opening of the electronic expansion valve EXV1 is adjusted according to the subcooling of the refrigerant at the evaporative condenser, EXV2 and 3 are closed, the fan and compressor are turned on, water pump 2 is turned on, and channels 1 and 2 of the three-way valve are connected.

[0046] Figure 3 Single Cab Cooling:

[0047] When there is no cooling demand in the cab and the battery temperature is too high and needs to be cooled, the high-temperature and high-pressure refrigerant releases heat through the outdoor radiator, passes through the electronic expansion valve EXV3 and becomes a low-temperature and low-pressure state, and passes through the liquid cooling plate to cool the battery pack. Working conditions: The air conditioning refrigeration switch is turned off, and the knob is turned to the cooling gear, and the maximum battery temperature is greater than 35°C. Execution action: SOV1 and 4 are turned on, SOV2 and 3 are turned off, the opening of the electronic expansion valve EXV3 is adjusted according to the supercooling of the refrigerant at the liquid cooling plate, EXV1 and 2 are turned off, the fan and compressor are turned on, water pump 2 is turned on, and channels 1 and 2 of the three-way valve are connected.

[0048] Figure 4 Single battery cooling mode:

[0049] When the cab and the battery need cooling at the same time, the high-temperature and high-pressure refrigerant releases heat through the outdoor radiator, changes to a low-temperature and low-pressure state through the electronic expansion valves EXV1 and 3, and passes through the liquid cooling plate and the indoor evaporator respectively to cool the cab and the battery pack. Working conditions: The air conditioning refrigeration switch is turned on, and the knob is turned to the cooling position, and the maximum battery temperature is greater than 35°C. Execution action: SOV1 and 4 are turned on, SOV2 and 3 are turned off, the opening of the electronic expansion valve EXV3 is adjusted according to the refrigerant supercooling at the liquid cooling plate, the opening of the electronic expansion valve EXV1 is adjusted according to the refrigerant supercooling at the evaporative condenser, EXV2 is turned off, the fan and compressor are turned on, water pump 2 is turned on, and channels 1 and 2 of the three-way valve are connected.

[0050] Figure 5 Cab & Battery Cooling Mode:

[0051] The cab has a heating demand, but the battery has no cooling or heating demand. When the ambient temperature is too low, the PTC is turned on to heat the coolant. The high-temperature refrigerant heats the cab through the indoor condenser. After the refrigerant passes through the expansion valve, it absorbs heat from the heated coolant through the LCC to complete the heating cycle. Working conditions: When the water temperature is less than 0°C and the ambient temperature is less than -10°C. Execution action: SOV2 and 3 are turned on, SOV1 and 4 are closed, the opening of the electronic expansion valve EXV2 is adjusted according to the superheat of the refrigerant at the indoor condenser, EXV1 and 3 are closed, the three-way valve 2 and 3 channels are connected, the compressor is turned on, and as soon as the water pump is turned on, the PTC is turned on to heat the coolant.

[0052] Figure 6 Single cab heating (PTC+heat pump) mode:

[0053] The cab needs to be heated, but the battery does not need to be cooled or heated. When the temperature difference between the water temperature and the environment is insufficient, the temperature difference between the refrigerant and the water temperature is very small after the refrigerant absorbs heat from the environment through the outdoor radiator. Therefore, the water pump is turned off and only heat is absorbed from the outdoor environment. Working conditions: 0<water temperature<25℃ and water temperature-ambient temperature<5℃. Execution action: SOV2 and 3 are opened, SOV1 and 4 are closed, the opening of the electronic expansion valve EXV2 is adjusted according to the superheat of the refrigerant at the indoor condenser, EXV1 and 3 are closed, the fan and compressor are turned on, water pump 2 is turned on, and channels 1 and 2 of the three-way valve are connected.

[0054] Figure 7 Single cab heating (heat pump) mode:

[0055] When the air conditioner is turned on for heating, the battery has no cooling or heating demand, the ambient temperature is too low, or the water temperature is high enough, turn off the fan, connect the motor coolant circuit, and the refrigerant no longer absorbs heat from the outside, but absorbs heat from the coolant when passing through the LCC. Working conditions: When the water temperature is ≥25℃. Execution action: SOV2 and 3 are turned on, SOV1 and 4 are closed, the opening of the electronic expansion valve EXV2 is adjusted according to the superheat of the refrigerant at the indoor condenser, EXV1 and 3 are closed, and the three-way valve 2 and 3 channels are connected. The water pump 1 and the compressor are turned on.

[0056] Figure 8 Single cab heating (heat pump + waste heat recovery) mode:

[0057] The air conditioner is turned on for heating, and the battery has no cooling or heating demand, but when the water temperature is too high, the fan is turned on, the three-way valve is fully opened, part of the coolant is diverted to the radiator for heat dissipation, and the other part transfers heat to the refrigerant through the LCC. Working conditions: 0<water temperature<25℃ and water temperature-ambient temperature≥5℃ and ambient temperature>-10℃. Execution action: SOV2, 3 are turned on, SOV1, 4 are closed, the opening of the electronic expansion valve EXV2 is adjusted according to the superheat of the refrigerant at the indoor condenser, EXV1, 3 are closed, and the 1, 2, 3 channels of the three-way valve are connected, and the water pump 1, fan, and compressor are turned on.

[0058] Fig. 9 Single cab heating (heat pump + cooling) mode:

[0059] There is no demand for cooling or heating in the cab, but the battery needs heating. When the ambient temperature is too low and the motor water temperature is insufficient, the efficiency of absorbing heat from the environment is too slow. Turn on PTC to provide heat to the coolant, and the refrigerant absorbs heat from the coolant in the LCC to supply the battery pack. Working conditions: -5≤ water temperature < 0℃ and ambient temperature < -10℃. Execution: SOV2 and 3 are turned on, SOV1 and 4 are closed, the opening of the electronic expansion valve EXV3 is adjusted according to the superheat of the refrigerant at the liquid cooling plate, EXV1 and 2 are closed, and the three-way valve 2 and 3 channels are connected. PTC, water pump 1, and compressor are turned on.

[0060] Fig.10 Single battery heating (heat pump + PTC) mode:

[0061] There is no need for cooling or heating in the cab, but the battery needs heating. When the temperature difference between the water temperature and the ambient temperature is insufficient, the compressor, fan and water pump 2 are turned on, and the refrigerant absorbs heat from the external environment. Working conditions: 0≤water temperature<25℃ and water temperature-ambient temperature<5℃. Execution action: SOV2 and 3 are turned on, SOV1 and 4 are turned off, the opening of the electronic expansion valve EXV3 is adjusted according to the superheat of the refrigerant at the liquid cooling plate, EXV1 and 2 are turned off, water pump 2, fan and compressor are turned on, and channels 1 and 2 of the three-way valve are connected.

[0062] Fig.11 Single battery heating (heat pump) mode:

[0063] There is no need for cooling or heating in the cab, but the battery needs heating. When the ambient temperature is too low, turn off the fan. After the refrigerant releases heat through the liquid cooling plate, it absorbs the heat in the motor circuit coolant through the LCC. Working conditions: 0 < water temperature < 25 °C and water temperature - ambient temperature ≥ 5 °C and ambient temperature < -10 °C. Execution: SOV2 and 3 are opened, SOV1 and 4 are closed, the opening of the electronic expansion valve EXV3 is adjusted according to the superheat of the refrigerant at the liquid cooling plate, EXV1 and 2 are closed, the three-way valve 2 and 3 channels are connected, and the water pump 1 and the compressor are turned on.

[0064] Fig.12 Single battery heating (heat pump + motor waste heat) mode:

[0065] The battery pack needs to be heated, and the cab has no cooling or heating requirements. However, when the water temperature is too high, the fan is turned on, the three-way valve is fully opened, part of the coolant is diverted to the radiator for heat dissipation, and the other part transfers heat to the refrigerant through the LCC. Working conditions: 0<water temperature<25℃ and water temperature-ambient temperature≥5℃ and ambient temperature>-10℃. Execution action: SOV2, 3 are opened, SOV1, 4 are closed, the opening of the electronic expansion valve EXV2 is adjusted according to the superheat of the refrigerant at the indoor condenser, EXV1, 3 are closed, and the 1, 2, 3 channels of the three-way valve are connected, and the water pump 1, fan, and compressor are turned on.

[0066] Fig.13 Single battery heating (heat pump + cooling) mode:

[0067] When the cab needs to be heated, the battery needs to be heated, or the ambient temperature is too low and the heating efficiency is too slow by absorbing heat from the environment, turn off the fan, turn on W-PTC to provide heat to the system, and the refrigerant absorbs heat from the coolant through LCC. Working conditions: When the water temperature is less than 0°C and the ambient temperature is less than -10°C. Execution: SOV2 and 3 are turned on, SOV1 and 4 are turned off, the opening of the electronic expansion valve EXV3 is adjusted according to the superheat of the refrigerant at the liquid cooling plate, and the opening of the electronic expansion valve EXV2 is adjusted according to the superheat of the refrigerant at the indoor condenser. EXV1 is closed, and the three-way valve 2 and 3 channels are connected. The water pump 1, PTC, and compressor are turned on.

[0068] Fig.14 Cab & battery heating (heat pump + PTC) mode:

[0069] When the cab needs to be heated, the battery needs to be heated, and the ambient temperature is moderate, turn on the fan, and the refrigerant first absorbs heat from the environment through the outdoor heat exchanger, then absorbs heat from the coolant through the LCC, and then supplies heat to the cab and battery at the same time. Working conditions: 0≤water temperature<25℃ and motor water temperature-battery water temperature<5℃ and ambient temperature>-10℃. Execution action: SOV2, 3 are turned on, SOV1, 4 are closed, the opening of the electronic expansion valve EXV3 is adjusted according to the superheat of the refrigerant at the liquid cooling plate, the opening of the electronic expansion valve EXV2 is adjusted according to the superheat of the refrigerant at the indoor condenser, EXV1 is closed, and the 1 and 2 channels of the three-way valve are connected, and the water pump 2, fan, and compressor are turned on.

[0070] Fig.15 Cab & battery heating (heat pump) mode:

[0071] The cab needs to be heated, the battery needs to be heated, and when the ambient temperature is too low, turn off the fan. After the refrigerant releases heat through the liquid cooling plate, it absorbs the heat in the motor circuit coolant through the LCC. Working conditions: 0 < water temperature < 25 ° C and water temperature - ambient temperature ≥ 5 ° C and ambient temperature < -10 ° C. Execution action: SOV2, 3 open, SOV1, 4 closed, the opening of the electronic expansion valve EXV3 is adjusted according to the superheat of the refrigerant at the liquid cooling plate, the opening of the electronic expansion valve EXV2 is adjusted according to the superheat of the refrigerant at the indoor condenser, EXV1 is closed, the three-way valve 2, 3 channels are connected, and the water pump 1 and the compressor are turned on.

[0072] Fig.16 Cab & battery heating (heat pump + motor waste heat) mode:

[0073] There is a need for heating in the cab and the battery. When the coolant temperature is too high, the three-way valve is fully opened, part of the coolant is diverted to the radiator to release heat, and part of the coolant passes through the LCC to transfer heat to the refrigerant, and then supplies the indoor condenser and liquid cooling plate to heat the interior and battery pack. Working conditions: When the water temperature is ≥35°C. Execution action: SOV2 and 3 are opened, SOV1 and 4 are closed, the opening of the electronic expansion valve EXV3 is adjusted according to the superheat of the refrigerant at the liquid cooling plate, and the opening of the electronic expansion valve EXV2 is adjusted according to the superheat of the refrigerant at the indoor condenser. EXV1 is closed, and the 1, 2, and 3 channels of the three-way valve are connected, and the water pump 1, fan, and compressor are turned on.

[0074] Fig.17 Cab & battery heating (motor waste heat + heat dissipation):

[0075] Dehumidification mode When the dehumidification switch is turned on, the indoor evaporator and indoor condenser are turned on at the same time. The air with high humidity is first cooled by the evaporator, and the water is condensed and discharged, and then passes through the indoor condenser to absorb heat and heat up to become dry air. Working conditions: When the dehumidification switch is turned on.

[0076] Execution action: SOV3 is opened, SOV1, 2, and 4 are closed, the opening of the electronic expansion valve EXV1 is adjusted according to the superheat of the refrigerant at the indoor evaporator, the opening of the electronic expansion valve EXV2 is adjusted according to the superheat of the refrigerant at the indoor condenser, EXV1 is closed, and the compressor is started.

[0077] See also Fig.18 In the second aspect, a heat pump-based integrated control method for thermal management of a pure electric vehicle is used in the heat pump-based integrated thermal management system of a pure electric vehicle described in the first aspect, and comprises the following steps:

[0078] In cooling mode, the heat of high-temperature and high-pressure refrigerant in refrigerant circuit 1 is transferred to the coolant circuit through the water-cooled condenser, and then the temperature in the coolant is discharged to the outside through the radiator;

[0079] Specifically, when the high-temperature and high-pressure refrigerant is discharged from the compressor, it exchanges heat with the motor electronic control circuit through the water-cooled condenser LCC. At this time, the three-way valve in the coolant circuit is connected to ports 1 and 2. At this time, the coolant circuit temperature is significantly lower than the refrigerant temperature at the compressor outlet, so the heat flows from the refrigerant circuit to the coolant circuit. Water pump 2 is turned on, and the motor electronic control circuit coolant begins to self-circulate through the radiator, discharging the heat exchanged by the refrigerant circuit to the outside through the radiator, which plays a role in cooling the refrigerant, thereby achieving the purpose of using the outdoor radiator to replace the outdoor condenser.

[0080] In heating mode, when the refrigerant pressure and temperature at the compressor inlet are insufficient, S2 turns on the fan, absorbs heat from the external environment through the radiator, increases the coolant temperature, and then transfers the heat to the refrigerant circuit 2 through the water-cooled condenser, thereby increasing the refrigerant pressure and temperature at the compressor inlet.

[0081] Specifically, after the high-temperature and high-pressure refrigerant is discharged from the compressor, it releases heat through the indoor condenser via the solenoid valve SOV3, and then becomes a low-temperature and low-pressure refrigerant through the throttling of the electronic expansion valve. At this time, the refrigerant entering the compressor inlet is too low in temperature and pressure, so it is difficult to start the compressor, so it is necessary to increase the refrigerant pressure by heating. The fan is turned on to absorb heat from the external environment, and the 1 and 2 of the three-way valve of the coolant circuit are connected to the small cycle to increase the coolant temperature. When the low-temperature refrigerant passes through the water-cooled condenser LCC, the temperature of the coolant circuit is higher than the refrigerant temperature, and the refrigerant absorbs heat from the coolant circuit and heats up. Due to the nature of the refrigerant itself, the pressure increases after the temperature rises. At this time, the refrigerant pressure at the compressor inlet gradually increases to the minimum starting pressure of the compressor, ensuring the normal start-up of the compressor. In this way, the purpose of using the outdoor radiator to replace the outdoor condenser is achieved.

[0082] The above disclosure is only a preferred embodiment of the thermal management integrated system and control method of a pure electric vehicle based on a heat pump of the present invention. Of course, this cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiments and equivalent changes made in accordance with the claims of the present invention still fall within the scope of the invention.

Claims

1. A heat pump-based integrated thermal management system for pure electric vehicles, characterized by: It includes a coolant circuit, a water pump 1, a heater, an expansion water tank 1, a motor, an electronic control, a refrigerant circuit 1, a refrigerant circuit 2, an electronic expansion valve 3, a liquid cooling plate, a battery pack and a solenoid valve 4; The coolant circuit, the water pump 1, the heater, the expansion water tank 1, the motor and the electronic control are connected in sequence; the refrigerant circuit 1 and the refrigerant circuit 2 are respectively connected to the coolant circuit; the electronic expansion valve 3 is connected to the refrigerant circuit 1, the refrigerant circuit and the coolant circuit, the liquid cooling plate is connected to the electronic expansion valve 3 and to the battery pack, and the solenoid valve 4 is connected to the liquid cooling plate and to the refrigerant circuit 1.

2. The heat pump-based integrated thermal management system for a pure electric vehicle as claimed in claim 1, characterized in that: The coolant circuit includes a three-way valve, a radiator, a fan, a second water pump, a second expansion water tank and a water-cooled condenser. The three-way valve is connected to the first water pump, the radiator, the second water pump, the second expansion water tank and the water-cooled condenser are connected in sequence, the fan is connected to the radiator, and the water-cooled condenser is connected to the three-way valve.

3. The heat pump-based integrated thermal management system for a pure electric vehicle as claimed in claim 2, characterized in that: The refrigerant circuit 1 includes an electronic expansion valve 1, an indoor evaporator, a gas-liquid separator, a compressor and a solenoid valve 1. The electronic expansion valve 1 is connected to the water-cooled condenser. The electronic expansion valve 1, the indoor evaporator, the gas-liquid separator, the compressor and the solenoid valve 1 are connected in sequence. The solenoid valve 1 is connected to the water-cooled condenser.

4. The heat pump-based integrated thermal management system for a pure electric vehicle as claimed in claim 3, characterized in that: The refrigerant circuit 2 includes an electronic expansion valve 2, an indoor condenser, a solenoid valve 2 and a solenoid valve 3; the electronic expansion valve 2 is connected to the water-cooled condenser, the electronic expansion valve 2, the indoor condenser and the solenoid valve 3 are connected in sequence, the solenoid valve 2 is connected to the gas-liquid separator and to the water-cooled condenser.

5. A heat pump-based integrated control method for thermal management of a pure electric vehicle, used in a heat pump-based integrated thermal management system for a pure electric vehicle according to any one of claims 1 to 4, characterized in that: The following steps are involved: In cooling mode, the heat of high-temperature and high-pressure refrigerant in refrigerant circuit 1 is transferred to the coolant circuit through the water-cooled condenser, and then the temperature in the coolant is discharged to the outside through the radiator; In heating mode, when the refrigerant pressure and temperature at the compressor inlet are insufficient, the fan is turned on to absorb heat from the external environment through the radiator, increase the coolant temperature, and then transfer the heat to the refrigerant circuit 2 through the water-cooled condenser to increase the refrigerant pressure and temperature at the compressor inlet.

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