Heat-pump-based integrated thermal management system for pure electric vehicle and control method thereof

Abstract

The present application relates to the technical field of heat management, in particular to a pure electric vehicle whole vehicle heat management integrated system based on a heat pump and a control method, comprising a cooling liquid circuit, a water pump one, a heater, an expansion water tank one, a motor, an electric control, a refrigerant circuit one, a refrigerant circuit two, an electronic expansion valve three, a liquid cooling plate, a battery pack and an electromagnetic valve four; the present application integrates and optimizes two components into one, effectively reduces the number of parts, greatly reduces the production cost of the whole vehicle, reduces the weight of the vehicle body, saves the internal space of the engine compartment, and integrates the whole vehicle heat system, absorbs energy from the environment and waste heat, which can greatly improve the endurance mileage, thereby solving the problem of large space occupation of the existing new energy commercial vehicle heat management system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thermal management, in particular to a heat pump-based whole vehicle thermal management integrated system for a pure electric vehicle and a control method thereof. BACKGROUND

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

[0003] Currently, the new energy commercial vehicle thermal management system has the problem of low integration. Some new energy commercial vehicle thermal management systems still use independent cooling systems. The motor and electronic control, battery, and driver's cabin use independent circuits for thermal management control, which makes the system occupy a large space, the overall vehicle weight is heavy, and the use and maintenance cost is high. Compared with integrated thermal management systems, the thermal control efficiency of separate cooling circuits is low and the energy consumption is high. The existing integrated thermal management system has the problem of repeated functions of several components, which leads to low overall heat exchange efficiency of the system. SUMMARY

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

[0005] To achieve the above-mentioned purpose, in a first aspect, the present application provides a heat pump-based whole vehicle thermal management integrated system for a pure electric vehicle, comprising a coolant circuit, a water pump one, a heater, an expansion tank one, a motor, an electronic control, a refrigerant circuit one, a refrigerant circuit two, an electronic expansion valve three, a liquid cooling plate, a battery pack and an electromagnetic valve four.

[0006] The coolant circuit, the water pump one, the heater, the expansion tank one, the motor and the electronic control are connected in sequence; the refrigerant circuit one and the refrigerant circuit two are connected with the coolant circuit respectively; the electronic expansion valve three is connected with the refrigerant circuit one, the refrigerant circuit and the coolant circuit, the liquid cooling plate is connected with the electronic expansion valve three and the battery pack, and the electromagnetic valve four is connected with the liquid cooling plate and the refrigerant circuit one.

[0007] The cooling liquid circuit comprises a three-way valve, a radiator, a fan, a water pump two, an expansion tank two and a water-cooled condenser, the three-way valve is connected with the water pump one, the radiator, the water pump two, the expansion tank two and the water-cooled condenser are connected in sequence, the fan is connected with the radiator, and the water-cooled condenser is connected with the three-way valve.

[0008] The refrigerant circuit one comprises an electronic expansion valve one, an indoor evaporator, a gas-liquid separator, a compressor and an electromagnetic valve one, the electronic expansion valve one is connected with the water-cooled condenser, the electronic expansion valve one, the indoor evaporator, the gas-liquid separator, the compressor and the electromagnetic valve one are connected in sequence, and the electromagnetic valve one is connected with the water-cooled condenser.

[0009] The refrigerant circuit two comprises an electronic expansion valve two, an indoor condenser, an electromagnetic valve two and an electromagnetic valve three, the electronic expansion valve two is connected with the water-cooled condenser, the electronic expansion valve two, the indoor condenser and the electromagnetic valve three are connected in sequence, the electromagnetic valve two is connected with the gas-liquid separator and the water-cooled condenser.

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

[0011] In the refrigeration mode, the high-temperature and high-pressure refrigerant heat in the refrigerant circuit one is transferred to the cooling liquid circuit through the water-cooled condenser, and the temperature in the cooling liquid is discharged to the outdoor through the radiator.

[0012] When the refrigerant pressure and temperature at the inlet of the compressor are insufficient in the heating mode, the fan is started to absorb heat from the external environment through the radiator, so as to increase the temperature of the cooling liquid, and then the heat is transferred to the refrigerant circuit two through the water-cooled condenser, so as to increase the pressure and temperature of the refrigerant at the inlet of the compressor.

[0013] The present invention provides a heat pump-based integrated thermal management system for a pure electric vehicle. The system comprises a water pump for circulating coolant, a heater for auxiliary heating, an expansion tank for replenishing coolant, a motor and an electronic control system generating a large amount of heat during operation, a refrigerant circuit for cooling, a refrigerant circuit for heating, an electronic expansion valve for adjusting the opening to control the refrigerant flow rate, a liquid cooling plate for cooling the battery pack, and a solenoid valve for switching between different circuits. In cooling mode, the refrigerant circuit exchanges heat between the high-temperature, high-pressure refrigerant and the outside air, discharging the heat of the high-temperature refrigerant to the outside. In heating mode, the refrigerant circuit raises the coolant temperature, and the coolant circuit absorbs heat to increase the temperature. The present invention integrates and optimizes two components into one, effectively reducing the number of parts, significantly lowering vehicle manufacturing costs, reducing vehicle weight, and conserving cabin space. Furthermore, the system integrates the vehicle's thermal system, developing thermal management from the perspective of vehicle energy management to maximize energy absorption from the environment and waste heat, significantly improving driving range. This solves the problem of large space requirements for existing thermal management systems for 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 following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 any creative work.

[0015] Figure 1 It is a schematic diagram of the heat pump-based integrated thermal management system for pure electric vehicles 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 the single battery cooling mode.

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

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

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

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

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

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

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

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

[0027] Figure 13 is a schematic diagram of the single battery heating (heat pump + radiator) mode.

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

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

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

[0031] Figure 17 is a schematic diagram of the cab & battery heating (motor waste heat + radiator) mode.

[0032] Figure 18 is a flow chart of the whole vehicle thermal management integrated control method of the heat pump-based pure electric vehicle.

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

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

[0035] Referring to Figures 1 to 17 , the first aspect, the present application provides a pure electric vehicle based on heat pump integrated vehicle thermal management system, including cooling liquid circuit, water pump 1, heater 2, expansion tank 1, motor 4, electric control 5, refrigerant circuit 1, refrigerant circuit 2, electronic expansion valve three 6, liquid cooling plate 7, battery pack 8 and solenoid valve four 9;

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

[0037] In this embodiment, the water pump 1 is used to realize the circulation of cooling liquid, the heater 2 is used to assist heating, the expansion tank 1 is used to supplement the cooling liquid, the motor 4 and the electric control 5 generate a large amount of heat when working, the refrigerant circuit 1 is used for refrigeration mode, the refrigerant circuit 2 is used for heating mode, the electronic expansion valve three 6 is used for opening degree adjustment control of refrigerant flow, the liquid cooling plate 7 is used for cooling the battery pack 8, and the solenoid valve four 9 is used for different circuit switching. In the refrigeration mode, the refrigerant circuit 1 exchanges heat with the outside air to discharge high-temperature refrigerant heat to the outdoor; in the heating mode, the refrigerant circuit 2 increases the temperature of the cooling liquid to absorb heat in the cooling liquid circuit. The present application integrates two components into one, effectively reduces the number of components, greatly reduces the production cost of the whole vehicle, reduces the weight of the vehicle body, saves the internal space of the engine compartment, and integrates the whole vehicle heat system. From the perspective of energy management, the heat management development absorbs energy from the environment and waste heat as much as possible, which can greatly improve the endurance mileage, thereby solving the problem of large space occupation of the existing new energy commercial vehicle heat management system.

[0038] Further, the cooling liquid circuit comprises a three-way valve 10, a radiator 11, a fan 12, a water pump 13, an expansion tank 14 and a water-cooled condenser 15, the three-way valve 10 is connected with the water pump 1, the radiator 11, the water pump 13, the expansion tank 14 and the water-cooled condenser 15 are connected in turn, the fan 12 is connected with the radiator 11, and the water-cooled condenser 15 is connected with the three-way valve 10.

[0039] In the 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 driving motor 4, the heat recovery of the motor 4 and the condensation function of the refrigerant. The radiator 11 is used for heat dissipation, the fan 12 is used to force air flow through the surface of the front-end radiator 11 to realize the cooling of the refrigerant and the cooling liquid, the water pump two 13 is used to realize the circulation of the cooling liquid circuit, the expansion tank two 14 is used to store the cooling liquid, and the water-cooled condenser 15 is used to absorb the high-temperature cooling liquid in the water circuit, and the waste heat of the motor 4 is recovered and used at the same time.

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

[0041] In the embodiment, the electronic expansion valve one 16 realizes the control of the refrigerant flow of the refrigeration device by opening degree adjustment, the indoor evaporator 17 realizes the cooling of the cabin inlet air by expanding and vaporizing the refrigerant in the indoor evaporator 17 to absorb heat, the gas-liquid separator 18 is used to absorb the liquid in the refrigerant to prevent the liquid from entering the compressor 19, and the compressor 19 compresses the low-temperature and low-pressure gaseous refrigerant into high-temperature and high-pressure gaseous refrigerant. The electromagnetic valve one 20 realizes the switching of different circuits of the heat pump air conditioner to realize the refrigeration function.

[0042] Further, the refrigerant circuit two includes an electronic expansion valve two 21, an indoor condenser 22, an electromagnetic valve two 23 and an electromagnetic valve three 24; the electronic expansion valve two 21 is connected with the water-cooled condenser 15, the electronic expansion valve two 21, the indoor condenser 22 and the electromagnetic valve three 24 are connected in sequence, the electromagnetic valve two 23 is connected with the gas-liquid separator 18 and the water-cooled condenser 15.

[0043] In the embodiment, the electronic expansion valve two 21 realizes the control of the refrigerant flow of the refrigeration device by opening degree adjustment. The indoor condenser 22 realizes the heating of the low-cabin inlet air by condensing and liquefying the refrigerant in the indoor condenser 22 to release heat. The electromagnetic valve two 23 and the electromagnetic valve three 24 realize the switching of different circuits of the heat pump air conditioner to realize the heating function.

[0044] Figure 2 Motor electric control heat dissipation mode:

[0045] The cab has refrigeration demand, and the battery has no refrigeration and heating demand. The high-temperature and high-pressure refrigerant is cooled by the outdoor radiator, becomes low-temperature and low-pressure state through the electronic expansion valve EXV1, is heated by the indoor evaporator, and achieves the refrigeration effect in the cab. Working condition: the air conditioner refrigeration switch is turned on, the knob is rotated to the refrigeration position, and the maximum battery temperature is less than or equal to 35 DEG C. Execution action: SOV1 is turned on, SOV2, 3 and 4 are turned off, the opening degree of the electronic expansion valve EXV1 is adjusted according to the supercooling degree of the refrigerant at the evaporative condenser, EXV2 and 3 are turned off, the fan and the compressor are turned on and work, the water pump two is turned on, and the 1 and 2 channels of the three-way valve are connected.

[0046] Figure 3 Single cab refrigeration:

[0047] When the cab has no refrigeration demand and the battery temperature is too high and needs refrigeration, the high-temperature and high-pressure refrigerant is cooled by the outdoor radiator, becomes low-temperature and low-pressure state through the electronic expansion valve EXV3, and is cooled by the liquid cooling plate to cool the battery pack. Working condition: the air conditioner refrigeration switch is turned off, the knob is rotated to the refrigeration position, and the maximum battery temperature is greater than 35 DEG C. Execution action: SOV1 and 4 are turned on, SOV2 and 3 are turned off, the opening degree of the electronic expansion valve EXV3 is adjusted according to the supercooling degree of the refrigerant at the liquid cooling plate, EXV1 and 2 are turned off, the fan and the compressor are turned on and work, the water pump two is turned on, and the 1 and 2 channels of the three-way valve are connected.

[0048] Figure 4 Single battery refrigeration mode:

[0049] When the cab and the battery have refrigeration demand at the same time, the high-temperature and high-pressure refrigerant is cooled by the outdoor radiator, becomes low-temperature and low-pressure state through the electronic expansion valves EXV1 and 3, and is cooled by the liquid cooling plate and the indoor evaporator respectively to cool the cab and the battery pack. Working condition: the air conditioner refrigeration switch is turned on, the knob is rotated to the refrigeration position, and the maximum battery temperature is greater than 35 DEG C. Execution action: SOV1 and 4 are turned on, SOV2 and 3 are turned off, the opening degree of the electronic expansion valve EXV3 is adjusted according to the supercooling degree of the refrigerant at the liquid cooling plate, the opening degree of the electronic expansion valve EXV1 is adjusted according to the supercooling degree of the refrigerant at the evaporative condenser, EXV2 is turned off, the fan and the compressor are turned on and work, the water pump two is turned on, and the 1 and 2 channels of the three-way valve are connected.

[0050] Figure 5 Cab & battery refrigeration mode:

[0051] The cab has heating demand, the battery has no refrigeration and heating demand, the PTC is started to heat the coolant when the ambient temperature is too low, the high-temperature refrigerant supplies heat to the cab through the indoor condenser, the refrigerant absorbs heat from the heated coolant through the LCC after passing through the expansion valve, and the heating cycle is completed. Working condition: water temperature < 0°C and ambient temperature < -10°C. Action: SOV2, 3 are started, SOV1, 4 are stopped, the opening degree of the electronic expansion valve EXV2 is adjusted according to the superheat degree of the refrigerant at the indoor condenser, EXV1, 3 are stopped, the three-way valve 2, 3 is connected, the compressor is started to work, the water pump is started, and the PTC is started to heat the coolant.

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

[0053] The cab has heating demand, the battery has no refrigeration and heating demand, the water temperature difference with the ambient temperature is insufficient, the refrigerant absorbs heat from the environment after being heated by the outdoor radiator, and the water temperature difference is already small, so the water pump is stopped and only heat is absorbed from the outdoor environment. Working condition: 0 < water temperature < 25°C and water temperature - ambient temperature < 5°C. Action: SOV2, 3 are started, SOV1, 4 are stopped, the opening degree of the electronic expansion valve EXV2 is adjusted according to the superheat degree of the refrigerant at the indoor condenser, EXV1, 3 are stopped, the fan and the compressor are started to work, the water pump is started, and the three-way valve 1, 2 is connected.

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

[0055] The air conditioner is started to heat, the battery has no refrigeration and heating demand, the ambient temperature is too low, or the water temperature is high enough, the fan is stopped, the motor coolant circuit is connected, the refrigerant no longer absorbs heat from the outside, but absorbs heat from the coolant when passing through the LCC. Working condition: water temperature ≥ 25°C. Action: SOV2, 3 are started, SOV1, 4 are stopped, the opening degree of the electronic expansion valve EXV2 is adjusted according to the superheat degree of the refrigerant at the indoor condenser, EXV1, 3 are stopped, the three-way valve 2, 3 is connected, the water pump and the compressor are started to work.

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

[0057] Air conditioner starts heating, battery has no cooling and heating demand, but water temperature is too high, fan starts, three-way valve opens completely, part of cooling liquid is diverted to radiator for heat dissipation, and the other part transmits heat to refrigerant through LCC. Working condition: 0 < water temperature < 25℃ and water temperature - ambient temperature ≥ 5℃ and ambient temperature > -10℃. Execution action: SOV2, 3 open, SOV1, 4 close, electronic expansion valve EXV2 opening degree is adjusted according to refrigerant superheat at indoor condenser, EXV1, 3 close, 1, 2, 3 channels of three-way valve are connected, water pump one, fan and compressor start working.

[0058] Figure 9 Single cab heating (heat pump + radiator) mode:

[0059] Cab has no cooling and heating demand, battery has heating demand, ambient temperature is too low, and water temperature of motor is insufficient, heat absorption from environment is too slow, PTC is started to provide heat for cooling liquid, and refrigerant absorbs heat in cooling liquid to supply battery pack in LCC. Working condition: -5 ≤ water temperature < 0℃ and ambient temperature < -10℃. Execution action: SOV2, 3 open, SOV1, 4 close, electronic expansion valve EXV3 opening degree is adjusted according to refrigerant superheat at liquid cooling plate, EXV1, 2 close, 2, 3 channels of three-way valve are connected, PTC, water pump one and compressor start working.

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

[0061] Cab has no cooling and heating demand, battery has heating demand, water temperature difference with ambient temperature is insufficient, compressor, fan and water pump two are started, and refrigerant absorbs heat from outside environment. Working condition: 0 ≤ water temperature < 25℃ and water temperature - ambient temperature < 5℃. Execution action: SOV2, 3 open, SOV1, 4 close, electronic expansion valve EXV3 opening degree is adjusted according to refrigerant superheat at liquid cooling plate, EXV1, 2 close, water pump two, fan and compressor start working, and 1, 2 channels of three-way valve are connected.

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

[0063] Cab has no cooling and heating demand, battery has heating demand, ambient temperature is too low, fan is closed, and refrigerant absorbs heat in motor loop cooling liquid through LCC after heat release at liquid cooling plate. Working condition: 0 < water temperature < 25℃ and water temperature - ambient temperature ≥ 5℃ and ambient temperature < -10℃. Execution action: SOV2, 3 open, SOV1, 4 close, electronic expansion valve EXV3 opening degree is adjusted according to refrigerant superheat at liquid cooling plate, EXV1, 2 close, 2, 3 channels of three-way valve are connected, water pump one and compressor start working.

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

[0065] Battery heating is required, and the cab has no cooling and heating requirements, but when the water temperature is too high, the fan is turned on, the three-way valve is fully opened, part of the cooling liquid is diverted to the radiator for cooling, and the other part transmits heat to the refrigerant through the LCC. Working condition: 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 degree of EXV2 is adjusted according to the refrigerant superheat at the indoor condenser, EXV1, 3 are closed, the 1, 2, 3 channels of the three-way valve are connected, the water pump, the fan, and the compressor are turned on.

[0066] Figure 13 Single battery heating (heat pump + radiator) mode:

[0067] The cab has heating requirements, the battery has heating requirements, and the environment temperature is too low, so the heating efficiency is too slow when only absorbing heat from the environment. Turn off the fan, turn on the W-PTC to provide heat to the system, and the refrigerant absorbs the heat in the cooling liquid through the LCC. Working condition: water temperature < 0℃ and ambient temperature < -10℃. Execution action: SOV2, 3 are opened, SOV1, 4 are closed, the opening degree of EXV3 is adjusted according to the refrigerant superheat at the liquid cooling plate, the opening degree of EXV2 is adjusted according to the refrigerant superheat at the indoor condenser, EXV1 is closed, the 2, 3 channels of the three-way valve are connected, the water pump, the PTC, and the compressor are turned on.

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

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

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

[0071] The cab has heating demand, the battery has heating demand, the environment temperature is too low, the fan is closed, and the refrigerant absorbs heat in the motor circuit cooling liquid through the LCC after heat release through the liquid cooling plate. Working condition: 0 < water temperature < 25℃ and water temperature - environment temperature ≥ 5℃ and environment temperature < -10℃. Execution action: SOV2, 3 are opened, SOV1, 4 are closed, the opening degree of the electronic expansion valve EXV3 is adjusted according to the refrigerant superheat at the liquid cooling plate, the opening degree of the electronic expansion valve EXV2 is adjusted according to the refrigerant superheat at the indoor condenser, EXV1 is closed, the 1, 2, 3 channels of the three-way valve are connected, and the water pump one, the compressor are opened and work.

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

[0073] The cab has heating demand, the battery has heating demand, the cooling liquid water temperature is too high, the three-way valve is fully opened, a part of the cooling liquid is branched to release heat in the radiator, a part of the cooling liquid passes through the LCC to transfer heat to the refrigerant, and then supplies the indoor condenser and the liquid cooling plate to heat the indoor and the battery pack. Working condition: water temperature ≥ 35℃. Execution action: SOV2, 3 are opened, SOV1, 4 are closed, the opening degree of the electronic expansion valve EXV3 is adjusted according to the refrigerant superheat at the liquid cooling plate, the opening degree of the electronic expansion valve EXV2 is adjusted according to the refrigerant superheat at the indoor condenser, EXV1 is closed, the 1, 2, 3 channels of the three-way valve are connected, and the water pump one, the fan, the compressor are opened and work.

[0074] Figure 17 Cab & battery heating (motor waste heat + radiator):

[0075] Dehumidification mode When the dehumidification switch is opened, the indoor evaporator and the indoor condenser are opened at the same time. The air with high humidity is cooled and cooled by the evaporator first, and then the water is condensed and discharged. The air is dried by the indoor condenser. Working condition: When the dehumidification switch is opened.

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

[0077] Please refer to Figure 18 , in a second aspect, a whole vehicle thermal management integrated control method based on a heat pump for the whole vehicle thermal management integrated system based on the heat pump in the first aspect, comprising the following steps:

[0078] S1 In the refrigeration mode, the high-temperature and high-pressure refrigerant heat in the refrigerant circuit one is transferred to the cooling liquid circuit through the water-cooled condenser, and then the temperature of the cooling liquid is discharged to the outdoor through the radiator.

[0079] Specifically, when the high-temperature and high-pressure refrigerant is discharged from the compressor, heat exchange is performed with the motor and the electronic control circuit through the water-cooled condenser LCC, at this time, the three-way valve in the cooling liquid circuit is connected to the 1 and 2 ports, at this time, the temperature of the cooling liquid circuit is obviously lower than the temperature of the refrigerant at the outlet of the compressor, so the heat flows from the refrigerant circuit to the cooling liquid circuit. The water pump 2 is turned on to work, and the cooling liquid of the motor and the electronic control circuit starts to circulate through the radiator to exchange the heat exchanged from the refrigerant circuit, and the heat is discharged to the outside through the radiator, which plays a role of cooling the refrigerant, thereby achieving the purpose of replacing the outdoor condenser with the outdoor radiator.

[0080] S2 opens the fan when the pressure and temperature of the refrigerant at the inlet of the compressor are insufficient in the heating mode, absorbs heat from the external environment through the radiator to increase the temperature of the cooling liquid, and then transmits the heat to the refrigerant circuit 2 through the water-cooled condenser to increase the pressure and temperature of the refrigerant at the inlet of the compressor.

[0081] Specifically, when the high-temperature and high-pressure refrigerant is discharged from the compressor, heat exchange is performed with the motor and the electronic control circuit through the water-cooled condenser LCC, at this time, the three-way valve in the cooling liquid circuit is connected to the 1 and 2 ports, at this time, the temperature of the cooling liquid circuit is obviously lower than the temperature of the refrigerant at the outlet of the compressor, so the heat flows from the refrigerant circuit to the cooling liquid circuit. The water pump 2 is turned on to work, and the cooling liquid of the motor and the electronic control circuit starts to circulate through the radiator to exchange the heat exchanged from the refrigerant circuit, and the heat is discharged to the outside through the radiator, which plays a role of cooling the refrigerant, thereby achieving the purpose of replacing the outdoor condenser with the outdoor radiator.

[0082] The above only discloses the preferred embodiment of the whole vehicle thermal management integrated system and control method of the pure electric vehicle based on the heat pump of the present application, of course, cannot limit the scope of the rights of the present application, and those skilled in the art can understand that the whole or part of the above-mentioned embodiment is implemented, and the equivalent changes made according to the claims of the present application still belong to the scope covered by the present application.

Claims

1. A heat pump-based pure electric vehicle integrated thermal management system, characterized in that: it comprises a coolant circuit, a water pump I, a heater, an expansion tank I, an electric motor, an electric control, a refrigerant circuit I, a refrigerant circuit II, an electronic expansion valve III, a liquid cooling plate, a battery pack, and an electromagnetic valve IV; the coolant circuit, the water pump I, the heater, the expansion tank I, the electric motor, and the electric control are connected in sequence; the refrigerant circuit I and the refrigerant circuit II are connected with the coolant circuit respectively; the electronic expansion valve III is connected with the refrigerant circuit I, the refrigerant circuit, and the coolant circuit, the liquid cooling plate is connected with the electronic expansion valve III and the battery pack, and the electromagnetic valve IV is connected with the liquid cooling plate and the refrigerant circuit I; the coolant circuit comprises a three-way valve, a radiator, a fan, a water pump II, an expansion tank II, and a water-cooled condenser; the three-way valve is connected with the water pump I; the radiator, the water pump II, the expansion tank II, and the water-cooled condenser are connected in sequence; the fan is connected with the radiator; and the water-cooled condenser is connected with the three-way valve; the refrigerant circuit I comprises an electronic expansion valve I, an indoor evaporator, a gas-liquid separator, a compressor, and an electromagnetic valve I; the electronic expansion valve I is connected with the water-cooled condenser; the electronic expansion valve I, the indoor evaporator, the gas-liquid separator, the compressor, and the electromagnetic valve I are connected in sequence; and the electromagnetic valve I is connected with the water-cooled condenser; the refrigerant circuit II comprises an electronic expansion valve II, an indoor condenser, an electromagnetic valve II, and an electromagnetic valve III; the electronic expansion valve II is connected with the water-cooled condenser; the electronic expansion valve II, the indoor condenser, and the electromagnetic valve III are connected in sequence; and the electromagnetic valve II is connected with the gas-liquid separator and the water-cooled condenser.

2. The integrated control method for the whole vehicle thermal management of the heat pump-based pure electric vehicle, applied to the integrated system for the whole vehicle thermal management of the heat pump-based pure electric vehicle according to claim 1, characterized in that: The steps include: in the refrigeration mode, the high-temperature and high-pressure refrigerant heat in the refrigerant circuit I is transferred to the coolant circuit through the water-cooled condenser, and then the temperature of the coolant is discharged to the outdoor through the radiator; in the heating mode, when the refrigerant pressure and temperature at the inlet of the compressor are insufficient, the fan is started to absorb heat from the external environment through the radiator, thereby increasing the temperature of the coolant, and then transferring the heat to the refrigerant circuit II through the water-cooled condenser to increase the pressure and temperature of the refrigerant at the inlet of the compressor.

Images