An integrated thermal management system for pure electric commercial vehicles based on an indirect heat pump

Abstract

The present invention relates to the field of thermal management technology, and specifically to an integrated thermal management system for pure electric commercial vehicles based on an indirect heat pump, comprising an expansion water tank, a waste heat circuit, a refrigerant circuit, a battery pack, and a coolant circuit. The present invention adopts an expansion water tank, a waste heat circuit, a refrigerant circuit, a battery pack, and a coolant circuit. When the heating environment temperature is low in winter, the direct heat pump compressor may not be able to start. By transferring heat through the coolant, heat can be exchanged not only with the battery pack, but also with the air in the cab, which can better achieve heat control and distribution. The indirect heat pump can make better use of the environmental heat source, save energy more effectively, and reduce operating costs. This solves the problem of traditional heat pump systems being difficult to start in winter.

Description

Technical Field

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

[0002] Most new energy commercial vehicles lack a high level of thermal management system integration. Typically, the battery pack circuit and air conditioning circuit are connected in parallel via a heat exchanger, while the motor and electronic control cooling circuit operate independently. This system has too many components, taking up significant cabin space. Furthermore, heat from the motor and electronic control circuit is discharged outside the vehicle, rather than being fully recycled. This results in low overall thermal management efficiency, significantly impacting the vehicle's range.

[0003] Currently, some new energy commercial vehicles utilize direct heat pumps, which route the refrigerant circuit directly to the evaporator or condenser in the cab to achieve cooling or heating. However, direct heat pumps have challenging startup requirements in low-temperature environments, and their heating efficiency significantly decreases when the ambient temperature is low. Summary of the Invention

[0004] The purpose of the present invention is to provide an integrated thermal management system for pure electric commercial vehicles based on an indirect heat pump, aiming to solve the problem that traditional heat pump systems are difficult to start in winter.

[0005] To achieve the above objectives, the present invention provides an integrated thermal management system for a pure electric commercial vehicle based on an indirect heat pump, comprising an expansion water tank, a waste heat circuit, a refrigerant circuit, a battery pack, and a coolant circuit;

[0006] The waste heat circuit is connected to the expansion water tank, the refrigerant circuit is connected to the waste heat circuit, the battery pack is connected to the coolant circuit, the coolant circuit is connected to the refrigerant circuit, and is connected to the waste heat circuit.

[0007] Among them, the waste heat circuit includes a water pump 1, a temperature sensor 1, an electronic control, a motor, a three-way valve 1, a water-cooled condenser 2 and a four-way valve 1, and the water pump 1, the temperature sensor 1, the electronic control, the motor, the three-way valve 1, the water-cooled condenser 2 and the four-way valve 1 are connected in sequence.

[0008] Among them, the refrigerant circuit includes a compressor, a second three-way valve, a first water-cooled condenser, a first temperature and pressure sensor, a second temperature and pressure sensor, a third temperature and pressure sensor, a condenser, a gas-liquid separator, a solenoid valve and an electronic expansion valve. The compressor, the second three-way valve, the first water-cooled condenser, the second temperature and pressure sensor, the electronic expansion valve, the condenser, the third temperature and pressure sensor, the solenoid valve, the gas-liquid separator and the first temperature and pressure sensor are connected in sequence.

[0009] Among them, the coolant circuit includes water pump 2, expansion water tank 2, three-way valve 3, heater, liquid cooling plate, indoor heat exchanger, temperature sensor 2, temperature sensor 3 and temperature sensor 4; the expansion water tank 2, the water pump 2, the heater, the three-way valve 3, the indoor heat exchanger, and the temperature sensor 4 are connected in sequence, and the temperature sensor 2, the liquid cooling plate, and the temperature sensor 3 are connected in sequence.

[0010] The integrated thermal management system for pure electric commercial vehicles based on an indirect heat pump further includes an evaporator, which is connected to the refrigerant circuit.

[0011] The present invention provides an integrated thermal management system for pure electric commercial vehicles based on an indirect heat pump, comprising an expansion water tank 1, a waste heat circuit, a refrigerant circuit, a battery pack, and a coolant circuit; the waste heat circuit is connected to the expansion water tank 1, the refrigerant circuit is connected to the waste heat circuit, the battery pack is connected to the coolant circuit, the coolant circuit is connected to the refrigerant circuit, and is connected to the waste heat circuit. The present invention adopts an expansion water tank 1, a waste heat circuit, a refrigerant circuit, a battery pack, and a coolant circuit. When the heating environment temperature is low in winter, the direct heat pump compressor may not be able to start. By transferring heat through the coolant, heat can be exchanged not only with the battery pack, but also with the air in the cab, which can better achieve heat control and distribution. The indirect heat pump can make better use of the environmental heat source, save energy more effectively, and reduce operating costs. This solves the problem of traditional heat pump systems being difficult to start in winter. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] 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.

[0013] Figure 1 This is a schematic diagram of an integrated thermal management system for a pure electric commercial vehicle based on an indirect heat pump provided by the present invention.

[0014] Figure 2 It is a schematic diagram of the self-circulating mode.

[0015] Figure 3 It is a schematic diagram of the motor electronic control heat dissipation mode.

[0016] Figure 4 It is a schematic diagram of the battery heat dissipation mode.

[0017] Figure 5 It is a schematic diagram of the single cab cooling mode.

[0018] Figure 6 It is a schematic diagram of the single battery cooling mode.

[0019] Figure 7 This is a schematic diagram of the cab and battery pack cooling mode.

[0020] Figure 8 This is a schematic diagram of the single cab heating (PTC) mode.

[0021] Figure 9 This is a schematic diagram of the single cab heating (PTC+heat pump) mode.

[0022] Figure 10 This is a schematic diagram of the single cab heating (heat pump) mode.

[0023] Figure 11 This is a schematic diagram of single cab heating (heat pump + waste heat recovery) mode 1.

[0024] Figure 12 This is a schematic diagram of single cab heating (heat pump + waste heat recovery) mode 2.

[0025] Figure 13 This is a schematic diagram of the single cab heating (heat pump + cooling) mode.

[0026] Figure 14 This is a schematic diagram of the single cab heating (waste heat recovery) mode.

[0027] Figure 15 This is a schematic diagram of the single-cell heating (PTC) mode.

[0028] Figure 16 This is a schematic diagram of the single-battery heating (heat pump + PTC) mode.

[0029] Figure 17 This is a schematic diagram of the single-battery heating (heat pump) mode.

[0030] Figure 18 This is a schematic diagram of single-battery heating (heat pump + waste heat recovery) mode 1.

[0031] Figure 19 This is a schematic diagram of single-battery heating (heat pump + waste heat recovery) mode 2.

[0032] Figure 20 This is a schematic diagram of the single-battery heating (motor waste heat) mode.

[0033] Figure 21 This is a schematic diagram of the single-battery heating (motor waste heat + heat dissipation) mode.

[0034] Figure 22 This is a schematic diagram of the cab & battery heating (PTC) mode.

[0035] Figure 23 This is a schematic diagram of the cab & battery heating (heat pump + PTC) mode.

[0036] Figure 24 This is a schematic diagram of the cab & battery heating (heat pump) mode.

[0037] Figure 25 This is a schematic diagram of cab & battery heating (heat pump + waste heat recovery) mode 1.

[0038] Figure 26 This is a schematic diagram of cab & battery heating (heat pump + waste heat recovery) mode 2.

[0039] Figure 27 This is a schematic diagram of the cab & battery heating (waste heat recovery) mode.

[0040] Figure 28 This is a schematic diagram of the cab & battery heating (waste heat recovery + heat dissipation) mode.

[0041] Figure 29 It is a schematic diagram of the outdoor condenser defrost mode.

[0042] In the figure: 1-water pump 1, 2-temperature sensor 1, 3-electronic control, 4-motor, 5-three-way valve 1, 6-water-cooled condenser 2, 7-four-way valve 1, 8-compressor, 9-three-way valve 2, 10-water-cooled condenser 1, 11-temperature and pressure sensor 1, 12-temperature and pressure sensor 2, 13-temperature and pressure sensor 3, 14-condenser, 15-gas-liquid separator, 16-solenoid valve, 17-electronic expansion valve, 18-water pump 2, 19-expansion water tank 2, 20-three-way valve 2, 21-heater, 22-liquid cooling plate, 23-indoor heat exchanger, 24-temperature sensor 2, 25-temperature sensor 3, 26-temperature sensor 4, 27-evaporator, 28-expansion water tank 1, 29-battery pack DETAILED DESCRIPTION

[0043] The following describes embodiments of the present invention in detail, 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 are not to be construed as limiting the present invention.

[0044] See also Figures 1 to 29 The present invention provides an integrated thermal management system for a pure electric commercial vehicle based on an indirect heat pump, comprising an expansion water tank 28, a waste heat circuit, a refrigerant circuit, a battery pack 29 and a coolant circuit;

[0045] The waste heat circuit is connected to the expansion water tank 28, the refrigerant circuit is connected to the waste heat circuit, the battery pack 29 is connected to the coolant circuit, the coolant circuit is connected to the refrigerant circuit, and is connected to the waste heat circuit.

[0046] In this embodiment, the present invention utilizes an expansion tank 28, a waste heat circuit, a refrigerant circuit, a battery pack 29, and a coolant circuit. In winter, when the ambient heating temperature is low, a direct heat pump compressor may be unable to start. The present invention uses coolant to transfer heat, exchanging heat not only with the battery pack 29 but also with the air in the cab, enabling better heat control and distribution. An indirect heat pump can more fully utilize ambient heat sources, more effectively conserve energy, and reduce operating costs. This solves the winter startup difficulty of traditional heat pump systems.

[0047] Furthermore, the waste heat circuit includes a water pump 1, a temperature sensor 2, an electronic control 3, a motor 4, a three-way valve 5, a water-cooled condenser 2 6 and a four-way valve 7, and the water pump 1, the temperature sensor 2, the electronic control 3, the motor 4, the three-way valve 5, the water-cooled condenser 2 6 and the four-way valve 7 are connected in sequence.

[0048] In this embodiment, the motor 4 electronic control 3 generates a large amount of heat when the vehicle is running, causing the water temperature of the motor 4 electronic control 3 circuit to rise rapidly. In winter or when the ambient temperature is too low, the vapor pressure of the refrigerant in the refrigerant circuit is low, the compressor 8 inhales less gas, the starting load is large, and it is easy to get stuck. At this time, the coolant in the motor 4 electronic control 3 circuit flows through LCC2, transferring heat to the refrigerant vapor that is about to enter the inlet of the compressor 8, causing its temperature to rise and the pressure to be sufficient to meet the normal start-up of the compressor 8. Transferring the temperature of the coolant in the motor 4 electronic control 3 circuit to the refrigerant circuit not only protects the motor 4 electronic control 3 and other components from overheating, but also allows the compressor 8 to start normally in an ultra-low temperature environment, which is the waste heat recovery function.

[0049] Furthermore, the refrigerant circuit includes a compressor 8, a three-way valve 2 9, a water-cooled condenser 10, a temperature and pressure sensor 1 11, a temperature and pressure sensor 2 12, a temperature and pressure sensor 3 13, a condenser 14, a gas-liquid separator 15, a solenoid valve 16 and an electronic expansion valve 17. The compressor 8, the three-way valve 2 9, the water-cooled condenser 10, the temperature and pressure sensor 2 12, the electronic expansion valve 17, the condenser 14, the temperature and pressure sensor 3 13, the solenoid valve 16, the gas-liquid separator 15 and the temperature and pressure sensor 1 11 are connected in sequence.

[0050] In this embodiment, after being discharged from the outlet of compressor 8, the high-temperature, high-pressure refrigerant passes through the three-way valve 1-2 channel and enters LCC1 to exchange heat with the coolant circuit. At this point, the coolant temperature is significantly lower than the refrigerant temperature, so heat is transferred from the refrigerant to the coolant circuit. After exiting LCC1, the refrigerant is throttled by electronic expansion valve 17 and converted to a low-temperature, low-pressure refrigerant state. It then absorbs heat from the outside world through condenser 14 and a fan. After the temperature is raised, the refrigerant passes through gas-liquid separator 15 and re-enters the inlet of compressor 8, completing the refrigerant circuit.

[0051] Furthermore, the coolant circuit includes a water pump 2 18, an expansion water tank 2 19, a three-way valve 3 20, a heater 21, a liquid cooling plate 22, an indoor heat exchanger 23, a temperature sensor 2 24, a temperature sensor 3 25 and a temperature sensor 4 26; the expansion water tank 2 19, the water pump 2 18, the heater 21, the three-way valve 3 20, the indoor heat exchanger 23, and the temperature sensor 4 26 are connected in sequence, and the temperature sensor 2 24, the liquid cooling plate 22, and the temperature sensor 3 25 are connected in sequence.

[0052] In this embodiment, when the ambient temperature is suitable, the compressor 8 can operate normally. After the coolant circuit absorbs the heat transferred from the high-temperature and high-pressure refrigerant at LCC1, it is diverted by a three-way valve and flows through the liquid cooling plate 22 and the indoor heat exchanger 23 respectively. After heating the battery pack and the indoor heat exchanger 23, it rejoins and returns to the expansion tank, completing the coolant circuit cycle. When the ambient temperature is too low, the compressor 8 is difficult to start. At this time, the compressor 8 can complete normal startup by increasing the refrigerant inlet pressure through the waste heat recovery function. Alternatively, a W-PTC thermistor can be used to directly supply heat to the coolant circuit.

[0053] Furthermore, the integrated thermal management system for pure electric commercial vehicles based on an indirect heat pump further includes an evaporator 27 , which is connected to the refrigerant circuit.

[0054] In this embodiment, the refrigerant expands and vaporizes in the evaporator 27 to absorb heat, and the cool air is blown out by the blower to exchange heat with the indoor hot air for cooling operation.

[0055] The compressor is used to compress the refrigerant, increase its pressure and reduce its volume; the condenser is used to complete the absorption and release of heat by the refrigerant from the air; the evaporator is used for the refrigerant to expand and vaporize in the evaporator to absorb heat, and the cold air is blown out by the blower to exchange heat with the indoor hot air, which is used for cooling conditions; the indoor heat exchanger is used for high-temperature coolant to flow through the indoor heat exchanger, and the heat is blown out by the blower to exchange heat with the indoor cold air, which is used for heating conditions; the radiator is used for the coolant to blow out the heat in the radiator through the fan to achieve the purpose of heat dissipation; the electronic water pump 1 is used to realize the circulation of the coolant in the motor electronic control circuit; the electronic water pump 2 is used to realize the circulation of the coolant in the battery pack circuit and the indoor heat exchanger circuit; the expansion Water tank 1 is used to replenish the coolant in the radiator and the motor electronic control circuit; the expansion water tank 2 is used to replenish the coolant in the battery pack circuit and the indoor heat exchanger circuit; the water-cooled condenser (LCC1) is used to complete the heat exchange between the refrigerant circuit and the battery pack circuit and the indoor heat exchanger circuit; the water-cooled condenser (LCC2) is used to complete the heat exchange between the refrigerant circuit and the motor electronic control circuit; the refrigeration device (Chiller) realizes the heat exchange between the refrigerant circuit and the battery pack circuit, which is used for cooling conditions; the blower is used to accelerate the heat exchange between the evaporator and the indoor heat exchanger and the air in the cab by forcing air flow; W-PTC uses the PTC thermistor as a heat source to heat the coolant; the gas-liquid separator is used to prevent liquid When the refrigerant enters the compressor, liquid hammer occurs; the three-way valve is used to switch the flow channels of different working conditions by adjusting the size of the caliber and the switch; the four-way valve is used to switch the series and parallel connection of the battery circuit and the motor electronic control circuit through the four-way valve to realize the switching of the motor's waste heat recovery and heat dissipation; the solenoid valve (Sov) is used to switch different circuits of the heat pump air conditioner by reasonably controlling the solenoid valve switch to complete the conversion of different working conditions; the electronic expansion valve (EXV1, EXV2, EXV3) realizes the refrigerant flow control of the refrigerant circuit by adjusting the opening; the pressure and temperature sensor (PT1) measures the inlet temperature and pressure of the compressor as the compressor control index; the pressure and temperature sensor (PT2) measures the temperature of the refrigerant at the outlet of LCC1 The temperature and pressure of the refrigerant at the outlet of LCC1 are used to calculate the subcooling degree of the refrigerant at the outlet of LCC1; the pressure and temperature sensor (PT3) measures the temperature and pressure of the refrigerant at the outlet of the condenser, which are used to calculate the subcooling degree of the refrigerant at the outlet of the condenser; the pressure and temperature sensor (PT4) measures the temperature and pressure of the refrigerant at the outlet of the chiller, which are used to calculate the superheat degree of the refrigerant at the outlet of the chiller; the pressure and temperature sensor (PT5) measures the temperature and pressure of the refrigerant at the outlet of the evaporator, which are used to calculate the superheat degree of the refrigerant at the outlet of the evaporator; the temperature sensor (T1) measures the temperature of the coolant in the motor electronic control circuit; the temperature sensor (T2) measures the temperature of the coolant at the inlet of the liquid cooling plate; the temperature sensor (T3) measures the temperature of the coolant at the outlet of the liquid cooling plate;Temperature sensor (T4), measuring the temperature of the coolant at the outlet of the indoor heat exchanger.

[0056] 1. Self-circulation mode: When the battery temperature difference is too large, the temperature difference between all cells must be kept small to ensure normal operation. In this mode, no heat exchangers are activated, and only water pump 2 is activated as needed to circulate coolant to reduce the temperature difference between the cells. Operating conditions: Maximum battery temperature - minimum battery temperature ≥ 8°C. Execution: Connect four-way valves 1 and 2, activate water pump 2, and connect three-way valves 1 and 3 in the battery pack circuit.

[0057] 2. Motor Control Cooling Mode: If the motor control temperature is too high, the motor circuit water pump and fan are activated, circulating coolant to remove heat from the motor and dissipating it outdoors through the radiator in the motor circuit. Operating Condition: In charging mode or idling, when the motor control temperature is ≥40°C. Execution: Connect four-way valves 3-4, start water pump 1, and connect three-way valves 2-3 in the motor control circuit.

[0058] 3. Battery Cooling Mode: If the battery pack temperature is too high, the four-way valve connects the motor control circuit and the battery pack circuit. Both water pumps are turned on, and the coolant circuit completes a full cycle, discharging the battery pack heat to the outside through the radiator. Operating Conditions: In charging mode or idling, when the battery pack temperature is ≥40°C and the ambient temperature is ≤30°C. Execution: Connect four-way valves 2-3 and 1-4, connect three-way valves 2-3 of the motor control circuit, connect three-way valves 1-3 of the battery pack circuit, turn on water pumps 1 and 2, and turn on the fan.

[0059] 4. Single Cab Cooling Mode: The cab requires cooling, but the battery pack does not. High-temperature, high-pressure refrigerant releases heat through the condenser, then passes through electronic expansion valve EXV1 to a low-temperature, low-pressure state. Heat is absorbed by the evaporator, achieving cab cooling. Operating Conditions: The A / C cooling switch is on, the knob is set to cooling mode, and the maximum battery pack temperature is ≤35°C. Execution: Refrigerant circuit three-way valves 2-3 are connected, the SOV is closed, the opening of electronic expansion valve EXV1 is adjusted based on the refrigerant superheat at the evaporator, EXV2 and 3 are closed, and the fan and compressor are turned on.

[0060] 5. Single Battery Cooling Mode: When the cab has no cooling or heating requirements and the battery temperature is too high and needs cooling, the high-temperature, high-pressure refrigerant releases heat through the condenser, passes through the electronic expansion valve EXV2, and is converted to a low-temperature, low-pressure state. It then passes through the chiller to exchange heat with the battery pack circuit coolant, absorbing heat from the battery pack circuit and achieving a cooling effect on the battery pack. Operating conditions: The air conditioning cooling switch is off, the knob is not in the cooling position, and the maximum battery pack temperature is >35°C. Execution: Refrigerant circuit three-way valves 2-3 are connected, battery pack circuit three-way valves 1-3 are connected, four-way valves 1-2 are connected, the SOV is closed, the opening of the electronic expansion valve EXV2 is adjusted according to the superheat of the refrigerant at the chiller, EXV1 and 3 are closed, and the fan, compressor, and water pump 2 are turned on.

[0061] 6. Cabin & Battery Pack Cooling Mode: When both the cab and battery pack require cooling, the high-temperature, high-pressure refrigerant releases heat through the condenser, then passes through electronic expansion valves EXV1 and 2 to a low-temperature, low-pressure state. It then flows through the chiller and evaporator, respectively, to cool the battery pack and cab. Operating Conditions: The air conditioner is on, the control knob is set to cooling mode, and the maximum battery pack temperature is >35°C. Execution: Refrigerant circuit three-way valves 2-3 are connected, battery pack circuit three-way valves 1-3 are connected, four-way valves 1-2 are connected, the SOV is closed, the opening of electronic expansion valve EXV1 is adjusted based on the refrigerant superheat at the evaporator, and the opening of electronic expansion valve EXV2 is adjusted based on the refrigerant superheat at the chiller. EXV3 is closed, and the fan, compressor, and water pump 2 are turned on.

[0062] 7. Single Cab Heating (PTC) Mode: The cab needs to be heated, but the battery pack does not need to be cooled or heated. When the ambient temperature is too low, the compressor is difficult to start, and the PTC needs to be turned on to assist in heating the coolant. The heated coolant passes through the indoor heat exchanger to heat the air in the cab, achieving the cab heating effect. Working conditions: Water temperature < 0°C and ambient temperature < -10°C. Execution: The three-way valve 2-3 of the battery pack circuit is connected, the four-way valve 1-2 is connected, and the W-PTC and water pump 2 are turned on.

[0063] 8. Single Cab Heating (Heat Pump) Mode: When the cab requires heating but the battery pack does not require cooling or heating, and the water temperature differs significantly from the ambient temperature, the fan must be turned on to draw heat from the outside through the condenser to assist the compressor in normal operation, allowing the compressor to start quickly and the refrigerant circuit temperature to rise rapidly, thereby providing heat to the coolant through LCC1. Operating conditions: 0°C < water temperature < 25°C and water temperature - ambient temperature < 5°C. Execution: Four-way valves 1-2 are connected, refrigerant circuit three-way valves 1-2 are connected, indoor heat exchanger circuit three-way valves 2-3 are connected, the solenoid valve is opened, the electronic expansion valve opening is adjusted based on the refrigerant superheat at LCC1, EXVs 1 and 2 are closed, and the compressor, fan, and water pump 2 are turned on.

[0064] 9. Single Cab Heating (Heat Pump) Mode: When the cab requires heating but the battery pack does not require cooling or heating, and the water temperature differs significantly from the ambient temperature, the fan must be turned on to draw heat from the outside through the condenser to assist the compressor in normal operation, allowing the compressor to start quickly and the refrigerant circuit temperature to rise rapidly, thereby providing heat to the coolant through LCC1. Operating conditions: 0°C < water temperature < 25°C and water temperature - ambient temperature < 5°C. Execution: Four-way valves 1-2 are connected, refrigerant circuit three-way valves 1-2 are connected, indoor heat exchanger circuit three-way valves 2-3 are connected, the solenoid valve is opened, the electronic expansion valve opening is adjusted based on the refrigerant superheat at LCC1, EXVs 1 and 2 are closed, and the compressor, fan, and water pump 2 are turned on.

[0065] 10. Single cab heating (heat pump + waste heat recovery) mode 1: The cab has a heating demand, but the battery pack has no cooling or heating demand. When the ambient temperature is too low, or the water temperature in the motor control circuit is high enough, the efficiency of absorbing heat from the outside through the condenser is too low, so the fan is turned off and the heat from the motor control circuit is exchanged to the refrigerant circuit through LCC2 for use in starting the compressor. Working conditions: When the water temperature in the motor control circuit is 25°C ≤ 30°C. Execution: Four-way valves 1-2 and 3-4 are connected, three-way valves 1-2 in the motor control circuit are connected, three-way valves 1-2 in the refrigerant circuit are connected, three-way valves 2-3 in the indoor heat exchanger circuit are connected, the solenoid valve is opened, the opening of the electronic expansion valve is adjusted according to the refrigerant superheat at the LCC, EXV1 and 2 are closed, and the compressor and water pumps 1 and 2 are started.

[0066] 11. Single Cab Heating (Heat Pump + Waste Heat Recovery) Mode 2: When the cab requires heating, the battery pack requires no cooling or heating, and there is a certain temperature difference between the water temperature and the ambient temperature, and the ambient temperature is sufficient, the fan is activated, drawing heat from the ambient air to the refrigerant circuit via the condenser. Simultaneously, the coolant in the motor control circuit transfers heat to the refrigerant circuit via LCC2, supplying heat to the compressor for startup. Operating conditions: 0 < water temperature < 25°C, water temperature minus ambient temperature ≥ 5°C, and ambient temperature < -10°C. Execution: Four-way valves 1-2 and 3-4 are connected, three-way valves 1-2 in the motor control circuit are connected, three-way valves 1-2 in the refrigerant circuit are connected, and three-way valves 2-3 in the indoor heat exchanger circuit are connected. The solenoid valve opens, and the electronic expansion valve adjusts its opening based on the refrigerant superheat at the LCC. EXVs 1 and 2 close, and the compressor, fan, and water pumps 1 and 2 start.

[0067] 12. Single Cab Heating (Heat Pump + Cooling) Mode: The cab requires heating, the battery pack requires no cooling or heating, and there is a certain temperature difference between the water temperature and the ambient temperature. If the water temperature is too high, in addition to transferring some of the excess heat generated by the motor and electronic control circuit to the refrigerant circuit via LCC2, the radiator must be activated to dissipate heat from the motor and electronic control circuit coolant to prevent excessive temperatures from affecting the normal operation of the motor and electronic control. Operating Conditions: 0 < water temperature < 25°C, water temperature - ambient temperature ≥ 5°C, and ambient temperature > -10°C. Execution: Four-way valves 1-2 and 3-4 are connected, three-way valves 2-3 in the motor and electronic control circuit are connected, three-way valves 1-2 in the refrigerant circuit are connected, three-way valves 2-3 in the indoor heat exchanger circuit are connected, the solenoid valve opens, the electronic expansion valve opening is adjusted based on the refrigerant superheat at the LCC, EXVs 1 and 2 are closed, and the compressor, fan, and water pumps 1 and 2 are activated.

[0068] 13. Single cab heating (waste heat recovery) mode: The cab needs to be heated, but the battery pack does not need to be cooled or heated. At this time, if the water temperature in the motor electronic control circuit is high enough, the coolant temperature in the motor electronic control circuit alone can be used to heat the cab. At this time, switch the four-way valve to the large circulation mode, connect all water lines, and pass the coolant temperature directly to the cab. The compressor is turned off, saving energy and increasing the vehicle's range. Working conditions: When the water temperature is ≥30°C. Execution action: Four-way valves 1-4 and 2-3 are connected, three-way valves 1-2 in the motor electronic control circuit are connected, indoor heat exchanger circuit 2-3 is connected, and water pumps 1 and 2 are turned on.

[0069] 14. Single Battery Heating (PTC) Mode: When the battery requires heating but the cab does not require cooling or heating, and the water temperature and external ambient temperature are too low, preventing the compressor from starting, the W-PTC is activated, serving as the sole heat source to heat the battery pack circuit coolant. This heat is then passed directly to the liquid cooling plate, exchanging heat with the battery pack to achieve the purpose of heating the battery pack. Operating Conditions: When the water temperature is <-5°C and the ambient temperature is <-10°C. Execution: Four-way valves 1-2 are connected, three-way valves 1-3 in the battery pack circuit are connected, and the W-PTC and water pump 2 are activated.

[0070] 15. Single battery heating (heat pump + PTC) mode: The battery has a heating demand, but the cab has no cooling or heating demand. When the external ambient temperature is suitable, the fan can be turned on to absorb heat from the outside through the condenser to ensure normal startup of the compressor. When the water temperature is low, the W-PTC is turned on for auxiliary heating, and the heat is transferred to the battery pack through the liquid cooling plate. Working conditions: -5℃≤water temperature<0℃ and ambient temperature>-10℃. Execution action: Four-way valve 1-2 is connected, refrigerant circuit three-way valve 1-2 is connected, battery pack circuit three-way valve 1-3 is connected, the solenoid valve is opened, the opening of the electronic expansion valve is adjusted according to the superheat of the refrigerant at the LCC, EXV1 and 2 are closed, and the compressor, W-PTC, fan, and water pump 2 are turned on.

[0071] 16. Single Battery Heating (Heat Pump) Mode: When the battery requires heating but the cab does not require cooling or heating, and the water temperature is sufficient and the temperature difference between the water temperature and the external ambient temperature is small, the heat generated by the heat pump alone can meet the battery pack heating needs. The high-temperature, high-pressure refrigerant exchanges heat with the battery pack circuit coolant through LCC1. Operating conditions: 0°C < water temperature < 25°C and water temperature - ambient temperature < 5°C. Execution: Four-way valves 1-2 are connected, the refrigerant circuit three-way valves 1-2 are connected, the battery pack circuit three-way valves 1-3 are connected, the solenoid valve opens, the electronic expansion valve opening is adjusted based on the refrigerant superheat at the LCC, EXVs 1 and 2 are closed, and the compressor, fan, and water pump 2 are turned on.

[0072] 17. Single Battery Heating (Heat Pump + Waste Heat Recovery) Mode 1: When the battery requires heating but the cabin does not require cooling or heating, the ambient temperature is suitable, and the motor control circuit water temperature is high, the refrigerant circuit absorbs heat from the motor control circuit and the ambient environment through LCC2 and the condenser, respectively, allowing the compressor to start normally. The high-temperature, high-pressure refrigerant then exchanges heat with the battery pack circuit coolant through LCC1, heating the battery pack. Operating conditions: 0°C < motor control circuit water temperature < 25°C, water temperature minus ambient temperature ≥ 5°C, and ambient temperature > -10°C. Execution: Four-way valves 1-2 and 3-4 are connected, three-way valves 1-2 of the motor control circuit are connected, three-way valves 1-3 of the battery pack circuit are connected, and three-way valves 1-2 of the refrigerant circuit are connected. The solenoid valve opens, and the electronic expansion valve opening is adjusted based on the refrigerant superheat at the LCC. EXVs 1 and 2 are closed, and the compressor, fan, and water pumps 1 and 2 are turned on.

[0073] 18. Single Battery Heating (Heat Pump + Waste Heat Recovery) Mode 2: When the battery requires heating but the cab does not require cooling or heating, the external ambient temperature is low, and the temperature difference between the motor control circuit water temperature and the external ambient temperature is large, the fan will not start. The refrigerant circuit's efficiency in absorbing heat from the outside through the condenser is too low. At this time, only the waste heat generated by the motor control circuit is transferred to the refrigerant circuit through LCC2, supplying it to the compressor for startup. Operating conditions: 0°C < motor control circuit water temperature < 25°C, water temperature minus ambient temperature ≥ 5°C, and ambient temperature < -10°C. Execution: Four-way valves 1-2 and 3-4 are connected, three-way valves 1-2 of the motor control circuit are connected, three-way valves 1-3 of the battery pack circuit are connected, and three-way valves 1-2 of the refrigerant circuit are connected. The solenoid valve opens, and the opening of the electronic expansion valve is adjusted according to the refrigerant superheat at the LCC. EXVs 1 and 2 are closed, and the compressor and water pumps 1 and 2 start.

[0074] 19. Single Battery Heating (Motor Waste Heat) Mode: When the battery requires heating but the cab does not require cooling or heating, and the motor control circuit water temperature is high, the waste heat generated by the motor control circuit is sufficient to heat the battery pack. At this time, the four-way valve connects the main circuit, transferring the motor control circuit water temperature to the battery pack circuit to achieve battery heating. Operating Condition: When the water temperature is 25°C ≤ < 35°C. Execution: Connect four-way valves 1-4 and 2-3, connect three-way valves 1-2 in the motor control circuit, connect three-way valves 1-3 in the battery pack circuit, and start water pumps 1 and 2.

[0075] 20. Single Battery Heating (Motor Waste Heat + Cooling) Mode: When the battery requires heating but the cab does not require cooling or heating, and the water temperature in the motor control circuit is too high, the circuit's heat not only meets the battery pack's heating needs, but also creates excess heat that needs to be discharged to the outside environment through the radiator to ensure normal operation of the motor control circuit. Operating Condition: When the water temperature is ≥35°C. Execution: Connect four-way valves 1-4 and 2-3, connect three-way valves 2-3 in the motor control circuit, connect three-way valves 1-3 in the battery pack circuit, and start fans and water pumps 1 and 2.

[0076] 21. Cabin & Battery Heating (PTC) Mode: Both the cab and the battery require heating. When the water temperature is low and the external ambient temperature is low, the efficiency of absorbing heat from the outside through the condenser is too low to meet the compressor startup conditions. Therefore, only the W-PTC is activated as the sole heat source to heat the water circuit, which is then passed to the liquid cooling plate and indoor heat exchanger respectively. Operating conditions: When the water temperature is less than 0°C and the ambient temperature is less than -10°C. Execution: Four-way valves 1 and 2 are connected, the three-way valves of the battery pack and indoor heat exchanger water circuits are fully opened, and the W-PTC and water pump 2 are activated.

[0077] 22. Cab & Battery Heating (Heat Pump + PTC) Mode: When both the cab and battery require heating and the water temperature is low and the external environment is suitable, the fan is turned on, and the refrigerant circuit absorbs heat from the external environment through the condenser. At the same time, the W-PTC is turned on to assist in heating the water temperature, allowing the compressor to start normally. The high-temperature and high-pressure refrigerant is exchanged with the water circuit through LCC1 and supplied to the liquid cooling plate and indoor heat exchanger. Operating conditions: Water temperature <0°C and ambient temperature >-10°C. Execution: Four-way valves 1-2 are connected, the three-way valves of the battery pack and indoor heat exchanger water circuits are fully opened, the refrigerant circuit three-way valves 1-2 are connected, the solenoid valve is opened, the opening of the electronic expansion valve is adjusted according to the refrigerant superheat at the LCC, and the W-PTC, fan, and water pump 2 are turned on.

[0078] 23. Cab & Battery Heating (Heat Pump) Mode: When both the cab and the battery require heating, and the water temperature is sufficient and the temperature difference between the water temperature and the external ambient temperature is small, the heat generated by the compressor alone can meet the heating needs of the cab and battery pack. The high-temperature and high-pressure refrigerant exchanges heat through LCC1 and the water circuit, and then passes to the liquid cooling plate and the indoor heat exchanger respectively. Working conditions: When the water temperature is 0℃ < 25℃ and the water temperature - the ambient temperature is less than 5℃. Execution: The four-way valve 1-2 is connected, the three-way valve of the battery pack and indoor heat exchanger water circuit is fully opened, the three-way valve 1-2 of the refrigerant circuit is connected, the solenoid valve is opened, the opening of the electronic expansion valve is adjusted according to the superheat of the refrigerant at the LCC, and the fan and water pump 2 are turned on.

[0079] 24. Cabin & Battery Heating (Heat Pump + Waste Heat Recovery) Mode 1: When both the cab and battery require heating, the ambient temperature is suitable, and the motor control circuit water temperature is high, the refrigerant circuit absorbs heat from the motor control circuit and the ambient environment through LCC2 and the condenser, respectively, allowing the compressor to start normally. The high-temperature, high-pressure refrigerant then exchanges heat with the coolant through LCC1, passing to the liquid cooling plate and indoor heat exchanger, respectively. Operating conditions: 0°C < motor control circuit water temperature < 25°C, water temperature minus ambient temperature ≥ 5°C, and ambient temperature > -10°C. Execution: Four-way valves 1-2 and 3-4 are connected, the three-way valve of the motor control circuit is fully opened, the three-way valves 1-2 of the refrigerant circuit are connected, the three-way valves 2-3 of the indoor heat exchanger circuit are connected, the solenoid valve is opened, the opening of the electronic expansion valve is adjusted based on the refrigerant superheat at the LCC, EXVs 1 and 2 are closed, and the compressor, fan, and water pumps 1 and 2 are started.

[0080] 25. Cabin & Battery Heating (Heat Pump + Waste Heat Recovery) Mode 2: When both the cab and battery require heating, and the external ambient temperature is low and the difference between the motor electronic control circuit water temperature and the external ambient temperature is large, the fan will no longer start. The refrigerant circuit's efficiency in absorbing heat from the outside through the condenser is too low. At this time, only the waste heat generated by the motor electronic control circuit is transferred to the refrigerant circuit through LCC2 and supplied to the compressor for startup. Operating conditions: 0℃ < motor electronic control circuit water temperature < 25℃ and water temperature - ambient temperature ≥ 5℃ and ambient temperature < -10℃. Execution: Four-way valves 1-2 and 3-4 are connected, the three-way valve of the motor electronic control circuit is fully opened, the three-way valves 1-3 of the battery pack circuit are connected, the three-way valves 1-2 of the refrigerant circuit are connected, the solenoid valve is opened, the opening of the electronic expansion valve is adjusted according to the refrigerant superheat at the LCC, EXV1 and 2 are closed, and the compressor and water pumps 1 and 2 are started.

[0081] 26. Cab & Battery Heating (Waste Heat Recovery) Mode: When both the cab and the battery require heating, and the motor control circuit water temperature is high, the waste heat generated by the motor control circuit is sufficient to heat the battery pack and the cab. At this time, the four-way valve connects the large loop, transferring the motor control circuit water temperature to the battery pack and the indoor heat exchanger circuit, thereby heating the battery and cab. Operating Conditions: When the water temperature is 25°C ≤ < 35°C. Execution: Connect four-way valves 1-4 and 2-3, connect three-way valves 1-2 in the motor control circuit, fully open the three-way valves in the battery pack and indoor heat exchanger circuits, and start water pumps 1 and 2.

[0082] 27. Cab & Battery Heating (Waste Heat Recovery + Heat Dissipation) Mode: Both the cab and the battery require heating. When the water temperature in the motor control circuit is too high, the circuit's heat not only meets the battery pack's heating needs, but also creates excess heat that needs to be discharged to the outside environment through the radiator to ensure normal operation of the motor control circuit. Operating Condition: When the water temperature is ≥35°C. Execution: Connect four-way valves 1-4 and 2-3, connect three-way valves 2-3 in the motor control circuit, fully open the three-way valve in the battery pack circuit, and start the fan and water pumps 1 and 2.

[0083] 28. Outdoor Condenser Defrost Mode: When frost forms on the outdoor condenser surface, the refrigerant flow is redirected, switching to cooling mode, shutting down the fan, and utilizing the high-temperature refrigerant for defrosting. Operating Conditions: Ambient temperature > 4°C and 25°C above the saturation temperature corresponding to the low pressure for 5 minutes, or for up to 30 minutes while the heat pump is on. Execution: Refrigerant circuit three-way valves 2-3 are connected, the opening of electronic expansion valve EXV1 is adjusted based on the refrigerant subcooling at the evaporator, EXVs 2 and 3 are closed, and the compressor and fan are turned on.

[0084] Beneficial effects:

[0085] 1. Use an indirect heat pump. In winter, when the ambient heating temperature is low, the compressor of a direct heat pump may not start. An indirect heat pump transfers heat through coolant, exchanging heat not only with the battery pack but also with the cabin air, effectively controlling and distributing heat. This indirect heat pump can more fully utilize ambient heat sources, effectively conserving energy and reducing operating costs.

[0086] Second, a waste heat recovery function has been added to the existing heat pump system. This fully utilizes the waste heat generated by the motor and electronic control during operation, exchanging it with the refrigerant circuit through a water-cooled condenser. This effectively improves the heat pump system's difficulty starting in low-temperature environments, reduces the power used by the PTC, lowers the vehicle's energy consumption, and increases its range.

[0087] Third, through integrated and optimized pipeline flow paths, over twenty different operating conditions can be achieved, meeting the needs of various driving environments and providing cooling and heating for the battery pack and cockpit. Furthermore, the integrated system takes up less space, facilitating installation and maintenance, and reducing system costs.

[0088] The above disclosure is merely a preferred embodiment of an integrated thermal management system for a pure electric commercial vehicle based on an indirect heat pump according to the present invention. This is certainly not intended to limit the scope of the present invention. A person skilled in the art will understand that any equivalent changes made by implementing all or part of the processes of the above embodiment in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. An integrated thermal management system for a pure electric commercial vehicle based on an indirect heat pump, characterized by: Including expansion tank 1, waste heat circuit, refrigerant circuit, battery pack and coolant circuit; The waste heat circuit is connected to the expansion water tank, the refrigerant circuit is connected to the waste heat circuit, the battery pack is connected to the coolant circuit, the coolant circuit is connected to the refrigerant circuit, and is connected to the waste heat circuit; The waste heat circuit includes a water pump 1, a temperature sensor 1, an electronic control, a motor, a three-way valve 1, a water-cooled condenser 2 and a four-way valve 1, wherein the water pump 1, the temperature sensor 1, the electronic control, the motor, the three-way valve 1, the water-cooled condenser 2 and the four-way valve 1 are connected in sequence; The refrigerant circuit includes a compressor, a second three-way valve, a first water-cooled condenser, a first temperature and pressure sensor, a second temperature and pressure sensor, a third temperature and pressure sensor, a condenser, a gas-liquid separator, a solenoid valve and an electronic expansion valve, wherein the compressor, the second three-way valve, the first water-cooled condenser, the second temperature and pressure sensor, the electronic expansion valve, the condenser, the third temperature and pressure sensor, the solenoid valve, the gas-liquid separator and the first temperature and pressure sensor are connected in sequence; The coolant circuit includes water pump 2, expansion water tank 2, three-way valve 3, heater, liquid cooling plate, indoor heat exchanger, temperature sensor 2, temperature sensor 3 and temperature sensor 4; the expansion water tank 2, the water pump 2, the heater, the three-way valve 3, the indoor heat exchanger and the temperature sensor 4 are connected in sequence, and the temperature sensor 2, the liquid cooling plate and the temperature sensor 3 are connected in sequence.

2. The integrated thermal management system for pure electric commercial vehicles based on an indirect heat pump according to claim 1, characterized in that: The integrated thermal management system for pure electric commercial vehicles based on an indirect heat pump further includes an evaporator, which is connected to the refrigerant circuit.

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