Pure electric commercial vehicle integrated heat management system based on indirect heat pump

Abstract

The invention relates to the technical field of heat management, in particular to a pure electric commercial vehicle integrated heat management system based on an indirect heat pump, which comprises an expansion water tank I, a waste heat loop, a refrigerant loop, a battery pack and a cooling liquid loop, a first expansion water tank, a waste heat loop, a refrigerant loop, a battery pack and a cooling liquid loop are adopted, and when the heating environment temperature is low in winter, a direct type heat pump compressor may not be started. Heat is transmitted through the cooling liquid, heat exchange with the battery pack can be achieved, heat exchange with air in a cab can also be achieved, and control and distribution of the heat can be well achieved. The indirect heat pump can more fully utilize an environmental heat source, more effectively save energy and reduce the operation cost. Therefore, the problem that a traditional heat pump system is difficult to start in winter is solved.

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] The integration of thermal management systems in most new energy commercial vehicles is not high. Usually, the battery pack circuit and the air conditioning circuit are connected in parallel through a heat exchanger, and the motor electronic control cooling circuit is an independent circuit. The system has too many components, which occupies a large space in the cabin. In addition, the heat of the motor electronic control circuit is discharged outside the vehicle and is not fully recycled. The overall thermal management efficiency is low, and the vehicle's cruising range is greatly affected.

[0003] At present, some new energy commercial vehicles use direct heat pumps, that is, the refrigerant circuit is directly connected to the evaporator or condenser in the cab to achieve the purpose of cooling or heating. However, the start-up conditions of direct heat pumps in low temperature environments are more stringent, and the heating effect of the heat pump will be significantly reduced when the external ambient temperature is low. Summary of the invention

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

[0005] To achieve the above-mentioned object, 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 discloses an integrated thermal management system for a pure electric commercial vehicle 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. Thereby solving the problem that the traditional heat pump system is 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 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.

[0013] Figure 1 It 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 cooling mode.

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

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

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

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

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

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

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

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

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

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

[0027] Fig.15 It is a schematic diagram of the single battery heating (PTC) mode.

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

[0029] Fig.17 It is a schematic diagram of the single battery heating (heat pump) mode.

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

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

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

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

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

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

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

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

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

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

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

[0041] Fig.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] 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.

[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 uses an expansion water tank 28, a waste heat circuit, a refrigerant circuit, a battery pack 29 and a coolant circuit. When the heating environment temperature is low in winter, the direct heat pump compressor may not be able to start. The present invention transmits heat through the coolant, which can not only exchange heat with the battery pack 29, but also with the air in the cab, and can better achieve heat control and distribution. The indirect heat pump can make more full use of the environmental heat source, save energy more effectively, and reduce operating costs. This solves the problem of the difficulty of starting the traditional heat pump system in winter.

[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, when the vehicle is running, the motor 4 electronic control 3 will generate a large amount of heat, 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, raising its temperature and the pressure is sufficient to meet the normal start of the compressor 8. The temperature of the coolant in the motor 4 electronic control 3 circuit is transferred to the refrigerant circuit, which 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 1 are connected in sequence.

[0050] In this embodiment, after the high-temperature and high-pressure refrigerant is discharged from the outlet of the compressor 8, it passes through the three-way valve 1-2 channel and enters the LCC1 to exchange heat with the coolant circuit. At this time, the coolant temperature is significantly lower than the refrigerant temperature, so the heat is transferred from the refrigerant to the coolant circuit. The refrigerant coming out of the LCC1 is throttled by the electronic expansion valve 17 and becomes a low-temperature and low-pressure refrigerant state. It absorbs heat from the outside through the condenser 14 and the fan. After the temperature is increased, the refrigerant passes through the gas-liquid separator 15 and enters the inlet of the compressor 8 again to complete the circulation of 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 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 external ambient temperature is suitable, the compressor 8 can work normally. After the coolant circuit absorbs the heat transferred from the high-temperature and high-pressure refrigerant at LCC1, it is diverted through the 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 the expansion water tank to complete the coolant circuit cycle. When the external ambient temperature is too low, the compressor 8 is difficult to start. At this time, the compressor 8 can complete the normal start-up by using the waste heat recovery function to increase the refrigerant inlet pressure. Or use a W-PTC thermistor to directly heat 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, and the evaporator 27 is connected to the refrigerant circuit.

[0054] In this embodiment, the refrigerant expands and vaporizes in the evaporator 27 to absorb heat, and the cold 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 to 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 in 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 in heating conditions; the radiator is used for the coolant in the radiator to blow out the heat 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 The 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 refrigeration 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, using 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 waste heat recovery and heat dissipation of the motor; the solenoid valve (Sov) is used to switch the 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 indicator; 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 Chiller, which are used to calculate the superheat degree of the refrigerant at the outlet of 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: The battery temperature difference is too large. To ensure the normal operation of the battery, the temperature difference of all cells must be kept small. At this time, no heat exchanger is turned on. Only water pump 2 is turned on according to demand to circulate the coolant to reduce the temperature difference between the cells. Working conditions: battery maximum temperature - battery minimum temperature ≥ 8°C. Execution action: four-way valve 1-2 is connected, water pump 2 is turned on, and battery pack circuit three-way valve 1-3 is connected.

[0057] 2. Motor electronic control cooling mode: When the motor electronic control temperature is too high, the motor circuit water pump is turned on, the fan is turned on, and the motor heat is taken away by the coolant circulation, and discharged to the outside through the radiator on the motor circuit. Working conditions: In charging mode or idling condition, when the motor electronic control temperature is ≥40℃. Execution action: Four-way valve 3-4 is connected, water pump 1 is turned on, and three-way valve 2-3 of the motor electronic control circuit is connected.

[0058] 3. Battery cooling mode: The battery pack temperature is too high, the four-way valve connects the motor electronic control circuit and the battery pack circuit, both water pumps are turned on, the coolant circuit completes the large cycle, and the heat of the battery pack is discharged to the outside through the radiator. Working conditions: In charging mode or idling conditions, the battery pack temperature is ≥40°C and the ambient temperature is ≤30°C. Execution action: Four-way valves 2-3 and 1-4 are connected, the three-way valve 2-3 of the motor electronic control circuit is connected, the three-way valve 1-3 of the battery pack circuit is connected, water pumps 1 and 2 are turned on, and the fan is turned on.

[0059] 4. Single cab cooling mode: The cab has cooling demand, but the battery pack has no cooling or heating demand. The high-temperature and high-pressure refrigerant releases heat through the condenser, changes to a low-temperature and low-pressure state through the electronic expansion valve EXV1, and absorbs heat through the evaporator to achieve the effect of cooling the cab. Working conditions: The air conditioning refrigeration switch is turned on and the knob is turned to the cooling mode and the maximum temperature of the battery pack is ≤35°C. Execution action: The three-way valves 2-3 of the refrigerant circuit are connected, SOV is closed, the opening of the electronic expansion valve EXV1 is adjusted according to the superheat of the refrigerant at the evaporator, EXV2 and 3 are closed, and the fan and compressor are turned on.

[0060] 5. Single battery cooling mode: When there is no cooling or heating 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 condenser, changes to a low-temperature and low-pressure state through the electronic expansion valve EXV2, exchanges heat with the battery pack circuit coolant through the Chiller, absorbs heat from the battery pack circuit, and achieves a cooling effect for the battery pack. Working conditions: The air conditioning refrigeration switch is turned off and the knob is not in the cooling position and the maximum temperature of the battery pack is greater than 35°C. Execution: The three-way valves 2-3 of the refrigerant circuit are connected, the three-way valves 1-3 of the battery pack circuit are connected, the 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. Cab & Battery Pack Cooling Mode: When the cab and battery pack need to be cooled at the same time, the high-temperature and high-pressure refrigerant releases heat through the condenser, passes through the electronic expansion valves EXV1 and 2 to become a low-temperature and low-pressure state, passes through the Chiller and evaporator respectively, and cools the battery pack and the cab. Working conditions: The air conditioner switch is turned on and the knob is turned to the cooling mode and the maximum temperature of the battery pack is greater than 35°C. Execution action: The three-way valves 2-3 of the refrigerant circuit are connected, the three-way valves 1-3 of the battery pack circuit are connected, the four-way valves 1-2 are connected, the SOV is closed, the opening of the electronic expansion valve EXV1 is adjusted according to the superheat of the refrigerant at the evaporator, the opening of the electronic expansion valve EXV2 is adjusted according to the superheat of the refrigerant 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 has a heating demand, but the battery pack has no cooling or heating demand. When the ambient temperature is too low, the compressor is difficult to start, and 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 to achieve the cab heating effect. Working conditions: water temperature <0°C and ambient temperature <-10°C. Execution action: The three-way valve 2-3 of the battery pack circuit is connected, the four-way valve 1-2 is connected, and W-PTC and water pump 2 are turned on.

[0063] 8. Single cab heating (heat pump) mode: The cab has a heating demand, but the battery pack has no cooling or heating demand. When the water temperature is significantly different from the ambient temperature, the fan needs to be turned on to absorb heat from the outside through the condenser to assist the compressor in normal operation, so that the compressor starts quickly and the refrigerant circuit temperature rises quickly, so as to achieve the purpose of supplying heat to the coolant through LCC1. Working conditions: 0℃<water temperature<25℃ and water temperature-ambient temperature<5℃. Execution action: Four-way valve 1-2 is connected, three-way valve 1-2 of the refrigerant circuit is connected, three-way valve 2-3 of the indoor heat exchanger 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 LCC1, EXV1 and 2 are closed, and the compressor, fan, and water pump 2 are turned on.

[0064] 9. Single cab heating (heat pump) mode: The cab has a heating demand, but the battery pack has no cooling or heating demand. When the water temperature is significantly different from the ambient temperature, the fan needs to be turned on to absorb heat from the outside through the condenser to assist the compressor in normal operation, so that the compressor starts quickly and the temperature of the refrigerant circuit rises quickly, so as to achieve the purpose of supplying heat to the coolant through LCC1. Working conditions: 0℃<water temperature<25℃ and water temperature-ambient temperature<5℃. Execution action: Four-way valve 1-2 is connected, three-way valve 1-2 of the refrigerant circuit is connected, three-way valve 2-3 of the indoor heat exchanger 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 LCC1, EXV1 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, and the battery pack has no cooling and heating demand. When the outside ambient temperature is too low, or the water temperature of the motor electronic control circuit is high enough, the efficiency of absorbing heat from the outside through the condenser is too low, and the fan is turned off. The heat of the motor electronic control circuit is exchanged to the refrigerant circuit through LCC2 for the compressor to start. Working conditions: 25℃≤motor electronic control circuit water temperature≤30℃. Execution action: Four-way valves 1-2 are connected, 3-4 are connected, the three-way valves 1-2 of the motor electronic control circuit are connected, 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, and 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 and water pumps 1 and 2 are turned on.

[0066] 11. Single cab heating (heat pump + waste heat recovery) mode 2: The cab has a heating demand, the battery pack has no cooling and heating demand, there is a certain temperature difference between the water temperature and the external ambient temperature, and when the external ambient temperature is sufficient, the fan can be turned on to absorb heat from the external environment to the refrigerant circuit through the condenser. At the same time, the coolant in the motor electronic control circuit transfers heat to the refrigerant circuit through LCC2 and supplies the compressor for startup. Working conditions: 0<water temperature<25℃ and water temperature-ambient temperature≥5℃ and ambient temperature<-10℃. Execution action: four-way valves 1-2 and 3-4 are connected, three-way valves 1-2 of the motor electronic control circuit are connected, three-way valves 1-2 of the refrigerant circuit are connected, 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 according to the superheat of the refrigerant at the LCC, EXV1 and 2 are closed, and the compressor, fan, and water pump 1 and 2 are turned on.

[0067] 12. Single cab heating (heat pump + cooling) mode: The cab has heating demand, the battery pack has no cooling and heating demand, there is a certain temperature difference between the water temperature and the external ambient temperature, and when the water temperature is too high, in addition to transferring part of the waste heat generated by the motor electronic control to the refrigerant circuit through LCC2, it is also necessary to open the radiator to dissipate the coolant of the motor electronic control circuit to prevent the high temperature from affecting the normal operation of the motor electronic control. Working conditions: 0 < water temperature < 25 ° C and water temperature - ambient temperature ≥ 5 ° C and ambient temperature > -10 ° C. Execution action: four-way valves 1-2 and 3-4 are connected, three-way valves 2-3 of the motor electronic control circuit are connected, three-way valves 1-2 of the refrigerant circuit are connected, 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 according to the superheat of the refrigerant at the LCC, EXV1 and 2 are closed, and the compressor, fan, and water pump 1 and 2 are turned on.

[0068] 13. Single cab heating (waste heat recovery) mode: The cab has a heating demand, the battery pack has no cooling and heating demand, and when the water temperature of the motor electronic control circuit is high enough, the coolant temperature of 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, connect all water circuits, and pass the coolant temperature directly to the cab. The compressor is turned off to save energy and increase the vehicle's cruising range. Working conditions: When the water temperature is ≥30°C. Execution action: Four-way valves 1-4 and 2-3 are connected, the three-way valve 1-2 of the motor electronic control circuit is connected, the indoor heat exchanger circuit 2-3 is connected, and water pumps 1 and 2 are turned on.

[0069] 14. Single battery heating (PTC) mode: The battery has a heating demand, but the cab has no cooling or heating demand. When the water temperature is too low and the external ambient temperature is too low, and the compressor cannot meet the starting conditions, turn on W-PTC to heat the battery pack circuit coolant as the only heat source, and directly connect it to the liquid cooling plate to exchange heat with the battery pack to achieve the purpose of heating the battery pack. Working conditions: When the water temperature is less than -5°C and the ambient temperature is less than -10°C. Execution action: Four-way valve 1-2 is connected, three-way valve 1-3 of the battery pack circuit is connected, and W-PTC and water pump 2 are turned on.

[0070] 15. Single battery heating (heat pump + PTC) mode: The battery has a heating demand, and 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 the normal start of the compressor. When the water temperature is low, turn on W-PTC 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: The battery has a heating demand, the cab has no cooling and heating demand, the water temperature is sufficient and the temperature difference between the water temperature and the external ambient temperature is not large, the heat generated by the heat pump alone can meet the battery pack heating demand, and the high-temperature and high-pressure refrigerant exchanges heat with the battery pack circuit coolant through LCC1. Working conditions: 0℃<water temperature<25℃ and water temperature-ambient temperature<5℃. Execution action: Four-way valve 1-2 is connected, the refrigerant circuit three-way valve 1-2 is connected, the 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 refrigerant superheat at the LCC, EXV1 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 has heating demand, the cab has no cooling and heating demand, the external ambient temperature is suitable and the water temperature of the motor electronic control circuit is high, the refrigerant circuit can absorb heat from the motor electronic control circuit and the external environment through LCC2 and the condenser respectively, so that the compressor can start normally, and then the high-temperature and high-pressure refrigerant is exchanged with the battery pack circuit coolant through LCC1 to achieve the purpose of heating the battery pack. Working conditions: 0℃<motor electronic control circuit water temperature<25℃ and water temperature-ambient temperature≥5℃ and ambient temperature>-10℃. Execution action: four-way valves 1-2, 3-4 are connected, three-way valves 1-2 of the motor electronic control circuit are connected, three-way valves 1-3 of the battery pack circuit are connected, 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 superheat of the refrigerant at the LCC, EXV1, 2 are closed, and the compressor, fan, and water pump 1, 2 are turned on.

[0073] 18. Single battery heating (heat pump + waste heat recovery) mode 2 The battery has a heating demand, the cab has no cooling and heating demand, the external ambient temperature is low and the temperature difference between the motor electronic control circuit water temperature and the external ambient temperature is large, the fan is no longer turned on, and the efficiency of the refrigerant circuit 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. Working conditions: 0℃<motor electronic control circuit water temperature<25℃ and water temperature-ambient temperature ≥5℃ and ambient temperature<-10℃. Execution action: four-way valves 1-2, 3-4 are connected, three-way valves 1-2 of the motor electronic control circuit are connected, three-way valves 1-3 of the battery pack circuit are connected, 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 superheat of the refrigerant at the LCC, EXV1, 2 are closed, and the compressor and water pumps 1, 2 are turned on.

[0074] 19. Single battery heating (motor waste heat) mode: The battery has heating demand, but the cab has no cooling or heating demand. When the water temperature of the motor electronic control circuit is high, the waste heat generated by the motor electronic control is sufficient to heat the battery pack. At this time, the four-way valve is connected to the large loop, and the water temperature of the motor electronic control circuit is transferred to the battery pack circuit to achieve the purpose of heating the battery. Working conditions: 25℃≤water temperature<35℃. Execution action: four-way valves 1-4 and 2-3 are connected, three-way valves 1-2 of the motor electronic control circuit are connected, three-way valves 1-3 of the battery pack circuit are connected, and water pumps 1 and 2 are turned on.

[0075] 20. Single battery heating (motor waste heat + heat dissipation) mode: The battery has a heating demand, the cab has no cooling and heating demand, and the water temperature of the motor electronic control circuit is too high. At this time, the heat of the circuit can not only meet the heating of the battery pack, but also have excess heat, which needs to be discharged to the outdoor environment through the radiator to ensure that the motor electronic control can work normally. Working conditions: When the water temperature is ≥35℃. Execution action: Four-way valves 1-4 and 2-3 are connected, the three-way valve 2-3 of the motor electronic control circuit is connected, the three-way valve 1-3 of the battery pack circuit is connected, and the fan and water pumps 1 and 2 are turned on.

[0076] 21. Cab & Battery Heating (PTC) Mode: Both the cab and the battery have heating requirements. 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 start-up conditions. Therefore, only W-PTC is turned on as the only heat source at this time to heat the water circuit and pass it to the liquid cooling plate and indoor heat exchanger respectively. Working conditions: When the water temperature is less than 0°C and the ambient temperature is less than -10°C. Execution action: The four-way valve 1-2 is connected, the three-way valve of the battery pack and the indoor heat exchanger water circuit is fully opened, and the W-PTC and water pump 2 are turned on.

[0077] 22. Cab & Battery Heating (Heat Pump + PTC) Mode: Both the cab and the battery need to be heated. When the water temperature is low and the external environment is suitable, turn on the fan, and the refrigerant circuit absorbs heat from the external environment through the condenser. At the same time, turn on the W-PTC to assist in heating the water temperature so that the compressor can 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 the indoor heat exchanger. Working conditions: water temperature <0°C and ambient temperature >-10°C. Execution action: Four-way valve 1-2 is connected, the three-way valve of the battery pack and the 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, and the opening of the electronic expansion valve is adjusted according to the superheat of the refrigerant at the LCC. W-PTC, fan, and water pump 2 are turned on.

[0078] 23. Cab & Battery Heating (Heat Pump) Mode: Both the cab and the battery have heating requirements. When the water temperature is sufficient and the temperature difference between the water temperature and the external ambient temperature is not large, the heat generated by the compressor alone can meet the heating requirements of the cab and the 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: 0℃<water temperature<25℃ and water temperature-ambient temperature<5℃. Execution action: 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, and the opening of the electronic expansion valve is adjusted according to the superheat of the refrigerant at the LCC. The fan and water pump 2 are turned on.

[0079] 24. Cab & Battery Heating (Heat Pump + Waste Heat Recovery) Mode 1: Both the cab and the battery have heating requirements. When the external ambient temperature is suitable and the water temperature of the motor electronic control circuit is high, the refrigerant circuit can absorb heat from the motor electronic control circuit and the external environment through LCC2 and the condenser respectively, so that the compressor can start normally, and then the high-temperature and high-pressure refrigerant is exchanged with the coolant through LCC1, and passed to the liquid cooling plate and the indoor heat exchanger respectively. Working conditions: 0℃<motor electronic control circuit water temperature<25℃ and water temperature-ambient temperature≥5℃ and ambient temperature>-10℃. Execution action: Four-way valves 1-2 are connected, 3-4 are connected, the three-way valve of the motor electronic control circuit is fully opened, the three-way valve 1-2 of the refrigerant circuit is connected, the three-way valve 2-3 of the indoor heat exchanger 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, EXV1 and 2 are closed, and the compressor, fan, and water pump 1 and 2 are turned on.

[0080] 25. Cab & Battery Heating (Heat Pump + Waste Heat Recovery) Mode 2: Both the cab and the battery have heating requirements. When the external ambient temperature is low and the temperature difference between the motor electronic control circuit water temperature and the external ambient temperature is large, the fan will no longer be turned on. The efficiency of the refrigerant circuit 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. Working conditions: 0℃<motor electronic control circuit water temperature<25℃ and water temperature-ambient temperature ≥5℃ and ambient temperature<-10℃. Execution action: 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, and 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 and water pumps 1 and 2 are turned on.

[0081] 26. Cab & Battery Heating (Waste Heat Recovery) Mode: Both the cab and the battery have heating requirements. When the water temperature of the motor electronic control circuit is high, the waste heat generated by the motor electronic control is sufficient to heat the battery pack and the cab. At this time, the four-way valve is connected to the large circulation, and the water temperature of the motor electronic control circuit is transferred to the battery pack and the indoor heat exchanger circuit to achieve the purpose of heating the battery and the cab. Working conditions: 25℃≤water temperature<35℃. Execution action: Four-way valves 1-4 and 2-3 are connected, the three-way valves 1-2 of the motor electronic control circuit are connected, the three-way valves of the battery pack and the indoor heat exchanger circuit are fully opened, and water pumps 1 and 2 are turned on.

[0082] 27. Cab & Battery Heating (Waste Heat Recovery + Heat Dissipation) Mode: Both the cab and the battery have heating requirements. When the water temperature of the motor electronic control circuit is too high, the heat of the circuit can not only meet the heating of the battery pack, but also has excess heat, which needs to be discharged to the outdoor environment through the radiator to ensure that the motor electronic control can work normally. Working conditions: When the water temperature is ≥35℃. Execution action: Four-way valves 1-4 and 2-3 are connected, the three-way valve 2-3 of the motor electronic control circuit is connected, the three-way valve of the battery pack circuit is fully opened, and the fan and water pumps 1 and 2 are turned on.

[0083] 28. Outdoor condenser defrosting mode: When frost forms on the surface of the outdoor condenser, the flow direction of the refrigerant is changed, the system switches to cooling mode, the fan is turned off, and high-temperature refrigerant is used to defrost. Working conditions: The ambient temperature is > 4°C and the ambient temperature is 25°C higher than the saturation temperature corresponding to the low pressure for 5 minutes or the heat pump is turned on for 30 minutes. Execution: The three-way valves 2-3 of the refrigerant circuit are connected, the opening of the electronic expansion valve EXV1 is adjusted according to the refrigerant supercooling at the evaporator, EXV2 and 3 are closed, and the compressor and fan are turned on.

[0084] Beneficial effects:

[0085] 1. Use an indirect heat pump. When the heating environment temperature is low in winter, the direct heat pump compressor may not start. The indirect heat pump transfers heat through the coolant, which can not only exchange heat with the battery pack, but also with the air in the cab, which can better control and distribute heat. The indirect heat pump can make better use of the environmental heat source, save energy more effectively, and reduce operating costs.

[0086] Second, in the existing heat pump system, a waste heat recovery function is added. The waste heat generated by the motor and electronic control during operation is fully utilized, and the waste heat is exchanged with the refrigerant circuit through the water-cooled condenser, which effectively improves the problem of the heat pump system being difficult to start in a low temperature environment, reduces the power used by the PTC, reduces the energy consumption of the entire vehicle, and increases the vehicle's cruising range.

[0087] 3. Through integrated optimization of pipeline flow channels, more than 20 different working conditions can be achieved to meet the cooling and heating of the battery pack and the cockpit in different environments during vehicle driving. At the same time, the integrated system has a small space occupancy rate, is more convenient for installation and maintenance, and saves the cost of system use.

[0088] The above disclosure is only a preferred embodiment of the integrated thermal management system for pure electric commercial vehicles based on an indirect 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 according to the claims of the present invention still fall 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 in that: It includes an expansion tank, 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, 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.

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 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. 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.

3. The integrated thermal management system for pure electric commercial vehicles based on an indirect heat pump according to claim 1, characterized in that: 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.

4. The integrated thermal management system for pure electric commercial vehicles based on an indirect heat pump according to claim 1, characterized in that: 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.

5. 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.

Images