Electric heavy truck thermal management system and method

Abstract

The invention discloses a thermal management system and method for an electric heavy truck. The thermal management system for the electric heavy truck comprises a heat exchange part, a switching valve, a refrigerant compressor and a containing part. The heat exchange part comprises an inner heat exchanger, an inner valve, an outer heat exchanger and a first expansion valve which are sequentially connected end to end; the switching valve is provided with two first ports and two second ports and can control the first ports to be independently communicated with or disconnected from the second ports, and the two second ports are connected into a connecting pipeline between the inner valve and the outer heat exchanger. The inlet end and the outlet end of the refrigerant compressor are respectively connected with the two first ports; the containing part is provided with a channel used for containing the power battery, and the channel is connected with a connecting pipeline between the switching valve and the inner valve and connected with a connecting pipeline between the first expansion valve and the inner heat exchanger. According to the scheme, cooling of the power battery and temperature adjustment of the driving cabin are integrated together, a driving device does not need to be independently arranged, system components are simplified, cooperation is improved, the occupied space is small, and integration is convenient to achieve.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal management of electric heavy-duty trucks, and in particular to a thermal management system and method for electric heavy-duty trucks. Background Art

[0002] Electric heavy-duty trucks offer significant advantages over traditional heavy-duty trucks in terms of emissions, driving experience, and operating costs. However, thermal runaway caused by the accumulation of waste heat from power batteries can lead to a decrease in battery capacity and range, increasing the risk of fire and explosion. Therefore, power battery cooling equipment is necessary.

[0003] Publication number CN111786055A discloses a new energy vehicle power battery cooling system, which includes at least two groups of cooling plates. A coolant piping system is distributed on the lower side of the cooling plates. The coolant piping system includes an inner cooling pipe distributed on the lower surface of the cooling plate, and an outer cooling pipe located outside the cooling plate. The outer cooling pipe and the inner cooling pipe are interconnected, wherein the outer cooling pipe is provided with a circulating water pump and a radiator. A heat exchanger is provided between the outer cooling pipes of two adjacent groups of cooling plates to balance the temperature difference between the two groups of cooling plates, thereby removing the heat of the battery through circulating water.

[0004] However, the above patent provides an independent cooling system for the battery, and uses an independently set circulating water pump to guide water circulation for cooling, so that the thermal management of the vehicle's cabin and battery are independent of each other, with low coordination and not conducive to integration. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned technical deficiencies and propose an electric heavy-duty truck thermal management system and method to solve the technical problem in the prior art of independently equipping the battery with a cooling system, guiding the water circulation for cooling through an independently arranged circulating water pump, so that the thermal management of the vehicle's passenger compartment and the battery are independent of each other, resulting in complex components of the vehicle's electric heavy-duty truck thermal management system, low collaboration, and large space occupation, which is not conducive to integration.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a thermal management system for an electric heavy truck, comprising: The heat exchange part includes an internal heat exchanger, an internal valve, an external heat exchanger and a first expansion valve connected end to end; a switching valve having two first ports and two second ports, and capable of controlling each first port to independently connect to and disconnect from each second port, wherein the two second ports are connected to the connecting pipeline between the inner valve and the outer heat exchanger; a refrigerant compressor, the inlet and outlet of which are respectively connected to the two first ports; and The accommodating portion has a channel for accommodating a power battery and can control the on-off of the channel. The channel connects the connecting pipeline between the switching valve and the inner valve, and connects the connecting pipeline between the first expansion valve and the inner heat exchanger.

[0007] In some embodiments, the accommodating portion includes a accommodating tube, a accommodating sleeve and a accommodating valve. One end of the accommodating tube is connected to the connecting pipeline between the switching valve and the internal valve, and the other end is connected to the connecting pipeline between the first expansion valve and the internal heat exchanger. The accommodating sleeve is arranged in the accommodating tube and is used to accommodate the power battery, and together with the internal cavity of the accommodating tube, it constitutes the channel. The accommodating valve is arranged in the accommodating tube.

[0008] In some embodiments, the accommodating tube has a first section located on a side of the accommodating sleeve close to the switching valve, and has a second section located on a side of the accommodating sleeve close to the first expansion valve, and the accommodating valve is provided in the first section; The electric heavy-duty truck thermal management system further includes a bypass pipe and a bypass valve. The bypass pipe is connected to the first section, and its connection point is located between the accommodating valve and the accommodating sleeve, and is connected to the connecting pipeline between the switching valve and the external heat exchanger. The bypass valve is provided on the bypass pipe. The electric heavy truck thermal management system further includes a first heater, which is disposed in the second section.

[0009] In some embodiments, the connection between the bypass pipe and the first section is a first connection; The accommodating portion further includes a first valve and a second valve. The first valve is provided in the first section and located between the first connection and the accommodating sleeve. The second valve is provided in the second section and located on a side of the first heater away from the accommodating sleeve.

[0010] In some embodiments, the connection point between the connecting pipe between the switching valve and the external heat exchanger and the bypass pipe is the second connection point; The heat exchange portion further includes an external valve, which is arranged between the second connection point and the external heat exchanger.

[0011] In some embodiments, the inlet end of the refrigerant compressor is sequentially connected to a filter dryer and a gas-liquid separator in a direction close to the switching valve.

[0012] In some embodiments, the thermal management system for an electric heavy truck further includes a heat pipe, a heat dissipation jacket, a coolant tank, a first heat exchange member, and a pump body. The heat pipe is connected end to end. The inner cavity of the heat dissipation jacket is used to accommodate the motor assembly and is connected to the heat pipe. The coolant tank is provided on the heat pipe. The first heat exchange member has a heat source flow channel and a heat absorption flow channel. The heat source flow channel is connected to the heat pipe. The pump body is provided on the heat pipe. The heat exchange part also includes a waste heat pipe and a waste heat valve. The waste heat pipe connects the connecting pipeline between the internal heat exchanger and the first expansion valve, connects the connecting pipeline between the external heat exchanger and the switching valve, and is connected to the heat absorption flow channel. The waste heat valve is arranged on the waste heat pipe.

[0013] In some embodiments, the thermal management system of the electric heavy truck also includes a cooling pipe, a second heat exchanger and two control valves. The cooling pipe has two access ends, both of which are connected to the heat dissipation pipe and are located on both sides of the first heat exchanger. The second heat exchanger has a flow channel connected to the cooling pipe. One of the two control valves is provided in the cooling pipe, and the other is provided in the heat dissipation pipe and is located between the access end and the first heat exchanger.

[0014] In some embodiments, the connection point between the connecting pipe between the switching valve and the external heat exchanger and the waste heat pipe is the third connection point, and the connection point between the connecting pipe between the internal heat exchanger and the first expansion valve and the waste heat pipe is the fourth connection point; The waste heat valve includes a third valve, a second expansion valve and a fourth valve. The third valve and the second expansion valve are arranged between the first heat exchange element and the third connection point, and the second expansion valve and the fourth valve are arranged between the first heat exchange element and the fourth connection point, and are arranged in sequence along the direction close to the fourth connection point.

[0015] In addition, the present invention further provides a thermal management method, which is applied to the thermal management system of an electric heavy truck as described above, and the thermal management method includes: obtaining an actual cabin temperature and a first preset cabin temperature range, obtaining an actual power battery temperature and a first preset power battery temperature range, and determining whether the actual cabin temperature meets the first preset cabin temperature range, and determining whether the actual power battery temperature meets the first preset power battery temperature range; If the actual temperature of the passenger cabin meets the first preset temperature range of the passenger cabin and the actual temperature of the power battery meets the first preset temperature range of the power battery, controlling the accommodating portion to disconnect the passage, controlling the inner valve and the first expansion valve to open, and controlling the switching valve to connect the inner valve to the outlet of the refrigerant compressor and to connect the external heat exchanger to the inlet of the refrigerant compressor; If the actual temperature of the power battery is greater than the first preset temperature range of the power battery, the accommodating portion is controlled to connect the channel, the first expansion valve is controlled to open, and the switching valve is controlled to connect the channel to the inlet end of the refrigerant compressor, and the external heat exchanger is connected to the outlet end of the refrigerant compressor.

[0016] Compared to the prior art, the electric heavy-duty truck thermal management system provided by the present invention utilizes an internal heat exchanger for cabin temperature control. Because the power battery is located within the channel of the housing, when the core temperature of the power battery is too high, the switching valve can be switched to connect the outlet of the refrigerant compressor to the external heat exchanger and the channel of the housing to the inlet of the refrigerant compressor. Simultaneously, the channel is controlled to be open, and the first expansion valve is controlled to open. At this point, the high-temperature, high-pressure gaseous refrigerant output from the refrigerant compressor outlet exchanges heat with the outside world at the external heat exchanger, condensing and releasing heat, converting to a high-temperature, high-pressure liquid refrigerant. This refrigerant then flows through the first expansion valve, decompressing into a low-temperature, low-pressure liquid refrigerant. The liquid then flows through the channel of the housing, where it vaporizes and absorbs heat from the power battery, thereby reducing the power battery temperature. Finally, it flows back through the inlet of the refrigerant compressor.

[0017] During this process, the internal valve can also be opened, allowing the low-temperature, low-pressure liquid refrigerant that has passed through the first expansion valve to partially flow to the internal heat exchanger, where it vaporizes and absorbs heat, thereby lowering the cabin temperature. Furthermore, by disconnecting the channel and adjusting the switching valve to redirect the refrigerant flow, cabin heating can be achieved, enabling three modes: power battery cooling, cabin cooling, and cabin heating. This solution integrates power battery cooling and cabin temperature control, eliminating the need for separate drive units, improving interoperability and facilitating integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic diagram of a thermal management system for an electric heavy truck provided by an embodiment of the present invention; Figure 2 yes Figure 1 Schematic diagram of the heat exchange portion, the accommodating portion and the refrigerant compressor; Figure 3 yes Figure 2 a schematic diagram of the middle accommodating portion; Figure 4 yes Figure 2 Schematic diagram of the middle bypass pipe and refrigerant compressor; Figure 5 Figure 1 Schematic diagram of the heat dissipation pipe and waste heat pipe; Figure 6 This is a flow chart of a thermal management method provided by one embodiment of the present invention.

[0019] Description of reference numerals: 1. Heat exchange unit; 11. Internal heat exchanger; 12. Internal valve; 13. External heat exchanger; 14. First expansion valve; 15. External valve; 16. Waste heat pipe; 161. Third connection; 162. Fourth connection; 17. Waste heat valve; 171. Third valve; 172. Second expansion valve; 173. Fourth valve; 2. Switching valve; 21. First port; 22. Second port; 3. Refrigerant compressor; 31. Inlet port; 32. Outlet port; 4. Accommodation unit; 41. Accommodation pipe; 411 , first section; 412, second section; 42, accommodating sleeve; 43, accommodating valve; 44, first valve; 45, second valve; 5, bypass pipe; 51, bypass valve; 52, first connection; 53, second connection; 6, first heater; 7, filter dryer; 8, heat dissipation pipe; 81, heat dissipation sleeve; 82, coolant tank; 83, first heat exchange element; 84, pump body; 85, cooling pipe; 86, second heat exchange element; 87, cooling control valve; 88, heat exchange control valve; 9, gas-liquid separator. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] In order to solve the technical problem that an independent cooling system is provided for the battery, and water circulation is guided for cooling by an independently arranged circulating water pump, so that the thermal management of the vehicle's cabin and battery are independent of each other, the coordination is low, and it is not conducive to integration, the present invention provides an electric heavy-duty truck thermal management system that integrates the cooling of the power battery and the temperature adjustment of the cabin. It does not require an independent drive device, simplifies system components, improves coordination, occupies less space, and is easy to integrate.

[0022] It should be noted that the electric heavy-duty truck thermal management system described in the present invention is used for but not limited to vehicles, etc. For the convenience of explanation, in the present invention, only the electric heavy-duty truck thermal management system is applied to vehicles as an example for explanation. The principles of the electric heavy-duty truck thermal management system applied to other types of equipment are essentially the same as those applied to vehicles, and will not be repeated here.

[0023] See also Figures 1 to 4 , Figures 1 to 4Schematic diagram of the structure of the thermal management system of an electric heavy-duty truck in one embodiment of the present invention, the thermal management system of the electric heavy-duty truck includes a heat exchange part 1, a switching valve 2, a refrigerant compressor 3 and a accommodating part 4; the heat exchange part 1 includes an internal heat exchanger 11, an internal valve 12, an external heat exchanger 13 and a first expansion valve 14 connected in sequence end to end; the switching valve 2 has two first ports 21 and two second ports 22, and can control each first port 21 to independently connect and disconnect each second port 22, and the two second ports 22 are connected to the connecting pipe between the internal valve 12 and the external heat exchanger 13; the refrigerant compressor 3, its inlet end 31 and the outlet end 32 are respectively connected to the two first ports 21; the accommodating part 4 has a channel for accommodating a power battery, and can control the opening and closing of the channel, the channel connects the connecting pipe between the switching valve 2 and the internal valve 12, and connects the connecting pipe between the first expansion valve 14 and the internal heat exchanger 11.

[0024] In the electric heavy-duty truck thermal management system provided by the present invention, an internal heat exchanger 11 is used to control the cabin temperature. Since the power battery is located in the channel of the accommodating portion 4, when the core temperature of the power battery is too high, the switching valve 2 can be switched to connect the outlet 32 ​​of the refrigerant compressor 3 to the external heat exchanger 13, and the channel of the accommodating portion 4 to the inlet 31 of the refrigerant compressor 3. Simultaneously, the channel is controlled to be open, and the first expansion valve 14 is controlled to be open. At this time, the high-temperature, high-pressure gaseous refrigerant output from the outlet 32 ​​of the refrigerant compressor 3 exchanges heat with the outside world at the external heat exchanger 13, condensing and releasing heat, and converting to a high-temperature, high-pressure liquid refrigerant. The refrigerant then flows through the first expansion valve 14, where it is decompressed to a low-temperature, low-pressure liquid refrigerant. The refrigerant then flows through the channel of the accommodating portion 4, where it vaporizes and absorbs heat from the power battery, thereby reducing the power battery temperature. The refrigerant finally flows back through the inlet 31 of the refrigerant compressor 3.

[0025] During this process, internal valve 12 can also be opened, allowing the low-temperature, low-pressure liquid refrigerant that has passed through first expansion valve 14 to partially flow to internal heat exchanger 11, where it vaporizes and absorbs heat, thereby lowering the cabin temperature. Furthermore, by disconnecting the channel and adjusting switching valve 2 to redirect the refrigerant flow, cabin heating can be achieved, thus enabling three modes: power battery cooling, cabin cooling, and cabin heating. This solution integrates power battery cooling with cabin temperature control, eliminating the need for separate drive units, improving interoperability, and facilitating integration.

[0026] It should be noted that in one embodiment, the switching valve 2 is configured as six sets of connection components, each set of connection components including a pipe and a valve mounted thereon, and the six pipe connections connect the components corresponding to the four ports in pairs. In another embodiment, the switching valve 2 is configured as two movable pipes, with valves mounted at each port, and the ports are connected through the movable pipes.

[0027] In another embodiment, the switching valve 2 is configured as a four-way valve. The specific structure and principle of the four-way valve are prior art and will not be described in detail herein. It should be understood that the outflow channel and the return channel of the switching valve 2 are isolated from each other.

[0028] In addition, it should be noted that the accommodating portion 4 can be configured in the form of a pipe and a valve, or in the form of a shell and a valve, or in other forms.

[0029] In one embodiment, the accommodating portion 4 includes an accommodating tube 41, an accommodating sleeve 42 and an accommodating valve 43. One end of the accommodating tube 41 is connected to the connecting pipeline between the switching valve 2 and the internal valve 12, and the other end is connected to the connecting pipeline between the first expansion valve 14 and the internal heat exchanger 11. The accommodating sleeve 42 is connected to the accommodating tube 41 and is used to accommodate the power battery. It forms a channel together with the internal cavity of the accommodating tube 41. The accommodating valve 43 is arranged in the accommodating tube 41.

[0030] In this embodiment, the power battery is placed within the housing 42. Low-temperature, low-pressure refrigerant flowing through the housing 42 dissipates heat from the power battery, improving heat dissipation capabilities. It should be noted that in this embodiment, the housing 42 comprises an inner shell and an outer shell, with a gap between the inner and outer shells to allow for the flow of refrigerant. The power battery is placed within the inner shell and fits snugly against the outer shell.

[0031] It should be noted that, in this solution, the accommodating sleeve 42 has two ports, and both ports are connected to the accommodating tube 41 , so that the internal cavity of the accommodating sleeve 42 and the internal cavity of the accommodating tube 41 together constitute a channel.

[0032] In one embodiment, the accommodating pipe 41 has a first section 411 located on the side of the accommodating sleeve 42 close to the switching valve 2, and has a second section 412 located on the side of the accommodating sleeve 42 close to the first expansion valve 14, and the accommodating valve 43 is arranged in the first section 411; the electric heavy-duty truck thermal management system also includes a bypass pipe 5 and a bypass valve 51, the bypass pipe 5 is connected to the first section 411, and its connection point is located between the accommodating valve 43 and the accommodating sleeve 42, and is connected to the connecting pipeline between the switching valve 2 and the external heat exchanger 13, and the bypass valve 51 is arranged in the bypass pipe 5; the electric heavy-duty truck thermal management system also includes a first heater 6, and the first heater 6 is arranged in the second section 412.

[0033] In this embodiment, when the switching valve 2 connects the outlet 32 ​​of the refrigerant compressor 3 to the internal valve 12 and the bypass pipe 5 to the inlet 31 of the refrigerant compressor 3, the first expansion valve 14 and the receiving valve 43 are closed, the bypass valve 51 and the internal valve 12 are opened, and the first heater 6 is activated. At this point, the refrigerant flows through the following path: outlet 32 ​​of the refrigerant compressor 3 → switching valve 2 → internal valve 12 → internal heat exchanger 11 → first heater 6 → receiving shell → bypass valve 51 → switching valve 2 → inlet 31 of the refrigerant compressor 3. This allows the refrigerant to be heated by the first heater 6, thereby preheating the power battery and improving its operating efficiency in extremely cold environments.

[0034] It should be noted that the first heater 6 can be configured to be ceramic heating, infrared radiation heating, electric heating film heating or other heating methods. In this solution, the first heater 6 has a heating flow channel, which is connected to the first section 411 to improve heating efficiency.

[0035] In one embodiment, the connection between the bypass pipe 5 and the first section 411 is the first connection 52; the accommodating portion 4 also includes a first valve 44 and a second valve 45, the first valve 44 is arranged in the first section 411, and is located between the first connection 52 and the accommodating sleeve 42, and the second valve 45 is arranged in the second section 412, and is located on the side of the first heater 6 away from the accommodating sleeve 42.

[0036] In this embodiment, a first valve 44 and a second valve 45 are provided to improve the accuracy of switching between various modes. It should be noted that in this embodiment, the first valve 44, the second valve 45, the bypass valve 51, and the receiving valve 43 are all one-way valves, and the flow direction is directed toward the inlet end 31 of the compressor.

[0037] In one embodiment, the connection point between the connecting pipeline between the switching valve 2 and the external heat exchanger 13 and the bypass pipe 5 is the second connection point 53; the heat exchange part 1 also includes an external valve 15, which is arranged between the second connection point 53 and the external heat exchanger 13.

[0038] In this embodiment, an external valve 15 is further provided to prevent the refrigerant from flowing to the external heat exchanger 13 when preheating the power battery, thereby improving the heat exchange efficiency. Specifically, the internal valve 12 and the external valve 15 are also two-way valves.

[0039] In one embodiment, a second heater is provided on the external heat exchanger 13 to flexibly control the temperature of the refrigerant flowing through the external heat exchanger 13, further improving the flexibility of temperature adjustment. Specifically, the second heater and the first heater 6 are both positive temperature coefficient (PTC) electric heaters.

[0040] In one embodiment, see Figure 5The thermal management system of the electric heavy truck also includes a heat dissipation pipe 8, a heat dissipation sleeve 81, a coolant tank 82, a first heat exchanger 83 and a pump body 84. The heat dissipation pipe 8 is connected end to end. The inner cavity of the heat dissipation sleeve 81 is used to accommodate the motor assembly and is connected to the heat dissipation pipe 8. The coolant tank 82 is arranged on the heat dissipation pipe 8. The first heat exchanger 83 has a heat source flow channel and a heat absorption flow channel. The heat source flow channel is connected to the heat dissipation pipe 8. The pump body 84 is arranged on the heat dissipation pipe 8; the heat exchange part 1 also includes a waste heat pipe 16 and a waste heat valve 17. The waste heat pipe 16 is connected to the connecting pipeline between the internal heat exchanger 11 and the first expansion valve 14, and is connected to the connecting pipeline between the external heat exchanger 13 and the switching valve 2, and is connected to the heat absorption flow channel. The waste heat valve 17 is arranged on the waste heat pipe 16.

[0041] In this embodiment, waste heat recovery from the motor can be achieved. Specifically, the switching valve 2 is controlled to connect the outlet 32 ​​of the refrigerant compressor 3 to the internal valve 12, and the inlet 31 of the refrigerant compressor 3 to the external radiator and the waste heat pipe 16. The internal valve 12 and the waste heat valve 17 are controlled to open, and the accommodating valve 43 and the bypass valve 51 are controlled to close. The specific refrigerant flow path during waste heat recovery is as follows: outlet 32 ​​of the refrigerant compressor 3 → switching valve 2 → internal valve 12 → internal heat exchanger 11 → at least partially flowing to the heat absorption channel of the first heat exchange element 83 → switching valve 2 → inlet 31 of the refrigerant compressor 3. The coolant flow path on the motor side is as follows: liquid outlet of the heat dissipation jacket 81 → coolant tank 82 → heat source channel of the first heat exchange element 83 → pump body 84 → liquid inlet of the heat dissipation jacket 81.

[0042] It should be noted that the first heat exchanger 83 can be configured as a base, plate, or other structure with two flow channels. Specifically, in this embodiment, the first heat exchanger 83 is configured as a floor-type heat exchanger with two flow channels. Furthermore, in this embodiment, two heat dissipation jackets 81 are provided, sequentially accommodating the motor and motor controller along the direction approaching the coolant tank 82. Specifically, the heat dissipation jackets 81 can also be configured in the form of an outer shell and an inner shell, as described in detail in the "housing" section. The coolant tank 82 contains coolant.

[0043] In one embodiment, the thermal management system of the electric heavy truck also includes a cooling pipe 85, a second heat exchanger 86 and two control valves. The cooling pipe 85 has two access ends, both of which are connected to the heat dissipation pipe 8 and are located on both sides of the first heat exchanger 83. The second heat exchanger 86 has a flow channel connected to the cooling pipe 85. One of the two control valves is provided on the cooling pipe 85, and the other is provided on the heat dissipation pipe 8, and is located between the access end and the first heat exchanger 83.

[0044] In this embodiment, the battery side has two circuits: a cooling circuit and a heat exchange circuit. For ease of description, the control valve corresponding to the second heat exchange element 86 is defined as the cooling control valve 87, and the control valve corresponding to the first heat exchange element 83 is defined as the heat exchange control valve 88. The cooling circuit on the motor side controls the cooling control valve 87 to open and the heat exchange control valve 88 to close. The coolant flows as follows: the outlet of the heat dissipation jacket 81 → the coolant tank 82 → the cooling control valve 87 → the second heat exchange element 86 → the pump body 84 → the inlet of the heat dissipation jacket 81. At this time, the second heat exchange element 86 exchanges heat with the outside world to cool the coolant, ensuring that the coolant circulation cools the motor and motor controller. The heat exchange circuit is as follows: the outlet of the heat dissipation jacket 81 → the coolant tank 82 → the heat exchange control valve 88 → the first heat exchange element 83 → the pump body 84 → the inlet of the heat dissipation jacket 81.

[0045] It should be noted that the second heat exchange element 86 can be a heat exchange tube with a flow channel, a heat exchange seat or other structures. Specifically, in this solution, the second heat exchange element 86 is a second heat exchanger.

[0046] In one embodiment, the connection point between the connecting pipeline between the switching valve 2 and the external heat exchanger 13 and the waste heat pipe 16 is the third connection point 161, and the connection point between the connecting pipeline between the internal heat exchanger 11 and the first expansion valve 14 and the waste heat pipe 16 is the fourth connection point 162; the waste heat valve 17 includes a third valve 171, a second expansion valve 172 and a fourth valve 173, the third valve 171 and the second expansion valve 172 are arranged between the first heat exchange element 83 and the third connection point 161, the second expansion valve 172 and the fourth valve 173 are arranged between the first heat exchange element 83 and the fourth connection point 162, and are arranged in sequence along the direction close to the fourth connection point 162.

[0047] In this embodiment, the third valve 171, the second expansion valve 172, and the fourth valve 173 ensure efficient refrigerant circulation within the circuit while also ensuring stable operation of each circuit. The third valve 171 and the fourth valve 173 are one-way valves, both pointing away from the internal heat exchanger 11. It should be noted that in the present invention, each valve is a solenoid valve. Their specific structure and principles are known from the prior art and are not detailed here.

[0048] In addition, in this embodiment, the filter-drier 7 and the gas-liquid separator 9 are sequentially connected to the inlet end 31 of the refrigerant compressor 3 in a direction close to the switching valve 2 .

[0049] In addition, the present invention also provides a thermal management method, which is applied to the thermal management system of the electric heavy truck as described above, comprising: Obtaining an actual cabin temperature and a first preset cabin temperature range, obtaining an actual power battery temperature and a first preset power battery temperature range, and determining whether the actual cabin temperature meets the first preset cabin temperature range, and determining whether the actual power battery temperature meets the first preset power battery temperature range; If the actual temperature of the passenger cabin meets the first preset temperature range of the passenger cabin and the actual temperature of the power battery meets the first preset temperature range of the power battery, the accommodating portion is controlled to disconnect the passage, the inner valve and the first expansion valve are controlled to open, and the switching valve is controlled to connect the inner valve to the outlet of the refrigerant compressor and the external heat exchanger to the inlet of the refrigerant compressor; If the actual temperature of the power battery is greater than the first preset temperature range of the power battery, the accommodating portion is controlled to open the channel, the first expansion valve is controlled to open, and the switching valve is controlled to connect the channel to the inlet end of the refrigerant compressor, and the external heat exchanger is connected to the outlet end of the refrigerant compressor.

[0050] In this embodiment, when the actual cabin temperature is Tcab, which satisfies Tcab ≤ 25°C, and the actual power battery temperature is Tbat, which satisfies -10°C ≤ Tbat < 15°C, the valves are regulated to control cabin heating. When the actual power battery temperature Tbat is ≥ 15°C, the valves are regulated to control power battery cooling. The specific switching options for each mode are described below. It should be noted that the actual motor temperature is Tmot.

[0051] In order to better understand the present invention, the following Figures 1 to 6 The technical solution of the present invention is described in detail: The electric heavy-duty truck thermal management system in this solution has the following nine operating modes: ① Cabin cooling mode: open the inner valve 12, the outer valve 15, and the first expansion valve 14, and close the fourth valve 173, the second valve 45, the first valve 44, the accommodating valve 43, the bypass valve 51, the third valve 171, the cooling control valve 87, the heat exchange control valve 88, and the second expansion valve 172, and connect the outlet end 32 of the refrigerant compressor 3 to the outer valve 15 through the switching valve 2, and connect the inlet of the gas-liquid separator 9 to the inner valve 12. The flow path of the refrigerant is: the outlet end 32 of the refrigerant compressor 3 → the switching valve 2 → the outer valve 15 → the external heat exchanger 13 → the first expansion valve 14 → the inner heat exchanger 11 → the inner valve 12 → the switching valve 2 → the gas-liquid separator 9 → the filter dryer 7 → the inlet end 31 of the refrigerant compressor 3. At this time, the cooling circuit on the motor and motor controller side does not participate in the circulation.

[0052] ② Cabin heating mode: open the inner valve 12, outer valve 15, and first expansion valve 14, and close the fourth valve 173, second valve 45, first valve 44, accommodating valve 43, bypass valve 51, third valve 171, cooling control valve 87, heat exchange control valve 88, and second expansion valve 172. Connect the outlet 32 ​​of the refrigerant compressor 3 to the inner valve 12 and the inlet of the gas-liquid separator 9 to the outer valve 15 through the switching valve 2. The flow path of the refrigerant is: outlet 32 ​​of the refrigerant compressor 3 → switching valve 2 → inner valve 12 → inner heat exchanger 11 → first expansion valve 14 → outer heat exchanger 13 → outer valve 15 → switching valve 2 → gas-liquid separator 9 → filter dryer 7 → inlet 31 of the refrigerant compressor 3. At this time, the cooling circuit on the motor and motor controller side does not participate in the circulation.

[0053] ③ Power battery cooling mode: Open the external valve 15, first expansion valve 14, second valve 45, first valve 44, and receiving valve 43; close the internal valve 12, fourth valve 173, bypass valve 51, third valve 171, cooling control valve 87, heat exchange control valve 88, and second expansion valve 172; and connect the outlet 32 ​​of the refrigerant compressor 3 to the external valve 15 and the inlet of the gas-liquid separator 9 to the receiving valve 43 through the switching valve 2. The refrigerant flows as follows: outlet 32 ​​of the refrigerant compressor 3 → switching valve 2 → external valve 15 → external heat exchanger 13 → first expansion valve 14 → second valve 45 → first heater 6 → power battery → first valve 44 → receiving valve 43 → switching valve 2 → gas-liquid separator 9 → filter-drier 7 → inlet 31 of the refrigerant compressor 3. At this time, the cooling circuits on the motor and motor controller side do not participate in the circulation, and the first heater 6 is not powered.

[0054] ④ Power battery preheating mode: open the inner valve 12, the second valve 45, the first valve 44, and the bypass valve 51; close the outer valve 15, the fourth valve 173, the accommodating valve 43, the third valve 171, the cooling control valve 87, the heat exchange control valve 88, the first expansion valve 14, and the second expansion valve 172; and connect the outlet 32 ​​of the refrigerant compressor 3 to the inner valve 12 through the switching valve 2, and connect the inlet of the gas-liquid separator 9 to the bypass valve 51. The refrigerant flows through the following path: outlet 32 ​​of the refrigerant compressor 3 → switching valve 2 → inner valve 12 → inner heat exchanger 11 → second valve 45 → first heater 6 → power battery → first valve 44 → bypass valve 51 → switching valve 2 → gas-liquid separator 9 → filter dryer 7 → inlet 31 of the refrigerant compressor 3. At this time, the cooling circuit on the motor and motor controller side does not participate in the circulation, and the first heater 6 is energized and works.

[0055] ⑤ Cabin and power battery cooling mode: Open the inner valve 12, outer valve 15, first expansion valve 14, second valve 45, first valve 44, and receiving valve 43. Close the second expansion valve 172, fourth valve 173, bypass valve 51, third valve 171, cooling control valve 87, and heat exchange control valve 88. Connect the outlet 32 ​​of the refrigerant compressor 3 to the outer valve 15 via the switching valve 2. Connect the inlet of the gas-liquid separator 9 to the receiving valve 43 and the inner valve 12. The refrigerant flows through two paths: one for cabin cooling and the other for power battery cooling. The cabin cooling path is: outlet 32 ​​of the refrigerant compressor 3 → switching valve 2 → outer valve 15 → external heat exchanger 13 → first expansion valve 14 → inner heat exchanger 11 → inner valve 12 → switching valve 2 → gas-liquid separator 9 → filter-drier 7 → inlet 31 of the refrigerant compressor 3.

[0056] The power battery cooling path is: outlet port 32 of refrigerant compressor 3 → switching valve 2 → external valve 15 → external heat exchanger 13 → first expansion valve 14 → second valve 45 → first heater 6 → power battery → first valve 44 → accommodating valve 43 → switching valve 2 → gas-liquid separator 9 → filter-drier 7 → inlet port 31 of refrigerant compressor 3. At this time, the cooling circuit on the motor and motor controller side is not involved in the circulation, and the first heater 6 is not powered.

[0057] ⑥Cockpit and power battery heating mode: open the inner valve 12, outer valve 15, first expansion valve 14, second valve 45, first valve 44, and bypass valve 51, and close the second expansion valve 172, fourth valve 173, accommodating valve 43, third valve 171, cooling control valve 87, and heat exchange control valve 88, and connect the outlet end 32 of the refrigerant compressor 3 to the inner valve 12 through the switching valve 2, and connect the inlet of the gas-liquid separator 9 to the bypass valve 51 and the outer valve 15. The flow path of the refrigerant is divided into two paths, one is the cockpit heating path, and the other is the power battery heating path.

[0058] Among them, the heating path of the cockpit is: the outlet end 32 of the refrigerant compressor 3 → the switching valve 2 → the internal valve 12 → the internal heat exchanger 11 → the first expansion valve 14 → the external heat exchanger 13 → the external valve 15 → the switching valve 2 → the gas-liquid separator 9 → the filter dryer 7 → the inlet end 31 of the refrigerant compressor 3.

[0059] The power battery heating path is: outlet port 32 of refrigerant compressor 3 → switching valve 2 → internal valve 12 → internal heat exchanger 11 → second valve 45 → first heater 6 → power battery → first valve 44 → bypass valve 51 → switching valve 2 → gas-liquid separator 9 → filter-drier 7 → inlet port 31 of refrigerant compressor 3. At this time, the cooling circuit on the motor and motor controller side is not involved in the circulation, and the first heater 6 is energized and operational.

[0060] ⑦ Cabin heating and motor waste heat recovery mode: open the inner valve 12, outer valve 15, first expansion valve 14, second expansion valve 172, fourth valve 173, third valve 171, and heat exchange control valve 88, close the second valve 45, first valve 44, accommodating valve 43, bypass valve 51, and cooling control valve 87, and connect the outlet end 32 of the refrigerant compressor 3 to the inner valve 12 through the switching valve 2, and connect the inlet of the gas-liquid separator 9 to the outer valve 15. The flow path of the refrigerant is divided into two paths, one is the cabin heating path, and the other is the motor waste heat recovery path.

[0061] Among them, the heating path of the cockpit is: the outlet end 32 of the refrigerant compressor 3 → the switching valve 2 → the internal valve 12 → the internal heat exchanger 11 → the first expansion valve 14 → the external heat exchanger 13 → the external valve 15 → the switching valve 2 → the gas-liquid separator 9 → the filter dryer 7 → the inlet end 31 of the refrigerant compressor 3.

[0062] The motor waste heat recovery path is: the outlet end 32 of the refrigerant compressor 3 → the switching valve 2 → the internal valve 12 → the internal heat exchanger 11 → the fourth valve 173 → the second expansion valve 172 → the heat absorption flow channel of the first heat exchange element 83 → the third valve 171 → the external valve 15 → the switching valve 2 → the gas-liquid separator 9 → the filter dryer 7 → the inlet end 31 of the refrigerant compressor 3.

[0063] At this time, the cooling circuit on the motor and motor controller side participates in the circulation, and the circulation path of the coolant is: outlet of the coolant tank 82 → heat exchange control valve 88 → heat source flow channel of the first heat exchange element 83 → pump body 84 → heat dissipation sleeve 81 → inlet of the coolant tank 82.

[0064] ⑧ Cooling mode of the passenger cabin, motor and motor controller: open the inner valve 12, outer valve 15, first expansion valve 14 and cooling control valve 87, close the fourth valve 173, second valve 45, first valve 44, accommodating valve 43, bypass valve 51, third valve 171, heat exchange control valve 88 and second expansion valve 172, and connect the outlet end 32 of the refrigerant compressor 3 to the outer valve 15 through the switching valve 2, and connect the inlet of the gas-liquid separator 9 to the inner valve 12. The flow path of the refrigerant is: outlet end 32 of the refrigerant compressor 3 → switching valve 2 → outer valve 15 → outer heat exchanger 13 → first expansion valve 14 → inner heat exchanger 11 → inner valve 12 → switching valve 2 → gas-liquid separator 9 → filter dryer 7 → inlet end 31 of the refrigerant compressor 3.

[0065] At this time, the cooling circuit on the motor and motor controller side participates in the circulation, and the circulation path of the coolant is: coolant tank 82 outlet → cooling control valve 87 → second heat exchange element 86 → pump body 84 → heat dissipation jacket 81 → coolant tank 82 inlet.

[0066] ⑨ Cooling mode for the passenger cabin, power battery, motor and motor controller: open the inner valve 12, outer valve 15, first expansion valve 14, second valve 45, first valve 44, accommodating valve 43 and cooling control valve 87; close the fourth valve 173, bypass valve 51, third valve 171, heat exchange control valve 88 and second expansion valve 172; and connect the outlet end 32 of the refrigerant compressor 3 to the outer valve 15 through the switching valve 2, and connect the inlet of the gas-liquid separator 9 to the inner valve 12. The flow path of the refrigerant is divided into two paths, one is the passenger cabin cooling path, and the other is the power battery cooling path.

[0067] Among them, the cabin cooling path is: the outlet end 32 of the refrigerant compressor 3 → the switching valve 2 → the external valve 15 → the external heat exchanger 13 → the first expansion valve 14 → the internal heat exchanger 11 → the internal valve 12 → the switching valve 2 → the gas-liquid separator 9 → the filter dryer 7 → the inlet end 31 of the refrigerant compressor 3.

[0068] The power battery cooling path is: outlet end 32 of refrigerant compressor 3 → switching valve 2 → external valve 15 → external heat exchanger 13 → first expansion valve 14 → second valve 45 → first heater 6 → power battery → first valve 44 → accommodating valve 43 → switching valve 2 → gas-liquid separator 9 → filter dryer 7 → inlet end 31 of refrigerant compressor 3.

[0069] At this time, the cooling circuit on the motor and motor controller side participates in the circulation, and the circulation path of the coolant is: coolant tank 82 → cooling control valve 87 → second heat exchanger 86 → pump body 84 → motor → motor controller → coolant tank 82, and the first heater 6 is not powered on.

[0070] The specific control methods of the above nine working modes include: Power battery thermal management control method: Obtain the operating temperature of the power battery; determine whether the operating temperature is less than -10°C; if so, activate the power battery preheating mode; if not, further determine whether the operating temperature is less than 0°C. If so, activate the power battery preheating mode while activating the cabin heating and motor waste heat recovery mode; if not, further determine whether the operating temperature is less than 15°C. If so, deactivate the power battery preheating mode and activate the cabin heating / motor waste heat recovery mode; if not, further determine whether the operating temperature is less than 45°C. If so, deactivate all eight modes except the power battery cooling mode; if not, keep the power battery cooling mode on. Repeatedly determine whether the operating temperature is less than -10°C.

[0071] The passenger cabin thermal management control method: obtains the passenger cabin operating temperature; determines whether the operating temperature is less than 15°C; if so, activates the passenger cabin heating and motor waste heat recovery modes, and simultaneously energizes the second heater 7; if not, further determines whether the operating temperature is less than 20°C. If so, maintains the passenger cabin heating and motor waste heat recovery modes in the enabled state, and deenergizes the second heater 7 to stop heating; if not, further determines whether the operating temperature is greater than 25°C. If so, activates the passenger cabin cooling mode; if not, activates the passenger cabin heating mode, and disables the heat pump waste heat recovery circuit. This cyclic determination of whether the operating temperature is less than 15°C continues.

[0072] Motor and motor controller thermal management control method: obtain the operating temperature of the motor and motor controller; determine whether the operating temperature is less than 60°C; if so, disable the nine operating modes; if not, enable the cabin and motor and motor controller cooling mode. Repeat the process of determining whether the operating temperature is less than 60°C.

[0073] The present invention has the following beneficial effects: 1. The electric heavy-duty truck thermal management system provided by this invention uses refrigerant instead of traditional coolant to directly heat or cool the power battery, eliminating the existing liquid cooling system, reducing the weight of the electric heavy-duty truck, and also saving energy. The heat dissipation and preheating requirements of the power battery of an electric heavy-duty truck are far greater than those of a pure electric small or medium-sized vehicle. The refrigerant has a higher latent heat of phase change cooling than the coolant, a higher heat absorption capacity per unit mass, and a faster cooling rate, making it more suitable for the heavy-load, high-power application requirements of electric heavy-duty trucks. Compared to secondary cooling of the coolant, the refrigerant directly contacts the power battery liquid cooling plate, which can reduce thermal resistance and improve temperature uniformity.

[0074] 2. The nine working modes provided by the present invention can achieve cabin cooling and heating, power battery cooling and preheating, simultaneous cooling of the cabin and power battery, simultaneous heating of the cabin and power battery, simultaneous motor waste heat recovery while heating the cabin, simultaneous cooling of the cabin, motor, and motor controller, and simultaneous cooling of the cabin, power battery, motor, and motor controller.

[0075] 3. The electric heavy-duty truck thermal management system provided by the present invention can achieve refined management and control of the driver's cabin, power battery, motor and motor controller of the electric heavy-duty truck thermal management system by controlling the opening and closing switching of the one-way solenoid valve, the two-way solenoid valve and the electronic expansion valve. The thermal regulation is centralized, and the waste heat recovery of the motor effectively extends and improves the system efficiency, reduces the energy consumption of the power battery, improves the comfort of the driver's cabin, and increases the endurance and safety of the electric heavy-duty truck under winter conditions.

[0076] 4. The thermal management method provided by the present invention obtains the operating temperatures of the cabin, power battery, motor and motor controller in real time. Under winter working conditions, when the electric heavy-duty truck is operating stably and the evaporator is frosted, the first heater 6 and the second heater 7 are used to preheat the system. When the power battery temperature exceeds 0°C and the cabin temperature exceeds 15°C, the PTC electric heating is stopped to save energy. At this time, the heating demand of the power battery and the cabin is reduced, and the recovered motor waste heat can not only continue to heat the power battery and the cabin, improving the cabin comfort, but also save power battery energy consumption and increase the cruising range of the electric heavy-duty truck.

[0077] The specific embodiments of the present invention described above do not limit the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A thermal management system for an electric heavy truck, characterized in that: include: The heat exchange part includes an internal heat exchanger, an internal valve, an external heat exchanger and a first expansion valve connected end to end; a switching valve having two first ports and two second ports, and capable of controlling each first port to independently connect to and disconnect from each second port, wherein the two second ports are connected to the connecting pipeline between the inner valve and the outer heat exchanger; a refrigerant compressor, the inlet and outlet of which are respectively connected to the two first ports; and The accommodating portion has a channel for accommodating a power battery and can control the on-off of the channel. The channel connects the connecting pipeline between the switching valve and the inner valve, and connects the connecting pipeline between the first expansion valve and the inner heat exchanger.

2. The thermal management system for electric heavy trucks according to claim 1, characterized in that: The accommodating portion includes an accommodating tube, an accommodating sleeve and an accommodating valve. One end of the accommodating tube is connected to the connecting pipeline between the switching valve and the inner valve, and the other end is connected to the connecting pipeline between the first expansion valve and the inner heat exchanger. The accommodating sleeve is arranged on the accommodating tube and is used to accommodate the power battery. It and the internal cavity of the accommodating tube together constitute the channel. The accommodating valve is arranged on the accommodating tube.

3. The thermal management system for electric heavy trucks according to claim 2, characterized in that: The accommodating pipe has a first section located on a side of the accommodating sleeve close to the switching valve, and has a second section located on a side of the accommodating sleeve close to the first expansion valve, and the accommodating valve is provided in the first section; The electric heavy-duty truck thermal management system further includes a bypass pipe and a bypass valve. The bypass pipe is connected to the first section, and its connection point is located between the accommodating valve and the accommodating sleeve, and is connected to the connecting pipeline between the switching valve and the external heat exchanger. The bypass valve is provided on the bypass pipe. The electric heavy truck thermal management system further includes a first heater, which is disposed in the second section.

4. The thermal management system for electric heavy trucks according to claim 3, characterized in that: The connection between the bypass pipe and the first section is a first connection; The accommodating portion further includes a first valve and a second valve. The first valve is provided in the first section and located between the first connection and the accommodating sleeve. The second valve is provided in the second section and located on a side of the first heater away from the accommodating sleeve.

5. The thermal management system for electric heavy trucks according to claim 3, characterized in that: The connection point between the connecting pipe between the switching valve and the external heat exchanger and the bypass pipe is the second connection point; The heat exchange portion further includes an external valve, which is arranged between the second connection point and the external heat exchanger.

6. The thermal management system for electric heavy trucks according to claim 1, characterized in that: The inlet end of the refrigerant compressor is sequentially connected to a filter dryer and a gas-liquid separator along a direction close to the switching valve.

7. The thermal management system for electric heavy trucks according to claim 1, characterized in that: The electric heavy truck thermal management system further includes a heat pipe, a heat sink, a coolant tank, a first heat exchange element, and a pump body. The heat pipe is connected end to end. The inner cavity of the heat sink is used to accommodate the motor assembly and is connected to the heat pipe. The coolant tank is arranged on the heat pipe. The first heat exchange element has a heat source flow channel and a heat absorption flow channel. The heat source flow channel is connected to the heat pipe. The pump body is arranged on the heat pipe. The heat exchange part also includes a waste heat pipe and a waste heat valve. The waste heat pipe connects the connecting pipeline between the internal heat exchanger and the first expansion valve, connects the connecting pipeline between the external heat exchanger and the switching valve, and is connected to the heat absorption flow channel. The waste heat valve is arranged on the waste heat pipe.

8. The thermal management system for an electric heavy truck according to claim 7, characterized in that: The electric heavy-duty truck thermal management system also includes a cooling pipe, a second heat exchanger and two control valves. The cooling pipe has two access ends, both of which are connected to the heat dissipation pipe and are located on both sides of the first heat exchanger. The second heat exchanger has a flow channel connected to the cooling pipe. One of the two control valves is provided on the cooling pipe, and the other is provided on the heat dissipation pipe and is located between the access end and the first heat exchanger.

9. The thermal management system for electric heavy trucks according to claim 7, characterized in that: The connection point between the connecting pipe between the switching valve and the external heat exchanger and the waste heat pipe is the third connection point, and the connection point between the connecting pipe between the internal heat exchanger and the first expansion valve and the waste heat pipe is the fourth connection point; The waste heat valve includes a third valve, a second expansion valve and a fourth valve. The third valve and the second expansion valve are arranged between the first heat exchange element and the third connection point, and the second expansion valve and the fourth valve are arranged between the first heat exchange element and the fourth connection point, and are arranged in sequence along the direction close to the fourth connection point.

10. A thermal management method for an electric heavy truck, applied to the thermal management system for an electric heavy truck according to any one of claims 1 to 9, characterized in that: include; obtaining an actual cabin temperature and a first preset cabin temperature range, obtaining an actual power battery temperature and a first preset power battery temperature range, and determining whether the actual cabin temperature meets the first preset cabin temperature range, and determining whether the actual power battery temperature meets the first preset power battery temperature range; If the actual temperature of the passenger cabin meets the first preset temperature range of the passenger cabin and the actual temperature of the power battery meets the first preset temperature range of the power battery, controlling the accommodating portion to disconnect the passage, controlling the inner valve and the first expansion valve to open, and controlling the switching valve to connect the inner valve to the outlet of the refrigerant compressor and to connect the external heat exchanger to the inlet of the refrigerant compressor; If the actual temperature of the power battery is greater than the first preset temperature range of the power battery, the accommodating portion is controlled to connect the channel, the first expansion valve is controlled to open, and the switching valve is controlled to connect the channel to the inlet end of the refrigerant compressor, and the external heat exchanger is connected to the outlet end of the refrigerant compressor.

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