Thermal management system for electric truck and electric truck

Abstract

The invention relates to a thermal management system for an electric truck and the electric truck. A thermal management system for an electric truck includes a first heat pump module including a first coolant circuit, a first refrigerant circuit, a first module controller, a second heat pump module including a second coolant circuit, a second refrigerant circuit, and a second module controller, the first refrigerant circuit and the second refrigerant circuit are independent of each other, and the first refrigerant circuit is individually controlled by the first module controller and the second refrigerant circuit is individually controlled by the second module controller, and wherein the first coolant circuit and the second coolant circuit are connected in parallel, the first coolant circuit and the second coolant circuit are symmetrically controlled by the first module controller and the second module controller, respectively. The invention further relates to an electric truck with the thermal management system.

Description

Technical Field

[0001] The present invention relates to a thermal management system for an electric truck, in particular an electric heavy-duty truck. The present invention also relates to an electric truck having the thermal management system, in particular an electric heavy-duty truck. Background Art

[0002] With the rapid development of new energy heavy-duty truck technology, more urgent and severe challenges are posed to thermal management control technology suitable for large loads, low energy consumption and high stability.

[0003] The capacity of a single heat pump module is limited by the pump capacity and the flow resistance of the circuit. It is difficult for a single heat pump module to meet the large water flow requirements of the vehicle system. In addition, the capacity of a single heat pump module is also limited by the capacity of the compressor and the expansion valve. The cooling or heating capacity of a single heat pump module is difficult to meet the requirements of a heavy-duty truck with a large load.

[0004] In addition, the thermal management system of heavy-duty trucks is significantly different from that of passenger cars, so it is difficult to transfer the thermal management system of passenger cars to heavy-duty trucks. Summary of the invention

[0005] The technical problem to be solved by the present invention is to at least partially overcome the above-mentioned technical defects to realize a stable and efficient thermal management system that meets the thermal requirements of the entire electric truck and has expansion capabilities.

[0006] The present invention relates to a thermal management system for an electric truck, comprising: a first heat pump module, the first heat pump module comprising a first coolant circuit, a first refrigerant circuit, and a first module controller, a second heat pump module, the second heat pump module comprising a second coolant circuit, a second refrigerant circuit, and a second module controller, wherein the first refrigerant circuit and the second refrigerant circuit are independent of each other, and the first refrigerant circuit is independently controlled by the first module controller, and the second refrigerant circuit is independently controlled by the second module controller, and wherein the first coolant circuit and the second coolant circuit are connected in parallel, and the first coolant circuit and the second coolant circuit are symmetrically controlled by the first module controller and the second module controller, respectively.

[0007] The thermal management system of the present invention realizes a modular design of heat pumps, especially a dual heat pump module system. Compared with a single heat pump module system, a dual heat pump module system is more complex. It not only has the working function of a single heat pump, but also has the collaborative working function of dual heat pump modules, so that the dual heat pump module system can operate stably and efficiently in all scenarios of the whole vehicle to meet the thermal needs of the whole vehicle. Like the traditional single heat pump module system, the dual heat pump module system can realize the transfer, recovery, heat storage and reuse of the heat of the whole vehicle, thereby reducing energy consumption. However, the capacity of a single heat pump system is difficult to efficiently meet the super-large heat load requirements of various systems of heavy-duty trucks. The dual heat pump module solves the problems of high heat load and high energy consumption of new energy heavy-duty trucks, and further promotes the development of new energy heavy-duty truck technology. In the dual heat pump module control system proposed by the present invention, the first coolant loop and the second coolant loop are symmetrically controlled by the first module controller and the second module controller respectively, so in most scenarios, the dual heat pump modules are synchronously operated at the same frequency and speed, and the heat demand of the whole vehicle is evenly shared by the two heat pump modules, which not only doubles the system capacity, but also allows the components of each heat pump module to work in a more efficient range for a long time, thereby improving the service life of the components of the heat pump module. In the scope of the present invention, "same" for parameters such as speed, temperature, and opening refers to a deviation of no more than 5%.

[0008] In addition, because it is difficult to make the actual vehicle components or layout of the two heat pump modules completely consistent or symmetrical, it is also difficult to make the water system performance completely consistent, which will affect the capacity output and control stability of the refrigerant circuit. According to the present invention, the refrigerant circuit of each module is independently closed-loop controlled within the module, which can solve the technical problem that the instability of the water circuit affects the control stability of the refrigerant circuit. Because the two refrigerant circuits have the same control target, through the closed-loop adjustment of each refrigerant circuit, the thermal management requirements of the entire vehicle are finally achieved in a coordinated manner.

[0009] According to one embodiment, the first heat pump module and the second heat pump module are constructed as the same heat pump module. The dual heat pump module proposed by the present invention is structurally two single heat pump modules connected in parallel with the vehicle coolant circuit of the electric truck through a valve device, especially a three-way valve. The two modules have the same components and layout, and can use the same communication protocol. As a result, the same control strategy can be used in terms of control, which simplifies the control strategy, and the two heat pump modules can operate in a balanced manner.

[0010] According to one implementation form, the thermal management system further includes at least one third heat pump module, and the third heat pump module is constructed as the same heat pump module as the first heat pump module and the second heat pump module. The heat pump module according to the present invention can be easily expanded because a modular design is performed in terms of structural layout, control strategy, and communication protocol at the beginning of the design, so it can be adapted to different vehicle models, different working conditions, and different requirements.

[0011] According to one embodiment, the first coolant circuit includes a first multi-way valve, a first pump and a first heat exchanger, the first refrigerant circuit includes a first compressor, a first condenser, a first expansion valve and a first evaporator, wherein the first heat exchanger is coupled to the first condenser and / or the first evaporator, and the second coolant circuit includes a second multi-way valve, a second pump and a second heat exchanger, the second refrigerant circuit includes a second compressor, a second condenser, a second expansion valve and a second evaporator, wherein the second heat exchanger is coupled to the second condenser and / or the second evaporator. Here, the first multi-way valve and the second multi-way valve are configured to control the flow of the coolant, that is, different thermal management modes can be switched, such as battery cooling mode, battery heating mode, air conditioning heating mode, air conditioning cooling mode, electric drive and electric control cooling mode and any combination thereof, and for different thermal management modes, different subsystems are required to flow the coolant. In the scope of the present invention, the coolant includes water. And in the scope of the present invention, the multi-way valve is at least a three-way valve, and can even be a seven-way valve and a nine-way valve.

[0012] According to one implementation form, the first multi-way valve and the first pump are controlled by the first module controller, and the second multi-way valve and the second pump are controlled by the second module controller, wherein, according to the target demand, the first module controller adjusts the opening of the first multi-way valve and the speed of the first pump, and the second module controller adjusts the opening of the second multi-way valve and the speed of the second pump, wherein the speed of the first pump and the speed of the second pump are adjusted to make the coolant flow of the first heat pump module and the second heat pump module the same. It is currently known that the water circuit of the integrated heat pump system is relatively complex, and common problems include heat mixing between systems, water circuit backflow not meeting the expected design, etc. The dual heat pump module integrated system further exacerbates the complexity of the water circuit, which not only puts forward higher design requirements for product design, but also poses great challenges to system control. Considering the actual layout environment of the whole vehicle, the dual heat pump module system cannot be strictly symmetrically arranged in physical structure, and there are certain differences in the pipelines. When these differences are large, it will affect the actual water channel flow resistance of the two modules, resulting in a large difference in the water flow of the two modules, and even the risk of water mixing between the two modules. Unexpected flow direction will not only cause energy loss, but also affect thermal management functions; large differences in water flow between the two modules will also lead to large differences in the output capacity of the two modules. Long-term differences will cause the module with larger output capacity to consume its life faster. In view of the above problems, by coordinating the speed of the pump of each module or the opening of the multi-way valve of each module, the water flow performance of the two modules in each system mode can be monitored separately, and the pump speed that not only meets the flow requirements of the vehicle system but is also basically equal can be calibrated. The balance of water flow can ensure that the output capacity of the two modules is basically consistent and solve the above problems.

[0013] According to one implementation form, 2 to 10 seconds before the first multi-way valve is switched, the speed of the first pump is first reduced to the minimum speed, and then restored to normal operation after the first multi-way valve is switched; similarly, 2 to 10 seconds before the second multi-way valve is switched, the speed of the second pump is first reduced to the minimum speed, and then restored to normal operation after the second multi-way valve is switched. When the mode multi-way valve is switched, the water flow and flow direction during the switching process are unexpected. The multi-way valve switching stroke time is generally 2 to 10 seconds. The switching process will inevitably cause water mixing between systems, resulting in heat loss. The dual heat pump module system has a larger flow rate, and the heat loss during the switching process is more serious. In order to reduce the heat loss during the switching process, each module requires coordinated control operation between parts. Before the multi-way valve has a switching requirement, the pump speed in the coolant circuit is reduced to the minimum speed in advance. The multi-way valve is switched and the pump resumes normal operation. The coordinated control between parts reduces the heat loss to the greatest extent without affecting the heat dissipation requirements of each system.

[0014] According to one embodiment, the first compressor and the first expansion valve are controlled by a first module controller, and the second compressor and the second expansion valve are controlled by a second module controller, wherein, according to the same target requirements, the first module controller controls the speed of the first compressor and the opening of the first expansion valve, and the second module controller controls the speed of the second compressor and the opening of the second expansion valve.

[0015] According to one implementation form, the thermal management system includes a battery thermal management subsystem, an electric drive and electric control thermal management subsystem, an air conditioning thermal management subsystem, a thermal management mode selection unit, and a module capacity allocation unit, wherein the thermal management mode selection unit selects a thermal management mode according to the requirements of the battery thermal management subsystem, the electric drive and electric control thermal management subsystem, and the air conditioning thermal management subsystem, and the module capacity allocation unit allocates output capacity to the first heat pump module through the first module controller according to the selected thermal management mode, and allocates output capacity to the second heat pump module through the second module controller. The control architecture according to the present invention realizes a more efficient and stable operation mode. Due to the modular design of the control architecture, the coolant circuit is symmetrically controlled, and the refrigerant circuits are independently controlled in a closed loop. Each heat pump module can fully output power to meet the vehicle control target.

[0016] According to one embodiment, the first coolant circuit and the second coolant circuit are connected in parallel with the vehicle coolant circuit of the electric truck through a valve device, wherein the vehicle coolant circuit includes a battery pack coolant circuit and an electric drive electronic control coolant circuit, wherein the first multi-way valve and the second multi-way valve are respectively connected to the battery pack coolant circuit and / or the electric drive electronic control coolant circuit. The valve device described herein is a three-way valve, and may also be other types of valves according to different scenarios. Here, the first multi-way valve and the second multi-way valve can realize the series connection of the dual heat pump module system and the battery pack coolant circuit and / or the electric drive electronic control coolant circuit. For the first multi-way valve and the second multi-way valve, the temperature and flow rate of the coolant refluxed in the coolant circuit are different, so the opening of the first multi-way valve and the second multi-way valve can be adjusted, and the speed of the first pump and the second pump can be adjusted if necessary to achieve substantially the same coolant flow rate. Similarly, according to the allocated capacity, the compressor and expansion valve in each module can also be adjusted to provide different cooling capacity or heating capacity to meet the needs of the whole vehicle. Thus, independent control of the refrigerant circuits provides compensation and balancing for capacity differences between the heat pump modules (eg due to long-term use).

[0017] Another aspect of the present invention also relates to an electric truck having a thermal management system according to the present invention. The embodiments and advantages of the thermal management system are naturally also applicable to the electric truck according to the present invention.

[0018] In general, the dual heat pump module system control architecture proposed in the present invention provides a new control idea for the thermal management control technology of new energy heavy-duty trucks. The development of more efficient thermal management technology makes it possible for new energy heavy-duty trucks to achieve greater power performance, greater charging power, and higher energy efficiency requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above-mentioned features and advantages of the present invention and the methods for achieving them are described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings, but the features of the present invention are not limited to the features of the specific embodiments. In the accompanying drawings: Figure 1 A working principle diagram of a thermal management system according to the present invention is shown; Figure 2 A schematic diagram of a thermal management system according to the present invention is shown. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Unless otherwise defined, the technical or scientific terms used herein shall have the usual meanings understood by persons of ordinary skill in the field to which the invention belongs. The words "first", "second" and similar terms used in the patent application specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Front", "back", "upper", "lower", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0022] The drawings in the present invention are not drawn strictly according to the actual scale, and are regarded as provisions of the present invention only when the size and position relationship are clearly stated, and the specific size and quantity of each structure can be determined according to actual needs.

[0023] The following elements are generally shown in the accompanying drawings: a power source P, a battery thermal management subsystem 10, an electric drive and electronic control thermal management subsystem 20, an air conditioning thermal management subsystem 30, a thermal management mode selection unit 40, a module capacity allocation unit 50, a coolant demand unit 60, a multi-way valve mode demand unit 70, a refrigerant demand unit 80, a heater demand unit 90, a first heat pump module 100, a first module controller 102, a first multi-way valve 104, a first pump 106, a first heat exchanger 108, a first compressor 110, a first condenser 112, a first expansion valve 114, a first heater 118, a second heat pump module 200, a second module controller 202, a second multi-way valve 204, a second pump 206, a second heat exchanger 208, a second compressor 210, a second condenser 212, a second expansion valve 214, a second heater 218, a three-way valve 12, and a demand system 14.

[0024] Figure 1The working principle diagram of the thermal management system according to the present invention is shown. Starting from the power supply P being powered on (the whole vehicle being powered on), the requirements of the battery thermal management subsystem 10, the electric drive and electric control thermal management subsystem 20 and the air conditioning thermal management subsystem 30 are calculated or detected respectively, and then the current thermal management mode is obtained in the thermal management mode selection unit 40. The thermal management mode may include multiple modes, such as battery cooling mode, air conditioning heating mode, air conditioning refrigeration mode, etc., or a combination of several modes. After the thermal management mode is determined, tasks are assigned to each heat pump module through the module capacity allocation unit 50, for example, by sending signals to the module controllers of each heat pump module.

[0025] exist Figure 1 Three heat pump modules are schematically shown in Figure 2 ), these heat pump modules can be constructed identically or expanded to four, five or more. Figure 1 In the schematic diagram of , three heat pump modules are shown to reflect the scalability, wherein the third heat pump module is constructed in the same manner as the first heat pump module and the second heat pump module, and corresponding components have corresponding reference numerals. Figure 2 In the embodiment of , the thermal management system has only two heat pump modules, namely a first heat pump module 100 and a second heat pump module 200. The first heat pump module 100 includes a first coolant circuit, a first refrigerant circuit and a first module controller 102, the first coolant circuit includes a first multi-way valve 104, a first pump 106, a first heat exchanger 108 and a first heater 118, the first refrigerant circuit includes a first compressor 110, a first condenser 112, a first expansion valve 114 and a first evaporator, wherein the first heat exchanger is coupled to the first evaporator. The second heat pump module 200 includes a second coolant circuit, a second refrigerant circuit, a second module controller 202, and the second coolant circuit includes a second multi-way valve 204, a second pump 206, a second heat exchanger 208 and a second heater 218, the second refrigerant circuit includes a second compressor 210, a second condenser 212, a second expansion valve 214 and a second evaporator, wherein the second heat exchanger is coupled to the second evaporator. Therefore, with Figure 2 Correspondingly, Figure 1 The third heat pump module in the embodiment has a third module controller 302 , a third multi-way valve 304 , a third pump 306 , a third compressor 110 , a third expansion valve 114 and a third heater 118 , which are controlled and adjusted by the third module controller 302 .

[0026] The module capacity allocation unit 50 allocates tasks to the first module controller 102, the second module controller 202 and the third module controller 303, and each module controller controls its own multi-way valve, pump, compressor, expansion valve and heater to meet various requirements. Here, the coolant demand unit 60 obtains or uses the heat of the coolant provided by the first pump, the second pump and the third pump (the heat can also be the coldness in the present invention), and feeds back the relevant parameters of the coolant demand unit 60 (such as the battery temperature, etc.) to the start. In addition, the multi-way valve mode demand unit 70 obtains the multi-way valve mode of the first multi-way valve, the second multi-way valve and the third multi-way valve, and feeds back its own requirements to the start. In addition, the refrigerant demand unit 80 obtains the heat of the refrigerant side provided by the first compressor, the second compressor, the third compressor and the first expansion valve, the second expansion valve and the third expansion valve, and sends its own relevant parameters to the start. The heater demand unit 90 obtains the heat of the coolant provided by the first heater, the second heater and the third heater, and sends its own relevant parameters to the start. The relevant parameters of each unit are collected, and then the requirements of each subsystem are calculated again, and the work of demand judgment and capacity allocation is continued to be completed, so that the thermal management system can accurately allocate the capacity of each module and operate efficiently and stably.

[0027] Furthermore, in the present invention, the demand of the entire vehicle can be obtained by only monitoring the coolant demand unit 60, the multi-way valve mode demand unit 70, the refrigerant demand unit 80 and the heater demand unit 90.

[0028] Combination Figure 2, the present invention is explained in a specific multi-way valve mode or thermal management mode. The first multi-way valve 104 and the second multi-way valve 204 shown here are only schematic (i.e., the interface with other systems is not shown), because the multi-way valve is also connected to other circuits for cooling or heating other systems. For example, the battery cooling mode is selected here, the demand system 14 is the battery pack here, and the multi-way valve is controlled so that the coolant flows through the battery pack and directly returns to the heat pump module without passing through other systems. During operation, the temperature of the battery pack is detected, which can be completed in the battery thermal management subsystem 10, and then the battery cooling mode is selected in the thermal management mode selection unit 40 according to the measured temperature, and then the capacity is allocated to the first heat pump module and the second heat pump module according to the mode (in the module capacity allocation unit 50). According to the allocation or target demand, the first compressor and the first expansion valve are controlled by the first module controller, and the second compressor and the second expansion valve are controlled by the second module controller. Specifically, the first module controller controls the speed of the first compressor and the opening of the first expansion valve, and the second module controller controls the speed of the second compressor and the opening of the second expansion valve. At the same time, according to the target demand, the first module controller adjusts the opening of the first multi-way valve and the speed of the first pump, and the second module controller adjusts the opening of the second multi-way valve and the speed of the second pump, wherein the speed of the first pump and the speed of the second pump are adjusted to make the coolant flow of the first heat pump module and the second heat pump module the same. In addition, the compressor and the expansion valve can be adjusted so that the coolant passing through the heat exchanger has the same temperature. Thus, the two modules can work in a balanced manner and ensure that the output capacity is basically the same.

[0029] In addition, Figure 2 A variation can also be produced based on the battery heating mode. Figure 2 The difference is that the first heat exchanger can be coupled to the first condenser, so that the coolant absorbs heat from the first condenser and is heated, and the first heater 118 can assist in heating the coolant, so that the coolant can heat the battery. Similarly, the second heat exchanger can be coupled to the second condenser at this time, so that the coolant absorbs heat from the second condenser and is heated, and the second heater 118 also assists in heating the coolant.

[0030] Although at least one exemplary implementation has been described in the foregoing overview and detailed description, it should be appreciated that a large number of variations exist. It should also be appreciated that the exemplary implementation is merely illustrative and should not be considered as limiting in any way the scope, applicability, and configuration of the device according to the present invention. More specifically, the description of the specific implementation is intended to provide a professional with guidance for implementing at least one exemplary implementation, and various modifications may be made to the functionality and layout of the components described, as long as they do not deviate from the scope of protection determined by the claims and equivalent feature combinations.

Claims

1. A thermal management system for an electric truck, comprising: a first heat pump module, the first heat pump module comprising a first coolant circuit, a first refrigerant circuit, and a first module controller, A second heat pump module, the second heat pump module comprising a second coolant circuit, a second refrigerant circuit, and a second module controller, The first refrigerant circuit and the second refrigerant circuit are independent of each other, and the first refrigerant circuit is solely controlled by the first module controller, and the second refrigerant circuit is solely controlled by the second module controller, and the first coolant circuit and the second coolant circuit are connected in parallel, and the first coolant circuit and the second coolant circuit are symmetrically controlled by the first module controller and the second module controller, respectively.

2. The thermal management system according to claim 1, characterized in that: The first heat pump module and the second heat pump module are designed as identical heat pump modules.

3. The thermal management system according to claim 2, characterized in that: The thermal management system further includes at least one third heat pump module, and the third heat pump module is configured as the same heat pump module as the first heat pump module and the second heat pump module.

4. The thermal management system according to claim 1, characterized in that: The first coolant circuit comprises a first multi-way valve, a first pump and a first heat exchanger, the first refrigerant circuit comprises a first compressor, a first condenser, a first expansion valve and a first evaporator, wherein the first heat exchanger is coupled to the first condenser and / or the first evaporator, and the second coolant circuit comprises a second multi-way valve, a second pump and a second heat exchanger, the second refrigerant circuit comprises a second compressor, a second condenser, a second expansion valve and a second evaporator, wherein the second heat exchanger is coupled to the second condenser and / or the second evaporator.

5. The thermal management system according to claim 4, characterized in that: The first multi-way valve and the first pump are controlled by a first module controller, and the second multi-way valve and the second pump are controlled by a second module controller, wherein, according to target demand, the first module controller adjusts the opening of the first multi-way valve and the rotational speed of the first pump, and the second module controller adjusts the opening of the second multi-way valve and the rotational speed of the second pump, wherein the rotational speed of the first pump and the rotational speed of the second pump are adjusted so that the coolant flow of the first heat pump module and the second heat pump module is the same.

6. The thermal management system according to claim 5, characterized in that: 2 to 10 seconds before the first multi-way valve is switched, the speed of the first pump first drops to the minimum speed, and then returns to normal operation after the first multi-way valve is switched; similarly, 2 to 10 seconds before the second multi-way valve is switched, the speed of the second pump first drops to the minimum speed, and then returns to normal operation after the second multi-way valve is switched.

7. The thermal management system according to claim 4, characterized in that: The first compressor and the first expansion valve are controlled by a first module controller, and the second compressor and the second expansion valve are controlled by a second module controller, wherein, according to the same target requirements, the first module controller controls the speed of the first compressor and the opening of the first expansion valve, and the second module controller controls the speed of the second compressor and the opening of the second expansion valve.

8. The thermal management system according to claim 1, characterized in that: The thermal management system includes a battery thermal management subsystem, an electric drive and electronic control thermal management subsystem, an air-conditioning thermal management subsystem, a thermal management mode selection unit and a module capacity allocation unit, wherein the thermal management mode selection unit selects a thermal management mode according to the requirements of the battery thermal management subsystem, the electric drive and electronic control thermal management subsystem and the air-conditioning thermal management subsystem, and the module capacity allocation unit allocates output capacity to the first heat pump module through the first module controller according to the selected thermal management mode, and allocates output capacity to the second heat pump module through the second module controller.

9. The thermal management system according to claim 4, characterized in that: The first coolant circuit and the second coolant circuit are connected in parallel with the whole vehicle coolant circuit of the electric truck through a valve device, wherein the valve device is a three-way valve, wherein the whole vehicle coolant circuit includes a battery pack coolant circuit and an electric drive and electronic control coolant circuit, wherein the first multi-way valve and the second multi-way valve are respectively connected to the battery pack coolant circuit and / or the electric drive and electronic control coolant circuit.

10. An electric truck having a thermal management system according to any one of claims 1 to 9.

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