Electric motor coach heat management system and method for secondary loop heat exchange

Abstract

The invention discloses an electric motor coach heat management system and method for secondary loop heat exchange, the electric motor coach heat management system comprises a heat pump system, a cold water system, a hot water system, a battery temperature regulator and a cold and hot core body, the heat pump system is connected with the cold water system through an evaporator, and the heat pump system is connected with the hot water system through an air cooler; the cold water system comprises a cold water pump, a fan coil, an electric control and motor ATS cooling unit and a first secondary refrigerant loop communicated with all components. The hot water system comprises a hot water pump, a floor radiator, an outside-vehicle heat exchanger and a second refrigerating medium loop communicated with all the components. The battery temperature regulator and the cold and hot core body selectively communicate with the first secondary refrigerant loop or the second secondary refrigerant loop through valve switching. Independent cold and heat secondary loops are formed through the heat pump subsystem, the cold water subsystem and the hot water subsystem, efficient cold and heat distribution is achieved, and mutual interference is avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of thermal management of electric buses, and in particular relates to a thermal management system and method for electric buses with secondary circuit heat exchange. Background Art

[0002] With the rapid development of the new energy vehicle industry, electric buses, a crucial component of public transportation, face significant challenges in terms of range, safety, and passenger comfort. Electric buses must simultaneously meet the cooling and heating requirements of multiple components, including the battery, electronically controlled motor, passenger compartment, and cockpit. Traditional thermal management systems often utilize single circuits or discrete systems (e.g., independent cooling and heating systems), resulting in low efficiency, high energy consumption, and poor system integration.

[0003] Existing technologies use heat pump systems for cooling and heating in some electric buses. However, these systems often rely on a single heat exchange circuit, making it difficult to address the diverse thermal requirements of various components (e.g., precise battery temperature control and rapid passenger compartment temperature adjustment). Furthermore, traditional heat pump systems often use Freon-based refrigerants, which are environmentally inefficient. Furthermore, heating efficiency decreases significantly in low-temperature environments, requiring the use of PTC (positive temperature coefficient) thermistors (PTCs) for auxiliary heating, further increasing energy consumption. Furthermore, waste heat recovery from components such as batteries and electronically controlled motors is low, resulting in energy waste. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention proposes a thermal management system and method for an electric bus with secondary circuit heat exchange.

[0005] In order to achieve the above object, the technical solution of the present invention is as follows:

[0006] On the one hand, the present invention discloses a secondary circuit heat exchange thermal management system for electric buses, comprising: a heat pump system, a chilled water system, and a hot water system. The heat pump system comprises: a compressor, an air cooler, an evaporator, and a refrigerant circulation circuit connecting the various components. The heat pump system is connected to the chilled water system via the evaporator, and the heat pump system is connected to the hot water system via the air cooler.

[0007] The chilled water system includes: chilled water pump, fan coil unit, electric control and motor ATS cooling unit and the first refrigerant circuit connecting all components;

[0008] The fan coil unit is used to cool the passenger compartment, and the electronic control and motor ATS cooling unit is used to dissipate heat for the electronic control and motor;

[0009] The hot water system includes: a hot water pump, a floor radiator, an off-board heat exchanger, and a second coolant circuit connecting all components;

[0010] The floor radiator is used to heat the passenger compartment, and the off-board heat exchanger is used to discharge the heat generated by the hot water system to the outside environment;

[0011] The electric bus thermal management system also includes: a battery thermostat and a hot and cold core, which are selectively connected to the first coolant circuit or the second coolant circuit through valve switching. The battery thermostat is used to adjust the battery temperature, and the hot and cold core is used to adjust the cabin temperature.

[0012] The cooling energy generated by the evaporator of the heat pump system is transferred to the chilled water system through the primary refrigerant circuit, forming a secondary cooling circuit;

[0013] The heat generated by the air cooler of the heat pump system is transferred to the hot water system through the second refrigerant circuit, forming a secondary heat circuit;

[0014] The cooling secondary circuit and the heating secondary circuit work independently to realize the distribution of cooling and heating respectively.

[0015] On the basis of the above technical solution, the following improvements can be made:

[0016] As a preferred solution, the electric control and motor ATS cooling unit includes: electric control, motor, ATS circulation pump and ATS heat exchanger;

[0017] The electronic control and motor ATS cooling unit can be selectively connected to the first refrigerant circuit through valve switching to achieve hot and cold interaction with the refrigerant of the cold water system, and / or form an independent circulation pipeline to use its own ATS heat exchanger to discharge heat directly to the outside environment.

[0018] As a preferred solution, the cold water system further comprises: a refrigerator, the refrigerator being used to refrigerate items;

[0019] The hot water system also includes a high-temperature cabinet for heating items. As a preferred solution, the heat pump system uses CO2 as the refrigerant. The heat pump system includes a CO2 refrigeration compressor, an air cooler, a heat regenerator, a drying filter, an electronic expansion valve, an evaporator, and a liquid receiver.

[0020] The CO2 refrigeration compressor, air cooler, regenerator, filter drier, electronic expansion valve, evaporator, and liquid receiver are connected through pipelines to form a CO2 refrigerant circulation loop.

[0021] On the other hand, the present invention discloses a thermal management method for an electric bus with secondary circuit heat exchange, which uses any of the above-mentioned electric bus thermal management systems to achieve thermal management, specifically controlling the operation of the heat pump system according to different seasons.

[0022] As a preferred solution, in spring and autumn, the heat pump system is started for cooling, and the cooling energy generated by the evaporator is transferred to the chilled water system through the first refrigerant loop;

[0023] Switch the valve to connect the battery thermostat to the first coolant circuit, and open the corresponding valve of the cold water system to drive the coolant through the parallel cold cabinet and battery thermostat under the action of the cold water pump;

[0024] The electronic control and motor ATS cooling units are switched by valves to form independent circulation loops that are not connected to the primary coolant loop. The heat from the electronic control and motor is discharged directly to the outside environment using the ATS heat exchanger.

[0025] The heat generated by the air cooler is transferred to the hot water system through the second refrigerant circuit;

[0026] Open the corresponding valve of the hot water system and drive the coolant to flow through the parallel high-temperature cabinet and the off-board heat exchanger under the action of the hot water pump.

[0027] As a preferred solution, in summer, the heat pump system is started for cooling, and the cooling energy generated by the evaporator is transferred to the chilled water system through the first refrigerant loop;

[0028] Switching valves connects the battery thermostat and hot and cold cores to the first coolant circuit, respectively. Opening the corresponding valves in the cold water system drives the coolant through the parallel-connected refrigerator, battery thermostat, hot and cold cores, and fan coils under the action of the cold water pump. The electronic control and motor ATS cooling units are switched by valves to form independent circulation loops that are not connected to the first coolant circuit. Heat from the electronic control and motor is discharged directly to the outside environment using the ATS heat exchanger.

[0029] The heat generated by the air cooler is transferred to the hot water system through the second refrigerant circuit;

[0030] Open the corresponding valve of the hot water system and drive the coolant to flow through the parallel high-temperature cabinet and the off-board heat exchanger under the action of the hot water pump.

[0031] As a preferred solution, in extremely hot summer, the heat pump system is activated for cooling, and the cooling energy generated by the evaporator is transferred to the chilled water system through the first refrigerant circuit;

[0032] Switching valves to connect the battery thermostat and the hot and cold cores to the first coolant circuit respectively;

[0033] The electronic control and motor ATS cooling units are switched by valves, do not form independent circulation loops, and are connected to the first coolant loop. The heat from the electronic control and motor is discharged to the outside environment through the ATS heat exchanger.

[0034] Open the corresponding valve of the cold water system and drive the coolant to flow through the parallel cold cabinet, battery thermostat, hot and cold core, fan coil unit and electronic control and motor ATS cooling unit under the action of the cold water pump;

[0035] The heat generated by the air cooler is transferred to the hot water system through the second refrigerant circuit;

[0036] Open the corresponding valve of the hot water system and drive the coolant to flow through the parallel high-temperature cabinet and the off-board heat exchanger under the action of the hot water pump.

[0037] As a preferred solution, in winter, the heat pump system is started for heating;

[0038] Switching the valve to connect the battery thermostat to the first coolant circuit;

[0039] At the same time, the electronic control and motor ATS cooling units are switched through valves, not forming an independent circulation loop, but connected to the first coolant loop and connected in series with the battery thermostat to form a three-electric branch.

[0040] Open the corresponding valve of the cold water system to dissipate the heat of the three-electric branch through the ATS heat exchanger, and transfer the excess heat to the evaporator of the heat pump system through the first refrigerant loop, which serves as the low-temperature heat source of the heat pump system;

[0041] The heat generated by the air cooler is transferred to the hot water system through the second refrigerant circuit;

[0042] Switch the valve to connect the hot and cold cores to the second refrigerant circuit;

[0043] Open the corresponding valve of the hot water system to drive the coolant to flow through the parallel high-temperature cabinet, hot and cold core and floor radiator under the action of the hot water pump.

[0044] As a preferred solution, in severe winter, the heat pump system is started to generate heat;

[0045] The ATS cooling units for the electronic control and motor are switched by valves, forming independent circulation pipelines on the one hand, and using the ATS heat exchanger to discharge the heat of the electronic control and motor directly to the outside environment. At the same time, on the other hand, the ATS cooling units for the electronic control and motor are connected to the first refrigerant circuit, so that the heat generated by the electronic control and motor is dissipated through the ATS heat exchanger, and the excess heat is transferred to the evaporator of the heat pump system through the first refrigerant circuit, serving as the low-temperature heat source of the heat pump system.

[0046] The heat generated by the air cooler is transferred to the hot water system through the second refrigerant circuit;

[0047] Switching the valve connects the battery thermostat and the hot and cold core to the second coolant circuit;

[0048] Open the corresponding valve of the hot water system and drive the coolant to flow through the parallel high-temperature cabinet, hot and cold core, floor radiator and battery thermostat under the action of the hot water pump.

[0049] The present invention discloses a thermal management system and method for electric buses with secondary circuit heat exchange, which has the following beneficial effects:

[0050] First, the present invention forms independent secondary cooling and heating circuits through three subsystems: a heat pump, cold water, and hot water. This achieves efficient distribution of heat and cold, avoiding mutual interference. Core components can flexibly switch operating modes. For example, the battery thermostat and hot and cold cores can be connected to the cold / hot circuits via valves, precisely meeting the temperature control requirements of the battery and cabin. The electronic control and motor ATS cooling units can circulate independently or connect to the cold water system to adapt to different heat dissipation loads.

[0051] Secondly, the present invention integrates additional functions such as refrigeration (freezer) and heating (high-temperature cabinet), and utilizes the system's cold and heat to achieve energy reuse, saving space and cost.

[0052] Third, the present invention uses CO2 refrigerant, which is environmentally friendly and adaptable to high-temperature heating needs. It is combined with components such as a heat regenerator to improve the system's energy efficiency and stability.

[0053] Fourth, the present invention realizes flexible mode conversion through valve switching, so that the thermal management system can operate efficiently in different scenarios such as ultra-high temperature, severe cold, spring and autumn, etc., and realizes flexible mode conversion through valve switching, thereby improving the adaptability of buses in complex environments and comprehensively improving the energy saving, reliability and adaptability of the system under all working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0055] Figure 1 This is a block diagram of the electric bus thermal management system provided by an embodiment of the present invention.

[0056] Figure 2 This is a block diagram of the electric bus thermal management system (spring and autumn) provided by an embodiment of the present invention.

[0057] Figure 3 This is a block diagram of the electric bus thermal management system (summer) provided by an embodiment of the present invention.

[0058] Figure 4 This is a block diagram of the electric bus thermal management system (ultra-high temperature summer) provided by an embodiment of the present invention.

[0059] Figure 5 This is a block diagram of the electric bus thermal management system (winter) provided by an embodiment of the present invention.

[0060] Figure 6This is a block diagram of the electric bus thermal management system (for severe winter conditions) provided by an embodiment of the present invention.

[0061] in:

[0062] 1-Heat pump system, 11-CO2 refrigeration compressor, 12-Air cooler, 13-Regenerator, 14-Drying filter, 15-Electronic expansion valve, 16-Evaporator, 17-Liquid reservoir, 2-Cold water system, 21-Cold water pump, 22-Fan coil unit, 23-Electronic control and motor ATS cooling unit, 231-Electronic control, 232-Motor, 233-ATS circulation pump, 234-ATS heat exchanger, 235-ATS circulation pipeline, 24-Refrigerator, 3-Hot water system, 31-Hot water pump, 32-Floor radiator, 33-Outdoor heat exchanger, 34-High temperature cabinet, 4-Battery thermostat, 5-Cold and hot core. DETAILED DESCRIPTION

[0063] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0064] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0065] The expression “including” an element is an “open” expression. The “open” expression only means that the corresponding components or steps exist, and should not be interpreted as excluding additional components or steps.

[0066] In order to achieve the purpose of the present invention, some embodiments of a secondary circuit heat exchange electric bus thermal management system and method include: Figure 1 As shown, the thermal management system of an electric bus includes: a heat pump system 1, a cold water system 2 and a hot water system 3.

[0067] The heat pump system 1 includes: a compressor, an air cooler 12, an evaporator 16 and a refrigerant circulation circuit connecting the various components. The heat pump system 1 is connected to the cold water system 2 through the evaporator 16, and the heat pump system 1 is connected to the hot water system 3 through the air cooler 12.

[0068] The cold water system 2 includes: a cold water pump 21, a fan coil 22, an electronic control and motor ATS cooling unit 23, and a first refrigerant circuit connecting various components; the fan coil 22 is used to cool the passenger compartment, and the electronic control and motor ATS cooling unit 23 is used to dissipate heat for the electronic control 231 and the motor 232.

[0069] The hot water system 3 includes: a hot water pump 31, a floor radiator 32, an external heat exchanger 33, and a second coolant circuit connecting the various components; the floor radiator 32 is used to heat the passenger compartment, and the external heat exchanger 33 is used to discharge the heat generated by the hot water system 3 to the external environment.

[0070] The electric bus thermal management system also includes: a battery thermostat 4 and a hot and cold core 5. The battery thermostat 4 and the hot and cold core 5 are selectively connected to the first coolant circuit or the second coolant circuit through valve switching. The battery thermostat 4 is used to adjust the battery temperature, and the hot and cold core 5 is used to adjust the cabin temperature, such as the hot and cold core 5 at the windshield.

[0071] The cooling energy generated by the evaporator 16 of the heat pump system 1 is transferred to the chilled water system 2 through the first refrigerant loop, forming a secondary cooling energy loop; the heat generated by the air cooler 12 of the heat pump system 1 is transferred to the hot water system 3 through the second refrigerant loop, forming a secondary heat energy loop;

[0072] The cooling secondary circuit and the heating secondary circuit work independently to realize the distribution of cooling and heating respectively.

[0073] The valves involved in the thermal management system of an electric bus may be, but are not limited to, three-way reversing valves, flow regulating valves, and the like.

[0074] The present invention forms independent cooling / heating secondary circuits with the cold water system 2 and the hot water system 3 through the heat pump system 1, and the battery thermostat 4 and the cold and hot core 5 can selectively connect the two circuits through valve switching.

[0075] The cooling secondary circuit and the heating secondary circuit operate independently to avoid mutual interference between cooling and heating, thereby improving energy utilization efficiency. The battery thermostat 4 and the cooling and heating core 5 are flexibly connected to the cooling / heating circuits through valve switching, and can accurately adjust the temperature according to the real-time needs of the battery (which needs to maintain a suitable operating temperature) and the cockpit (which needs to meet the needs of passenger comfort), adapting to different working conditions.

[0076] In order to further optimize the implementation effect of the present invention, in some other embodiments, the remaining characteristic technologies are the same, the difference is that the electronic control and motor ATS cooling unit 23 includes: electronic control 231, motor 232, ATS circulation pump 233 and ATS heat exchanger 234.

[0077] The electronic control and motor ATS cooling unit 23 can be selectively connected to the first refrigerant circuit through valve switching to achieve hot and cold interaction with the refrigerant of the cold water system 2, and / or form an independent circulation pipeline to use its own ATS heat exchanger 234 to discharge heat directly to the outside environment.

[0078] With the above technical solution, the electric control and motor ATS cooling unit 23 uses the ATS circulation pipeline 235 to achieve independent circulation. This system clarifies the structure of the electric control and motor ATS cooling unit 23 and the function of "selectively connecting to the first coolant circuit or independent circulation".

[0079] The mode can be switched according to the real-time heat load of the electronic control 231 and the motor 232 (e.g., independent circulation to directly dissipate heat outside the vehicle at low load, and connection to the cold water system 2 to enhance heat dissipation by using cooling capacity at high load), thus avoiding energy waste;

[0080] The independent circulation mode can be used as a backup solution. When the cold water system 2 fails, it can still ensure the heat dissipation of the electronic control 231 and the motor 232, reducing the risk of system failure. When there is no need to rely on the cold water system 2, the heat is directly dissipated through its own ATS heat exchanger 234, reducing the intermediate energy transfer loss and improving the heat dissipation efficiency.

[0081] In order to further optimize the implementation effect of the present invention, in some other embodiments, the remaining characteristic technologies are the same, except that the cold water system 2 further includes: a refrigerator 24, which is used to refrigerate items;

[0082] The hot water system 3 further includes a high-temperature cabinet 34 , which is used for heating items.

[0083] By adopting the above technical solution, a new freezer 24 (refrigeration) and a high-temperature cabinet 34 (heating) are added to expand the system function.

[0084] Integrating refrigeration and heating functions based on thermal management to meet the bus's needs for refrigeration (such as fresh produce and medicine) and heating (such as hot water and meals) of food and items without the need for additional independent equipment;

[0085] The refrigerator 24 utilizes the cooling capacity of the cold water system 2, and the high-temperature cabinet 34 utilizes the heat of the hot water system 3, realizing secondary energy utilization and reducing overall energy consumption; the integrated functions reduce equipment redundancy, lower procurement and installation costs, and save limited space in the bus.

[0086] In order to further optimize the implementation effect of the present invention, in some other embodiments, the remaining characteristic technologies are the same, except that the heat pump system 1 uses CO2 as the refrigerant.

[0087] Furthermore, the heat pump system includes: a CO2 refrigeration compressor 11, an air cooler 12, a regenerator 13, a drying filter 14, an electronic expansion valve 15, an evaporator 16, and a liquid reservoir 17;

[0088] The CO2 refrigeration compressor 11, the air cooler 12, the regenerator 13, the drying filter 14, the electronic expansion valve 15, the evaporator 16, and the liquid storage tank 17 are connected through pipelines to form a CO2 refrigerant circulation loop.

[0089] Using this technical solution, heat pump system 1 uses CO2 as a refrigerant, and the CO2 refrigerant circuit is physically isolated from the coolant circuits of chilled water system 2 and hot water system 3. As a natural refrigerant, CO2 is non-flammable and non-explosive, fundamentally eliminating the flammability and explosion risks and environmental issues associated with traditional refrigerants (such as Freon).

[0090] The physical isolation design ensures that the CO2 high-pressure refrigerant circulates only within the heat pump system 1, reducing direct contact with the vehicle cabin and three-electric components. The CO2 charge volume can also be significantly reduced (due to the independent and compact circuit), further reducing the risk of leakage and improving vehicle safety.

[0091] The refrigerant circulates only in an independent refrigerant circuit and is physically isolated from the coolant circuit. There is no need to adapt to the huge pipelines of the cold water and hot water systems 3, which greatly reduces the charge volume, reduces the probability of leakage and the safety risks after leakage, and significantly improves system safety.

[0092] In other embodiments, the present invention discloses a thermal management method for an electric bus with secondary circuit heat exchange, which implements thermal management using the electric bus thermal management system disclosed in any of the above embodiments, specifically controlling the operation of the heat pump system 1 according to different seasons.

[0093] The present invention adjusts the heat pump operation mode by matching seasonal characteristics, avoiding energy waste caused by "one-size-fits-all" operation; ensuring that the system can maintain high efficiency under the load requirements of different seasons, thereby reducing overall energy consumption.

[0094] The following is a detailed introduction to the operating mode of each season. Figure 2-6 As shown in the figure, the blue pipe is the cooling secondary circuit, the red pipe is the heating secondary circuit, and the arrow direction is the refrigerant flow direction. The dotted line pipe indicates that the pipe is blocked in this mode.

[0095] Further, if Figure 2 As shown, in spring and autumn (e.g., 15°C-25°C), the heat pump system 1 is started for cooling, and the cooling energy generated by the evaporator 16 is transferred to the chilled water system 2 through the first refrigerant circuit;

[0096] Switching valves connects the battery thermostat 4 to the first brine circuit, and opening the corresponding valve of the cold water system 2 drives the brine to flow through the parallel-connected refrigerator 24 and the battery thermostat 4 under the action of the cold water pump 21. The electronic control and motor ATS cooling unit 23 forms an independent circulation loop through the valve switching and is not connected to the first brine circuit. The heat of the electronic control 231 and motor 232 is directly discharged to the outside environment through the ATS heat exchanger 234. (At this time, valve R2 is closed, and the brine, under the action of the ATS circulation pump, transfers the heat generated by the electronic control and motor through the ATS circulation pipeline and discharges it to the outside of the vehicle through the ATS heat exchanger.)

[0097] The heat generated by the air cooler 12 is transferred to the hot water system 3 through the second coolant circuit;

[0098] The corresponding valve of the hot water system 3 is opened, and the brine is driven to flow through the high-temperature cabinet 34 and the off-vehicle heat exchanger 33 connected in parallel under the action of the hot water pump 31 .

[0099] In summary, in the spring and autumn operating modes, the heat pump system 1 is used for cooling, the battery thermostat 4 is connected to the cold water system 2, the electronic control and motor ATS cooling unit 23 dissipates heat independently, and the heat from the hot water system 3 is supplied to the high-temperature cabinet 34 and discharged outside the vehicle.

[0100] The demand for cooling and heating is lower in spring and autumn. By using the "battery + freezer" in parallel for cooling and the "high-temperature cabinet + external heat exchanger" in parallel for heat dissipation, energy can be accurately distributed to avoid overload.

[0101] The electronic control and motor ATS cooling unit 23 dissipates heat independently to reduce dependence on the cold water system 2, and the excess heat from the hot water system 3 is directly discharged to avoid ineffective energy consumption.

[0102] Further, if Figure 3 As shown, in summer (e.g., 25°C-35°C), the heat pump system 1 is started for cooling, and the cooling energy generated by the evaporator 16 is transferred to the chilled water system 2 through the first refrigerant circuit;

[0103] Switch the valves to connect the battery thermostat 4 and the hot and cold core 5 to the first coolant circuit respectively, and open the corresponding valves of the cold water system 2 to drive the coolant to flow through the parallel-connected refrigerator 24, the battery thermostat 4, the hot and cold core 5, and the fan coil 22 under the action of the cold water pump 21;

[0104] The electronic control and motor ATS cooling unit 23 is switched by a valve to form an independent circulation loop, which is not connected to the first brine loop. The heat of the electronic control 231 and motor 232 is directly discharged to the outside environment through the ATS heat exchanger 234. (At this time, valve R2 is closed, and the brine, under the action of the ATS circulation pump, passes through the ATS circulation pipeline to discharge the heat generated by the electronic control and motor to the outside of the vehicle through the ATS heat exchanger.)

[0105] The heat generated by the air cooler 12 is transferred to the hot water system 3 through the second coolant circuit;

[0106] The corresponding valve of the hot water system 3 is opened, and the brine is driven to flow through the high-temperature cabinet 34 and the off-vehicle heat exchanger 33 connected in parallel under the action of the hot water pump 31 .

[0107] In summary, in the summer operation mode, the heat pump system 1 performs cooling, and the cold capacity is supplied to the cold cabinet 24, the battery thermostat 4, the hot and cold core 5, and the fan coil 22. The electronic control and motor ATS cooling unit 23 dissipates heat independently, and the hot water system 3 supplies heat to the high-temperature cabinet 34 and discharges it outside the vehicle.

[0108] In this mode, centralized cooling is supplied to the passenger compartment (fan coil 22), cockpit (cold and hot core 5), batteries (to prevent failure due to high temperature) and refrigerator 24 (to maintain refrigeration), fully ensuring the comfort of all components and passengers in summer;

[0109] Multiple components are connected in parallel to the cold water system 2, and the cooling capacity is evenly distributed. At the same time, the heat dissipation load of the electric control 231 and the motor 232 is shared by the electric control and motor ATS cooling unit 23 to avoid overload of the cold water system 2.

[0110] The fan coil unit 22 and the hot and cold core 5 respectively adjust the temperature of the passenger compartment and the cockpit in a targeted manner to meet the comfort requirements of different areas.

[0111] Further, if Figure 4 As shown, in extremely high summer temperatures (e.g., above 35°C), the heat pump system 1 is started for cooling, and the cooling energy generated by the evaporator 16 is transferred to the chilled water system 2 through the first refrigerant circuit;

[0112] Switch the valves to connect the battery thermostat 4 and the hot and cold core 5 to the first coolant circuit respectively;

[0113] The electronic control and motor ATS cooling unit 23 is switched by a valve, does not form an independent circulation loop, and is connected to the first coolant loop, using the ATS heat exchanger to discharge the heat of the electronic control and motor to the outside environment (at this time, valve R2 is open);

[0114] Open the corresponding valve of the cold water system 2, and drive the coolant to flow through the parallel cold cabinet 24, battery thermostat 4, hot and cold core 5, fan coil 22 and electronic control and motor ATS cooling unit 23 under the action of the cold water pump;

[0115] The heat generated by the air cooler 12 is transferred to the hot water system through the second coolant circuit;

[0116] The corresponding valve of the hot water system 3 is opened, and the brine is driven to flow through the high-temperature cabinet 34 and the off-vehicle heat exchanger 33 connected in parallel under the action of the hot water pump 31 .

[0117] In summary, in the ultra-high temperature summer operation mode: the heat pump system 1 cools, and the cold capacity is supplied to the cold cabinet 24, the battery thermostat 4, the hot and cold core 5, the fan coil 22, and the electronic control and motor ATS cooling unit 23; the hot water system 3 supplies heat to the high temperature cabinet 34 and is discharged outside the vehicle.

[0118] In this mode, centralized cooling is supplied to the passenger compartment (fan coil 22), cockpit (hot and cold core 5), battery (to avoid failure due to high temperature), refrigerator 24 (to maintain refrigeration), and electronic control and motor ATS cooling unit, ensuring the comfort of all components and passengers in summer.

[0119] Multiple components are connected in parallel to chiller system 2, ensuring even cooling capacity distribution. In extremely high temperatures (when ambient temperatures approach or exceed the operating temperature of the electronic control motor), the ATS heat exchanger's efficiency in dissipating heat to the outside of the vehicle decreases significantly, making independent circulation insufficient. Introducing cooling capacity from the evaporator through the R2 regulating valve directly lowers the refrigerant temperature, significantly improving cooling efficiency for the electronic control motor and preventing performance degradation or damage due to excessive temperatures.

[0120] The parallel structure allows the electronic motor and battery to regulate temperature independently or collaboratively. For example, if the battery temperature is normal but the electronic motor is overheating, cooling can be added to the electronic motor branch alone to achieve precise temperature control.

[0121] Further, if Figure 5 As shown, in winter (e.g., -5°C to 15°C), the heat pump system 1 is started for heating;

[0122] Switch the valve to connect the battery thermostat 4 to the first coolant circuit;

[0123] At the same time, the electronic control and motor ATS cooling unit 23 is also connected to the first coolant circuit through valve switching, and is connected in series with the battery thermostat 4 to form a three-electric branch (at this time, valve R2 is closed, and the battery thermostat, electronic control, and motor are connected in series, transferring the heat generated by the electronic control and motor to the battery thermostat to keep the battery warm).

[0124] Open the corresponding valve of the chilled water system 2, so that the heat of the three-electric branch is dissipated by the ATS heat exchanger, and the excess heat is transferred to the evaporator of the heat pump system through the first refrigerant loop, which serves as the low-temperature heat source of the heat pump system;

[0125] The heat generated by the air cooler 12 is transferred to the hot water system 3 through the second coolant circuit;

[0126] Switch the valve to connect the hot and cold core 5 to the second refrigerant circuit;

[0127] The corresponding valve of the hot water system 3 is opened to drive the coolant to flow through the parallel high-temperature cabinet 34, the hot and cold core 5 and the floor radiator 32 under the action of the hot water pump 31.

[0128] In summary, in winter operation mode: the heat pump system 1 generates heat, the battery thermostat 4 and the electronic control and motor ATS cooling unit 23 are connected in series, and the heat of the hot water system 3 is supplied to the high-temperature cabinet 34, the hot and cold core 5, and the floor radiator 32.

[0129] In winter, the series connection forms a "three-electric branch" to dissipate heat while transferring heat generated by the electronic control and motor to the battery thermostat, preventing battery damage from low temperatures. Hot water system 3 supplies heat to the passenger compartment (floor radiator 32), cockpit (heat and cool core 5), and high-temperature cabinet 34.

[0130] The floor radiator 32 (heating), the hot and cold core 5 (cockpit), and the high temperature cabinet 34 (heating) use heat in parallel, so that the heat is distributed reasonably and the heat loss is reduced.

[0131] The battery thermostat 4 maintains the battery at a suitable temperature through the cold water system 2 to avoid capacity decay at low temperatures, while the cabin heating meets comfort requirements.

[0132] Further, if Figure 6 As shown, in severe winter (e.g. below -5°C), the heat pump system 1 is started for heating;

[0133] The electronic control and motor ATS cooling unit 23 is switched by a valve. On the one hand, it forms an independent circulation pipeline, using the ATS heat exchanger 234 to directly discharge the heat of the electronic control 231 and motor 232 to the vehicle environment. At the same time, on the other hand, the electronic control and motor ATS cooling unit 23 is connected to the first refrigerant circuit, so that the heat generated by the electronic control 231 and motor 232 is dissipated through the ATS heat exchanger, and the excess heat is transferred to the evaporator 16 of the heat pump system 1 through the first refrigerant circuit, serving as a low-temperature heat source for the heat pump system 1 (at this time, valve R2 is open).

[0134] The heat generated by the air cooler 12 is transferred to the hot water system 3 through the second coolant circuit;

[0135] Switch the valve to connect the battery thermostat 4 and the hot and cold core 5 to the second coolant circuit;

[0136] Open the corresponding valve of the hot water system 3 and drive the coolant to flow through the parallel high-temperature cabinet 34, the hot and cold core 5, the floor radiator 32 and the battery thermostat 4 under the action of the hot water pump 31.

[0137] In summary, in severe winter mode: the electronic control and motor ATS cooling unit 23 both independently dissipates heat and supplies waste heat to the evaporator 16, and the hot water system 3 fully heats key components.

[0138] The waste heat of the electric control 231 and the motor 232 is transferred to the evaporator 16 through the first refrigerant circuit as a low-temperature heat source for the heat pump, thereby reducing the energy consumption of the heat pump absorbing heat from the low-temperature environment and reducing the dependence on auxiliary heating such as PTC.

[0139] The hot water system 3 simultaneously supplies heat to the high-temperature cabinet 34, the hot and cold core 5, the floor radiator 32, and the battery thermostat 4, ensuring the heating needs of the battery (to avoid low-temperature failure), the cabin (for comfort), and items in severe cold weather, thereby improving the system's cold resistance.

[0140] The electronic control and motor ATS cooling unit 23 has a dual mode of "independent heat dissipation + waste heat utilization", which not only prevents the electronic control 231 and the motor 232 from overheating, but also fully recovers energy, taking into account both safety and energy saving.

[0141] The present invention discloses a thermal management system and method for electric buses with secondary circuit heat exchange, which has the following beneficial effects:

[0142] First, the present invention forms independent secondary cooling and heating circuits through the heat pump, cold water, and hot water subsystems, achieving efficient distribution of heat and cold, while avoiding mutual interference. Core components can flexibly switch operating modes. For example, the battery thermostat 4 and the hot and cold core 5 can be connected to the cold / hot circuit via valves, precisely meeting the temperature control requirements of the battery and cabin. The electronic control and motor ATS cooling unit 23 can circulate independently or connect to the cold water system 2 to adapt to different heat dissipation loads.

[0143] Second, the present invention integrates additional functions such as refrigeration (freezer 24) and heating (high-temperature cabinet 34), and utilizes the system's cold and heat to achieve energy reuse, saving space and cost.

[0144] Third, the present invention uses CO2 refrigerant, which is environmentally friendly and adaptable to high-temperature heating needs, and is combined with components such as the heat regenerator 13 to improve the system energy efficiency and stability.

[0145] Fourth, the present invention realizes flexible mode conversion through valve switching, so that the thermal management system can operate efficiently in different scenarios such as ultra-high temperature, severe cold, spring and autumn, etc., and realizes flexible mode conversion through valve switching, thereby improving the adaptability of buses in complex environments and comprehensively improving the energy saving, reliability and adaptability of the system under all working conditions.

[0146] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which shall fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. The electric bus thermal management system with secondary circuit heat exchange is characterized by: include: A heat pump system, a chilled water system, and a hot water system. The heat pump system includes a compressor, an air cooler, an evaporator, and a refrigerant circulation loop connecting the various components. The heat pump system is connected to the chilled water system via the evaporator, and the heat pump system is connected to the hot water system via the air cooler. The chilled water system includes: a chilled water pump, a fan coil unit, an electric control and motor ATS cooling unit, and a first coolant circuit connecting the various components; The fan coil unit is used to cool the passenger compartment, and the electric control and motor ATS cooling unit is used to dissipate heat for the electric control and motor; The hot water system includes: a hot water pump, a floor radiator, an off-board heat exchanger, and a second coolant circuit connecting the various components; The floor radiator is used to heat the passenger compartment, and the external heat exchanger is used to discharge the heat generated by the hot water system to the external environment; The electric bus thermal management system further includes: a battery thermostat and a hot and cold core, wherein the battery thermostat and the hot and cold core are selectively connected to the first coolant circuit or the second coolant circuit respectively through valve switching, the battery thermostat is used to adjust the battery temperature, and the hot and cold core is used to adjust the cabin temperature; The cooling energy generated by the evaporator of the heat pump system is transferred to the chilled water system through the first refrigerant circuit to form a secondary cooling energy circuit; The heat generated by the air cooler of the heat pump system is transferred to the hot water system through the second refrigerant circuit to form a secondary heat circuit; The cooling secondary circuit and the heating secondary circuit work independently to realize the distribution of cooling and heating respectively.

2. The electric bus thermal management system according to claim 1, characterized in that: The electronic control and motor ATS cooling unit includes: electronic control, motor, ATS circulation pump and ATS heat exchanger; The electronic control and motor ATS cooling unit can be selectively connected to the first refrigerant circuit through valve switching to achieve hot and cold interaction with the refrigerant of the cold water system, and / or form an independent circulation pipeline to use its own ATS heat exchanger to discharge heat directly to the outside environment.

3. The electric bus thermal management system according to claim 1, characterized in that: The cold water system further comprises: a refrigerator, wherein the refrigerator is used to refrigerate items; The hot water system further comprises a high temperature cabinet, which is used for heating items.

4. The electric bus thermal management system according to claim 1, characterized in that: The heat pump system uses CO2 as refrigerant and includes: a CO2 refrigeration compressor, an air cooler, a regenerator, a drying filter, an electronic expansion valve, an evaporator, and a liquid receiver; The CO2 refrigeration compressor, air cooler, regenerator, drying filter, electronic expansion valve, evaporator and liquid storage are connected through pipelines to form a CO2 refrigerant circulation loop.

5. A thermal management method for electric buses with secondary circuit heat exchange, characterized in that: Thermal management is achieved by using the thermal management system for an electric bus as described in any one of claims 1 to 4, specifically controlling the operation of the heat pump system according to different seasons.

6. The electric bus thermal management method according to claim 5, characterized in that: In spring and autumn, the heat pump system is started for cooling, and the cooling capacity generated by the evaporator is transferred to the chilled water system through the first refrigerant loop; Switch the valve to connect the battery thermostat to the first coolant circuit, and open the corresponding valve of the cold water system to drive the coolant through the parallel cold cabinet and battery thermostat under the action of the cold water pump; The electronic control and motor ATS cooling units are switched by valves to form independent circulation loops that are not connected to the primary coolant loop. The heat from the electronic control and motor is discharged directly to the outside environment using the ATS heat exchanger. The heat generated by the air cooler is transferred to the hot water system through the second refrigerant circuit; Open the corresponding valve of the hot water system and drive the coolant to flow through the parallel high-temperature cabinet and the off-board heat exchanger under the action of the hot water pump.

7. The electric bus thermal management method according to claim 5, characterized in that: In summer, the heat pump system is started for cooling, and the cooling capacity generated by the evaporator is transferred to the chilled water system through the first refrigerant loop; Switch the valves to connect the battery thermostat and the hot and cold cores to the first coolant circuit respectively, and open the corresponding valves of the cold water system to drive the coolant to flow through the parallel-connected refrigerator, battery thermostat, hot and cold cores, and fan coil units under the action of the cold water pump; The electronic control and motor ATS cooling units are switched by valves to form independent circulation loops that are not connected to the primary coolant loop. The heat from the electronic control and motor is discharged directly to the outside environment using the ATS heat exchanger. The heat generated by the air cooler is transferred to the hot water system through the second refrigerant circuit; Open the corresponding valve of the hot water system and drive the coolant to flow through the parallel high-temperature cabinet and the off-board heat exchanger under the action of the hot water pump.

8. The electric bus thermal management method according to claim 5, characterized in that: In extremely hot summer, the heat pump system is started for cooling, and the cooling capacity generated by the evaporator is transferred to the chilled water system through the first refrigerant loop; Switching valves to connect the battery thermostat and the hot and cold cores to the first coolant circuit respectively; The electronic control and motor ATS cooling units are switched by valves, do not form independent circulation loops, and are connected to the first coolant loop. The heat from the electronic control and motor is discharged to the outside environment through the ATS heat exchanger. Open the corresponding valve of the cold water system and drive the coolant to flow through the parallel cold cabinet, battery thermostat, hot and cold core, fan coil unit and electronic control and motor ATS cooling unit under the action of the cold water pump; The heat generated by the air cooler is transferred to the hot water system through the second refrigerant circuit; Open the corresponding valve of the hot water system and drive the coolant to flow through the parallel high-temperature cabinet and the off-board heat exchanger under the action of the hot water pump.

9. The electric bus thermal management method according to claim 5, characterized in that: In winter, start the heat pump system for heating; Switching the valve to connect the battery thermostat to the first coolant circuit; At the same time, the electronic control and motor ATS cooling units are switched through valves, not forming an independent circulation loop, but connected to the first coolant loop and connected in series with the battery thermostat to form a three-electric branch. Open the corresponding valve of the cold water system to dissipate the heat of the three-electric branch through the ATS heat exchanger, and transfer the excess heat to the evaporator of the heat pump system through the first refrigerant loop, which serves as the low-temperature heat source of the heat pump system; The heat generated by the air cooler is transferred to the hot water system through the second refrigerant circuit; Switch the valve to connect the hot and cold cores to the second refrigerant circuit; Open the corresponding valve of the hot water system to drive the coolant to flow through the parallel high-temperature cabinet, hot and cold core and floor radiator under the action of the hot water pump.

10. The thermal management method for electric buses according to claim 5, characterized in that: In severe winter, start the heat pump system for heating; The ATS cooling units for the electronic control and motor are switched by valves, forming independent circulation pipelines on the one hand, and using the ATS heat exchanger to discharge the heat of the electronic control and motor directly to the outside environment. At the same time, on the other hand, the ATS cooling units for the electronic control and motor are connected to the first refrigerant circuit, so that the heat generated by the electronic control and motor is dissipated through the ATS heat exchanger, and the excess heat is transferred to the evaporator of the heat pump system through the first refrigerant circuit, serving as the low-temperature heat source of the heat pump system. The heat generated by the air cooler is transferred to the hot water system through the second refrigerant circuit; Switching the valve connects the battery thermostat and the hot and cold core to the second coolant circuit; Open the corresponding valve of the hot water system and drive the coolant to flow through the parallel high-temperature cabinet, hot and cold core, floor radiator and battery thermostat under the action of the hot water pump.

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