A thermal management system and a coolant filling strategy for a hybrid vehicle

Abstract

The application discloses a heat management system of a hybrid vehicle, comprising a high-temperature cooling system, a low-temperature cooling system and a battery cooling system which are communicated through pipelines, wherein the high-temperature cooling system comprises an engine, a high-temperature radiator, a proportional three-way valve I, a proportional three-way valve II, a heater, a heat exchanger, a high-pressure heater, an electronic water pump I and an expansion tank I, the low-temperature cooling system and the battery cooling system share an expansion tank II, the expansion tank I and the expansion tank II are arranged at a filling port of vehicle coolant, and play a role of liquid storage and accumulation and balance the operating pressure of the cooling system during operation of the cooling system. Through the arrangement of the heat management system, the cooling system circuit can be ensured to be unobstructed by water valves and other components during manual filling of the coolant, and the filling amount of the coolant during the manual filling process can meet the requirements of the target setting. The application further provides a coolant filling strategy for the hybrid vehicle.

Description

Technical Field

[0001] This invention belongs to the field of automotive thermal management technology, specifically relating to a thermal management system and coolant filling strategy for hybrid vehicles. Background Technology

[0002] There are generally two scenarios for adding coolant to passenger vehicles: during the vehicle manufacturing process and during after-sales maintenance. During manufacturing, dedicated equipment is typically used to add coolant through a vacuum system connected to the vehicle's cooling system's expansion tank. During after-sales maintenance, coolant is usually added manually through the expansion tank inlet.

[0003] If a dedicated refilling device is used, the filler gun will remove air from the entire cooling system and check the system's seal before adding coolant. However, during after-sales maintenance, vehicle refilling relies on the coolant's own weight and the cooling system's venting mechanism to remove air. Generally, after refilling, the vehicle needs to stand for a period of time (some vehicles even require starting the engine to allow the engine water pump to circulate the coolant) to check the expansion tank level and consider adding more coolant later.

[0004] For traditional gasoline vehicles, the cooling system has a relatively simple structure and low resistance, so manual refilling is usually sufficient for after-sales maintenance. However, for hybrid vehicles, the number of cooling components and connecting pipes increases, and due to space constraints, the system piping is more complex. The system's own degassing structure struggles to completely remove all air from the cooling system. Furthermore, the cooling system of hybrid vehicles typically connects multiple valves of different structures, and the opening and closing of these valves directly affects the connection or closure of the cooling system circuit, which is also a significant factor affecting coolant filling. When manually adding coolant to a hybrid vehicle, the coolant level can drop after prolonged periods of inactivity (due to the slow expulsion of air from the system), resulting in less coolant than the target amount. In such cases, if the vehicle is driven aggressively, it can easily lead to powertrain overheating and other malfunctions, and in severe cases, even vehicle breakdown.

[0005] Chinese invention patent application CN202111451293, published on May 13, 2022, provides an auxiliary device for adding coolant to new energy vehicles. This device, related to the field of new energy vehicles, can improve the speed of adding coolant to cryogenic circuits, while being low-cost, compact, and suitable for adding coolant in non-factory locations. The auxiliary device includes a housing, a piston, and a drive unit. The housing contains a cavity with a filling port and a pressure relief port. The filling port connects the cavity to the degassing chamber of the vehicle's cooling system, while the pressure relief port connects the cavity to the outside. The piston is disposed within the cavity and is slidably sealed to the inner wall of the cavity. The drive unit drives the piston to slide along the inner wall of the cavity between a first position and a second position. The filling port is located outside the first and second positions, and the pressure relief port is located between the first and second positions. However, the technical solution of this patent still fails to solve the technical problem of this application. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a thermal management system and coolant filling strategy for hybrid vehicles. This ensures that the cooling system circuit remains unobstructed during manual coolant filling, without obstruction from components such as water valves. It also guarantees that the amount of coolant added during manual filling meets the target requirements, thus solving the problem in existing technologies where the actual amount of coolant added to hybrid vehicles is less than the target amount when manually adding coolant.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows: a thermal management system for a hybrid vehicle, comprising a high-temperature cooling system, a low-temperature cooling system, and a battery cooling system connected by pipelines. The high-temperature cooling system includes an engine, a high-temperature radiator, a proportional three-way valve I, a proportional three-way valve II, a heater, a heat exchanger, a high-pressure heater, an electric water pump I, and an expansion tank I. The low-temperature cooling system and the battery cooling system share an expansion tank II. The expansion tank I and the expansion tank II are located at the vehicle's coolant filling port, serving to store and accumulate coolant, and also to balance the operating pressure of the cooling system during operation.

[0008] Furthermore, the cryogenic cooling system includes a water-cooled intercooler, an electronic water pump II, a vehicle electric drive system controller, an inverter, and a cryogenic radiator, which are connected by pipelines.

[0009] Furthermore, the battery cooling system includes a battery, a battery cooler, a heat exchanger, and an electronic water pump III, which are connected by pipelines.

[0010] Furthermore, the electronic water pump I is an H_Ewp water pump, which is an electronic water pump that drives both heating and battery heating functions; the electronic water pump II is a P_Ewp water pump, which is used to drive the circulation of the WCAC, MCU and CCU cooling systems; and the electronic water pump III is a B_Ewp water pump, which is a water pump for the battery cooling system.

[0011] Furthermore, expansion tanks I and II are located at the highest point of the vehicle's coolant system in the Z direction. During the filling process, the covers of expansion tanks I and II are opened, and coolant is added. The liquid will flow to the bottom due to gravity.

[0012] This invention also relates to a coolant filling strategy for hybrid vehicles. Based on the aforementioned thermal management system for hybrid vehicles, the coolant filling strategy execution steps include:

[0013] Step 1. Open the covers of expansion tank I and expansion tank II, and at the same time unscrew the air leak cap on the pipeline, and statically add coolant;

[0014] Step 2. Wake up the vehicle and put it in the high-pressure Ready state. With the vehicle in P gear, use the vehicle's infotainment system air conditioning interface (AIPM) to simultaneously press and hold the Auto button and the rear defrost button for 5 seconds to wake up the air conditioning controller CLM and the engine control unit ECU.

[0015] Step 3. The engine control unit (ECU) drives the P_Ewp water pump to operate;

[0016] Step 4. The CLM drives the battery cooling system water pump B_Ewp to operate;

[0017] Step 5. For the control strategy of the high-temperature cooling system, the ECU and CLM need to work together to control it;

[0018] Step 6. After the timing in steps 2-5 is completed, the refueling function is finished.

[0019] Step 7. The above steps can be repeated to achieve the function of multiple filling and venting. The final filling effect is observed until the liquid levels in expansion tank I and expansion tank II are between the Max line and the Min line and no longer change.

[0020] Furthermore, during the static addition of coolant in step 1, ensure that the coolant level is between the Max and Min lines, remain still and observe that the level does not drop within 10 minutes; at the same time, when coolant overflows from the air leak cap, screw on the air leak cap.

[0021] Furthermore, the specific operation of the coordinated control by the ECU and CLM in step 5 is as follows: The following sequential control is performed on the four actuators: proportional three-way valve II, proportional three-way valve I, E_Ewp, H_Ewp, and Thermostat, with timing management: STEP 1: Set the flow direction of proportional three-way valve II to 1→2, the angle opening to 90°, and the water valve motor drive duty cycle to 33.33%; set the flow direction of proportional three-way valve I to 1→3, the angle opening to 240°, and the water valve motor drive duty cycle to 88.88%; set the speed of E_Ewp to 1500 rpm, set H_Ewp to the Off state, and the Thermostat to the On state, and start timing for 120 seconds.

[0022] STEP 2: Set the flow direction of proportional three-way valve II to 1→2, the opening angle to 90°, and the water valve motor drive duty cycle to 33.33%; set the flow direction of proportional three-way valve I to 1→2, the opening angle to 90°, and the water valve motor drive duty cycle to 33.33%; set the speed of E_Ewp to 1500rpm, set H_Ewp to Off, put the Thermostat on, and start timing for 120 seconds;

[0023] STEP 3: Set the flow direction of proportional three-way valve II to 1→2, the opening angle to 90°, and the water valve motor drive duty cycle to 33.33%; set the flow direction of proportional three-way valve I to 1→2&3, the opening angle to 180°, and the water valve motor drive duty cycle to 66.66%; set the speed of E_Ewp to 3000rpm, set H_Ewp to Off, put the Thermostat on, and start timing for 180 seconds;

[0024] STEP 4: Set the flow direction of proportional three-way valve II to 1→2&3, the angle opening to 180°, and the water valve motor drive duty cycle to 66.66%; set the flow direction of proportional three-way valve I to 1→2&3, the angle opening to 180°, and the water valve motor drive duty cycle to 66.66%; set the speed of E_Ewp to 3000rpm, set H_Ewp to Off, set the Thermostat to On, and start timing for 120 seconds;

[0025] STEP 5: Set the flow direction of proportional three-way valve II to 3→2, the angle opening to 0°, and the water valve motor drive duty cycle to 0%; set the flow direction of proportional three-way valve I to 1→2&3, the angle opening to 180°, and the water valve motor drive duty cycle to 66.66%; set E_Ewp to Off state, H_Ewp duty cycle to 50%, Thermostat to On state, and time for 60 seconds; through the linear relationship between duty cycle and speed, it can be seen that a 50% duty cycle of H_Ewp corresponds to a speed of 2950 rpm for H_Ewp;

[0026] STEP 6: Set the flow direction of proportional three-way valve II to 3→2, the angle opening to 0°, and the water valve motor drive duty cycle to 0%; set the flow direction of proportional three-way valve I to 1→3, the angle opening to 240°, and the water valve motor drive duty cycle to 88.88%; set the speed of E_Ewp to 4000rpm, set the duty cycle of H_Ewp to 75%, and put the Thermostat in the open state and start timing for 60 seconds; through the linear relationship between duty cycle and speed, it can be seen that a 75% duty cycle of H_Ewp corresponds to a speed of 4770rpm for H_Ewp;

[0027] STEP 7: Set the flow direction of proportional three-way valve II to 3→2, the angle opening to 0°, and the water valve motor drive duty cycle to 0%; set the flow direction of proportional three-way valve I to 1→2, the angle opening to 90°, and the water valve motor drive duty cycle to 33.33%; set the speed of E_Ewp to 4000rpm, set the duty cycle of H_Ewp to 75%, the Thermostat to be on, and start timing for 60 seconds; through the linear relationship between duty cycle and speed, it can be seen that a 75% duty cycle of H_Ewp corresponds to a speed of 4770rpm for H_Ewp;

[0028] STEP 8: Set the flow direction of proportional three-way valve II to 1→2&3, the angle opening to 180°, and the water valve motor drive duty cycle to 66.6%; set the flow direction of proportional three-way valve I to 1→2&3, the angle opening to 180°, and the water valve motor drive duty cycle to 66.6%; set the speed of E_Ewp to 4000rpm, set H_Ewp to Off state, put the Thermostat in the on state, and start timing for 180 seconds;

[0029] STEP 9: Set the flow direction of proportional three-way valve II to 1→2&3, the angle opening to 180°, and the water valve motor drive duty cycle to 66.6%; set the flow direction of proportional three-way valve I to 1→2&3, the angle opening to 180°, and the water valve motor drive duty cycle to 66.6%; set both E_Ewp and H_Ewp to Off state, and the Thermostat to On state.

[0030] Furthermore, the coolant filling strategy for a hybrid vehicle as described in claim 6 is characterized in that: in step 3, the engine control unit (ECU) drives the P_Ewp water pump to work and starts timing, specifically as follows: STEP 1: The P_Ewp water pump starts and the duty cycle is 40%, and is maintained for 120s; STEP 2: The duty cycle of the P_Ewp water pump is set to 75%, and is maintained for 180s.

[0031] Furthermore, the hybrid vehicle coolant filling strategy as described in claim 6 is characterized in that: in step 4, the CLM drives the battery cooling system water pump B_Ewp to work and starts timing, specifically as follows: STEP1: The B_Ewp water pump starts and the duty cycle is 40%, and is maintained for 120s; STEP2: The duty cycle of the B_Ewp water pump is set to 75%, and is maintained for 180s.

[0032] The advantages of using the technical solution of this invention are:

[0033] This invention triggers the water valve and water pump switches of the vehicle's cooling system via a combination of buttons, ensuring that during manual coolant addition: 1. the cooling system circuit remains unobstructed, without obstruction from components such as water valves; 2. the coolant is circulated within the system by an electronic water pump, expelling air from the system and ensuring that the amount of coolant added during manual coolant addition meets the target requirements. Attached Figure Description

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0035] Figure 1 This is a schematic diagram of the thermal management system topology of the present invention;

[0036] Figure 2 This is a schematic diagram of the digital model layout structure of the thermal management system of the present invention;

[0037] Figure 3 This is a schematic diagram of the controller driver architecture of the present invention;

[0038] Figure 4 This is a schematic diagram of the coolant filling process of the present invention;

[0039] Figure 5 This is a graph showing the linear relationship between duty cycle and rotational speed in this invention.

[0040] The markings in the above diagram are as follows: 1. High-temperature radiator; 2. Proportional three-way valve I; 3. Proportional three-way valve II; 4. Heater; 5. Heat exchanger; 6. High-pressure heater; 7. Electric water pump I; 8. Expansion tank I; 9. Expansion tank II; 10. Water-cooled intercooler; 11. Electric water pump II; 12. Vehicle electric drive system controller; 13. Inverter; 14. Low-temperature radiator; 15. Battery; 16. Battery cooler; 17. Electric water pump III. Detailed Implementation

[0041] In this invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "planar direction," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the invention.

[0042] like Figures 1 to 4 As shown, a thermal management system for a hybrid vehicle includes a high-temperature cooling system, a low-temperature cooling system, and a battery cooling system connected by pipelines. The high-temperature cooling system includes an engine, a high-temperature radiator 1, a proportional three-way valve I 2, a proportional three-way valve II 3, a heater 4, a heat exchanger 5, a high-pressure heater 6, an electric water pump I 7, and an expansion tank I 8. The low-temperature cooling system and the battery cooling system share an expansion tank II 9. Expansion tanks I 8 and II 9 are located at the vehicle's coolant filler neck, serving to store and store coolant, and also to balance the operating pressure of the cooling system during operation. This thermal management system ensures that the cooling system circuit remains unobstructed during manual coolant filling, without obstructions from components such as water valves, guaranteeing that the amount of coolant added during manual filling meets the target requirements. This solves the problem in existing technologies where the actual amount of coolant added during manual filling of hybrid vehicles is less than the target amount.

[0043] The low-temperature cooling system includes a water-cooled intercooler 10, an electric water pump II 11, a vehicle electric drive system controller 12, an inverter 13, and an LTR low-temperature radiator 14. The water-cooled intercooler 10, the electric water pump II 11, the vehicle electric drive system controller 12, the inverter 13, and the low-temperature radiator 14 are connected by pipes.

[0044] The battery cooling system includes a battery 15, a battery cooler 16, a heat exchanger 5, and an electronic water pump III 17, which are connected by pipelines.

[0045] Electronic water pump I7 is an H_Ewp water pump, which drives both heating and battery heating functions; electronic water pump II11 is a P_Ewp water pump, used to drive the circulation of the WCAC, MCU and CCU cooling systems; electronic water pump III17 is a B_Ewp water pump, which is the battery cooling system pump. The proportional three-way valve I2 is 3wv1, the proportional three-way valve II3 is 3wv2, the high-temperature radiator 1 is HTR, the heater 4 is Heater, the heat exchanger 5 is CoolantPlate, the high-pressure heater 6 is HVH, the expansion tank I8 is Tank1; the water-cooled intercooler 10 is WCAC, the vehicle electric drive system controller 12 is MCU, the inverter 13 is CCU and the low-temperature radiator 14 is LTR, the expansion tank II9 is ​​Tank2; the battery 15 is Battery, the battery cooler 16 is Chiller, the heat exchanger 5 is CoolantPlate, and the electronic water pump III17 is B_Ewp.

[0046] The hybrid thermal management system topology can be divided into three system cycles: a high-temperature cooling system consisting of the engine, HTR, 3wv1, 3wv2, Heater, CoolantPlate, HVH, H_Ewp, and Tank1; a low-temperature cooling system consisting of WCAC, P_Ewp, MCU, CCU, and LTR; and a battery cooling system consisting of Battery, Chiller, CoolantPlate, and B_Ewp. The low-temperature cooling system and the battery cooling system share Tank2 and are filled using expansion tank II9.

[0047] Expansion tanks I8 and II9 are located at the highest point of the vehicle's coolant system in the Z direction. During the filling process, the caps of expansion tanks I8 and II9 are opened, and coolant is added. The liquid will flow to the bottom due to gravity.

[0048] The entire cooling system assembly is mainly divided into two circuits. The vehicle's power battery pack is connected to the battery cooler and electric water pump via coolant piping. The filling and pressure maintenance of the battery cooling system are handled by a separate expansion tank. Additionally, the vehicle's engine assembly (including the engine block, engine water-cooled intercooler, and turbocharger), motor controller, high-voltage inverter, drive motor, and other components requiring cooling, as well as the heating elements for the passenger compartment such as the air conditioning unit's heater core, are all connected via cooling piping to high-temperature radiators, low-temperature radiators, electric water pumps, and other cooling and heat dissipation components and drive components.

[0049] Figure 1The components and connecting pipes within the gray box on the left belong to the engine block: Water Jacket: This is the engine's water jacket, mainly composed of the cylinder block and cylinder head, and is a crucial component for heat exchange within the engine; EGR: Exhaust Gas Recirculation, which returns some of the exhaust gas to the intake manifold and re-enters the cylinders with the fresh air-fuel mixture, requiring coolant cooling; Oil_HX: Engine oil cooler, used for heat exchange between oil and coolant; TC: Short for Turbocharger, the engine's turbocharger, whose heat load needs to be dissipated through coolant; WCAC: Water-cooled intercooler, used to cool the turbocharged intake air, its heat requiring coolant transfer; Thermostat: Engine thermostat, which uses temperature sensing to control different coolant flow directions and circulation patterns; E_Ewp: Engine main electric water pump, the power component driving the coolant flow in this coolant system.

[0050] Figure 1 The gray box on the right represents the HVAC assembly: an abbreviation for Heating Ventilation and Air Conditioning. In this patent, the Heater component (a heat exchanger for coolant and air) inside the HVAC system participates in the circulation of the cooling system to achieve the heating function of the vehicle's passenger compartment.

[0051] The battery is the vehicle's power battery, and its thermal management regulation method is liquid cooling and liquid heating. The internal temperature of the battery pack is regulated by the coolant of different temperatures and flow rates in the surrounding environment. The chiller is a plated heat exchanger that allows air conditioning refrigerant and coolant to exchange heat. Its main function is to use air conditioning refrigerant to absorb heat from the coolant, thereby reducing the coolant temperature.

[0052] HVH stands for High Voltage Heater, an electrical device used for electrically heating coolant. CoolantPlate is a plated heat exchanger that facilitates heat exchange between coolants. In this invention, its function is to transfer heat from the high-temperature coolant to the battery cooling system circulation, thereby achieving battery heating.

[0053] H_Ewp: This is an electronic water pump that drives both heating and battery heating functions. It is mainly used to drive the circulation of coolant when the vehicle is in EV driving mode and the engine main water pump E_Ewp is not working.

[0054] 3WV1 and 3WV2: Both of these components are proportional three-way valves, which can achieve... Figure 1The flow direction switching of various modes, including 1→2, 1→3 (3wv2) and 1→2&3 (3wv2), is marked in the middle. This is used to match different electronic pump driven cooling systems to realize related functions such as battery heating and crew cabin heating.

[0055] MCU: Short for Motor Control Unit, it is the controller for the vehicle's electric drive system. This component requires coolant for cooling during operation. CCU: A combined inverter control unit and on-board charger, it mainly converts the operating voltage of the vehicle's electrical appliances and enables the vehicle's charging function. The heat generated during its operation needs to be absorbed by coolant.

[0056] LTR: Low-temperature radiator, a component for heat exchange between coolant and air. In this patent, its function is to exchange the heat generated by WCAC, MCU, and CCU with the outside air. P_Ewp: Electronic water pump that drives the circulation of the WCAC, MCU, and CCU cooling system; HTR: High-temperature radiator: mainly responsible for cooling the engine block and engine turbocharger. When the thermostat is open, the coolant coming out of the engine passes through the high-temperature radiator to cool the coolant.

[0057] Tank1 and Tank2 are expansion tanks in the vehicle's cooling system. Their function is to fill and store coolant, and also to balance the operating pressure of the cooling system during operation. Airleak cap: refers to a vent cap fixed to the pipeline, which can be manually unscrewed and tightened.

[0058] Tank1 and Tank2 are located at the highest point of the vehicle's coolant system in the Z direction. During the filling process, the expansion tank cap is opened and coolant is added. The liquid will flow to the bottom due to gravity. Due to the presence of air in the system and the existence of bends in the pipe connections of some components, gas may be present inside the cavities of some components, requiring auxiliary means to handle.

[0059] Based on the aforementioned thermal management system for hybrid vehicles, this invention also relates to a coolant filling strategy for hybrid vehicles, the coolant filling strategy execution steps including:

[0060] Step 1. Open the covers of expansion tank I8 and expansion tank II9, and simultaneously unscrew the air leak cap on the pipeline. Static add coolant, ensuring that the coolant level is between the Max and Min lines. Let it stand still and observe that the level does not drop within 10 minutes. At the same time, when you observe that coolant overflows from the air leak cap, screw the air leak cap back on.

[0061] Step 2. Wake up the vehicle and put it in the high-pressure Ready state. With the vehicle in P gear, use the vehicle's infotainment system air conditioning interface (AIPM) to simultaneously press and hold the Auto button and the rear defrost button for 5 seconds to wake up the air conditioning controller CLM and the engine control unit ECU.

[0062] Step 3. The engine control unit (ECU) drives the P_Ewp water pump to work and starts timing. The specific operation is as follows:

[0063]

[0064] Step 4. The CLM drives the battery cooling system water pump B_Ewp to start and begins timing. The specific operation is as follows:

[0065]

[0066] Step 5. For the control strategy of the high-temperature cooling system, the ECU and CLM need to work together for control. The specific operation is as follows:

[0067]

[0068]

[0069] The linear relationship between duty cycle and rotational speed is as follows: Figure 5 As shown, the conversion between the speed and duty cycle of E_Ewp and H_Ewp is realized. The linear relationship between duty cycle and speed is calculated. Since the control precision of the software is not so high in actual applications, the speed value can generally be rounded to the tens place. For example, in the calculation process, the speed corresponding to 60% duty cycle is 3681.8 rpm. In actual use, 3680 rpm can be used.

[0070] Combining the above table with Figure 5 It can be seen that the ECU and CLM control systems work together to control the four actuators—proportional three-way valve II, proportional three-way valve I, E_Ewp, H_Ewp, and Thermostat—in the following sequence, and manage timing: STEP 1: Set the flow direction of proportional three-way valve II to 1→2, the angle opening to 90°, and the water valve motor drive duty cycle to 33.33%; set the flow direction of proportional three-way valve I to 1→3, the angle opening to 240°, and the water valve motor drive duty cycle to 88.88%; set the speed of E_Ewp to 1500rpm, set H_Ewp to the Off state, set Thermostat to the On state, and start timing for 120 seconds.

[0071] STEP 2: Set the flow direction of proportional three-way valve II to 1→2, the opening angle to 90°, and the water valve motor drive duty cycle to 33.33%; set the flow direction of proportional three-way valve I to 1→2, the opening angle to 90°, and the water valve motor drive duty cycle to 33.33%; set the speed of E_Ewp to 1500rpm, set H_Ewp to Off, put the Thermostat on, and start timing for 120 seconds;

[0072] STEP 3: Set the flow direction of proportional three-way valve II to 1→2, the opening angle to 90°, and the water valve motor drive duty cycle to 33.33%; set the flow direction of proportional three-way valve I to 1→2&3, the opening angle to 180°, and the water valve motor drive duty cycle to 66.66%; set the speed of E_Ewp to 3000rpm, set H_Ewp to Off, put the Thermostat on, and start timing for 180 seconds;

[0073] STEP 4: Set the flow direction of proportional three-way valve II to 1→2&3, the angle opening to 180°, and the water valve motor drive duty cycle to 66.66%; set the flow direction of proportional three-way valve I to 1→2&3, the angle opening to 180°, and the water valve motor drive duty cycle to 66.66%; set the speed of E_Ewp to 3000rpm, set H_Ewp to Off, set the Thermostat to On, and start timing for 120 seconds;

[0074] STEP 5: Set the flow direction of proportional three-way valve II to 3→2, the angle opening to 0°, and the water valve motor drive duty cycle to 0%; set the flow direction of proportional three-way valve I to 1→2&3, the angle opening to 180°, and the water valve motor drive duty cycle to 66.66%; set E_Ewp to Off state, H_Ewp duty cycle to 50%, Thermostat to On state, and time for 60 seconds; through the linear relationship between duty cycle and speed, it can be seen that a 50% duty cycle of H_Ewp corresponds to a speed of 2950 rpm for H_Ewp;

[0075] STEP 6: Set the flow direction of proportional three-way valve II to 3→2, the angle opening to 0°, and the water valve motor drive duty cycle to 0%; set the flow direction of proportional three-way valve I to 1→3, the angle opening to 240°, and the water valve motor drive duty cycle to 88.88%; set the speed of E_Ewp to 4000rpm, set the duty cycle of H_Ewp to 75%, and put the Thermostat in the open state and start timing for 60 seconds; through the linear relationship between duty cycle and speed, it can be seen that a 75% duty cycle of H_Ewp corresponds to a speed of 4770rpm for H_Ewp;

[0076] STEP 7: Set the flow direction of proportional three-way valve II to 3→2, the angle opening to 0°, and the water valve motor drive duty cycle to 0%; set the flow direction of proportional three-way valve I to 1→2, the angle opening to 90°, and the water valve motor drive duty cycle to 33.33%; set the speed of E_Ewp to 4000rpm, set the duty cycle of H_Ewp to 75%, the Thermostat to be on, and start timing for 60 seconds; through the linear relationship between duty cycle and speed, it can be seen that a 75% duty cycle of H_Ewp corresponds to a speed of 4770rpm for H_Ewp;

[0077] STEP 8: Set the flow direction of proportional three-way valve II to 1→2&3, the angle opening to 180°, and the water valve motor drive duty cycle to 66.6%; set the flow direction of proportional three-way valve I to 1→2&3, the angle opening to 180°, and the water valve motor drive duty cycle to 66.6%; set the speed of E_Ewp to 4000rpm, set H_Ewp to Off state, put the Thermostat in the on state, and start timing for 180 seconds;

[0078] STEP 9: Set the flow direction of proportional three-way valve II to 1→2&3, the angle opening to 180°, and the water valve motor drive duty cycle to 66.6%; set the flow direction of proportional three-way valve I to 1→2&3, the angle opening to 180°, and the water valve motor drive duty cycle to 66.6%; set both E_Ewp and H_Ewp to Off state, and the Thermostat to On state.

[0079] Step 6. After the timing in steps 2-5 is completed, the refueling function is finished.

[0080] Step 7. The above steps can be repeated to achieve the function of multiple filling and venting. The final filling effect is observed until the liquid level in expansion tank I8 and expansion tank II9 is ​​between the Max line and the Min line and no longer changes.

[0081] This invention triggers the water valve and water pump switches of the vehicle's cooling system via a combination of buttons, ensuring that during manual coolant addition: 1. the cooling system circuit remains unobstructed, without obstruction from components such as water valves; 2. the coolant is circulated within the system by an electronic water pump, expelling air from the system and ensuring that the amount of coolant added during manual coolant addition meets the target requirements.

[0082] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the technical solution of the present invention, or the direct application of the concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A coolant filling strategy for hybrid vehicles, characterized in that: The thermal management system of the hybrid vehicle includes a high-temperature cooling system, a low-temperature cooling system, and a battery cooling system connected by pipelines. The high-temperature cooling system includes an engine, a high-temperature radiator (1), a proportional three-way valve I (2), a proportional three-way valve II (3), a heater (4), a heat exchanger (5), a high-pressure heater (6), an electric water pump I (7), and an expansion tank I (8). The low-temperature cooling system and the battery cooling system share an expansion tank II (9). The expansion tank I (8) and the expansion tank II (9) are located at the vehicle's coolant filling port, serving to store and accumulate coolant, and also to balance the operating pressure of the cooling system during operation. The low-temperature cooling system includes a water-cooled intercooler (10), an electric... The battery cooling system includes a battery (15), a battery cooler (16), a heat exchanger (5), and an electronic water pump III (17). The electronic water pump II (11) is a P_Ewp water pump used to drive the cooling system circulation of the water-cooled intercooler (10), the vehicle electric drive system controller (12), and the inverter (13). The electronic water pump III (17) is a B_Ewp water pump, which is the water pump for the battery cooling system. The electronic water pump I (7) is an H_Ewp water pump, which is an electronic water pump that drives both heating and battery heating functions. The coolant filling strategy execution steps include: Step 1. Open the covers of expansion tank I (8) and expansion tank II (9), and at the same time unscrew the vent caps on the pipelines to statically add coolant; Step 2. Wake up the vehicle and put it in high-pressure preparation state. With the vehicle in P gear, use the vehicle's infotainment system air conditioning interface AIPM to simultaneously press and hold the Auto button and the rear defrost button for 5 seconds to wake up the air conditioning controller CLM and the engine control unit ECU. Step 3. The engine control unit (ECU) drives the P_Ewp water pump to operate; Step 4. The air conditioning controller CLM drives the B_Ewp water pump to work; Step 5. For the control strategy of the high-temperature cooling system, the ECU and the air conditioning controller CLM need to work together for control; Step 6. After the timing in steps 2-5 is completed, the refueling function is finished. Step 7. The above steps can be repeated to achieve the function of multiple filling and venting. The final filling effect is observed until the liquid level of expansion tank I (8) and expansion tank II (9) is between the Max line and the Min line and no longer changes.

2. The coolant filling strategy for hybrid vehicles as described in claim 1, characterized in that: The water-cooled intercooler (10), electronic water pump II (11), vehicle electric drive system controller (12), inverter (13), and low-temperature radiator (14) are connected by pipelines.

3. The coolant filling strategy for hybrid vehicles as described in claim 2, characterized in that: The battery (15), battery cooler (16), heat exchanger (5), and electronic water pump III (17) are connected by pipelines.

4. The coolant filling strategy for a hybrid vehicle as described in claim 3, characterized in that: The expansion tanks I (8) and II (9) are located at the highest point of the vehicle's coolant system in the Z direction. During the filling process, the covers of expansion tanks I (8) and II (9) are opened, and coolant is added. The liquid will flow to the bottom due to gravity.

5. The coolant filling strategy for hybrid vehicles as described in claim 1, characterized in that: In step 1, when statically adding coolant, ensure that the coolant level is between the Max and Min lines, remain still and observe that the level does not drop within 10 minutes; at the same time, when you observe that coolant overflows from the vent cap, screw on the vent cap.

6. The coolant filling strategy for a hybrid vehicle as described in claim 1, characterized in that: In step 5, the ECU and CLM control systems work together to control the four actuators—proportional three-way valve II and proportional three-way valve I, E_Ewp water pump, H_Ewp water pump, and engine thermostat—in the following sequence, with timing management: STEP 1: Set the flow direction of proportional three-way valve II to 1→2, the opening angle to 90°, and the water valve motor drive duty cycle to 33.33%; Set the flow direction of the proportional three-way valve I to 1→3, the opening angle to 240°, and the duty cycle of the water valve motor drive to 88.88%; set the speed of the E_Ewp water pump to 1500rpm, set the H_Ewp water pump to the off state, set the engine thermostat to the on state, and start timing for 120 seconds. STEP 2: Set the flow direction of the proportional three-way valve II to 1→2, the opening angle to 90°, and the duty cycle of the water valve motor drive to 33.33%; Set the flow direction of the proportional three-way valve I to 1→2, the opening angle to 90°, and the duty cycle of the water valve motor drive to 33.33%; set the speed of the E_Ewp water pump to 1500rpm, set the H_Ewp water pump to the off state, set the engine thermostat to the on state, and start the timer for 120 seconds; STEP 3: Set the flow direction of the proportional three-way valve II to 1→2, the opening angle to 90°, and the duty cycle of the water valve motor drive to 33.33%; Set the flow direction of the proportional three-way valve I to 1→2&3, the angle opening to 180°, and the duty cycle of the water valve motor drive to 66.66%; set the speed of the E_Ewp water pump to 3000rpm, set the H_Ewp water pump to the off state, set the engine thermostat to the open state, and start timing for 180 seconds; STEP 4: Set the flow direction of the proportional three-way valve II to 1→2&3, the angle opening to 180°, and the duty cycle of the water valve motor drive to 66.66%; Set the flow direction of the proportional three-way valve I to 1→2&3, the angle opening to 180°, and the duty cycle of the water valve motor drive to 66.66%; set the speed of the E_Ewp water pump to 3000rpm, set the H_Ewp water pump to the off state, set the engine thermostat to the open state, and start timing for 120 seconds; STEP 5: Set the flow direction of proportional three-way valve II to 3→2, the angle opening to 0°, and the water valve motor drive duty cycle to 0%; set the flow direction of proportional three-way valve I to 1→2&3, the angle opening to 180°, and the water valve motor drive duty cycle to 66.66%; set the E_Ewp water pump to the off state, the H_Ewp water pump duty cycle to 50%, the engine thermostat to the on state, and start timing for 60 seconds; STEP 6: Set the flow direction of the proportional three-way valve II to 3→2, the angle opening to 0°, and the duty cycle of the water valve motor drive to 0%; The proportional three-way valve I is set to flow direction 1→3, angle opening is 240°, and water valve motor drive duty cycle is 88.88%; the E_Ewp water pump speed is set to 4000rpm, the H_Ewp water pump duty cycle is set to 75%, the engine thermostat is in the open state, and a timer is set for 60 seconds; STEP 7: Set the flow direction of proportional three-way valve II to 3→2, the angle opening to 0°, and the water valve motor drive duty cycle to 0%; set the flow direction of proportional three-way valve I to 1→2, the angle opening to 90°, and the water valve motor drive duty cycle to 33.33%; set the speed of E_Ewp water pump to 4000rpm, set the duty cycle of H_Ewp water pump to 75%, and set the engine thermostat to open and time for 60 seconds; STEP 8: Set the flow direction of proportional three-way valve II to 1→2&3, the opening angle to 180°, and the water valve motor drive duty cycle to 66.6%; set the flow direction of proportional three-way valve I to 1→2&3, the opening angle to 180°, and the water valve motor drive duty cycle to 66.6%; set the speed of E_Ewp water pump to 4000rpm, set H_Ewp water pump to the off state, set the engine thermostat to the open state, and start timing for 180 seconds; STEP 9: Set the flow direction of proportional three-way valve II to 1→2&3, the angle opening to 180°, and the water valve motor drive duty cycle to 66.6%; set the flow direction of proportional three-way valve I to 1→2&3, the angle opening to 180°, and the water valve motor drive duty cycle to 66.6%; both E_Ewp and H_Ewp water pumps are set to the off state, and the engine thermostat is in the open state.

7. The coolant filling strategy for a hybrid vehicle as described in claim 1, characterized in that: In step 3, the engine control unit (ECU) drives the P_Ewp water pump to work and starts timing. The specific operation is as follows: STEP 1: The P_Ewp water pump starts and the duty cycle is 40%, and is maintained for 120s; STEP 2: The duty cycle of the P_Ewp water pump is set to 75%, and is maintained for 180s.

8. The coolant filling strategy for a hybrid vehicle as described in claim 1, characterized in that: In step 4, the air conditioning controller CLM drives the B_Ewp water pump to work and starts timing. The specific operation is as follows: STEP1: The B_Ewp water pump starts and the duty cycle is 40%, and is maintained for 120s; STEP2: The duty cycle of the B_Ewp water pump is set to 75%, and is maintained for 180s.

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