CN109795313B - A plug-in hybrid electric vehicle thermal management system - Google Patents

Abstract

The invention provides a plug-in hybrid vehicle thermal management system, which integrates the independent engine cooling system, motor cooling system, battery cooling system, battery controller cooling system, etc. in the plug-in hybrid vehicle by means of integrated heat exchangers. Relevant systems are integrated into a whole thermal management system, using an integrated heat exchanger as the core heat exchange structure, and using multiple cooling circulation paths to conduct monitoring of engine oil, engine coolant, battery cooling system, battery controller cooling system, and motor cooling system. Heat exchange to achieve the optimal working temperature of each system. The invention makes full use of the waste heat generated by the operation of the engine, the waste heat generated by the battery discharge operation, and the waste heat generated by the heat dissipation of the motor operation, so that the energy of each system in the whole vehicle can be reasonably recycled and utilized, thereby saving energy and improving the efficiency of the vehicle thermal management system. the goal of.

Description

A plug-in hybrid electric vehicle thermal management system

technical field

The patent of the invention belongs to the field of automobile parts, and particularly relates to a thermal management system used in a plug-in hybrid electric vehicle.

Background technique

With the depletion of global oil resources and strict national emission regulations, due to the deep awareness of environmental protection, the state has encouraged the development of new energy vehicles in order to control the traditional fuel consumption of the whole vehicle. Resources, clean and pollution-free, supported and promoted by the state, hybrid vehicles, pure electric vehicles, plug-in hybrid vehicles and other types of vehicles have been launched in the domestic market. At present, plug-in hybrid vehicles in the domestic market, as a kind of new energy vehicles, are becoming more and more popular due to their features such as seamless switching between pure electric and fuel operation, long mileage, little limitation due to insufficient charging piles, and low fuel consumption. more people accept it.

During the normal running of the plug-in hybrid electric vehicle, the engine and the electric motor operate individually or in linkage according to the requirements of the vehicle controller. The optimum temperature when the engine is running is the coolant temperature of 80-105°C and the oil temperature of 110-135°C. The optimal temperature of the motor during operation is 30-70℃, the optimal temperature of the battery during continuous discharge is 18-25℃, and the optimal temperature of the battery control system (DCDC) during operation is within 60℃. When the engine and electric motor are running, plug-in hybrid vehicles commonly have four cooling circuits: engine cooling circuit, battery cooling circuit, motor cooling circuit, and motor controller cooling circuit. Most of the time periods are harmful and require separate cooling systems for heat dissipation. Now this part of the heat is basically directly connected to the radiator through the cooling module and dissipated directly into the air, which cannot be used to change the battery and engine to change the use environment.

At present, the thermal management systems of existing hybrid vehicles are generally independent of each other, and few thermal management systems such as engine cooling system, motor cooling system, battery cooling system are integrated together, which causes the difference in the whole vehicle. The temperature of the cooling system is an independent thermal management system. Due to the influence of the environment, the operating temperature cannot reach the optimal operating temperature, the heating time is too long, the long-term working efficiency is low, the energy consumption is high, and the maximum energy efficiency of the plug-in hybrid is not reached. The advantage is that the thermal energy resources in the different cooling systems of the whole vehicle are not fully utilized in the low temperature environment.

Due to the characteristics of the battery of electric vehicles, in the cold northern regions, the low temperature limits the charging and discharging of the battery, and the low temperature causes the battery to be unable to be charged or discharged too quickly. As a result, the electric mileage cannot meet the use of the vehicle in a complex environment, which makes it popular. subject to certain restrictions.

Under the pure electric working condition of the existing hybrid vehicle, when the engine stops for a long time, due to the low temperature of the engine coolant, the low temperature of the lubrication system, the high viscosity of the engine oil, and the increased friction during the initial operation of the engine; The body temperature is low, which is not conducive to the volatilization of fuel, the thermal efficiency of the engine is low, the combustion is insufficient, and the fuel consumption is also high. Therefore, the fuel consumption is much higher than during normal operation. Therefore, in the plug-in hybrid, although the engine does not participate in the operation for a long time, the fuel consumption reduction does not achieve the optimal effect in the cold start operation of the cooling system and the lubricating system for many times during the whole vehicle trip. . The heat of other heat-generating components is not fully utilized to preheat the engine, and the maximum utilization rate of thermal management resources is not achieved. When the engine is restarted, the viscosity of the lubricating oil is low, the frictional resistance is too large, and the fuel injection volume increases, which affects the economy of the whole vehicle. performance and emission performance. Specifically, the plug-in hybrid thermal management system needs to meet the real-time heating and cooling requirements of the whole vehicle and its main components under various operating conditions such as hybrid mode, pure electric mode, battery retention mode, and parking charging mode. , How to comprehensively utilize the heat in the working process of the engine, the electric motor and the battery to realize the thermal management system at the system level of the whole vehicle is one of the key technologies that needs to be overcome in the current plug-in hybrid electric vehicle.

Therefore, it is necessary to propose an improved technical solution to optimize the technical problems existing in the thermal management of the existing plug-in hybrid power, and comprehensively utilize the heat of the whole vehicle system.

SUMMARY OF THE INVENTION

The purpose of the present invention is to propose a vehicle thermal management system of a plug-in hybrid electric vehicle, which integrates the independent engine cooling system, motor cooling system, battery cooling system, battery The controller cooling system and other related systems are integrated into a whole thermal management system. The integrated heat exchanger is used as the core heat exchange structure, and multiple cooling circulation paths are adopted. , The motor cooling system conducts heat exchange to achieve the optimal working temperature of each system.

The present invention solves the technical problem by adopting the following technical solutions:

A vehicle thermal management system for a plug-in hybrid electric vehicle adopts an integrated heat exchanger, and the integrated heat exchanger has a plurality of cooling liquid running channels which are independent of each other and can perform heat exchange. The inlet and outlet, and each coolant running channel are respectively connected in series with the engine cooling system, motor cooling system, battery cooling system and other related systems through their respective three-way valves. The integrated heat exchanger can realize the transfer of heat between different cooling systems. A temperature sensor is arranged on the integrated heat exchanger, and the temperature is transmitted to the ECU or a separate controller through the temperature sensor and the temperature sensor in each cooling system. The comparison calculation is carried out on the above, and the flow direction control of each three-way valve is realized.

Further, the ECU or the separate controller compares the temperature signals collected by the temperature sensors of the engine cooling system, the motor cooling system, the battery cooling system, etc. with their required temperatures, and then compares them with the temperature collected by the temperature sensors of the integrated heat exchanger. In contrast, after calculation, the three-way control valve of each system is controlled to change the coolant circulation path, and then heat is exchanged through the integrated heat exchanger to maintain the temperature of the engine, motor and battery cooling system to reach the optimum operating temperature.

Further, in the engine cooling system, a sub-circuit is added to the basic cooling main circuit of an ordinary engine, and is connected in series with the integrated heat exchanger through the control of the first three-way control valve. The conventional engine cooling system consists of electronic water pump, thermostat, temperature sensor, oil cooler and radiator to form a main circuit. A first three-way controller is added to the conventional engine cooling main circuit, and the first three-way control valve forms an engine cooling sub-circuit through a pipeline and an integrated heat exchanger, and is finally connected to the main circuit. This sub-circuit can exchange heat with other cooling systems through an integrated heat exchanger. The flow direction of the first three-way control valve is controlled by the ECU or a separate controller. The first three-way control valve can switch the two circuits on and off, control the on-off and flow of different circuits, and indirectly form the temperature control in the circuit.

Further, the motor cooling system is to add a sub-circuit to the basic cooling main circuit of the common motor, which is controlled in series with the integrated heat exchanger through the second three-way control valve. The conventional motor cooling system is composed of a battery cooling unit, an electronic water pump, a temperature sensor, and a radiator to form a main circuit. A second three-way controller is added to the main circuit of conventional motor cooling, and the second three-way control valve is connected to the multi-layer integrated heat exchanger through pipelines to form a motor cooling sub-circuit, which is finally connected to the main circuit of the conventional motor cooling system. on the circuit. This sub-circuit can exchange heat with other cooling systems through an integrated heat exchanger. The flow direction of the second three-way control valve is controlled by the ECU or a separate controller. The second three-way control valve can switch the two circuits on and off, control the on-off and flow of different circuits, and indirectly form the temperature control in the circuit.

Further, the battery cooling system is to add a sub-circuit to the basic cooling main circuit of ordinary batteries, which is connected in series with the integrated heat exchanger through the control of the third three-way control valve. A conventional battery cooling system consists of a battery cooling unit, an electronic water pump, a temperature sensor, and a radiator to form a main circuit. A third three-way controller is added to the conventional battery cooling main circuit, and a battery cooling sub-circuit is formed by the three-way control valve connecting with the integrated heat exchanger through pipelines, and finally connected to the conventional battery cooling system. This sub-circuit can exchange heat with other cooling systems through an integrated heat exchanger. The flow direction of the third three-way control valve is controlled by the ECU or a separate controller. The third three-way control valve can switch the two circuits on and off, control the on-off and flow of different circuits, and indirectly form the temperature control in the circuit.

Further, the battery controller cooling system is to add a sub-circuit to the common battery controller cooling main circuit, which is controlled in series with the integrated heat exchanger through the fourth three-way control valve. The conventional battery controller cooling system consists of a battery controller cooling unit, an electronic water pump, a temperature sensor, and a radiator to form a main loop. A fourth three-way controller is added to the main cooling circuit of the conventional battery controller, and a cooling sub-circuit is formed by the fourth three-way control valve and the connected integrated heat exchanger through the pipeline, and finally connected to the cooling system of the conventional battery controller . This sub-circuit can exchange heat with other cooling systems through an integrated heat exchanger. The flow direction of the fourth three-way control valve is controlled by the ECU or a separate controller. The fourth three-way control valve can switch the two circuits on and off, control the on-off and flow of different circuits, and indirectly form the temperature control in the circuit.

The battery controller cooling system can be connected in series with the battery cooling system to form a cooling system, sharing the electronic water pump and the three-way control valve.

In the thermal management system of the present invention, when the motor runs alone, a large amount of waste heat is generated during the operation of the motor, the battery and the battery controller. In the motor cooling system, the heat is transferred to the cooling system through the motor cooling unit. By comparing the temperature sensor signals in the cooling system, the temperature in the motor cooling system is much higher than that in the engine cooling system. The ECU controls the second three-way control in the motor cooling system respectively. Valve and the first three-way control valve in the engine cooling system, make the coolant flow into the multi-layer integrated heat exchanger, transfer the temperature of the motor cooling system to the engine cooling system through heat conduction, increase the temperature of the engine cooling system, and at the same time the engine cooling system The oil is heated by the oil cooler, so that the engine water temperature and oil temperature are heated to about 60 ℃, which ensures that the engine can quickly enter the optimal working temperature when it is started. When the temperature of the engine cooling system is the same as that of the motor cooling system, the ECU controls the second three-way control valve in the motor cooling system and the first three-way control valve in the engine cooling system respectively, so that the motor coolant stops flowing to the multi-layer integrated heat exchanger , instead, it flows to the radiator, and the temperature balance of the cooling system is ensured through the heat dissipation of the radiator.

Both the battery cooling system and the battery controller cooling system can transfer waste heat to the engine cooling system through the integrated heat exchanger in the same way.

The thermal management system of the present invention starts the engine preferentially when the engine is running alone or in a low temperature environment in the north, and a large amount of waste heat is generated during the running of the engine. Among them, the engine cooling system transfers part of the heat generated by combustion to the cooling system through the cylinder block and cylinder head. By comparing the temperature sensor signals in the cooling system, when the engine cooling system is much higher than that of the motor, battery, motor controller and other cooling systems When the temperature is high, the ECU controls the first three-way control valve in the engine cooling system and the second three-way control valve in the motor cooling system respectively, so that the high-temperature coolant is divided into the integrated heat exchanger, and the heat of the engine cooling system is transferred to the integrated heat exchanger through heat conduction. In the motor cooling system, the temperature of the battery cooling system is increased, and the motor cooling system is heated by circulating in the motor cooling system. The switch of the second three-way control valve ensures that the motor is always at the best working temperature. The battery cooling system and the battery controller cooling system can be maintained at the optimal operating temperature in the same way.

In normal temperature use, heat is generated when the motor runs and the battery is discharged. Through the thermal management system of the present invention, the engine cooling and lubricating system is heated, so that the engine is always kept at the optimum operating temperature. When the engine needs to intervene in acceleration, the engine can quickly enter the economy. burning area. In the extreme low temperature environment, the whole vehicle controls the engine to start first, and through the thermal management system of the present invention, the battery cooling module is heated by the engine cooling and lubrication system, so that the battery pack is heated to the optimal use environment, and the battery charging capacity is improved (during the driving process) ) and extended discharge capacity. When the temperature of the electric part of the whole vehicle reaches the optimal operating environment, the electric system is started to run to reduce the fuel consumption during operation, and the heat generated by the operation of the motor is introduced into the battery cooling module to increase the temperature of the battery cooling system.

Through the thermal management system proposed by the present invention, each system can still operate independently or in combination, avoiding the mutual influence of each cooling system, and at the same time ensuring that each system operates at an optimal temperature, ensuring the function and performance of the system, and improving the performance of each component. life and efficiency.

The invention integrates the thermal management system of the motor and the battery and the engine cooling system, and makes full use of the waste heat generated by the operation of the engine, the waste heat generated by the discharge operation of the battery, and the waste heat generated by the operation of the motor to dissipate heat, so that the energy of each system in the whole vehicle is reasonable. Recycling and utilization, so that the engine, battery, and electric motor can reach the optimal operating environment, so as to save energy, improve the efficiency of the vehicle thermal management system, and maximize the utilization rate of the vehicle thermal environment resources; in the pure electric condition, make full use of the motor, The waste heat generated by the battery operation heats the engine cooling system to keep the engine water temperature at about 60°C. When the engine is required to run, it can quickly reach the optimal operating temperature; when in a low temperature environment, the engine operation mode utilizes the waste heat generated during engine operation. Heating the motor and battery system makes the motor and battery handle the best use environment, intervenes in the operation of the vehicle at any time, reduces the power consumption caused by low temperature, improves the energy saving, environmental protection and comfort of the vehicle, and effectively improves the economy and the vehicle. emission performance.

In the thermal management system of the present invention, when a single system has poor heat dissipation due to radiator failure, other cooling systems can be assisted in cooling through a multi-layer integrated heat exchanger, which can maximize the safety of the plug-in hybrid power system.

The thermal management system of the present invention can reduce the cooling requirements of a single system on the radiator, and reduce the volume and weight of the radiator. The problem of insufficient heat dissipation under extreme conditions can be solved by using three cooling systems to coordinate heat dissipation.

The invention has the advantages of simple structure, reliable performance, simple control and strong practicability.

Description of drawings

Fig.1 Schematic diagram of thermal management system of plug-in hybrid electric vehicle

Figure 2 Schematic diagram of engine cooling and lubrication system

Figure 3 Schematic diagram of engine cooling and lubrication system

Figure 4 Schematic diagram of battery cooling and lubrication system

Figure 5 Schematic diagram of battery cooling and lubrication system

Figure 6 Schematic diagram of the motor cooling and lubrication system

Figure 7 Schematic diagram of the motor cooling and lubrication system

Figure 8 Schematic diagram of heat exchange between battery and engine cooling and lubrication system

Figure 9 Schematic diagram of heat exchange between motor and engine cooling and lubrication system

Figure 10 Schematic diagram of heat exchange between motor and battery cooling system

Figure 11 Schematic diagram of heat exchange between motor, battery and engine cooling system

Figure 12 Schematic diagram of the structure of the integrated heat exchanger.

In the figure, 1-battery cooling module, 2-motor cooling module, 3-second radiator, 4-integrated heat exchanger, 5-engine cooling and lubrication module, 6-engine oil cooler, 7-first radiator, 8-Third radiator, 9-Third temperature sensor, 10-Third electronic water pump, 11-Second temperature sensor, 12-Second electronic water pump, 13-Second three-way control valve, 14-First temperature sensor , 15- the first electronic water pump, 16- the first three-way control valve, 17- thermostat, 18- the fourth temperature sensor, 19- the third three-way control valve, A1- is the coolant inlet, B1- is the cooling Liquid outlet, A2- is the coolant inlet, B2 is the coolant outlet, A3- is the coolant inlet, and B3- is the coolant outlet.

Detailed ways

The specific embodiments of the present invention are further described below with reference to the accompanying drawings. This embodiment takes the integration of the engine cooling system, the motor cooling system and the battery cooling system as an example. Other cooling systems such as the battery controller cooling system, The integration of motor controller cooling systems etc. is similar:

This embodiment provides a vehicle thermal management system for a plug-in hybrid electric vehicle, which uses an integrated heat exchanger to connect multiple independent systems in parallel with each other, and adjusts the temperature of each system by adjusting the flow of coolant through multiple three-way control valves . The specific implementation is as follows:

The structure of the plug-in hybrid electric vehicle thermal management system of this embodiment is shown in Figure 1, wherein the core component is the integrated heat exchanger 4, and the engine cooling system, the motor cooling system, and the battery cooling system are connected to the integrated heat exchanger through pipelines 4-phase connection, in the integrated heat exchanger 4, each cooling system is independent of each other, only heat energy exchange is performed, and cooling liquid mixing is not performed.

Figure 1 shows the three main systems of the engine cooling system, the motor cooling system, and the battery cooling system. The engine includes an oil cooling system, and the heat exchange between the engine coolant and the oil is realized through the oil cooler 6 . The cooling system such as the battery controller in the plug-in hybrid can also be connected to the integrated heat exchanger 4 or integrated in the motor cooling system.

In this embodiment, the engine cooling system is shown in FIG. 2 . The engine is composed of a cooling water jacket in the engine body 5 through a pipeline, a first electronic water pump 15 , a thermostat 17 , a first radiator 7 and a first temperature sensor 14 to form an engine. Basic structure of cooling system. On the basis of the engine cooling system, a first three-way control valve 16 is added to split a cooling passage. Specifically, a first three-way control valve 16, a first three-way control valve 16 and an integrated heat exchanger are added to the cooling water jacket outlet pipeline. 4 is connected and then connected to the first electronic water pump 15 to form an engine cooling sub-circuit. The first three-way control valve 16 can control the engine cooling system to connect the first radiator 7 and the integrated heat exchanger 4 to form a cooling circuit by switching on and off.

Operation mode 1 of the engine cooling system: As shown in FIG. 2 , when the first three-way control valve 16 forms a passage with the thermostat 17 and forms an open circuit with the integrated heat exchanger 4 . The operating mode of the engine cooling system is that the first electronic water pump 15 is pressurized, so that the coolant flows through the internal water jacket of the engine 5 to the oil cooler 6, the first three-way control valve 16, the thermostat 17, and the first radiator 7. Return to the water inlet of the first electronic water pump 15 to form a loop. When this circuit works, the heat of the engine is exchanged with the air through the first radiator 7 .

Operation mode 2 of the engine cooling system: As shown in FIG. 3 , when the first three-way control valve 16 forms a passage with the integrated heat exchanger 4 and forms an open circuit with the electronic thermostat 17 . The operation mode of the engine cooling system is that the first electronic water pump 15 is pressurized, so that the coolant flows through the internal water jacket of the engine 5 to the oil cooler 6, the first three-way control valve 16, the integrated heat exchanger 4, and then returns to the first electronic The water inlet of the water pump 15 forms a circuit. When this circuit works, the heat of the engine is exchanged with other systems through the integrated heat exchanger 4 .

In this embodiment, the battery cooling system is shown in FIG. 4 , which consists of a cooling water jacket in the battery body 1 through a pipeline, a third electronic water pump 10 , a third radiator 8 and a third temperature sensor 9 to form the basic structure of the battery cooling system . On the basis of the battery cooling system, a third three-way control valve 19 is added on the water outlet pipeline of the radiator to split a cooling passage, and is connected to the integrated heat exchanger 4 through the pipeline and then connected to the water inlet of the third electronic water pump 10. form a cooling circuit. The third three-way control valve 19 can be turned on and off to control the cooling liquid of the battery body, and can be connected to the first radiator 7 and the integrated heat exchanger 4 to form a cooling circuit.

Operation mode 1 of the battery cooling system: As shown in FIG. 4 , when the third three-way control valve 19 forms a passage with the third radiator 8 and forms an open circuit with the integrated heat exchanger 4 . The operation mode of the battery cooling system is that the third electronic water pump 10 is pressurized, so that the coolant flows through the third radiator 8 and the inner water jacket of the battery 1 and then returns to the water inlet of the third electronic water pump 10 to form a loop. When this circuit works, the heat of the battery is exchanged with the air through the third radiator 8 .

Operation mode 2 of the battery cooling system: As shown in FIG. 5 , when the third three-way control valve 19 forms a passage with the integrated heat exchanger 4 and forms an open circuit with the third radiator 8 . The operation mode of the battery cooling system is that the third electronic water pump 10 is pressurized so that the cooling liquid flows through the integrated heat exchanger 4 and the water jacket inside the battery 1 and then returns to the water inlet of the third electronic water pump 10 to form a loop. When this circuit works, the heat of the battery is exchanged with other systems through the integrated heat exchanger 4 .

In this embodiment, the motor cooling system is shown in FIG. 6 , which consists of the cooling water jacket in the motor body 2 through the pipeline, the second electronic water pump 12 , the second radiator 3 and the second temperature sensor 11 to form the basic structure of the motor cooling system . On the basis of the motor cooling system, a second three-way control valve 13 is added to the water inlet pipe of the second radiator to split a cooling passage, which is connected to the integrated heat exchanger 4 through the pipe and then connected to the water inlet of the second electronic water pump 12 connected to form a cooling circuit. The second three-way control valve 13 can be turned on and off to control the cooling liquid of the motor body, and can be connected to the second radiator 3 and the integrated heat exchanger 4 to form a cooling circuit.

Operation mode 1 of the motor cooling system: As shown in FIG. 6 , when the second three-way control valve 13 forms a passage with the second radiator 3 and forms an open circuit with the integrated heat exchanger 4 . The operation mode of the motor cooling system is that the second electronic water pump 12 is pressurized, so that the coolant flows through the second radiator 3 and the inner water jacket of the motor 2 and then returns to the water inlet of the second electronic water pump 12 to form a loop. When this circuit works, the heat of the motor exchanges heat with the air through the third radiator 8 .

Operation mode 2 of the battery cooling system: As shown in FIG. 7 , when the second three-way control valve 13 forms a passage with the integrated heat exchanger 4 and forms an open circuit with the second radiator 3 . The operation mode of the battery cooling system is that the second electronic water pump 12 is pressurized, so that the cooling liquid flows through the integrated heat exchanger 4 and the inner water jacket of the motor 2 and then returns to the water inlet of the second electronic water pump 12 to form a loop. When this circuit works, the heat of the battery is exchanged with other systems through the integrated heat exchanger 4 .

In this embodiment, the ECU controls the heat exchange between the engine cooling system, the motor cooling system and the battery cooling system: the input source of the ECU control signal is the integrated heat exchanger 4 and the temperature sensors of the three cooling systems, namely the third temperature sensor 9. The second temperature sensor 11 , the first temperature sensor 14 , and the fourth temperature sensor 18 . The ECU compares the temperature signals collected by the third temperature sensors 9, 11, and 14 with the required temperature of the battery system, the motor system and the engine system, and then compares it with the temperature of the integrated heat exchanger 4 collected by the fourth temperature sensor 18. The third, second and first three-way control valves 19 , 13 and 16 are then controlled to change the cooling liquid circulation path, and then heat exchange is performed through the integrated heat exchanger 4 .

The ECU adjusts the temperature of each system by controlling the coolant flow direction of the third, second and first three-way control valves 19, 13 and 16 and the operation and closing of the third, second and first electronic water pumps 10, 12 and 15.

The ECU controls the coolant flow direction of the third, second and first three-way control valves 19, 13 and 16 to keep the temperature of the integrated heat exchanger 4 at the optimum working temperature of 50-60°C.

When the engine is running, the ECU adjusts the flow rate of the engine coolant flowing through the integrated heat exchanger 4 and the flow rate through the radiator by controlling the switch of the first three-way control valve 16 to maintain the temperature of the engine cooling system to the optimum operating temperature . In the same way, when the motor and battery are running, the ECU keeps the motor and battery running at the optimum operating temperature through the same control, respectively.

In this embodiment, there are the following heat exchange modes among the cooling systems:

Method 1: Heat exchange between the battery and the engine: As shown in FIG. 8 , the ECU controls the third three-way control valve 19 and the first three-way control valve 16 to change the flow direction of the coolant in the cooling system. The ECU controls the first three-way control valve 16 so that the engine coolant flows to the integrated heat exchanger 4 through the first three-way control valve 16 and stops flowing to the first radiator 7; the ECU controls the third three-way control valve 19 to cool the battery The liquid flows to the integrated heat exchanger 4 through the third three-way control valve 19 and stops flowing to the third radiator 8 . When the engine is running, heat can be transferred from the engine cooling system to the battery cooling system through the integrated heat exchanger 4. When the engine is not started and the battery is running to release heat (motor running), the heat can be transferred from the battery to the battery through the integrated heat exchanger 4. The cooling system passes into the engine cooling system.

Method 2: Heat exchange between the motor and the engine: As shown in FIG. 9 , the ECU controls the second three-way control valve 13 and the first three-way control valve 16 to change the flow direction of the coolant in the cooling system. The ECU controls the first three-way control valve 16 so that the engine coolant flows to the integrated heat exchanger 4 through the first three-way control valve 16 and stops flowing to the first radiator 7; the ECU controls the second three-way control valve 13 to cool the motor The liquid flows to the integrated heat exchanger 4 through the second three-way control valve 13 and stops flowing to the second radiator 3 . When the engine is running, heat can be transferred from the engine cooling system to the motor cooling system through the integrated heat exchanger 4. When the engine is not started and the battery is running to release heat (the motor is running), the heat can be transferred from the battery through the integrated heat exchanger 4. The cooling system passes into the engine cooling system.

Mode 3 Heat exchange between the motor and the battery: As shown in FIG. 10 , the ECU controls the second three-way control valve 13 and the first three-way control valve 16 to change the flow direction of the coolant in the cooling system. The ECU controls the third three-way control valve 19 so that the battery coolant flows to the integrated heat exchanger 4 through the third three-way control valve 19 and stops flowing to the third radiator 8 . The ECU controls the second three-way control valve 13 so that the motor coolant flows to the integrated heat exchanger 4 through the second three-way control valve 13 and stops flowing to the second radiator 3 . When the motor is used, heat can be transferred from the motor cooling system to the battery cooling system via the integrated heat exchanger 4 .

Mode 4 Heat exchange between the motor and the battery: As shown in Figure 11, the ECU controls the second, first and third three-way control valves 13, 16 and 19 to change the flow direction of the coolant in the cooling system. The ECU controls the first three-way control valve 16 so that the engine coolant flows to the integrated heat exchanger 4 through the first three-way control valve 16 and stops flowing to the first radiator 7; the ECU controls the third three-way control valve 19 to cool the battery The liquid flows to the integrated heat exchanger 4 through the third three-way control valve 19 and stops flowing to the third radiator 8 . The ECU controls the second three-way control valve 13 so that the motor coolant flows to the integrated heat exchanger 4 through the second three-way control valve 13 and stops flowing to the second radiator 3 . When the engine is running, heat can be transferred from the engine cooling system to the motor and battery cooling system through the integrated heat exchanger 4. When the engine is not started and the battery is running to release heat (the motor is running), the heat can pass through the integrated heat exchanger 4. Passed to the engine cooling system by the motor and battery cooling system.

In a further embodiment, a structural form of an integrated heat exchanger is provided, as shown in FIG. 12, which integrates three layers of independent cooling liquid circulation paths, each layer of which has its own water inlet and outlet. The heat transfer can be carried out directly between the circuits in the integrated heat exchanger. The first cooling liquid enters through A1 port and flows out from B1 port; the second cooling liquid enters through A2 port and flows out from B2 port; the third cooling liquid enters through A3 port and flows out from B3 port; The cooling liquids in the middle and three channels conduct heat to each other through the metal walls between the channels, and the cooling liquids do not mix. This integrated heat exchanger can integrate an oil cooling circuit or more cooling circuits as required.

It can be seen from the above embodiments that the present invention uses an integrated heat exchanger to integrate the cooling systems in the plug-in hybrid vehicle for heat exchange, and makes full use of the waste heat generated by each system to keep the entire plug-in hybrid vehicle system at the optimum operating temperature. . Through the switch of the electronic water pump and the three-way control valve, the coolant flow to the integrated heat exchanger or radiator is changed, so that the temperature of each system is protected at its optimum working temperature, and it will not cause the temperature of some systems to exceed the range or the temperature exceeds the temperature. Low. By controlling the water pumps and three-way control valves of different cooling systems, one system, two systems or multiple systems can be mixed heat exchange. Each cooling system is independent of each other, and the coolants are not mixed with each other, and the failure of a single system does not affect the normal use of other cooling systems. When a single cooling system fails, other cooling systems can temporarily supplement the cooling system with integrated heat exchangers.

Claims (6)

1. A plug-in hybrid electric vehicle thermal management system comprises an engine cooling system, a motor cooling system and a battery cooling system which respectively form closed circulation, and is characterized by further comprising an integrated heat exchanger, wherein a plurality of mutually independent cooling liquid operation channels capable of carrying out heat exchange are arranged in the integrated heat exchanger, each cooling liquid operation channel is provided with an inlet and an outlet respectively, and the inlet and the outlet are respectively connected with the engine cooling system, the motor cooling system, the battery cooling system and the battery controller cooling system in series through a three-way valve, so that heat can be mutually transferred among different cooling systems; the integrated heat exchanger is provided with a temperature sensor, and the temperature sensor in each cooling system transmit the temperature to an ECU or an independent controller for comparison and calculation, so that the flow direction of each three-way valve is controlled;

the ECU or the independent controller compares temperature signals acquired by temperature sensors of an engine cooling system, a motor cooling system and a battery cooling system with the required temperatures of the engine cooling system, the motor cooling system and the battery cooling system, then compares the temperature signals with the temperature acquired by the temperature sensor of the integrated heat exchanger, controls the three-way control valve of each system to change a cooling liquid circulation path after calculation, and then performs heat exchange through the integrated heat exchanger to maintain the temperature of the engine, the motor and the battery cooling system to reach the running temperature;

the engine cooling system is characterized in that a sub-loop is added in an engine cooling main loop, namely a first three-way control valve is added on a water outlet pipeline of a cooling water jacket, one cooling channel is split and is controlled to be connected with an integrated heat exchanger in series through the first three-way control valve, the sub-loop forms heat exchange with other cooling systems through the integrated heat exchanger, the flow direction of the first three-way control valve is controlled through an ECU (electronic control Unit) or an independent controller, and the first three-way control valve controls the on-off and the flow of the two loops to indirectly form temperature control in the loops;

the motor cooling system is characterized in that a sub-loop is added in a motor cooling main loop, namely a second three-way control valve is added on a water inlet pipeline of a radiator in the loop, a cooling passage is split, the sub-loop is controlled to be connected with an integrated heat exchanger in series through the second three-way control valve, the sub-loop forms heat exchange with other cooling systems through the integrated heat exchanger, the flow direction of the second three-way control valve is controlled through an ECU (electronic control Unit) or an independent controller, the second three-way control valve controls the on-off and the flow of different loops, and the temperature control in the loops is indirectly formed;

the battery cooling system is characterized in that a sub-loop is added in a main battery cooling loop, namely a third three-way control valve is added on a water outlet pipeline of a radiator of the main battery cooling loop to split a cooling channel, the third three-way control valve is controlled to be connected with an integrated heat exchanger in series, the sub-loop forms heat exchange with other cooling systems through the integrated heat exchanger, the ECU or an independent controller controls the flow direction of the third three-way control valve, the third three-way control valve controls the on-off and the flow of different loops, and the temperature control in the loops is indirectly formed;

the battery controller cooling system is characterized in that a sub-loop is added in a main battery controller cooling loop and is controlled by a fourth three-way control valve to be connected with an integrated heat exchanger in series.

2. The plug-in hybrid electric vehicle thermal management system according to claim 1, wherein the engine cooling main loop is formed by connecting an engine body cooling water jacket with a first electronic water pump, a thermostat, a first radiator and a first temperature sensor through pipelines, a first three-way control valve is additionally arranged on a water outlet pipeline of the cooling water jacket, a cooling passage is split, and the cooling passage is connected with the integrated heat exchanger through a pipeline and then connected with the first electronic water pump to form an engine cooling sub-loop.

3. The plug-in hybrid electric vehicle thermal management system according to claim 1, wherein the motor cooling main loop is composed of a motor body cooling water jacket, a second electronic water pump, a second radiator and a second temperature sensor through pipelines, a second three-way control valve is additionally arranged on a water inlet pipeline of the second radiator, one cooling channel is split, and the cooling channel is connected with the integrated heat exchanger through a pipeline and then connected with a water inlet of the second electronic water pump to form a motor cooling sub-loop.

4. The plug-in hybrid electric vehicle thermal management system according to claim 1, wherein the battery cooling main loop is formed by connecting a battery body internal cooling water jacket with a third electronic water pump, a third radiator and a third temperature sensor through pipelines, a third three-way control valve is added on a water outlet pipeline of the radiator to split a cooling passage, and the cooling passage is connected with the integrated heat exchanger through a pipeline and then connected with a water inlet of the third electronic water pump to form a battery cooling sub-loop.

5. The plug-in hybrid vehicle thermal management system according to claim 1, 2, 3 or 4, wherein the added sub-loop of the battery controller cooling system exchanges heat with other cooling systems through an integrated heat exchanger, and the flow direction of a fourth three-way control valve is controlled by an ECU or a separate controller, and the fourth three-way control valve controls the on-off and flow of the two loops to indirectly control the temperature in the loops.

6. The plug-in hybrid vehicle thermal management system according to claim 5, wherein the integrated heat exchanger integrates an oil cooling circuit or more cooling circuits as needed.

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