A new energy electric vehicle thermal management system and thermal management method

Abstract

The present invention relates to a thermal management system and thermal management method for a new energy electric vehicle, including a refrigerant circulation loop, a coolant circulation loop and a battery heating loop, wherein the refrigerant circulation loop is composed of a compressor, a condenser, a throttling element and an evaporator connected in sequence, and the coolant circulation loop includes a first heat exchanger connected in sequence, a second heat exchanger installed inside a heating element and a heat dissipation device, the heat dissipation device can be selectively connected between the outlet end of the second heat exchanger and the inlet end of the first heat exchanger, the heat dissipation device includes an in-vehicle heating device and / or an out-vehicle heat dissipation device, the in-vehicle heating device and the out-vehicle heat dissipation device are connected in parallel, the heating element includes a battery, a motor and an electric control unit, and the coolant in the first heat exchanger performs heat exchange with the refrigerant in the evaporator. The present invention provides a comprehensive thermal management system that can simultaneously perform effective heat management for the battery, motor and electric control unit on the vehicle, so as to achieve the purpose of energy saving and high efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of thermal management, and in particular relates to a thermal management system and a thermal management method for a new energy electric vehicle. Background Art

[0002] Under the overall demand for energy conservation and emission reduction, new energy vehicles have become a general trend, and the "three major electric" motors, batteries and electronic control components on new energy vehicles need to be guaranteed to work normally at a reasonable operating temperature. At present, new energy vehicles generally only perform thermal management on batteries, using a refrigerant circulation loop composed of a compressor, condenser, throttling element and evaporator to cool the battery, and then using a heating loop to heat the battery at low temperatures to keep the battery within a normal operating temperature range, but the heat of the battery is not effectively recycled and reused, resulting in heat waste. At the same time, as long as the battery needs to be cooled, the compressor in the refrigerant circulation loop is started, consuming a lot of power, and new energy vehicles in the existing technology do not effectively manage the heat of motors and electronic control components. Summary of the invention

[0003] The main technical problem solved by the present invention is to provide a new energy electric vehicle thermal management system and thermal management method that can simultaneously perform unified heat management for multiple heating elements on the vehicle and effectively reduce energy consumption.

[0004] To achieve the above object, the technical solution of the present invention is:

[0005] A new energy electric vehicle thermal management system includes a refrigerant circulation loop, a coolant circulation loop and a battery heating loop, wherein the refrigerant circulation loop is composed of a compressor, a condenser, a throttling element and an evaporator connected in sequence, and the coolant circulation loop includes a first heat exchanger connected in sequence, a second heat exchanger installed inside a heating element and a heat dissipation device, the heat dissipation device can be selectively connected between the outlet end of the second heat exchanger and the inlet end of the first heat exchanger, the heat dissipation device includes an in-vehicle heating device and / or an out-vehicle heat dissipation device, the in-vehicle heating device and the out-vehicle heat dissipation device are connected in parallel, the heating element includes a battery, a motor and an electronic control unit, the second heat exchangers in each heating element are connected in parallel with each other, and the coolant in the first heat exchanger exchanges heat with the refrigerant in the evaporator.

[0006] Furthermore, a power pump is serially connected to the inlet end of each of the second heat exchangers or a power pump is serially connected to the total loop of the coolant circulation loop.

[0007] Furthermore, the evaporator and the first heat exchanger are plate heat exchangers.

[0008] Furthermore, the in-vehicle heating device includes a foot radiator and / or a face radiator and / or a window radiator.

[0009] Furthermore, a first control valve for selectively connecting the heat dissipation device is installed between the inlet and outlet ends of the heat dissipation device, a second control valve for selectively connecting the in-vehicle heating device is installed at the inlet end of the in-vehicle heating device, and a third control valve for selectively connecting the inlet end of the external radiator is installed at the inlet end of the external radiator.

[0010] Furthermore, a temperature detection device for detecting the temperature of the coolant at the inlet end is provided at the inlet end of the first heat exchanger, and the controller controls the actions of the first control valve, the second control valve and the third control valve according to the detection result of the temperature detection device, and selectively connects the in-vehicle heating device and / or the external cooling device.

[0011] Furthermore, the battery heating circuit is composed of a heating element, a power pump, a second heat exchanger installed in the battery and a fourth control valve connected in sequence. A fifth control valve is arranged at the inlet end of the battery heating circuit, and the fifth control valve is used to selectively cut off the battery heating circuit from the rest of the coolant circulation circuit.

[0012] Furthermore, the heating element is an electric heater.

[0013] Another technical solution of the present invention is:

[0014] A thermal management method for a new energy electric vehicle utilizes heat exchange between an evaporator in a refrigeration circulation loop and a first heat exchanger in a coolant circulation loop to cool the coolant, connects the corresponding coolant circulation loop according to the cooling temperature control setting conditions of the battery, motor and electronic components, cools the battery, motor and electronic components respectively, and recovers the heat of the battery, motor and electronic components. In winter, the recovered heat is introduced into the vehicle to assist in regulating the temperature inside the vehicle, and when the battery temperature is lower than the heating temperature control setting conditions, the battery heating loop is started to heat the battery.

[0015] Furthermore, the temperature of the coolant at the inlet end of the first heat exchanger is detected, and the controller compares the detected temperature with the cooling temperature control setting conditions of the battery, motor and electronic components. When the detected temperature is lower than the cooling temperature control setting conditions, the actions of the first control valve, the second control valve and the third control valve are controlled, and the in-vehicle heating device and / or the outdoor cooling device are turned on to cool the coolant by using the in-vehicle heating device and / or the outdoor cooling device. When the detected temperature is higher than the cooling temperature control setting conditions, the compressor in the refrigeration cycle is turned on to cool the coolant by using the refrigerant.

[0016] In summary, the thermal management system and thermal management method of a new energy electric vehicle provided by the present invention have the following advantages compared with the prior art:

[0017] (1) The present invention provides a comprehensive thermal management system that can effectively manage the heat of the "three major electrics" on the vehicle: batteries, motors, and electronic components. The heat generated by the batteries, motors, and electronic components can also be effectively recycled and reused to assist in controlling the temperature of the entire vehicle passenger room in winter, thereby achieving energy saving and high efficiency.

[0018] (2) The present invention can utilize the heat dissipation device to cool the coolant. When the heat dissipation device can meet the coolant cooling conditions, there is no need to start the compressor, which can greatly reduce energy consumption and further improve the energy-saving effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a diagram of the thermal management system of the present invention.

[0020] like Figure 1 As shown, battery 1, motor 2, electronic control unit 3, compressor 4, condenser 5, throttling element 6, evaporator 7, first heat exchanger 8, second heat exchanger 9, second heat exchanger 10, second heat exchanger 11, power pump 12, power pump 13, power pump 14, in-vehicle radiator 15, in-vehicle fan 16, outdoor radiator 17, outdoor fan 18, first control valve 19, second control valve 20, third control valve 21, fourth control valve 22, fifth control valve 23, electric heater 24, expansion tank 25. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0022] like Figure 1 As shown, the present invention provides a new energy electric vehicle thermal management system, which performs unified thermal management on the three major heat generating components on the vehicle, namely, battery 1, motor 2, and electric control unit 3. The thermal management system includes a refrigerant circulation loop, a coolant circulation loop, and a battery heating loop.

[0023] The refrigerant circulation circuit is composed of a compressor 4, a condenser 5, a throttling element 6 and an evaporator 7 which are sequentially connected through refrigerant pipelines.

[0024] The cooling liquid circulation loop comprises a first heat exchanger 8 connected in sequence through pipelines, a second heat exchanger installed inside the heating element and a heat dissipation device. An expansion tank 25 is installed in the cooling liquid circuit to replenish the required cooling liquid in the cooling liquid circulation loop.

[0025] In this embodiment, the coolant circulation loop includes three groups connected in parallel, which are used to cool down the battery 1, the motor 2, and the electronic control unit 3. A second heat exchanger is installed in each of the battery 1, the motor 2, and the electronic control unit 3. Among them, the second heat exchanger 9 is installed in the battery 1, the second heat exchanger 10 is installed in the motor 2, and the second heat exchanger 11 is installed in the electronic control unit 3. The second heat exchanger 9, the second heat exchanger 10, and the second heat exchanger 11 are connected in parallel between the inlet and outlet ends of the first heat exchanger 8. The evaporator 7 and the first heat exchanger 8 can use all types of heat exchangers for heat exchange between refrigerant and coolant. In this embodiment, a plate heat exchanger with a simple and compact structure and high heat exchange efficiency is preferably used. The coolant in the first heat exchanger 8 and the low-temperature refrigerant in the evaporator 7 are heat exchanged in the plate heat exchanger. After cooling, the coolant in the first heat exchanger 8 is divided into three paths and enters three second heat exchangers 9, 10, and 11 respectively to cool down the battery 1, the motor 2, and the electronic control unit 3.

[0026] A power pump 12 is connected in series at the inlet end of the second heat exchanger 9, a power pump 13 is connected in series at the inlet end of the second heat exchanger 10, and a power pump 14 is connected in series at the inlet end of the second heat exchanger 11. The power pump selects a water pump. According to the cooling requirements of the battery 1, the motor 2, and the electronic control unit 3, that is, to meet the corresponding cooling temperature control setting conditions, the power pump at the inlet end of the heating element that needs to be cooled is started accordingly, so that the low-temperature coolant flows into the corresponding second heat exchanger and takes away the heat. In order to simplify the system, it is also possible to connect a power pump (not shown in the figure) in series at the outlet of the first heat exchanger 8, that is, on the total loop of the coolant circulation loop, and the power is provided by a power pump. A control valve can be connected in series in front of each of the three second heat exchangers to control the cooling cycle of different heating elements.

[0027] The heat dissipation device is connected between the outlet ends of the three second heat exchangers 9, 10, and 11 and the inlet end of the first heat exchanger 8. The heat dissipation device includes an in-vehicle heating device and an out-vehicle heat dissipation device, and the in-vehicle heating device and the out-vehicle heat dissipation device are connected in parallel. Among them, the in-vehicle heating device includes an in-vehicle radiator 15 and an in-vehicle fan 16 installed on one side of the in-vehicle radiator 15. The in-vehicle radiator 15 includes but is not limited to a foot radiator, a face radiator, and a window radiator in the vehicle. The in-vehicle radiators are connected in parallel to facilitate the user to open the corresponding in-vehicle radiator as needed to adjust the temperature in the vehicle. The out-vehicle heat dissipation device includes an out-vehicle radiator 17 and an out-vehicle fan 18 installed on one side of the out-vehicle radiator 17. The out-vehicle radiator 17 is installed outside the vehicle, and the coolant exchanges heat with the air outside the vehicle through the out-vehicle radiator 17.

[0028] A first control valve 19 for selectively connecting the cooling device is installed on the collecting pipe of the coolant circuit between the inlet and outlet ends of the cooling device, a second control valve 20 for selectively connecting the in-vehicle radiator 15 is installed at the inlet end of the in-vehicle radiator 15, and a third control valve 21 for selectively connecting the inlet end of the out-vehicle radiator 17 is installed.

[0029] In winter, if it is necessary to use the recovered heat to heat up the interior of the vehicle, the first control valve 19 and the second control valve 20 are controlled to open, and the coolant with a higher temperature that has absorbed the heat of the heating element flows through the radiator 15 in the vehicle, exchanges heat with the air in the vehicle compartment, and heats up the environment in the vehicle compartment. While heating up the interior of the vehicle compartment, the coolant can also be cooled. When it is necessary to use the radiator 17 outside the vehicle to cool down the coolant, the first control valve 19 and the corresponding third control valve 21 are controlled to open, and the coolant with a higher temperature that has absorbed the heat of the heating element flows through the radiator 17 outside the vehicle, and exchanges heat with the air with a lower temperature outside the vehicle, and cools down the coolant. If the heat dissipation device does not need to be connected, the first control valve 19 is closed, and the coolant flows directly back to the first heat exchanger 8 after flowing out of the second heat exchanger of the heating element. By opening and closing the first control valve 19, the second control valve 20 and the third control valve 21, the flow direction of the coolant is reasonably controlled, and energy is reasonably distributed, achieving the purpose of energy saving and high efficiency.

[0030] In this embodiment, a temperature detection device (not shown in the figure) for detecting the temperature of the coolant at the inlet end is preferably provided at the inlet end of the first heat exchanger 8. The temperature detection device is connected to the controller, and the controller controls the start and stop of the compressor 4 according to the comparison between the detected temperature and the cooling temperature control setting conditions of the battery 1, the motor 2 and the electronic control component 3. For example, the cooling temperature control setting conditions of the battery 1 are 20°C, and the cooling temperature control setting conditions of the motor 2 and the electronic control component 3 are 40°C. That is, when the temperature of the battery 1 is greater than or equal to 20°C, and the temperature of the motor 2 and the electronic control component 3 is greater than or equal to 40°C, it is necessary to cool the battery 1, the motor 2 and the electronic control component 3. When the ambient temperature is low, such as in winter, the ambient temperature outside the vehicle is lower than the cooling temperature control setting condition, then the first control valve 19, the second control valve 20 and the third control valve 21 are controlled to connect the heating device inside the vehicle and / or the heat dissipation device outside the vehicle, and the cooling liquid is cooled by the heating device inside the vehicle and / or the heat dissipation device outside the vehicle. At this time, the temperature of the cooling liquid at the inlet end of the first heat exchanger 8 is detected in real time. When the cooling liquid temperature is lower than the cooling temperature control setting condition, only the heating device inside the vehicle and / or the heat dissipation device outside the vehicle are used to cool the cooling liquid, and the compressor 4 is not turned on. Only when the detected cooling liquid temperature is higher than the cooling temperature control setting condition, the compressor 4 in the refrigeration cycle is turned on to cool the cooling liquid by the refrigerant. In this way, under the premise of ensuring the normal operation of the three heating components, energy consumption can be greatly reduced to achieve the purpose of energy saving.

[0031] The low temperature characteristics of the power battery determine that when the temperature of the battery 1 is lower than a certain value, the battery 1 needs to be heated to ensure its normal operation. The battery heating circuit heats the battery 1 when the temperature of the battery 1 reaches the heating temperature control setting condition. The battery heating circuit is composed of a heating element, a power pump 12, a second heat exchanger 9 installed in the battery 1, and a fourth control valve 22 connected in sequence. The heating element, the power pump 12, the second heat exchanger 9 and the fourth control valve 22 are connected by pipelines to form an independently operable coolant circuit, wherein the heating element preferably uses an electric heater 24, and more preferably a PTC heater. A fifth control valve 23 is provided at the inlet end of the battery heating circuit, and the fifth control valve is used to selectively cut off the battery heating circuit from the rest of the coolant circulation circuit. When the temperature of the battery 1 is lower than the heating temperature control setting condition (such as 8°C), the fifth control valve 23 is closed, the fourth control valve 22 is connected, and the electric heater 24 is used to heat the coolant. The heated coolant enters the second heat exchanger 9 under the action of the power pump 12 to heat the battery 1. The coolant with a lower temperature flowing out of the second heat exchanger 9 passes through the fourth control valve 22 and then is heated by the electric heater 24 to form a heating cycle. The battery heating circuit uses a part of the battery 1 coolant circulation circuit, and uses the fifth control valve 23 to selectively cut off and connect the battery heating circuit with the rest of the coolant circulation circuit, making the entire system simpler.

[0032] The thermal management method is described in detail below, including the following:

[0033] Heating process:

[0034] When the temperature of the battery 1 is lower than the heating temperature control setting condition (such as 8°C), the electric heater 24 is powered on for heating, and the fifth control valve 23 is closed at the same time, the battery heating circuit is disconnected from the rest of the coolant circulation circuit, and the fourth control valve 22 is connected to form an independent heating cycle. The heated coolant enters the second heat exchanger 9 inside the battery 1 under the action of the power pump 12 to heat the battery 1. The coolant with a lower temperature flowing out of the second heat exchanger 9 passes through the fourth control valve 22 and then is heated by the electric heater 24, forming an independent heating cycle.

[0035] Refrigeration process:

[0036] When the temperature of the battery 1, the motor 2 and the electronic control unit 3 is greater than or equal to the cooling temperature control setting condition, the corresponding power pump is started, and the compressor 4 is turned on at the same time to perform a refrigeration cycle, and the low-temperature refrigerant in the evaporator 7 is used to cool the coolant in the first heat exchanger 8. The low-temperature coolant then flows through the battery 1, the motor 2 and the second heat exchanger in the electronic control unit 3 in turn to cool the battery 1, the motor 2 and the electronic control unit 3. At the same time, the heat of the battery 1, the motor 2 and the electronic control unit 3 is taken away, and the coolant with a higher temperature flows back to the first heat exchanger 8 to exchange heat with the refrigerant in the evaporator 7 to form a coolant circulation.

[0037] Energy Recovery:

[0038] When the temperature outside the vehicle is low, such as in winter, the first control valve 19 and the second control valve 20 are controlled to open, and the coolant with a higher temperature after passing through the battery 1, the motor 2 and the second heat exchanger in the electronic control unit 3 flows through the radiator 15 in the vehicle, exchanges heat with the air in the vehicle, and uses the coolant with a higher temperature to heat the air in the vehicle compartment to assist in regulating the temperature of the vehicle compartment. The coolant with a lower temperature after heat exchange flows back to the first heat exchanger 8, exchanges heat with the low-temperature refrigerant to cool down, and continues the circulation of the coolant.

[0039] When the temperature outside the vehicle is low, that is, the temperature is lower than the cooling temperature control setting conditions of the battery 1, the motor 2 and the electronic control unit 3, the first control valve 19 and the third control valve 21 can be controlled to open, and the coolant with a higher temperature after passing through the second heat exchanger in the battery 1, the motor 2 and the electronic control unit 3 flows through the external radiator 17, exchanges heat with the low-temperature air outside the vehicle, and uses the external radiator 17 to cool the coolant. At this time, the temperature of the coolant at the inlet end of the first heat exchanger 8 is detected in real time. When the coolant temperature is lower than the cooling temperature control setting conditions, only the external heat dissipation device is used to cool the coolant, and the compressor 4 is not turned on. Only when the detected coolant temperature is higher than the cooling temperature control setting conditions, the compressor 4 in the refrigeration cycle is turned on to use the refrigerant to cool the coolant.

[0040] As described above, similar technical solutions can be derived from the scheme contents given in the accompanying drawings. However, any simple modification, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention without departing from the contents of the technical scheme of the present invention still fall within the scope of the technical scheme of the present invention.

Claims

1. A thermal management system for a new energy electric vehicle, characterized in that: It includes a refrigerant circulation loop, a coolant circulation loop and a battery heating loop, wherein the refrigerant circulation loop is composed of a compressor, a condenser, a throttling element and an evaporator connected in sequence, the coolant circulation loop includes a first heat exchanger connected in sequence, a second heat exchanger installed inside a heating element and a heat dissipation device, the coolant in the first heat exchanger performs heat exchange with the refrigerant in the evaporator, the heating element includes a battery, a motor and an electric control unit, a second heat exchanger is installed in each of the battery, the motor and the electric control unit, and three of the second heat exchangers are connected in parallel between the inlet end and the outlet end of the first heat exchanger; The heat dissipation device can be selectively connected between the outlet end of the second heat exchanger and the inlet end of the first heat exchanger, the heat dissipation device includes an in-vehicle heating device and an out-vehicle heat dissipation device, the in-vehicle heating device and the out-vehicle heat dissipation device are connected in parallel, a first control valve for selectively connecting the heat dissipation device is installed between the inlet end and the outlet end of the heat dissipation device, a second control valve for selectively connecting the in-vehicle heating device is installed at the inlet end of the in-vehicle heating device, and a third control valve for selectively connecting the out-vehicle radiator is installed at the inlet end of the out-vehicle radiator, and the controller controls the first control valve, the second control valve, and the third control valve to act according to the comparison between the detected temperature and the cooling temperature control setting conditions of the battery, the motor and the electric control unit, and selectively connects the in-vehicle heating device and / or the out-vehicle heat dissipation device, so as to cool the coolant by using the in-vehicle heating device and / or the out-vehicle heat dissipation device; The battery heating circuit is composed of a heating element, a power pump, a second heat exchanger installed in the battery and a fourth control valve connected in sequence. A fifth control valve is arranged at the inlet end of the battery heating circuit. The battery heating circuit utilizes a part of the battery coolant circulation circuit, and the fifth control valve is used to selectively cut off and connect the battery heating circuit with the rest of the coolant circulation circuit.

2. A thermal management system for a new energy electric vehicle according to claim 1, characterized in that: A power pump is serially connected to the inlet end of each of the second heat exchangers or a power pump is serially connected to the total loop of the coolant circulation loop.

3. A thermal management system for new energy electric vehicles according to claim 1, characterized in that: The evaporator and the first heat exchanger are plate type heat exchangers.

4. A thermal management system for a new energy electric vehicle according to claim 1, characterized in that: The in-vehicle heating device comprises a foot radiator and / or a face radiator and / or a window radiator.

5. A thermal management system for a new energy electric vehicle according to claim 1, characterized in that: A temperature detection device for detecting the temperature of the coolant at the inlet end is provided at the inlet end of the first heat exchanger, and a controller controls the actions of the first control valve, the second control valve and the third control valve according to the detection result of the temperature detection device, and selectively connects the in-vehicle heating device and / or the outdoor cooling device.

6. A thermal management system for a new energy electric vehicle according to claim 1, characterized in that: The heating element is an electric heater.

7. A thermal management method for a new energy electric vehicle thermal management system according to any one of claims 1 to 6, characterized in that: The coolant is cooled by heat exchange between the evaporator in the refrigeration circulation loop and the first heat exchanger in the coolant circulation loop, the temperature of the coolant at the inlet end of the first heat exchanger is detected, and the controller compares the detected temperature with the cooling temperature control setting conditions of the battery, the motor and the electronic control unit; When the temperature of the battery, motor and electronic control unit is greater than or equal to the cooling temperature control setting condition, the corresponding power pump is started, and the compressor is turned on at the same time to perform a refrigeration cycle, and the low-temperature refrigerant in the evaporator is used to cool the coolant in the first heat exchanger, and the low-temperature coolant then flows through the second heat exchanger in the battery, motor and electronic control unit in turn to cool the battery, motor and electronic control unit; When the temperature outside the vehicle is lower than the cooling temperature control setting conditions of the battery, motor and electronic control unit, the coolant with a higher temperature after passing through the second heat exchanger in the battery, motor and electronic control unit is controlled to flow through the radiator inside the vehicle, and heat exchange is performed with the air inside the vehicle. The coolant with a higher temperature is used to heat the air in the vehicle compartment, and the vehicle compartment temperature is assisted to be adjusted, and the coolant is cooled at the same time; or, the coolant with a higher temperature after passing through the second heat exchanger in the battery, motor and electronic control unit is controlled to flow through the radiator outside the vehicle, and heat exchange is performed with the low-temperature air outside the vehicle. The coolant is cooled by the radiator outside the vehicle. When the detected temperature is higher than the cooling temperature control setting conditions, the compressor in the refrigeration cycle is turned on, and the refrigerant is used to cool the coolant; When the temperature of the battery is lower than the heating temperature control setting condition, the electric heater is powered on for heating, and at the same time the battery heating circuit is cut off from the rest of the coolant circulation circuit, forming an independent heating cycle. The heated coolant enters the second heat exchanger inside the battery under the action of the power pump to heat the battery (1), and the coolant with a lower temperature flowing out of the second heat exchanger is heated by the electric heater again, forming an independent heating cycle.

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