Power battery thermal management method and device

Abstract

The present invention discloses a power battery thermal management method and device, the method comprising: collecting a first temperature of a power battery and a second temperature inside a vehicle compartment; if the first temperature of the power battery is greater than a maximum value of a preset battery temperature range, transferring the heat generated by the power battery through a heat pipe, and when the heat generated by the power battery exceeds the heat conductivity of the heat pipe, auxiliary heat dissipation of the power battery is performed through a liquid cooling pipe; if the first temperature of the power battery is less than a minimum value of a preset battery temperature range, and the second temperature inside the vehicle compartment is less than a minimum value of a preset vehicle interior temperature range, heating the interior of the vehicle compartment through a heat pump, and partially transferring the heat inside the vehicle compartment to the power battery through the heat pipe; the present invention uses heat pipes as the main heat dissipation method of the power battery and liquid cooling pipes as the auxiliary heat dissipation method of the power battery, which can effectively reduce the liquid cooling heat dissipation pressure of the battery, and when the heat pump heats the interior of the vehicle compartment, effectively reduce the battery heating energy consumption.

Description

Technical Field

[0001] The present invention relates to the technical field of power battery thermal management, and in particular to a power battery thermal management method and device. Background Art

[0002] Due to the low temperature attenuation of electric vehicle power batteries, working heat dissipation problems, and automobile air conditioning heating, cooling, dehumidification and defogging problems, the battery life of electric vehicles is affected, especially in winter, because the power battery heating and air conditioning heating functions need to be started at the same time, resulting in a serious reduction in the battery life of electric vehicles.

[0003] At present, the thermal management system of electric vehicle power battery and the vehicle air conditioning system are independent of each other. Electric vehicles cannot use the engine waste heat for heating like fuel vehicles, which leads to energy waste and other problems. At present, electric vehicle power batteries generally use PTC electric heating for heat preservation + coolant for heat dissipation. Air conditioners generally use PTC electric heating or electric heat pumps. However, the efficiency of PTC electric heating is too low; and the electric heat pump is based on the reverse Carnot cycle, which is heavy and has problems such as frost affecting heating in severe cold, resulting in high energy consumption of electric vehicles. Summary of the invention

[0004] The purpose of the present invention is to provide a power battery thermal management method and device, which uses heat pipes as the main heat dissipation method of the power battery and liquid cooling pipes as the auxiliary heat dissipation method of the power battery, which can effectively reduce the liquid cooling heat dissipation pressure of the battery, and when the heat pump heats the interior of the vehicle compartment, the heat inside the vehicle compartment is partially transferred to the power battery through the heat pipe, thereby reducing the energy consumption required to heat the power battery in winter, thereby effectively reducing the heat load energy consumption and effectively improving the endurance of the power battery.

[0005] In order to achieve the above object, the present invention discloses a power battery thermal management method, which is applicable to an electric vehicle, wherein the electric vehicle is provided with a heat pipe that can selectively direct the heat of the power battery to the inside or outside of the vehicle compartment, and the power battery thermal management method comprises the following steps:

[0006] S1. collecting a first temperature of the power battery and a second temperature inside the vehicle compartment;

[0007] S2. If the first temperature of the power battery is greater than the maximum value of the preset battery temperature range, the heat generated by the power battery is transferred through the heat pipe, and when the heat generated by the power battery exceeds the heat conductivity of the heat pipe, the power battery is assisted in heat dissipation through the liquid cooling pipe;

[0008] S3. If the first temperature of the power battery is lower than the minimum value of the preset battery temperature range, and the second temperature inside the vehicle compartment is lower than the minimum value of the preset vehicle interior temperature range, the interior of the vehicle compartment is heated by a heat pump, and part of the heat inside the vehicle compartment is transferred to the power battery through a heat pipe.

[0009] Compared with the prior art, the electric vehicle of the present invention is provided with a heat pipe which can selectively direct the heat of the power battery to the interior or exterior of the vehicle compartment. If the first temperature of the power battery is greater than the maximum value of a preset battery temperature range, the heat generated by the power battery is transferred through the heat pipe, and when the heat generated by the power battery exceeds the heat conductivity of the heat pipe, the power battery is assisted in heat dissipation through the liquid cooling pipe. If the first temperature of the power battery is less than the minimum value of the preset battery temperature range, and the second temperature inside the vehicle compartment is less than the minimum value of the preset vehicle interior temperature range, the interior of the vehicle compartment is heated by a heat pump, and part of the heat inside the vehicle compartment is transferred to the power battery through the heat pipe. On the one hand, using the heat pipe as the main heat dissipation method of the power battery and the liquid cooling pipe as the auxiliary heat dissipation method of the power battery can effectively reduce the liquid cooling heat dissipation pressure of the battery; on the other hand, when the heat pump heats the interior of the vehicle compartment, part of the heat inside the vehicle compartment is transferred to the power battery through the heat pipe, thereby reducing the energy consumption required to heat the power battery in winter, thereby effectively reducing the heat load energy consumption and effectively improving the endurance of the power battery.

[0010] Preferably, the step S1 further comprises:

[0011] The frost and fog status of the front windshield is also collected.

[0012] Preferably, in the step S2, if the first temperature of the power battery is greater than the maximum value of the preset battery temperature range, the heat generated by the power battery is transferred through the heat pipe, further comprising:

[0013] When the front windshield is in a frosted state, the heat pipe transfers part of the heat generated by the power battery to the front windshield to remove the frosted state of the front windshield;

[0014] When the front windshield is not in a frosted state and the second temperature inside the vehicle compartment is greater than the maximum value of a preset vehicle interior temperature range, the heat pipe transfers the heat generated by the power battery to the external environment.

[0015] Preferably, the step S3 further comprises:

[0016] When the second temperature inside the vehicle compartment rises to a preset vehicle compartment temperature range, the power battery is assisted in cooling through the liquid cooling pipe.

[0017] Preferably, the power battery thermal management method further comprises the following steps:

[0018] When the electric vehicle needs to be started from cold, if the first temperature of the power battery is lower than the minimum value of the preset battery temperature range and there is a heating demand inside the vehicle cabin, the heat pump is used to heat the interior of the vehicle cabin and the power battery is heated by the PTC heating device.

[0019] Preferably, the step S3 further comprises:

[0020] When the thermal conductivity of the heat pipe is lower than the cold load of the power battery, the PTC heating device is started to assist in heating the power battery.

[0021] Preferably, the heat pipe is a vacuum copper tube with a closed structure, the copper tube is filled with an inert liquid, and the interior of the vacuum copper tube is a capillary structure.

[0022] Specifically, the heat pipe is divided into an evaporation heat absorption section, an insulation section and a condensation heat release section in sequence, and the condensation heat release section protrudes along the circumferential direction to form heat dissipation fins.

[0023] Specifically, the power battery and the liquid cooling tube are distributed around the evaporation heat absorption section, and the power battery and the liquid cooling tube are respectively in contact with the evaporation heat absorption section through heat-conductive silica gel.

[0024] Accordingly, the present invention further discloses a power battery thermal management device, which is applicable to an electric vehicle, wherein the electric vehicle is provided with a heat pipe that can selectively direct the heat of the power battery to the interior or exterior of the vehicle compartment, and the power battery thermal management device comprises:

[0025] a collecting unit configured to collect a first temperature of the power battery and a second temperature inside the vehicle compartment;

[0026] a first processing unit configured to transfer heat generated by the power battery through the heat pipe if the first temperature of the power battery is greater than a maximum value of a preset battery temperature range, and to assist in cooling the power battery through the liquid cooling pipe when the heat generated by the power battery exceeds the heat conductivity of the heat pipe;

[0027] The second processing unit is configured to heat the interior of the vehicle cabin through a heat pump and transfer part of the heat inside the vehicle cabin to the power battery through a heat pipe if the first temperature of the power battery is lower than a minimum value of a preset battery temperature range and the second temperature inside the vehicle cabin is lower than a minimum value of a preset vehicle interior temperature range. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a flowchart of the power battery thermal management method of the present invention;

[0029] Figure 2 It is a schematic diagram of the structure of the heat pipe, power battery and liquid cooling pipe of the present invention;

[0030] Figure 3 It is a structural block diagram of the power battery thermal management device of the present invention. DETAILED DESCRIPTION

[0031] In order to explain the technical content, structural features, achieved objectives and effects of the present invention in detail, the following is a detailed description in conjunction with the implementation methods and the accompanying drawings.

[0032] See also Figure 1 and Figure 2 As shown, the power battery thermal management method of this embodiment is applicable to an electric vehicle, wherein the electric vehicle is provided with a heat pipe 200 which can selectively direct the heat of the power battery 100 to the interior or exterior of the vehicle compartment, and the electric vehicle is provided with a heat pump, a liquid cooling pipe 300 and a PTC heating device, wherein the heat pump can be used to heat the interior of the vehicle compartment, the liquid cooling pipe 300 can be used to dissipate heat from the power battery 100, and the PTC heating device can be used to heat the power battery 100.

[0033] The power battery thermal management method comprises the following steps:

[0034] S1. Collecting a first temperature of the power battery 100 and a second temperature inside the vehicle compartment.

[0035] The first temperature here is specifically the real-time temperature inside or on the surface of the power battery 100 , and the second temperature is specifically the real-time temperature inside the vehicle compartment.

[0036] S2. If the first temperature of the power battery 100 is greater than the maximum value of the preset battery temperature range, the heat generated by the power battery 100 is transferred through the heat pipe 200, and when the heat generated by the power battery 100 exceeds the heat conductivity of the heat pipe 200, the liquid cooling pipe 300 is used to assist in heat dissipation of the power battery 100.

[0037] It is understandable that when the electric vehicle is running, as the power consumption time and power consumption increase, the first temperature of the power battery 100 will become higher and higher. When the first temperature of the power battery 100 is greater than the maximum value of the preset battery temperature range, the present embodiment uses the heat pipe 200 as the main heat dissipation method of the power battery 100, and when the heat generated by the power battery 100 exceeds the heat conductivity of the heat pipe 200, the liquid cooling pipe 300 is activated to assist in the heat dissipation of the power battery 100, thereby avoiding the situation in traditional electric vehicles where the liquid cooling pipe 300 is directly activated to dissipate heat for the power battery 100 when the real-time temperature of the power battery 100 is higher than the preset value, thereby effectively reducing the heat dissipation pressure of the liquid cooling pipe 300 and reducing the energy consumption of the liquid cooling pipe 300.

[0038] S3. If the first temperature of the power battery 100 is lower than the minimum value of the preset battery temperature range, and the second temperature inside the vehicle compartment is lower than the minimum value of the preset vehicle interior temperature range, the interior of the vehicle compartment is heated by a heat pump, and part of the heat inside the vehicle compartment is transferred to the power battery 100 through the heat pipe 200.

[0039] It is understandable that when the vehicle is used in winter, the second temperature inside the vehicle compartment is relatively low, and the heat pump is required to heat the vehicle compartment to improve the comfort of the passengers inside the vehicle compartment. However, since the heat generated by the power battery 100 is lower than the ambient temperature during the use of the vehicle in winter, the power battery 100 cannot work in an optimal temperature environment. At this time, the present embodiment transfers part of the heat inside the vehicle compartment to the power battery 100 through the heat pipe 200 to ensure that the power battery 100 can work in an optimal temperature environment. The heating process of the power battery 100 directly uses the heat pump inside the vehicle compartment for preheating, and there is no need to use an additional heating device to heat the power battery 100, which effectively reduces the heating energy consumption.

[0040] Preferably, the step S1 further comprises:

[0041] The frost and fog status of the front windshield is also collected.

[0042] Preferably, in the step S2, if the first temperature of the power battery 100 is greater than the maximum value of the preset battery temperature range, the heat generated by the power battery 100 is transferred through the heat pipe 200, further comprising:

[0043] When the front windshield is in a frosted state, the heat pipe 200 transfers part of the heat generated by the power battery 100 to the front windshield to remove the frosted state of the front windshield;

[0044] When the front windshield is not in a frosted state, the heat pipe 200 transfers the heat generated by the power battery 100 to the external environment.

[0045] Preferably, the step S3 further comprises:

[0046] When the second temperature inside the vehicle compartment rises to a preset vehicle compartment temperature range, the power battery 100 is assisted in cooling down through the liquid cooling pipe 300 .

[0047] It is understandable that when the second temperature inside the vehicle compartment rises to a preset vehicle temperature range, the air conditioning will be started inside the vehicle compartment to cool down, and at the same time, the heat pipe 200 will transfer part of the cold air inside the vehicle compartment to the power battery 100. At this time, the liquid cooling pipe 300 can also be started to assist in cooling the power battery 100 to ensure the normal operation of the power battery 100.

[0048] Preferably, the power battery thermal management method further comprises the following steps:

[0049] When the electric vehicle needs to be started from a cold state, if the first temperature of the power battery 100 is less than the minimum value of the preset battery temperature range and there is a heating demand inside the vehicle compartment, the heat pump is used to heat the vehicle compartment, and the power battery 100 is heated by the PTC heating device. The power battery 100 is heated by the PTC heating device to quickly increase the first temperature of the power battery 100 when the vehicle is started from a cold state, ensuring that the power battery 100 can quickly enter a better temperature environment. The action time of the PTC heating device in this process is short and will not have a significant impact on the overall endurance.

[0050] Preferably, the step S3 further comprises:

[0051] When the thermal conductivity of the heat pipe 200 is lower than the cold load of the power battery 100 , the PTC heating device is started to perform auxiliary heating on the power battery 100 .

[0052] Preferably, the heat pipe 200 is a closed vacuum copper tube with uniform temperature, the copper tube is filled with an inert liquid, and the interior of the vacuum copper tube is a capillary structure. The inert liquid here is a liquid such as a working fluid fluoride or water, which has a high thermal conductivity.

[0053] Specifically, the heat pipe 200 is divided into an evaporation heat absorption section 210, an insulation section 220 and a condensation heat release section 230 in sequence. The condensation heat release section 230 protrudes circumferentially to form heat dissipation fins 240 to increase convection heat exchange between the heat pipe 200 and the air.

[0054] Specifically, the power battery 100 and the liquid cooling tube 300 are distributed around the evaporation heat absorption section 210, and the power battery 100 and the liquid cooling tube 300 are respectively in contact with the evaporation heat absorption section 210 through the thermal conductive silica gel 400. The coolant of the liquid cooling tube 300 adopts immersion cooling technology, and uses a battery core coolant such as a fluorinated liquid, which can play an excellent role in heat conduction, insulation, stability and non-flammability, so as to achieve uniform temperature between battery cells and improve the life of the power battery 100. The thermal conductive glue here is preferably TIF thermal conductive glue, which can enhance the thermal conductivity of the heat pipe 200 and the power battery 100.

[0055] When the power battery 100 generates heat, the heating end of the heat pipe 200 reaches the phase change temperature, and the working fluid at this end evaporates to take away the heat. The steam working fluid flows through the central channel of the heat pipe 200 to the condensation heat release section 230 of the heat pipe 200 to condense, releases heat in the condensation heat release section 230, and heats the surrounding air through the fins. Under the action of capillary force and gravity, the inert liquid in the heat pipe 200 flows back to the evaporation heat absorption section 210, realizing a continuous cycle.

[0056] See also Figure 1-Figure 3As shown, the present invention also discloses a power battery thermal management device, which is applicable to an electric vehicle, wherein the electric vehicle is provided with a heat pipe 200 that can selectively direct the heat of the power battery 100 to the interior or exterior of the vehicle compartment, and the power battery thermal management device comprises:

[0057] The collecting unit 10 is configured to collect a first temperature of the power battery 100 and a second temperature inside the vehicle compartment;

[0058] The first processing unit 20 is configured to transfer the heat generated by the power battery 100 through the heat pipe 200 if the first temperature of the power battery 100 is greater than the maximum value of the preset battery temperature range, and to assist in heat dissipation of the power battery 100 through the liquid cooling pipe 300 when the heat generated by the power battery 100 exceeds the heat conductivity of the heat pipe 200;

[0059] The second processing unit 30 is configured to heat the interior of the vehicle cabin through a heat pump and transfer part of the heat inside the vehicle cabin to the power battery 100 through the heat pipe 200 if the first temperature of the power battery 100 is lower than the minimum value of the preset battery temperature range and the second temperature inside the vehicle cabin is lower than the minimum value of the preset vehicle cabin temperature range.

[0060] Combination Figure 1-Figure 3 The electric vehicle of the present invention is provided with a heat pipe 200 that can selectively direct the heat of the power battery 100 to the interior or exterior of the vehicle compartment. If the first temperature of the power battery 100 is greater than the maximum value of the preset battery temperature range, the heat generated by the power battery 100 is transferred through the heat pipe 200, and when the heat generated by the power battery 100 exceeds the heat conduction capacity of the heat pipe 200, the power battery 100 is assisted in heat dissipation through the liquid cooling pipe 300. If the first temperature of the power battery 100 is less than the minimum value of the preset battery temperature range, and the second temperature inside the vehicle compartment is less than the minimum value of the preset vehicle interior temperature range, the heat generated by the power battery 100 is transferred through the heat pipe 200. The heat pump heats the interior of the vehicle compartment and transfers part of the heat inside the vehicle compartment to the power battery 100 through the heat pipe 200. On the one hand, the heat pipe 200 is used as the main heat dissipation method of the power battery 100, and the liquid cooling pipe 300 is used as the auxiliary heat dissipation method of the power battery 100, which can effectively reduce the liquid cooling heat dissipation pressure of the battery; on the other hand, when the heat pump heats the interior of the vehicle compartment, part of the heat inside the vehicle compartment is transferred to the power battery 100 through the heat pipe 200, reducing the energy consumption required to heat the power battery 100 in winter, thereby effectively reducing the heat load energy consumption and effectively improving the endurance of the power battery 100.

[0061] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. A power battery thermal management method, applicable to electric vehicles, characterized in that: The electric vehicle is provided with a heat pipe that can selectively direct the heat of the power battery to the interior or exterior of the vehicle compartment. The power battery heat management method comprises the following steps: collecting a first temperature of the power battery and a second temperature inside the vehicle compartment; If the first temperature of the power battery is greater than the maximum value of the preset battery temperature range, the heat generated by the power battery is transferred through the heat pipe, and when the heat generated by the power battery exceeds the heat conductivity of the heat pipe, the power battery is assisted in heat dissipation through the liquid cooling pipe; If the first temperature of the power battery is lower than the minimum value of the preset battery temperature range, and the second temperature inside the vehicle compartment is lower than the minimum value of the preset vehicle interior temperature range, the heat pump is used to heat the interior of the vehicle compartment, and part of the heat inside the vehicle compartment is transferred to the power battery through the heat pipe.

2. The power battery thermal management method according to claim 1, characterized in that: The collecting the first temperature of the power battery and the second temperature inside the vehicle compartment further includes: The frost and fog status of the front windshield is also collected.

3. The power battery thermal management method according to claim 2, characterized in that: If the first temperature of the power battery is greater than the maximum value of the preset battery temperature range, the heat generated by the power battery is transferred through the heat pipe, further comprising: When the front windshield is in a frosted state, the heat pipe transfers part of the heat generated by the power battery to the front windshield to remove the frosted state of the front windshield; When the front windshield is not in a frosted state and the second temperature inside the vehicle compartment is greater than the maximum value of a preset vehicle interior temperature range, the heat pipe transfers the heat generated by the power battery to the external environment.

4. The power battery thermal management method according to claim 2, characterized in that: If the first temperature of the power battery is lower than the minimum value of the preset battery temperature range, and the second temperature inside the vehicle compartment is lower than the minimum value of the preset vehicle interior temperature range, the interior of the vehicle compartment is heated by a heat pump, and part of the heat inside the vehicle compartment is transferred to the power battery by a heat pipe, further comprising: When the second temperature inside the vehicle compartment rises to a preset vehicle compartment temperature range, the power battery is assisted in cooling through the liquid cooling pipe.

5. The power battery thermal management method according to claim 1, characterized in that: The power battery thermal management method further comprises the following steps: When the electric vehicle needs to be started from cold, if the first temperature of the power battery is lower than the minimum value of the preset battery temperature range and there is a heating demand inside the vehicle cabin, the heat pump is used to heat the interior of the vehicle cabin and the power battery is heated by the PTC heating device.

6. The power battery thermal management method according to claim 1, characterized in that: If the first temperature of the power battery is lower than the minimum value of the preset battery temperature range, and the second temperature inside the vehicle compartment is lower than the minimum value of the preset vehicle interior temperature range, the interior of the vehicle compartment is heated by a heat pump, and part of the heat inside the vehicle compartment is transferred to the power battery by a heat pipe, further comprising: When the thermal conductivity of the heat pipe is lower than the cold load of the power battery, the PTC heating device is started to assist in heating the power battery.

7. The power battery thermal management method according to claim 1, characterized in that: The heat pipe is a vacuum copper tube with a closed structure. The copper tube is filled with an inert liquid, and the interior of the vacuum copper tube is a capillary structure.

8. The power battery thermal management method according to claim 7, characterized in that: The heat pipe is divided into an evaporation heat absorption section, an insulation section and a condensation heat release section in sequence, and the condensation heat release section protrudes along the circumferential direction to form heat dissipation fins.

9. The power battery thermal management method according to claim 8, characterized in that: The power battery and the liquid cooling tube are distributed around the evaporation heat absorption section, and the power battery and the liquid cooling tube are respectively in contact with the evaporation heat absorption section through heat-conducting silica gel.

10. A power battery thermal management device, suitable for electric vehicles, characterized in that: The electric vehicle is provided with a heat pipe that can selectively direct the heat of the power battery to the interior or exterior of the vehicle compartment, and the power battery thermal management device comprises: a collecting unit configured to collect a first temperature of the power battery and a second temperature inside the vehicle compartment; a first processing unit configured to transfer heat generated by the power battery through the heat pipe if the first temperature of the power battery is greater than a maximum value of a preset battery temperature range, and to assist in cooling the power battery through the liquid cooling pipe when the heat generated by the power battery exceeds the heat conductivity of the heat pipe; The second processing unit is configured to heat the interior of the vehicle cabin through a heat pump and transfer part of the heat inside the vehicle cabin to the power battery through a heat pipe if the first temperature of the power battery is lower than a minimum value of a preset battery temperature range and the second temperature inside the vehicle cabin is lower than a minimum value of a preset vehicle interior temperature range.

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