Battery thermal management method and system using Peltier effect

Abstract

The invention discloses a battery thermal management method and system using a Peltier effect, and the management method, and the method comprises the steps: setting a plurality of thermoelectric modules based on the Peltier effect, enabling the two ends of each thermoelectric module to be in contact with a single battery and a liquid cooling module respectively, and enabling each single battery to be equipped with an independent thermoelectric module; the maximum temperature value, the minimum temperature value and the average temperature value of all the single batteries are collected; analyzing whether the maximum temperature value is greater than a maximum temperature threshold value, if so, controlling the thermoelectric module to be in a refrigeration mode, and if not, analyzing whether the temperature of the single battery is within a preset temperature range, and if so, analyzing whether the difference value between the maximum temperature value and the minimum temperature value is greater than a temperature difference threshold value so as to realize uniform temperature; if not, whether the temperature minimum value is smaller than the minimum temperature threshold value or not is analyzed, so that the thermoelectric module is controlled to be in a preheating mode, and the temperature of the corresponding single battery is increased. The temperature uniformity of the battery pack is improved by adjusting the temperature of the single batteries, and the performance and safety of the batteries are improved.

Description

Technical Field

[0001] The present invention belongs to the field of battery thermal management, and in particular relates to a battery thermal management method and system using the Peltier effect. Background Art

[0002] With the transformation of the global energy structure and the rapid development of the new energy vehicle industry, battery technology, especially lithium-ion battery technology, has become a key factor in promoting this change. Battery performance, safety and life are important indicators to measure the maturity of battery technology, and temperature is one of the key factors affecting these indicators. During the operation of the battery, heat is generated due to internal chemical reactions and energy conversion, causing the battery temperature to rise. If the battery temperature is too high or too low, it will affect the performance and life of the battery, and may even cause safety accidents.

[0003] Liquid cooling technology has been widely used in many fields due to its efficient heat dissipation performance. However, this technology also has several shortcomings. First of all, compared with the air cooling system, although the liquid cooling system has a more significant cooling effect, the system complexity is higher and the cost is relatively expensive. In addition, the liquid cooling system has the risk of liquid leakage, and the maintenance process is complicated and costly. The introduction of the liquid cooling system will also increase the weight and volume of the battery pack, which may affect the performance and energy density of electric vehicles. In contrast, the thermoelectric module using the Peltier effect shows many advantages, such as low driving voltage, rapid cooling start, strong stability, low noise, no moving parts and internal chemical reactions. Thermoelectric cooling technology has the advantages of compact structure and silent operation. At the same time, it does not require moving parts such as compression transmission, nor does it require the use of refrigerants, so it does not produce any emissions or environmental pollution. It is an efficient and environmentally friendly all-solid-state refrigeration and thermal management solution.

[0004] By using the Peltier effect to enhance liquid cooling technology, the temperature can be precisely controlled to achieve a temperature stability better than 0.1°C, thereby quickly responding to temperature changes in the battery pack and ensuring battery performance and safety. Secondly, the combination of the Peltier effect and the liquid cooling system improves the efficiency of heat conduction. The liquid cooling system removes heat through liquid circulation, while the thermoelectric module provides additional cooling or heating in local areas through the Peltier effect, optimizing the temperature distribution. In addition, the thermoelectric module can independently control the temperature of each battery and improve the temperature uniformity in the battery pack, which is crucial to extending battery life and enhancing battery performance. The cooling power and optimal operating current of the Peltier effect can be adjusted according to different operating conditions and temperature requirements, thereby reducing energy consumption and reducing overall heat dissipation or heating requirements. Summary of the invention

[0005] The purpose of the present invention is to overcome the above problems existing in the prior art and provide a battery thermal management method and system using the Peltier effect to solve the problems of low heat dissipation efficiency, uneven battery pack temperature and inability to preheat in a single battery thermal management system.

[0006] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0007] A battery thermal management method using the Peltier effect, comprising:

[0008] Based on the Peltier effect, several thermoelectric modules are set up, and the two ends of the thermoelectric modules are respectively in contact with the single battery and the liquid cooling module, and each single battery is equipped with an independent thermoelectric module;

[0009] Collect the maximum temperature, minimum temperature and average temperature of all single cells;

[0010] Analyze whether the maximum temperature is greater than the maximum temperature threshold. If so, control the thermoelectric module to the cooling mode to reduce the temperature of the corresponding single battery. Otherwise:

[0011] Analyze whether the temperature of the single battery is within the preset temperature range. If so, analyze whether the difference between the maximum temperature and the minimum temperature is greater than the temperature difference threshold to achieve temperature uniformity. Otherwise:

[0012] It is analyzed whether the minimum temperature value is less than the minimum temperature threshold value, so as to control the thermoelectric module to be in a preheating mode to increase the temperature of the corresponding single battery.

[0013] Further, analyzing whether the difference between the maximum temperature and the minimum temperature is greater than the temperature difference threshold includes:

[0014] If so, the thermoelectric module corresponding to the single cell whose temperature is greater than the average temperature is controlled to be in cooling mode, and the thermoelectric module corresponding to the single cell whose temperature is less than the average temperature is controlled to be in preheating mode;

[0015] If not, the control turns off the thermoelectric module and the liquid cooling module.

[0016] Furthermore, in the cooling mode, a forward current is passed, and the side of the thermoelectric module close to the single cell becomes the cold end; in the preheating mode, the current direction is changed, and the side of the thermoelectric module close to the single cell becomes the hot end.

[0017] Furthermore, the liquid cooling module is connected to a water pump. When the cooling mode or the preheating mode is turned on, the water pump is turned on so that the liquid cooling module increases the cooling rate of the hot end of the thermoelectric module in the cooling mode, or the liquid cooling module provides heat to the cold end of the thermoelectric module and accelerates heat transfer at the hot end in the preheating mode.

[0018] Furthermore, the maximum temperature, the minimum temperature and the average temperature of all the single cells are collected by positive temperature coefficient thermistors.

[0019] Furthermore, the temperature difference threshold is 5°C.

[0020] The present invention also provides a battery thermal management system using the Peltier effect, comprising:

[0021] The thermoelectric module has two ends that are in contact with the single battery and the liquid cooling module respectively;

[0022] A water pump, used to control the liquid cooling module to realize internal fluid circulation;

[0023] Temperature measurement module, used to collect the maximum temperature, minimum temperature and average temperature of all single cells;

[0024] The external control module is used to analyze whether the maximum temperature is greater than the maximum temperature threshold. If so, the thermoelectric module is controlled to be in cooling mode to reduce the temperature of the corresponding single battery. If not, the temperature of the single battery is analyzed to see whether it is within a preset temperature range. If so, the difference between the maximum temperature and the minimum temperature is analyzed to see whether it is greater than the temperature difference threshold to achieve uniform temperature. If not, the minimum temperature is analyzed to see whether it is less than the minimum temperature threshold, thereby controlling the thermoelectric module to be in preheating mode to increase the temperature of the corresponding single battery.

[0025] The power supply is respectively connected to the thermoelectric module, the water pump, the temperature measurement module and the external control module.

[0026] Furthermore, the thermoelectric module includes thermoelectric structures installed on two sides of the single battery cell, and the liquid cooling module includes a liquid cooling shell installed outside the thermoelectric structure and a liquid cooling fluid passing through the liquid cooling shell.

[0027] Furthermore, the thermoelectric structure includes an N-type semiconductor and a P-type semiconductor connected in series and parallel, so that the inner side of the thermoelectric structure becomes a cold end when a forward current flows into the structure, and becomes a hot end when the current direction is changed.

[0028] Furthermore, a fluid cavity for accommodating liquid cooling fluid is provided through the interior of the liquid cooling shell and is connected to a water pump.

[0029] The beneficial effects of the present invention are:

[0030] 1. The present invention monitors the temperature of the single cell in real time and controls the temperature of the single cell to ensure that the battery pack always operates in the optimal temperature range, thereby effectively improving the performance and safety of the battery. In addition, the system adjusts the current of different thermoelectric modules to reduce the temperature difference inside the battery pack, significantly improving the temperature uniformity, avoiding local overheating or overcooling, and protecting the battery from thermal damage.

[0031] 2. The present invention has the ability to dissipate heat quickly, and utilizes the Peltier effect to enhance the heat transfer between the battery and the liquid cooling system. At the same time, the thermoelectric cooling itself can also cool, thereby improving the heat dissipation capacity of the system under double cooling;

[0032] 3. The present invention has the ability of rapid preheating, and can accelerate the transfer of heat in the liquid cooling system to the battery by using the Peltier effect; at the same time, the thermoelectric module itself can also provide heat; the thermal management system combining the two has higher efficiency and better effect than the thermal management system of a single method.

[0033] 4. The design of the present invention reduces battery damage caused by abnormal temperature, thereby reducing the cost of maintenance and battery replacement. At the same time, the intelligent control logic of the external control module can automatically adjust the working mode according to real-time temperature data, reducing human intervention and improving the automation of the system.

[0034] In summary, the power battery thermal management system of the present invention not only improves the performance and safety of the battery through precise temperature control and intelligent management, but also extends the battery life, and has significant economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0036] Figure 1 is a flow chart of the battery thermal management method of the present invention;

[0037] Figure 2 It is a structural block diagram of the battery thermal management system of the present invention;

[0038] Figure 3 It is a schematic diagram of the installation structure of the thermoelectric module and the liquid cooling module of the present invention;

[0039] Figure 4 It is a top view of the installation structure of the thermoelectric module and the liquid cooling module of the present invention;

[0040] Figure 5 It is a side view of the installation structure of the thermoelectric module and the liquid cooling module of the present invention;

[0041] Figure 6 It is a schematic diagram of the thermoelectric structure of the present invention;

[0042] Figure 7 This is an example diagram of battery temperature changes under three different heat dissipation methods;

[0043] Figure 8 This is a comparison of the heat dissipation effects of thermoelectric refrigeration and liquid-cooled composite thermoelectric refrigeration under different current sizes;

[0044] Fig. 9 1 is an example diagram of battery temperature change under three different heating methods of the present invention. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] like Figure 1 A battery thermal management method using the Peltier effect is shown, which specifically includes the following steps:

[0047] Step 1: Based on the Peltier effect, a number of thermoelectric modules are arranged, with both ends of the thermoelectric modules contacting the single battery and the liquid cooling module respectively, and each single battery is equipped with an independent thermoelectric module;

[0048] Step 2: Collect the maximum temperature T of all single cells through positive temperature coefficient thermistor (PTC) n-max , minimum temperature T n-min And the average temperature T n-avg ; Where n- represents the battery number, the external control module compares T b-min and T b-max To determine the working mode of the thermoelectric module, T b-min and T b-max They are the maximum temperature threshold and the minimum temperature threshold of the optimal operating temperature range of the battery respectively;

[0049] Step 3: Analyze the maximum temperature T n-max Is it greater than the maximum temperature threshold T b-max If yes, the thermoelectric module is controlled to be in cooling mode to reduce the temperature of the corresponding single cell. In cooling mode, a forward current is passed through the thermoelectric module, and the side close to the single cell becomes the cold end. The water pump is started, and the heat generated by the hot end is dissipated by the liquid cooling plate, so that the temperature difference between the hot and cold ends is reduced, and the cooling efficiency is increased; if no:

[0050] Step 4: Analyze whether the temperature of the single cell is within the preset temperature range. If so, analyze the maximum temperature T n-max With minimum temperature T n-min Is the difference greater than the temperature difference threshold, for example, the temperature difference threshold is 5°C: If so, T n-max -T n-min >5℃, but T n-min >T b-min , T n-max <Tb-max , indicating that the temperature uniformity of the battery pack is poor at this time, so the thermoelectric module corresponding to the single battery whose temperature is greater than the temperature average is in cooling mode. n-avg The thermoelectric module of the battery provides a small forward current for cooling, and the corresponding thermoelectric module of the single battery whose temperature is less than the average temperature is in preheating mode. n-avg The thermoelectric module provides a large reverse current for heating until T n-max -T n-min <5℃; if not, the thermoelectric module and liquid cooling module are controlled to be turned off to achieve uniform temperature;

[0051] If otherwise:

[0052] Step 5: Analyze the minimum temperature T n-min Is it less than the minimum temperature threshold T? b-min , thereby controlling the thermoelectric module to the preheating mode to increase the temperature of the corresponding single cell. The preheating mode changes the direction of the current. The side of the thermoelectric module close to the single cell becomes the hot end. The water pump is started to maintain the temperature of the cold end so that it does not continue to drop, thereby reducing the temperature difference between the hot and cold ends and increasing the preheating efficiency.

[0053] Among them, the liquid cooling module is connected to a water pump. When the cooling mode or preheating mode is turned on, the water pump is turned on so that the liquid cooling module increases the cooling rate of the hot end of the thermoelectric module in the cooling mode, or the liquid cooling module provides heat to the cold end of the thermoelectric module in the preheating mode and accelerates the heat transfer of the hot end.

[0054] like Figure 2-9 As shown, the second aspect of the present invention also provides a battery thermal management system using the Peltier effect, comprising:

[0055] The thermoelectric module has two ends that are in contact with the single battery and the liquid cooling module respectively;

[0056] A water pump, used to control the liquid cooling module to realize internal fluid circulation;

[0057] Temperature measurement module, used to collect the maximum temperature, minimum temperature and average temperature of all single cells;

[0058] The external control module is used to analyze whether the maximum temperature is greater than the maximum temperature threshold. If so, the thermoelectric module is controlled to be in cooling mode to reduce the temperature of the corresponding single battery. If not, the temperature of the single battery is analyzed to see whether it is within a preset temperature range. If so, the difference between the maximum temperature and the minimum temperature is analyzed to see whether it is greater than the temperature difference threshold to achieve uniform temperature. If not, the minimum temperature is analyzed to see whether it is less than the minimum temperature threshold, thereby controlling the thermoelectric module to be in preheating mode to increase the temperature of the corresponding single battery.

[0059] The power supply is respectively connected to the thermoelectric module, the water pump, the temperature measurement module and the external control module.

[0060] The specific structure is as follows: the thermoelectric module includes a thermoelectric structure 1 installed on both sides of the single battery 3 relatively, and the liquid cooling module includes a liquid cooling shell 2 installed outside the thermoelectric structure 1 and a liquid cooling fluid passing through the inside of the liquid cooling shell 2.

[0061] The thermoelectric structure 1 includes an N-type semiconductor 11 and a P-type semiconductor 12 connected in series and parallel, so that the inner side of the thermoelectric structure 1 becomes a cold end when a forward current flows, and becomes a hot end when the current direction is changed.

[0062] A fluid cavity 21 for containing liquid cooling fluid is provided through the liquid cooling housing 2 and is connected to a water pump.

[0063] The battery thermal management system includes a battery pack and multiple identical heat treatment units. The battery pack is composed of several single cells 3 connected in series and parallel, and the space between the single cells 3 is filled with thermal conductive silica gel to optimize heat conduction. Each single cell 3 is equipped with an independent heat treatment unit, which is composed of a liquid cooling module, a thermoelectric module, a temperature measurement module and an external control module. First, the temperature measurement module monitors the battery temperature in real time. Once the highest temperature (T n-max ) exceeds the preset maximum safe battery temperature (T b-max ), the external control module responds immediately, controls the power supply to supply forward current to the thermoelectric module, and starts the liquid cooling module. At this time, the thermoelectric module starts to work, and through the Peltier effect, the temperature of the heat conduction plate close to the battery side gradually decreases, while the temperature of the heat conduction plate on the other side (that is, the side close to the liquid cooling plate) increases accordingly. This temperature difference prompts the thermoelectric module to transfer heat efficiently, absorbing heat from the battery end and transferring it to the liquid cooling plate end, thereby accelerating the reduction of the battery temperature. At the same time, the cold end of the thermoelectric module itself is also dissipating heat for the battery, and the amount of heat dissipation is positively correlated with the amount of current passed. Under the dual heat dissipation of liquid cooling and thermoelectric modules, the temperature of the battery can be precisely controlled. When the lowest temperature detected (T n-min ) is lower than the minimum value of the battery operating temperature range (T b-min), the external control module will control the power supply, change the direction of the current entering the thermoelectric module, and use the heating function of the thermoelectric module to increase the temperature of the heat conduction plate on one side of the battery. At the same time, the liquid cooling module will be set to the fluid circulation heating mode. The cold end of the thermoelectric module absorbs heat and transfers the heat to the hot end close to the battery side, accelerating the heat transfer between the fluid and the battery, and realizing the preheating of the battery. Since each single battery has an independent heat treatment unit, the temperature of each battery can be independently controlled, which improves the temperature uniformity in the battery pack, extends the battery life, and enhances the battery performance. Compared with single liquid cooling or thermoelectric cooling, the battery thermal management system that uses the Peltier effect to enhance liquid cooling and achieve preheating has improved the cooling and preheating effects by 13.26% and 17.23%, respectively.

[0064] The third aspect of the present invention also provides a computer storage medium on which a computer program is stored, and the computer program implements the above method when executed. The storage medium may include: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and other media that can store program codes.

[0065] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0066] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A battery thermal management method using the Peltier effect, characterized in that: include: Based on the Peltier effect, several thermoelectric modules are set up, and the two ends of the thermoelectric modules are respectively in contact with the single battery and the liquid cooling module, and each single battery is equipped with an independent thermoelectric module; Collect the maximum temperature, minimum temperature and average temperature of all single cells; Analyze whether the maximum temperature is greater than the maximum temperature threshold. If so, control the thermoelectric module to the cooling mode to reduce the temperature of the corresponding single battery. Otherwise: Analyze whether the temperature of the single battery is within the preset temperature range. If so, analyze whether the difference between the maximum temperature and the minimum temperature is greater than the temperature difference threshold to achieve temperature uniformity. Otherwise: It is analyzed whether the minimum temperature value is less than the minimum temperature threshold value, so as to control the thermoelectric module to be in a preheating mode to increase the temperature of the corresponding single battery.

2. A battery thermal management method using the Peltier effect according to claim 1, characterized in that: Analyzing whether the difference between the maximum temperature and the minimum temperature is greater than the temperature difference threshold includes: If so, the thermoelectric module corresponding to the single cell whose temperature is greater than the average temperature is controlled to be in cooling mode, and the thermoelectric module corresponding to the single cell whose temperature is less than the average temperature is controlled to be in preheating mode; If not, the control turns off the thermoelectric module and the liquid cooling module.

3. A battery thermal management method using the Peltier effect according to claim 2, characterized in that: In cooling mode, forward current is passed, and the side of the thermoelectric module close to the single cell becomes the cold end; in preheating mode, the current direction is changed, and the side of the thermoelectric module close to the single cell becomes the hot end.

4. The battery thermal management method using the Peltier effect according to claim 2, characterized in that: The liquid cooling module is connected to a water pump. When the cooling mode or preheating mode is turned on, the water pump is turned on so that the liquid cooling module increases the cooling rate of the hot end of the thermoelectric module in the cooling mode, or the liquid cooling module provides heat to the cold end of the thermoelectric module and accelerates the heat transfer of the hot end in the preheating mode.

5. A battery thermal management method using the Peltier effect according to any one of claims 1 to 4, characterized in that: The maximum temperature, minimum temperature and average temperature of all single cells are collected through positive temperature coefficient thermistors.

6. A battery thermal management method using the Peltier effect according to any one of claims 1 to 4, characterized in that: The temperature difference threshold is 5°C.

7. A battery thermal management system using the Peltier effect, characterized in that: include: The thermoelectric module has two ends that are in contact with the single battery and the liquid cooling module respectively; A water pump, used to control the liquid cooling module to realize internal fluid circulation; Temperature measurement module, used to collect the maximum temperature, minimum temperature and average temperature of all single cells; The external control module is used to analyze whether the maximum temperature is greater than the maximum temperature threshold. If so, the thermoelectric module is controlled to be in cooling mode to reduce the temperature of the corresponding single battery. If not, analyze whether the temperature of the single battery is within a preset temperature range. If so, analyze whether the difference between the maximum temperature and the minimum temperature is greater than the temperature difference threshold to achieve temperature uniformity. If not, analyze whether the minimum temperature is less than the minimum temperature threshold, thereby controlling the thermoelectric module to be in preheating mode to increase the temperature of the corresponding single battery. The power supply is respectively connected to the thermoelectric module, the water pump, the temperature measurement module and the external control module.

8. A battery thermal management system using the Peltier effect according to claim 7, characterized in that: The thermoelectric module comprises a thermoelectric structure (1) installed on both sides of a single battery (3) relatively to each other, and the liquid cooling module comprises a liquid cooling shell (2) installed outside the thermoelectric structure (1) and a liquid cooling fluid passing through the interior of the liquid cooling shell (2).

9. A battery thermal management system using the Peltier effect according to claim 8, characterized in that: The thermoelectric structure (1) comprises an N-type semiconductor (11) and a P-type semiconductor (12) connected in series and parallel, so that when a forward current flows through the thermoelectric structure (1), the inner side becomes a cold end, and when the current direction is changed, the inner side becomes a hot end.

10. A battery thermal management system using the Peltier effect according to claim 8, characterized in that: A fluid cavity (21) for accommodating a liquid cooling fluid is provided through the interior of the liquid cooling housing (2) and is connected to a water pump.

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