A counter-flow liquid-cooled battery management and fire extinguishing system for lithium-ion batteries

Abstract

The present invention discloses a counter-flow liquid-cooled battery management and fire extinguishing system for lithium-ion batteries, the device comprising: a liquid-cooling structure shell, a liquid-cooling plate heat exchanger and a battery unit; a liquid-cooling plate heat exchanger is installed on the upper and lower surfaces of the battery unit, the liquid-cooling structure shell wraps the battery unit and the liquid-cooling plate heat exchanger; the liquid-cooling structure shell fits the liquid-cooling plate heat exchanger. The liquid-cooling plate heat exchanger is provided with a two-way liquid-cooling pipe, and the liquid-cooling pipe is provided with an air inlet, and a fine water mist nozzle is provided on the surface of the liquid-cooling pipe; the advantages of the present invention are: the two-way flow pipe keeps the temperature difference of each part of the battery surface within a reasonable range, ensures the working performance of the battery, avoids long-term excessive temperature difference, and when the temperature is too high or a fire occurs, the fine water mist can evenly cover the entire battery surface to achieve the purpose of cooling and extinguishing the fire.

Description

Technical Field

[0001] The present invention relates to the technical field of battery thermal management, and in particular to a counter-flow liquid-cooled battery management and fire extinguishing system for lithium-ion batteries. Background Art

[0002] In recent years, with the increasing global environmental pollution and energy shortage problems, the development and use of pure electric or hybrid vehicles, aircraft, ships and other means of transportation powered by lithium-ion batteries have received widespread attention from countries around the world. Among them, due to the potential dangers of lithium-ion batteries themselves and the heat generated during rapid charging and discharging, they need to work in a relatively stable environment under the action of the battery thermal management system to enable the battery to obtain better power output characteristics, cycle life and system safety. The existing mainstream battery management technologies mainly include air cooling and liquid cooling technologies. Among them, the air cooling technology has a large difference in inlet and outlet temperatures, resulting in poor uniformity of battery heat dissipation. It is mainly suitable for application scenarios with smaller output currents, and its application value in large power output devices is relatively low. Liquid cooling technology is a battery thermal management method with a higher level of protection. The specific heat capacity of the liquid medium in the liquid cooling plate is much greater than that of air. A small flow rate can take away a large amount of heat, and can efficiently bring the heat of the battery to the outside world. It is common to place liquid cooling plates on the upper and lower surfaces of the battery to absorb the heat dissipated by the battery by controlling the circulation of the cooling medium. Due to the different inlet and outlet times of the cooling medium, the battery temperature distribution is uneven, especially the inlet and outlet temperature difference is large. This temperature unevenness causes great damage to the battery. Long-term use can easily affect the battery life due to differences in battery consistency, and even cause thermal runaway of the battery. In addition, the existing battery management system cannot effectively handle the battery after it runs away. After the battery catches fire, there is no effective measure to extinguish the flames and prevent the fire from spreading further.

[0003] The current mainstream lithium-ion battery liquid cooling technology uses a one-way flow tube on the liquid cooling plate for heat dissipation, that is, there is only one cooling medium inlet and outlet. Due to the flow rate, the cooling medium flows through the liquid cooling plate channel to dissipate heat, resulting in uneven heat dissipation and inconsistent temperatures at different parts, especially at the inlet and outlet. The temperature difference is large. Long-term uneven temperature distribution will lead to a decrease in the performance of lithium-ion batteries, and more seriously, it will lead to thermal runaway of the battery.

[0004] Therefore, we need to further research and develop a battery thermal management and fire extinguishing system that can better achieve battery temperature uniformity management while taking into account rapid cooling and fire extinguishing of the battery in the early stages of thermal runaway.

[0005] Prior art 1

[0006] Chinese invention patent: A parallel multi-channel liquid cooling structure for lithium batteries and lithium batteries, patent application number: 201911326367.1.

[0007] Disadvantages of the prior art 1

[0008] The invention adopts a one-way flow tube, which cannot completely solve the problem of uneven battery temperature distribution due to flow rate problems, especially the large temperature difference at the inlet and outlet of the vertical direct current pipe. Long-term use will reduce the service life of the battery and easily lead to thermal runaway of the battery. In this invention, when the battery temperature rises abnormally or the battery catches fire or explodes, no effective means are used to cool the battery, extinguish the fire, and prevent the spread of the fire, which is extremely dangerous.

[0009] Prior art 2

[0010] Chinese invention patent: A lithium battery liquid cooling box, patent application number: 201910767862.X.

[0011] Disadvantages of the second prior art

[0012] The invention adopts a one-way flow tube, which cannot make the surface temperature of the lithium-ion battery evenly distributed while dissipating heat, resulting in a large temperature difference between different parts of the battery surface. Long-term use affects the performance and service life of the battery, and increases the probability of thermal runaway and fire of the battery. The invention also does not have effective cooling and fire extinguishing measures. When the battery temperature is too high or catches fire, it cannot effectively reduce the temperature and extinguish the fire.

[0013] Chinese utility model patent: A safe lithium battery for electric vehicles, patent application number: 201922428162.6.

[0014] Disadvantages of the prior art 3

[0015] The utility model adopts a sealed cavity structure and uses a cooling fan to dissipate heat during the operation of the battery. Compared with water cooling, the heat dissipation effect is limited, it cannot effectively cool down, and it cannot dissipate the heat evenly on the surface temperature of the battery; a spiral nozzle is used to spray the fire extinguishing agent for fire extinguishing, which makes the battery box larger, occupies a larger space, and has a higher cost of use; compared with a high-pressure fine water mist nozzle, the spray uniformity is lower, the cooling effect is slightly worse, and it cannot block oxygen, inhibit the oxidation reaction, or block the heat transfer. Summary of the invention

[0016] In view of the defects of the prior art, the present invention provides a counter-flow liquid-cooled battery management and fire extinguishing system for lithium-ion batteries, which solves the defects in the prior art.

[0017] In order to achieve the above invention object, the technical solution adopted by the present invention is as follows:

[0018] A counter-flow liquid-cooled battery management and fire extinguishing system for lithium-ion batteries, comprising: a liquid-cooled structural housing 1, a liquid-cooled plate heat exchanger 2, and a battery unit 7;

[0019] The number of the battery cells 7 is one or more. If there are multiple battery cells, they are arranged in sequence in the same direction.

[0020] A liquid cooling plate heat exchanger 2 is installed on the upper and lower surfaces of the battery unit 7 , and the liquid cooling structure shell 1 wraps the battery unit 7 and the liquid cooling plate heat exchanger 2 ; the liquid cooling structure shell 1 fits the liquid cooling plate heat exchanger 2 .

[0021] The liquid cooling plate heat exchanger 2 includes: two liquid cooling pipes, a water pump, an air pump, a first direction inlet pipe 3, a first direction outlet pipe 4, a second direction inlet pipe 5, a second direction outlet pipe 6, a first direction air inlet 8, a second direction air inlet 9, and a fine water mist nozzle 10;

[0022] Two liquid cooling pipes are arranged side by side in an "S" shape and cover the surface of the battery unit 7. The two ends of one liquid cooling pipe are respectively connected to the first direction inlet pipe 3 and the first direction outlet pipe 4, and the two ends of the other liquid cooling pipe are respectively connected to the second direction inlet pipe 5 and the second direction outlet pipe 6. The first direction inlet pipe 3 and the second direction outlet pipe 6 are placed in parallel and in the same direction, and the first direction outlet pipe 4 and the second direction inlet pipe 5 are placed in parallel and in the same direction.

[0023] The side of the first direction inlet pipe 3 is connected to the first direction air inlet 8 , and the side of the second direction inlet pipe 5 is connected to the second direction air inlet 9 .

[0024] The first direction inlet pipe 3 and the second direction inlet pipe 5 are connected to a water pump, and the first direction air inlet 8 and the second direction air inlet 9 are connected to an air pump.

[0025] A plurality of fine water mist nozzles 10 are provided on one side of the two liquid cooling pipes facing the battery cell 7. The fine water mist nozzles 10 are reasonably spaced so that the fine water mist can be evenly distributed on the surface of the battery cell 7. The number of the fine water mist nozzles 10 can be increased or decreased according to actual needs. The fine water mist nozzles 10 are not completely in contact with the battery cell 7, and a gap is left for the fine water mist nozzles 10 to spray cooling medium.

[0026] The first direction air inlet 8, the second direction air inlet 9 and the water mist nozzle 10 are all provided with valves.

[0027] Temperature and smoke sensors are attached to the surface of the liquid cooling structure housing 1 and the battery unit 7 to monitor temperature changes and smoke.

[0028] When the temperature and smoke sensors detect an abnormal situation, which means that the battery temperature is too high or has caught fire, the temperature sensor detects an excessively high temperature or the smoke sensor detects smoke, the valves of the first direction air inlet 8 and the second direction air inlet 9 are opened, and the water pump power is increased at the same time. The flow rate of the cooling medium in the liquid cooling pipe reaches the requirement for extinguishing the fire, the valve of the fine water mist nozzle 10 is opened, and the air pump allows high-pressure gas to enter from the first direction air inlet 8 and the second direction air inlet 9, and the cooling medium is sprayed out through the fine water mist nozzle 10 to form fine water mist for cooling and extinguishing the fire. The cooling medium uses a non-flammable liquid, which includes but is not limited to water.

[0029] Furthermore, the water mist nozzle 10 adopts a four-directional nozzle.

[0030] Furthermore, the liquid cooling structure housing 1 is made of flame retardant material.

[0031] Compared with the prior art, the advantages of the present invention are:

[0032] 1. The two-way flow pipeline can keep the battery within a reasonable temperature difference range and make the battery surface temperature evenly distributed, especially the temperature difference at the inlet and outlet. While the battery is cooled quickly, the temperature difference of each part of the battery surface is kept within a reasonable range, ensuring the working performance of the battery, avoiding long-term excessive temperature difference, resulting in reduced battery service life, reduced performance, and thermal safety problems, and improving the uniformity of temperature distribution of lithium-ion batteries.

[0033] 2. Equipped with air inlet pipe and fine water mist nozzle to ensure that when the temperature is too high or a fire occurs, the fine water mist can evenly cover the entire battery surface to achieve the purpose of cooling and extinguishing the fire.

[0034] 3. The system has a high degree of integration, and the battery thermal management system is highly integrated with the fire extinguishing system, which greatly saves the system volume and weight while ensuring the system functionality and practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a schematic diagram of the overall appearance of a counter-flow liquid-cooled battery management and fire extinguishing system according to an embodiment of the present invention;

[0036] Figure 2 is an exploded schematic diagram of a counter-flow liquid-cooled battery management and fire extinguishing system according to an embodiment of the present invention;

[0037] Figure 3 is a schematic structural diagram of a liquid cooling plate heat exchanger according to an embodiment of the present invention;

[0038] Figure 4 2. It is a schematic diagram of the structure of a water mist nozzle according to an embodiment of the present invention;

[0039] In the figure: 1-liquid cooling structure shell; 2-liquid cooling plate heat exchanger; 3-first direction inlet pipe; 4-first direction outlet pipe; 5-second direction inlet pipe; 6-second direction outlet pipe; 7-battery unit; 8-first direction air inlet; 9-second direction air inlet; 10-fine water mist nozzle. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and examples.

[0041] like Figure 1 and 2 As shown, a counter-flow liquid-cooled battery management and fire extinguishing system for lithium-ion batteries comprises: a liquid-cooled structural housing 1, a liquid-cooled plate heat exchanger 2 and a battery unit 7;

[0042] A liquid-cooled plate heat exchanger 2 is installed on the upper and lower surfaces of the battery unit 7, and the liquid-cooled structure shell 1 wraps the battery unit 7 and the liquid-cooled plate heat exchanger 2; wherein the length and size of the liquid-cooled plate heat exchanger 2 are adjusted according to the battery unit 7 or multiple groups of battery units 7. The liquid-cooled structure shell 1 is made of flame-retardant material and fits the liquid-cooled plate heat exchanger 2 to hinder the spread of fire, and to insulate and prevent heat transfer from causing the temperature of the adjacent battery or battery group to be too high.

[0043] like Figure 3 As shown, the liquid cooling plate heat exchanger 2 includes: two liquid cooling pipes, a water pump, an air pump, a first direction inlet pipe 3, a first direction outlet pipe 4, a second direction inlet pipe 5, a second direction outlet pipe 6, a first direction air inlet 8, a second direction air inlet 9, and a fine water mist nozzle 10;

[0044] Two liquid cooling pipes are arranged side by side in an "S" shape and cover the surface of the battery unit 7. The two ends of one liquid cooling pipe are respectively connected to the first direction inlet pipe 3 and the first direction outlet pipe 4, and the two ends of the other liquid cooling pipe are respectively connected to the second direction inlet pipe 5 and the second direction outlet pipe 6. The first direction inlet pipe 3 and the second direction outlet pipe 6 are placed in parallel and in the same direction, and the first direction outlet pipe 4 and the second direction inlet pipe 5 are placed in parallel and in the same direction.

[0045] The side of the first direction inlet pipe 3 is connected to the first direction air inlet 8 , and the side of the second direction inlet pipe 5 is connected to the second direction air inlet 9 .

[0046] The first direction inlet pipe 3 and the second direction inlet pipe 5 are connected to a water pump, and the first direction air inlet 8 and the second direction air inlet 9 are connected to an air pump.

[0047] Fifty-six fine water mist nozzles 10 are provided on the side of the two liquid cooling pipes facing the battery cells 7. The fine water mist nozzles 10 are reasonably spaced so that the fine water mist can be evenly distributed on the surface of the battery cells 7. The number of the fine water mist nozzles 10 can be increased or decreased according to actual needs.

[0048] The first direction air inlet 8, the second direction air inlet 9 and the water mist nozzle 10 are all provided with valves.

[0049] The surface of the liquid cooling structure housing 1 is provided with temperature and smoke sensors for monitoring temperature changes and smoke.

[0050] When the temperature and smoke sensors detect an abnormal situation, which means that the battery temperature is too high or has caught fire, the temperature sensor detects an excessively high temperature or the smoke sensor detects smoke, the valves of the first direction air inlet 8 and the second direction air inlet 9 are opened, and the water pump power is increased at the same time. The flow rate of the cooling medium in the liquid cooling pipe reaches the requirement for extinguishing the fire, the valve of the fine water mist nozzle 10 is opened, and the air pump allows high-pressure gas to enter from the first direction air inlet 8 and the second direction air inlet 9, and the cooling medium is sprayed out through the fine water mist nozzle 10 to form fine water mist for cooling and extinguishing the fire. The cooling medium uses a non-flammable liquid, which includes but is not limited to water.

[0051] like Figure 4 As shown, the water mist nozzle 10 adopts a four-directional nozzle, and compared with the commonly used water mist nozzle, the diameter is small, and it can be installed on the surface of the liquid cooling pipe through reasonable design. The water mist nozzle 10 is seamlessly connected to the liquid cooling pipe, and the thickness is small, and the heat dissipation effect on the liquid cooling plate heat exchanger 2 can be ignored. The water mist nozzle 10 is not completely fitted with the battery unit 7, and a gap is left for the water mist nozzle 10 to spray the cooling medium.

[0052] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the implementation methods of the present invention, and should be understood that the protection scope of the present invention is not limited to such special statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. A counter-flow liquid-cooled battery management and fire extinguishing system for lithium-ion batteries, characterized in that: include: A liquid cooling structure housing (1), a liquid cooling plate heat exchanger (2) and a battery unit (7); The number of battery cells (7) is one or more, and if there are multiple battery cells, they are arranged in sequence in the same direction; A liquid cooling plate heat exchanger (2) is installed on the upper and lower surfaces of the battery unit (7); the liquid cooling structure shell (1) wraps the battery unit (7) and the liquid cooling plate heat exchanger (2); the liquid cooling structure shell (1) is fitted with the liquid cooling plate heat exchanger (2); The liquid cooling plate heat exchanger (2) comprises: two liquid cooling pipes, a water pump, an air pump, a first direction inlet pipe (3), a first direction outlet pipe (4), a second direction inlet pipe (5), a second direction outlet pipe (6), a first direction air inlet (8), a second direction air inlet (9), and a fine water mist nozzle (10); Two liquid cooling pipes are arranged side by side in an "S" shape and cover the surface of the battery unit (7); two ends of one liquid cooling pipe are respectively connected to a first direction inlet pipe (3) and a first direction outlet pipe (4); two ends of the other liquid cooling pipe are respectively connected to a second direction inlet pipe (5) and a second direction outlet pipe (6); the first direction inlet pipe (3) and the second direction outlet pipe (6) are placed in parallel and in the same direction; and the first direction outlet pipe (4) and the second direction inlet pipe (5) are placed in parallel and in the same direction; The side of the first direction inlet pipe (3) is connected to the first direction air inlet (8), and the side of the second direction inlet pipe (5) is connected to the second direction air inlet (9); The first direction inlet pipe (3) and the second direction inlet pipe (5) are connected to a water pump, and the first direction air inlet (8) and the second direction air inlet (9) are connected to an air pump; A plurality of fine water mist nozzles (10) are provided on one side of the two liquid cooling pipes facing the battery unit (7). The fine water mist nozzles (10) are reasonably spaced so that the fine water mist can be evenly distributed on the surface of the battery unit (7). The number of the fine water mist nozzles (10) is increased or decreased according to actual needs. The fine water mist nozzles (10) are not completely fitted to the battery unit (7), and a space is left for the fine water mist nozzles (10) to spray cooling medium. The first direction air inlet (8), the second direction air inlet (9) and the water mist nozzle (10) are all provided with valves; Temperature and smoke sensors are attached to the surface of the liquid cooling structure housing (1) and the battery unit (7) to monitor temperature changes and smoke; When the temperature and smoke sensors detect an abnormal situation, which means that the battery temperature is too high or has caught fire, the temperature sensor detects an excessively high temperature or the smoke sensor detects smoke, the valves of the first direction air inlet (8) and the second direction air inlet (9) are opened, and at the same time the water pump power is increased, the flow rate of the cooling medium in the liquid cooling pipe reaches the requirement for extinguishing the fire, the valve of the fine water mist nozzle (10) is opened, and the air pump allows high-pressure gas to enter through the first direction air inlet (8) and the second direction air inlet (9), and the cooling medium is sprayed out through the fine water mist nozzle (10) to form fine water mist for cooling and extinguishing the fire; the cooling medium uses a non-flammable liquid, and the non-flammable liquid includes water.

2. A counter-flow liquid-cooled battery management and fire extinguishing system for lithium-ion batteries according to claim (1), characterized in that: The water mist nozzle (10) adopts a four-directional nozzle.

3. A counter-flow liquid-cooled battery management and fire extinguishing system for lithium-ion batteries according to claim (1), characterized in that: The liquid cooling structure casing (1) is made of flame retardant material.

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