Battery cooling liquid, preparation method thereof and liquid cooling pipeline with fire-fighting function

Abstract

The invention relates to the technical field of battery thermal management, in particular to a battery cooling liquid, a preparation method thereof and a liquid cooling pipeline with a fire-fighting function. According to the battery cooling liquid, the volume ratio of an aqueous solution of bicarbonate to ethylene glycol is 1: 1, the mass of bicarbonate in every 100g of water is 4-6g, and bicarbonate is selected from at least one of sodium bicarbonate and potassium bicarbonate. The preparation method comprises the following steps: under a closed condition of 10 DEG C, firstly adding bicarbonate into water, fully stirring, filtering a precipitate, mixing with ethylene glycol, fully stirring, filtering the precipitate again, and sealing and storing at 10-30 DEG C. The invention discloses a liquid cooling pipeline with a fire-fighting function. The liquid cooling pipeline comprises a liquid cooling main pipeline, a liquid cooling branch pipeline and cooling liquid, the cooling liquid provided by the invention not only has small corrosion to the liquid cooling pipeline, but also can act together with aluminum sulfate designed on the liquid cooling branch pipeline to play a fire extinguishing function, and a fire extinguishing system does not need to be arranged in the battery pack, so that the cost is low, and the production efficiency is high.

Description

Technical Field

[0001] The present invention relates to the technical field of battery thermal management, and in particular to a battery coolant, a preparation method thereof, and a liquid cooling pipeline with fire-fighting function. Background Art

[0002] The design of the cooling system and fire protection system of new energy batteries is a key link to ensure their safe and efficient operation. The core goal of its cooling system is to maintain the battery pack within a suitable operating temperature range to improve battery performance, extend battery life and reduce the risk of thermal runaway. For example, the liquid cooling system uses liquid cooling pipes and pumps to circulate coolant and dissipate heat through liquid cooling plates close to battery cells. The core goal of its fire protection system is to respond quickly when thermal runaway or fire occurs in the battery, control the spread of fire, and protect the safety of personnel and property.

[0003] In the prior art, the cooling system and the fire protection system are generally designed independently of each other, such as Figure 4 and Figure 5 As shown in common: the fire protection system is designed at the top of the entire system and is connected to each battery pack. Each battery pack is equipped with a fire detection device and a fire extinguishing agent spraying device. When the fire detection device detects a fire in the battery pack, the fire extinguishing agent spraying device will be turned on to spray the fire extinguishing agent to extinguish the fire; the liquid cooling host is set at the bottom of the entire system and is connected to the liquid cooling pipe of each battery pack. The coolant such as a water-ethylene glycol mixture with a volume ratio of 1:1 is pumped to the liquid cooling pipe to maintain the battery pack within a suitable operating temperature range. The separate design of the cooling system and the fire protection system results in serious waste of space for new energy batteries and numerous pipeline connections, which is not conducive to improving the energy density of the battery, and may also lead to frequent abnormal situations such as disconnection of the pipeline due to collision. In addition, the manufacturing process is cumbersome, the manufacturing cost is high, and the manufacturing efficiency is low.

[0004] In addition, the common coolant composition is a mixture of water and ethylene glycol in a volume ratio of 1:1. After long-term use, ethylene glycol may be partially oxidized to form oxalic acid, which will cause corrosion and damage to the liquid cooling pipes, affecting the service life of the liquid cooling pipes. Therefore, the coolant needs to be replaced in time. Regular replacement of the coolant invisibly increases the cost of battery use.

[0005] To this end, the present invention is proposed. Summary of the invention

[0006] In view of the above-mentioned shortcomings of the prior art, the present invention provides a battery coolant, a preparation method thereof and a liquid cooling pipeline with fire-fighting function.

[0007] First, the present invention proposes a battery coolant, which is prepared by mixing an aqueous solution of bicarbonate and ethylene glycol in a volume ratio of 1:1. The aqueous solution of bicarbonate is obtained by dissolving bicarbonate in water. The mass of bicarbonate in every 100g of water is 4-6g, and the bicarbonate is selected from at least one of sodium bicarbonate and potassium bicarbonate.

[0008] Secondly, the present invention proposes a method for preparing the above-mentioned battery coolant: under a closed condition at 10°C, first add bicarbonate into water and stir it thoroughly, filter the precipitate to obtain a bicarbonate aqueous solution, then mix the bicarbonate aqueous solution with ethylene glycol and stir it thoroughly, filter the precipitate again and store it in a sealed state at 10-30°C.

[0009] Thirdly, the present invention proposes a liquid cooling pipeline with fire-fighting function, including: a liquid cooling main pipeline, a liquid cooling branch pipeline and a coolant.

[0010] Furthermore, it also includes: a fire detector, a solenoid valve, a material storage tube and a nozzle located in each battery pack. The solenoid valve and the material storage tube are successively installed on the liquid cooling branch pipe. One end of the liquid cooling branch pipe is connected to the liquid cooling main pipe, and the other end is used to install the nozzle. The fire detector is installed in each battery pack and connected to the solenoid valve. Aluminum sulfate powder is contained in the material storage tube, and the aluminum sulfate powder is connected to the liquid cooling branch pipe through a water-soluble film.

[0011] Furthermore, the storage tube is a hollow cylindrical structure with both ends closed, consisting of an outer tube and an inner tube. Aluminum sulfate powder is placed in a containing cavity formed by the outer tube and the inner tube. A plurality of feed holes are provided on the tube wall of the inner tube, and the feed holes are coated with a water-soluble film.

[0012] Furthermore, the pipe pressure of the liquid cooling branch pipe is 2 bar, and the feed hole is a circular hole with a diameter of 0.1-5 mm.

[0013] Furthermore, the water-soluble film is a water-soluble PVA film.

[0014] Furthermore, a filling hole is opened on the end surface of the outer tube, and a packaging plate is arranged outside the filling hole.

[0015] Furthermore, the material storage tube is made of metal, the outer diameter of the outer tube is 5 cm, the inner diameter of the inner tube is 1 cm, and the wall thickness of the outer tube and the inner tube is 1 mm.

[0016] Furthermore, both ends of the inner pipe are connected to the liquid cooling branch pipe by welding or gluing.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects:

[0018] (1) By adding bicarbonate to conventional water-ethylene glycol coolant, the acidity of the coolant is reduced and the pH value is increased, which can effectively reduce the corrosion of the coolant on the metal parts of the entire liquid cooling pipeline, help extend the service life of the liquid cooling pipeline, extend the coolant replacement cycle, and reduce the frequency of coolant replacement.

[0019] (2) By arranging a storage pipe filled with aluminum sulfate powder on the liquid cooling branch pipe, when a fire occurs, the coolant flows out and reacts chemically with the aluminum sulfate to generate a foam liquid with good fire extinguishing effect, thereby eliminating the traditional fire fighting system, saving space and cost, and simplifying the manufacturing process of the entire battery system, thereby improving the production efficiency of the entire battery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 This is a schematic diagram of the structure of the liquid cooling pipeline with fire-fighting function proposed by the present invention;

[0022] Figure 2 for Figure 1 Partial schematic Figure 1 ;

[0023] Figure 3 for Figure 1 Partial schematic Figure 2 ;

[0024] Figure 4 is prior art;

[0025] Figure 5 for Figure 4 Schematic diagram of the fire protection system.

[0026] Among them: 1. Liquid cooling main pipeline; 2. Fire detector; 3. Solenoid valve; 4. Storage pipe; 5. Nozzle; 6. Aluminum sulfate powder; 7. Liquid cooling branch pipeline; 8. Inner pipe; 9. Filling hole; 10. Packaging plate. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0028] The raw materials used in the following examples and comparative examples were all commercially available. The operations not described in detail in the following examples and comparative examples are all conventional techniques in the art.

[0029] On the one hand, the present invention proposes a battery coolant, which is prepared by mixing an aqueous solution of bicarbonate and ethylene glycol in a volume ratio of 1:1, wherein the aqueous solution of bicarbonate is obtained by dissolving bicarbonate in water, and the mass of bicarbonate in every 100g of water is 4-6g.

[0030] On the other hand, the present invention proposes a method for preparing a battery coolant. Under closed conditions at 10°C, bicarbonate is first added to water and fully stirred. After filtering the precipitate, a bicarbonate aqueous solution is obtained. The bicarbonate aqueous solution is then mixed with ethylene glycol and fully stirred. After filtering the precipitate again, the coolant is sealed and stored at 10-30°C.

[0031] In addition, the present invention also proposes a liquid cooling pipeline with fire-fighting function, including: a liquid cooling main pipeline 1, a liquid cooling branch pipeline 7 and the above-mentioned coolant.

[0032] As a preferred technical solution, another embodiment of the present invention further includes: a fire detector 2, a solenoid valve 3, a storage tube 4 and a nozzle 5 located in each battery pack. The solenoid valve 3 and the storage tube 4 are successively installed on the liquid cooling branch pipe 7. One end of the liquid cooling branch pipe 7 is connected to the liquid cooling main pipe 1, and the other end is used to install the nozzle 5. The fire detector 2 is installed in each battery pack and connected to the solenoid valve 3. Aluminum sulfate powder 6 is contained in the storage tube 4, and the aluminum sulfate powder 6 is connected to the liquid cooling branch pipe 7 through a water-soluble film.

[0033] When the fire detector 2 detects a fire in the battery pack, it will issue a command to open the solenoid valve 3 to allow the coolant to be released. After the coolant is released, the water-soluble film melts when it flows through the storage tube 4, prompting the aluminum sulfate powder 6 to dissolve. The bicarbonate in the coolant reacts chemically with the aluminum sulfate powder 6 to generate aluminum hydroxide and carbon dioxide. Taking sodium bicarbonate as an example, the chemical reaction equation is: Al2(SO4)3+6NaHCO3=3Na2SO4+2Al(OH)3↓+6CO2↑. The carbon dioxide generated by the reaction forms a foam with carbon dioxide as the core and aluminum hydroxide wrapped on the outside. The foam has the characteristics of strong burning resistance, good durability, good viscosity, etc., and has a good covering effect and cooling effect. On the other hand, it exerts a pressurizing effect to make the foam spray out, and finally makes the foam spray out quickly from the nozzle 5 and adhere to the surface of the burning object, effectively reducing the temperature of the burning object and isolating it from oxygen, and playing an excellent fire extinguishing effect.

[0034] When the fire detector 2 detects that the fire in the battery pack is extinguished, it will issue a command to close the solenoid valve 3, not allowing the coolant to pass through, thereby stopping the release of the coolant.

[0035] It should be noted that the components not described in detail, such as the fire detector 2, the solenoid valve 3, the nozzle 5, etc., are all existing technologies.

[0036] The fire detector 2 can be specifically: Qianye Technology TC01-LN-CYW-QY energy storage fire three-in-one fire detector, which can detect carbon monoxide, temperature, and smoke to determine whether a fire has occurred; Qianye Technology TC01B-QY composite fire detector, which can detect carbon monoxide, hydrogen, temperature, smoke, and VOC gas concentration (to determine whether the electrolyte has leaked). Of course, other fire detectors with similar functions can also be used. In theory, any conventional fire detector with carbon monoxide, temperature, and smoke detection functions can be used in the present invention.

[0037] Nozzle 5 is preferably a porous foam nozzle, which can be a horizontal porous foam nozzle installed on the side of the battery pack to spray foam horizontally from the side, or a top spray porous foam nozzle installed on the upper part of the battery pack to spray foam from top to bottom to cover the entire top area of ​​the battery pack, or a catapult porous foam nozzle installed on the lower part of the battery pack to spray foam in both vertical and horizontal directions to cover the bottom and sides of the battery pack.

[0038] As a preferred technical solution, in another embodiment of the present invention, the storage tube 4 is a hollow cylindrical structure with closed ends composed of an outer tube and an inner tube 8, and the aluminum sulfate powder 6 is placed in the accommodating cavity formed by the outer tube and the inner tube 8, and a plurality of feed holes are provided on the tube wall of the inner tube, and the feed holes are coated with a water-soluble film.

[0039] In this embodiment, the water-soluble film is a prior art film, preferably a water-soluble film that can be quickly dissolved within 5 seconds, and blocks the feed hole when the coolant does not flow through to prevent the aluminum sulfate powder 6 from leaking.

[0040] In this embodiment, the specific method of coating the feed hole with a water-soluble film can be that a film unit with a size larger than the feed hole is cut and adhered to the feed hole to coat it, or the water-soluble film is entirely coated on the outer surface or inner surface of the inner tube 8. Considering the feasibility of the coating operation, the coating efficiency and the fire extinguishing effect, it is preferred to use a water-soluble film to entirely coat the inner surface of the inner tube 8, for example, the water-soluble film is adhered to the entire inner surface of the inner tube 8 by glue.

[0041] In this embodiment, when the coolant flows through the inner tube 8, the water-soluble film dissolves rapidly under the action of the water in the coolant, and the aluminum sulfate powder 6 near the feed hole partially dissolves and slowly and continuously enters the inner tube 8 through the feed hole and reacts with the bicarbonate in the coolant to generate foam with fire extinguishing function.

[0042] As a preferred technical solution, in another embodiment of the present invention, the pipe pressure of the liquid cooling branch pipe 7 is 2 bar, and the feed hole is a round hole with a diameter of 0.1-5 mm. For example, the diameter of the round hole can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2. 0mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3.0mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5m m, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4.0mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm, 4.9mm, 5.0mm.

[0043] In this embodiment, under the premise that the pipe pressure of the liquid cooling branch pipe 7 is limited to 2 bar and the diameter of the circular hole is 0.1-5 mm, the particle size of the aluminum sulfate powder 6 should not be too large or too small. Too large a particle size will lead to too small a specific surface area, and too small a particle size will lead to too large a specific surface area. After the water-soluble film is dissolved, if the specific surface area of ​​the aluminum sulfate powder 6 is too small, its contact area with water is small, the dissolution rate is too slow, the amount of aluminum sulfate entering the inner tube 8 is too small, the generated foam is too thin, the viscosity is poor, the covering effect and cooling effect are not good, and the fire extinguishing function cannot be played well; if the specific surface area of ​​the aluminum sulfate powder 6 is too large, its contact area with water is large, the dissolution rate is too fast, the amount of aluminum sulfate entering the inner tube 8 is too much, and the generated foam is too thick. Although the covering effect and cooling effect are good, the too thick causes the resistance of its spraying to be large, so that the foam cannot be sprayed quickly, smoothly, and continuously, and therefore the fire extinguishing function cannot be played well.

[0044] The present invention has been proved through creative labor that: when the particle size of aluminum sulfate powder 6 is 0.3-3.0 mm, the amount of aluminum sulfate powder 6 that dissolves into the inner tube 8 through the circular discharge hole with a diameter of 0.1-5 mm is appropriate, the generated foam has moderate consistency, and can be smoothly sprayed out and quickly covered on the surface of the burning object under the tube pressure of 2 bar and the pressurization of carbon dioxide to play the role of cooling and isolating oxygen, and the fire extinguishing effect is good. Among them, when the diameter of the discharge hole is 0.5 mm and the particle size of aluminum sulfate powder 6 is 2.0 mm, the fire extinguishing effect is particularly good.

[0045] As a preferred technical solution, in another embodiment of the present invention, the water-soluble film is a water-soluble PVA film.

[0046] The water-soluble PVA film has good biodegradability. All of its components are C, H, and O compounds. They can be decomposed by microorganisms in the natural environment and eventually converted into carbon dioxide and water. They will not pollute the environment and have excellent environmental performance.

[0047] In this embodiment, the water-soluble PVA film is a prior art, for example, the water-soluble PVA film produced by Shenzhen Fujin Spinning Adhesive Film Co., Ltd. can be used, which can be dissolved within 5 seconds and quickly open the feeding hole. Moreover, the water-soluble PVA film will form a glue liquid after dissolving in water, which helps to increase the viscosity and durability of the foam, and will not have an adverse effect on the smooth spraying of the foam, and make the foam have a good covering effect. It synergizes and interacts with the foam with carbon dioxide as the core and aluminum hydroxide wrapped on the outside, and plays a good fire extinguishing role.

[0048] As a preferred technical solution, in another embodiment of the present invention, a filling hole 9 is opened on the end surface of the outer tube, and a packaging plate 10 is arranged outside the filling hole 9.

[0049] In this embodiment, aluminum sulfate powder 6 can be added to the storage tube 4 through the filling hole 9, and the packaging plate 10 arranged outside it is disassembled when replenishing and installed after replenishing to ensure that the storage tube 4 is in a sealed state. The structure of the filling hole 9 is not limited, and it can be a regular hole structure such as a circular hole, a square hole, or an irregular hole structure. The structure of the packaging plate 10 is not limited, as long as it can fully cover the filling hole 9, the packaging plate 10 is detachably connected to the end face of the outer tube, and the specific method of detachable connection is not required, and any existing technology that can achieve detachable connection can be used, such as screw connection.

[0050] In this embodiment, the storage tube 4 does not contain aluminum sulfate powder 6 at the beginning. After the empty storage tube 4 is connected to the liquid cooling branch pipe 7, the aluminum sulfate powder 6 is filled in through the filling hole 9. The aluminum sulfate powder 6 does not undergo any compaction operation and is a dry aluminum sulfate powder that meets the particle size requirements and has good fluidity. This embodiment is convenient for the connection operation between the storage tube 4 and the liquid cooling branch pipe 7, and the aluminum sulfate powder 6 will not leak due to premature rupture of the water-soluble film caused by external force, and has good practicality.

[0051] As a preferred technical solution, in another embodiment of the present invention, the material storage tube 4 is made of metal, the outer diameter of the outer tube is 5 cm, the inner diameter of the inner tube 8 is 1 cm, and the wall thickness of the outer tube and the inner tube 8 is 1 mm.

[0052] In this embodiment, the material storage pipe 4 is made of metal, preferably three-series aluminum or Q235 steel, and preferably has a thickness of 1 mm. The liquid cooling branch pipe 7 and the liquid cooling main pipe 1 can be made of the same material as the material storage pipe 4, or different materials.

[0053] In this embodiment, the inner diameter of the inner tube 8 is mainly to adapt to the existing liquid cooling branch pipe 7 setting. The conventional inner diameter of the liquid cooling branch pipe 7 is 1 cm. The two ends of the inner tube 8 are respectively connected to the two sections of the liquid cooling branch pipe 7 and the connecting surfaces are fixed by welding.

[0054] As a preferred technical solution, in another embodiment of the present invention, both ends of the inner tube 8 are connected to the liquid cooling branch pipe 7 by welding or gluing. After the solenoid valve 3 is opened, the coolant enters the inner tube 8 through the liquid cooling branch pipe 7 at one end, and then flows out from the liquid cooling branch pipe 7 at the other end. During the flow in the inner tube 8, the coolant mixes with the aluminum sulfate 6 and undergoes a chemical reaction.

[0055] In summary: the present invention reduces the acidity of the coolant by adding bicarbonate to the conventional water-ethylene glycol coolant, effectively reduces the corrosion of the coolant to the metal parts of the entire liquid cooling pipeline, prolongs the service life of the liquid cooling pipeline, prolongs the replacement cycle of the coolant, and reduces the replacement frequency of the coolant; on this basis, by arranging a storage pipe filled with aluminum sulfate powder on the liquid cooling branch pipeline, when a fire occurs, the coolant flows out and reacts chemically with aluminum sulfate to generate foam liquid with good fire extinguishing effect, thereby eliminating the traditional fire fighting system. The liquid cooling pipeline proposed by the present invention integrates liquid cooling function and fire fighting function, which saves space and cost, simplifies the manufacturing process of the entire battery system, and improves the production efficiency of the entire battery system.

[0056] Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. Those skilled in the art may change, modify, replace and deform the above embodiments within the scope of the present invention. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples without contradiction.

Claims

1. A battery coolant, characterized in that: The bicarbonate aqueous solution is mixed with ethylene glycol in a volume ratio of 1:

1. The bicarbonate aqueous solution is obtained by dissolving bicarbonate in water. The mass of bicarbonate in every 100g of water is 4-6g. The bicarbonate is selected from at least one of sodium bicarbonate and potassium bicarbonate.

2. A method for preparing a battery coolant according to claim 1, characterized in that: Under a sealed condition at 10°C, first add bicarbonate into water and stir thoroughly, filter the precipitate to obtain a bicarbonate aqueous solution, then mix the bicarbonate aqueous solution with ethylene glycol and stir thoroughly, filter the precipitate again and seal and store at 10-30°C.

3. A liquid cooling pipeline with fire-fighting function, characterized in that: include: A liquid cooling main pipeline (1), a liquid cooling branch pipeline (7), and the coolant as claimed in claim 1.

4. The liquid cooling pipeline with fire-fighting function according to claim 3 is characterized in that: The invention also includes: a fire detector (2), a solenoid valve (3), a material storage pipe (4) and a nozzle (5) located in each battery pack. The solenoid valve (3) and the material storage pipe (4) are successively installed on a liquid cooling branch pipe (7). One end of the liquid cooling branch pipe (7) is connected to the liquid cooling main pipe (1), and the other end is used to install the nozzle (5). The fire detector (2) is installed in each battery pack and connected to the solenoid valve (3). Aluminum sulfate powder (6) is contained in the material storage pipe (4), and the aluminum sulfate powder (6) is connected to the liquid cooling branch pipe (7) through a water-soluble film.

5. The liquid cooling pipeline with fire-fighting function according to claim 4 is characterized in that: The material storage tube (4) is a hollow cylindrical structure with closed ends, which is composed of an outer tube and an inner tube (8). Aluminum sulfate powder (6) is placed in a containing cavity formed by the outer tube and the inner tube (8). A plurality of material discharge holes are arranged on the tube wall of the inner tube, and the material discharge holes are coated with a water-soluble film.

6. The liquid cooling pipeline with fire-fighting function according to claim 5 is characterized in that: The pipe pressure of the liquid cooling branch pipe (7) is 2 bar, and the feed hole is a circular hole with a diameter of 0.1-5 mm.

7. The liquid cooling pipeline with fire-fighting function according to claim 5, characterized in that: The water-soluble film is a water-soluble PVA film.

8. The liquid cooling pipeline with fire-fighting function according to claim 5, characterized in that: A filling hole (9) is provided on the end surface of the outer tube, and a packaging plate (10) is arranged outside the filling hole (9).

9. The liquid cooling pipeline with fire-fighting function according to claim 5, characterized in that: The material storage tube (4) is made of metal, the outer diameter of the outer tube is 5 cm, the inner diameter of the inner tube (8) is 1 cm, and the wall thickness of the outer tube and the inner tube (8) is 1 mm.

10. The liquid cooling pipeline with fire-fighting function according to any one of claims 5 to 9, characterized in that: The two ends of the inner tube (8) are connected to the liquid cooling branch pipe (7) by welding or gluing.

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