Filtering device of immersed silicone oil cooling liquid for lithium battery and use method of filtering device

Abstract

The invention belongs to the technical field of immersed cooling liquid production, and relates to a filter device for immersed cooling liquid production and a use method, in particular to a filter device suitable for production of immersed cooling liquid products with high dielectric strength requirements. In the cooling liquid filtering process, the device can form a closed space to isolate air and reduce the mixing of water vapor and dust, so that the dielectric strength and the purity loss are reduced; moreover, the pressure difference is formed by the filtering device, so that filtrate separation and outflow can be accelerated, and the filtering efficiency is further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of immersion type coolant production filtration, and relates to a filtration device for producing coolant with high dielectric strength requirements. Background Art

[0002] With the widespread application of immersion silicone oil coolant technology in energy storage systems, new energy vehicles, data centers and other fields, higher and higher requirements are placed on the performance indicators of coolants. Among them, the dielectric strength of coolants needs to be controlled at a lower level to meet the needs of safe and stable operation of equipment in these fields. However, in the current industry, the traditional coolant filtration device is still a filter press filtration device, which separates the solid and liquid in the suspension by applying pressure, and transports the suspension to the main body of the filter press by a high-pressure feed pump. The suspension enters the filter chamber under pressure, and the liquid passes through the filter cloth and is discharged through the guide groove, while the solid is intercepted to form a filter cake, such as CN2 01320559458.1, CN201320559234.0, CN202310999152.6, etc. all use filter press filtration to filter and remove impurities from the coolant. Similar filtering devices have a significant defect. During filtration, the coolant will directly contact the air and absorb moisture in the air, which reduces the dielectric strength. At the same time, impurities such as dust may also be mixed in, resulting in a decrease in its purity, affecting the operating safety and service life of the equipment. Therefore, this type of filtering equipment is suitable for coolant products with low requirements for dielectric strength and purity. However, it is difficult to meet the application fields with strict requirements for the dielectric strength and purity of the product.

[0003] In summary, there is a need to develop a filtering device suitable for the production of immersion silicone oil coolants. When filtering the coolant, it can avoid contact with the air as much as possible, thereby reducing the inhalation of water vapor and obtaining a coolant product that meets the dielectric strength performance requirements. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art and provide:

[0005] An immersion type silicone oil coolant filtering device, such as Figure 1-2 As shown:

[0006] It includes a filtration tank 2; the filtration tank 2 includes a housing body, inside which there are a mixed material chamber, a filter sheet, and a filtrate chamber 221. The mixed material chamber and the filtrate chamber 221 are oppositely arranged on both sides of the filter sheet. The housing body is used to isolate the external environment. When filtering the coolant, it can isolate the entry of external air and prevent the coolant from mixing with water vapor, dust, etc. Specifically, the number of the filtration tanks 2 can be adjusted according to production requirements. Specifically, the filter sheet is a commonly used filter sheet for filtering impurities in the coolant, such as filter paper, filter cloth, filter mesh, etc. The material, shape, size, number of layers, etc. of the filter sheet can be adjusted according to requirements; preferably, the filter sheet is filter cloth or filter paper, which can perform finer filtration with a smaller mesh number. During filtration, the mixed material chamber is filled with a mixed material of coolant, and the filter sheet is used to intercept particulate impurities. Finally, the filter residue will remain in the mixed material chamber, and the filtrate will enter the filtrate chamber 221;

[0007] The filtration device further includes a vacuum pump 31. The filtration tank 2 is also provided with a liquid outlet at the bottom of the filtrate chamber 221. The liquid outlet is not only used for vacuum pumping but also for discharging the filtrate. The liquid outlet connects the vacuum pump 31 and the filtrate chamber 221;

[0008] The filtration device further includes a liquid storage tank 3 connected between the filtration tank 2 and the vacuum pump 31. The filtrate chamber 221 of the filtration tank 2 is sequentially connected to the liquid storage tank 3 and the vacuum pump 31 via the liquid outlet. By using vacuum pumping, the air inside the filtration device can be evacuated in advance to prevent the coolant from inhaling water vapor;

[0009] The filtration device further includes a one-way filtrate pipeline 21. The front end of the one-way filtrate pipeline 21 is connected to the liquid outlet of the filtration tank 2, and the end is connected to the liquid storage tank 3. The position of the front end of the one-way filtrate pipeline 21 is higher than the end in the horizontal direction to prevent the filtrate from flowing back. When the number of filtration tanks 2 is two or more, corresponding one-way filtrate pipelines 21 are respectively configured, and each filtrate tank 2 is connected to the liquid storage tank 3 in parallel through the corresponding one-way filtrate pipeline 21. During the filtration process, by using the vacuum pumping of the vacuum pump 31 in cooperation with the one-way filtrate pipeline 21, a pressure difference is formed between the mixed material chamber and the filtrate chamber 221. The filtrate chamber 221 is in a negative pressure relative to the mixed material chamber, which makes the filtrate chamber 221 form a suction force on the mixed material to accelerate the separation of the filtrate; and, a pressure difference is formed between the liquid storage tank 3 and the filtrate chamber 221 of the filtration tank 2. The liquid storage tank 3 is in a negative pressure relative to the filtrate chamber 221, which makes the liquid storage tank 3 form a suction force on the filtrate to accelerate the flow of the filtrate.

[0010] Further, as Figure 1 shown:

[0011] The liquid storage tank 3 is provided with upper and lower cavities. The upper cavity is a vacuum cavity, and the lower cavity is a liquid storage cavity for storing liquids;

[0012] The liquid storage tank 3 is provided with a liquid inlet on the side that communicates with the end of the one-way filtrate pipeline 21, and an air extraction port that communicates with the vacuum pump 31 is also provided at the top of the vacuum chamber. The position of the liquid inlet is higher than the liquid storage chamber and lower than the air extraction port in the horizontal direction, which enables the vacuum chamber to remain connected to the liquid inlet during the filtration process, and the vacuum pump 31 can continuously evacuate the one-way filtrate pipeline 21 and the filtration tank 2;

[0013] Furthermore, the filtration device further includes:

[0014] The one-way filtrate pipeline 21 is also provided with a valve 211, and the valve 211 is used to open or close the connection between the vacuum pump 31, the liquid storage tank 3 and the filtration tank 2.

[0015] Furthermore, as Figure 4 shown:

[0016] The filtration device further includes an adsorption tank 1, and the adsorption tank 1 includes a tank body and a stirring mechanism, which are used to mix the mixed material with the adsorption material; adsorb impurities such as ammonia gas and organic pigments therein, and by uniformly mixing the adsorption material, it helps to increase the adsorption contact area and improve the adsorption effect;

[0017] The filtration tank 2 is also provided with a feed port, and the feed port is arranged at the top of the mixed material chamber. The adsorption tank 1 is connected to the feed port of the filtration tank 2, and is used to put the mixed material mixed with the adsorption material in the adsorption tank 1 into the filtration tank 2.

[0018] Furthermore, as Figure 2-3 shown:

[0019] The filtration tank 2 is of an upper and lower split structure. The mixed material chamber is arranged in the upper part, and the filtrate chamber 221 is arranged in the lower part. The filter sheet is detachably installed on the lower part, which is convenient for disassembling the filtration tank 2 for cleaning and maintenance;

[0020] A sealing structure is also arranged between the upper part and the lower part 22. The sealing structure includes a groove arranged on the surface of the lower part 22, a sealing ring 23 installed in the groove, an upper part housing that presses the sealing ring 23 and inserts into the groove, and a clamping member that fixes the upper part and the lower part, so that the outer shell of the filtration tank 2 can still isolate the external environment even after being split;

[0021] A flow channel is also arranged on the surface of the lower part 22. The flow channel is located at the outer periphery of the sealing structure and is an annular groove that depresses from the surface of the lower part 22 to the inside, and is used to block the overflow of residues after disassembly;

[0022] A support member is also arranged between the filtrate chamber 221 of the lower part 22 and the filter sheet, which is used to support the filter sheet and cooperate with it to form a stable mixed material chamber and filtrate chamber 221. The support member is arranged inside the filtrate chamber 221 and can be a bracket, such asFigure 2 As shown in the left figure, it is used to provide support at a position close to the center of the filter sheet, and the bracket can also be omitted. It is a convex platform that extends inward along the periphery of the filtrate chamber 221 of the lower split body 22 and is used to provide support at the periphery of the filter sheet. For example, Figure 2 as shown in the right figure;

[0023] A bearing sheet 241 is also arranged between the support structure and the filter sheet. As Figure 3 shown, it is used to cooperate with the bracket to provide overall support on the bottom surface of the filter sheet; the material is metal, preferably stainless steel; the bearing sheet 241 is provided with channels and convex platforms, which are alternately distributed. Specifically, they are alternately distributed radially outward relative to the center position of the bearing sheet 241. The channels are used for filtrate circulation, and the convex platforms are used to support the filter sheet. The distribution quantity, size, etc. of the channels and convex platforms can be adjusted according to actual needs.

[0024] A method for using the above-mentioned filtering device for immersion silicone oil coolant:

[0025] Using the filtering device to filter the mixed material during the production process of silicone oil coolant, including the steps:

[0026] First, turn on the vacuum pump 31, and use the vacuum pump 31 to evacuate the liquid storage tank 3 to form a vacuum tight space; and, feed the mixed material into the filtering tank;

[0027] Second, use the vacuum pump 31 to evacuate the liquid storage tank 3, the one-way filtrate pipeline 21 and the filtrate chamber of the filtering tank 2 to form a negative pressure relative to the mixed material chamber of the filtering tank 2, accelerate the separation of the filtrate from the mixed material in the filtering tank, and accelerate the storage of the filtrate in the filtrate chamber flowing into the liquid storage chamber of the liquid storage tank 3 through the one-way filtrate pipeline 21;

[0028] Third, turn off the vacuum pump.

[0029] Furthermore, before the first step, it also includes: using the adsorption tank 1 to uniformly mix activated carbon adsorption material in the mixed material for adsorption.

[0030] Furthermore, using the filtering device to recycle and filter the coolant in the lithium battery system. After the immersion coolant is used in the lithium battery system for a long time, impurities will increase, the color will become darker, etc., resulting in the coolant being difficult to continue to be used normally. After the coolant is recycled and filtered and purified, it can be put back into use. The lithium battery system is in fields such as new energy electric vehicles, energy storage devices, 5G communication base stations, and high-performance computing devices that have relatively high requirements for dielectric strength and purity.

[0031] Compared with the prior art, the filtering device provided by the present invention can simultaneously achieve the adsorption and filtration of the coolant. The specific beneficial effects are as follows:

[0032] First, a sealed space is formed, which can isolate air, reduce the mixing of water vapor and dust, and further reduce the loss of dielectric strength and purity. Secondly, it is composed of multiple simple functional devices and is easy to operate. Finally, a pressure difference is formed between the mixed material and the filtrate by using a filtering device, which can accelerate the solid-liquid separation and the outflow of the filtrate. Moreover, a pressure difference can be formed between the liquid storage device and the filtering device to accelerate the flow of the filtrate, thereby improving the filtering efficiency. Brief Description of the Drawings

[0033] Figure 1 It is the first structural schematic diagram of the filtering device for the immersion-type coolant of the present invention;

[0034] Figure 2 It is the central sectional schematic diagram after the filter tank of the filtering device for the immersion-type coolant of the present invention is separated;

[0035] Figure 3 It is the structural schematic diagram of the bearing plate in the filtering device for the immersion-type coolant of the present invention;

[0036] Figure 4 It is the second structural schematic diagram of the filtering device for the immersion-type coolant of the present invention. Detailed Description of the Invention

[0037] Prepare the mixed material: Mix 1 part of dimethylsiloxane cyclic body (commercially available DMC), 1.2 parts of hexamethyldisiloxane end-capping agent, and add 0.002 parts of tetramethylammonium hydroxide catalyst. Keep the reaction temperature at 110°C and carry out the polymerization reaction for 4 h; S2, heat to remove low-boiling components, take a sample to test the dielectric strength of the mixed material, which is the dielectric strength before filtration in the examples, and record it in Table 1:

[0038] Examples

[0039] Filter the mixed material: Add activated carbon to the material and stir to mix; then, use the filtering device of the present invention to separate and filter the coolant mixed material mixed with activated carbon in the filter tank and store it in the liquid storage tank. When the filtering time reaches 55 min, take a sample from the middle layer to test the dielectric strength of the filtrate, which is the dielectric strength after filtration in the examples, and record it in Table 1.

[0040] Comparative Examples

[0041] Filter the mixed material: Add activated carbon to the material and stir to mix; then, use a traditional pressure filtration device (Dibo small pressure filter, XAMY20-40 / 630-30U, filtration area 2 square meters) for filtration. When the filtering time reaches 55 min, take a sample from the middle layer of the filtrate to detect the dielectric strength, which is the dielectric strength after filtration in the comparative examples, and record it in Table 1.

[0042] Testing Method:

[0043] 1. Dielectric strength: Refer to the standard "Test Method for Dielectric Strength of Insulating Oil" in GB / T 507-1986, and use an insulating oil dielectric strength tester for testing.

[0044] 2. Time: A metal stopwatch.

[0045] Test results:

[0046] Table 1

[0047] Item number Example Comparative example Filtration time / min 55 55 Dielectric strength before filtration / KV 35 35 Dielectric strength after filtration / KV 34 27

[0048] In the embodiment of the present invention, the dielectric strength of the coolant product is ≥30 KV, which is a suitable immersion coolant for lithium batteries. On this basis, it also has the following advantages:

[0049] Compared with the existing pressure filtration technology in the comparative example, the loss of dielectric strength before and after filtration in the embodiment is 1 kv, while that in the comparative example is 8 kv. Comparing the two, the filtration device of the present invention has a very small impact on the dielectric strength of the coolant during filtration, and the dielectric strength after filtration is still greater than 30 kv, while that in the comparative example is lower than 30 KV, not meeting the product use requirements. It can be seen that the filtration device of the present invention has a good air isolation effect and can effectively ensure that the dielectric strength is not lost during the filtration process, and is very suitable for application fields with higher requirements for dielectric strength.

Claims

1. An immersion cooling liquid filtering device, characterized in that: The filter tank (2) comprises an outer shell, a mixture chamber, a filter plate and a filtrate chamber (221) are arranged inside the outer shell, and the mixture chamber and the filtrate chamber (221) are arranged opposite to each other on both sides of the filter plate; It also includes a vacuum pump (31); the filter tank (2) is also provided with a liquid outlet at the bottom of the filtrate chamber (221), and the liquid outlet is connected to the vacuum pump (31) and the filtrate chamber (221); It also includes a liquid storage tank (3), the liquid storage tank (3) is connected between the filter tank (2) and the vacuum pump (31), and the filtrate chamber (221) of the filter tank (2) is connected to the liquid storage tank (3) and the vacuum pump (31) in sequence via the liquid outlet; It also comprises a one-way filtrate pipeline (21), the front end of which is connected to the liquid outlet of the filter tank (2) and the rear end of which is connected to the liquid storage tank (3), and the front end of the one-way filtrate pipeline (21) is located higher than the rear end in the horizontal direction.

2. The immersion cooling liquid filtering device according to claim 1, characterized in that: The liquid storage tank (3) is provided with an upper cavity and a lower cavity, the upper cavity is a vacuum cavity, and the lower cavity is a liquid storage cavity.

3. The immersion cooling liquid filtering device according to claim 2, characterized in that: The liquid storage tank 3 is also provided with a liquid inlet on the side thereof connected to the end of the one-way filtrate pipe (21), and a vacuum port connected to the vacuum pump 31 is also provided on the top of the vacuum chamber. The position of the liquid inlet is higher than the liquid storage chamber and lower than the vacuum port in the horizontal direction.

4. The immersion cooling liquid filtering device according to claim 1, characterized in that: The filtering device also includes an adsorption tank (1), wherein the mixed material is mixed with activated carbon adsorption material; the filtering tank (2) is also provided with a feed inlet at the top of the mixed material chamber, and the adsorption tank (1) is connected to the feed inlet of the filtering tank (2).

5. The immersion cooling liquid filtering device according to claim 1, characterized in that: The filtering device further comprises a valve (211), which is arranged on the one-way filtrate pipeline (21) and is used to open or close the communication between the vacuum pump (31), the liquid storage tank (3) and the filtering tank (2).

6. The immersion cooling liquid filtering device according to claim 1, characterized in that: The filter tank (2) is an upper and lower split structure, the mixing material chamber is arranged in the upper split body, the filtrate chamber (221) is arranged in the lower split body, and the filter plate is detachably mounted on the lower split body; a sealing structure is also arranged between the upper split body and the lower split body (22); the sealing structure comprises a groove arranged on the surface of the lower split body (22), a sealing ring (23) installed in the groove, an upper split body shell that presses the sealing ring (23) and is inserted into the groove, and a clamping component that fixes the upper split body and the lower split body.

7. The immersion cooling liquid filtering device according to claim 6, characterized in that: The surface of the lower body (22) is also provided with a flow channel, which is located at the outer periphery of the sealing structure and is an annular groove that is recessed from the surface of the lower body (22) toward the inside.

8. The immersion cooling liquid filtering device according to claim 6, characterized in that: A supporting member is also provided between the filtrate cavity (221) of the lower body (22) and the filter plate, and the supporting member is provided in the filtrate cavity (221); a bearing plate (241) is also provided between the supporting member and the filter plate; the bearing plate (241) is provided with channels and bosses, and the channels and bosses are alternately distributed.

9. A method for using the immersion coolant filter device as claimed in claim 1, wherein the filter device is used to filter a mixed material during the production process of silicone oil coolant, characterized in that: Includes steps: First, the vacuum pump (31) is turned on to evacuate the liquid storage tank (3) to form a vacuum-tight space; and the mixed material is sent to the filter tank; Second, a vacuum pump (31) is used to draw a vacuum in the liquid storage tank (3), the one-way filtrate pipe (21) and the filtrate chamber of the filter tank (2) to form a negative pressure relative to the mixed material chamber of the filter tank (2), thereby accelerating the separation of filtrate from the mixed material by the filter tank, and accelerating the filtrate in the filtrate chamber to flow into the liquid storage chamber of the liquid storage tank (3) through the one-way filtrate pipe (21) for storage; Third, turn off the vacuum pump (31).

10. The immersion cooling liquid filtering device according to claim 9, characterized in that: The filtering device is used to recover filtered coolant in a lithium battery system.

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