Cooling system

Abstract

To provide a cooling system capable of highly maintaining insulation properties of insulation coolant while suppressing circulation energy loss.SOLUTION: A cooling system has a circulation path which allows non-aqueous insulation coolant to circulate, and a coolant storage part which is provided for the circulation path, and stores the insulation coolant, where the specific gravity of the insulation coolant is smaller than water, the coolant storage part has a moisture removing part inside thereof, and the moisture removing part is fixed to the coolant storage part such that at least a part of its top face directly contact the insulation coolant.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to cooling systems. [Background technology]

[0002] In cooling systems that circulate coolant to cool electrical components such as batteries, the coolant used is required to have high insulating properties. If water gets into the coolant, the water may cause problems such as short-circuiting between terminals of the electrical components or corrosion of the components. To prevent an increase in the conductivity of the coolant, for example, Patent Document 1 discloses a technology in which a filter for removing water is installed in the circulation path of a cooling system that uses a non-aqueous insulating coolant.

[0003] Furthermore, Patent Document 2 discloses a cooling device in which a moisture-removing filter is arranged to block the coolant discharge port of a coolant storage tank provided in the coolant circulation path. Patent Document 3 discloses a liquid cooling device for electric and electronic components provided with a moisture capture material that can capture moisture in the refrigerant by reacting with water. Patent Document 4 discloses a water remover in which granular water-absorbing polymer is enclosed in a wire mesh, and Patent Document 5 discloses a method of removing water dispersed in an oil phase using water-absorbing resin powder enclosed in a resin mesh bag. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-158432 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-050624 [Patent Document 3] Japanese Patent Application Publication No. 02-216855 [Patent Document 4] Japanese Patent Publication No. 2022-097321 [Patent Document 5] Japanese Patent Application Laid-Open No. 2017-104817 Summary of the Invention [Problem to be solved by the invention]

[0005] If a moisture removal unit is installed in a way that blocks the coolant circulation path, the flow resistance increases, the coolant flow rate decreases, and cooling performance decreases significantly, so it is necessary to increase the output of the pressure pump to ensure the flow rate. Also, in non-aqueous coolants such as oil, moisture often aggregates and exists as large droplets, so if a water-absorbent resin is sealed within the mesh, the water droplets may not be able to pass through the mesh and reach the water-absorbent resin.

[0006] The present disclosure has been made in consideration of the above-mentioned circumstances, and its main object is to provide a cooling system that can maintain high insulating properties of insulating coolant while suppressing circulating energy loss. [Means for solving the problem]

[0007] [1] A cooling system having a circulation path for circulating a non-aqueous insulating cooling liquid, and a cooling liquid reservoir provided in the circulation path for storing the insulating cooling liquid, wherein the insulating cooling liquid has a specific gravity lower than that of water, and the cooling liquid reservoir has a moisture removal part therein, and the moisture removal part is fixed to the cooling liquid reservoir so that at least a portion of its upper surface is in direct contact with the insulating cooling liquid.

[0008] [2] The cooling system according to [1], wherein at least a portion of the moisture removal unit is fixed to a bottom surface of the coolant reservoir unit.

[0009] [3] The cooling system according to [1] or [2], wherein the moisture removal unit contains porous zeolite or a water-absorbent resin as a moisture absorber.

[0010] [4] The cooling system according to [3], wherein the water-absorbing resin is at least one selected from the group consisting of a partially neutralized crosslinked product of polyacrylic acid, a neutralized product of a starch-acrylic acid graft polymer, a hydrolyzed product of a starch-acrylonitrile graft polymer, a saponified product of a vinyl acetate-acrylic acid ester copolymer, a crosslinked product of an isobutylene-maleic anhydride copolymer, a hydrolyzed product of an acrylonitrile copolymer or an acrylamide copolymer, or a crosslinked product thereof, a crosslinked product of an acrylate-acrylamide copolymer, a crosslinked product of a polyvinyl alcohol, a crosslinked product of a modified polyethylene oxide, a crosslinked product of an acrylamido-2-methylpropanesulfonate copolymer, a crosslinked product of a (meth)acryloylalkanesulfonate copolymer, a crosslinked carboxymethylcellulose salt, and a crosslinked polymer of a cationic monomer.

[0011] [5] The cooling system according to [3] or [4], wherein the water-absorbing resin is a crosslinked partially neutralized polyacrylic acid or a neutralized starch-acrylic acid graft polymer. [Effects of the Invention]

[0012] The cooling system according to the present disclosure has the advantage of being able to maintain high insulating properties of the insulating coolant while suppressing circulating energy loss. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic configuration diagram illustrating an example of a cooling system according to the present disclosure. [Figure 2] FIG. 2 is a schematic cross-sectional view showing an example of a coolant reservoir in the present disclosure. [Figure 3] 3 is a schematic cross-sectional view illustrating an example of a coolant reservoir in the present disclosure. FIG. [Figure 4] FIG. 10 is a schematic cross-sectional view showing another example of a coolant reservoir in the present disclosure. [Figure 5] FIG. 10 is a schematic cross-sectional view showing an example of a coolant reservoir in which a conventional moisture remover is arranged. DETAILED DESCRIPTION OF THE INVENTION

[0014] The cooling system of the present disclosure will be described in detail below.

[0015] FIG. 1 is a schematic diagram illustrating an example of a cooling system according to the present disclosure. The cooling system 100 illustrated in FIG. 1 includes a circulation path 1 for circulating a non-aqueous insulating coolant and a coolant reservoir 2 provided in the circulation path 1 for storing the insulating coolant. The flow of the insulating coolant in the circulation path 1 can be controlled by a pump 10 or the like. The cooling system 100 according to the present disclosure can be mounted on, for example, a vehicle and used to cool heat-generating devices such as an inverter 11, an oil cooler 12, and a battery 13 that are connected in series to the circulation path 1. A radiator 14 is provided in the circulation path 1 to exchange heat with outside air, thereby cooling the insulating coolant that has been heated by cooling the heat-generating devices.

[0016] 2 is a schematic cross-sectional view showing an example of a coolant reservoir according to the present disclosure. The moisture removal unit 4 is fixed to the coolant reservoir 2 so that at least a portion of its upper surface is in direct contact with the insulating cooling liquid 3. Because the specific gravity of the insulating cooling liquid 3 used in the present disclosure is smaller than that of water, moisture mixed into the insulating cooling liquid 3 sinks within the coolant reservoir 2, coagulates, and forms droplets 21, which are then absorbed by the moisture removal unit 4 (moisture absorber 5) and removed from the insulating cooling liquid 3.

[0017] In the cooling system of the present disclosure, the moisture removal part is fixed to the coolant reservoir so that at least a portion of the upper surface of the moisture removal part is in direct contact with the insulating coolant, thereby efficiently removing moisture from the insulating coolant without stagnation of the flow of the insulating coolant in the circulation path, thereby suppressing circulation energy loss and maintaining high insulating properties of the insulating coolant.

[0018] If the moisture removal unit is installed by blocking the coolant circulation path or the inlet and outlet of the coolant storage unit so that all of the coolant passes through the moisture removal unit, the flow path resistance increases, the coolant flow rate decreases, and the cooling performance is significantly reduced. Therefore, it is necessary to increase the output of the pressure pump to ensure the flow rate. On the other hand, as described above, the present disclosure uses an insulating coolant with a specific gravity lower than water, so moisture mixed into the insulating coolant sinks in the coolant storage unit and collects at the bottom of the coolant storage unit. Therefore, by arranging the moisture removal unit in the area where water droplets collect in the coolant storage unit and absorbing the moisture, it is possible to remove moisture from the insulating coolant without increasing the output of the pressure pump.

[0019] Furthermore, in non-aqueous coolants such as oil, if the moisture absorber is enclosed in a mesh bag or the like, large aggregated water droplets may not be able to pass through the mesh and may not reach the water-absorbing resin. On the other hand, in the present disclosure, the moisture removal unit is fixed to the coolant reservoir so that at least a portion of its upper surface is in direct contact with the insulating coolant, so that water droplets can be absorbed smoothly and quickly without being obstructed by a structure such as a mesh bag interposed between the moisture absorber of the moisture removal unit and the insulating coolant.

[0020] The cooling system according to the present disclosure includes a circulation path for circulating an insulating cooling liquid and a cooling liquid reservoir for storing the insulating cooling liquid. Each component of the cooling system according to the present disclosure will be described below.

[0021] 1. Insulating coolant The insulating coolant used in the present disclosure is not particularly limited as long as it is a non-aqueous, insulating liquid with a specific gravity lower than that of water. For example, mineral oil containing hydrocarbon compounds such as aromatic hydrocarbons, paraffinic hydrocarbons, and naphthenic (cycloalkane) hydrocarbons can be used.

[0022] 2. Circulation route The circulation path in the cooling system of the present disclosure is a path for circulating the insulating cooling liquid. The circulation path is not particularly limited as long as it has piping for circulating the insulating cooling liquid between the cooled body and the cooling liquid reservoir, and general piping similar to piping for circulating lubricating oil or the like can be used.

[0023] 3. Coolant reservoir The cooling liquid reservoir is provided in the circulation path and stores the insulating cooling liquid. The material, shape, size, etc. of the cooling liquid reservoir are not particularly limited as long as they can store the insulating cooling liquid therein. For example, the cooling liquid reservoir may be a rectangular or cylindrical container made of resin or metal, and the shape may be appropriately determined depending on the shape of the location where the cooling liquid reservoir is to be placed and the amount of insulating cooling liquid to be stored therein.

[0024] The type of coolant reservoir is not particularly limited, and for example, a single-mouth container such as a pressurized reserve tank for a radiator (see FIG. 3(a)) can be used. Alternatively, a two-mouth container as shown in FIG. 3(b) can be used. In the case of a two-mouth container, one mouth may be open to the atmosphere, like an open-to-air reserve tank, and insulating coolant may flow in / out from the other mouth, or it may be a circulating type in which insulating coolant flows in from one mouth and is discharged from the other mouth.

[0025] A moisture removal unit is fixed inside the coolant reservoir. The location of the moisture removal unit within the coolant reservoir is not particularly limited as long as it does not interfere with the flow of the insulating cooling liquid. The moisture removal unit can be located on the bottom or side of the coolant reservoir so as not to block the inlet and outlet of the insulating cooling liquid. In particular, it is preferable that at least a portion of the moisture removal unit is located on the bottom of the coolant reservoir. This is because it can efficiently absorb water droplets that have sunk to the bottom of the coolant reservoir due to differences in specific gravity. In this case, the moisture removal unit may be located on only a portion of the bottom of the coolant reservoir, or on the entire bottom surface.

[0026] The moisture removal unit can be fixed to the coolant reservoir by directly or indirectly fixing the moisture absorber of the moisture removal unit to the coolant reservoir. For example, if the moisture absorber of the moisture removal unit is a pellet- or block-shaped material measuring 5 mm or larger, this can be achieved by directly adhesively fixing a moisture removal unit 4 consisting only of a moisture absorber 5 to the bottom surface of the coolant reservoir 2, as shown in FIG. 2. Smaller moisture absorber pellets or blocks have a larger surface area and therefore exhibit high water absorption performance. On the other hand, larger moisture absorber pellets or blocks exhibit high adhesiveness. Therefore, the size of the moisture absorber is preferably small enough to exhibit stable adhesiveness, and can be appropriately selected depending on the properties required of the moisture removal unit.

[0027] Furthermore, when the moisture absorber is a powdered or particulate substance with a size of less than 5 mm, as exemplified in FIG. 4, the moisture absorber 5 can be dispersed and disposed within a resin piece (resin-embedded portion 6), and the resin-embedded portion 6 containing the moisture absorber 5 can be adhesively fixed to the bottom surface of the coolant reservoir 2, thereby indirectly fixing the moisture absorber 5 to the coolant reservoir 2. When the moisture removal portion has a moisture absorber and a resin-embedded portion, the moisture absorber is disposed so that at least a portion of its surface is exposed to the surface (top surface) of the resin-embedded portion. By disposing such a moisture removal portion so that it is immersed in the insulating coolant, the moisture absorber can be brought into direct contact with the insulating coolant.

[0028] Examples of the moisture absorber include porous zeolites such as molecular sieves and water-absorbing resins. Examples of the water-absorbing resin include crosslinked polyacrylic acid partially neutralized products, neutralized starch-acrylic acid graft polymers, hydrolyzed starch-acrylonitrile graft polymers, saponified vinyl acetate-acrylic acid ester copolymers, crosslinked isobutylene-maleic anhydride copolymers, hydrolyzed acrylonitrile copolymers or acrylamide copolymers or their crosslinked products, crosslinked acrylate-acrylamide copolymers, crosslinked polyvinyl alcohol, crosslinked modified polyethylene oxide, crosslinked acrylamido-2-methylpropanesulfonate copolymers, crosslinked (meth)acryloylalkanesulfonate copolymers, crosslinked carboxymethylcellulose salts, and crosslinked polymers of cationic monomers. Among these, crosslinked polyacrylic acid partially neutralized products and neutralized starch-acrylic acid graft polymers can be preferably used.

[0029] The resin used for the resin-filled portion is not particularly limited as long as it is resistant to the insulating cooling liquid, and examples thereof include thermosetting resins such as epoxy resin, polyfunctional cyanate ester resin, polyfunctional maleimide-cyanate ester resin, polyfunctional maleimide resin, unsaturated polyester resin, and unsaturated group-containing polyphenylene ether resin.

[0030] 4. Cooling system The use of the cooling system of the present disclosure is not particularly limited, and it can be used, for example, to cool batteries, inverters, oil coolers, etc. of vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), electric vehicles (BEVs), gasoline-powered vehicles, diesel-powered vehicles, etc. The cooling system of the present disclosure may also be used to cool electrical components of moving objects other than vehicles (for example, trains, ships, and aircraft), machine tools, information processing devices, etc.

[0031] The cooling system may include a pressure pump for generating a circulating flow of the insulating coolant, and a heat exchanger such as a radiator for lowering the temperature of the insulating coolant after cooling the object to be cooled. Also, the circulation path may include sensors for measuring the temperature, conductivity, moisture content, etc. of the insulating coolant, an alarm unit for notifying those around when the measured value exceeds a threshold, and a control unit for controlling these components.

[0032] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and any configuration that is substantially identical to the technical idea described in the claims of the present disclosure and that provides similar effects is included within the technical scope of the present disclosure. [Example]

[0033] [Example 1] As shown in FIG. 2, a coolant reservoir 2 having a moisture removal section 4 in which a water-absorbent resin serving as a moisture absorber 5 is adhesively fixed to the bottom surface of the coolant reservoir 2 was filled with a non-aqueous insulating coolant 3, water droplets 21 were added, and the coolant reservoir 2 was left to stand for a certain period of time.

[0034] [Example 2] As shown in FIG. 4, a moisture removal section 4 having a moisture absorber 5 (a water-absorbent resin) exposed on the top surface of a resin-filled section 6 is fixed to the bottom surface of a coolant storage section 2. The coolant storage section 2 is filled with a non-aqueous insulating coolant 3, water droplets 21 are added, and the coolant storage section 2 is left to stand for a certain period of time.

[0035] [Comparative Example] As shown in FIG. 5, the coolant reservoir 2 has a moisture removal section 25 at the bottom, in which a water-absorbent resin serving as a moisture absorber 23 is enclosed in a mesh bag 24 with a mesh opening of about 1 mm. The coolant reservoir 2 is filled with a non-aqueous insulating coolant 3, water droplets 21 are added, and the coolant reservoir 2 is left to stand for a certain period of time.

[0036] [evaluation] In Examples 1 and 2, the difference in specific gravity caused the water droplets to sink and reach the upper surface of the moisture removal section, where they were absorbed by the moisture absorber, removing the moisture from the insulation cooling liquid. In the Comparative Example, on the other hand, the water droplets reached the upper surface of the moisture removal section, just as in Examples 1 and 2, but remained on the moisture removal section and were not absorbed by the moisture removal section, meaning that the moisture in the insulation cooling liquid could not be removed. This is presumably because the surface tension was stronger than the force that caused the water droplets to sink into the mesh bag due to their own weight, preventing the water droplets from passing through the mesh structure and reaching the surface of the moisture absorber inside the mesh bag. [Explanation of symbols]

[0037] 1...Circulation route 2...Coolant reservoir 3...Insulating coolant 4...Moisture removal section 5...Moisture absorber 100...Cooling system

Claims

1. a circulation path for circulating a non-aqueous insulating coolant; a cooling liquid reservoir provided in the circulation path and configured to store the insulating cooling liquid, The specific gravity of the insulating cooling liquid is less than that of water, the coolant reservoir has a moisture removal section therein, the water removal part is fixed to the cooling liquid reservoir so that at least a portion of an upper surface of the water removal part is in direct contact with the insulating cooling liquid; At least a portion of the water removal unit is fixed to a bottom surface of the coolant reservoir unit, A cooling system, wherein the moisture removal unit is arranged so as not to block either the inlet or outlet of the insulating cooling liquid in the cooling liquid reservoir.

2. The cooling system according to claim 1 , wherein the moisture removal unit contains porous zeolite or a water-absorbent resin as a moisture absorbent.

3. The moisture removal section contains the water-absorbing resin, 3. The cooling system according to claim 2, wherein the water-absorbing resin is at least one selected from the group consisting of a partially neutralized crosslinked product of polyacrylic acid, a neutralized product of a starch-acrylic acid graft polymer, a hydrolyzed product of a starch-acrylonitrile graft polymer, a saponified product of a vinyl acetate-acrylic acid ester copolymer, a crosslinked product of an isobutylene-maleic anhydride copolymer, a hydrolyzed product of an acrylonitrile copolymer or an acrylamide copolymer, or a crosslinked product thereof, a crosslinked product of an acrylate-acrylamide copolymer, a crosslinked product of a polyvinyl alcohol, a crosslinked product of a modified polyethylene oxide, a crosslinked product of an acrylamide-2-methylpropanesulfonate copolymer, a crosslinked product of a (meth)acryloylalkanesulfonate copolymer, a crosslinked carboxymethylcellulose salt, and a crosslinked polymer of a cationic monomer.

4. 4. The cooling system according to claim 3, wherein the water-absorbing resin is a crosslinked partially neutralized polyacrylic acid or a neutralized starch-acrylic acid graft polymer.

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