Novel Use of Low Conductivity Coolants

Abstract

This application describes the use of low conductivity coolants in the direct or indirect cooling of electronic devices.

Description

[Technical field]

[0001] This application describes the use of low conductivity coolants in the direct or indirect cooling of electronic devices. [Background technology]

[0002] In modern server farms, removing heat is a common problem to prevent overheating of electronic devices, especially hard disks, memories, microprocessors or central processing units (CPUs). When it is not possible to remove warm air with the help of fans, a heat transfer fluid is used to remove the generated heat. The heat transfer fluid thus warmed is then conveyed to a heat exchanger, cooled and circulated back in the loop.

[0003] As computing power increases in desktop computers, data centers, and communication centers, the amount of heat generated also increases.

[0004] Thus, devices such as personal computers operate with fans to cool the heat generated by components such as microprocessors, memory, and power supplies.

[0005] Communication centers and data centers, which are large networks of electronic devices, utilize large distributed air conditioning systems that may consist of multiple fans, blowers, compressors, and pumps to cool the air supplied to the devices. Through multiple heat transfer processes, heat is typically transferred to the outside air or groundwater. Power electronic equipment often utilizes large blowers to heat sinks attached to power electronic modules made up of semiconductor devices.

[0006] As the need for access to processing and storage resources continues to expand, the density of server systems (i.e., the amount of processing power and / or storage per server, the number of servers placed in a rack, and / or the number of servers and / or racks placed in a server farm) continues to increase. Although it is desirable to increase the processing and storage density of these server systems, the resulting heat problems remain a major obstacle. Traditional cooling systems (e.g., fan-based) require large amounts of power, and the power costs required to run such systems increase exponentially with increasing server density. As a result, there is a need for an efficient system that uses less power to cool the servers while allowing the desired increase in processing and / or storage density of the server systems.

[0007] The use of liquid cooling is becoming increasingly common in such devices: in many power electronic devices, the desired power density makes air cooling of the components inside them impractical, and in large data and communication centers, liquid cooling is being used to replace air in many of the heat transfer processes to increase energy efficiency.

[0008] Cooling can be direct (heat dissipating components are directly immersed in the heat transfer fluid) or indirect (heat is transferred through a thermal interface material).

[0009] Since water or water-based systems usually exhibit a certain electrical conductivity that can cause electrical short circuits when in direct contact with electrical components or if the coolant loop leaks in indirect cooling, organic liquids, especially fluorinated organic liquids (see for example WO 2020 / 250104 or WO 2018 / 224908), are usually used as heat transfer fluids.

[0010] On the other hand, organic heat transfer fluids often exhibit low flash points and are flammable, creating an unacceptable fire hazard. Fluorinated organic liquids are often non-flammable, but are environmentally problematic due to their ozone depletion potential and atmospheric lifetime.

[0011] WO 02 / 101848 and unpublished European Patent Application No. 20192954.4, filed August 26, 2020, both disclose low-conductivity water-based coolants for use in the cooling systems of vehicles equipped with electric, fuel cell, or hybrid engines. Applications for such coolants are limited to cooling fuel cells and electric vehicles, but other applications are not disclosed or obvious. Summary of the Invention [Problem to be solved by the invention]

[0012] It was an object of the present invention to provide an aqueous heat transfer fluid that can be used in direct contact with electronic components. [Means for solving the problem]

[0013] The purpose of this is to (A) at least one glycol (B)Water (C) at least one azole derivative (D) at least one ester of orthosilicic acid or an alkoxyalkylsilane (E) optionally, at least one tertiary amine having at least one 2-hydroxyethyl or 2-hydroxypropyl group; (F) Optionally, at least one monocarboxylic acid (G) optionally at least one silicophosphonate, and (H) Optionally, at least one additional coolant additive. A coolant comprising: The components (C) to (H) are present in an amount such that the coolant exhibits a conductivity of less than 100 μS / cm, preferably less than 50 μS / cm, more preferably less than 45 μS / cm.

[0014] In one preferred embodiment, both components (E) and (F) are absent.

[0015] In another preferred embodiment, both components (E) and (F) are present, but The molar ratio of the tertiary amine (E) to the monocarboxylic acid (F) is 1:0.1 to 1:0.6; Provided that components (C)-(H) are present in amounts such that the coolant exhibits a conductivity of less than 100 μS / cm, preferably less than 50 μS / cm, more preferably less than 45 μS / cm.

[0016] Such coolants exhibit both low electrical conductivity which allows them to be used as coolants in heat generating electronic devices, preferably electronic devices comprising data centers, more preferably electronic devices comprising data centers containing electronic components.

[0017] The advantage of the water-based coolant according to the invention is that it is non-flammable and exhibits a higher heat capacity than the organic or fluorinated organic liquids known in the prior art, which enhances the cooling effect. Furthermore, the water-based coolant according to the invention exhibits a higher boiling point and evaporation enthalpy than the organic or fluorinated organic liquids, respectively, and thus a lower vapor pressure at the operating temperature of the heat dissipating component. Thus, the coolant in the loop remains fluid without forming a second (gaseous) phase. In addition, the fluid is inert, which makes it compatible with the construction materials and electronic components.

[0018] Another object of the invention is the use of such a coolant for thermally managing a heat generating electronic device, preferably an electronic device comprising a data center, more preferably an electronic device comprising a data center containing electronic components.

[0019] Another object of the present invention is a method for thermally managing a heat generating electronic device, preferably an electronic device comprising a data center, more preferably an electronic device comprising a data center containing electronic components, by directly or indirectly contacting the heat generating electronic device with a coolant, conveying the coolant to a heat exchanger and recirculating such water-based coolant.

[0020] The method may include at least partially submerging a heat-generating component (e.g., a computer server) in the water-based coolant. The method may further include transferring heat from the heat-generating component using the water-based coolant.

[0021] Another object of the present invention is to provide and electronic devices that generate heat; a thermal management system including at least one recirculating thermal management fluid, the thermal management system being designed to transfer heat away from a heat-generating electronic device; The system includes:

[0022] The system can be designed as a liquid immersion cooling system including a housing having an interior space; a heat-generating component disposed within the interior space; and a working fluid liquid disposed within the interior space such that the heat-generating component contacts the working fluid liquid. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] In some embodiments, heat-generating components may be disposed within the interior space such that they are at least partially immersed (up to completely immersed) in the liquid phase of the working fluid.

[0024] In some embodiments, the heat-generating components may include one or more electronic devices, such as a computing server.

[0025] In some embodiments, the present disclosure may relate to an immersion cooling system that operates by single-phase immersion cooling. In general, a single-phase immersion cooling system is similar to a two-phase system in that it may include a heat-generating component disposed within an interior space of a housing such that it is at least partially immersed (up to completely immersed) in a liquid phase of a working fluid. The single-phase system may further include a pump and a heat exchanger, where the pump operates to move the working fluid to and from the heat-generating component and the heat exchanger, and the heat exchanger operates to cool the working fluid. The heat exchanger may be disposed within the housing or external to the housing.

[0026] "Thermal management fluid" and "heat transfer fluid" and "heat transfer medium" and "coolant" are used interchangeably herein and refer to fluids capable of transferring heat from one location to another.

[0027] The detailed ingredients are as follows: Glycol (A) As alkylene glycol component or derivative thereof (A) it is possible to use, in particular, monoethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol and mixtures thereof, but also monopropylene glycol, dipropylene glycol and mixtures thereof, 1,3-propanediol, higher polyalkylene glycols, alkylene glycol ethers, such as monoethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, tetraethylene glycol monomethyl ether, monoethylene glycol monoethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, tetraethylene glycol monoethyl ether, monoethylene glycol mono-n-butyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol mono-n-butyl ether and tetraethylene glycol mono-n-butyl ether, or glycerol, in each case alone or as mixtures thereof.

[0028] Water (B) The water used in the coolant according to the present invention should be ion-free, which means water that has a neutral pH value and is essentially free of other ions other than hydroxide and hydronium ions from the autoprotonation of water at the respective temperature.

[0029] The conductivity of the ion-free water used at 25° C. (determined throughout this specification according to ASTM D1125) should preferably be 5 μS / cm or less, more preferably 3 μS / cm or less, even more preferably 2 μS / cm or less, especially 1 μS / cm or less.

[0030] The ion-free water used may be pure distilled or double-distilled water or water deionized, for example by ion exchange.

[0031] Azole Derivatives (C) Azole derivatives in the context of the present invention are understood to mean 5-membered heterocyclic compounds which may have aromatic or saturated 6-membered fused rings, which have 2 or 3 heteroatoms from the group consisting of nitrogen and sulfur, and which contain no or at most one sulfur atom.

[0032] These five-membered heterocyclic compounds (azole derivatives) usually contain two N atoms and no S atoms, three N atoms and no S atoms, or one N atom and one S atom as heteroatoms.

[0033] A preferred group of specific azole derivatives are the fused imidazoles and fused 1,2,3-triazoles of the general formula [ka] where the variable R is hydrogen or C 1 ~C 10 an alkyl radical, specifically methyl or ethyl, and the variable X being a nitrogen atom or a CH group).

[0034] Typical and preferred examples of the azole derivatives of general formula (I) are benzimidazole (X=CH, R=H), benzotriazole (X=N, R=H), and tolutriazole (X=N, R=CH 3 A typical example of an azole derivative of the general formula (II) is hydrogenated 1,2,3-tolutriazole (X=N, R=CH 3 ).

[0035] A further preferred group of specific azole derivatives are the benzothiazoles of general formula (III) [ka] where the variable R is as defined above and the variable R′ is hydrogen, C 1 ~C 10 An alkyl radical, in particular methyl or ethyl, or in particular a mercapto group (-SH). A typical example of an azole derivative of general formula (III) is 2-mercaptobenzothiazole.

[0036] Less preferred is (2-benzothiazylthio)acetic acid (R' = SCH 2 COOH) or (2-benzothiazylthio)propionic acid (R' = -S-CH 2 -CH 2 It is also possible to use free acid compounds such as aryloxycarbonyl ether (-COOH). This embodiment is less preferred since the use of such free acid compounds increases the electrical conductivity of the coolant.

[0037] Further suitable azole derivatives are non-fused azole derivatives of the general formula (IV) [ka] where the variables X and Y together are two nitrogen atoms or one nitrogen atom and a CH group, such as 1H-1,2,4-triazole (X=Y=N) or preferably imidazole (X=N, Y=CH).

[0038] For the purposes of the present invention, benzimidazole, benzotriazole, tolutriazole, hydrogenated tolutriazole or mixtures thereof, especially benzotriazole or tolutriazole, are highly preferred as azole derivatives.

[0039] The azole derivatives mentioned are commercially available or can be prepared by conventional methods. Hydrogenated benzotriazoles, such as hydrogenated tolutriazole, are likewise available as described in DE 1948794 A1 and are also commercially available.

[0040] Esters of orthosilicic acid or alkoxyalkylsilanes (D) Esters of orthosilicic acid are compounds of the formula Si(OR 1 ) 4 (In the formula, R 1 is an organic substituent containing 1 to 6 carbon atoms, for example a linear or branched, preferably linear alkyl substituent containing 1 to 6 carbon atoms, or an aromatic substituent containing 6 carbon atoms, more preferably an alkyl substituent containing 1 to 4 carbon atoms, and even more preferably an alkyl substituent containing 1 or 2 carbon atoms).

[0041] Less preferred are alkoxyalkylsilanes in which both the alkoxy substituent and the alkyl group are straight or branched, preferably straight chain alkyl substituents containing 1 to 6 carbon atoms, more preferably alkyl substituents containing 1 to 4 carbon atoms, and even more preferably alkyl substituents containing 1 or 2 carbon atoms.

[0042] Typical examples of compounds (D) are tetraalkoxysilanes, preferably tetramethoxysilane and tetraethoxysilane, and alkoxyalkylsilanes, preferably triethoxymethylsilane, diethoxydimethylsilane, ethoxytrimethylsilane, trimethoxymethylsilane, dimethoxydimethylsilane, and methoxytrimethylsilane. Tetraalkoxysilanes are preferred, tetramethoxysilane and tetraethoxysilane are particularly preferred, and tetraethoxysilane is very particularly preferred.

[0043] Compound (D) is primarily used as a corrosion inhibitor for aluminum.

[0044] Tertiary amine (E) (optional) At least one tertiary amine (E) has at least one 2-hydroxyethyl or 2-hydroxypropyl group. Possible tertiary amines (E) may have 1, 2 or 3 2-hydroxyethyl or 2-hydroxypropyl groups, preferably 2 or 3 2-hydroxyethyl or 2-hydroxypropyl groups, more preferably 2-hydroxyethyl groups.

[0045] The substituents of the tertiary amine (E), which are not 2-hydroxyethyl or 2-hydroxypropyl groups, may be aliphatic, alicyclic or aromatic groups having up to 20 carbon atoms, preferably up to 18, more preferably up to 16, even more preferably up to 14 and especially up to 12 carbon atoms.

[0046] These substituents are preferably aliphatic or aromatic, more preferably aliphatic.

[0047] The aromatic substituent may be, for example, phenyl, tolyl, or naphthyl.

[0048] The aliphatic substituents may be linear or branched, and preferred are linear alkyl substituents containing 1 to 18 carbon atoms, preferably 2 to 16, more preferably 4 to 14, and especially 6 to 12 carbon atoms.

[0049] In the compounds (E), the substituents are preferably obtained by hydrogenation and amination of fatty acids and esters, particularly preferably 2-ethylhexanoic acid, octanoic acid (caprylic acid), pelargonic acid (nonanoic acid), 2-propylheptanoic acid, decanoic acid (capric acid), undecanoic acid, dodecanoic acid (lauric acid), tridecanoic acid, tetradecanoic acid (myristic acid), pentadecanoic acid, palmitic acid (hexadecanoic acid), palmitoleic acid [(9Z)-hexadec-9-enoic acid], margaric acid (heptadecanoic acid), stearic acid (octadecanoic acid), oleic acid [(9Z)-octadec-9-enoic acid], elaidic acid [(9E)-octadec-9-enoic acid], It is derived from fatty amines obtained by hydrogenation and amination of linoleic acid [(9Z,12Z)-octadeca-9,12-dienoic acid], linolenic acid [(9Z,12Z,15Z)-octadeca-9,12,15-trienoic acid], eleostearic acid [(9Z,11E,13E)-octadeca-9,11,13-trienoic acid], ricinoleic acid ((R)-12-hydroxy-(Z)-octadec-9-enoic acid), isoleucinolic acid [(S)-9-hydroxy-(Z)-octadec-12-enoic acid], nonadecanoic acid, arachidic acid (eicosanoic acid), behenic acid (docosanoic acid), and erucic acid [(13Z)-docos-13-enoic acid].

[0050] Examples of tertiary amines (E) having one 2-hydroxyethyl or 2-hydroxypropyl group and two other substituents are those of the general formula (I) [ka] (In the formula, R 2 and R 3 are each independently of one another the above-mentioned substituents, preferably linear or branched, preferably linear alkyl substituents containing 1 to 18 carbon atoms, preferably 2 to 16, more preferably 4 to 14, particularly preferably 6 to 12 carbon atoms, or may together form a 5- or 6-membered ring containing a nitrogen atom, X i is -CH 2-CH 2 -O-, -CH 2 -CH(CH 3 )-O-, or -CH(CH 3 )-CH 2 -O-, preferably -CH 2 -CH 2 -O-, n is a positive integer of 1 to 5, preferably 1 to 4, more preferably 1 to 3, further preferably 1 or 2, and particularly preferably 1.

[0051] Preferred specific materials are dimethylethanolamine, dimethylpropanolamine, diethylethanolamine, diethylpropanolamine, di-n-butylethanolamine, di-n-butylpropanolamine, N-hydroxyethylpyrrolidine, N-hydroxyethylpiperidine, and N-hydroxyethylmorpholine.

[0052] Examples of tertiary amines (E) having two 2-hydroxyethyl or 2-hydroxypropyl groups and one other substituent are those of the general formula (II) [ka] (In the formula, R 4 is the substituent as mentioned above, preferably a linear or branched, preferably linear, alkyl substituent containing 1 to 18 carbon atoms, preferably 2 to 16, more preferably 4 to 14, in particular 6 to 12 carbon atoms, Each Xi of i=1 to p and 1 to q is -CH 2 -CH 2 -O-, -CH 2 -CH(CH 3 )-O-, or -CH(CH 3 )-CH 2 -O-, preferably -CH 2 -CH 2 -O-, p and q each independently represent a positive integer of 1 to 5, preferably 1 to 4, more preferably 1 to 3, further preferably 1 or 2, and particularly preferably 1.

[0053] Preferred specific substances include the substituent R 4 and bis(2-hydroxyethyl)amine or bis(2-hydroxypropyl)amine having as the amine anhydride n-hexylamine, 2-methylpentylamine, n-heptylamine, 2-heptylamine, isoheptylamine, 1-methylhexylamine, n-octylamine, 2-ethylhexylamine, 2-aminooctane, 6-methyl-2-heptylamine, n-nonylamine, isononylamine, n-decylamine, and 2-propylheptylamine, or mixtures thereof.

[0054] Particularly preferred are the bis(2-hydroxyethyl) substituted n-hexylamines, n-octylamine, 2-ethylhexylamine, and n-decylamines, with n-octylamine and 2-ethylhexylamine, especially bis(2-hydroxyethyl) n-octylamine, being especially preferred.

[0055] These compounds can be converted, preferably under basic conditions, to the corresponding amines R 4 -NH 2 can be preferably obtained by reacting the structural unit X with an alkylene oxide to the desired average statistical degree of alkoxylation. i It is particularly preferred when is derived from ethylene oxide or propylene oxide, preferably ethylene oxide.

[0056] Examples of tertiary amines (E) having three 2-hydroxyethyl or 2-hydroxypropyl groups are triethanolamine and tripropanolamine, preferably triethanolamine.

[0057] Preferred amines (E) are dimethylethanolamine, dimethylpropanolamine, diethylethanolamine, di-n-butylethanolamine, N-hydroxyethylmorpholine, bis(2-hydroxyethyl)n-hexylamine, bis(2-hydroxyethyl)n-octylamine, bis(2-hydroxyethyl)2-ethylhexylamine, bis(2-hydroxyethyl)n-decylamine, and triethanolamine.

[0058] Monocarboxylic acid (F) (optional) Suitable monocarboxylic acids (F) may be linear or branched, aliphatic, alicyclic or aromatic monocarboxylic acids having up to 20 carbon atoms, preferably 2 to 18, more preferably 5 to 16, even more preferably 5 to 14, most preferably 6 to 12 and especially 8 to 10 carbon atoms.

[0059] Branched chain aliphatic monocarboxylic acids are preferred over the corresponding straight chain monocarboxylic acids.

[0060] Useful linear or branched, aliphatic or cycloaliphatic monocarboxylic acids (F) are, for example, propionic acid, pentanoic acid, 2,2-dimethylpropanoic acid, hexanoic acid, 2,2-dimethylbutanoic acid, cyclohexylacetic acid, octanoic acid, 2-ethylhexanoic acid, nonanoic acid, isononanoic acid, decanoic acid, undecanoic acid or dodecanoic acid.

[0061] Suitable aromatic monocarboxylic acids (F) are in particular benzoic acid, and also C benzoic acids such as, for example, o-, m-, p-methylbenzoic acid or p-tert-butylbenzoic acid. 1 ~C 8 Also useful are alkyl benzoic acids and hydroxyl-containing aromatic monocarboxylic acids such as o-, m-, or p-hydroxybenzoic acid, o-, m-, or p-(hydroxymethyl)benzoic acid, or halobenzoic acids such as o-, m-, or p-fluorobenzoic acid.

[0062] 2-Ethylhexanoic acid and isononanoic acid are particularly preferred.

[0063] As used herein, isononanoic acid refers to one or more branched chain aliphatic carboxylic acids having 9 carbon atoms. The embodiments of isononanoic acid used in engine coolant compositions include 7-methyloctanoic acid (e.g., CAS No. 693-19-6 and 26896-18-4), 6,6-dimethylheptanoic acid (e.g., CAS No. 15898-92-7), 3,5,5-trimethylhexanoic acid (e.g., CAS No. 3302-10-1), 3,4,5-trimethylhexanoic acid, 2,5,5-trimethylhexanoic acid, 2,2,4,4-tetramethylpentanoic acid (e.g., CAS No. 3302-12-3), and combinations thereof. In a preferred embodiment, the isononanoic acid comprises one of 7-methyloctanoic acid, 6,6-dimethylheptanoic acid, 3,5,5-trimethylhexanoic acid, 3,4,5-trimethylhexanoic acid, 2,5,5-trimethylhexanoic acid, and 2,2,4,4-tetramethylpentanoic acid as greater than 90% of the major component. The remainder of the isononanoic acid may comprise other 9-carbon carboxylic acid isomers and small amounts of one or more contaminants. In a preferred embodiment, the isononanoic acid has 3,5,5-trimethylhexanoic acid as greater than 90% of the major component, and more preferably, the major component is 3,5,5-trimethylhexanoic acid at greater than 95%.

[0064] However, it is also possible, although disadvantageous, to use carboxylic acids with higher functionality, such as dicarboxylic acids or tricarboxylic acids, in addition to or instead of monocarboxylic acids.It has been shown that the use of monocarboxylic acids gives superior results compared to the commonly used dicarboxylic acids (see examples).

[0065] When used, the di- or tricarboxylic acids can be aliphatic, alicyclic or aromatic, preferably aliphatic or aromatic, more preferably aliphatic having up to 20 carbon atoms, preferably up to 18, more preferably up to 16, even more preferably up to 14, especially up to 12 carbon atoms.

[0066] Examples of dicarboxylic acids, if used, are oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, alkyl or alkenyl succinic acid, 2-methylbutanedioic acid, 2-ethylpentanedioic acid, 2-n-dodecylbutanedioic acid, 2-n-dodecenylbutanedioic acid, 2-phenylbutanedioic acid, 2-(p-methylphenyl)butanedioic acid, 2,2-dimethylbutanedioic acid, 2,3-dimethylbutanedioic acid; 2,3,4 trimethylpentanedioic acid, 2,2,3-trimethylpentanedioic acid; 2-ethyl 3-Methylbutanedioic acid, maleic acid, fumaric acid, pent-2-enedioic acid, hex-2-enedioic acid; hex-3-enedioic acid; 5-methylhex-2-enedioic acid; 2,3-dimethylpent-2-enedioic acid; 2-methylbut-2-enedioic acid, 2-dodecylbut-2-enedioic acid, phthalic acid, isophthalic acid, terephthalic acid, and substituted phthalic acids, such as 3-methylbenzene-1,2-dicarboxylic acid; 4-phenylbenzene-1,3-dicarboxylic acid; 2-(1-propenyl)benzene-1,4-dicarboxylic acid, and 3,4-dimethylbenzene-1,2-dicarboxylic acid.

[0067] Examples of tricarboxylic acids, if used, are benzenetricarboxylic acid (all isomers) and triazinetriiminocarboxylic acids such as 6,6',6''-(1,3,5-triazine-2,4,6-triyltriimino)trihexanoic acid.

[0068] In a preferred embodiment, the coolant according to the present invention does not contain any carboxylic acids with a functionality greater than one.

[0069] Silicophosphonate (G) As an optional component, it is possible to use at least one silicophosphonate (G) in the coolant according to the invention.

[0070] The silicophosphonates are of the general structure (V) [ka] (In the formula, R 5 is a divalent organic residue, preferably a 1,ω-alkylene group having 1 to 6, preferably 1 to 6, preferably 1 to 4 carbon atoms, more preferably methylene, 1,2-ethylene, 1,2-propylene, 1,3-propylene or 1,4-butylene, most preferably 1,2-ethylene or 1,3-propylene, in particular 1,2-ethylene, R 6 and R 7 are independent of each other, C 1 ~C 4 -alkyl, preferably methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl or tert-butyl, preferably methyl or ethyl).

[0071] Such silicophosphonates may be present as the free phosphonate acid or in the form of their sodium or potassium salts, preferably the sodium or potassium salts, more preferably the sodium salts.

[0072] Additional Coolant Additives (H) Additional typical coolant additives may be added to the coolant of the present invention as long as they do not increase the electrical conductivity beyond the critical value.

[0073] Typical such coolant additives may be corrosion inhibitors against tin, silver, and solder corrosion.

[0074] As additional general adjuvants, the coolant of the invention may also contain, usually in small amounts, antifoaming agents (generally in amounts of 0.003-0.008% by weight), as well as bitter substances (for example of the denatonium benzoate type) for reasons of hygiene and safety when swallowed, and dyes.

[0075] It is preferred to use non-ionic additives rather than ionic additives whenever possible, insofar as similar effects can be achieved using non-ionic additives.

[0076] composition The main requirement of the coolant according to the invention is that it must exhibit an electrical conductivity (measured according to ASTM D1125) of less than 50 μS / cm, preferably less than 45 μS / cm at 25° C., in order to be suitable for the cooling systems of vehicles equipped with electric engines.

[0077] To achieve that goal, the amounts of ionic species, species that may contain ionic by-products, or combinations of species that may form ions, such as acids and bases, must be minimized so that the conductivity does not exceed a critical value.

[0078] Therefore, the amounts of components (C)-(H) in the coolant are selected so as not to exceed the critical value of electrical conductivity.

[0079] Typically, a coolant according to the present invention is composed as follows: (A) At least one glycol: 10 to 90% by weight, preferably 20 to 80% by weight, more preferably 30 to 70% by weight (B) Water: 10 to 90% by weight, preferably 20 to 80% by weight, more preferably 30 to 70% by weight (C) At least one azole derivative: 0.01 to 1% by weight, preferably 0.02 to 0.9% by weight, more preferably 0.03 to 0.8% by weight, further preferably 0.04 to 0.5, particularly preferably 0.05 to 0.3% by weight (D) At least one kind of orthosilicic acid ester or alkoxyalkylsilane: 0.01 to 1% by weight, preferably 0.02 to 0.9% by weight, more preferably 0.03 to 0.8% by weight, even more preferably 0.04 to 0.5, particularly preferably 0.05 to 0.3% by weight (G) Optionally, at least one silicophosphonate: 0 to 1% by weight, preferably 0.01 to 0.8% by weight, more preferably 0.02 to 0.6% by weight (H) Optionally, at least one additional coolant additive: 0 to 0.5 wt. %, preferably 0.01 to 0.4 wt. %, more preferably 0.02 to 0.3 wt. % for each additional coolant additive. provided that the sum of all components is always 100% by weight, and in which the tertiary amine (E) and the monocarboxylic acid (F) are absent.

[0080] In another embodiment, the tertiary amine (E) and / or the monocarboxylic acid (F), preferably both (E) and (F), are present in the amounts specified below.

[0081] To keep the combination of ion-forming species to a minimum, the molar ratio of tertiary amine (E) to monocarboxylic acid (F) is 1:0.1 to 1:0.6, preferably 0.15 to 0.5, more preferably 0.2 to 0.4.

[0082] Reference is made to the number of amino and carboxylic acid groups in compounds (E) and (F) when molecules with functionality greater than 1 are used.

[0083] Typically, a coolant according to the present invention is composed as follows: (A) At least one glycol: 10 to 90% by weight, preferably 20 to 80% by weight, more preferably 30 to 70% by weight (B) Water: 10 to 90% by weight, preferably 20 to 80% by weight, more preferably 30 to 70% by weight (C) At least one azole derivative: 0.01 to 1% by weight, preferably 0.02 to 0.9% by weight, more preferably 0.03 to 0.8% by weight, further preferably 0.04 to 0.5, particularly preferably 0.05 to 0.3% by weight (D) At least one kind of orthosilicic acid ester or alkoxyalkylsilane: 0.01 to 1% by weight, preferably 0.02 to 0.9% by weight, more preferably 0.03 to 0.8% by weight, even more preferably 0.04 to 0.5, particularly preferably 0.05 to 0.3% by weight (E) At least one tertiary amine having at least one 2-hydroxyethyl group or 2-hydroxypropyl group: 0.01 to 1% by weight, preferably 0.015 to 0.9% by weight, more preferably 0.02 to 0.8% by weight. (F) At least one monocarboxylic acid: 0.01 to 1% by weight, preferably 0.015 to 0.8% by weight, more preferably 0.02 to 0.6% by weight. (G) Optionally, at least one silicophosphonate: 0 to 1% by weight, preferably 0.01 to 0.8% by weight, more preferably 0.02 to 0.6% by weight (H) Optionally, at least one additional coolant additive: 0 to 0.5 wt. %, preferably 0.01 to 0.4 wt. %, more preferably 0.02 to 0.3 wt. % for each additional coolant additive. provided, however, that the total of all components always equals 100% by weight.

[0084] A further embodiment of the present invention is a coolant concentrate. A coolant is typically obtained from the coolant concentrate by dilution with water (B). Thus, the coolant concentrate typically contains little or no water (B).

[0085] Typically, in one embodiment, a coolant concentrate according to the present invention is composed as follows: (A) At least one glycol: 50 to 99.9% by weight, preferably 60 to 99.8% by weight, more preferably 75 to 99.7% by weight (B) Water: 0 to 10% by weight, preferably 0 to 8% by weight, more preferably 0 to 5% by weight (C) At least one azole derivative: 0.02 to 1% by weight, preferably 0.04 to 0.8% by weight, more preferably 0.06 to 0.6% by weight, further preferably 0.08 to 0.5, particularly preferably 0.1 to 0.4% by weight (D) at least one ester of orthosilicic acid or alkoxyalkylsilane, 0.02 to 1% by weight, preferably 0.04 to 0.8% by weight, more preferably 0.06 to 0.6% by weight, even more preferably 0.08 to 0.5% by weight, and particularly preferably 0.1 to 0.4% by weight (E) At least one tertiary amine having at least one 2-hydroxyethyl group or 2-hydroxypropyl group: 0.02 to 0.8% by weight, preferably 0.03 to 0.6% by weight, more preferably 0.04 to 0.5% by weight. (F) At least one monocarboxylic acid: 0.01 to 0.5% by weight, preferably 0.02 to 0.3% by weight, more preferably 0.03 to 0.2% by weight (G) Optionally, at least one silicophosphonate: 0 to 1% by weight, preferably 0.02 to 0.8% by weight, more preferably 0.04 to 0.6% by weight. (H) Optionally, at least one additional coolant additive: 0 to 0.5 wt. %, preferably 0.002 to 0.4 wt. %, more preferably 0.004 to 0.3 wt. % for each additional coolant additive. provided, however, that the total of all components always equals 100% by weight.

[0086] In another embodiment, the coolant concentrate according to the present invention does not contain components (E) and (F) and is composed as follows: (A) At least one glycol: 50 to 99.9% by weight, preferably 60 to 99.8% by weight, more preferably 75 to 99.7% by weight (B) Water: 0 to 10% by weight, preferably 0 to 8% by weight, more preferably 0 to 5% by weight (C) At least one azole derivative: 0.02 to 1% by weight, preferably 0.04 to 0.8% by weight, more preferably 0.06 to 0.6% by weight, further preferably 0.08 to 0.5, particularly preferably 0.1 to 0.4% by weight (D) At least one kind of orthosilicic acid ester or alkoxyalkylsilane: 0.02 to 1% by weight, preferably 0.04 to 0.8% by weight, more preferably 0.06 to 0.6% by weight, even more preferably 0.08 to 0.5, particularly preferably 0.1 to 0.4% by weight (G) Optionally, at least one silicophosphonate: 0 to 1% by weight, preferably 0.02 to 0.8% by weight, more preferably 0.04 to 0.6% by weight. (H) Optionally, at least one additional coolant additive: 0 to 0.5 wt. %, preferably 0.002 to 0.4 wt. %, more preferably 0.004 to 0.3 wt. % for each additional coolant additive. provided, however, that the total of all components always equals 100% by weight.

[0087] A further embodiment of the present invention is a coolant super concentrate. A coolant concentrate is typically obtained from a coolant super concentrate by dilution with glycol (A), but each coolant can be obtained from the coolant super concentrate by dilution with glycol (A) and water (B). Thus, a coolant concentrate typically contains little or no water (B) and little or no glycol (A).

[0088] Typically, in one embodiment, a coolant ultra concentrate according to the present invention is comprised as follows: (A) At least one glycol: 70 to 99.5% by weight, preferably 80 to 99% by weight, more preferably 90 to 98% by weight (B) Water: 0 to 10% by weight, preferably 0 to 8% by weight, more preferably 0 to 5% by weight (C) At least one azole derivative: 0.05 to 5% by weight, preferably 0.1 to 4% by weight, more preferably 0.2 to 3% by weight, further preferably 0.3 to 2% by weight, particularly preferably 0.4 to 1.5% by weight (D) At least one kind of orthosilicic acid ester or alkoxyalkylsilane: 0.05 to 5% by weight, preferably 0.1 to 4% by weight, more preferably 0.2 to 3% by weight, even more preferably 0.3 to 2, particularly preferably 0.4 to 1.5% by weight. (E) at least one tertiary amine having at least one 2-hydroxyethyl group or 2-hydroxypropyl group: 0.1 to 4% by weight, preferably 0.15 to 3% by weight, more preferably 0.2 to 2.5% by weight (F) At least one monocarboxylic acid: 0.05 to 1% by weight, preferably 0.1 to 0.9% by weight, more preferably 0.2 to 0.8% by weight (G) Optionally, at least one silicophosphonate: 0 to 5% by weight, preferably 0.02 to 4% by weight, more preferably 0.04 to 3% by weight (H) Optionally, at least one additional coolant additive: 0 to 1 wt. %, preferably 0.005 to 0.8 wt. %, more preferably 0.008 to 0.6 wt. % for each additional coolant additive. provided, however, that the total of all components always equals 100% by weight.

[0089] In another embodiment, the coolant super concentrate according to the present invention does not include components (E) and (F) and is comprised as follows: (A) At least one glycol: 70 to 99.5% by weight, preferably 80 to 99% by weight, more preferably 90 to 98% by weight (B) Water: 0 to 10% by weight, preferably 0 to 8% by weight, more preferably 0 to 5% by weight (C) At least one azole derivative: 0.05 to 5% by weight, preferably 0.1 to 4% by weight, more preferably 0.2 to 3% by weight, further preferably 0.3 to 2% by weight, particularly preferably 0.4 to 1.5% by weight (D) At least one kind of orthosilicic acid ester or alkoxyalkylsilane: 0.05 to 5% by weight, preferably 0.1 to 4% by weight, more preferably 0.2 to 3% by weight, even more preferably 0.3 to 2, particularly preferably 0.4 to 1.5% by weight. (G) Optionally, at least one silicophosphonate: 0 to 5% by weight, preferably 0.02 to 4% by weight, more preferably 0.04 to 3% by weight (H) Optionally, at least one additional coolant additive: 0 to 1 wt. %, preferably 0.005 to 0.8 wt. %, more preferably 0.008 to 0.6 wt. % for each additional coolant additive. provided, however, that the total of all components always equals 100% by weight.

[0090] The coolant according to the present invention has low electrical conductivity and can therefore be used in cooling systems for cooling electronic devices.

[0091] system The heat-generating electronic device may be any electronic device or system that typically includes heat-generating electronic elements. Exemplary heat-generating electronic elements include semiconductor integrated circuits (ICs), power transistors, resistors, and electroluminescent elements. Electronic devices may include, but are not limited to, microprocessors, wafers used in the manufacture of semiconductor devices, power control semiconductors, circuit boards, multi-chip modules, packaged or unpackaged semiconductor devices, and semiconductor integrated circuits. Other devices include personal computers, microprocessors, servers, mobile phones, and personal digital assistants. Data centers are collections of computer systems and related components, such as telecommunications and storage systems that typically include redundant and / or backup power sources, redundant data communication connections, environmental controls (e.g., air conditioning, fire suppression, etc.), and security devices, and are also included within the scope of the provided protection system.

[0092] Such heat-generating electronic devices may be mobile or non-mobile.

[0093] Examples of non-mobile devices are data centers, telecommunications, and storage systems.

[0094] Examples of mobile devices are personal computers, microprocessors, mobile phones, and personal digital assistants, or devices installed in vehicles such as automobiles, airplanes, or boats.

[0095] In a preferred embodiment, the present invention can be used to cool electronic devices having voltages of 60 V or less, preferably 50 V or less, more preferably 40 V or less, and even more preferably 35 V or less. The voltage refers to the portion of the device in direct contact with the coolant.

[0096] In a particularly preferred embodiment, the applied voltage is 25V or less, preferably 20V or less, more preferably 15V or less, and even more preferably 12V or less.

[0097] Devices subject to higher voltages, such as power supply units and transformers, can be cooled according to the invention, however, at higher voltages, such as 110V or 220V, the extent of electrolysis of the coolant, such as the water in the coolant, increases. Therefore, in this case measures must be taken to remove the ionic products of hydrolysis (see below).

[0098] The electronic device includes a thermal management system that includes at least one recirculating thermal management fluid. The thermal management system is designed to transfer heat from a heat-generating electronic device to a condenser or heat exchanger. The thermal management system can recirculate the thermal management fluid passively or by using a mechanical device, such as a pump. A passive recirculation system works by transferring heat from the electronic device to the thermal management fluid, typically until it vaporizes, and then passing the heated vapor to a condenser where it transfers heat to the condenser surface, condenses back into a liquid, and then re-enters the condensed liquid into the thermal management fluid in contact with the electronic device.

[0099] In a preferred embodiment, the cooling fluid of the present invention does not evaporate and the cooling system operates well below the boiling point of the coolant, so no phase transfer occurs, and therefore the system of the present invention includes a heat exchanger but no condenser.

[0100] Passive thermal management systems may include, for example, single-phase or two-phase immersion cooling. In another embodiment, the thermal management system may include a pumped two-phase system. Thermal management systems may also include equipment for managing the heat transfer fluid, including, for example, pumps, valves, fluid containment systems, pressure control systems, condensers, heat exchangers, heat sources, heat sinks (usually outside air, groundwater, or river water), refrigeration systems, active temperature control systems, temperature and / or pressure sensors, flame sensors, carbon dioxide sensors, and passive temperature control systems.

[0101] The system provided includes a non-flammable and inert aqueous heat transfer medium according to the present invention. By non-flammable, it is meant that the medium does not readily support combustion (e.g., does not exhibit a flash point according to ASTM D-3278-96e-1 "Flash Point of Liquids by Small Scale Closed-Cup Apparatus"). As an aqueous medium, the heat transfer medium according to the present invention is non-flammable and does not exhibit a flash point due to sufficient water content. By inert, it is meant that the medium does not substantially react with components of the system or electronic device under normal operating conditions of the system.

[0102] In some cases, water-based coolants have the disadvantage that they can cause corrosion of the coolant circuit and metal-based components of the system. Furthermore, cooling media with a certain conductivity have safety issues. In addition, degradation of the coolant components can produce compounds that increase the conductivity, such as acids as oxidation products of glycols.

[0103] Since the electrical conductivity of the aqueous cooling medium decreases with the decrease in ion concentration, it has already been proposed to use a deionized cooling medium in fuel cells. For example, U.S. Pat. No. 5,200,278 and WO 00 / 17951 disclose the placement of ion exchangers in the cooling circuit to keep the aqueous coolant substantially free of ionic impurities for a certain period of time. However, a drawback of the known systems is that the ion exchangers wear out after a certain operating time and must be replaced.

[0104] In a preferred embodiment, it is proposed according to the invention to carry out at least intermittent electrochemical deionization of the cooling medium circulating in the cooling circuit. The process according to the invention allows the cooling circuit of the system to be operated virtually maintenance-free. For example, as soon as an increase in the conductivity of the cooling medium, corresponding to an increase in the ion concentration, is registered by a conductivity sensor, a voltage can be applied to the electrodes of an electrochemical cell arranged in the cooling circuit. This removes a portion of the ions from the cooling circuit. Preferably, an electrodialysis cell is used, which can be operated with or without an ion exchanger. If an ion exchanger is used, the corresponding cell is also called an electrode ionization cell. In this type of cell, deionization of the medium and regeneration of the ion exchanger take place simultaneously.

[0105] In the cooling circuit one or more heat exchangers are arranged. According to a variant of the invention, the first cooling circuit is at the same time the only cooling circuit, the one or more heat exchangers being in contact with, for example, a heat sink, for example air or water or another suitable cooling medium. However, the first cooling circuit, as a primary circuit, may also be in thermal contact with a second circuit (secondary circuit).

[0106] According to a preferred embodiment of the method according to the invention, the deionization of the cooling medium is carried out continuously during operation of the system.

[0107] Since the use of an ion exchanger allows the cooling medium to have a lower residual conductivity than in the case of pure electrodialysis, it is preferred to use an electrode ionization cell, with the cooling medium passing through the cell as a dilute stream.

[0108] Electrode ionization cells are known per se and are used, for example, for the desalination of seawater. This type of electrode ionization cell can, for example, consist of a mixed bed of anion and cation exchange resins. According to another variant, the anion and cation exchange resins are arranged in two separate chambers.

[0109] The diluent flow is advantageously cooled prior to deionization in order to keep the temperature of the solution in contact with the ion exchanger components low. For this purpose, the electrode ionization cell can be arranged, for example, downstream of the cooler or heat exchanger (based on the diluent flow direction) in the first cooling circuit.

[0110] According to a particularly preferred variant, the first cooling circuit is designed as a primary cooling circuit, in which the diluent stream with reduced ions comes into contact with the components at risk of corrosion. The concentrate stream from the electrode ionization cell can then circulate in a second cooling circuit, the secondary cooling circuit, and be cooled in the primary heat exchanger. The cooled concentrate stream can then be used to cool the diluent stream. The secondary circuit of the concentrate stream can have a water supply that can compensate for the water losses occurring in operation during the regeneration of the ion exchanger. In this variant, the heat from the diluent stream, after leaving the device generating heat, is preferably transferred via a primary cooler to a secondary circuit containing the concentrate stream. The cooled diluent stream then passes through the electrode ionization cell. The heated concentrate stream passes through the primary cooler and then enters the electrode ionization cell, where it picks up the ions migrating from the diluent.

[0111] The invention also relates to a system having at least one heat-generating device and a first cooling circuit for said heat-generating device, in which at least one electrode ionization cell is arranged through which a diluent flow and a concentrate flow, acting as cooling media. It is possible to use a wide variety of electrode ionization cells known per se (see for example Ganzi et al. "Electrodeionization", Ultrapure Water, July / -August 1997).

[0112] The electrodes of the electrode ionization cell can also be made of suitable materials, for example noble metals, especially platinum, metal oxides, or graphite. The cathode can be made of steel or nickel, for example. The membrane spacing is usually from a few hundred μm to a few cm. The current density depends on the residual conductivity of the solution and can be from a few mA / m2 to a few A / m2. For continuous operation, the energy required for this type of electrode ionization cell is less than 1 watt per liter of solution.

[0113] According to a variant of the invention, the chamber of the electrode ionization cell does not contain an ion exchanger filling, in which case the cell is operated as a pure electrodialysis cell, but the achievable residual conductivity is greater than in the case of a comparable electrode ionization cell containing an ion exchanger filling.

[0114] However, it is particularly preferred to provide an ion exchanger packing. The ion exchanger can for example consist of a mixed bed of anion and cation exchange resins, separated by a cation exchange membrane on the cathode side and by an anion exchange membrane on the anode side. The ion-depleted diluent stream flows through the packing. The ion exchange membrane is in contact with the concentrate stream on the opposite side of the ion exchange bed and at the same time with an electrode, between which an electric field is created. This variant offers the possibility of building multiple alternating diluent and concentrate chambers in order to facilitate a larger volumetric throughput with the same electrode surface area.

[0115] According to another variant, the diluent flows through the cation and anion exchange resins in two separate chambers. The cation exchange resin packing here is separated on the one hand from the concentrate flow by a cation exchange membrane and on the other hand from the anion exchange resin packing by a so-called bipolar membrane. In the bipolar membrane, protons are liberated on the cation exchange resin packing side and hydroxyl ions are liberated on the anion exchange resin packing side. The anion exchange resin packing itself is separated from the concentrate flow by an anion exchange membrane. EXAMPLES

[0116] The present invention will now be described with reference to the following examples, without however being limited thereto.

[0117] The coolant compositions were prepared by mixing the ingredients listed in Table 1 (all amounts are given in weight percent). The characteristics and physical parameters shown in Table 1 were determined as follows:

[0118] [Table 1]

[0119] Examples 2, 4, 5, and 6 are for comparative purposes, while examples 1, 3, 7, and 8 are according to the invention.

[0120] To ensure sufficient reserve alkalinity to buffer the acidic decomposition products of the coolant, the coolant was brought to a slightly alkaline pH value using various bases.

[0121] It can be easily seen that the use of strong bases potassium hydroxide and sodium hydroxide to achieve the target pH value (Comparative Examples 4 and 5) causes the conductivity to increase to unacceptably high values ​​due to their complete dissociation.

[0122] When diisopropylamine is used as base (Comparative Example 2), the conductivity decreases but still remains above the critical value of 50 μS / cm, which is reached only with the base (E) according to the invention (octyldiethanolamine in Example 3, preferably triethanolamine in Example 1).

[0123] Variation of the carboxylic acid shows that the use of the dicarboxylic acid sebacic acid (Comparative Example 6) leaves the conductivity above the critical value of 50 μS / cm. Good values ​​are obtained with the aromatic monocarboxylic acid benzoic acid (Example 8), and the aliphatic monocarboxylic acids ethylhexanoic acid (Example 7) and especially isononanoic acid (Example 1) are the most preferred.

[0124] [Table 2]

[0125] [Table 3]

[0126] Corrosion Examples The coolant composition of Example 1 and 0.01% by weight of a silicophosphonate (formula (V), R 5 = 1,3-propylene, R 6 , R 7 The composition of Example 1 further containing ethyl acetate (methyl and ethyl (statistical mixture), sodium salt) was compared in a corrosion test according to ASTM D1384 at 88°C.

[0127] The values ​​of pH, reserve alkalinity, conductivity and silicon content were determined before and after the corrosion test.

[0128] [Table 4]

[0129] The corrosion test results and pH values ​​are comparable within the accuracy of the measurements, but the decrease in reserve alkalinity and silicon content is less pronounced in the presence of silicophosphonate than in its absence.

[0130] Therefore, it is preferred that the coolant contain at least one silicophosphonate that reduces the consumption of tetraethoxysilane, which acts as an inhibitor of aluminum corrosion.

[0131] Application examples Application Example 1 (Comparison) A commercially available coolant containing monoethylene glycol, water, sebacic acid, adipic acid, sodium metasilicate, silicophosphonate, and tolutriazole, and exhibiting a conductivity of 4100 μS / cm, was used.

[0132] A Raspberry Pi4 computer with a USB-C power supply, a Micro HDMI port, a USB2 port, a USB3 port, a Gigabit Ethernet port, and 4 GB of RAM was connected to a power supply via the USB-C port and to an LCD flat screen via the Micro HDMI port. The Raspberry Pi4 program was started, transmitting a short film loop on the connected flat screen. The Raspberry Pi4 computer was then slowly submerged in a tank filled with the above coolant until the entire unit was submerged. Submersion was maintained for 5 minutes. During this time, the computer continued normal operation. The short film loop was displayed on the connected flat screen throughout, with no signs of malfunction or interference. The formation of deposits on the computer and the continued generation of gas were observed. The computer's control LEDs were operational. After the submersion period, the computer was removed from the fluid tank so as not to cause a short circuit, the access fluid was removed by pressurized air, and the computer was allowed to dry under ambient conditions. During this period and for the following 10 minutes of experimentation, the short film loop was displayed on the connected flat screen, with no signs of malfunction or interference. A visual inspection of the computer revealed deposits formed on various parts of the computer, primarily the connector pins.

[0133] Application Example 2 A commercially available coolant containing monoethylene glycol, water, tetraethoxysilane, and benzotriazole and exhibiting a conductivity of 1.2 μS / cm was used.

[0134] Application Example 1 was repeated using a coolant according to the invention. During (5 minutes) and after the soaking period (10 minutes), the computer continued to operate normally and no signs of malfunction or interference were observed.

[0135] No deposits were observed to form on the computer and no gas evolution was noted. Visual inspection of the computer revealed no changes. The connector pins remained clean and in pristine condition.

Claims

1. (A) at least one glycol (B) Water (C) at least one azole derivative (D) at least one ester of orthosilicic acid or alkoxyalkylsilane (E) optionally, at least one tertiary amine having at least one 2-hydroxyethyl or 2-hydroxypropyl group; (F) optionally at least one monocarboxylic acid (G) Optionally, at least one silicophosphonate (H) Optionally, at least one additional coolant additive Use of a coolant comprising: Components (C) through (H) are present in amounts such that the coolant exhibits a conductivity of less than 50 μS / cm, preferably less than 45 μS / cm; Use of a coolant for thermally managing a heat-generating electronic device, preferably an electronic device comprising a data center, more preferably an electronic device comprising a data center containing electronic components.

2. 10. A method for thermally managing a heat-generating electronic device, preferably an electronic device comprising a data center, more preferably an electronic device comprising a data center containing electronic components, by directly or indirectly contacting the heat-generating electronic device with the coolant of claim 1, conveying the coolant to a heat exchanger, and recirculating the coolant.

3. 3. The use and method of claim 1 or 2, wherein the glycol (A) is selected from the group consisting of monoethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, monopropylene glycol, dipropylene glycol, 1,3-propanediol, higher polyalkylene glycols, alkylene glycol ethers, and glycerol.

4. 3. The use and method according to claim 1 or 2, wherein the azole derivative (C) is selected from the group consisting of benzimidazole, benzotriazole, tolutriazole, hydrogenated tolutriazole, (2-benzothiazylthio)acetic acid, and (2-benzothiazylthio)propionic acid.

5. 3. The use and method according to claim 1 or 2, wherein the ester of orthosilicic acid (D) is orthosilicic acid tetraethyl ester or orthosilicic acid tetramethyl ester.

6. The tertiary amine (E) is Compounds of general formula (I) 【化1】 (In the formula, R ２ and R ３ are each, independently of one another, a linear or branched, preferably linear, alkyl substituent as described above, preferably having 1 to 18 carbon atoms, preferably 2 to 16, more preferably 4 to 14, particularly 6 to 12 carbon atoms, or may together form a 5- or 6-membered ring containing a nitrogen atom. X ｉ is -CH ２ -CH ２ —O—, —CH ２ -CH(CH ３ ) —O—, or —CH(CH ３ )-CH ２ -O-, preferably -CH ２ -CH ２ -O-, where n is a positive integer of 1 to 5, preferably 1 to 4, more preferably 1 to 3, even more preferably 1 or 2, and especially 1; Compounds of general formula (II) [Chemical Formula 2] (In the formula, R ４ is a linear or branched, preferably linear, alkyl substituent as defined above, preferably containing 1 to 18 carbon atoms, preferably 2 to 16, more preferably 4 to 14, especially 6 to 12 carbon atoms, Each Xi of i=1 to p and 1 to q is -CH ２ -CH ２ —O—, —CH ２ -CH(CH ３ ) —O—, or —CH(CH ３ )-CH ２ is independently selected from the group consisting of —O—, preferably —CH ２ -CH ２ -O-, and p and q are each independently a positive integer from 1 to 5, preferably from 1 to 4, more preferably from 1 to 3, even more preferably 1 or 2, in particular 1; - A tertiary amine having three 2-hydroxyethyl groups or 2-hydroxypropyl groups; The use and method according to claim 1 or 2, which is selected from the compounds.

7. The use and method according to claim 6, wherein the tertiary amine of the general formula (I) is selected from the group consisting of dimethylethanolamine, dimethylpropanolamine, diethylethanolamine, diethylpropanolamine, di-n-butylethanolamine, di-n-butylpropanolamine, N-hydroxyethylpyrrolidine, N-hydroxyethylpiperidine, and N-hydroxyethylmorpholine.

8. The tertiary amine of the general formula (I) has a substituent R ４ The use and method according to claim 6, wherein the tertiary amine of the general formula (I) is bis(2-hydroxyethyl)amine or bis(2-hydroxypropyl)amine having n-hexylamine, 2-methylpentylamine, n-heptylamine, 2-heptylamine, isoheptylamine, 1-methylhexylamine, n-octylamine, 2-ethylhexylamine, 2-aminooctane, 6-methyl-2-heptylamine, n-nonylamine, isononylamine, n-decylamine, and 2-propylheptylamine, or a mixture thereof as the substituent R

9. The use and method according to claim 6, wherein the tertiary amine having three 2-hydroxyethyl groups or 2-hydroxypropyl groups is selected from the group consisting of triethanolamine and tripropanolamine.

10. The use and method according to claim 1 or 2, wherein the monocarboxylic acid (F) is aliphatic, aromatic, or alicyclic, preferably aliphatic having 5 to 14 carbon atoms, preferably 6 to 12 carbon atoms.

11. The use and method according to claim 1 or 2, wherein the monocarboxylic acid (F) is linear or branched, preferably branched aliphatic.

12. The use and method according to claim 1 or 2, wherein the monocarboxylic acid (F) is selected from the group consisting of 2-ethylhexanoic acid and isononanoic acid.

13. The use and method according to claim 1 or 2, wherein there is no carboxylic acid having a functionality greater than 1.

14. The use and method according to claim 1 or 2, wherein both the tertiary amine (E) and the monocarboxylic acid (F) are present, and the molar ratio of the tertiary amine (E) to the monocarboxylic acid (F) is 1:0.1 to 1:0.

6.

15. The use and method according to claim 1 or 2, wherein neither the tertiary amine (E) nor the monocarboxylic acid (F) is present.

16. A system comprising at least one heat-generating electronic device that directly or indirectly contacts the coolant according to claim 1 or 2, wherein the coolant is recycled to at least one condenser or heat exchanger, preferably a heat exchanger that contacts a heat sink, within the thermal management system and recycled to the at least one heat-generating electronic device.

17. The system according to claim 16, wherein the at least one heat-generating electronic device is selected from the group consisting of a microprocessor, a wafer used in the manufacture of semiconductor devices, a power control semiconductor, a circuit board, a multi-chip module, a packaged or unpackaged semiconductor device, a semiconductor integrated circuit, a personal computer, a microprocessor, a server, a mobile phone, a personal digital assistant, and a data center.

18. The system according to claim 16, wherein the applied voltage does not exceed 60V.

Images