Novel use of coolants

Abstract

This invention relates to a novel use of coolant in a wind turbine cooling system.

Description

[Technical Field]

[0001] This invention relates to a preferred coolant for a wind turbine cooling system. [Background technology]

[0002] Automotive coolants have long been known and are used in automobiles, particularly to dissipate heat from internal combustion engines. Similarly, wind turbines release heat during operation, and this heat must be dissipated to protect their mechanical or electrical systems, such as the generator, gearbox, bearings, converter, and operating system, from overheating. Especially in the case of offshore wind turbines, maintenance and upkeep are far more complex and costly than those of automobiles, and therefore longer maintenance intervals are particularly desirable. In addition, wind turbines have different requirements for coolants compared to automobiles due to the different materials used in their cooling systems and the different operating conditions. For example, while automotive combustion engine coolants are exposed to higher wall temperatures and therefore higher thermal stress, wind turbines require a high level of corrosion resistance for the materials used and maintenance intervals of at least five years. Therefore, it is not possible to simply apply automotive coolants to the requirements of wind turbines.

[0003] European Patent Application Publication No. 3828411A1 describes a wind turbine and a method of operating it. It also mentions a coolant, which must be water, glycol, or a mixture thereof.

[0004] However, this type of coolant does not meet the above requirements for coolants used in wind turbines. European Patent Application Publication No. 3828411A1 makes no mention of coolants with respect to, for example, corrosion resistance, viscosity, stability, temperature resistance, or electrical conductivity.

[0005] According to available machine translations, Chinese Patent No. 109837071B describes a coolant for a wind turbine comprising ethylene glycol, an aliphatic monocarboxylic acid, an azole component, an antifoaming agent, and water, and a corrosion inhibitor mixture comprising alkoxylated acetylene alcohol and imidazoline as a corrosion inhibitor. The electrical conductivity of the coolant described herein is less than 200 μS / cm.

[0006] A drawback of these coolants is that achieving the required low electrical conductivity necessitates the use of the described corrosion inhibitor mixture, which is not commercially available and therefore increases the cost of the coolant. Furthermore, only aliphatic monocarboxylic acids are described as additional corrosion inhibitors. [Overview of the project] [Problems that the invention aims to solve]

[0007] Therefore, the object of the present invention is to provide a coolant that satisfies the specific requirements profile of a wind turbine and its operational specificities. [Means for solving the problem]

[0008] The purpose of this is, - At least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol, preferably monoethylene glycol, - Optionally, at least one organic mono or dicarboxylic acid, preferably an aliphatic mono or dicarboxylic acid, - At least one inorganic salt selected optionally from the group consisting of molybdate, borate, phosphate, silicate, nitrite, and nitrate, - At least one azole compound, - Water and, - Optionally, at least one silicate ester, - Optionally, if silicates are present, at least one silicophosphonate, - Optionally, further inhibitors and typical coolant components are included, provided that at least one mono- or dicarboxylic acid and / or at least one inorganic salt is present in the coolant, in a cooling system of a wind turbine, preferably, - a generator, - a gearbox, - a bearing, - a converter, and - an operating system is achieved by using in a cooling system for thermal management of at least one component of a wind turbine selected from the group consisting of.

Mode for Carrying Out the Invention

[0009] These coolants, particularly the embodiments listed below, meet the requirements and show a sufficient corrosion inhibition effect on the cooling system used and sufficient stability of the coolant components present, as a result, the durability of the coolant is improved, and thus the maintenance interval is lengthened. The upper limit of the electrical conductivity of 200 μS / cm defined in the Chinese Patent No. 109837071B is not absolutely necessary for the coolant and can be waived for the benefit of increasing the content of the corrosion inhibitor, and it has been found that this ensures the corrosion inhibition effect over the long operating hours required in a wind turbine.

[0010] In particular, the present invention does not require the corrosion inhibitor composition of Chinese Patent No. 109837071B containing alkoxylated acetylene alcohol and imidazoline corrosion inhibitor, particularly propynol alkoxylate, butynediol alkoxylate and octynol alkoxylate as alkoxylated acetylene alcohol, and carboxyethyl imidazoline, heptadecenylamine ethyl imidazoline and heptadecenylamine ethyl imidazoline quaternary ammonium salt. The present invention excludes the presence of a combination of alkoxylated acetylene alcohol and a corrosion inhibitor having an imidazoline structure in the coolant according to the present invention.

[0011] Since aluminum is a widely used material in the cooling systems of wind turbines, suppressing aluminum corrosion at a high level is one specific requirement.

[0012] The components of the coolant are explained below:

[0013] Freezing point depressing component This component has a major freezing point depression effect in coolants. It includes monomer to tetramer 1,2-ethylene glycol, 1,2-propylene glycol, or, less commonly, 1,3-propylene glycol, preferably monomer to trimer 1,2-ethylene glycol or 1,2-propylene glycol, more preferably monomer or dimer 1,2-ethylene glycol, most preferably monomer 1,2-ethylene glycol (monoethylene glycol), and in any case, mixtures thereof.

[0014] The alkylene glycol monoalkyl ether is a mono C1-C4 alkyl ether of the alkylene glycol described above, preferably monomethyl, ethyl, or n-butyl ether, more preferably monomethyl or n-butyl ether, and most preferably monomethyl ether.

[0015] In addition, glycerol or glycerol oligomers are potential freezing point depressants.

[0016] Preferred alkylene glycol components or derivatives are, in particular, monoethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and mixtures thereof, but also monopropylene glycol, dipropylene glycol, and mixtures thereof. Polyglycols, 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, can be used individually or as mixtures thereof.

[0017] Particularly preferred is the use of monoethylene glycol alone, or a mixture of monoethylene glycol as a main component, i.e., in a mixture containing more than 50% by weight, especially more than 80% by weight, specifically more than 95% by weight, and other alkylene glycols or alkylene glycol derivatives.

[0018] In a particularly preferred embodiment, the freezing point depression component consists of monoethylene glycol, but the monoethylene glycol may contain other alkylene glycol components from the above in an amount of up to 5% by weight, preferably up to 3% by weight, and more preferably up to 2% by weight, for the purpose of its preparation.

[0019] Monoethylene glycol contains small amounts of higher homologues, particularly diethylene glycol, triethylene glycol, and tetraethylene glycol, for its preparation method. The total content is generally up to 10% by weight, preferably up to 7.5% by weight, and most preferably up to 5% by weight. The homologues generally decrease in proportion to the increase in molar weight.

[0020] In a preferred embodiment of the present invention, monoethylene glycol derived at least partially, preferably completely, from the treatment of a used aqueous coolant is used as the coolant.

[0021] For this purpose, used aqueous coolants, preferably from automobiles and / or stationary motors or generators, are first collected in a decentralized manner, preferably from workshops and / or maintenance companies. - The used aqueous coolants thus collected are gathered, mixed, and transported to a central location where these used glycol-containing coolants are subjected to a purification process, preferably at least one distillation.

[0022] Preferably, the purification process described in the unpublished European Patent Application No. 23214551.6, filed on December 6, 2023, wherein the aqueous glycol-containing coolant used is at least: (a) A step of removing components with a lower boiling point than glycol by distillation, (b) The step of distilling glycol and Including, and further, (c) Step of stripping the glycol-containing mixture with a gas, preferably an inert gas, (d) A step of treating the glycol-containing mixture with an acidic or basic, preferably basic, solid, (e) a step of treating a glycol-containing mixture with activated carbon, and / or (f) Step of subjecting the glycol-containing mixture to membrane filtration. It is subjected to a purification process that includes at least one of the following steps.

[0023] Each process step is described in detail in European Patent Application No. 23214551.6.

[0024] The processed monoethylene glycol is referred to herein as recycled monoethylene glycol.

[0025] In preferred embodiments, the monoethylene glycol used as a coolant for use according to the present invention comprises at least 33% by weight, more preferably at least 50% by weight, even more preferably at least 66% by weight, particularly at least 75% by weight, and specifically at least 90% by weight of recycled monoethylene glycol. In particular embodiments, the monoethylene glycol used is entirely recycled monoethylene glycol. In a more preferred embodiment of the present invention, monoethylene glycol derived at least partially, preferably entirely, from renewable raw materials is used as a coolant.

[0026] Monoethylene glycol obtained from renewable raw materials is preferably processed according to ASTM D6866 ("Determining the Biobased Content of Natural Range Materials Using Radiocarbon and Isotope Ratio Mass Spectrometry Analysis") 14 C / 12 It can be characterized by determining the 1C isotope ratio. According to this test method, the sample 14 C / 12 The 14C isotope ratio was measured in standardized 100% bio-based materials. 14 C / 12 The results are compared with the 1C isotope ratio. The obtained results represent the level of biobase content in the sample.

[0027] The application of ASTM-D6866 to derive "biobase content" is based on the same concept as radiocarbon dating, but does not use an age equation. The analysis involves radiocarbon in an unknown sample. 14It is carried out by determining the ratio of the amount of (C) compared to that of the modern reference standard. This index is expressed as a percentage using the unit "pMC" (percent modern carbon). When the material being analyzed is a mixture of modern radiocarbon and fossil carbon (which has a very low radiocarbon content), the resulting pMC value is directly correlated with the amount of biomass material present in the sample.

[0028] The monoethylene glycol used in the coolant according to the present invention preferably has a 14 C: 12 bio - based content measured as a C:C ratio greater than 0%, preferably at least 1%, more preferably at least 5%, even more preferably at least 10%, particularly at least 20%, specifically at least 25%.

[0029] Advantageously, this bio - based content can be at least 30%, preferably at least 40%, more preferably at least 50%, even more preferably at least 66%, particularly at least 75%, specifically at least 85%.

[0030] In the case of a content of at least 90%, preferably at least 95%, more preferably at least 98%, and further 100%, this can be referred to as monoethylene glycol that is clearly predominantly or completely bio - based.

[0031] For example, this monoethylene glycol that is bio - based or obtained from renewable raw materials can be obtained by the process described in the unpublished European patent application No. 23185804.4 filed on July 17, 2023. The said application describes a process by which bio - based monoethylene glycol can be obtained from various sources.

[0032] The use of bio-based monoethylene glycol, at least partially, can preferably reduce emissions from the use of alkylene glycol-containing coolants, such as emissions of nitrogen oxides and sulfur oxides, and especially carbon dioxide, as determined in terms of carbon footprint, life cycle assessment, or according to DIN EN ISO 14021, DIN EN ISO 14067, particularly in this case the 2019-02 edition, DIN EN ISO 14044, particularly in this case the 2006+A1:2018 edition, and / or DIN EN ISO 14040, particularly in this case the 2009-11 edition.

[0033] Organic mono- or dicarboxylic acids Organic carboxylic acids are often used as corrosion inhibitors to combat the corrosion of steel materials. Examples of steel materials include steel, wrought iron, or cast iron.

[0034] The organic mono and dicarboxylic acids may be aromatic or aliphatic carboxylic acids, preferably aromatic monocarboxylic acids and aliphatic mono and dicarboxylic acids, more preferably aliphatic mono and dicarboxylic acids.

[0035] A preferred aromatic monocarboxylic acid is benzoic acid, which can be used in the form of a free acid, or more preferably in the form of an alkali metal salt thereof, and most preferably in the form of sodium benzoate.

[0036] Preferred monocarboxylic acids are organoaliphatic alkanes or alkenecarboxylic acids. Provided they have sufficient water solubility, these are often used in coolants as corrosion inhibitors to combat the corrosion of steel materials.

[0037] Typical monocarboxylic acids of this type include pentanoic acid, 2,2-dimethylpropanoic acid, hexanoic acid, 2,2-dimethylbutanoic acid, octanoic acid, 2-ethylhexanoic acid, nonanoic acid, isononanoic acid, decanoic acid, undecanoic acid, and dodecanoic acid, as well as mixtures of their isomers, particularly mixtures of isomers of 2-ethylhexanoic acid and isononanoic acid.

[0038] Examples of branched-chain aliphatic monocarboxylic acids include 2-ethylhexanoic acid, 2,2-dimethylhexanoic acid (neooctanoic acid, versatic acid 8), 2,2-dimethylheptanoic acid (neononanoic acid, versatic acid 9), isononanoic acid, 2-propylheptanoic acid, 2,2-dimethyloctanoic acid (neodecanoic acid, versatic acid 10), neoundecanoic acid (versatic acid 11), neododecanoic acid, and neotridecanoic acid (versatic acid 13).

[0039] For health reasons, the use of 2-ethylhexanoic acid is sometimes undesirable. Preferably, the 2-ethylhexanoic acid content in the coolant is less than 3%, more preferably less than 0.3%, and most preferably, the coolant contains no 2-ethylhexanoic acid at all.

[0040] In one embodiment, the content of 2-ethylhexanoic acid in the coolant is reduced or avoided by completely, partially, preferably completely replacing 2-ethylhexanoic acid with at least one aliphatic monocarboxylic acid other than 2-ethylhexanoic acid, particularly isononanoic acid, from the above. In a preferred embodiment, 2-ethylhexanoic acid may be partially replaced by a combination of 2-ethylhexanoic acid and benzoic acid.

[0041] In preferred embodiments, 2-ethylhexanoic acid may be completely or partially replaced by a combination of 2-ethylhexanoic acid and at least one aliphatic dicarboxylic acid from the above, particularly preferably a combination of 2-ethylhexanoic acid and adipic acid, or a combination of 2-ethylhexanoic acid and sebacic acid.

[0042] Particularly preferred is the use of a mixture of at least two aliphatic dicarboxylic acids, such as a mixture of adipic acid and sebacic acid, instead of using 2-ethylhexanoic acid.

[0043] Therefore, in a preferred embodiment, the coolant used is at least one dicarboxylic acid, preferably at least one aliphatic dicarboxylic acid, in the absence of an aliphatic monocarboxylic acid. This is particularly preferred when at least one inorganic salt is not present at the same time. When at least one inorganic salt is not present, it is possible to use a combination of at least one dicarboxylic acid, preferably at least one aliphatic dicarboxylic acid, and at least one monocarboxylic acid, preferably at least one aliphatic monocarboxylic acid, and it is particularly preferred here to use at least one dicarboxylic acid, preferably at least one aliphatic dicarboxylic acid, without the simultaneous presence of an aliphatic monocarboxylic acid.

[0044] Compared to aliphatic monocarboxylic acids, the advantage of dicarboxylic acids, especially aliphatic dicarboxylic acids, is that in corrosion tests of various materials such as iron, steel, copper, brass, and aluminum, they can form chelate complexes with metal ions and thus stabilize the metal ions in solution. As a result, they do not precipitate and form coatings that reduce heat transfer in the cooling system or clog conduits in the coolant circuit. In the case of dicarboxylic acids, the presence of two carboxylic acid groups allows for the formation of stronger chelate complexes with metal ions than in the case of monocarboxylic acids. Furthermore, these chelate complexes are effective in suppressing further corrosion by preventing metal ions from reacting with the environment to form corrosion products. In addition, dicarboxylic acids are less volatile than monocarboxylic acids, meaning they remain in the coolant even at relatively high temperatures, such as under the conditions of a cooling circuit. Moreover, aliphatic monocarboxylic acids have a hydrophilic end due to a carboxyl or carboxylate group and a hydrophobic end due to an aliphatic alkyl radical, and the solubility of aliphatic monocarboxylic acids in the coolant can be limited by the hydrophobic effect of the long alkyl radical. In contrast, in the case of dicarboxylic acids, particularly aliphatic dicarboxylic acids, and especially the particularly preferred aliphatic α,ω-dicarboxylic acids, the relationship between the hydrophilic carboxyl group and the hydrophobic bond chain is such that the hydrophilic influence prevails. One reason for this is that the ratio of carbon atoms in the carboxyl group to carbon atoms in the aliphatic alkylene chain is favorable for hydrophilic properties, and another reason is that, instead of hydrophilic and hydrophobic ends being formed as in aliphatic monocarboxylic acids, the hydrophobic chain is surrounded at its ends by hydrophilic carboxyl groups.

[0045] Similarly, particularly preferred is a mixture of 2-ethylhexanoic acid and at least one inorganic salt selected from the group consisting of molybdate, borate, phosphate, silicate, and nitrate, and most preferred is a mixture of 2-ethylhexanoic acid and at least one inorganic salt selected from the group consisting of molybdate, phosphate, and silicate.

[0046] Neoalkanecarboxylic acids, which have 8 to 13 carbon atoms, may be mixtures of isomers and are not necessarily pure isomers.

[0047] For example, neodecanoic acid is a mixture of carboxylic acids containing 2,2,3,5-tetramethylhexanoic acid, 2,4-dimethyl-2-isopropylpentanoic acid, 2,5-dimethyl-2-ethylhexanoic acid, 2,2-dimethyloctanoic acid and / or 2,2-diethylhexanoic acid (CAS 26896-20-8).

[0048] In preferred embodiments, the aliphatic carboxylic acid is isononanoic acid. In relation to this specification, this refers to one or more branched aliphatic carboxylic acids having nine carbon atoms. One embodiment of isononanoic acid may include 7-methyloctanoic acid (e.g., CAS numbers 693-19-6 and 26896-18-4), 6,6-dimethylheptanoic acid (e.g., CAS number 15898-92-7), 3,5,5-trimethylhexanoic acid (e.g., CAS number 3302-10-1), 3,4,5-trimethylhexanoic acid, 2,5,5-trimethylhexanoic acid, 2,2,4,4-tetramethylpentanoic acid (e.g., CAS number 3302-12-3), and mixtures thereof. In preferred embodiments, the isononanoic acid contains, as a major component exceeding 90% (in total), at least one carboxylic acid selected from the group consisting 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. The remaining proportion to constitute 100% may consist of other carboxylic acids having nine carbon atoms and small amounts of by-products. In preferred embodiments, the isononanoic acid contains, as a major component, at least 90%, preferably at least 95%, of 3,5,5-trimethylhexanoic acid.

[0049] The organic dicarboxylic acid having 4 to 20 carbon atoms is a linear or branched alkanedicarboxylic acid, preferably a linear alkane or alkenedicarboxylic acid, more preferably an alkanedicarboxylic acid, more preferably having 5 to 14 carbon atoms, and most preferably having 6 to 12 carbon atoms.

[0050] Aliphatic dicarboxylic acids are preferably succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, pimelic acid (heptanediic acid), azelaic acid (nonanediic acid), sebacic acid (decanediic acid), undecanediic acid, dodecanediic acid, and alkyl and alkenyl succinic acid and glutaric acid, for example, 2-methylbutanediic acid, 2-ethyl-3-methylbutanediic acid, 2-ethylpentanediic acid, 2-dodecylbutanediic acid, 2- The following are selected from the group consisting of dodecenylbutanediic acid, 2-phenylbutanediic acid, 2-(p-methylphenyl)butanediic acid, 2,2-dimethylbutanediic acid, 2,3,4-trimethylpentanediic acid, 2,2,3-trimethylpentanediic acid, glutaconic acid (penta-2-enedioic acid), itaconic acid, hexa-2-enedioic acid, hexa-3-enedioic acid, 5-methylhexa-2-enedioic acid, and 2,3-dimethylpenta-2-enedioic acid.

[0051] Among these, dicarboxylic acids having 6 to 12 carbon atoms are preferred, alkanedicarboxylic acids having 6 to 12 carbon atoms are particularly preferred, and linear alkanedicarboxylic acids having 6 to 12 carbon atoms are very preferred.

[0052] Particularly preferred aliphatic dicarboxylic acids are adipic acid, sebacic acid, azelaic acid, and dodecanedicarboxylic acid, in particular adipic acid, sebacic acid, and dodecanediic acid, and especially adipic acid and sebacic acid.

[0053] inorganic salts Inorganic salts are often used as corrosion inhibitors to combat the corrosion of iron and / or aluminum-containing materials and solder.

[0054] At least one inorganic salt is selected from the group consisting of molybdate, borate, phosphate, silicate, nitrite, and nitrate, preferably from the group consisting of borate, phosphate, silicate, nitrite, and nitrate, and more preferably from the group consisting of phosphate, silicate, and nitrate.

[0055] Inorganic inhibitors are phosphates, silicates, borates, nitrites, nitrates, or molybdates, or mixtures thereof, in the form of their free acid or salt, particularly their alkali metal salt, more preferably their sodium or potassium salt, or mixtures thereof. Their form (protonated or salted form) in compositions, superconcentrates, concentrates, or coolants depends on the specific pK of the compound and composition. a It is determined by the pH of a specific medium, which is established by the amount of base.

[0056] Molybdates are used in the form of free acid (H2MoO4), hydrogen molybdate, or preferably molybdate salts, particularly alkali metal salts, more preferably sodium or potassium salts, most preferably sodium salts. Acidic protons in molybdates can be partially or completely substituted by alkali metal salts. Preferably, sodium molybdate is used, usually in dihydrate form.

[0057] The borate is preferably used in the form of sodium tetraborate (borax) or potassium tetraborate, and more preferably in the form of sodium tetraborate.

[0058] Phosphates are used in the form of free acid (H3PO4), or in the form of hydrogen phosphate, dihydrogen phosphate, or phosphate, particularly in the form of alkali metal salts, more preferably sodium or potassium salts. Acidic protons in phosphates can be partially or completely substituted by alkali metal salts.

[0059] While it is also possible to use corresponding diphosphates, triphosphates, or oligophosphates, or mixtures thereof with monophosphates, these are preferably used in the form of monomeric phosphates.

[0060] Preferably, free acid (H3PO4), disodium hydrogen phosphate, or trisodium phosphate is used.

[0061] Inorganic silicates primarily act as corrosion inhibitors for aluminum and aluminum-containing materials, as well as solder, and are usually used in the form of alkali metal salts, or less commonly, in the form of magnesium, calcium, or aluminum salts, preferably in the form of sodium or potassium salts.

[0062] The silicate is preferably orthosilicate (SiO4 4- ), metasilicate (SiO3 2- ), and pyrosilicate (Si2O7 6- Selected from the group consisting of ), more preferably metasilicate (SiO3 2- ), more preferably sodium metasilicate (Na2SiO3) or potassium metasilicate (K2SiO3), particularly sodium metasilicate (Na2SiO3).

[0063] Nitrites are all nitrite anions (NO2 - These are inorganic salts of sodium nitrite and nitrite (HNO2). Typically, nitrites are used in coolants in the form of sodium nitrite or potassium nitrite, or converted to them by an inorganic base, preferably sodium hydroxide or potassium hydroxide.

[0064] In preferred embodiments, the coolant does not contain nitrites for health reasons.

[0065] Nitrates are used in the form of alkali metal or alkaline earth metal nitrates, preferably sodium nitrate, potassium nitrate, or magnesium nitrate, preferably sodium nitrate or potassium nitrate, and more preferably sodium nitrate.

[0066] Preferred inorganic salts are selected from the group consisting of molybdates, borates, phosphates, silicates, and nitrates; more preferably selected from the group consisting of molybdates, borates, phosphates, and silicates; and most preferably selected from the group consisting of molybdates, phosphates, and silicates.

[0067] Azole compounds Azole compounds are particularly effective as corrosion inhibitors to combat the corrosion of non-ferrous metals, such as brass or copper.

[0068] In relation to this specification, an azole compound or azole derivative is understood to mean a five-membered heterocyclic compound having two or three heteroatoms from the group of nitrogen and sulfur, which may contain no sulfur atoms incorporated into the ring or at most one sulfur atom, and which may optionally have an aromatic or saturated six-membered condensation.

[0069] These five-membered heterocyclic compounds (azole derivatives) typically contain two nitrogen atoms as heteroatoms and no sulfur atoms, or three nitrogen atoms and no sulfur atoms, or one nitrogen atom and one sulfur atom.

[0070] The preferred group of azole derivatives mentioned is the following general formula [ka] These are condensed imidazoles and condensed 1,2,3-triazoles, where the variable R is hydrogen or C1-C 10 The alkyl radical is specifically methyl or ethyl, and the variable X is either a nitrogen atom or a CH moiety.

[0071] Typical and preferred examples of azole derivatives of general formula (III) are benzimidazole (X=CH, R=H), benzotriazole (X=N, R=H), and tolyltriazole (X=N, R=CH3). A typical example of an azole derivative of general formula (IV) is hydrogenated 1,2,3-tolyltriazole (X=N, R=CH3).

[0072] A further preferred group of azole derivatives mentioned is the general formula (V) [ka] The group of benzothiazoles, in the formula, The variable R has the above definition, The variable R' represents hydrogen, C1~C 10 The alkyl radical is specifically a methyl or ethyl group, or specifically a mercapto group (-SH). Less preferable, perhaps R' is also of formula -(C m H 2m It may also be a carboxyalkyl radical of the form )-COOR'', where m is a number from 1 to 4, and R'' is hydrogen, or C1 to C 10 Alkyl, specifically methyl or ethyl, or C6-C 12 These are aryl compounds. Examples include (2-benzothiadylthio)acetic acid, (2-benzothiadylthio)acetic acid ester, 3-(2-benzothiadylthio)propionic acid, or 3-(2-benzothiadylthio)propionic acid ester. When used in acidic form, these compounds do not form any of the carboxylic acids excluded according to the present invention. A typical example of an azole derivative of general formula (V) is 2-mercaptobenzothiazole.

[0073] General formula (VI) [ka] Non-condensed azole derivatives are also preferred, where the variables X and Y are both two nitrogen atoms, or These are nitrogen atoms and CH moieties, For example, 1H-1,2,4-triazole (X=Y=N), or preferably imidazole (X=N, Y=CH).

[0074] The most particularly preferred azole derivatives of the present invention are benzimidazole, benzotriazole, toltriazole, hydrogenated toltriazole, or mixtures thereof, specifically benzotriazole or toltriazole, and especially toltriazole.

[0075] The azole derivatives mentioned are commercially available or can be produced by general law. Hydrogenated benzotriazoles, such as hydrogenated toltriazole, are similarly available and commercially available in accordance with German Patent Application Publication (DE-A) No. 1948794.

[0076] The azole is preferably selected from the group consisting of benzotriazole, toltriazole, (2-benzothiadylthio)acetic acid, 3-(2-benzothiadylthio)propionic acid, and 2-mercaptobenzothiazole.

[0077] water The water used in relation to this invention should be neutral with a pH of 7. This may be demineralized water or distilled water, but is not necessarily required. To allow the use of hard water, at least one hard water stabilizer may be added to the coolant composition.

[0078] The water used may contain alkaline earth metal ions, such as magnesium, calcium, strontium, or barium ions, the latter usually present in trace amounts at most. Preferably, essentially only magnesium and / or calcium ions are present as the curing agent.

[0079] The water used is preferably soft water with a water hardness of 8.4°dH or less, more preferably 10°dH or less, and most preferably 12°dH or less.

[0080] When water with a water hardness of up to 14°dH, preferably up to 17°dH, more preferably up to 20°dH, and even more preferably up to 25°dH is used, a hard water stabilizer is generally required.

[0081] For curing agents, the water used as a coolant is a common source of carbonates and / or sulfates present in the coolant.

[0082] Silicate esters In place of or in addition to the inorganic silicates described, the coolant may also include organic orthosilicate esters of general formula Si(OR)4, where each R is independently a C1-C4 alkyl, preferably methyl, ethyl, or n-butyl, particularly preferably methyl or ethyl, or a mixture of methyl and ethyl.

[0083] Orthosilicate esters primarily act as corrosion inhibitors for aluminum or aluminum-containing materials and solder.

[0084] Silicophosphonate If the composition contains at least one inorganic silicate, in a preferred embodiment, at least one silicophosphonate is added in addition to the silicate, as described in European Patent Application EP4015596.

[0085] Silicophosphonates are preferably of the following general formula [ka] It is a compound of the formula, in which, R 5 This is a divalent organic radical, preferably a 1,ω-alkylene group having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, more preferably methylene, 1,2-ethylene, 1,2-propylene, 1,3-propylene, or 1,4-butylene, even more preferably 1,2-ethylene or 1,3-propylene, and particularly 1,2-ethylene. R 6 These are independently hydrogen, C1-C4 alkyl, or hydroxy-C2-C4 alkyl, preferably hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or tert-butyl, 2-hydroxyethyl, or 2-hydroxypropyl, more preferably hydrogen, methyl, ethyl, or propyl. R 7 The C1-C4 alkyl group is preferably methyl, ethyl, n-propyl, or n-butyl, more preferably methyl, ethyl, or n-butyl, even more preferably methyl or ethyl, and particularly methyl.

[0086] Silicophosphonates can be used in the form of free acids or as alkali metal salts, preferably as sodium salts or potassium salts, more preferably as sodium salts.

[0087] Further inhibitors and typical coolant components As further conventional auxiliary agents, the coolant may optionally include a small amount of conventionally used defoaming agent (generally 0.003% to 0.008% by weight in the diluted coolant), as well as a bittering agent (e.g., of the denatonium benzoate type) and a dye, for reasons of hygiene and safety in case of ingestion.

[0088] Furthermore, the composition may contain one or more hard water stabilizers based on polyacrylic acid, polymaleic acid, acrylic acid-maleic acid copolymer, polyvinylpyrrolidone, polyvinylimidazole, vinylpyrrolidone-vinylimidazole copolymer, and / or copolymers of unsaturated carboxylic acids and olefins. The proportions in the composition are selected so that, after appropriate dilution, the amount in the diluted coolant is a maximum of 1% by weight.

[0089] In a preferred embodiment, a hard water stabilizer described in International Publication No. 2022 / 200155 is used. The advantage of using hard water stabilizers is that there is no need to use desalinated or distilled water to reduce or prevent the precipitation of alkaline earth metal compounds.

[0090] Coolant composition Coolants suitable for use in wind turbines are preferably prepared by diluting a concentrate (see below) with water, for example, with the following composition: - 40% to 75% by weight, preferably 45% to 70% by weight, more preferably 50% to 70% by weight, even more preferably 55% to 67.5% by weight, especially 60% to 65% by weight of water, - 20% to 55% by weight, preferably 25% to 50% by weight, more preferably 25% to 45% by weight, even more preferably 30% to 50% by weight, and especially at least 32.5% to 35% by weight of alkylene glycol, alkylene glycol monoalkyl ether and glycerol, - The following components in total, in an amount of 0.1% to 5% by weight, preferably 0.25% to 4.5% by weight, more preferably 0.5% to 4% by weight, and especially 1% to 4% by weight: -- Optionally, at least one organic mono or dicarboxylic acid, preferably an aliphatic mono or dicarboxylic acid, -- At least one inorganic salt selected optionally from the group consisting of molybdate, borate, phosphate, silicate, nitrite, and nitrate, -- At least one azole compound, -- Optionally, at least one silicate ester, --Optionally, if silicates are present, at least one silicophosphonate, - Optionally, a further inhibitor and typical coolant component in an amount of 0% to a maximum of 1% by weight, preferably 0% to a maximum of 0.75% by weight, more preferably 0.05% to 0.5% by weight, even more preferably 0.1% to 0.4% by weight, and especially 0.2% to 0.3% by weight. It has, However, provided that at least one mono- or dicarboxylic acid and / or at least one inorganic salt is present in the coolant, The sum of all components must always equal 100% by weight.

[0091] In a preferred embodiment, the coolant is - At least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol, preferably monoethylene glycol, - At least one aromatic organic monocarboxylic acid, - At least one inorganic salt selected from the group consisting of molybdate, borate, phosphate, silicate, nitrite, and nitrate, - At least one azole compound, - Water and, - Optionally, if silicates are present, at least one silicophosphonate, preferably, if silicates are present, at least one silicophosphonate and - Optionally, hard water stabilizers, bittering agents, defoaming agents and / or dyes Includes.

[0092] In a similarly preferred embodiment, the coolant is - At least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol, preferably monoethylene glycol, - At least one organic mono or dicarboxylic acid, preferably an aliphatic mono or dicarboxylic acid, more preferably at least one aliphatic monocarboxylic acid and at least one aliphatic dicarboxylic acid, or more preferably at least two aliphatic dicarboxylic acids, particularly without using 2-ethylhexanoic acid, at least two aliphatic dicarboxylic acids, specifically without using a monocarboxylic acid, - At least one azole compound, - Water and, - Optionally, hard water stabilizers, bittering agents, defoaming agents and / or dyes Includes, However, this is conditional on the absence of inorganic salts selected from the group consisting of molybdate, borate, phosphate, silicate, nitrite, and nitrate in the coolant.

[0093] In a similarly preferred embodiment, the coolant is - At least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol, preferably monoethylene glycol, - At least one organic mono or dicarboxylic acid, preferably an aliphatic mono or dicarboxylic acid, more preferably at least one aliphatic monocarboxylic acid and at least one aliphatic dicarboxylic acid, - At least one inorganic salt selected from the group consisting of borates, phosphates, silicates, nitrites, and nitrates, - At least one azole compound, - Water and, - Optionally, hard water stabilizers, bittering agents, defoaming agents and / or dyes Includes.

[0094] In a similarly preferred embodiment, the coolant is - At least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol, preferably monoethylene glycol, - At least one organic mono or dicarboxylic acid, preferably an aliphatic mono or dicarboxylic acid, more preferably at least one aliphatic monocarboxylic acid and at least one aliphatic dicarboxylic acid, or more preferably at least two aliphatic dicarboxylic acids, - At least one inorganic salt selected from the group consisting of molybdate, borate, phosphate, silicate and nitrate, preferably selected from the group consisting of phosphate and silicate, - At least one azole compound, - Water and, -Optionally, if silicates are present, at least one silicophosphonate, preferably, if silicates are present, at least one silicophosphonate, - Optionally, hard water stabilizers, bittering agents, defoaming agents and / or dyes Includes.

[0095] In the last two embodiments mentioned, the inorganic salt preferably comprises at least one silicate, and more preferably, no other inorganic salts other than silicates are present.

[0096] In the above embodiments, the azole compound is preferably benzotriazole or toltriazole.

[0097] The non-aliphatic organic monocarboxylic acid is preferably benzoic acid.

[0098] The aliphatic monocarboxylic acid is preferably selected from the group consisting of 2-ethylhexanoic acid and isononanoic acid, more preferably isononanoic acid.

[0099] The aliphatic dicarboxylic acid is preferably selected from the group consisting of adipic acid, sebacic acid, and dodecanediic acid.

[0100] The inorganic salt is preferably selected from the group consisting of molybdate, borate, phosphate, and silicate, more preferably from the group consisting of molybdate, phosphate, and silicate, and most preferably from the group consisting of phosphate and silicate.

[0101] At a temperature of 20°C, the coolant should be 3 mm in size according to ASTM D445. 2 The kinematic viscosity must not exceed 2.5 mm / second, preferably 2.5 mm 2 Less than / second, more preferably 2mm 2 Less than / second, and more preferably 1.5mm 2 Less than / second, especially 1mm 2 It is less than / second.

[0102] At a temperature of 0°C, the coolant should be 7.5 mm in size according to ASTM D445. 2 The kinematic viscosity must not exceed 7 mm / second, preferably 7 mm 2 Less than / second, more preferably 6mm 2 Less than / second, and more preferably 5.5mm 2 Less than / second, especially 5mm 2 It is less than / second.

[0103] At a temperature of 80°C, the coolant is 1 mm thick according to ASTM D445. 2 The kinematic viscosity must not exceed 0.9 mm / second, preferably 0.9 mm2 Less than or equal to / second, more preferably 0.8mm 2 Less than / second, more preferably 0.7mm 2 Less than / second, especially 0.6mm 2 It is less than / second.

[0104] To reduce the volume to be transported, the products sold are typically concentrates with the water content removed or significantly reduced. The coolant is then prepared from the concentrate by adding water before filling it into the wind turbine. These concentrates are typically diluted with water in a volume ratio of 1:1 to 1:3 (volume / volume), preferably 1:1 to 1:2, depending on the general temperature and freeze protection requirements at the site.

[0105] Therefore, the concentrate has the same composition as the coolant described above, but the water content is reduced according to the dilution ratio. Generally, the water content in the concentrate is 15% by weight or less, preferably 10% by weight or less, and more preferably 5% by weight or less.

[0106] For example, the concentrate has the following composition: - 0.1% to 15% by weight of water, - 50% to 95% by weight of alkylene glycol, alkylene glycol monoalkyl ether, and glycerol, - The following ingredients in total, ranging from 0.5% to 15% by weight: -- Optionally, at least one organic mono or dicarboxylic acid, preferably an aliphatic mono or dicarboxylic acid, -- At least one inorganic salt selected optionally from the group consisting of molybdate, borate, phosphate, silicate, nitrite, and nitrate, -- At least one azole compound, -- Optionally, at least one silicate ester, - Optionally, if silicates are present, at least one silicophosphonate, - Optionally, 0% to a maximum of 3% by weight of further inhibitors and typical coolant components It has, In coolants, the combination of alkoxylated acetylene alcohol and a corrosion inhibitor having an imidazoline structure is excluded, However, provided that at least one mono- or dicarboxylic acid and / or at least one inorganic salt is present in the coolant, If at least one inorganic salt is not present, a further condition is that at least one dicarboxylic acid, preferably at least one aliphatic dicarboxylic acid, is present in the coolant. The sum of all components must always equal 100% by weight.

[0107] The pH of coolants prepared by end users is typically in the range of 4 to 11.5, preferably 5 to 10, and particularly 6 to 9.

[0108] In a method for preparing a coolant from a concentrated precoolant, the pH is established by adding at least one inorganic base at any stage. The at least one inorganic base may be present in the coolant or concentrate, or it may be added by mixing it with water when preparing the coolant from the concentrate. The preferred inorganic base is an alkali metal hydroxide, more preferably solid lithium hydroxide, sodium hydroxide, or potassium hydroxide, and optionally in the form of an aqueous solution of lithium hydroxide, sodium hydroxide, or potassium hydroxide.

[0109] Lithium, sodium, or potassium carbonates or bicarbonates are not very desirable.

[0110] Preferred alkali metals are sodium and potassium. According to the present invention, the electrical conductivity of the coolant is not very important and can be up to 3000 μS / cm (measured at 25°C according to ASTM D1125), preferably up to 2500 μS / cm, more preferably up to 2000 μS / cm, even more preferably up to 1500 μS / cm, and particularly up to 1000 μS / cm.

[0111] When filling a wind turbine, it is conceivable to directly prepare the coolant by diluting the concentrate with water at the desired dilution ratio. However, this has the drawback that both water and concentrate must be transported to the wind turbine and mixed there in the correct ratio, for example, using a pump or static mixer. Mixing of concentrate and water is generally carried out by energy input via shear energy. This can be done, for example, by dynamic mixing equipment, i.e., by mixing with a stirrer, or by pump circulation (natural or forced circulation) or by pump circulation by a static mixing unit (e.g., static mixer or nozzle) in a pump circuit, by static mixing equipment (e.g., static mixer, nozzle, baffle or Y or T piece) in the feed to the mixing vessel, or by dynamic mixing equipment (e.g., mixing pump or stirring tank).

[0112] Therefore, the coolant is typically prepared at a first location, for example in a formulater, by mixing a concentrate with water at a desired dilution ratio. The water-diluted coolant is then transported to a second location, the wind turbine, where the mixed coolant fills the wind turbine's cooling system.

[0113] When a new wind turbine is being installed, this second location is typically where the nacelle is assembled.

[0114] In the case of existing wind turbines, the second location is the location of the wind turbine itself, that is, at sea in the case of offshore turbines, or on land in the case of onshore turbines.

[0115] Existing wind turbines are filled at ambient temperature, preferably 15-35°C. The temperature must not fall below -10°C. Generally, the coolant needs to be transported up to the height of the wind turbine nacelle where the cooling system is located, and since the nacelle is 50-150m high, and in some designs even up to 200m high, the coolant must have a viscosity of 3mm at the discharge temperature when filling the wind turbine cooling system. 2 A temperature not exceeding / second, preferably 2.5mm 2Less than / second, more preferably 2mm 2 Less than / second, and more preferably 1.5mm 2 Less than / second, especially 1mm 2 The temperature must be less than or equal to 10°C / second; otherwise, it will be difficult to pump the coolant to this height. Low viscosity is desirable because it requires relatively low pump power, and cavitation may occur, for example, in the case of high-speed pumps. If the viscosity of the coolant is too high to pump, it may be useful to slightly heat the coolant to reduce its viscosity, and then transport the thus heated coolant to the wind turbine in an insulated or constant-temperature container. Generally, for this purpose, a coolant temperature up to 25°C higher than the ambient temperature, preferably up to 20°C, more preferably up to 15°C, and most preferably up to 10°C higher is sufficient.

[0116] Alternatively, the coolant can be transported by crane or hoist in a suitable container to the height of the wind turbine's coolant tank, where it can be replaced. This is particularly preferable when the viscosity of the coolant is too high to be pumped, or when a suitable pump is not available.

[0117] After replacement, the used coolant can be collected and disposed of, for example, in a wastewater treatment plant, or recovered.

[0118] wind turbine The components of a cooled wind turbine generally include at least one component selected from the group consisting of a generator, gearbox, bearings, converter, and operating system.

[0119] In a gearbox, the low-speed rotation of the rotor is converted into the high-speed rotation of the generator, thus allowing the use of a smaller generator. However, it is also possible to operate a wind turbine without a gearbox. In this case, the generator is directly coupled to the rotor and rotates at the same rotational speed as the rotor. This is a simpler design because it eliminates the need for a gearbox. However, the generator in a wind turbine without a gearbox must be much larger in design.

[0120] Therefore, gearboxes are not necessarily present in all wind turbines.

[0121] Using a hydraulically operated system, the rotor is generally automatically oriented towards the wind by the wind turbine's control system to optimize power generation (yawing). This includes both the orientation of the hub relative to the wind direction and the angle of attack of the rotor blades in the wind. If the wind is too strong, the rotor can also be oriented away from the wind or rotated to a so-called feathering position to protect the turbine.

[0122] In a preferred embodiment, the wind turbine gearbox (if present) and / or operating system are cooled, and the heat generated therein is dissipated through a coolant. In a particularly preferred embodiment, the gearbox and operating system are cooled within a common cooling circuit.

[0123] The rotor is rotated by the kinetic energy of the wind, driving a generator in the nacelle, which then converts mechanical energy into electrical energy. The power generated by the generator can then be supplied to the power grid. In most turbines, a converter ensures that the supplied power has a frequency of typically 50-60 Hz, as required by the national or regional power grid.

[0124] In a preferred embodiment, the wind turbine generator and / or converter are cooled, and the heat generated therein is dissipated through a coolant. In a particularly preferred embodiment, the generator and converter are cooled within a common cooling circuit.

[0125] The present invention further provides a method for thermal management of components of a wind turbine, and in this method, - Generator, - Gearbox, - Bearings, - Converters, and - Operating System Heat from at least one component of a wind turbine selected from the group consisting of is transferred at a relatively high temperature to the coolant via at least one first heat exchanger, the coolant is guided in a cooling circuit to at least one second heat exchanger, where the heat from the coolant is dissipated at a relatively low temperature, but here, - The coolant used is the above composition, - Relatively high temperatures are 20°C to 100°C, preferably 25°C to 80°C, more preferably 30°C to 60°C. - Relatively low temperatures are -50°C to 40°C, preferably -40°C to 40°C, more preferably -30°C to 35°C, and - Relatively low temperatures are at least 5°C, preferably at least 10°C, more preferably at least 15°C, and most preferably at least 20°C lower than relatively high temperatures.

[0126] A relatively high temperature is preferably the wall temperature of each component of the wind turbine during normal operation.

[0127] The relatively low temperature here is preferably the ambient temperature to which the heated coolant is in contact within the second heat exchanger. In the case of offshore wind turbines, a relatively low temperature can be the temperature of the seawater at the location of the wind turbine, but this is not very desirable. In this case, a relatively low temperature is 0°C to 30°C, preferably 1°C to 25°C, more preferably 2°C to 20°C, and most preferably 3°C to 15°C.

[0128] The advantage of the coolants described herein is that wind turbines having these coolants can generally operate for at least 5 years, preferably at least 7 years, more preferably at least 8 years, and most preferably at least 10 years without requiring coolant replacement. It is even conceivable that the coolant does not need to be replaced over the entire operating life of the wind turbine, i.e., up to 25 years, preferably up to 30 years.

[0129] All components of a heat exchanger may be known to those skilled in the art for these purposes.

[0130] Unless otherwise specified, amounts reported in percent, ppm, or parts refer to weight percent, weight ppm, or weight parts.

[0131] Viscosity data herein, unless otherwise specified, are related to ASTM D445 at 20°C. [Examples]

[0132] Coolant 1 of the present invention, based on ethylene glycol and containing a mixture of adipic acid, sebacic acid, and toltriazole as inhibitory components as described in the examples of International Publication No. 02 / 90462A1, underwent a corrosion test according to ASTM D1384 (corrosion test of glass products, 33% solution at 88°C for 336 hours). Negative values ​​indicate an increase in the weight of the test specimen.

[0133] Furthermore, ethylene glycol-based coolant 2, containing a mixture of molybdate, 2-ethylhexanoic acid, and toltriazole, underwent corrosion testing according to ASTM D1384. In this study, three metal plates from each sample were used for testing, and the weight loss results were rounded to one significant figure without decimal points.

[0134] Coolant 0, used as a less desirable coolant, was a commercially available product advertised as providing 6 years of protection in stationary plants. Wind turbines were not mentioned. According to the safety data sheet, the product contains 2-ethylhexanoic acid as an inhibitory component, and according to the accompanying product information, it does not contain nitrites, amines, phosphates, borates, or silicates. Furthermore, this coolant is likely to also contain sebacic acid.

[0135] Coolant 3 was based on ethylene glycol containing a mixture of sodium benzoate, nitrite, borate, silicate, and benzotriazole, and underwent corrosion testing in accordance with ASTM D1384.

[0136] Coolant 4 was based on ethylene glycol containing a mixture of silicates, borates, organic acids (sebacic acid and 2-ethylhexanoic acid), and benzotriazole, and underwent corrosion testing in accordance with ASTM D1384.

[0137] Coolant 5 is based on ethylene glycol containing a mixture of silicates, organic acids (sebacic acid, adipic acid, and dodecanedioic acid), and toltriazole, and was subjected to corrosion testing according to ASTM D1384.

[0138] [Table 1]

[0139] [Table 2]

[0140] Coolant 1 and especially coolant 2 show better corrosion results than coolant 0, particularly with respect to aluminum corrosion, and are therefore more suitable for cooling systems with aluminum components. Furthermore, coolants 3, 4, and 5 exhibit better corrosion results than coolant 0, not only in terms of non-ferrous metal corrosion (copper and brass corrosion) but also in terms of aluminum corrosion, and are therefore more suitable for cooling systems with aluminum components. Moreover, coolants 3, 4, and 5 show clear advantages in non-ferrous metal corrosion compared to coolants 1 and 2. Since seals and accessories are often made of such non-ferrous metals, the reduction in corrosion increases safety from leaks in the cooling system.

Claims

1. - At least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol, preferably monoethylene glycol, - Optionally, at least one organic mono or dicarboxylic acid, preferably an aliphatic mono or dicarboxylic acid, - At least one inorganic salt selected optionally from the group consisting of molybdate, borate, phosphate, silicate, nitrite, and nitrate, - At least one azole compound, - Water and, - Optionally, at least one silicate ester, - Optionally, if silicates are present, at least one silicophosphonate, - Optionally, further inhibitors and typical coolant components A coolant containing, In the aforementioned coolant, the combination of alkoxylated acetylene alcohol and a corrosion inhibitor having an imidazoline structure is excluded, However, provided that at least one mono- or dicarboxylic acid and / or at least one inorganic salt is present in the coolant, If the aforementioned at least one inorganic salt is not present, a further condition is that at least one dicarboxylic acid, preferably at least one aliphatic dicarboxylic acid, is present in the coolant. Coolant, Use in a cooling system for a wind turbine, preferably, - Generator, - Gearbox, - Bearings, - Converter, and - Operating system Use in a cooling system for thermal management of at least one component of a wind turbine, selected from the group consisting of the following.

2. The aforementioned coolant is - At least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol, preferably monoethylene glycol, - At least one inorganic salt selected from the group consisting of molybdate, borate, phosphate, silicate, nitrite, and nitrate, - At least one azole compound, - Water and, - Optionally, if silicates are present, at least one silicophosphonate, preferably, if silicates are present, at least one silicophosphonate, - Optionally, hard water stabilizers, bittering agents, defoaming agents and / or dyes Includes, However, this is subject to the condition that mono- or dicarboxylic acids are not present in the coolant. The use described in claim 1.

3. The aforementioned coolant is - At least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol, preferably monoethylene glycol, - At least one organic dicarboxylic acid, preferably at least one aliphatic dicarboxylic acid, more preferably without using a monocarboxylic acid, - At least one azole compound, - Water and, - Optionally, hard water stabilizers, bittering agents, defoaming agents and / or dyes Includes, However, this is subject to the condition that no inorganic salts selected from the group consisting of molybdate, borate, phosphate, silicate, nitrite, and nitrate are present in the coolant. The use described in claim 1.

4. The use according to claim 3, wherein the coolant comprises at least one aliphatic dicarboxylic acid and simultaneously does not contain an aliphatic monocarboxylic acid.

5. The aforementioned coolant is - At least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol, preferably monoethylene glycol, - At least one aromatic organic monocarboxylic acid, - At least one inorganic salt selected from the group consisting of molybdate, borate, phosphate, silicate, nitrite, and nitrate, - At least one azole compound, - Water and, - Optionally, if silicates are present, at least one silicophosphonate, preferably, if silicates are present, at least one silicophosphonate, - Optionally, hard water stabilizers, bittering agents, defoaming agents and / or dyes The use according to claim 1, including the use described in claim 1.

6. The aforementioned coolant is - At least one alkylene glycol, alkylene glycol monoalkyl ether or glycerol, preferably monoethylene glycol, - At least one organic mono or dicarboxylic acid, preferably an aliphatic mono or dicarboxylic acid, - At least one inorganic salt selected from the group consisting of molybdate, borate, phosphate, silicate and nitrate, preferably phosphate and silicate, more preferably silicate, - At least one azole compound, - Water and, - Optionally, if silicates are present, at least one silicophosphonate, preferably, if silicates are present, at least one silicophosphonate, - Optionally, hard water stabilizers, bittering agents, defoaming agents and / or dyes The use according to claim 1, including the use described in claim 1.

7. The coolant was prepared at 20°C in accordance with ASTM D445, with a thickness of 3 mm. ２ The use according to any one of claims 1 to 6, having a viscosity of less than or equal to / second.

8. The use according to any one of claims 1 to 7, wherein the azole compound is selected from the group consisting of benzotriazole and toltriazole.

9. The use according to any one of claims 1 to 8, wherein the at least one alkylene glycol, alkylene glycol monoalkyl ether, or glycerol is monoethylene glycol, preferably monoethylene glycol.

10. The use according to claim 5, wherein the organic monocarboxylic acid includes benzoic acid.

11. The use according to any one of claims 1, 3, or 6 to 9, wherein the organic monocarboxylic acid, unless otherwise excluded, comprises 2-ethylhexanoic acid or isononanoic acid, more preferably isononanoic acid.

12. The use according to any one of claims 1 or 3 to 9, wherein the organic dicarboxylic acid is selected from the group consisting of adipic acid, sebacic acid, and dodecanedioic acid, and preferably selected from the group consisting of adipic acid and sebacic acid.

13. The use of the coolant according to any one of claims 1 to 12, wherein the coolant is used for thermal management of a generator and / or converter.

14. The use of the coolant according to any one of claims 1 to 12, wherein the coolant is used for thermal management of the gearbox and / or operating system.

15. A method for filling a cooling system for a wind turbine with a coolant, wherein at a first location, - 0.1% to 15% by weight of water, - 50% to 95% by weight of alkylene glycol, alkylene glycol monoalkyl ether, and glycerol, - The following components in total, ranging from 0.5% to 15% by weight: --Optionally, at least one organic mono or dicarboxylic acid, preferably an aliphatic mono or dicarboxylic acid, -- At least one inorganic salt selected optionally from the group consisting of molybdate, borate, phosphate, silicate, nitrite, and nitrate, -- At least one azole compound, --Optionally, at least one silicate ester, --Optionally, if silicates are present, at least one silicophosphonate and - Optionally, 0% to a maximum of 3% by weight of further inhibitors and typical coolant components A concentrate containing, In the aforementioned coolant, the combination of alkoxylated acetylene alcohol and a corrosion inhibitor having an imidazoline structure is excluded, However, the sum of all components must always be 100% by weight. Provided that at least one mono- or dicarboxylic acid and / or at least one inorganic salt is present in the coolant, If the aforementioned at least one inorganic salt is absent, the concentrate is further provided that at least one dicarboxylic acid, preferably at least one aliphatic dicarboxylic acid, is present in the coolant. It is mixed with water in a volume ratio of 1:1 to 1:

3. A method comprising transporting the material to the wind turbine at a second location, where it is filled into the cooling system of the wind turbine.

16. The wind turbine, according to ASTM D445, has a coolant of 3 mm ２ The method according to claim 15, wherein the filling is performed at a temperature having a viscosity of less than or equal to 1 / second.

17. A method for thermal management of components of a wind turbine, - Generator, - Gearbox, - Bearings, - Converter, and - Operating system Heat from at least one component of a wind turbine, selected from the group consisting of the following, is transferred at a relatively high temperature to a coolant via at least one first heat exchanger, the coolant is guided in a cooling circuit to at least one second heat exchanger, where the heat from the coolant is dissipated at a relatively low temperature, but here, - The coolant used is the composition described in any one of claims 1 to 12. - The aforementioned relatively high temperature is 20°C to 100°C, preferably 25°C to 80°C, more preferably 30°C to 60°C. - The relatively low temperature is -50°C to 40°C, preferably -40°C to 40°C, more preferably -30°C to 35°C, and - A method wherein the relatively low temperature is at least 5°C, preferably at least 10°C, more preferably at least 15°C, and most preferably at least 20°C lower than the relatively high temperature.

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