EP-4735555-A1 - NEW USES FOR COOLANTS

Abstract

The present invention relates to new uses for coolants in wind turbine cooling systems.

Inventors

• FOERSTER, UWE
• KRKLJUS, Ivana
• Wendling, Timo
• MAYER, GUIDO

Assignees

• BASF SE

Dates

Publication Date

20260506

Application Date

20240620

Claims (17)

1. 1 . Use of a coolant containing - at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerin, preferably monoethylene glycol, - optionally at least one organic mono- or dicarboxylic acid, preferably aliphatic mono- or dicarboxylic acid, - optionally at least one inorganic salt selected from the group consisting of molybdates, borates, phosphates, silicates, nitrites and nitrates, - at least one azole compound, - Water, - optionally at least one silicic acid ester, - optionally at least one silicophosphonate, if silicates are present, and - optionally further inhibitors and coolant-typical components, excluding a combination of alkoxylated acetylenic alcohol and corrosion inhibitors with imidazoline structure in the coolant, with the proviso that at least one mono- or dicarboxylic acid and/or at least one inorganic salt is present in the coolant, and with the further proviso that in the absence of the at least one inorganic salt, at least one dicarboxylic acid, preferably at least one aliphatic dicarboxylic acid is present in the coolant, in a cooling system of wind turbines, preferably in a cooling system for heat management of at least one component of a wind turbine selected from the group consisting of - Generator, - Gearbox, - warehouse, - Converter and - adjustment system.
2. 2. Use according to claim 1, characterized in that the coolant - at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerin, preferably monoethylene glycol - at least one inorganic salt selected from the group consisting of molybdates, borates, phosphates, silicates, nitrites and nitrates, - at least one azole compound - Water - optionally at least one silicophosphonate, if silicates are present, preferably at least one silicophosphonate, if silicates are present, and - optional hard water stabilizer, bitter agent, defoamer and/or colorant provided that no mono- or dicarboxylic acids are present in the coolant.
3. 3. Use according to claim 1, characterized in that the coolant - at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerin, preferably monoethylene glycol - at least one organic dicarboxylic acid, preferably at least one aliphatic dicarboxylic acid, particularly preferably at least one aliphatic dicarboxylic acid without monocarboxylic acids, - at least one azole compound - Water - optionally contains hard water stabilizer, bitter agent, defoamer and/or colorant, with the proviso that no inorganic salts selected from the group consisting of molybdates, borates, phosphates, silicates, nitrites and nitrates are present in the coolant.
4. 4. Use according to claim 3, characterized in that the coolant contains at least one aliphatic dicarboxylic acid and at the same time no aliphatic monocarboxylic acids are present.
5. 5. Use according to claim 1, characterized in that the coolant - at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerin, preferably monoethylene glycol - at least one aromatic organic monocarboxylic acid, - at least one inorganic salt selected from the group consisting of molybdates, borates, phosphates, silicates, nitrites and nitrates, - at least one azole compound - Water - optionally at least one silicophosphonate, if silicates are present, preferably at least one silicophosphonate, if silicates are present, and - optionally contains hard water stabilizer, bitter agent, defoamer and/or colorant.
6. 6. Use according to claim 1, characterized in that the coolant - at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerin, preferably monoethylene glycol - at least one organic mono- or dicarboxylic acid, preferably aliphatic mono- or dicarboxylic acid, - at least one inorganic salt selected from the group consisting of molybdates, borates, phosphates, silicates and nitrates, preferably selected from the group consisting of phosphates and silicates, particularly preferably a silicate, - at least one azole compound - Water - optionally at least one silicophosphonate, if silicates are present, preferably at least one silicophosphonate, if silicates are present, and - optionally contains hard water stabilizer, bitter agent, defoamer and/or colorant.
7. 7. Use according to one of the preceding claims, characterized in that the coolant has a Viscosity at 20 °C according to ASTM D445 of not more than 3 mm 2 /s.
8. 8. Use according to one of the preceding claims, characterized in that the azole compound is selected from the group consisting of benzotriazole and tolutriazole.
9. 9. Use according to one of the preceding claims, characterized in that the at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerin is monoethylene glycol, preferably that it consists of monoethylene glycol.
10. 10. Use according to claim 5, characterized in that the organic monocarboxylic acid comprises benzoic acid.
11. 11. Use according to one of claims 1, 3 or 6 to 9, characterized in that the organic Monocarboxylic acid, unless excluded, 2-ethylhexanoic acid or isononanoic acid, particularly preferably isononanoic acid.
12. 12. Use according to one of claims 1 or 3 to 9, characterized in that the organic dicarboxylic acid is selected from the group consisting of adipic acid, sebacic acid and dodecanedioic acid, preferably from the group consisting of adipic acid and sebacic acid.
13. 13. Use according to one of the preceding claims, characterized in that the coolant for thermal management of generator and/or converter.
14. 14. Use according to one of claims 1 to 12, characterized in that the coolant is used for heat management of the transmission and/or actuating system.
15. 15. A method for filling the cooling system of a wind turbine with a coolant, in which a concentrate containing - 0.1 to 15 wt% water - 50 to 95% by weight alkylene glycol, alkylene glycol monoalkyl ether and glycerin, - in total 0.5 to 15 wt% of the following components: - optionally at least one organic mono- or dicarboxylic acid, preferably aliphatic mono- or dicarboxylic acid, - optionally at least one inorganic salt selected from the group consisting of molybdates, borates, phosphates, silicates, nitrites and nitrates, - at least one azole compound - optionally at least one silicic acid ester, - optionally at least one silicophosphonate, if silicates are present, and - optionally 0 up to 3% by weight of further inhibitors and coolant-typical components, excluding a combination of alkoxylated acetylenic alcohol and corrosion inhibitors with imidazoline structure in the coolant, with the proviso that the sum of all components always amounts to 100% by weight, with the proviso that at least one mono- or dicarboxylic acid and/or at least one inorganic salt is present in the coolant, and with the further proviso that in the absence of the at least one inorganic salt, at least one dicarboxylic acid, preferably at least one aliphatic dicarboxylic acid, is present in the coolant, mixed with water in a volume ratio of 1:1 to 1:3, transported to the wind turbine at a second location and filled there the cooling system of the wind turbine.
16. 16. Method according to claim 15, characterized in that the filling of the wind turbine at a temperature at which the coolant has a viscosity according to ASTM D445 of not more than 3 mm 2 /s.
17. 17. A method for heat management of components of wind turbines, in which heat from at least one component of a wind turbine selected from the group consisting of - Generator, - Gearbox, - warehouse, - Converter and - control system at a higher temperature is transferred to a coolant via at least one first heat exchanger, this coolant is fed in a cooling circuit to at least one second heat exchanger and there, at a lower temperature, heat is removed from the coolant by - a composition as in any one of claims 1 to 12 is used as coolant, - the higher temperature is from 20 to 100 °C, preferably 25 to 80, particularly preferably 30 to 60 °C, - the lower temperature is between minus 50 and 40 °C, preferably between minus 40 and 40, particularly preferably between minus 30 and 35 °C and - the lower temperature is at least 5 °C, preferably at least 10, particularly preferably at least 15 and most preferably at least 20 °C lower than the higher temperature.

Description

New Applications for Coolants Description The present invention relates to preferred coolants in cooling systems of wind turbines. Coolants for motor vehicles have been known for a long time and are used to dissipate heat, particularly from combustion engines. In wind turbines, heat is also released during operation and must be dissipated in order to protect mechanical or electrical systems such as generators, gearboxes, bearings, converters and control systems from overheating. Compared to motor vehicles, service and maintenance work on wind turbines is much more complicated and time-consuming, particularly for offshore wind turbines, so that an extension of the service intervals is particularly desirable. In addition, different requirements are placed on coolants in wind turbines than in motor vehicles, as different materials are used in their cooling systems and the operating conditions differ from those of a motor vehicle. For example, coolants in motor vehicle combustion engines are exposed to higher wall temperatures and thus higher thermal stress, whereas in wind turbines, high corrosion inhibition of the materials used and maintenance intervals of at least 5 years are required. It is therefore not possible to simply transfer a coolant for motor vehicles to the requirements of a wind turbine. EP 3828411 A1 describes a wind turbine and a method for operating it. A coolant is also mentioned, which is said to be water, glycol or a mixture thereof. However, this type of coolant does not meet the above requirements for a coolant for wind turbines. EP 3828411 A1 does not contain any statements on, for example, corrosion resistance, viscosity, stability, temperature resistance or electrical conductivity of the coolant. According to the available machine translation, CN 109837071 B describes coolants for wind power generators made of ethylene glycol, aliphatic monocarboxylic acid, azole component, defoamer and water as well as a corrosion inhibitor mixture of alkoxylated acetylenic alcohol and imidazolines as corrosion inhibitor. The coolants thus described have an electrical conductivity below 200 piS/cm. The disadvantage of these coolants is that in order to achieve the required low electrical conductivity, the described corrosion inhibitor mixture must be used, which is not commercially available and therefore increases the cost of these coolants. Furthermore, only aliphatic monocarboxylic acids are described as other corrosion inhibitors. The object of the present invention was therefore to provide coolants that meet the special requirements of wind turbines and the special features of their operation. The problem was solved by using a coolant containing - at least one alkylene glycol, alkylene glycol monoalkyl ether or glycerin, preferably monoethylene glycol, - optionally at least one organic mono- or dicarboxylic acid, preferably aliphatic mono- or dicarboxylic acid, - optionally at least one inorganic salt selected from the group consisting of molybdates, borates, phosphates, silicates, nitrites and nitrates, - at least one azole compound, - Water, - optionally at least one silicic acid ester, - optionally at least one silicophosphonate, if silicates are present, and - optionally further inhibitors and coolant-typical components, with the proviso that at least one mono- or dicarboxylic acid and/or at least one inorganic salt are present in the coolant, in a cooling system of wind turbines, preferably in a cooling system for heat management of at least one component of a wind turbine selected from the group consisting of - Generator, - Gearbox, - warehouse, - Converter and - adjustment system. These coolants and in particular the embodiments listed below meet the requirements and have a sufficient corrosion-inhibiting effect for the cooling systems used as well as sufficient stability of the components contained in the coolant, so that the durability of the coolant is increased and thus the maintenance intervals are extended. It was found that the upper limit of the electrical conductivity of 200 piS/cm for the coolant set in accordance with CN 109837071 B is not absolutely necessary, but can be abandoned in favor of a higher content of corrosion inhibitors, which ensures a corrosion-inhibiting effect over the required long operating time in wind turbines. In particular, according to the invention, the corrosion inhibitor composition of CN 109837071 B consisting of alkoxylated acetylenic alcohol and imidazoline corrosion inhibitor is dispensed with, in particular propynol alkoxylate, butynediol alkoxylate and octynol alkoxylate as alkoxylated acetylenic alcohols and carboxyethylimidazoline, heptadecenylamine ethylimidazoline and heptadecenylamine ethylimidazoline quaternary ammonium salts. The presence a combination of alkoxylated acetylenic alcohol and corrosion inhibitors with imidazoline structure in the coolant according to the invention is excluded according to the present invention. A high lev