Heat transfer fluids for indirect liquid cooling systems

Abstract

The invention relates to the use of a heat transfer fluid based on aliphatic monoesters for indirect cooling of electronic components.

Description

[0001] describe Invention Field This application relates to the use of aliphatic monoester-based heat transfer fluids for the indirect cooling of electronic components. background

[0002] Today, heat dissipation is a relevant topic in the design and operation of electronic devices, especially those containing densely packaged electronic circuit components, particularly semiconductor-type circuit components such as integrated circuits. For example, in modern server farms and in telecommunications centers and data centers, heat dissipation is a serious problem, where the increasing number of hard drives, microprocessors, or central processing units (CPUs) and their processing and storage power make heat dissipation a critical factor in preventing overheating of such electronic components, which can lead to malfunctions and irreparable damage to these components.

[0003] Therefore, in the field of electronic device design and operation, there is a strong sense of need to discover and develop new and improved cooling systems.

[0004] Today, there are different cooling systems that use various technologies to transfer heat away from electronic components in order to maintain the appropriate operating temperature of the electronic components; cooling systems can be classified based on the type of heat transfer fluid and whether the heat transfer occurs in direct or indirect contact with the electronic components.

[0005] Indirect cooling systems are designed to dissipate heat generated by electronic components without allowing the heat transfer fluid to come into direct contact with them. Common types of indirect cooling systems, based on the physical state and type of the heat transfer fluid and the heat dissipation mechanism, include: - Air Cooling Systems: This type of cooling system is the most widely used method for indirect cooling of electronic components. It utilizes fans and heat sinks for heat dissipation. Fans, whether active (powered) or passive (relying on natural convection), enhance airflow around the heat sink, thereby improving heat dissipation. Air cooling systems are relatively simple, cost-effective, and suitable for many applications. However, their effectiveness may be limited in high-power or densely packed systems.

[0006] - Phase change cooling systems: These involve using a refrigerant that changes from a liquid to a gaseous state and then back to a liquid state. The cooling process begins with the refrigerant absorbing heat from the electronic components, causing it to evaporate into a gas. The gaseous refrigerant then condenses back into a liquid state through a heat exchanger, releasing the absorbed heat. The liquid refrigerant then flows back to the components, repeating the cycle.

[0007] - Liquid cooling systems: Liquid cooling systems use a liquid heat transfer fluid to remove heat from electronic components. This method is more efficient than air cooling systems and is cheaper and requires less complex systems compared to phase change cooling systems.

[0008] Typically, an indirect liquid cooling system includes a cooling loop for circulating a heat transfer fluid, a pump system for circulating the heat transfer fluid throughout the cooling loop, a heat-conducting element coupled to electronic components to absorb heat from the electronic components and transfer said heat to the heat transfer fluid, a heat exchanger for dissipating the heat absorbed by the heat transfer fluid and cooling the heat transfer fluid, and optionally a reservoir for containing the heat transfer fluid. In these systems, the heat transfer fluid is pumped by the pump system through the cooling loop, where it comes into thermal contact with the heat-conducting element and absorbs heat from the heat-conducting element in this way. Thus, the heat transfer fluid dissipates the heat generated by the electronic components, and is then stored in a reservoir while being cooled by the heat exchanger before recirculation in the loop, or while being cooled before subsequent recirculation in the loop.

[0009] Therefore, given the rheological and hydrodynamic properties, thermal and chemical stability, and heat capacity of heat transfer fluids, the heat transfer fluids used in liquid cooling systems play a crucial role in heat dissipation and the performance of the system itself. Currently, the known fluids for indirect liquid cooling are water and specialized fluids, among which fluids containing PFAS (perfluorinated and polyfluorinated substances) have been widely used. Invention Overview

[0010] However, the applicant notes that even though water is a common choice due to its excellent thermal properties and availability, complex and expensive purification systems are required to overcome the risks of corrosion and scaling, which can lead to malfunctions and damage to cooling systems and electronic components. Furthermore, water has a limited operating temperature window, which further restricts the cooling efficiency of systems using water.

[0011] The applicant also noted that even though specialty fluids (such as those containing PFAS) have enhanced properties, such as higher boiling points or better corrosion resistance, thus allowing them to be used in specialty applications, these compounds have recently shown technical and application limitations.

[0012] In fact, PFAS tend to be highly volatile, which leads to some loss of these fluids due to evaporation when exposed to high-temperature components. This high volatility and partial loss of PFAS necessitates their refilling into the heat exchange system, while simultaneously increasing operator exposure to the fluids.

[0013] At the same time, PFAS have also raised concerns about their environmental impact, making their use particularly critical and requiring complex and expensive closed systems to prevent any diffusion and / or contact with the external environment during the operation, transport, and maintenance of systems and devices using them.

[0014] Therefore, the object of the present invention is to provide a novel heat transfer fluid that overcomes the functional and environmental limitations of heat transfer fluids currently used in indirect liquid cooling systems for electronic components, and the applicant has surprisingly found that heat transfer fluids based on a specific class of aliphatic monoesters can be effectively used for such purposes.

[0015] In particular, in a first aspect, the present invention relates to the use of a heat transfer fluid for cooling electronic components in an indirect liquid cooling system, the heat transfer fluid comprising at least one C6-C 12 An aliphatic monohydric alcohol and at least one monoester of at least one straight-chain or branched C2-C7 aliphatic monocarboxylic acid.

[0016] Surprisingly, the applicant did find that such monoesters exhibit suitable rheological and hydrodynamic properties, thermal and chemical stability properties, and heat capacity properties, making them effectively suitable for use in indirect liquid cooling systems for dissipating heat generated by electronic components.

[0017] Advantageously, the monoester can also provide a more environmentally sustainable solution compared to dedicated fluids based on PFAS, making the operation, transportation, and maintenance of the cooling system less critical.

[0018] Notably, these monoesters offer excellent alternatives to PFAS-based fluids, particularly due to their significantly low dynamic viscosity at extremely low temperatures. This unique property enables highly efficient pumpability and circulation of heat transfer fluids, even in the harshest cold environments. Furthermore, these esters possess high flash points and low volatility, ensuring both the safety and effective cooling of electronic devices at elevated temperatures. Their unique combination of low viscosity, high flash point, and low volatility makes these monoesters ideal for cooling systems in various types of indirect electronic devices, providing efficient thermal management for a range of electronic devices, offering reliable and efficient heat transfer capabilities while prioritizing safety and performance.

[0019] These fluids have low viscosity, which facilitates the efficient transfer of heat from electronic components in various types of indirect cooling systems. At the same time, the high flash point and low volatility of these esters ensure safe operation and minimize the risk of fire or malfunction in such systems.

[0020] For example, such monoesters can be used as working fluids in heat pipes or narrow channels or pipes, and are widely used for indirect cooling of electronic devices. These monoesters enable efficient heat transfer under such conditions, allowing heat to be absorbed from the source and dissipated at the sink. The fluid's low viscosity at operating temperature ensures optimal circulation through narrow channels or pipes, and thus enhances overall cooling performance even with limited contact time and heat transfer surface area.

[0021] Compared to direct cooling systems, especially those using immersion baths, this has very stringent requirements on viscosity. In direct cooling systems, the heat transfer fluid is not forced through narrow spaces, and the contact time and heat transfer surface area are greater than in indirect cooling systems.

[0022] Therefore, in indirect cooling systems with closed loops, such monoesters can be advantageously used as heat transfer fluids circulating through the closed-loop system. Due to their low dynamic viscosity at operating temperatures, these fluids can easily flow through narrow channels and complex cooling structures, effectively removing heat from electronic components. Their high flash point and low volatility enhance the safety and reliability of the cooling system.

[0023] Therefore, these monoesters can also be effectively used in cold plate cooling systems, where they can advantageously flow over metal plates in direct contact with electronic components. The low viscosity of these fluids allows for efficient heat transfer, enabling effective cooling of high-power electronic devices. The high flash point and low volatility of the esters ensure safe operation and minimize the risk of fluid leakage or system damage.

[0024] In this way, more efficient and safer use of electronic devices with installed electronic components can be achieved by improving their thermal management and avoiding or at least significantly reducing overheating of the electronic components installed therein, which can lead to malfunction and irreparable damage to the electronic components.

[0025] Furthermore, the low viscosity of the monoester at low temperatures allows for the establishment and use of a high and constant temperature difference between the thermal electronic components and the heat transfer fluid, making heat exchange more efficient and rapid. Maintaining a constant temperature as much as possible, avoiding thermal changes, or eliminating thermal changes as quickly as possible are fundamental requirements for cooling electronic components, especially semiconductor-based electronic components.

[0026] In another aspect, the present invention also relates to a method for cooling electronic components using an indirect liquid cooling system, wherein the liquid cooling system includes a heat transfer fluid as defined in the first aspect of the invention.

[0027] In another aspect, the present invention also relates to an electronic device comprising: At least one electronic component; and At least one indirect liquid cooling system adapted to cool the electronic components and comprising at least one heat transfer fluid as defined in the first aspect of the invention.

[0028] The advantages of the methods and electronic devices according to these aspects of the invention have been disclosed with respect to the use according to the first aspect of the invention, and will not be repeated here. Invention Details

[0029] In a first aspect, the present invention relates to the use of a heat transfer fluid for cooling electronic components in an indirect liquid cooling system, the heat transfer fluid comprising at least one C6-C 12 An aliphatic monohydric alcohol and at least one monoester of at least one straight-chain or branched C2-C7 aliphatic monocarboxylic acid.

[0030] Surprisingly, the applicant did find that such monoesters exhibited suitable rheological and hydrodynamic properties, thermal and chemical stability properties, and heat capacity properties, making them effectively suitable for use in indirect liquid cooling systems for dissipating heat generated by electronic components.

[0031] Within the framework of this description and in the following claims, unless otherwise indicated, all numerical entities representing quantities, parameters, percentages, etc., shall be understood to be preceded by the term "about" in all cases. As used herein, the term "about" will be understood by those skilled in the art and will vary to some extent depending on the context in which it is used. As used herein, when referring to measurable values ​​such as quantities, durations of time, and similar values, the term "about" means including variations of ±20% or ±10% from the specified value, including ±5%, ±1%, and ±0.1%, because such variations are suitable for carrying out the disclosed methods.

[0032] Furthermore, the entire range of digital entities includes all possible combinations of maximum and minimum values, as well as all possible intermediate ranges, except for those specifically noted below.

[0033] Unless otherwise defined, all technical and scientific terms used herein generally have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0034] As used in this article, the articles “a” and “an” refer to one or more (i.e., at least one) grammatical object of that article. By instance, “an element” means one or more elements.

[0035] As used herein, the term "indirect liquid cooling system" means a cooling system in which the heat transfer fluid is (or remains) in a liquid or predominantly liquid state during the operation of the system, and wherein the heat transfer fluid does not directly contact the component to be cooled, while being suitable for cooling that component. In particular, when electronic components are involved, an indirect liquid cooling system is a cooling system in which the heat transfer fluid does not directly contact such electronic components, for example, by inserting a different element that is thermally coupled to the electronic component and is made of a thermally conductive material (such as copper or other metals) between the electronic component and the heat transfer fluid. This thermally conductive element prevents direct contact between the fluid and the electronic component and has the function of transferring heat. In an indirect cooling system, depending on the system design, such a different element inserted between the electronic component and the heat transfer fluid can have different shapes and configurations (heat sink, wall in a tube, or plate).

[0036] In indirect cooling, heat transfer involves both conduction and convection, as the fluid exchanges heat with the material thermally coupled to the part being cooled, and the heat exchange is primarily influenced by the temperature difference between the part being cooled and the heat transfer fluid.

[0037] The present invention may contain one or more of the features disclosed below in one or more of the above aspects.

[0038] According to the present invention, the heat transfer fluid contains at least one C6-C 12 An aliphatic monohydric alcohol and at least one monoester of at least one straight-chain or branched C2-C7 aliphatic monocarboxylic acid are used for cooling electronic components in an indirect liquid cooling system.

[0039] Preferably, the C6-C 12 Aliphatic monohydric alcohols are selected from the group consisting of: 1-hexanol, 1-octanol, 2-ethylhexanol, isononol, 3,5,5-trimethylhexanol, 2-propylheptanol, 1-decanol, isodecanol (8-methyl-1-nonanol), isoundecanol (9-methyl-1-decanol), lauryl alcohol (dodecyl alcohol), 2,4-diethyloctanol, and mixtures thereof.

[0040] Preferably, the aliphatic monohydric alcohol of the monoester according to the present invention is C6-C. 10 The monohydric alcohol is more preferably selected from the group consisting of: 1-hexanol, 1-octanol, 2-ethylhexanol, isononol, 3,5,5-trimethylhexanol, 2-propylheptanol, 1-decanol, isodecanol (8-methyl-1-nonanol), and mixtures thereof.

[0041] In a preferred embodiment, the aliphatic monohydric alcohol of the monoester according to the invention is selected from the group consisting of 2-ethylhexanol, 2-propylheptanol and mixtures thereof.

[0042] Preferably, the straight-chain or branched C2-C7 aliphatic monocarboxylic acid is a C5-C7 aliphatic monocarboxylic acid, more preferably selected from the group consisting of 2-methylbutyric acid, 3-methylbutyric acid, valeric acid, hexanoic acid, heptanoic acid and mixtures thereof.

[0043] In a preferred embodiment of the present invention, the monoester is selected from the group consisting of 2-propylheptanol valerate and 2-ethylhexanol heptanate.

[0044] As defined above, monohydric alcohols, monocarboxylic acids, and monoesters do indeed exhibit a surprising combination of properties, such as low dynamic viscosity at temperatures up to -55°C combined with flash points above 125°C and high volume resistivity, making them particularly suitable and effective in indirect electronic device cooling systems within a wide temperature range window from -55°C to 125°C, and thus particularly effective as components of heat transfer fluids in indirect liquid cooling systems for electronic components.

[0045] In addition to the monoester, the heat transfer fluid according to the invention may advantageously contain one or more other components, such as synthetic or natural esters, mineral oils, polyethers such as polyalkylene glycols, polyolefins, and additives.

[0046] In embodiments, the heat transfer fluid according to the invention comprises at least one monoester as defined above and at least one diester of at least one C2-C9 aliphatic diol and at least one straight-chain or branched C2-C7 aliphatic monocarboxylic acid, such as diesters of 1,2-propanediol divalerate or 1,3-propanediol divalerate.

[0047] Preferably, the heat transfer fluid according to the invention comprises at least one additive selected from the group consisting of: antioxidants, pour point depressants, defoamers, corrosion inhibitors, viscosity modifiers, wear-resistance and / or extreme-pressure additives, friction modifiers, detergents, dispersants, and mixtures thereof.

[0048] Advantageously, the heat transfer fluid according to the invention exhibits one or more of the following characteristics: - Dynamic viscosity less than 50 mPa*s at -30℃; - Flash point above 125℃; - Volume resistivity above 0.1 megohm-cm (TΩ*cm) at 25°C.

[0049] Furthermore, the heat transfer fluid according to the invention exhibits suitable heat capacity and thermal conductivity properties for cooling electronic components.

[0050] Preferably, the heat transfer fluid according to the invention is in a liquid state during operation of the indirect liquid cooling system.

[0051] In the indirect liquid cooling system according to the invention, the heat transfer fluid has the function of dissipating heat generated by electronic components, which can be advantageously installed in electronic devices.

[0052] In indirect cooling, heat transfer involves both conduction and convection, as the fluid exchanges heat with the material thermally coupled to the component being cooled, and this heat exchange is primarily influenced by the temperature difference between the component being cooled and the heat transfer fluid. Another well-known factor affecting heat exchange is the amount of heat exchange fluid used, which is itself limited by the design of the cooling system.

[0053] Due to the advantageous properties of the heat transfer fluid according to the invention, there are no particular limitations on the indirect liquid cooling system, and it can be any type of indirect liquid cooling system for indirect cooling of electronic components known to those skilled in the art.

[0054] Preferably, the indirect liquid cooling system according to the invention includes at least one thermally conductive element thermally coupled to the electronic component, and the thermally conductive element is adapted to transfer heat from the electronic component to the heat transfer fluid. More preferably, the thermally conductive element is selected from the group consisting of: walls, layers, radiators, cold plates, heat pipes, and vapor chambers.

[0055] Preferably, the indirect liquid cooling system includes: A liquid cooling circuit adapted to circulate the heat transfer fluid; A pump adapted to pump the heat transfer fluid throughout the liquid cooling circuit; A heat exchanger adapted to cool the heat transfer fluid; and Optionally, a reservoir suitable for containing the heat transfer fluid.

[0056] According to the present invention, the electronic component can be any type of electronic component that tends to generate heat during use and therefore needs to be cooled, or an electronic component that may suffer malfunction and irreparable damage after overheating.

[0057] Preferably, the electronic component is selected from the group consisting of: microprocessors, semiconductor wafers, power control semiconductors, electrochemical cells, electrical distribution switch gears, power transformers, circuit boards, multi-chip modules, hard disks, central processing units, packaged or unpackaged semiconductor devices, fuel cells, lasers, and semiconductor integrated circuits.

[0058] More preferably, the electronic component is selected from the group consisting of: microprocessors, semiconductor wafers, power control semiconductors, circuit boards, multi-chip modules, hard disks, central processing units, packaged or unpackaged semiconductor devices, and semiconductor integrated circuits.

[0059] Preferably, the electronic component is installed in an electronic device.

[0060] According to the present invention, the electronic device can be any type of electronic device with electronic components installed, and there are no particular limitations. Preferably, the electronic device is selected from the group consisting of: computers, servers, server clusters, telecommunications centers, and data centers.

[0061] Due to the properties of the heat transfer fluid according to the present invention, a more efficient and safer cooling method for electronic components can be achieved by improving the thermal management of electronic components and avoiding or significantly reducing overheating phenomena that may lead to malfunctions and irreparable damage.

[0062] Therefore, in another aspect, the present invention also relates to a method for cooling electronic components using an indirect liquid cooling system, wherein the liquid cooling system includes a heat transfer fluid comprising at least one C6-C 12 An aliphatic monohydric alcohol and at least one monoester of at least one straight-chain or branched C2-C7 aliphatic monocarboxylic acid, as defined above in the first aspect of the invention.

[0063] The advantages and preferred features of this method have already been defined above with respect to the first aspect of the invention, and therefore will not be repeated here.

[0064] In the method according to this aspect of the invention, a heat transfer fluid as defined in the first aspect of the invention is used. Therefore, the preferred characteristics of this heat transfer fluid have already been defined above with respect to the heat transfer fluid in the first aspect of the invention, and will therefore not be repeated here.

[0065] Preferred features of the indirect liquid cooling system and electronic components according to the method of the present invention have already been defined above with respect to the indirect liquid cooling system and electronic components of the first aspect of the present invention, and therefore will not be repeated here.

[0066] Preferably, the method for cooling electronic components according to the present invention includes the step of transferring heat from the electronic components to the heat transfer fluid.

[0067] In a preferred embodiment, when the indirect liquid cooling system includes at least one thermally conductive element thermally coupled to the electronic component in the method according to the invention, the thermally conductive material is adapted to transfer heat from the electronic component to the heat transfer fluid in the heat transfer step.

[0068] By using heat transfer fluids containing monoesters as defined above in indirect liquid cooling systems for cooling electronic components, more efficient and safer use of electronic devices with installed electronic components can be achieved by improving their thermal management and avoiding or significantly reducing overheating phenomena that could lead to malfunctions and irreparable damage.

[0069] Therefore, in another aspect, the present invention relates to an electronic device comprising: At least one electronic component; and At least one indirect liquid cooling system adapted to cool the electronic components and comprising at least one heat transfer fluid containing at least one C6-C 12 An aliphatic monohydric alcohol and at least one monoester of at least one straight-chain or branched C2-C7 aliphatic monocarboxylic acid, as defined above in the first aspect of the invention.

[0070] The advantages and preferred features of the electronic device according to the invention have been disclosed with respect to other uses and methods according to the invention, and will not be repeated here.

[0071] In the apparatus according to this aspect of the invention, a heat transfer fluid and an indirect liquid cooling system as defined in other aspects of the invention are used. Therefore, preferred features of this heat transfer fluid and indirect liquid cooling system have already been defined above with respect to heat transfer fluids and indirect liquid cooling systems in other aspects of the invention, and will therefore not be repeated here.

[0072] Preferably, the electronic device according to this aspect of the invention is selected from the group consisting of: computer, server, server cluster, telecommunications center, and data center.

[0073] Preferably, in the apparatus according to this aspect of the invention, the electronic components of the apparatus according to this aspect of the invention are selected from the group consisting of: microprocessors, semiconductor wafers, power control semiconductors, electrochemical cells, power distribution switchgear, power transformers, circuit boards, multi-chip modules, hard disks, central processing units, packaged or unpackaged semiconductor devices, fuel cells, lasers, and semiconductor integrated circuits.

[0074] More preferably, the electronic component is selected from the group consisting of: microprocessors, semiconductor wafers, power control semiconductors, circuit boards, multi-chip modules, hard disks, central processing units, packaged or unpackaged semiconductor devices, and semiconductor integrated circuits.

[0075] In another aspect, the present invention also relates to a heat transfer fluid for cooling electronic components, comprising at least one C6-C 12The aliphatic monohydric alcohol and at least one monoester of at least one straight-chain or branched C2-C7 aliphatic monocarboxylic acid, and at least one additive, said additive being selected from the group consisting of: antioxidants, pour point depressants, defoamers, corrosion inhibitors, viscosity modifiers, abrasion-resistant and / or extreme pressure additives, friction modifiers, detergents, dispersants, and mixtures thereof.

[0076] The advantages and preferred features of the heat transfer fluid according to the invention have been disclosed with respect to other uses and methods according to the invention, and will not be repeated here.

[0077] Therefore, the preferred features of the heat transfer fluid according to this other aspect of the invention have already been defined above with respect to the heat transfer fluid in the first aspect of the invention, and will therefore not be repeated here.

[0078] Further features and advantages of the invention will become more apparent from the following description of some preferred embodiments of the invention through the following non-limiting examples.

[0079] Experimental Section Example 1 – Preparation of 2-propylheptanol valerate 607.8 g (3.84 mol) of 2-propylheptanol was charged into a multi-necked reaction flask equipped with an anchor stirrer, a Vigreux column, a condenser, and a distillation vessel. 490 g (4.8 mol) of valeric acid and 3 g of sodium hypophosphite monohydrate were added to the flask. Stirring was initiated and the system was purged with nitrogen, then the temperature was raised to boiling of the reaction mixture. The reaction was then allowed to continue until 100% stoichiometric amount of water, equivalent to 100% esterification yield, was evaporated. Unreacted valeric acid was then removed by vacuum distillation until an acid value less than 5 mg KOH / g was obtained. A stoichiometric excess of 4 wt% aqueous sodium hydroxide solution relative to the amount required to neutralize the acid value was added to the esterification product and stirring was continued for 30 minutes; the organic phase was then separated from the aqueous phase, washed with water, and then dried under vacuum and filtered.

[0080] Example 2 – Characterization of the monoester according to Example 1 The monoester obtained according to Example 1 was characterized in the following aspects: dynamic viscosity at -30°C according to ISO 3219, flash point according to ASTM D7094-04, pour point according to ASTM D5950, and volume resistivity at 25°C according to ASTM D1169.

[0081] In addition, the monoester was characterized in terms of thermal conductivity, thermal diffusivity and specific heat.

[0082] The analysis was performed according to ASTM D7896-19 using the transient hot wire method. The testing equipment was a Thermtest THW-L2; thermal conductivity and thermal diffusivity were measured at 40°C, and the specific heat was calculated as follows: Cp at 40°C = thermal conductivity at 40°C / (thermal diffusivity at 40°C * density at 40°C).

[0083] The results are reported in Table 1 below.

[0084] Table 1

[0085] Based on the comprehensive characterization of the monoesters developed and characterized for indirect cooling according to the above embodiments, it is clear that the fluids according to the invention exhibit very promising properties as an alternative solution to PFAS-based fluids. These monoesters exhibit remarkable characteristics, such as low viscosity at ultra-low temperatures, ensuring efficient flow and circulation even in demanding cooling applications. Furthermore, their high flash points improve safety metrics and reduce the risk of potential fire hazards.

[0086] Furthermore, these monoesters exhibit excellent volume resistivity and dielectric constant, ensuring optimal electrical insulation properties. In addition, their excellent thermal conductivity and heat transfer capacity enable effective heat dissipation, contributing to enhanced performance and reliability of electronic systems. Considering these advantageous properties, these monoesters represent a highly promising alternative to PFAS fluids in electronic device cooling applications.

[0087] In summary, these monoesters offer a more sustainable and environmentally friendly option compared to PFAS fluids, particularly in terms of greenhouse gas emissions. Their superior properties, coupled with reduced environmental impact, make them a highly advantageous alternative for cooling electronic devices.

Claims

1. The use of a heat transfer fluid for cooling electronic components in an indirect liquid cooling system, said heat transfer fluid comprising at least one C6-C 12 An aliphatic monohydric alcohol and at least one monoester of at least one straight-chain or branched C2-C7 aliphatic monocarboxylic acid.

2. The use according to claim 1, wherein in the heat transfer fluid, the C6-C of the monoester... 12 Aliphatic monohydric alcohols are selected from the group consisting of: 1-hexanol, 1-octanol, 2-ethylhexanol, isononol, 3,5,5-trimethylhexanol, 2-propylheptanol, 1-decanol, isodecanol (8-methyl-1-nonanol), isoundecanol (9-methyl-1-decanol), lauryl alcohol (dodecyl alcohol), 2,4-diethyloctanol, and mixtures thereof.

3. The use according to claim 1 or 2, wherein in the heat transfer fluid, the aliphatic monohydric alcohol of the monoester is C6-C. 10 Monohydric alcohol.

4. The use according to any one of claims 1 to 3, wherein in the heat transfer fluid, the aliphatic monohydric alcohol of the monoester is selected from the group consisting of 2-ethylhexanol, 2-propylheptanol, and mixtures thereof.

5. The use according to any one of claims 1 to 4, wherein in the heat transfer fluid, the aliphatic monocarboxylic acid of the monoester is a C5-C7 aliphatic monocarboxylic acid.

6. The use according to claim 5, wherein the C5-C7 aliphatic monocarboxylic acid is selected from the group consisting of 2-methylbutyric acid, 3-methylbutyric acid, valeric acid, hexanoic acid, heptanoic acid, and mixtures thereof.

7. The use according to any one of claims 1 to 6, wherein in the heat transfer fluid, the monoester is selected from the group consisting of 2-propylheptanol valerate and 2-ethylhexanol heptanate.

8. The use according to any one of claims 1 to 7, wherein the indirect liquid cooling system comprises at least one thermally conductive element thermally coupled to the electronic component, wherein the thermally conductive element is adapted to transfer heat from the electronic component to the heat transfer fluid.

9. The use according to claim 8, wherein the heat-conducting element is selected from the group consisting of: walls, layers, radiators, cold plates, heat pipes, and steam chambers.

10. The use according to any one of claims 1 to 9, wherein the indirect liquid cooling system comprises: A liquid cooling circuit adapted to circulate the heat transfer fluid; A pump adapted to pump the heat transfer fluid throughout the liquid cooling circuit; A heat exchanger adapted to cool the heat transfer fluid; and Optionally, a reservoir suitable for containing the heat transfer fluid.

11. The use according to any one of claims 1 to 10, wherein the electronic component is selected from the group consisting of: microprocessors, semiconductor wafers, power control semiconductors, electrochemical cells, power distribution switchgear, power transformers, circuit boards, multi-chip modules, hard disks, central processing units, packaged or unpackaged semiconductor devices, fuel cells, lasers, and semiconductor integrated circuits.

12. The use according to any one of claims 1 to 11, wherein the electronic component is installed in an electronic device.

13. The use according to claim 12, wherein the electronic device is selected from the group consisting of: computers, servers, server clusters, telecommunications centers, and data centers.

14. A method for cooling electronic components using an indirect liquid cooling system, wherein the liquid cooling system includes a heat transfer fluid comprising at least one C6-C 12 An aliphatic monohydric alcohol and at least one monoester of at least one straight-chain or branched C2-C7 aliphatic monocarboxylic acid.

15. The method of claim 14, wherein the method comprises the following steps: Heat is transferred from the electronic components to the heat transfer fluid.

16. The method of claim 14 or 15, wherein the heat transfer fluid is a heat transfer fluid as defined in any one of claims 1 to 7.

17. The method according to any one of claims 14 to 16, wherein the indirect liquid cooling system is the indirect liquid cooling system as defined in any one of claims 8 to 10.

18. The method of claim 17, wherein the indirect liquid cooling system includes at least one thermally conductive element thermally coupled to the electronic component, and wherein, in the heat transfer step, the thermally conductive material is adapted to transfer heat from the electronic component to the heat transfer fluid.

19. The method according to any one of claims 14 to 18, wherein the electronic component is the electronic component defined in any one of claims 11 to 13.

20. An electronic device comprising: At least one electronic component; and At least one indirect liquid cooling system, the indirect liquid cooling system being adapted to cool the electronic component and comprising at least one heat transfer fluid comprising at least one C6-C 12 An aliphatic monohydric alcohol and at least one monoester of at least one straight-chain or branched C2-C7 aliphatic monocarboxylic acid.

21. The electronic device of claim 20, wherein the heat transfer fluid is a heat transfer fluid as defined in any one of claims 1 to 7.

22. The electronic device according to claim 20 or 21, wherein the indirect liquid cooling system is an indirect liquid cooling system as defined in any one of claims 8 to 10.

23. The electronic device according to any one of claims 20 to 22, wherein the electronic device is selected from the group consisting of: computer, server, server cluster, telecommunications center, and data center.

24. The electronic device according to any one of claims 20 to 23, wherein the electronic component is an electronic component selected from the group consisting of: microprocessors, semiconductor wafers, power control semiconductors, electrochemical cells, power distribution switchgear, power transformers, circuit boards, multi-chip modules, hard disks, central processing units, packaged or unpackaged semiconductor devices, fuel cells, lasers, and semiconductor integrated circuits.

25. A heat transfer fluid for cooling electronic components, comprising at least one C6-C 12 The aliphatic monohydric alcohol and at least one monoester of at least one straight-chain or branched C2-C7 aliphatic monocarboxylic acid, and at least one additive, said additive being selected from the group consisting of: antioxidants, pour point depressants, defoamers, corrosion inhibitors, viscosity modifiers, abrasion-resistant and / or extreme pressure additives, friction modifiers, detergents, dispersants, and mixtures thereof.

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