Fluid for immersion cooling

Abstract

The present disclosure relates to a submerged cooling system comprising a housing having an interior space; the heating part is arranged in the internal space; and the working fluid liquid is arranged in the inner space, so that the heating component is in contact with the working fluid liquid. The working fluid comprises a compound having the structural formula (IA): each Rf1 and Rf2 is independently (i) a linear or branched, fully halogenated cycloalkyl-free group having 1 to 6 carbon atoms and optionally containing one or more catenated heteroatoms selected from O or N; or (ii) a fully halogenated 5-7 membered cyclic alkyl group having from 3 to 7 carbon atoms and optionally containing one or more catenated heteroatoms selected from O or N. The invention also relates to a method for producing the same.

Description

[0001] This application is a divisional application of patent application number "201880037428.X", filed on May 24, 2018, entitled "Fluid for Immersion Cooling". Technical Field

[0002] This disclosure relates to compositions that can be used in immersion cooling systems. Background Technology

[0003] Various fluids used in immersion cooling are described, for example, in PETuma's "Fluoroketone C2F5C(O)CF(CF3)2 as a Heat Transfer Fluid for Passive and Pumped 2‐Phase Applications," 24th IEEE Semi‐Therm Symposium, San Jose, CA, pp. 174–181, March 16–20, 2008; and in Tuma, PE's forthcoming "Design Considerations Relating to Non‐Thermal Aspects of Passive 2‐Phase Immersion Cooling," Proceedings of the 27th IEEE Semi‐Therm Symposium, San Jose, CA, pp. 174–181, March 16–20, 2011. Passive 2‐Phase Immersion Cooling,” to be published, Proc.27th IEEE Semi‐Therm Symposium, San Jose, CA, USA, Mar. 20‐24, 2011). Summary of the Invention

[0004] In some embodiments, an immersion cooling system is provided. The immersion cooling system includes a housing having an internal space; a heating element disposed within the internal space; and a working fluid disposed within the internal space such that the heating element is in contact with the working fluid. The working fluid comprises a compound having the structural formula (IA). (IA).

[0005] Each R f1 and R f 2 Independently, it is (i) a fully halogenated acyclic alkyl group having 1-6 carbon atoms and optionally containing one or more heteroatoms selected from O or N; or (ii) a fully halogenated 5-7 membered cyclic alkyl group having 3-7 carbon atoms and optionally containing one or more heteroatoms selected from O or N.

[0006] In some embodiments, a method for cooling a heat-generating component is provided. The method includes at least partially immersing the heat-generating component in a working fluid; and transferring heat from the heat-generating component using the working fluid. The working fluid comprises a compound having structural formula (IA). (IA).

[0007] Each R f 1 and R f 2 Independently, it is (i) a fully halogenated acyclic alkyl group having 1-6 carbon atoms and optionally containing one or more heteroatoms selected from O or N; or (ii) a fully halogenated 5-7 membered cyclic alkyl group having 3-7 carbon atoms and optionally containing one or more heteroatoms selected from O or N.

[0008] The above overview of this disclosure is not intended to describe every embodiment of this disclosure. Details of one or more embodiments of this disclosure are also set forth in the following description. Other features, objectives, and advantages of this disclosure will become apparent from the description and claims. Detailed Implementation

[0009] Large computer server systems can perform massive workloads and generate significant amounts of heat during operation. Much of this heat is generated by the operation of these servers. Partly due to the large amount of heat generated, these servers are typically rack-mounted and air-cooled via internal fans and / or fans attached to the back of the rack or other locations within the server ecosystem. As the need to access ever-increasing processing and storage resources continues to grow, the density of server systems (i.e., the amount of processing power and / or storage devices placed on a single server, the number of servers placed in a single rack, and / or the number of servers and / or racks deployed in a single server farm) continues to increase. The resulting thermal challenges remain significant obstacles due to the expectation of increasing processing or storage density in these server systems. Conventional cooling systems (e.g., fan-based) require substantial power, and the power costs required to drive such systems increase exponentially with increasing server density. Therefore, there is a need for efficient, low-power systems for cooling servers while allowing for the expected increases in processing and / or storage density.

[0010] Two-phase immersion cooling is a novel cooling technology for the high-performance server computing market that relies on the heat absorbed during the evaporation of a liquid (cooling fluid) into a gas (i.e., the heat of evaporation). The fluid used in this application must meet certain requirements to be feasible in the application. For example, the boiling temperature during operation should be in the range of, for example, 30°C–75°C. Generally, this range is suitable for keeping server components at a sufficiently cooled temperature while allowing heat to be efficiently dissipated to the final heat sink (e.g., outside air). The fluid must be inert, making it compatible with the materials and electronic components of the construction. Certain perfluorinated and partially fluorinated materials may meet this requirement. The fluid should be stable, such that it does not react with common contaminants such as water or with reagents such as activated carbon or alumina, which can be used to scrub the fluid during operation. The global warming potential (GWP, 100 yr ITH) and ozone depletion potential (ODP) of the parent compound and its degradation products should be below acceptable limits, for example, less than 250 and 0.01, respectively. The fluid should have a dielectric constant of less than 2.5 (measured at room temperature (approximately 25°C) at 1 kHz) so that high-frequency electronic components and connectors can be immersed in the fluid without significant loss of signal integrity.

[0011] Single-phase immersion cooling has a long history in computer server cooling. In single-phase immersion, there is no phase change. Instead, as the liquid flows or is pumped to the computer server and heat exchanger, it heats up and cools down, thus transferring heat away from the computer server. The fluid in single-phase immersion cooling for computer servers should meet the same requirements outlined above for two-phase immersion cooling, except that they typically have a higher boiling point of approximately 40-75°C to limit evaporation losses.

[0012] It is generally understood that perfluorinated liquids can exhibit a dielectric constant of 2.0 or less. However, these materials are often associated with high GWPs, well beyond the requirements of many industrial applications, including two-phase and single-phase immersion cooling. Therefore, there is a continued need for working fluids suitable for two-phase and single-phase immersion cooling that meet industrial dielectric constant requirements (less than 2.5) while exhibiting a GWP (100 yr ITH) below the industrial acceptable limits (typically less than about 250).

[0013] Generally speaking, this disclosure relates to compositions or working fluids that exhibit boiling point, reactivity, stability, GWP and dielectric constant that make them particularly suitable for use as cooling fluids in two-phase and single-phase immersion cooling systems.

[0014] As used herein, “heteroatom in chain” means an atom other than carbon (e.g., oxygen, nitrogen, or sulfur) that is bonded to at least two carbon atoms in a carbon chain (straight or branched or within a ring) to form a carbon-heteroatom-carbon chain.

[0015] As used herein, “fluorine-” (e.g., referring to a group or part, such as “fluoroalkylene” or “fluoroalkyl” or “fluorohydrocarbon”) or “fluorinated” means (i) partially fluorinated such that at least one hydrogen atom of a bonded carbon is present, or (ii) perfluorinated.

[0016] As used herein, “perfluorinated” (e.g., referring to a group or part, such as in the case of “perfluoroalkylene” or “perfluoroalkyl” or “perfluorohydrocarbon”) or “perfluorinated” means fully fluorinated such that, unless otherwise stated, any carbon-bonded hydrogen is replaced by a fluorine atom.

[0017] As used in this article, “fully halogenated” means fully halogenated, such that, unless otherwise specified, any carbon-bonded hydrogen is replaced by a halogen atom.

[0018] As used herein, the singular forms “a,” “an,” and “the” include plural references unless the context clearly indicates otherwise. As used in this specification and the appended embodiments, unless the context clearly indicates otherwise, the term “or” is generally used in its meaning including “and / or”.

[0019] As used herein, a range of values ​​expressed by endpoints includes all values ​​contained within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.8, 4, and 5).

[0020] Unless otherwise specified, all figures used in this specification and embodiments, including expressions or measurements of components, properties, etc., should in all cases be understood to be modified by the term "about". Therefore, unless stated to the contrary, the numerical parameters shown in the foregoing specification and the appended list of embodiments may vary according to the desired properties sought by those skilled in the art using the teachings of this disclosure. At a minimum, and without attempting to limit the application of the doctrine of equivalence to the embodiments protected by the claims, each numerical parameter should be interpreted at least according to the number of significant digits of the reported value and by applying customary rounding.

[0021] In some embodiments, the compositions disclosed herein may comprise a composition or working fluid comprising a hydrofluoroolefin compound having the following structural formula (IA): (IA) Surprisingly, the alkylene segments of structural formula (IA) (i.e., alkylene segments in which each carbon atom of the segment is bonded to a hydrogen atom and a fully halogenated portion of the E (or trans) configuration) have been found to provide a surprisingly low dielectric constant of less than 2.5. No other hydrofluoroolefin structures have been found to provide a similarly low dielectric constant. Therefore, the hydrofluoroolefin compounds of this disclosure have been found to have a measured dielectric constant that makes them particularly suitable for use as working fluids in immersion cooling systems, especially those used for immersion cooling of high-performance computer server hardware or equipment operating at high frequencies (e.g., greater than 2 GHz, or greater than 3 GHz, or greater than 4 GHz, or greater than 5 GHz, or greater than 6 GHz, or greater than 7 GHz, or greater than 8, or greater than 9, or greater than 10 GHz).

[0022] The hydrofluoroolefin compound of structural formula (IA) represents the E (or trans) isomer of the hydrofluoroolefin, which can exist in two isomeric forms, and the other isomer is the Z (or cis) isomer shown in structural formula (IB): (IB) Surprisingly, the (E) isomer (structural formula (IA)) has also been found to have a significantly lower dielectric constant than its (Z) counterpart, and therefore, compositions rich in the (Z) isomer do not exhibit a dielectric constant suitable for use as a working fluid in high-performance server immersion cooling systems.

[0023] In some implementations, each Rf 1 and R f 2 It can be independently (i) a fully halogenated acyclic alkyl group having 1-6, 2-5, or 3-4 carbon atoms and optionally containing one or more in-chain heteroatoms selected from O or N; or (ii) a fully halogenated 5-7 membered cyclic alkyl group having 3-7 or 4-6 carbon atoms and optionally containing one or more in-chain heteroatoms selected from O or N. In some embodiments, each fully halogenated R f 1 and R f 2 It can be substituted by either fluorine or chlorine atoms. In some embodiments, each fully halogenated R... f 1 and R f 2 It can be replaced by only a fluorine atom and a chlorine atom.

[0024] In some implementations, each R f 1 and R f 2 It can be independently (i) a straight-chain or branched perfluorinated acyclic alkyl group having 1-6, 2-5, or 3-4 carbon atoms and optionally containing one or more in-chain heteroatoms selected from O or N; or (ii) a perfluorinated 5-7 membered cyclic alkyl group having 3-7 or 4-6 carbon atoms and optionally containing one or more in-chain heteroatoms selected from O or N. In some embodiments, R f 1 and R f 2 It can be the same perfluorinated alkyl group (acyclic or cyclic, including any heteroatoms in the chain).

[0025] In some embodiments, the compositions of this disclosure may be rich in the isomer (E isomer) of structural formula (IA). In this regard, in some embodiments, the compositions of this disclosure may contain at least 85% by weight, 90% by weight, 95% by weight, 96% by weight, 97% by weight, 98% by weight, 99% by weight, or 99.5% by weight of hydrofluoroolefin having structural formula (IA) based on the total weight of hydrofluoroolefins having structural formulas (IA) and (IB) in the composition.

[0026] Representative examples of compounds of general formula (I) in various embodiments include the following compounds: In some embodiments, the hydrofluoroolefin compounds of this disclosure may be hydrophobic, relatively chemically inert, and thermally stable. Such hydrofluoroolefin compounds may have a low environmental impact. In this respect, the hydrofluoroolefin compounds of this disclosure may have zero or near-zero ozone depletion potential (ODP) and a global warming potential (GWP, 100 yr ITH) of less than 500, 300, 200, 100, or less than 10. As used herein, GWP is a relative measure of the global warming potential of a compound based on its structure. The GWP of a compound, defined by the Intergovernmental Panel on Climate Change (IPCC) in 1990 and updated in 2007, is calculated as the warming effect caused by the release of 1 kg of the compound relative to the warming effect caused by the release of 1 kg of CO2 over a specified integral time period (ITH).

[0027] In this formula, a i Let C be the radiative forcing per unit mass of the compound in the atmosphere (the change in the radiative flux through the atmosphere due to the compound's IR absorption), τ be the atmospheric concentration of the compound, t be the atmospheric lifetime of the compound, and t be time. i For compounds of interest. The generally accepted ITH is 100 years, representing a trade-off between short-term (20 years) and long-term (500 years or more) effects. This assumes organic compounds in the atmosphere. i The concentration of CO2 follows a pseudo-first-order kinetic (i.e., exponential decay). The CO2 concentration over the same time interval is modeled using a more complex model of CO2 exchange and removal from the atmosphere (the Bern carbon cycle model).

[0028] In some embodiments, the fluorine content in the hydrofluoroolefin compounds of this disclosure may be sufficient to render the compounds non-flammable, according to the ASTM D-3278-96 e-1 test method (“Flash Point of Liquids by Small Scale Closed Cup Apparatus”).

[0029] In some embodiments, the hydrofluoroolefin compound represented by structural formula (IA) can be synthesized by the methods described in WO2009079525, WO 2015095285, US8148584, J. Fluorochemistry (24th edition, 1984, pp. 93-104) and WO2016196240.

[0030] In some embodiments, the compositions or working fluids disclosed herein may contain at least 25% by weight, at least 50% by weight, at least 70% by weight, at least 80% by weight, at least 90% by weight, at least 95% by weight, or at least 99% by weight of the aforementioned hydrofluoroolefins based on the total weight of the composition. In addition to hydrofluoroolefins, the composition may, based on the total weight of the working fluid, comprise one or more of the following components (alone or in any combination): ethers, alkanes, perfluoroolefins, olefins, halogenated olefins, perfluorocarbons, perfluorinated tertiary amines, perfluorinated ethers, cycloalkanes, esters, perfluorinated ketones, ketones, ethylene oxide, aromatic compounds, siloxanes, hydrochlorocarbons, hydrochlorofluorocarbons, hydrofluorocarbons, hydrofluoroolefins, hydrochlorofluoroolefins, hydrofluoroethers, or mixtures thereof; or, based on the total weight of the working fluid, alkanes, perfluoroolefins, halogenated olefins, perfluorocarbons, perfluorinated tertiary amines, perfluorinated ethers, cycloalkanes, perfluorinated ketones, aromatic compounds, siloxanes, hydrochlorocarbons, hydrochlorofluorocarbons, hydrofluorocarbons, hydrofluoroolefins, hydrochlorofluoroolefins, hydrofluoroethers, or mixtures thereof. Such additional components can be selected to modify or enhance the properties of compositions intended for a specific purpose.

[0031] In some embodiments, as measured at room temperature according to ASTM D150, the compositions or working fluids of this disclosure may have a dielectric constant of less than 2.5, less than 2.4, less than 2.3, less than 2.2, less than 2.1, less than 2.0, or less than 1.9.

[0032] In some embodiments, the compositions or working fluids of this disclosure may have a boiling point between 30-75°C, or 35-75°C, 40-75°C, or 45-75°C. In some embodiments, the compositions or working fluids of the present invention may have a boiling point greater than 40°C, or greater than 50°C, or greater than 60°C, greater than 70°C, or greater than 75°C.

[0033] In some embodiments, this disclosure may relate to an immersion cooling system comprising the aforementioned hydrofluoroolefin-containing working fluid. The immersion cooling system may be a single-phase or two-phase immersion cooling system.

[0034] In some implementations, the immersion cooling system can operate as a two-phase evaporative-condensation cooling system for cooling one or more heat-generating components. For example... Figure 1As shown, in some embodiments, the two-phase immersion cooling system 10 may include a housing 10 having an internal space 15. Within the lower volume 15A of the internal space 15, a liquid phase 20 of a hydrofluoroolefin-containing working fluid may be disposed, the working fluid having an upper liquid surface 20A (i.e., the highest liquid level of the liquid phase 20). The internal space 15 may also include an upper volume 15B extending upward from the liquid surface 20A to the upper portion 10A of the housing 10.

[0035] In some embodiments, the heating element 25 may be disposed within the internal space 15 such that it is at least partially immersed (and at most fully immersed) in the liquid phase 20 of the working fluid. That is, although the heating element 25 is shown as being only partially immersed below the upper liquid surface 20A, in some embodiments, the heating element 25 may be completely immersed below the liquid surface 20A. In some embodiments, the heating element may include one or more electronic devices, such as a computing server.

[0036] In various embodiments, a heat exchanger 30 (e.g., a condenser) may be disposed within the upper volume 15B. Generally, the heat exchanger 30 may be configured to condense the vapor phase 20B of the working fluid, which is generated by heat generated by the heating element 25. For example, the heat exchanger 30 may have an outer surface that is maintained at a temperature below the condensation temperature of the vapor phase of the working fluid. In this respect, at the heat exchanger 30, when the rising vapor phase 20B comes into contact with the heat exchanger 30, the rising vapor phase 20B of the working fluid can be condensed back into the liquid phase or condensate 20C by releasing latent heat to the heat exchanger 30. The resulting condensate 20C can then be returned to the liquid phase 20 disposed in the lower volume 15A.

[0037] In some embodiments, this disclosure may relate to an immersion cooling system operating via single-phase immersion cooling. Generally, a single-phase immersion cooling system is similar to a two-phase system because it may include a heating element disposed within the internal space of a housing, such that it is at least partially immersed (and at most fully immersed) in the liquid phase of a working fluid. The single-phase system may also include a pump and a heat exchanger, the pump operating to move and remove the working fluid from the heating element and heat exchanger, and the heat exchanger operating to cool the working fluid. The heat exchanger may be disposed within or outside the housing.

[0038] While this disclosure describes examples of suitable two-phase and single-phase immersion cooling systems, it should be understood that the beneficial effects and advantages of the hydrofluoroolefin-containing working fluid of this disclosure can be achieved in any known two-phase or single-phase immersion cooling system.

[0039] In some embodiments, this disclosure may relate to methods for cooling electronic components. Generally, the method may include at least partially immersing a heat-generating component (e.g., a computer server) in a liquid containing the aforementioned olefin compound or working fluid. The method may also include using the aforementioned olefin compound or working fluid to transfer heat from the heat-generating component.

[0040] List of implementation plans 1. An immersion cooling system, comprising: A housing having an internal space; A heating element, wherein the heating element is disposed within the internal space; The working fluid within the internal space is positioned such that the heating element is in contact with the working fluid. The working fluid contains a compound having the structural formula (IA). (IA) Each R f 1 and R f 2 Independently, it is (i) a fully halogenated acyclic alkyl group having 1-6 carbon atoms and optionally containing one or more heteroatoms selected from O or N; or (ii) a fully halogenated 5-7 membered cyclic alkyl group having 3-7 carbon atoms and optionally containing one or more heteroatoms selected from O or N.

[0041] 2. The immersion cooling system according to embodiment 1, wherein each R f 1 and R f 2 Independently, it is (i) a straight-chain or branched perfluorinated acyclic alkyl group having 1-6 carbon atoms and optionally containing one or more heteroatoms selected from O or N; or (ii) a perfluorinated 5-7 membered cyclic alkyl group having 3-7 carbon atoms and optionally containing one or more heteroatoms selected from O or N.

[0042] 3. The immersion cooling system according to implementation scheme 2, wherein R f 1 and R f 2 They are the same perfluorinated alkyl groups.

[0043] 4. The immersion cooling system according to any one of embodiments 1-3, wherein, based on the total weight of the compound having structural formula (IA) and the compound having structural formula (IB) in the working fluid, the compound having structural formula (IA) is present in an amount of at least 90% by weight. (IB) In the working fluid.

[0044] 5. The immersion cooling system according to any one of embodiments 1-4, wherein the compound having structural formula (IA) is present in the working fluid in an amount of at least 50% by weight, based on the total weight of the working fluid.

[0045] 6. The immersion cooling system according to any one of embodiments 1-5, wherein the working fluid has a dielectric constant of less than 2.5.

[0046] 7. The immersion cooling system according to any one of embodiments 1-6, wherein the working fluid has a boiling point of 30-75°C.

[0047] 8. The immersion cooling system according to any one of embodiments 1-7, wherein the working fluid has a boiling point greater than 75°C.

[0048] 9. The immersion cooling system according to any one of embodiments 1-8, wherein the heat-generating component includes electronic equipment.

[0049] 10. The immersion cooling system according to embodiment 9, wherein the electronic equipment includes a computing server.

[0050] 11. The immersion cooling system according to embodiment 10, wherein the computing server operates at a frequency greater than 3 GHz.

[0051] 12. The immersion cooling system according to any one of embodiments 1-11, wherein the immersion cooling system further comprises a heat exchanger disposed within the system such that the working fluid vapor contacts the heat exchanger when the working fluid liquid evaporates; 13. The immersion cooling system according to any one of embodiments 1-12, wherein the immersion cooling system comprises a two-phase immersion cooling system.

[0052] 14. The immersion cooling system according to any one of embodiments 1-11, wherein the immersion cooling system comprises a single-phase immersion cooling system.

[0053] 15. An immersion cooling system according to any one of embodiments 1-11 or 14, wherein the immersion cooling system further comprises a pump configured to move the working fluid to and from the heat exchanger.

[0054] The operation of this disclosure will be further described with reference to the embodiments detailed below. These embodiments are provided to further illustrate various implementations and techniques. However, it should be understood that many variations and modifications can be made while still falling within the scope of this disclosure.

[0055] This application includes the following items: 1. An immersion cooling system, comprising: A housing having an internal space; A heating element, wherein the heating element is disposed within the internal space; and A working fluid is disposed within the internal space, such that the heating element is in contact with the working fluid. The working fluid contains a compound having the structural formula (IA). (IA) Each R f 1 and R f 2 Independently, it is (i) a fully halogenated acyclic alkyl group having 1-6 carbon atoms and optionally containing one or more heteroatoms selected from O or N; or (ii) a fully halogenated 5-7 membered cyclic alkyl group having 3-7 carbon atoms and optionally containing one or more heteroatoms selected from O or N.

[0056] 2. The immersion cooling system according to Project 1, wherein each R f 1 and R f 2 Independently, it is (i) a straight-chain or branched perfluorinated acyclic alkyl group having 1-6 carbon atoms and optionally containing one or more heteroatoms selected from O or N; or (ii) a perfluorinated 5-7 membered cyclic alkyl group having 3-7 carbon atoms and optionally containing one or more heteroatoms selected from O or N.

[0057] 3. The immersion cooling system according to Project 2, wherein R f 1 and R f 2 They are the same perfluorinated alkyl groups.

[0058] 4. The immersion cooling system according to Project 1, wherein the weight of the compound having structural formula (IA) and the compound having structural formula (IB) in the working fluid is used as the basis for measurement. (IB) The compound having structural formula (IA) is present in the working fluid in an amount of at least 90% by weight.

[0059] 5. The immersion cooling system according to Project 1, wherein the compound having structural formula (IA) is present in the working fluid in an amount of at least 50% by weight, based on the total weight of the working fluid.

[0060] 6. The immersion cooling system according to Project 1, wherein the working fluid has a dielectric constant of less than 2.5.

[0061] 7. The immersion cooling system according to Project 1, wherein the working fluid has a boiling point of 30-75°C.

[0062] 8. The immersion cooling system according to any one of Project 1, wherein the working fluid has a boiling point greater than 75°C.

[0063] 9. The immersion cooling system according to Item 1, wherein the heat-generating component includes electronic equipment.

[0064] 10. The immersion cooling system according to item 9, wherein the electronic equipment includes a computing server.

[0065] 11. The immersion cooling system according to Item 10, wherein the computing server operates at a frequency greater than 3 GHz.

[0066] 12. The immersion cooling system according to Item 1, wherein the immersion cooling system further includes a heat exchanger disposed within the system such that, when the working fluid liquid evaporates, the working fluid vapor contacts the heat exchanger.

[0067] 13. The immersion cooling system according to Item 1, wherein the immersion cooling system includes a two-phase immersion cooling system.

[0068] 14. The immersion cooling system according to any one of items 1, wherein the immersion cooling system includes a single-phase immersion cooling system.

[0069] 15. The immersion cooling system according to Item 1, wherein the immersion cooling system further includes a pump configured to move the working fluid to and from the heat exchanger.

[0070] 16. A method for cooling a heat-generating component, the method comprising: The heating element is at least partially immersed in the working fluid; and Heat is transferred from the heating element using the working fluid; The working fluid contains a compound having the structural formula (IA). (IA) Each R f 1 and R f 2 Independently, it is (i) a fully halogenated acyclic alkyl group having 1-6 carbon atoms and optionally containing one or more heteroatoms selected from O or N; or (ii) a fully halogenated 5-7 membered cyclic alkyl group having 3-7 carbon atoms and optionally containing one or more heteroatoms selected from O or N.

[0071] Example This disclosure is described in more detail in the following embodiments, which are intended to be illustrative only, as many modifications and variations within the scope of this disclosure will be apparent to those skilled in the art. Unless otherwise specified, all parts, percentages, and ratios mentioned in the following embodiments are by weight. Unless otherwise specified, the reagents were purchased from Sigma Aldrich Company, St. Louis, MO, USA.

[0072] Examples 1, 3 and 4, as well as comparative examples CE2, CE3 and CE4, were purchased from Synquest Laboratories in Araquía, Florida, USA, and used as is.

[0073] To prepare Example 2, antimony pentafluoride (30 g, 138.41 mmol) was charged into a 600 mL Parr reactor. The reactor was sealed and cooled on dry ice. A vacuum was then applied while the reactor was cooling. 1,1-Difluoro-N-(trifluoromethyl)methaneamine (205 g, 1541.1 mmol, prepared by decarboxylation of di(trifluoromethyl)aminofluoride, which can be prepared by electrochemical fluorination of dimethylformamide) and (E)-1,3,3,3-tetrafluoroprop-1-ene (240 g, 2104.5 mmol, purchased from Honeywell) were then sequentially charged as liquids into the top space of the reactor. The reactor was then placed in a base, stirred, and allowed to heat to room temperature. Once at room temperature, the heat on the reactor was gradually increased to 70°C. After maintaining this temperature for 16 hours, the reactor was cooled, vented, and poured onto ice. The weight of the recovered crude fluorinated compound product was 138 g. According to GC analysis, approximately 68% of the total recovered mass was the desired product. The material was subsequently purified by fractionation, and the structure was confirmed by GC / MS and F19 and H1 NMR to be the (E) isomer of 3,3,3-trifluoro-N,N-di(trifluoromethyl)prop-1-en-1-amine.

[0074] To prepare Comparative Example CE1, sodium borohydride (5.23 g, 138 mmol) and diethylene glycol dimethyl ether (102 g) were charged into a 1 L three-necked round-bottom flask equipped with a top-mounted stirrer, thermocouple, chilled water condenser, dry N2 wire, and feeding funnel. The mixture was stirred to dissolve some of the borohydride. The mixture was then cooled to -72 °C, and 1,1,1,3,4,4,5,5,5-nonafluoro-2-(trifluoromethyl)pent-2-ene (103 g, 343.285 mmol) was added dropwise through the feeding funnel with stirring, while maintaining the temperature between -72 °C and -63 °C. Once the addition was complete, the batch was stirred at -72 °C for another hour. The reaction mixture was then heated to 15 °C and quenched with 10 g of water and 400 g of 35% H3PO4. The reaction mixture was transferred to a separatory funnel, and 90 g of the product was collected. GC-MS results showed that the crude product mainly consisted of monohydrides and dihydrides. Further purification of the desired monohydride was achieved by fractional distillation, yielding the pure material. The boiling point of the material was 52 °C. The structure was confirmed by GC / MS, as well as F19 and H1 NMR.

[0075] The dielectric constant was determined using ASTM D150 at room temperature, and the average value at 1 kHz was reported.

[0076] While specific implementation schemes have been illustrated and described herein for the purpose of illustrating certain implementation schemes, those skilled in the art should understand that various alternative and / or equivalent implementation schemes may be used in place of the illustrated and described schemes without departing from the scope of this disclosure.

Claims

1. An immersion cooling system comprising: a housing having an interior space; a heat-generating component disposed within the interior space; and a working fluid liquid disposed within the interior space such that the heat- generating component is in contact with the working fluid liquid; wherein the working fluid comprises a compound having structural formula (IA) wherein the working fluid has a dielectric constant of less than 2.5; and (I) wherein each R f 1 and R f 2 independently (i) a straight chain or branched chain perhalogenated acyclic alkyl group having 1-6 carbon atoms and optionally containing one or more catenary heteroatoms selected from O or N; or (ii) a perhalogenated 5-7 membered cyclic alkyl group having 3-7 carbon atoms and optionally containing one or more catenary heteroatoms selected from O or N; wherein the heat-generating component comprises an electronic device.

3. The immersion cooling system of claim 1, wherein, based on the total weight of the compound having structural formula (IA) and a compound having structural formula (IB) in the working fluid, 2. The immersion cooling system of claim 1, wherein each R f 1 and R f 2 is independently (i) a linear or branched perfluorinated acyclic alkyl group having 1-6 carbon atoms and optionally containing one or more catenary heteroatoms selected from O or N; or (ii) a perfluorinated 5-7 membered cyclic alkyl group having 3-7 carbon atoms and optionally containing one or more catenary heteroatoms selected from O or N. the compound having structural formula (IA) is present in the working fluid in an amount of at least 90% by weight. (IB) 4. A method for cooling a heat-generating component, the method comprising: at least partially immersing a heat-generating component in a working fluid; and using the working fluid to transfer heat from the heat-generating component; wherein the working fluid comprises a compound having structural formula (IA) wherein the working fluid has a dielectric constant of less than 2.5; and wherein the heat-generating component comprises an electronic device. (I) (IA) wherein each R f 1 and R f 2 independently (i) a straight chain or branched chain perhalogenated alkyl group having from 1 to 6 carbon atoms and optionally containing one or more catenary heteroatoms selected from O or N; or (ii) a perhalogenated 5- to 7-membered cyclic alkyl group having from 3 to 7 carbon atoms and optionally containing one or more catenary heteroatoms selected from O or N; ​ ​

Images