HEAT TRANSFER METHODS, SYSTEMS AND FLUIDS

FIELD

[0001] The present invention relates to methods and systems for removing heat from and/or adding heat to operating electronic devices and systems, to thermal management of such operating electronic devices and systems, and to other high temperature heat transfer applications like secondary loop systems, organic Rankine cycle (“ORC”) applications, and high temperature heat pumps.

BACKGROUND

[0002] Heat dissipation is becoming an increasingly challenging issue in many applications. In portable and hand-held electronic devices, for example, the desire to miniaturize while adding functionality increases the thermal power density of the device while in operation, thus making cooling of the electronics components, including the batteries, within them more challenging. As computational power increases within desktop computers, datacenters and telecommunications centers, so too does the heat output, again making thermal management of such electronic devices increasingly important. The acceleration of electrification of mobility also presents new challenges for thermal management (e.g., cabin, battery in electric vehicles). In electronic vehicles the thermal management function is especially important for several reasons, including the criticality of cooling the batteries within a relatively narrow temperature range and in a way that is reliable, efficient and safe. The challenge to provide effective thermal battery management is becoming greater as the demand for battery-operated vehicles with greater range and faster charging increases.

[0003] The efficiency and effectiveness of batteries, especially the batteries that provide the power in electronic vehicles, is a function of the operating temperature at which they operate. Thus, a thermal management system must frequently be able to do more than simply remove heat from the battery during operation and/or charging - it must be able to effect cooling in a relatively narrow temperature range using equipment that is as low cost as possible and as light weight as possible. This results in the need for a heat transfer fluid in such systems that possesses a difficult-to-achieve combination of physical and performance properties. Furthermore, in some important applications the thermal management system must be able to add heat to the battery, especially as the vehicle is started in cold weather, which adds further difficulty to the selection of heat transfer fluids for use in such systems.

[0004] One frequently used system for the thermal management of electronic vehicle batteries involves immersing the battery in the fluid used for thermal management. Such systems add the additional constraint that the fluid used in such systems must be

electronically compatible with the intimate contact with the battery, or other electronic device, while the battery or device is in operation. In general, this means the fluid must not only be non-flammable, it must also have a low electrical conductivity and a high level of stability while in contact with the battery or other electronic component while the component is operating and at the relatively high temperatures existing during operation. Applicants have come to appreciate the desirability of such properties even in indirect cooling of operating electronic devices and batteries because leakage of any such fluid may result in contact with operating electronic components.

[0005] The thermal management fluid which has been commonly used for battery cooling, including immersive cooling, is a water/glycol combination, although other classes of materials, including chlorofluorocarbons, fluorohydrocarbons, chlorohydrocarbons and hydrofluoroethers, have been mentioned for possible use. See, for example, US

2018/0191038.

[0006] While many fluids comprising compounds in the above-noted classes, including fluorohydrocarbons, have been used or suggested for use as refrigerants generally, those skilled in the art of thermal management of operating electronic devices will appreciate that many, if not most, of the fluorohydrocarbons will not satisfy the fully compliment of desirable properties to be effective for use in cooling of operating electronic systems, especially for immersive cooling techniques. For example, US 5,026,499 discloses an azeotrope composition comprising fluid comprising 21-27 wt.% of 1-trifluoromethyl-1 ,2,2-trifluorocyclobutane (TFMCB), 64-72 wt.% trans dichloroethylene and 5 -11 wt.% methanol and suggests that such a fluid generally for a solvent, an aerosol, a blowing agent and a refrigerant. However, there is no disclosure in US 5,026,499 mentioning or suggesting use of such an zeotropic composition in the specialized methods and systems according to the present invention, as describe in more detail hereinafter.

[0007] Thus, applicants have come to appreciate the need for thermal management methods and systems which use a heat transfer fluid which is environmentally acceptable, non-flammable, has low or no toxicity, has excellent insulating properties and has thermal properties that provide effect cooling and/or heat of operating electronic components in a relatively narrow temperature range with equipment that is low cost, reliable and light weight. Thus, for example, applicants have found that fluids that have relatively low boiling points (e.g., below 50oC) are not desirable in many applications since the use of such fluids will tend to increase the cost and/or weight of the cooling equipment for many battery and/or electronic cooling applications, and may also decrease reliability, as explained hereinafter.

[0008] The Rankine cycle is the standard thermodynamic cycle in general use for electric power generation. The essential elements of a Rankine cycle system are: 1) a boiler to change liquid to vapor at high pressure; 2) a turbine to expand the vapor to derive mechanical energy; 3) a condenser to change low pressure exhaust vapor from the turbine to low pressure liquid; and 4) a pump to move condensate liquid back to the boiler at high pressure.

[0009] Various working fluids have been suggested as working fluids in Rankine cycles, including HFC-245fa. However, there is a desire in the industry to provide a working fluid which is environmentally acceptable, has excellent thermodynamic properties, and can operate efficiently over a wide range of heat source temperatures, including, for example, at least about 200°C, for example of from about 200°C to about 400°C.

[0010] There is also a desire in the industry to provide a heat transfer fluid (e.g. a refrigerant) which is environmentally acceptable, has excellent thermodynamic properties, and is non-flammable.

SUMMARY

[0011] The present invention includes methods for removing heat from an article, device or fluid comprising:

(a) providing a high temperature heat source; and

(b) removing heat from said high temperature heat source by evaporating at a temperature greater than about 50°C, greater than about 55°C, or greater than about 60°C, a heat transfer fluid comprising, consisting essentially of, or consisting of 1-trifluoromethyl- 1 ,2,2-trifluorocyclobutane (TFMCB).

[0012] The present invention includes methods for removing heat from an article, device or fluid comprising:

(a) providing a high temperature heat source; and

(b) removing heat from said high temperature heat source by evaporating a heat transfer fluid comprising at least about 50% by weight of TFMCB.

[0013] The present invention includes methods for removing heat from an article, device or fluid comprising:

(a) providing a high temperature heat source; and

(b) removing heat from said high temperature heat source by evaporating at a temperature greater than about 50°C, greater than about 55°C, or greater than about 60°C, a heat transfer fluid comprising at least about 50% by weight of TFMCB.

[0014] The present invention includes methods for removing heat from an article, device or fluid comprising:

(a) providing a high temperature heat source; and

(b) removing heat from said high temperature heat source by evaporating at a temperature greater than about 50°C, greater than about 55°C, or greater than about 60°C, a heat transfer fluid consisting essentially of TFMCB.

[0015] The present invention includes methods for removing heat from an article, device or fluid comprising:

(a) providing a high temperature heat source; and

(b) removing heat from said high temperature heat source by evaporating at a temperature greater than about 50°C, greater than about 55°C, or greater than about 60°C, a heat transfer fluid consisting of TFMCB.

[0016] The present invention includes methods for removing heat from an article, device or fluid comprising:

(a) providing a high temperature heat source; and

(b) removing heat from said high temperature heat source by adding sensible heat to a heat transfer liquid at a temperature greater than about 50°C, greater than about 55°C, or greater than about 60°C, said heat transfer liquid comprising, consisting essentially of, or consisting of 1-trifluoromethyl-1 ,2,2-trifluorocyclobutane (TFMCB).

[0017] The present invention includes methods for removing heat from an article, device or fluid comprising:

(a) providing a high temperature heat source; and

(b) removing heat from said high temperature heat source by adding sensible heat to a heat transfer liquid comprising at least about 50% by weight of 1-trifluoromethyl-1 ,2,2-trifluorocyclobutane (TFMCB).

[0018] The present invention includes methods for removing heat from an article, device or fluid comprising:

(a) providing a high temperature heat source; and

(b) removing heat from said high temperature heat source by evaporating at a temperature greater than about 50°C, greater than about 55°C, or greater than about 60°C, a heat transfer fluid comprising at least about 50% by weight of 1-trifluoromethyl-1 ,2,2-trifluorocyclobutane (TFMCB).

[0019] The present invention includes methods for removing heat from an article, device or fluid comprising:

(a) providing a high temperature heat source; and

(b) removing heat from said high temperature heat source by adding sensible heat to a heat transfer liquid at a temperature greater than about 50°C, greater than about 55°C, or greater than about 60°C, said heat transfer liquid consisting essentially of 1-trifluoromethyl- 1 ,2,2-trifluorocyclobutane (TFMCB).

[0020] The present invention includes methods for removing heat from an article, device or fluid comprising:

(a) providing a high temperature heat source; and

(b) removing heat from said high temperature heat source by adding sensible heat to a heat transfer liquid at a temperature greater than about 50°C, greater than about 55°C, or greater than about 60°C, said heat transfer liquid being non-flammable and consisting essentially of 1-trifluoromethyl-1 ,2,2-trifluorocyclobutane (TFMCB) and having a dielectric constant of less than 30 (<30) and an electrical conductivity of less than 15 nS/cm (<15 nS/cm).

[0021] The present invention includes methods for removing heat from an article, device or fluid comprising:

(a) providing a high temperature heat source; and

(b) removing heat from said high temperature heat source by evaporating at a temperature greater than about 50°C, greater than about 55°C, or greater than about 60°C, a non-flammable heat transfer fluid consisting essentially of TFMCB and having a dielectric constant of less than 30 (<30) and an electrical conductivity of less than 15 nS/cm (<15 nS/cm).

[0022] The present invention also includes methods for removing heat from, and optionally adding heat to, an operating electronic device, including particularly a battery, comprising:

(a) generating heat by operating said electronic device; and

(b) removing at least a portion of said generated heat of operation by transferring said heat to a heat transfer fluid comprising, consisting essentially of, or consisting of TFMCB.

[0023] As used herein, the term“operating electronic device,” and related word forms means a device, or a component of a device, which is in the process of performing its intended function by receiving, and/or transmitting and/or producing electrical energy and/or electronic signals. Thus, the term“operating electronic device” as used herein includes, for example, a battery which is in the process of providing a source of electrical energy to another component and also a battery which is being charged or recharged.

[0024] The present invention also includes methods for removing heat from, and optionally adding heat to, an operating electronic device comprising:

(a) generating heat by operating said electronic device; and

(b) maintaining said operating electronic device immersed in a heat transfer fluid comprising, consisting essentially of, or consisting of TFMCB.

[0025] The present invention also includes methods for thermally regulating the temperature of battery comprising:

(a) providing the battery in thermal contact with a heat transfer fluid comprising, consisting essentially of, or consisting of TFMCB;

(b) providing a secondary fluid or an article other than said battery for removing heat from said heat transfer fluid; and

(c) providing a secondary fluid or article other than said battery for adding heat to said heat transfer fluid, wherein said secondary fluid or article of step (b) may be the same or different than the secondary fluid or article of step (c).

[0026] The present invention also includes a thermally regulated battery comprising:

(a) a surface of the battery which will contain at least a portion of the heat generated by the battery during operation;

(b) a heat transfer fluid in thermal contact with said surface, said heat transfer fluid comprising, consisting essentially of, or consisting of TFMCB.

[0027] As used herein, the term“thermal contact,” and related forms thereof includes direct contact with the surface and indirect contact though another body or fluid which facilitates the flow of heat between the surface and the fluid.

[0028] Applicants have unexpectedly discovered that TFMCB not only meets the challenging performance requirements for high temperature heat transfer applications and for electronic cooling but also satisfies exacting environmental and safety requirements. Specifically, applicants discovered that TFMCB is non-flammable (and has no flash point below 100°F), has low toxicity, an ODP of < 0.01 and a GWP of 44, and is dielectric and electrically stable. In particular, applicants have determined that TFMCB has a measured dielectric constant of 20 at 22°C as determined by ASTM D2477-07 and has a measured electrical conductivity of less than 10 nS/cm at 22°C as determined by ASTM D 2624.

[0029] The present invention includes also heat transfer compositions comprising at least about 50% by weight of, and consisting essentially of, TFMCB and at least one co-heat transfer fluid component that does not lower the boiling point below about 50°C, below about 55°C, or below about 60°C.

[0030] The present invention includes also heat transfer compositions comprising at least about 50% by weight of, or consisting essentially of, TFMCB and at least one co-heat transfer fluid component that does not lower the boiling point below about 50°C, below about 55°C, or below about 60°C and which does not raise the electrical conductivity of the heat transfer composition above 15 nS/cm at 22°C.

[0031] The present invention includes also heat transfer compositions comprising at least about 50% by weight of, or consisting essentially of, TFMCB and at least one co-heat transfer fluid component that does not lower the boiling point below about 50°C, below about 55°C, or below about 60°C and which does not result in a dielectric constant for the heat transfer composition that is below about 30.

[0032] The present invention includes also heat transfer compositions comprising at least about 50% by weight of, or consisting essentially of, TFMCB and at least one co-heat transfer fluid component that does not make the heat transfer composition flammable.

[0033] The present invention includes also heat transfer compositions comprising at least about 50% by weight of, or consisting essentially of, TFMCB and at least one co-heat transfer fluid component that does not make the heat transfer composition toxic.

[0034] The present invention includes also heat transfer compositions comprising at least about 50% by weight of, or consisting essentially of, TFMCB and at least one co-heat transfer fluid component, provided that said at least one co-heat transfer component is of a type and present in an amount that does not: (i) lower the boiling point of the heat transfer fluid below about 50°C, below about 55°C, or below about 60°C; or (ii) result in a dielectric constant for the heat transfer composition that is below about 30; or (iii) make the heat transfer composition flammable; or (iv) make the heat transfer composition toxic. Applicants believe that, in view of the teachings contained herein, the selection of the co-heat transfer fluid and the amount thereof can be made by those skilled in the art without undue experimentation.

[0035] For example, the heat transfer fluid of the present invention may additionally include at least one co-heat transfer component selected from the group consisting of HFE-7000, HFE-7200, HFE-7100, HFE-7300, HFE-7500, HFE-7600, trans-1 ,2-dichloroethylene, n-pentane, cyclopentane, methanol, ethanol, perfluoro(2-methyl-3-pentanone), cis-HFO-1336mzz, trans-HFO-1336mzz, HF-1234yf, HFO-1234ze(E), HFO-1233zd(E), and HFO-1233zd(Z).

[0036] The heat transfer may have a Global Warming Potential (GWP) of not greater than about 1000.

[0037] The heat transfer fluid may be a class 1 refrigerant, a class A refrigerant, or a class A1 refrigerant.

[0038] The heat transfer fluid may have a flash point of greater than about 100°F (37.8 °C).

[0039] The invention further discloses a heat transfer composition comprising the heat transfer fluid and a lubricant. The lubricant may be present in an amount from about 5% to about 30% by weight of heat transfer fluid. The lubricant may include at least one lubricant selected from the group consisting of polyol esters (POEs), poly alkylene glycols (PAGs), polyalkylene glycol oils, polyvinyl ethers (PVEs), and poly(alpha-olefin)s (PAOs). The lubricant may include at least one polyol ester (POE).

[0040] An electronic device may include the heat transfer fluid, and a method of heating or cooling may use the heat transfer fluid. A heat transfer system may include the heat transfer fluid, wherein the heat transfer system may be a vapor compression system including an evaporator, a condenser and a compressor in fluid communication.

[0041] In another form thereof, the present invention provides a method for converting thermal energy to mechanical energy in a Rankine cycle, the method including the steps of: i) vaporizing the heat transfer fluid with a heat source and expanding the resulting vapor; and ii) cooling the heat transfer fluid with a heat sink to condense the vapor. The heat source temperature may be from about 90°C to about 800°C or the heat source temperature may be from about 90°C to about 1000°C

[0042] “Global Warming Potential” (hereinafter“GWP”) was developed to allow comparisons of the global warming impact of different gases. It is a measure of how much energy the emission of one ton of a gas will absorb over a given period of time, relative to the emission of one ton of carbon dioxide. The larger GWP, the more that a given gas warms the Earth compared to CO2 over that time period. The time period usually used for GWP is 100 years. GWP provides a common measure, which allows analysts to add up emission estimates of different gases. See Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report (AR5), 2014. TFMCB has a GWP of 44 as calculated from the atmospheric lifetime and radiative efficiency (Reference for procedure: Hodnebrog, Etminan, Fuglestvedt, Marston, Myhre, Nielsen, Shine, Wallington“Global Warming

Potentials and Radiative Efficiencies of Halocarbons and Related Compounds: A

Comprehensive Review” Reviews of Geophysics, 51 , 2013. DOI: 8755-1209/13/10.1002/rog.20013.

[0043] LC50 is a measure of the acute toxicity of a compound. The acute inhalation toxicity of a compound can be assessed using the method described in the OECD Guideline for Testing of Chemicals No. 403 "Acute Inhalation Toxicity" (2009), Method B.2. (Inhalation) of Commission Regulation (EC) No. 440/2008. TFMCB has an LC50 of > 19.15 mg/L.

[0044] The flash pint of a thermal management fluid refers the lowest temperature at which vapors of the liquid will keep burning after the ignition source is removed as determined in accordance with ASTM D3828. Thermal management fluids which do not have a flash point below 100 °F (37.8 °C) are classified as“non-flammable” in accordance with NFPA 30: Flammable and Combustible Liquid Code.

[0045] “Non-flammable” in the context of a thermal management composition or fluid means compounds or compositions which are determined to be non-flammable. The

flash point of a thermal management composition or fluid refers the lowest temperature at which vapors of the composition will keep burning after the ignition source is removed as determined in accordance with ASTM D3828. Thermal management compositions or fluids which do not have a flash point below 100°F (37.8°C) are classified as“non-flammable” in accordance with NFPA 30: Flammable and Combustible Liquid Code.

[0046] The phrase“no or low toxicity” in the context of a refrigerant composition is classified as class“A” by ASHRAE Standard 34-2016 Designation and Safety Classification of Refrigerants and described in Appendix B1 to ASHRAE Standard 34-2016.

[0047] In the context of a refrigerant composition, a compound or composition which is non-flammable and low or no-toxicity would be classified as“A1” by ASHRAE Standard 34-2016 Designation and Safety Classification of Refrigerants and described in Appendix B1 to ASHRAE Standard 34-2016.

[0048] “Capacity” is the amount of cooling provided, in BTUs/hr, by the refrigerant in the refrigeration system. This is experimentally determined by multiplying the change in enthalpy in BTU/lb, of the refrigerant as it passes through the evaporator by the mass flow rate of the refrigerant. The enthalpy can be determined from the measurement of the pressure and temperature of the refrigerant. The capacity of the refrigeration system relates to the ability to maintain an area to be cooled at a specific temperature. The capacity of a refrigerant represents the amount of cooling or heating that it provides and provides some measure of the capability of a compressor to pump quantities of heat for a given volumetric flow rate of refrigerant. In other words, given a specific compressor, a refrigerant with a higher capacity will deliver more cooling or heating power.

[0049] “Coefficient of Performance” (hereinafter“COP”) is a universally accepted measure of refrigerant performance, especially useful in representing the relative

thermodynamic efficiency of a refrigerant in a specific heating or cooling cycle involving evaporation or condensation of the refrigerant. In refrigeration engineering, this term expresses the ratio of useful refrigeration or cooling capacity to the energy applied by the compressor in compressing the vapor and therefore expresses the capability of a given compressor to pump quantities of heat for a given volumetric flow rate of a heat transfer fluid, such as a refrigerant. In other words, given a specific compressor, a refrigerant with a higher COP will deliver more cooling or heating power. One means for estimating COP of a refrigerant at specific operating conditions is from the thermodynamic properties of the refrigerant using standard refrigeration cycle analysis techniques (see for example, R.C. Downing, FLUOROCARBON REFRIGERANTS HANDBOOK, Chapter 3, Prentice-Hall, 1988 which is incorporated herein by reference in its entirety).

[0050] “Thermal Efficiency” is a measure of how efficiently one can convert energy from a heat source to work. This property is generally used to characterize the performance of an Organic Rankine Cycle System much like COP is used to measure the efficiency of a vapor compression system. One means for estimating COP of a refrigerant at specific operating conditions is from the thermodynamic properties of the refrigerant using standard refrigeration cycle analysis techniques (see for example, Engineering and Chemical Thermodynamics, Milo D. Koretsky. Wiley 2004, page 138.

BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is a schematic representation of a thermal management system of the present invention.

[0052] Figure 2A is a schematic representation of an immersion cooling system according to the present invention.

[0053] Figure 2B is a schematic representation of another immersion cooling system according to the present invention.

[0054] Figure 3 is a chart of the data reported in Example 9.

[0055] Figure 4 is a schematic illustration of a battery thermal management system according to one embodiment of the present invention.

[0056] Figure 5 is a schematic diagram of an exemplary organic Rankine cycle.

[0057] Figure 6 is a schematic diagram of an exemplary heat pump.

[0058] Figure 7 is a schematic diagram of an exemplary secondary loop system.

[0059] Figure 8 is an exemplary immersion cooling system according to Example 10.

DETAILED DESCRIPTION

[0060] The heat transfer fluid may be a refrigerant or a thermal management fluid.

[0061] The compound 1-trifluoromethyl-1 ,2,2-trifluorocyclobutane (“TFMCB”) has the following chemical structure:

1-trifluoromethyl-1 ,2,2-trifluorocyclobutane (“TFMCB”) may also be referred to by alternative names, including 1 ,2,2-trifluoro-1 -trifluoromethyl cyclobutane, 1 ,2,2-trifluoro-1-

trifluoromethylcyclobutane, 1 , 1 ,2-trifluoro-2-trifluoromethyl-cyclobutane, or

hexafluoropropylene/ethylene cyclic dimer.

[0062] TFMCB may be manufactured by any appropriate method. Suitable methods include those set out in US-A-9856193 and US-A-10005705, the entire of which are hereby incorporated by reference.

Heat transfer fluid

[0063] The present invention provides various methods, processes and uses using a heat transfer fluid comprising TFMCB.

[0064] When the heat transfer fluid is used in thermal management (e.g. in electronic cooling), it is referred to as a thermal management fluid. When the heat transfer fluid is used in a heat transfer system (e.g. a vapour compression heat transfer system), it is referred to as a refrigerant. When the heat transfer fluid is used in an Organic Rankine Cycle, it is referred to as a working fluid.

[0065] The heat transfer fluid may comprise TFMCB in an amount of at least about 50% by weight, or at least about 70% by weight, or at least about 90% by weight or at least about 95 % by weight or at least about 99% by weight, excluding non-heat transfer components, or the heat transfer fluid may consist essentially of or consist of TFMCB.

[0066] When the heat transfer fluid is used as a working fluid in an Organic Rankine Cycle, the working fluid preferably comprises at least about 50% by weight of TFMCB, based on the weight of the heat transfer components. Preferably, the working fluid comprises at least about 70% by weight of TFMCB, more preferably at least about 80% by weight of TFMCB, more preferably at least about 90% by weight of TFMCB, based on the weight of the heat transfer components.

[0067] In a particularly preferred feature of the invention, when the heat transfer fluid is used a working fluid in an Organic Rankine Cycle, the working fluid consists essentially of TFMCB. More preferably, when the heat transfer fluid is used a working fluid in an Organic Rankine Cycle, the working fluid consists of TFMCB.

[0068] Alternatively, when the heat transfer fluid is used as a working fluid in an Organic Rankine Cycle the working fluid preferably comprises TFMCB with the proviso that the working fluid is not an azeotrope which is an admixture of about 21 to 27 weight percent TFMCB, 64 to 72 weight percent trans-1 ,2-dichloroethylene and about 5 to 11 weight percent methanol and the working fluid is not an azeotropic composition which is an admixture of about 82 to 92 weight percent TFMCB and about 8 to 18 weight percent methanol or an admixture of about 82 to 92 weight percent TFMCB and about 8 to 18 weight percent ethanol.

[0069] More preferably, when the heat transfer fluid is used a working fluid in an

Organic Rankine Cycle, the working fluid preferably comprises at least about 50% by weight of TFMCB, based on the weight of the heat transfer components, and with the proviso that the working fluid is not an azeotropic composition which is an admixture of about 82 to 92 weight percent TFMCB and about 8 to 18 weight percent methanol or an admixture of about 82 to 92 weight percent TFMCB and about 8 to 18 weight percent ethanol.

[0070] Preferably, the working fluid preferably comprises at least about 70% by weight of TFMCB, based on the weight of the heat transfer components, with the proviso that the working fluid is not an azeotropic composition which is an admixture of about 82 to 92 weight percent TFMCB and about 8 to 18 weight percent methanol or an admixture of about 82 to 92 weight percent TFMCB and about 8 to 18 weight percent ethanol. More preferably the working fluid comprises at least about 80% by weight of TFMCB with the proviso that the working fluid is not an azeotropic composition which is an admixture of about 82 to 92 weight percent TFMCB and about 8 to 18 weight percent methanol or an admixture of about 82 to 92 weight percent TFMCB and about 8 to 18 weight percent ethanol.

[0071] When the heat transfer fluid is used as a refrigerant in a high temperature heat pump, the refrigerant preferably comprises TFMCB, with the proviso that the refrigerant is not an azeotrope which is an admixture of about 21 to 27 weight percent TFMCB, 64 to 72 weight percent trans-1 ,2-dichloroethylene and about 5 to 11 weight percent methanol and the refrigerant is not an azeotropic composition which is an admixture of about 82 to 92 weight percent TFMCB and about 8 to 18 weight percent methanol or an admixture of about 82 to 92 weight percent TFMCB and about 8 to 18 weight percent ethanol.

[0072] Preferably, the refrigerant comprises at least about 50% by weight of TFMCB, preferably at least about 70% by weight of TFMCB, more preferably at least about 80% by weight of TFMCB, more preferably at least about 90% by weight of TFMCB, based on the weight of the refrigerant components, excluding non-refrigerant components such as lubricants.

[0073] In a particularly preferred feature of the invention, when the heat transfer fluid comprises a refrigerant used in a high temperature heat pump, the refrigerant consists essentially of TFMCB. More preferably, when the heat transfer fluid is used a refrigerant in a high temperature heat pump, the refrigerant consists of TFMCB.

[0074] More preferably, when the heat transfer fluid is used as a refrigerant in a high temperature heat pump, the refrigerant preferably comprises at least about 50% by weight of TFMCB, based on the weight of the refrigerant components, and with the proviso that the refrigerant is not an azeotropic composition which is an admixture of about 82 to 92 weight percent TFMCB and about 8 to 18 weight percent methanol or an admixture of about 82 to 92 weight percent TFMCB and about 8 to 18 weight percent ethanol.

[0075] Preferably, the refrigerant preferably comprises at least about 70% by weight of TFMCB, based on the weight of the refrigerant components, with the proviso that the refrigerant is not an azeotropic composition which is an admixture of about 82 to 92 weight percent TFMCB and about 8 to 18 weight percent methanol or an admixture of about 82 to 92 weight percent TFMCB and about 8 to 18 weight percent ethanol. More preferably the refrigerant preferably comprises at least about 80% by weight of TFMCB with the proviso that the refrigerant is not an azeotropic composition which is an admixture of about 82 to 92 weight percent TFMCB and about 8 to 18 weight percent methanol or an admixture of about 82 to 92 weight percent TFMCB and about 8 to 18 weight percent ethanol.

[0076] The heat transfer fluid may comprise one or more co-fluids. For example, the heat transfer fluid may comprise TFMCB, and one or more co-fluids selected from the group consisting of HFE-7000, HFE-7200, HFE-7100, HFE-7300, HFE-7500, HFE-7600, trans-1 ,2-dichloroethylene, n-pentane, cyclopentane, ethanol, perfluoro(2-methyl-3-pentanone) (Novec 1230), cis-HFO-1336mzz, trans-HFO-1336mzz, HF-1234yf, HFO-1234ze(E), HFO-1233zd(E) and HFO-1233zd(Z).

[0077] When the heat transfer fluid is used as a thermal management fluid, the co fluid is preferably HFE-7000, HFE-7200, HFE-7100, HFE-7300, HFE-7500, HFE-7600, trans-1 ,2-dichloroethylene, n-pentane, cyclopentane, methanol, ethanol, perfluoro(2-methyl-3-pentanone) (Novec 1230), cis-HFO-1336mzz, HFO-1233zd(E), HFO-1233zd(Z).

[0078] When the heat transfer fluid is used as a refrigerant, the co-fluid is preferably n-pentane, cyclopentane, cis-HFO-1336mzz, trans-HFO-1336mzz, HFO-1233zd(E), HFO-1233zd(Z) HFO-1234yf, HFO-1234ze(E).

[0079] When the heat transfer fluid comprises TFMCB and a co-fluid, the heat transfer fluid may comprise TFMCB in an amount of at least about 5% by weight, or at least about 15% by weight, or at least about 50% by weight, or at least about 70% by weight, or at least about 90% by weight, or at least 95 % by weight or at least 99% by weight. The one or more co-fluids may be present in an amount of at least about 5% by weight, or at least about 10% by weight of the heat transfer fluid.

[0080] The heat transfer fluid may consist essentially of TFMCB and the one or more co-fluids. The heat transfer fluid may consist of TFMCB and the one or more co-fluids.

[0081] It will be appreciated that the heat transfer fluid may consist essentially of

TFMCB. It will also be appreciated that the heat transfer fluid may consist of TFMCB.

[0082] It has surprisingly been discovered that TFMCB is non-flammable (and has no flash point) and has a GWP of about 44. This is particularly surprising, because GWP and flammability are generally inversely correlated.

[0083] The present invention thus includes heat transfer fluids that are preferably non-flammable.

[0084] When the heat transfer fluid is a refrigerant, it will be appreciated that the refrigerant is preferably a Class 1 refrigerant.

[0085] When the heat transfer fluid is a thermal management fluid, it will be appreciated that the thermal management fluid preferably has no flash point, or a flash point of above about 100 oF (37.8oC).

[0086] It has also been surprisingly discovered that TFMCB displays low levels of toxicity.

[0087] Therefore, the heat transfer fluid is preferably a low or no toxicity heat transfer fluid.

[0088] When the heat transfer fluid is a refrigerant, it will be appreciated that the refrigerant is preferably a class A refrigerant.

[0089] It is also preferred that the heat transfer fluid is non-flammable and is a low or no-toxicity heat transfer fluid.

[0090] When the heat transfer fluid is a refrigerant, it will be appreciated that the refrigerant is preferably a class A1 refrigerant and is a low or no-toxicity refrigerant.

[0091] Preferably, the heat transfer fluid (and therefore also the thermal

management fluid, working fluid or refrigerant) has a low GWP. For example, the heat transfer fluid may have a GWP of not greater than about 1000, or not greater than about 700, or not greater than about 500, or not greater than about 300, or not greater than about 150. Preferably, the heat transfer fluid (and therefore also the thermal management fluid or refrigerant) has a GWP of not greater than about 150.

[0092] It will be appreciated that the heat transfer fluid (and therefore also the thermal management fluid, working fluid or refrigerant) may have a combination of one or more of the above properties.

Heat transfer composition

[0093] The present invention also provides a heat transfer composition comprising a heat transfer fluid of the invention.

[0094] The heat transfer composition may comprise at least about 50% by weight, or at least about 70% by weight, or at least about 90% by weight of the heat transfer fluid. [0095] The heat transfer composition may include other components for the purpose of enhancing or providing certain functionality to the composition.

[0096] Preferably, the heat transfer composition comprises a lubricant. The lubricant lubricates the refrigeration compressor using the refrigerant. The lubricant may be present in the heat transfer composition in amounts of from about 5% to about 30% by weight of heat transfer composition. Lubricants such as Polyol Esters (POEs), Poly Alkylene Glycols (PAGs), PAG oils, polyvinyl ethers (PVEs), and poly(alpha-olefin) (PAO) and combinations thereof may be used in the heat transfer compositions of the present invention.

[0097] Preferred lubricants include POEs and PVEs, more preferably POEs. Of course, different mixtures of different types of lubricants may be used. For example, the lubricant may be a PAG if the refrigerant is used in mobile air conditioning applications.

[0098] The heat transfer composition therefore comprises a refrigerant of the invention and a lubricant selected from a POE, a PAG or a PVE.

[0099] The heat transfer composition of the present invention may consist essentially of or consist of a heat transfer fluid and lubricant as described above.

[00100] Commercially available mineral oils include Witco LP 250 (registered trademark) from Witco, Zerol 300 (registered trademark) from Shrieve Chemical, Sunisco 3GS from Witco, and Calumet R015 from Calumet. Commercially available alkyl benzene lubricants include Zerol 150 (registered trademark). Commercially available esters include neopentyl glycol dipelargonate, which is available as Emery 2917 (registered trademark) and Hatcol 2370 (registered trademark). Other useful esters include phosphate esters, dibasic acid esters, and fluoroesters.

[00101] The heat transfer composition may include a compatibilizer for the purpose of aiding compatibility and/or solubility of the lubricant. Suitable compatibilizers may include propane, butanes, pentanes, and/or hexanes. When present, the compatibilizer is preferably present in an amount of from about 0.5% to about 5% by weight of the heat transfer composition. Combinations of surfactants and solubilizing agents may also be added to the present compositions to aid oil solubility, as disclosed by U.S. Patent No. 6,516,837, the disclosure of which is incorporated by reference.

Uses, Methods and systems

[00102] The present invention includes method for transferring heat as described herein, included methods as specifically described above and hereinafter.

[00103] The present invention also includes devices and systems for transferring heat as described herein, included devices and systems as specifically described above and hereinafter.

[00104] The heat transfer fluid, thermal management fluid, refrigerant, working fluid and heat transfer compositions of the invention are provided for use for heating and/or cooling as set out below.

[00105] Thus, the present invention describes a method of heating or cooling a fluid or body using a heat transfer fluid, thermal management fluid, refrigerant, working fluid or heat transfer compositions of the invention.

Thermal management Methods, Devices, Systems and Uses.

[00106] In nearly every modern application of electronics, the dissipation of heat is an important consideration. For example, in portable and hand-held devices, the desire to miniaturize while adding functionality increases the thermal power density, which increases the challenge of cooling the electronics within them. As computational power increases within desktop computers, datacenters and telecommunications centers, so does the heat output. Power electronic devices such as the traction inverters in plug-in electric or hybrid vehicles, wind turbines, train engines, generators and various industrial processes make use of transistors that operate at ever higher currents and heat fluxes.

[00107] As discussed above, when the heat transfer fluid as described above is used in a method or device or system of cooling and/or heating in an electronic device, it is sometimes referred to herein as a thermal management fluid. The thermal management fluid therefore corresponds to the heat transfer fluid as discussed in this application. All preferred features of the heat transfer fluid as described apply to the thermal insulation fluid as described herein.

[00108] Preferred embodiments of the present thermal management methods will now be described in connection with Figure 1 in which an operating electronic device is shown schematically as 10 having a source electrical energy and/or signals 20 flowing into and/or out of the device 10 and which generates heat as a result of its operation based on the electrical energy and/or signals 20. The thermal management fluid of the present invention is provided in thermal contact with the operating device 20 such that it removes heat, represented by the out flowing arrow 30. Heat is removed from the operating electronic device by sensible heat being added to the liquid thermal management fluid of the present invention (i.e., increasing the temperature of the liquid), or by causing a phase change in the thermal management liquid (i.e., vaporizing the liquid) or a combination of these. In preferred embodiments, the methods provide a supply of heat transfer fluid to the device 10 such that the flow of heat from the device 10 through the present heat transfer fluid 30 maintains the operating electrical device at or within a preferred operating temperature range. In preferred embodiments, the preferred operating temperature range of the electrical device is from about 70C to about 150C, and even more preferably from about 70C to about 120C, and the flow of heat 30 from the device 10 through the present heat transfer fluid energy maintains the operating electrical device at or within such preferred temperature ranges. Preferably, the heat transfer fluid 30 of the present invention, which has absorbed the heat from the device, is in thermal contact with a heat sink, represented schematically as 40, at a temperature below the temperature of the heat transfer fluid 30 and thereby transfers the heat generated by the device 10 to the heat sink 40. In this way, the heat-depleted heat transfer fluid of the present invention 50 can be returned to the electronic device 10 to repeat the cycle of cooling.

[00109] In a preferred embodiment of the present methods, the step of removing heat through the present heat transfer composition comprises evaporating the heat transfer fluid of the present invention using the heat generated by the operation of the electronic device, and the step of transferring that heat from the heat transfer composition to the heat sink comprises condensing the heat transfer fluid by rejecting heat to the heat sink. In such methods, the temperature of the heat transfer fluid during said evaporation step is greater than 50°C, or preferably greater than about 55°C, or preferably in the range of from about 55°C to about 85°C, or preferably from about 65°C to about 75°C. Applicants have found that the present heat transfer fluids provide excellent performance in such methods and at the same time allow the use for relatively low cost, lightweight and reliable equipment to provide the necessary cooling, as will be explained further in connection with particular embodiments as described in connection with Figure 2A below.

[00110] In a further preferred embodiment of the present methods, the step of removing heat through the present heat transfer composition comprises adding sensible heat to the liquid heat transfer composition of the present invention (e.g., raising the temperature of the liquid up to about 70°C or less at about atmospheric pressure, i.e., wherein the fluid is not required to be in a high pressure container or vessel) using the heat generated by the operation of the electronic device, and the step of transferring that heat from the heat transfer composition to a heat sink and thereby reducing the liquid temperature by rejecting heat to the heat sink. The cooled liquid is then returned to thermal contact with the electrical device wherein the cycle starts over. In preferred embodiments, the temperature of the heat transfer liquid that has its heat transferred to the heat sink is greater than 50°C, or preferably greater than about 55°C, or preferably in the range of from about 45°C to about 70°C, or preferably from about 45°C to about 65°C, and preferably is at a pressure that is about atmospheric. Applicants have found that the present heat transfer liquids provide excellent performance in such methods and at the same time allow the use for relatively low cost, lightweight and reliable equipment to provide the necessary cooling, as will be explained further in connection with particular embodiments as described in connection with Figure 2B below.

[00111] It will be appreciated by those skilled in the art that the present invention comprises systems and methods which use both sensible heat transfer and phase change heat transfer as describe above.

[00112] A particular method according to the present invention will now be described in connection with Figures 2A and 2B in which an electronic device 10 is contained in an appropriate container 12, and preferably a sealed container, and is in direct contact with, and preferably fully immersed in liquid heat transfer composition of the present invention 11 A (shown schematically by gray shading). The operating electronic device 10 has a source of electrical energy and/or signals 20 flowing into and/or out of the container 12 and into and/or out of device 10, which generates heat as a result of its operation based on the electrical energy and/or signals 20. As those skilled in the art will appreciated, it is a significant challenge to discover a heat transfer fluid that can perform effectively in such applications since the fluid must not only provide all of the other properties mentioned above, it must be able to do so while in intimate contact with an operating electronic device, that is, one which involves the flow of electrical current/signals. It will be appreciated that many fluids that might be otherwise viable for use in such applications will not be useable because they will either short-out the device, degrade when exposed to the conditions created by the operation of the electronic device or have some other property detrimental to operation when in contact with an operating electronic device.

[00113] In contrast, the present methods produce excellent results by providing the thermal management fluid of the present invention in direct thermal and physical contact with the device 10 as it is operating. This heat of operation is safely and effectively transferred to the thermal management fluid 11 A by: (a) causing the liquid phase of the fluid to evaporate and form vapor 11 B; or (b) raising the temperature of the liquid thermal management fluid 11 A; or (c) a combination of (a) and (b).

[00114] In the case of the phase change heat transfer systems of the present invention, reference is made herein to Figure 2A. In such an operation, heat is carried away from the device 10 as the liquid evaporates and the vapor rises through the remaining thermal management liquid in the container 12. The thermal management fluid vapor 11 B then rejects the heat it has absorbed to a heat sink 40, which can be an enclosed heat sink 40A and/or an external heat sink 40B. An example of a heat sink that is internal to the container 12 are condenser coils 30A and 30B with circulating liquid, such as water, at a temperature below the condensing temperature of the thermal management fluid vapor. An example of a heat sink that is external to the container 12 would be passing relatively cool ambient air over the container 12 (which preferably in such case include cooling fins or the like), which will serve to condense the heat transfer vapor 11 B on the interior surface of the container. As a result of this condensation, liquid thermal management fluid is returned to the pool of liquid fluid 11A in which the device 10 remains immersed in operation.

[00115] In the case of a sensible heat transfer systems of the present invention, reference is made herein to Figure 2B. In such an operation heat is carried away from the device as the temperature of liquid increases upon accepting heat being generated by the device, which is immersed, and preferably substantially fully immersed in the thermal management fluid 11 A of the present invention. The higher temperature thermal management fluid liquid 11 A then rejects the heat it has absorbed to a heat sink 40, which can be an enclosed heat sink 40A and/or an external heat sink 40B. An example of a heat sink that is internal to the container 12 are cooling coils 30A and 30B with circulating liquid, such as water, at a temperature below the temperature of heated liquid. An example of a heat sink that is external to the container 12 would be removing heated liquid 11 A from the container through a conduit 45 where it is thermally contacted with a cool fluid, such as might be provided by relatively cool ambient air or a refrigerant, which will serve to lower the temperature of the liquid. Cooled liquid is then returned via conduit 46.

[00116] Optionally, but preferably in certain embodiments involving thermal management of the batteries used in electronic vehicles, the thermal management system includes a heating element which is able to heat the thermal management fluid, such as for example an electrical heating element 60 which is also immersed in the thermal

management fluid. As those skilled in the art will appreciate, the batteries in electronic vehicles (which would correspond to the operating electronic device 10 in Figures 2A and 2B) can reach relatively low temperatures while parked outside in the winter months in many geographical locations, and frequently such low temperature conditions are not desirable for battery operation. Accordingly, the thermal management system of the present invention can include sensors and control modules (not shown) which turn on the heating element when the battery temperature is below a predetermined level. In such a case, the heater 60 would be activated, the thermal management liquid 11A would be heated, and would in turn transfer this heat to the electronic device 10 until the minimum temperature is reached. Thereafter during operation, the thermal management fluid of the present invention would serve the cooling function as described above.

[00117] For the purposes of this invention, the thermal management fluid can be in direct contact with the heat-generating component or in indirect contact with the heat generating component.

[00118] When the thermal management fluid is in indirect contact with the heat generating component, the thermal management fluid can be used in a closed system in the electronic device, which may include at least two heat exchangers. When the thermal

management fluid is used to cool the heat-generating component, heat can be transferred from the component to the thermal management fluid, usually through a heat exchanger in contact with at least a part of the component or the heat can be transferred to circulating air which can conduct the heat to a heat exchanger that is in thermal contact with the thermal management fluid.

[00119] In a particularly preferred feature of the present invention, the thermal management fluid is in direct contact with the heat-generating component. In particular, the heat generating component is fully or partially immersed in the thermal management fluid. Preferably the heat generating component is fully immersed in the thermal management fluid. The thermal management fluid, as a warmed fluid or as a vapor, can then be circulated to a heat exchanger which takes the heat from the fluid or vapor and transfers it to the outside environment. After this heat transfer, the cooled thermal management fluid (cooled or condensed) is recycled back into the system to cool the heat-generating component.

[00120] When the thermal management fluid is a single-phase liquid, it will remain liquid when heated by the heat-generating component. Thus, the thermal management fluid can be brought into contact with the heat generating component, resulting in the removal of the heat from the heat generating component and the production of a thermal management fluid with a higher temperature. The thermal management fluid is then transported to a secondary cooling loop, such as a radiator or another refrigerated system. An example of such a system is illustrated in Figure 2, where the thermal management fluid enters a battery pack enclosure containing a number of cells and exits the enclosure having taken up heat from the battery pack.

[00121] When the thermal management fluid has two phases, the heat-generating component is in thermal contact with the thermal management fluid and transfers heat to the thermal management fluid, resulting in the boiling of the thermal management fluid. The thermal management fluid is then condensed. An example of such a system is where the heat-generating component is immersed in the thermal management fluid and an external cooling circuit condenses the boiling fluid into a liquid state.

[00122] Electrical conductivity of a thermal management fluid becomes important if the fluid comes in direct contact with the electronic components of the electronic device (such as in direct immersion cooling), or if the thermal management fluid leaks out of a cooling loop or is spilled during maintenance and comes in contact with the electrical circuits. Thus, the thermal management fluid is preferably an electrically insulating thermal management fluid.

[00123] The thermal management fluid may be recirculated passively or actively in the device, for example by using mechanical equipment such as a pump. In a preferred feature of the present invention, the thermal management fluid is recirculated passively in the device.

[00124] Passive recirculating systems work by transferring heat from the heat generating component to the thermal management fluid until it typically is vaporized, allowing the heated vapor to proceed to a heat exchange surface at which it transfers its heat to the heat exchanger surface and condenses back into a liquid. It will be appreciated that the heat exchange surface can be part of a separate heat exchange unit and/or can be integral with the container, as described above for example in connection with Figure 2. The condensed liquid then returns, preferably fully passively by the force of gravity, into the thermal management fluid in contact with the heat-generating component. Thus, in a preferred feature of the invention, the step of transferring heat from the heat-generating component to the thermal management fluid causes the thermal management fluid to vaporize.

[00125] Examples of passive recirculating systems include a heat pipe or a thermosyphon. Such systems passively recirculate the thermal management fluid using gravity. In such a system, the thermal management fluid is heated by the heat-generating component, resulting in a heated thermal management fluid which is less dense and more buoyant. This thermal management fluid travels to a storage container, such as a tank where it cools and condenses. The cooled thermal management fluid then flows back to the heat source.

[00126] The electronic device includes a heat-generating component. The heat generating component can be any component that includes an electronic element that as part of its operation generates heat. For the purposes of this invention, the heat generating component can be selected from semiconductor integrated circuits (ICs), electrochemical cells, power transistors, resistors, and electroluminescent elements, such as

microprocessors, wafers used to manufacture semiconductor devices, power control semiconductors, electrical distribution switch gear, power transformers, circuit boards, multi chip modules, packaged or unpackaged semiconductor devices, semiconductor integrated circuits, fuel cells, lasers (conventional or laser diodes), light emitting diodes (LEDs), and electrochemical cells, e.g. used for high power applications such as, for example, hybrid or electric vehicles.

[00127] For the purpose of this invention, the electronic device can be selected from personal computers, microprocessors, servers, cell phones, tablets, digital home appliances (e.g. televisions, media players, games consoles etc.), personal digital assistants,

Datacenters, batteries both stationary and in vehicles, hybrid or electric vehicles, wind turbine, train engine, or generator. Preferably the electronic device is a hybrid or electric vehicle.

[00128] The present invention further relates to an electronic device comprising a thermal management fluid of the invention. For the purposes of this invention, the thermal management fluid is provided for cooling and/or heating the electronic device.

[00129] The present invention further relates to an electronic device comprising a heat generating component and a thermal management fluid of the invention. For the purposes of this invention, the electronic device can further comprise a heat exchanger, particularly where the heat exchanger is in contact with at least a part of the heat generating component.

[00130] The present invention further relates to an electronic device comprising a heat generating component, a heat exchanger, a pump and a thermal management fluid of the invention.

[00131] For the purposes of this invention, the heat generating component can be selected from semiconductor integrated circuits (ICs), electrochemical cells, power transistors, resistors, and electroluminescent elements, such as microprocessors, wafers used to manufacture semiconductor devices, power control semiconductors, electrical distribution switch gear, power transformers, circuit boards, multi-chip modules, packaged or unpackaged semiconductor devices, semiconductor integrated circuits, fuel cells, lasers (conventional or laser diodes), light emitting diodes (LEDs), and electrochemical cells, e.g. used for high power applications such as, for example, hybrid or electric vehicles.

[00132] For the purpose of this invention, the electronic device can be selected from personal computers, microprocessors, servers, cell phones, tablets, digital home appliances (e.g. televisions, media players, games consoles etc.), personal digital assistants,

Datacenters, hybrid or electric vehicles, batteries both stationary and in vehicles, wind turbine, train engine, or generator, preferably wherein the electronic device is a hybrid or electric vehicle.

[00133] The invention further relates to the use of a thermal management fluid of the invention for cooling an electronic device. For the purpose of this invention, the electronic device can be selected from personal computers, microprocessors, servers, cell phones, tablets, digital home appliances (e.g. televisions, media players, games consoles etc.), personal digital assistants, Datacenters, hybrid or electric vehicles, batteries both stationary and in vehicles, wind turbine, train engine, or generator, preferably wherein the electronic device is a hybrid or electric vehicle.

Uses of refrigerant and heat transfer composition

[00134] The invention also provides a heat transfer system comprising a refrigerant or a heat transfer composition of the invention. It will be appreciated that the heat transfer systems described herein may be vapor compression systems having an evaporator, a condenser and a compressor in fluid communication.

[00135] The refrigerant or heat transfer composition of the invention may be used as a secondary fluid.

[00136] It will be appreciated that the refrigerant or heat transfer composition of the invention may be used in a variety of different heat transfer applications.

Organic Rankine Cycle

[00137] As discussed above, when the heat transfer fluid as described above is used in an Organic Rankine cycle, it is referred to as a working fluid. The working fluid therefore corresponds to the heat transfer fluid as discussed in this application. All preferred features of the heat transfer fluid apply to the working fluid as described herein.

[00138] Rankine cycle systems are known to be a simple and reliable means to convert heat energy into mechanical shaft power. In industrial settings, it may be possible to use flammable working fluids such as toluene and pentane, particularly when the industrial setting has large quantities of flammables already on site in processes or storage. However, for instances where the risk associated with use of a flammable and/or toxic working fluid is not acceptable, such as power generation in populous areas or near buildings, it is necessary to use non-flammable and/or non-toxic refrigerants as the working fluid. There is also a drive in the industry for these materials to be environmentally acceptable in terms of GWP.

[00139] The process for recovering waste heat in an Organic Rankine cycle involves pumping liquid-phase working fluid through a boiler where an external (waste) heat source, such as a process stream, heats the working fluid causing it to evaporate into a saturated or superheated vapor. This vapor is expanded through a turbine wherein the waste heat energy is converted into mechanical energy. Subsequently, the vapor phase working fluid is condensed to a liquid and pumped back to the boiler in order to repeat the heat extraction cycle.

[00140] Referring to Figure 6, in an exemplary organic Rankine cycle system 70, working fluid is circulated between an evaporator device 71 and a condenser 75, with a pump device 72 and an expansion device 74 functionally disposed therebetween. In the illustrated embodiment, an external flow of fluid is directed to evaporator 71 via external warm conduit 76. External warm conduit 76 may carry fluid from a warm heat source, such

as a waste heat source from industrial processes (e.g., power generation), flue gases, exhaust gases, geothermal sources, etc.

[00141] Evaporator 71 is configured as a heat exchanger which may include, e.g., a series of thermally connected, but fluidly isolated, tubes carrying fluid from warm conduit 76 and fluid from working fluid conduit 77B respectively. Thus, evaporator 71 facilitates the transfer of heat QIN from the warm fluid arriving from external warm conduit 76 to the relatively cooler (e.g.,“cold”) working fluid arriving from expansion device 74 via working fluid conduit 77B.

[00142] The working fluid issued from evaporator 71 , having thus been warmed by the absorption of heat QIN, then travels through working fluid conduit 78A to pump 72. Pump 72 pressurizes the working fluid, thereby further warming the fluid through external energy inputs (e.g., electricity). The resulting“hot” fluid passes to an input of condenser 75 via conduit 78B, optionally via a regenerator 73 as described below.

[00143] Condenser 75 is configured as a heat exchanger similar to evaporator 71 , and may include, e.g., a series of thermally connected, but fluidly isolated, tubes carrying fluid from cool conduit 79 and fluid from working fluid conduit 78B respectively. Condenser 75 facilitates the transfer of heat QOUT to the cool fluid arriving from external cool conduit 79 to the relatively warmer (e.g.,“hot”) working fluid arriving from pump 72 via working fluid conduit 78B.

[00144] The working fluid issued from condenser 75, having thus been cooled by the loss of heat QOUT, then travels through working fluid conduit 77A to expansion device 74. Expansion device 74 allows the working fluid to expand, thereby further cooling the fluid. At this stage, the fluid may perform work, e.g., by driving a turbine. The resulting“cold” fluid passes to an input of evaporator 71 via conduit 77B, optionally via a regenerator 73 as described below, and the cycle begins anew.

[00145] Thus, working fluid conduits 77A, 77B, 78A and 78B define a closed loop such that the working fluid contained therein may be reused indefinitely, or until routing maintenance is required.

[00146] In the illustrated embodiment, regenerator 73 may be functionally disposed between evaporator 71 and condenser 75. Regenerator 73 allows the“hot” working fluid issued from pump 72 and the“cold” working fluid issued from expansion device 74 to exchange some heat, potentially with a time lag between deposit of heat from the hot working fluid and release of that heat to the cold working fluid. In some applications, this can increase the overall thermal efficiency of Rankine cycle system 70

[00147] Therefore, the invention relates to an organic Rankine cycle comprising a working fluid of the present invention.

[00148] The invention further relates to the use of a working fluid of the invention in an Organic Rankine Cycle.

[00149] The invention also provides a process for converting thermal energy to mechanical energy in a Rankine cycle, the method comprising the steps of i) vaporizing a working fluid of the invention with a heat source and expanding the resulting vapor, then ii) cooling the working fluid with a heat sink to condense the vapor, wherein the working fluid is a refrigerant or heat transfer composition of the invention.

[00150] The mechanical work may be transmitted to an electrical device such as a generator to produce electrical power.

CLAIMS:

1. A method for cooling a heat generating component that is operating in an electronic device, said method comprising:

(a) operating said electronic device;

(b) providing a thermal management fluid comprising 1-trifluoromethyl-1 ,2,2- trifluorocyclobutane (TFMCB) in thermal contact with the heat generating component of said operating electronic device; and

(c) transferring heat from said operating, heat-generating component to said thermal management fluid by thermal contact with said TFMCB.

2. The method of claim 1 , wherein the thermal management fluid is in direct contact with the heat generating component and wherein said step of transferring heat comprises vaporizing said TFMCB or adding sensible heat to said TFMCB, or a combination of these.

3. The method of claim 1 or claim 2, wherein the thermal management fluid consists essentially of TFMCB.

4. The method of any of claims 1 -3, wherein the thermal management fluid comprises at least about 50% by weight of TFMCB.

5. The method of any of claims 1 -4, wherein said TFMCB is at a temperature greater than about 55°C during said transferring step (c).

6. The method of any of claims 1 -5, wherein the thermal management fluid has a

dielectric constant of less than 30 and an electrical conductivity of less than 15 nS/cm.

7. The method of any of claims 1 -6, wherein the heat generating component is selected from semiconductor integrated circuits (ICs), electrochemical cells, power transistors, resistors, and electroluminescent elements, such as microprocessors, wafers used to manufacture semiconductor devices, power control semiconductors, electrical distribution switch gear, power transformers, circuit boards, multi-chip modules, packaged or unpackaged semiconductor devices, semiconductor integrated circuits, fuel cells, lasers (conventional or laser diodes), light emitting diodes (LEDs), and electrochemical cells, e.g. used for high power applications such as, for example, hybrid or electric vehicles.

8. The method of any of claims 1-7, wherein said electronic device is selected from

personal computers, microprocessors, servers, cell phones, tablets, digital home appliances (e.g. televisions, media players, games consoles etc.), personal digital assistants, Datacenters, batteries both stationary and in vehicles, hybrid or electric vehicles, wind turbine, train engine, or generator.

9. The method of claim 8, wherein the electronic device is a hybrid or electric vehicle.

10. A process for converting thermal energy to mechanical energy in a Rankine cycle, the method comprising the steps of i) vaporizing a working fluid with a heat source and expanding the resulting vapor, then ii) cooling the working fluid with a heat sink to condense the vapor, wherein the working fluid comprises at least about 50% by weight of TFMCB.

11. A high temperature heat pump comprising a heat transfer fluid, wherein the heat transfer fluid comprises TFMCB, with the proviso that the heat transfer fluid is not an azeotrope which is an admixture of about 21 to 27 weight percent TFMCB, 64 to 72 weight percent trans-1 ,2-dichloroethylene and about 5 to 11 weight percent methanol and the heat transfer fluid is not an azeotropic composition which is an admixture of about 82 to 92 weight percent TFMCB and about 8 to 18 weight percent methanol or an admixture of about 82 to 92 weight percent TFMCB and about 8 to 18 weight percent ethanol.

12. A secondary loop system comprising a refrigerant comprising TFMCB.

13. A heat transfer composition comprising a heat transfer fluid and a lubricant, wherein the heat transfer fluid comprises TFMCB.

14. The heat transfer fluid of claim 13, wherein the lubricant comprises at least one

polyol ester (POE), polyvinyl ether (PVE), and polyalkylene gloycol (PAG).

15. A method of replacing an existing refrigerant in a heat transfer system, said method comprising the steps of:

(a) removing at least a portion of said existing refrigerant from said system and subsequently;

(b) introducing into said system a refrigerant comprising TFMCB.

16. A method for removing heat from an article, device or fluid comprising:

(a) providing a high temperature heat source which is generating heat at a temperature above about 70°C; and

(b) removing heat from said high temperature heat source by thermal contact with TFMCB liquid, wherein the temperature of said TFMCB liquid is above about 55°C.

17. The method of claim 16, wherein said heat transfer fluid comprises at least about 50% by weight of TFMCB.

18. The method of claim 16 or claim 17, wherein said heat transfer fluid comprises at least about 50% by weight of TFMCB.

19. The method of any of claims 16-18 wherein said heat transfer fluid is a non

flammable heat transfer fluid consisting essentially of TFMCB and having a dielectric constant of less than 30 and an electrical conductivity of less than 15 nS/cm.

20. The method of any of claims 16-18 wherein said step of removing heat comprises vaporizing said TFMCB or adding sensible heat to said TFMCB, or a combination of these.