Heat exchange method using fluorinated vinyl ethers with low GWP

Abstract

The present invention provides a method for exchanging heat with a body comprising using a heat transfer fluid, said heat transfer fluid having the following general formula: R f -O-CF2-O-CX=CYZ(I) (where R f may be any C2-C6 linear or branched, or C5C6 cyclic saturated carbon chain, which may be partially or fully fluorinated, and may contain 0 to 5 carbon atoms, all of which, if present, are involved in ether linkages; and X, Y, and Z may be independently selected from halogen or hydrogen, provided that at least one of X, Y, or Z is halogen.

Description

[Technical Field]

[0001] This application claims priority to European Patent Application Publication No. 20193274.6, filed August 28, 2020, the entire contents of which are incorporated herein by reference for all purposes.

[0002] The present invention relates to a method for exchanging heat with a body using a composition comprising selected fluorinated compounds having low GWP as a heat transfer fluid. [Background technology]

[0003] Heat transfer fluids are known in the art for use in heating and cooling systems. Typically, heat transfer fluids include water, saline solutions, alcohols, glycols, ammonia, hydrocarbons, ethers, and various halogenated derivatives of these materials, such as chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HFCs), and (per)fluorinated polyethers (PFPEs).

[0004] Heat transfer fluids are used to transfer heat from one object to another, typically a heat source to a heat sink, resulting in cooling of the heat source, heating of the heat sink, or removal of unwanted heat generated by the heat source. The heat transfer fluid provides a thermal path between the heat source and the heat sink, and it may be circulated by a loop or other flow system to improve heat flow, or it may be in direct contact with the heat source and heat sink. Simpler systems simply use airflow as the heat transfer fluid, while more complex systems use specially designed gases or liquids that are heated or cooled in one portion of the system and then delivered in thermal contact with the target.

[0005] A preferred use of the heat transfer fluids of the present invention is to transfer heat to and from electrical or electronic equipment, particularly to remove excess heat generated during the operation of electrical or electronic equipment. This application is of great industrial importance because electrical and electronic equipment typically perform optimally over a relatively narrow temperature range. These applications include thermostatic chambers and refrigeration circuits, as described in more detail below. In particular, the fluids of the present invention are dielectric fluids, which means they are electrical insulators and can transfer heat to and from electrical and electronic equipment while in direct contact with the electronic equipment, such as wiring or integrated circuits. Furthermore, the use of dielectric fluids is particularly advantageous when these fluids are used in refrigeration circuits, which circulate in sealed pipes (as described in more detail below) and are therefore not intended to come into direct contact with conductive components of the equipment, because the risk of damage to the electrical or electronic equipment is reduced in the event of a leak.

[0006] Computing equipment, such as computers and servers, generates a significant amount of heat. Large-scale developments that centralize many computers operating in a shared location, such as server farms, are becoming increasingly common. The industry for server farms, Bitcoin mining farms, and other supercomputing applications is growing extremely rapidly. A key factor in determining the construction strategy for such facilities is the control system that allows heat to be exchanged with such computing equipment. This system, often referred to as a "thermal management system," is typically used to cool computing equipment during operation, but can also be used for heating, such as when starting up a system in a cold environment. While air remains the most commonly used fluid, it has the disadvantage of requiring large air gaps between electronic boards, resulting in a very large footprint. Air cooling also requires large air conditioning engines, whose energy consumption is significant and accounts for a significant portion of the running costs of such facilities.

[0007] Recently, solutions for server thermal management based on the use of heat transfer fluids, especially liquid heat transfer fluids, have attracted great interest because they are energy efficient (using less energy than traditional air conditioning systems) and allow more servers, processors, and circuit boards to be accommodated in a smaller space.

[0008] Other important specialized applications of heat transfer fluids can be found, for example, in the semiconductor industry (TCU, thermostatic ovens, vapor phase soldering) and in the battery industry, especially in the vehicle battery industry for thermal management systems.

[0009] There are a variety of heat transfer fluids used industrially in a variety of applications; however, the selection of the appropriate fluid can be important in some applications. Some heat transfer fluids commonly used in the past are no longer practical due to their toxicity (ammonia, ethylene glycol), while others have been phased out due to their environmental profile, being non-biodegradable and / or believed to be harmful to the Earth's ozone layer and / or to act as greenhouse gases when dispersed in the environment.

[0010] Fluorinated liquids are very effective heat transfer fluids. Commercially available products include Solvay's Galden and 3M's Fluorinert. These are dielectric, high heat capacity, low viscosity, non-toxic, and chemically inert liquid polymers, allowing them to come into direct contact with electronic substrates and not chemically interact with most materials. A drawback associated with these fluorinated fluids used to date is their high GWP values.

[0011] GWP (Global Warming Potential) is a property that can be determined for a given compound (considering "1" as a baseline value for CO2) that indicates how much heat a given greenhouse gas can trap in the atmosphere, calculated over a specific time interval, typically 100 years (GWP 100 ).

[0012] GWP100 The determination of GWP is done by combining experimental data on the atmospheric lifetime of the compound with its radiative efficiency using special computational tools, which is standard in the art and is described for example in the comprehensive review published by Hodnebrog et al. in Review of Gephysics, 51 / 2013, p300-378. Very stable halogenated molecules such as CF4 and chloro / fluoroalkanes have very high GWPs. 100 (7350 for CF4 and 4500 for CFC-11).

[0013] Over the years, heat transfer fluids with high GWP values ​​(such as chloro / fluoroalkanes used in air conditioning systems) have been phased out in industry, and lower GWP 100 Replaced by compounds with the lowest possible GWP 100 There continues to be a continuing interest in heat transfer fluids that have value.

[0014] Hydrofluoroethers, especially segregated hydrofluoroethers, have a relatively low GWP 100 On the other hand, other of their properties can be compared to the properties of CFCs used in the past, and for this reason some hydrofluoroethers are popularly used industrially as heat transfer fluids, for example marketed by 3M under the trade name "Novec®".

[0015] Hydrofluoroethers are generally described as heat transfer media because of their wide temperature range over which they are liquid, and because of their low viscosity over a wide temperature range that makes them useful for application as low-temperature secondary refrigerants for use in secondary loop refrigeration systems where the viscosity should not be too high at operating temperatures.

[0016] Fluorinated ethers are described, for example, by 3M in U.S. Pat. No. 5,713,211, by Dupont in U.S. Patent Application Publication No. 2007 / 0187639, and by Solvay Solexis in WO 2007 / 099055 and WO 2010034698.

[0017] However, as shown in U.S. Pat. No. 5,713,211 (Table 5), the GWP of segregated hydrofluoroethers 100 is much lower than CFCs, but still in the range of 70-500.

[0018] [Table 1]

[0019] Other hydrofluoroolefins are commercialized as heat transfer fluids, for example by Chemours (Opteon™) and Honeywell (Solstice™). These compounds have a very low GWP of about 1, but unlike the compounds cited above, they are much more twistable, which therefore limits their field of use.

[0020] EP 2020 / 057121, an international PCT patent application by Solvay Specialty Polymers Italy SpA, describes the general use of halogenated vinyl ethers as heat transfer fluids with low GWP, low flammability, and good dielectric properties and heat capacity. However, there is a need for a heat transfer fluid with a better balance of good thermal and dielectric properties, which is liquid over a wide temperature range, non-flammable, and has a very low GWP. 100 There is a continuing need to provide more effective methods for efficient heat transfer using heat transfer fluids having a viscosity of 30 or less. Summary of the Invention

[0021] The present invention provides a method for exchanging heat with a body comprising using a heat transfer fluid, said heat transfer fluid having the general formula: R f -O-CF2-O-CX=CYZ (I) (In the formula, -R f may be any C2-C6 linear or branched or C5C6 cyclic saturated carbon chain, which may be partially or fully fluorinated, and may contain 0 to 5 carbon atoms, all of which, if present, are involved in ether linkages; - X, Y, and Z may be independently selected from halogen or hydrogen, provided that at least one of X, Y, or Z is halogen. The present invention relates to a method comprising the step of: DETAILED DESCRIPTION OF THE INVENTION

[0022] By "electronic computing equipment" is meant any individual or array of individual computer boards, including microprocessor CPUs, GPUs, SSDs, and DDR memory, that perform computational tasks, and thus includes not only large server farms, internet servers, and bitcoin mining factories, but also small individual computers, internet servers, and computer gaming machines. Both large and small scale installations can benefit from the heat transfer methods of the present invention.

[0023] The term "semiconductor device" in this invention includes any electronic device that utilizes the properties of semiconductor material. Semiconductor devices are fabricated both as single devices and as integrated circuits consisting of many interconnected devices (starting from two and going up to billions) fabricated on a single semiconductor substrate or "wafer." The term "semiconductor device" includes both basic building blocks, such as diodes and transistors, to complex structures constructed from these basic blocks, ranging from analog, digital, and mixed-signal circuits, such as processors, memory chips, integrated circuits, circuit boards, phototubes and solar cells, sensors, etc. The term "semiconductor device" also includes any intermediate or unfinished product in the semiconductor industry derived from a wafer of semiconductor material.

[0024] The present invention provides a method for exchanging heat with a body comprising using a heat transfer fluid, said heat transfer fluid having the general formula: R f -O-CF2-O-CX=CYZ (I) (In the formula, -R f may be any C2-C6 linear or branched or C5C6 cyclic saturated carbon chain, which may be partially or fully fluorinated, and may contain 0 to 5 carbon atoms, all of which, if present, are involved in ether linkages; - X, Y, and Z may be independently selected from halogen or hydrogen, provided that at least one of X, Y, or Z is halogen. The present invention relates to a method comprising the step of:

[0025] Preferably, when X, Y and / or Z are halogen, they are selected from F and Cl, more preferably F.

[0026] R f If is partially fluorinated, R f It is preferred that the ratio of the number of fluorine atoms to the number of hydrogen atoms therein is at least 1.

[0027] More preferably, R f is the general formula: -CF2-CF2-R' (II) where R' is selected from -O-CF3, -F and -H.

[0028] Most preferably, said one or more compounds of formula (I) have the general formula: R'-CF2-CF2-O-CF2-O-CF=CF2 Particularly preferred compounds correspond to: CF3-CF2-O-CF2-O-CF=CF2, and CF3-O-CF2-CF2-O-CF2-O-CF=CF2 is.

[0029] Although this class of compounds is known and has been used, inter alia, in the polymerization of fluoroelastomers, their use as heat transfer fluids is new and has not previously been considered.

[0030] The art provides several methods for preparing compounds according to general formula (I). Examples of documents disclosing such methods include U.S. Patent Nos. 6,255,536 and 7,176,331 to Dyneon, and U.S. Patent Nos. 7,622,616 and 9,868,684 to Solvay. The method of the present invention can be used to exchange heat with any object. This method is particularly useful when the object is electronic computing equipment, such as a computer server. In fact, the method of the present invention can also be used in systems employing so-called "immersion cooling" or "direct contact cooling" because it uses a dielectric and noncorrosive heat transfer fluid. In these systems, the fluid is placed in direct contact with the electronic circuit board. At their operating temperatures, such fluids can be gases, liquids (single-phase immersion cooling), or in vapor-liquid equilibrium (i.e., near the boiling point of the liquid in so-called "two-phase immersion cooling").

[0031] In immersion cooling, electronic computing equipment such as CPUs, GPUs, memory, and other electronics, including complete servers, are completely immersed in a thermally conductive dielectric liquid or coolant, and its temperature is controlled using a circulation system that pumps the liquid through piping to a heat exchanger or radiator-type cooling device that rejects heat from the coolant.

[0032] Immersion cooling of servers is becoming a popular solution for server cooling, as it allows for significant reductions in energy usage by eliminating expensive air conditioning equipment. These systems are replaced with efficient low-speed liquid circulation pumps and simpler heat exchanger and / or radiator systems.

[0033] The temperature used in immersion cooling is determined by the maximum temperature at which the immersed equipment can reliably operate. For servers, this temperature range is typically 15-65°C, although in some cases this range can be extended to 75°C.

[0034] Current commercial applications of immersion cooling span data center-oriented solutions for commodity server cooling, server clusters, HPCC applications, and Bitcoin mining, as well as mainstream cloud-based and web hosting architectures. Immersion cooling is also used in the thermal management of computing equipment associated with LEDs, lasers, X-ray machines, and magnetic resonance imaging devices.

[0035] The method of the present invention is suitable for both single-phase and two-phase immersion cooling. In a single-phase immersion cooling system, the server is immersed in a bath of dielectric fluid. Heat is transferred to this liquid through direct contact with the electronic components. This fluid is usually maintained at a constant temperature through a recirculation system typical of thermostatic baths. More or less sophisticated control systems may exist to control the instantaneous temperature of the fluid and the temperature of the server to optimize the fluid temperature at each instant.

[0036] Two-phase immersion cooling is a technology sold by Allied Control and several other companies that involves submerging electronic devices in a sealed tank in a bath of dielectric fluid. This dielectric fluid has a boiling point that corresponds to a target temperature to which the bath can be set. When the electronic devices are heated to the boiling point of the dielectric fluid, the fluid transforms into a vapor, with heat subtracted from it. The vapor then condenses on a lid or coil condenser placed above the bath and re-deposits within the bath. This type of design is particularly valued because it does not require recirculation of the dielectric fluid and allows many more electronic devices to be accommodated in a small space.

[0037] Some of the compounds of the present invention according to general formula (I) have boiling points between 40°C and 90°C (see the Experimental section of the Examples below), making them particularly suitable for use in two-phase immersion cooling.

[0038] Furthermore, in the field of cooling computer equipment, the method of the present invention can also be used in non-immersion cooling systems in which a heat exchange fluid is circulated in a closed system and is in thermal contact with the processor through a plate of thermally conductive material (such as the server cooling solution manufactured by Ebullient under the name "Module Loop"). The use of a dielectric fluid is always beneficial, since there is always a risk of leakage and conductive liquids can have a destructive effect on electronic equipment.

[0039] The method of the present invention may also be useful in the semiconductor industry, where temperature control during the manufacture of semiconductor devices is critical, for example. In this case, the object exchanging heat with the heat transfer fluid is the semiconductor device. Temperature control units (TCUs) are all used along production lines for the fabrication of semiconductor devices and use heat transfer fluids to remove unwanted heat during steps such as wafer etching and deposition processes, ion implantation, and lithographic processes. Heat transfer fluids are typically circulated through the wafer pedestal and each process tool requiring temperature control has its own individual TCU.

[0040] Some particularly important tools that contain TCUs are silicon wafer etchers, steppers, and ashers. Etching is performed using reactive plasmas at temperatures ranging from 70°C to 150°C, and the wafer temperature must be precisely controlled throughout the temperature range during plasma processing. After plasma processing, the etched parts are typically immersed in a solvent that removes the etched parts. This second step is performed at moderate or ambient temperatures, so temperature control is typically not required. When we refer to an "etcher" in this application, we are referring to a device that performs plasma processing at high temperatures and therefore requires a TCU.

[0041] Steppers are used to photolithograph wafers to form reticle lines, which are then used to expose a photosensitive mask. This process is carried out at temperatures between 40°C and 80°C, and temperature control is crucial as the wafer must be maintained at a precise fixed temperature (±0.2°C) along the process to ensure good results.

[0042] Ashing is a process in which the photosensitive mask is removed from the wafer, performed at temperatures between 40°C and 150°C. The system uses plasma, and again, precise temperature control is particularly important.

[0043] Another related process is plasma-enhanced chemical vapor deposition (PECVD), in which a film of silicon oxide, silicon carbide, and / or silicon nitride is grown on the wafer in a chamber. Again, the temperature at which this step is carried out can be selected in the range of 50°C to 150°C, but the wafer must be held uniformly at the selected temperature throughout the deposition process.

[0044] In a semiconductor device manufacturing facility, typically each etcher, asher, stepper and plasma-enhanced chemical vapor deposition (PECVD) chamber has its own TCU through which heat transfer fluid is recirculated.

[0045] Another process step in which heat transfer fluids are used in the manufacture of semiconductor devices is vapor phase reflow (VPR) soldering. This is the most common method used to attach surface-mount devices, multichip modules, and hybrid components to circuit boards. In this method, the soldering material is applied in paste form, and then the semiconductor device, e.g., an unfinished circuit board, is placed in a sealed chamber containing a heat transfer fluid at its boiling point in equilibrium with its vapor phase. The vapor phase fluid transfers heat to the soldering paste, which then melts and stabilizes the contact. In this case, because the fluid is in direct contact with the circuit board, the fluid must be dielectric and noncorrosive. For this application, it is important that the heat transfer fluid contain a composition with a boiling point sufficient to melt the soldering paste.

[0046] Another system that is an important part of the manufacturing process for many semiconductor devices is thermal shock testing. In thermal shock testing, semiconductor devices are tested at two very different temperatures. While different standards exist, the test generally involves subjecting the semiconductor device to high and low temperatures and then testing the device's physical and electronic properties. Typically, the semiconductor device being tested is directly immersed alternately in a high-temperature bath (which can be at temperatures between 60°C and 250°C) and a low-temperature bath (which can typically be at temperatures between -10°C and -100°C). The transfer time between the two baths must be minimized, generally less than 10 seconds. Furthermore, in this test, the fluid comprising the bath is in direct contact with the device and therefore must be dielectric and noncorrosive. Additionally, to avoid contamination of the baths, it is highly preferred that the same fluid be used in both the low-temperature and high-temperature baths. Therefore, a heat transfer fluid that exists as a liquid over a wide temperature range is preferred.

[0047] Heat transfer fluids for use in the manufacture of semiconductor devices are typically liquids that exist in the liquid state over a wide temperature range, are dielectric, non-corrosive, and have relatively low viscosities that make them easily pumpable.

[0048] The method of the present invention can be used in all steps of semiconductor device manufacturing that require the semiconductor device to exchange heat with a heat transfer fluid, particularly when using semiconductor processing equipment such as etchers, ashers, steppers, and plasma-enhanced chemical vapor deposition (PECVD) chambers, each of which requires precise temperature control and / or heat dissipation and therefore is equipped with a temperature control unit (TCU) that can contain the selected heat transfer fluid of the method of the present invention.

[0049] Additionally, in thermal shock testing, an essential part of semiconductor device manufacturing, where only devices that pass the test are further processed, semiconductor devices are cooled and heated using at least two baths made of heat transfer fluids: a low-temperature bath, typically at temperatures between -10 and -100°C, and a high-temperature bath, typically at temperatures between 60 and 250°C. Advantageously, the method of the present invention can be used to select an appropriate compound or blend of compounds according to general formula (I) that constitutes the heat transfer fluid for the baths. Preferably, the heat transfer fluid should be selected so that the same heat transfer fluid can be used in both baths due to the wide temperature range over which the fluid is in its liquid state, thereby eliminating the risk of cross-contamination of the baths.

[0050] The method of the present invention can also find application in vapor phase soldering; indeed, the selected heat transfer fluid of the method of the present invention can be formulated to have a boiling point along the boiling point of the soldering paste, so that a semiconductor device containing a soldering paste that must further be "cured" can be introduced into a sealed chamber containing the selected heat transfer fluid of the method of the present invention at its boiling point in equilibrium with its heated vapor phase. The heated vapor will transfer heat to the semiconductor device, thereby melting the soldering paste and thus securing the contacts as required. For this application, a high-boiling point compound according to general formula (I) must be used in the heat transfer fluid.

[0051] An additional advantage is the ability to use a single heat transfer fluid for multiple applications, potentially enabling the use of a single heat transfer fluid throughout an entire semiconductor device manufacturing facility.

[0052] Another area in which the method of the present invention may be useful is in the thermal management of batteries, particularly rechargeable batteries such as vehicle batteries in cars, trams, trains and the like.

[0053] Recently, much of the industry-wide development in the field of rechargeable batteries has focused on lithium-ion batteries based on different types of lithium salts. Batteries based on lithium manganese oxide, lithium iron phosphate, and lithium nickel manganese cobalt oxide are used in applications such as vehicles, power tools, and electric bicycles. Lithium cobalt oxide-based batteries are typically used in smaller, less intensive applications, such as mobile phones, portable computers, and cameras. Batteries based on lithium nickel cobalt aluminum oxide and lithium titanate are being considered for applications requiring high power and / or capacity, such as electric powertrains and grid storage. Naturally, new technologies outside the realm of lithium-ion batteries are also being explored and constantly developed. The method of the present invention is not tied to a specific battery technology and is applicable to both current and next-generation battery systems.

[0054] Unlike conventional power systems, batteries, and particularly rechargeable batteries, have stringent requirements for their operating environment: Batteries tend to operate best within a relatively narrow temperature range.

[0055] Generally, low temperatures affect the chemical properties of the battery, slowing down reaction rates and therefore reducing the flow of electricity during charging or discharging. High temperatures increase reaction rates and simultaneously increase energy dissipation, thus generating even more excess heat, potentially causing an uncontrolled increase in temperature and potentially irreversible damage to the cell. In a typical Li-ion battery, temperatures exceeding 80°C in even a portion of its structure can initiate exothermic chemical reactions that cause further temperature increases in the battery, ultimately resulting in the complete destruction of the battery and the risk of fire and explosion.

[0056] On the other hand, practical applications of batteries require them to be efficient over a much wider temperature range. For example, vehicle batteries need to function properly in any environment in which people are expected to use them, and so they need to operate over a temperature range of -20°C to +40°C or more. In addition, the charge and discharge cycles of a battery can generate heat in the battery itself, making it even more difficult to maintain the battery within an acceptable temperature range.

[0057] Typical Li-ion battery labels indicate that the usable range is usually -20°C to 60°C, but good power output is only achieved between 0°C and 40°C, with optimal performance only achieved between 20°C and 40°C. Temperature also affects battery life; in fact, the number of charge / discharge cycles a battery can withstand before being considered depleted drops rapidly below 10°C due to anode plating and above 60°C due to electrode material degradation. The temperature range for optimal performance may vary for different battery chemistries and constructions; however, all current commercial batteries share a relatively narrow temperature range over which their performance is optimal. It is also generally important to ensure that the entire battery is maintained uniformly at the same temperature, without hot or cold regions, which can reduce its lifespan and safety.

[0058] For this reason, it is now common practice to incorporate battery thermal management systems (BTMS) into commercial battery assemblies, especially when battery safety, reliability, and lifespan are important concerns. These BTMS can be more or less complex depending on the type of battery; however, one common element is the presence of a heat transfer fluid, such as a gas or liquid, that exchanges heat with the battery, thus heating or cooling it.

[0059] Therefore, battery thermal management systems (BTMS) are particularly important in applications requiring high power and high reliability, such as vehicle batteries. While BTMSs can be more or less complex depending on the application, each BTMS at least functions to cool the battery when its temperature is too high or to heat the battery when its temperature is too low, typically using a heat transfer fluid that exchanges heat with the battery. Other common features of BTMSs are an insulation system to reduce the effect of the external environment on the battery temperature and a ventilation system to facilitate the dissipation of hazardous gases that may be present within the battery pack. However, the method of the present invention, which specifically relates to the heat exchange function of the BTMS, can be easily applied to any BTMS and can incorporate other functions and features.

[0060] BTMSs that use liquids as heat transfer fluids are common because liquids can transfer greater amounts of heat more quickly than gases. Typically, the fluid is circulated by a pump in a sealed system that is in thermal contact with the battery and a second system that functions to heat and / or cool the fluid to a desired temperature. This second system can include any combination of a cooling system and a heating system, or it can combine heating and cooling functions in a heat pump. The circulating fluid absorbs heat from or releases heat to the battery, and then it is circulated in the second system, returning the fluid to the desired temperature. There can be more or less sophisticated control systems that control the temperature of the fluid and the temperature of the battery to optimize the fluid's temperature at each instant.

[0061] In some systems, the fluid circulated within the system can therefore be in direct contact with the battery cells immersed therein. Clearly, in these cases, the fluid must be dielectric to protect the battery cells and their electronic components. In other cases, the heat transfer fluid is circulated within a separate, sealed system that simply exchanges heat by indirect contact, for example, via heat exchange plates made of metal or other thermally conductive materials. Since sealed systems have a high risk of leakage in any case, a dielectric fluid can also be advantageous in this type of system.

[0062] Particularly for high power batteries, where thermal management systems based on fluids, especially liquids, are used, the method of the present invention provides a reduced GWP 100 This provides improved thermal management in

[0063] Beyond the listed applications, the method of the present invention can also be adapted to any heat exchange method, such as heating or cooling compartments (e.g. food compartments), including those on aircraft, vehicle, or ship substrates, heating or cooling industrial production equipment, heating or cooling batteries during operation, forming thermostatic baths.

[0064] As mentioned in the introduction, heat transfer fluids used in these fields include fluorochemicals. Hydrofluoroethers in particular have found application in these fields due to their chemical inertness, dielectric properties, the fact that they are liquids and pumpable (typically having a viscosity of 1-50 cps at the temperature of use) with a wide T range, low flammability, and relatively low GWP.

[0065] Commercially available hydrofluoroethers for use in these areas, for example, combine all these properties with a relatively low GWP of about 70 to 300. 100 It is from 3M's Novec™ series, which combines

[0066] Furthermore, GWP has also become an important property in recent years due to the regulatory environment, and therefore there is a constant demand to develop new heat exchange fluids with even lower GWP than the currently commercialized hydrofluoroethers.

[0067] Applicant has unexpectedly found that the heat transfer fluids used in the method of the present invention are non-flammable, provide efficient heat transfer, can be used over a wide temperature range, and have dielectric and temperature properties that are equal to or improved over other materials commercialized as heat transfer fluids. Surprisingly, the heat transfer fluids used in the present invention have extremely low GWPs, generally below 30 and for some materials even below 3, as shown below in the experimental section. 100 This is a particularly unexpected result; indeed, previous reviews such as Hodnebrog et al. cited above did not study or suggest fluorinated vinyl ether compounds as low GWP compounds.

[0068] Therefore, using these selected compounds according to general formula (I), heat transfer fluids can be formulated having GWP100 values ​​of less than 30, preferably less than 10, and more preferably less than 5. Heat transfer fluids according to the present invention also have low toxicity and exhibit good heat transfer properties and relatively low viscosity over the entire range. Fluids of the present invention also have excellent electrical compatibility, i.e., they are non-corrosive, have high dielectric strength, high volume resistivity, and low solvency for polar materials. The electrical properties of the fluids of the present invention are such that they can be used in immersion cooling systems for electronics in direct contact with circuitry as well as in indirect contact applications using loops and / or conductive plates.

[0069] Heat transfer fluids for use in the process of the present invention preferably comprise more than 5 wt.%, more preferably more than 50 wt.%, and even more preferably more than 90 wt.% of one or more compounds according to the above formula (I). In one embodiment, the heat transfer fluid consists entirely of one or more compounds according to the above general formula.

[0070] In some embodiments, the heat transfer fluids of the present invention comprise a blend of compounds according to formula (I).

[0071] The method of the present invention can be applied to any heating and / or cooling system that uses a heat transfer fluid, particularly all of those exemplified herein, particularly for temperature control of electronic computing equipment, both in immersion cooling of such equipment where electronic circuit boards are directly immersed in a liquid, and in distribution systems where a fluid is distributed to a cooling element that can exchange heat with a substrate, such as a plate of a thermally conductive material, such as a metal or metal alloy.

[0072] Another application is the thermal management of batteries, especially rechargeable batteries for vehicles such as cars, trams, trains and the like.

[0073] Further applications are found in the semiconductor industry where the subject of heat exchange is a semiconductor device, such as temperature control units (TCUs) for etchers, ashers, steppers, and PECVD chambers, constant temperature ovens for thermal shock testing, and vapor phase soldering.

[0074] In another aspect, the present invention also encompasses an apparatus comprising an electronic computing device and a heat transfer fluid comprising one or more compounds having the general formula (I).

[0075] In a further aspect, the present invention relates to an apparatus comprising a battery, preferably a rechargeable battery, and a thermal management system for said battery, said thermal management system comprising a heat transfer fluid in heat exchange with said battery, said heat transfer fluid comprising one or more compounds having the general formula (I):

[0076] To the extent that the disclosure of any patents, patent applications, and publications incorporated herein by reference contradicts the statements of this application to the extent that the term may be unclear, the statements of this application shall control.

[0077] The present invention will now be described in more detail with reference to the following examples, the purpose of which is illustrative only and not intended to limit the scope of the invention.

[0078] standard: The electrical properties were measured according to the following standards. Dielectric Constant - ASTM D924-15 Specific Heat Capacity - ASTM E1269 [Example]

[0079] The following compounds Comparison A: CF3-CF2-O-CF2-O-CF=CF2 Comparison B: CF3-O-CF2-CF2-O-CF2-O-CF=CF2 were tested for flammability (both were found to be non-flammable, not flammable), and their thermal and dielectric properties were compared with other commercially available hydrofluoroethers and the fluorinated vinyl ether DCTFME [1,2-dichloro-1-fluoro-2-(trifluoromethoxy)-ethene] described in International PCT Patent Application EP 2020 / 057121 by Solvay Specialty Polymers Italy SpA.

[0080] [Table 2]

[0081] The results in Table 1 show that the compounds of the present invention have significantly better specific heat capacities, ensuring more efficient heat transfer. This is combined with other desirable properties (non-flammability, low GWP, and very low dielectric constant) that match other materials. This combination of properties makes the materials of the present invention particularly suitable as heat transfer fluids. Heat transfer fluids containing these compounds can be used in all of the applications mentioned, including heat exchange with electronic computing equipment, batteries, or semiconductor devices.

Claims

1. 1. A method for exchanging heat with a body comprising using a heat transfer fluid, the heat transfer fluid having the general formula: R ｆ -O-CF ２ -O-CX=CYZ (I) (In the formula, -R ｆ is any C which may be partially or fully fluorinated ２ ~C ６ or C ５ C ６ and may contain 0 to 5 carbon atoms, all of which, if present, are involved in ether linkages; X, Y, and Z can be independently selected from halogen or hydrogen, provided that at least one of X, Y, or Z is halogen. The method includes one or more compounds having the formula:

2. 10. The method of claim 1, wherein the one or more compounds of general formula (I) comprise at least 5% by weight of the heat transfer fluid.

3. The heat transfer fluid has a GWP of less than 30 １００ 3. The method of claim 1 or 2, comprising:

4. The method of any one of claims 1 to 3, wherein the object is an electronic computing device.

5. The method of claim 4 , wherein the electronic computing device is one or more servers.

6. 6. The method of claim 4 or 5, wherein the electronic computing device includes one or more electronic circuit boards, the method comprising directly contacting the electronic circuit boards with the heat transfer fluid.

7. The method according to any one of claims 4 to 6, which is a single-phase immersion cooling method.

8. The method according to any one of claims 4 to 6, which is a two-phase immersion cooling method.

9. The method of any one of claims 1 to 3, wherein the object is a battery.

10. The method according to any one of claims 1 to 3, wherein the object is a semiconductor device.

11. 11. The method of claim 10, using one or more semiconductor processing equipment selected from an etcher, an asher, a stepper, and a plasma-enhanced chemical vapor deposition (PECVD) chamber, wherein the semiconductor processing equipment includes at least one temperature control unit (TCU) in heat exchange with the semiconductor device, the TCU including a heat transfer fluid; The heat transfer fluid has the following general formula: R ｆ -O-CF ２ -O-CX=CYZ (I) (In the formula, -R ｆ is any C which may be partially or fully fluorinated ２ ~C ６ or C ５ C ６ and may contain 0 to 5 carbon atoms, all of which, if present, are involved in ether linkages; X, Y, and Z can be independently selected from halogen or hydrogen, provided that at least one of X, Y, or Z is halogen. The method of claim 1, further comprising one or more compounds having the formula:

12. 11. The method of claim 10, wherein the method is a method for thermal shock testing of a semiconductor device, and comprises, in any order: i. cooling said semiconductor device to a temperature comprised between −10° C. and −100° C. using a first bath made of a heat transfer fluid; ii. Heating said semiconductor device to a temperature comprised between 60°C and 250°C using a second bath made of a heat transfer fluid; Including, One or both of the first and second baths may be a compound having the general formula: R ｆ -O-CF ２ -O-CX=CYZ (I) (In the formula, -R ｆ is any C which may be partially or fully fluorinated ２ ~C ６ or C ５ C ６ and may contain 0 to 5 carbon atoms, all of which, if present, are involved in ether linkages; X, Y, and Z can be independently selected from halogen or hydrogen, provided that at least one of X, Y, or Z is halogen. The method of claim 1, wherein the heat transfer fluid is made of a heat transfer fluid comprising one or more compounds having the formula:

13. 11. The method of claim 10, wherein the method is a vapor phase soldering method for semiconductor devices, i. providing a semiconductor device containing a soldering paste; ii. providing an enclosed chamber containing a heat transfer fluid at its boiling point such that heated vapor of said heat transfer fluid is produced within said enclosed chamber; iii. introducing the semiconductor device into the sealed chamber in contact with the vapor of the heat transfer fluid, thereby melting the soldering paste upon contact with the heated vapor; Including, The heat transfer fluid has the following general formula: R ｆ -O-CF ２ -O-CX=CYZ (I) (In the formula, -R ｆ is any C which may be partially or fully fluorinated ２ ~C ６ or C ５ C ６ and may contain 0 to 5 carbon atoms, all of which, if present, are involved in ether linkages; X, Y, and Z can be independently selected from halogen or hydrogen, provided that at least one of X, Y, or Z is halogen. The method of claim 1, further comprising one or more compounds having the formula:

14. 1. An apparatus comprising an electronic computing device and a heat transfer fluid, the heat transfer fluid having the general formula: R ｆ -O-CF ２ -O-CX=CYZ (I) (In the formula, -R ｆ is any C which may be partially or fully fluorinated ２ ~C ６ or C ５ C ６ and may contain 0 to 5 carbon atoms, all of which, if present, are involved in ether linkages; X, Y, and Z can be independently selected from halogen or hydrogen, provided that at least one of X, Y, or Z is halogen.

10. A device comprising one or more compounds having the formula:

15. 1. An apparatus comprising a battery and a thermal management system for the battery, the thermal management system including a heat transfer fluid that exchanges heat with the battery, the heat transfer fluid having the general formula: R ｆ -O-CF ２ -O-CX=CYZ (I) (In the formula, -R ｆ is any C which may be partially or fully fluorinated ２ ~C ６ or C ５ C ６ and may contain 0 to 5 carbon atoms, all of which, if present, are involved in ether linkages; X, Y, and Z can be independently selected from halogen or hydrogen, provided that at least one of X, Y, or Z is halogen.

10. A device comprising one or more compounds having the formula:

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