Azeotropic composition of HFO-1234YF and hydrocarbons

Abstract

To provide low-GWP heat pump type fluids to meet the ever-increasing needs of hybrid, mild hybrid, plug-in hybrid and electric vehicles, electrified mass transport, and residential and commercial structures, for thermal management which can provide cooling and heating.SOLUTION: A refrigerant composition comprises: 2,3,3,3-tetrafluoropropene (HFO-1234yf); 0.01 to 1 wt.% of a stabilizer selected from tocopherol and d-limonene; and at least one of ethane (R-170) present in an amount of 1 to 36.5 wt.% and propane (R-290) present in an amount of 1 to 15 wt.%. The composition is near-azeotropic over the temperature range of -30°C to 40°C.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] (Technical field) The present invention is directed to azeotropic and near-azeotropic compositions of HFO-1234yf and propane (R-290), as well as azeotropic and near-azeotropic compositions of HFO-1234yf and ethane (R-170). [Background technology]

[0002] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 62 / 741,243, filed October 4, 2018, the entire contents of which are incorporated herein by reference.

[0003] (Background technology) The automotive industry is experiencing an architecture platform revitalization from using an internal combustion engine (ICE) for propulsion to using batteries for propulsion. This platform revitalization may significantly limit the size of the internal combustion engine (ICE) in hybrid, plug-in hybrid vehicles, or eliminate the ICE entirely in pure electric vehicles. Some vehicles still retain an ICE and are known as hybrid electric vehicles (HEVs) or plug-in hybrids electric vehicles (PHEVs) or mild hybrids electric vehicles (MHEVs). Vehicles that are fully electric and have no ICE are called fully electric vehicles (EVs). All HEVs, PHEVs, MHEVs, and EVs use at least one electric motor. This electric motor provides some form of propulsion to the vehicle that is typically provided by the internal combustion engine (ICE) found in gasoline / diesel vehicles.

[0004] In electric vehicles, the ICE is usually reduced in size (HEV, PHEV, or MHEV) or eliminated (EV) to reduce the vehicle weight and thereby increase the electric drive cycles. The primary function of the ICE is to provide propulsion for the vehicle, but also provides the necessary heat for the passenger compartment as a secondary function. Heating is usually required when the ambient conditions are below 10°C. In non-electric vehicles, there is excess heat from the ICE that can be captured and used to heat the passenger compartment. It should be noted that the ICE can function well at temperatures of -30°C, although it may take some time to heat up and generate heat. Thus, in electric vehicles, the reduction or elimination of the ICE size, combined with the need for heating and cooling of the passenger compartment and the battery management requirements, dictate the use of a heat pump type fluid, i.e., a heat transfer fluid or working fluid that can be used in heating mode and / or cooling mode to effectively heat the passenger compartment.

[0005] Environmental pressures are phasing out the current automotive refrigerant, R-134a, a hydrofluorocarbon or HFC, in favor of lower Global Warming Potential (GWP) refrigerants with GWP<150. HFO-1234yf, a hydrofluoroolefin, meets the low GWP requirements (GWP=4 per Papadimitriou, GWP<1 per AR5), but has low refrigeration capacity and typically cannot fully meet the needs at low (-10°C) to very low (-30°C) ambient temperatures without some type of system modification or working fluid change.

[0006] Similarly, stationary residential and commercial structural heating and cooling also suffers from a lack of suitable low GWP refrigerants to replace the older high GWP refrigerants currently in use.

[0007] Due to the method of repair or maintenance of the vehicle, the liquid gradient must be low or negligible. Currently, during the vehicle air conditioning repair or service process, the refrigerant is handled through a specific vehicle maintenance machine. This machine recovers the refrigerant, recycles the refrigerant to an intermittent quality level to remove gross contaminants, and recharges the vehicle with the refrigerant after the repair or maintenance is completed. These machines are called R / R / R machines because they recover, recycle, and recharge the refrigerant. In this on-site recovery, recycling, and recharging of refrigerant during vehicle maintenance or repair, low gradients are preferred, and negligible gradients are most preferred. Current vehicle maintenance machines are not set up to handle refrigerants with high or negligible gradients. Because the refrigerant is handled "on-site" at the vehicle repair shop, there is no opportunity to reconstitute blended refrigerants to the correct composition as refrigerant recyclers do. Refrigerants with high gradients may need to be "reconstituted" to the original formulation, or cycle performance will be compromised. This requirement of low or no gradients also applies to heat pump type fluids because heat pump fluids are handled and / or maintained in the same manner as conventional air conditioning fluids, and therefore refrigerants with low or no gradients are required in automotive applications. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] U.S. Provisional Patent Application No. 62 / 741,243 Summary of the Invention [Problem to be solved by the invention]

[0009] Therefore, low GWP heat pump type fluids are needed to meet the ever-increasing need for thermal management that can provide cooling and heating in hybrid, mild hybrid, plug-in hybrid and electric vehicles, electrified mass transportation, and residential and commercial structures. [Means for solving the problem]

[0010] The present invention relates to compositions of environmentally friendly refrigerant blends with ultra-low GWP (GWP ≦10 GWP), low toxicity (Class A according to ANSI / ASHRAE Standard 34 or ISO Standard 817), low temperature gradient (<3K) or nearly negligible gradient (<0.75K) and low flammability (Class 2 or Class 2L according to ASHRAE 34 or ISO 817) for use in vehicle cabin thermal management (transfer of heat from one part of the vehicle to another) to provide air conditioning (A / C) or heat the passenger compartment in hybrid, mild hybrid, plug-in hybrid, or fully electric vehicles. These refrigerants can also be used in mass transit mobile applications that benefit from heat pump type heating and cooling of the passenger compartment area. Mass transit mobile applications can include, but are not limited to, transportation vehicles such as ambulances, buses, shuttles, and trains.

[0011] The compositions of the present invention exhibit low temperature gradients over the operating conditions of a vehicle's thermal management system. In one embodiment of the present invention, the refrigerant composition comprises a mixture of HFO-1234yf and propane that exhibits near-azeotropic behavior. In one embodiment of the present invention, the refrigerant composition comprises a mixture of HFO-1234yf and ethane that exhibits azeotrope-like behavior.

[0012] The present invention includes the following aspects and embodiments. In one embodiment, disclosed herein are compositions useful as refrigerants and heat transfer fluids. The compositions disclosed herein include 2,3,3,3-tetrafluoropropene (HFO-1234yf) and at least one of ethane (R-170) or propane (R-290), where the compositions are near azeotropic.

[0013] Also disclosed herein are compositions that are azeotrope-like, according to any of the foregoing embodiments.

[0014] According to any of the foregoing embodiments, also disclosed herein is a composition having a 2,3,3,3-tetrafluoropropene (HFO-1234yf) concentration equal to or greater than the 2,3,3,3-tetrafluoropropene (HFO-1234yf) concentration of propane NAL1, and a 2,3,3,3-tetrafluoropropene (HFO-1234yf) concentration equal to or less than the 2,3,3,3-tetrafluoropropene (HFO-1234yf) concentration of propane NAH1.

[0015] According to any of the foregoing embodiments, also disclosed herein is a composition having a 2,3,3,3-tetrafluoropropene (HFO-1234yf) concentration greater than or equal to the 2,3,3,3-tetrafluoropropene (HFO-1234yf) concentration of propane ALL1 and a 2,3,3,3-tetrafluoropropene (HFO-1234yf) concentration less than or equal to the 2,3,3,3-tetrafluoropropene (HFO-1234yf) concentration of propane ALH1.

[0016] Also disclosed herein, according to any of the foregoing embodiments, is a composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane (R-290), wherein the propane (R-290) is present in an amount up to 22 weight percent based on the total refrigerant composition.

[0017] Also disclosed herein, according to any of the foregoing embodiments, is a composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane (R-290), wherein the propane (R-290) is from 1 to 20 weight percent based on the total refrigerant composition.

[0018] Also disclosed herein, according to any of the foregoing embodiments, is a composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane (R-290), wherein the propane (R-290) is from 1 to 10 weight percent based on the total refrigerant composition.

[0019] Also disclosed herein, according to any of the foregoing embodiments, is a composition, wherein the composition exhibits near-azeotropic properties over a temperature range of -30°C to 40°C.

[0020] Also disclosed herein, in accordance with any of the foregoing embodiments, is a composition, wherein the refrigerant composition is a heat pump fluid.

[0021] Also disclosed herein, according to any of the foregoing embodiments, is a composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane (R-290), wherein the propane (R-290) is from 1 to 5 weight percent based on the total refrigerant composition.

[0022] Also disclosed herein, according to any of the foregoing embodiments, is a composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane (R-290), wherein the propane (R-290) is from 1 to 2 weight percent based on the total refrigerant composition.

[0023] According to any of the foregoing embodiments, disclosed herein is also a refrigerant composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane (R-290), wherein the heat capacity of the refrigerant composition is 2% to 22% greater than the heat capacity of 2,3,3,3-tetrafluoropropene (HFO-1234yf) alone.

[0024] Also disclosed herein, according to any of the foregoing embodiments, is a refrigerant composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane (R-290), wherein the refrigerant composition has a GWP of less than 10 and an ODP of 0.

[0025] According to any of the foregoing embodiments, disclosed herein is also a refrigerant composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane (R-290), wherein the refrigerant composition has a GWP of less than 5.

[0026] According to any of the foregoing embodiments, also disclosed herein is a refrigerant composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane (R-290), the refrigerant composition having a temperature gradient of less than 0.35 Kelvin (K) from a temperature of -30°C up to 10°C.

[0027] According to any of the foregoing embodiments, also disclosed herein is a composition having a 2,3,3,3-tetrafluoropropene (HFO-1234yf) concentration greater than or equal to the 2,3,3,3-tetrafluoropropene (HFO-1234yf) concentration of ethane NAL1 and a 2,3,3,3-tetrafluoropropene (HFO-1234yf) concentration less than or equal to the 2,3,3,3-tetrafluoropropene (HFO-1234yf) concentration of ethane NAH1.

[0028] According to any of the foregoing embodiments, also disclosed herein is a composition having a 2,3,3,3-tetrafluoropropene (HFO-1234yf) concentration that is greater than or equal to the 2,3,3,3-tetrafluoropropene (HFO-1234yf) concentration in ethane ALL1 and a 2,3,3,3-tetrafluoropropene (HFO-1234yf) concentration that is less than or equal to the 2,3,3,3-tetrafluoropropene (HFO-1234yf) concentration in ethane ALH1.

[0029] Also disclosed herein, according to any of the foregoing embodiments, is a composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and ethane (R-170), wherein the ethane (R-170) is present in an amount up to 36.5 weight percent based on the total refrigerant composition.

[0030] Also disclosed herein, according to any of the foregoing embodiments, is a composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and ethane (R-170), wherein the ethane (R-170) is present in an amount up to 10 weight percent based on the total refrigerant composition.

[0031] Also disclosed herein, according to any of the foregoing embodiments, is a composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and ethane (R-170), wherein the ethane (R-170) is present in an amount from 1 to 7 weight percent based on the total refrigerant composition.

[0032] Also disclosed herein, according to any of the foregoing embodiments, is a composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and ethane (R-170), wherein the ethane (R-170) is present in an amount up to 5 weight percent based on the total refrigerant composition.

[0033] Also disclosed herein, according to any of the foregoing embodiments, is a composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and ethane (R-170), wherein the ethane (R-170) is present in an amount up to 1 weight percent based on the total refrigerant composition.

[0034] According to any of the foregoing embodiments, disclosed herein is also a refrigerant composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and ethane (R-170), wherein the heat capacity of the refrigerant composition is 5% to 70% greater than the heat capacity of 2,3,3,3-tetrafluoropropene (HFO-1234yf) alone.

[0035] According to any of the foregoing embodiments, disclosed herein is also a refrigerant composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and ethane (R-170), wherein the heat capacity of the refrigerant composition is 5% to 54% greater than the heat capacity of 2,3,3,3-tetrafluoropropene (HFO-1234yf) alone.

[0036] According to any of the foregoing embodiments, disclosed herein is also a refrigerant composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and ethane (R-170), wherein the refrigerant composition has a GWP of less than 10.

[0037] According to any of the foregoing embodiments, also disclosed herein is a refrigerant composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and ethane (R-170), the refrigerant composition having a temperature gradient of less than 3 Kelvin (K) at temperatures from -30°C up to 10°C.

[0038] Also disclosed herein, according to any of the foregoing embodiments, is a composition, wherein the ratio of the heat capacity of the refrigerant composition to the heat capacity of 2,3,3,3-tetrafluoropropene (HFO-1234yf) is from 1.05 to 1.50 at the same temperature and pressure.

[0039] In another embodiment, disclosed herein is a refrigerant composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane (R-290), wherein the propane (R-290) is present in an amount from 0.1 to 15 weight percent based on the total refrigerant composition.

[0040] In another embodiment, disclosed herein is a refrigerant composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane (R-290), wherein the propane (R-290) is present in an amount from 0.1 to 22 weight percent based on the total refrigerant composition.

[0041] According to any of the foregoing embodiments, disclosed herein is also a refrigerant composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane (R-290), wherein the heat capacity of the refrigerant composition is 2% to 22% greater than the heat capacity of 2,3,3,3-tetrafluoropropene (HFO-1234yf) alone.

[0042] Also disclosed herein, according to any of the foregoing embodiments, is a refrigerant composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane (R-290), wherein the refrigerant composition has a GWP of less than 10 and an ODP of 0.

[0043] According to any of the foregoing embodiments, disclosed herein is also a refrigerant composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane (R-290), wherein the refrigerant composition has a GWP of less than 5.

[0044] According to any of the foregoing embodiments, also disclosed herein is a refrigerant composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane (R-290), the refrigerant composition having a temperature gradient of less than 0.35 Kelvin (K) from a temperature of -30°C up to 10°C.

[0045] In another embodiment, disclosed herein is a heating system or cooling system or reversible cooling system or reversible heating system or heat pump system comprising a condenser, an evaporator, and a compressor operably connected in a series arrangement, wherein a refrigerant composition of any of the preceding embodiments is circulated through each of the condenser, evaporator, and compressor.

[0046] According to any of the aforementioned embodiments, also disclosed herein is a heating or cooling system, wherein the system is an air conditioner for an automotive system.

[0047] According to any of the aforementioned embodiments, also disclosed herein is a heating or cooling system, wherein the system is an air conditioner for a stationary cooling system.

[0048] In accordance with any of the foregoing embodiments, also disclosed herein is a heating or cooling system, further comprising a four-way valve.

[0049] According to any of the aforementioned embodiments, also disclosed herein is a heating or cooling system, wherein the system is a heat pump for an automotive system.

[0050] According to any of the aforementioned embodiments, also disclosed herein is a heating or cooling system, wherein the system is a heat pump for a stationary heating or cooling system.

[0051] According to any of the foregoing embodiments, also disclosed herein is a heating or cooling system, wherein the temperature gradient is less than 1 Kelvin (K).

[0052] According to any of the foregoing embodiments, also disclosed herein is the use of the refrigerant composition of any of the foregoing embodiments in a heat pump system, a reversible cooling loop system, or an independent heating system, or an independent cooling system.

[0053] According to any of the foregoing embodiments, also disclosed herein is the use of the refrigerant composition of any of the foregoing embodiments in a hybrid electric vehicle (HEV), mild hybrid electric vehicle (MHEV), plug-in hybrid electric vehicle (PHEV), or electric vehicle (EV) heat pump system.

[0054] According to any of the foregoing embodiments, also disclosed herein is the use of the refrigerant composition in a hybrid electric vehicle (HEV), a mild hybrid electric vehicle (MHEV), a plug-in hybrid electric vehicle (PHEV), or an electric vehicle (EV) heat pump system.

[0055] According to any of the foregoing embodiments, also disclosed herein is the use of the refrigerant composition in a HEV, MHEV, PHEV, or EV heat pump system in combination with a vehicle electrical system.

[0056] Also disclosed herein, in accordance with any of the preceding embodiments, is a method of charging a refrigerant composition into an automotive system, comprising providing a composition of any of the preceding embodiments to a heating or cooling system of the automotive vehicle.

[0057] Also disclosed herein, in accordance with any of the foregoing embodiments, is a method of servicing the refrigerant composition of any of the foregoing embodiments using conventional on-site vehicle recovery, recycling, and recharging equipment.

[0058] In another embodiment, a method of remediating total contaminants from a refrigerant composition disclosed herein includes the steps of providing a first refrigerant composition, the first refrigerant composition being not near azeotropic and comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and at least one of ethane (R-170) or propane (R-290); and providing at least one of 2,3,3,3-tetrafluoropropene (HFO-1234yf), ethane (R-170), or propane (R-290) to the first refrigerant composition to form a second refrigerant composition, the second refrigerant composition being near azeotropic.

[0059] Also disclosed herein, in accordance with any of the foregoing embodiments, is a method, wherein the second refrigerant composition is formed from the first refrigerant composition without the use of conventional on-site automated recovery, recycling, or recharging equipment.

[0060] Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, which illustrates, by way of example, the principles of the invention. [Brief description of the drawings]

[0061] [Figure 1] FIG. 2 shows vapor-liquid equilibrium properties of blends of HFO-1234yf and propane, according to one embodiment. [Diagram 2] FIG. 2 shows vapor-liquid equilibrium properties of blends of HFO-1234yf and propane, according to one embodiment. [Diagram 3] FIG. 2 shows vapor-liquid equilibrium properties of blends of HFO-1234yf and ethane, according to one embodiment. [Figure 4] FIG. 2 shows vapor-liquid equilibrium properties of blends of HFO-1234yf and ethane, according to one embodiment. [Diagram 5] FIG. 1 illustrates a reversible cooling or heating loop system, according to one embodiment. [Figure 6] FIG. 1 illustrates a reversible cooling or heating loop system, according to one embodiment. [Figure 7] FIG. 1 illustrates a reversible cooling or heating loop system, according to one embodiment. [Figure 8] FIG. 1 illustrates a reversible cooling or heating loop system, according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0062] definition As used herein, the term heat transfer composition means a composition used to transport heat from a heat source to a heat sink.

[0063] A heat source is defined as any space, location, thing, or object from which it is desirable to add, transfer, move, or remove heat. An example of a heat source in this embodiment is the passenger compartment of a vehicle, which requires air conditioning.

[0064] A heat sink is defined as any space, place, thing or object that can absorb heat. An example of a heat sink in this embodiment is the passenger compartment of a vehicle that requires heating.

[0065] A heat transfer system is a system (or equipment) used to produce a heating or cooling effect at a specific location. The heat transfer system of the present invention refers to a reversible heating or cooling system that provides passenger compartment heating or cooling. This system may also be called a heat pump system, a reversible heating loop, or a reversible cooling loop.

[0066] The heat transfer fluid includes at least one refrigerant and at least one member selected from the group consisting of a lubricant, a stabilizer, and a flame suppressant.

[0067] Refrigeration capacity (also called cooling capacity or heating capacity depending on the system's recommended requirements) is a term that defines the change in enthalpy of the refrigerant in the evaporator per kilogram of refrigerant circulating, or the heat removed by the refrigerant in the evaporator per unit volume (volume) of refrigerant vapor leaving the evaporator. Refrigeration capacity is a measure of the ability of a refrigerant or heat transfer fluid composition to produce cooling or heating. Thus, the higher the capacity, the more cooling or heating is produced. Cooling rate refers to the heat removed by the refrigerant in the evaporator per unit time. Heating rate refers to the heat removed by the refrigerant in the evaporator per unit time.

[0068] Coefficient of performance (COP) is the heat removed divided by the energy input required to run the cycle. The higher the COP, the more energy efficient the refrigerant or heat transfer fluid. COP is directly related to the Energy Efficiency Ratio (EER), which is a rating of the efficiency of a refrigeration or air conditioning unit at a particular combination of internal and external temperatures.

[0069] Subcooling refers to lowering the temperature of a liquid below its saturation point at a given pressure. The liquid saturation point is the temperature at which vapor completely condenses into a liquid. Subcooling continues to cool a liquid to a cooler liquid at a given pressure. Cooling a liquid below its saturation temperature (or boiling point temperature) can increase the net refrigeration capacity. Subcooling thereby increases the refrigeration capacity and energy efficiency of the system. The amount of subcooling is the amount of cooling below the saturation temperature (in degrees).

[0070] Superheating refers to raising the temperature of a vapor above its saturation point at a given pressure. The vapor saturation point is the temperature at which a liquid completely evaporates into a vapor. Superheating continues to heat a vapor to a hotter vapor at a given pressure. Heating the vapor above its saturation temperature (or dew point temperature) can increase the net refrigeration capacity. Superheating thereby increases the refrigeration capacity and energy efficiency of the system. The amount of superheat is the amount of heating above the saturation temperature (in degrees).

[0071] Temperature gradient (sometimes simply called "gradient") is the absolute value of the difference between the start and end temperatures of a phase change process by a refrigerant in a heat exchanger (evaporator or condenser) of a refrigerant system, excluding any subcooling or superheating. The term can be used to describe the condensation or evaporation of near-azeotropic or non-azeotropic compositions. When referring to the temperature gradient of an air conditioning or heat pump system, it is common to provide the average temperature gradient, which is the average of the temperature gradient in the evaporator and the temperature gradient in the condenser. Gradient can be applied to blended refrigerants, i.e., refrigerants composed of at least two components.

[0072] As used herein, the term low gradient should be understood to be less than 3 Kelvin (K) over the operating range of interest. In some embodiments, the gradient may be less than 2.5 K over the operating range of interest, or even less than 0.75 K over the operating range of interest.

[0073] Azeotropic compositions refer to constant boiling mixtures of two or more substances that behave as a single substance. One way to characterize an azeotropic composition is that the vapor produced by partial evaporation or distillation of a liquid has the same composition as the liquid that was evaporated or distilled (i.e., mixed distillate / reflux without compositional change). Constant boiling compositions are characterized as azeotropic because they exhibit either a maximum or minimum boiling point compared to non-azeotropic mixtures of the same compounds. During operation, azeotropic compositions do not fractionate within an air conditioning or heating system. Additionally, azeotropic compositions do not fractionate upon leakage from an air conditioning or heating system.

[0074] As used herein, the term "near azeotropic composition" is understood to mean a composition where the difference between the boiling point pressure (BP) and the dew point pressure (DP) of the composition at a particular temperature is 5% or less based on the boiling point pressure (i.e., [(BP-DP) / BP] x 100 <= 5).

[0075] As used herein, the term "azeotrope-like composition" is understood to mean a composition in which the difference between the boiling point pressure (BP) and the dew point pressure (DP) of the composition at a particular temperature is 3% or less based on the boiling point pressure (i.e., [(BP-DP) / BP] x 100 <= 3).

[0076] As used herein, the term "first near-azeotropic low HFO-1234yf composition (NAL1)" should be understood to mean the lowest concentration of HFO-1234yf in the composition range that exhibits near-azeotropic behavior of HFO-1234yf / propane or HFO-1234yf / ethane mixtures.

[0077] As used herein, the term "first near-azeotropic high HFO-1234yf composition (NAH1)" should be understood to mean the highest concentration of HFO-1234yf in the composition range that exhibits near-azeotropic behavior of HFO-1234yf / propane or HFO-1234yf / ethane mixtures.

[0078] As used herein, the term "first azeotrope-like low HFO-1234yf composition (ALL1)" should be understood to mean the lowest concentration of HFO-1234yf in the composition range that exhibits azeotrope-like behavior of HFO-1234yf / propane or HFO-1234yf / ethane mixtures.

[0079] As used herein, the term "first azeotrope-like high HFO-1234yf composition (ALH1)" should be understood to mean the highest concentration of HFO-1234yf in the composition range that exhibits azeotrope-like behavior of HFO-1234yf / propane or HFO-1234yf / ethane mixtures.

[0080] As used herein, the term "second near-azeotropic low HFO-1234yf composition (NAL2)" should be understood to mean the lowest concentration of HFO-1234yf in the composition range that exhibits near-azeotropic behavior of HFO-1234yf / propane or HFO-1234yf / ethane mixtures.

[0081] As used herein, the term "second near-azeotropic high HFO-1234yf composition (NAH2)" should be understood to mean the highest concentration of HFO-1234yf in the composition range that exhibits near-azeotropic behavior of HFO-1234yf / propane or HFO-1234yf / ethane mixtures.

[0082] As used herein, the term "second azeotrope-like low HFO-1234yf composition (ALL2)" should be understood to mean the lowest concentration of HFO-1234yf in the composition range that exhibits azeotrope-like behavior of HFO-1234yf / propane or HFO-1234yf / ethane mixtures.

[0083] As used herein, the term "second azeotrope-like high HFO-1234yf composition (ALH2)" should be understood to mean the highest concentration of HFO-1234yf in the composition range that exhibits azeotrope-like behavior of HFO-1234yf / propane or HFO-1234yf / ethane mixtures.

[0084] As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having," or any other variation thereof, are intended to cover non-exclusive inclusions. For example, a composition, process, method, article, or device that includes recited elements is not necessarily limited to only those elements, but may include other elements not expressly recited or associated with such composition, process, method, article, device, etc. Furthermore, unless expressly stated to the contrary, "or" refers to an inclusive "or," not an exclusive "or." For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or absent), A is false (or absent) and B is true (or present), and both A and B are true (or present).

[0085] The transitional phrase "consisting of" excludes any element, step, or ingredient not specified. When in a claim, such a phrase excludes the inclusion of materials other than those recited, except for impurities normally accompanying the materials. When the phrase "consisting of" appears within a clause in the body of a claim rather than immediately following the preamble, the phrase is intended to limit only the elements set forth in that clause and does not exclude other elements from the claim as a whole.

[0086] The transitional phrase "consisting essentially of" is used to define compositions, methods, and methods that include materials, steps, features, ingredients, or elements in addition to those literally disclosed, provided that these additionally included materials, steps, features, ingredients, or elements have a substantial effect on the basic and novel characteristics of the claimed invention, particularly the mode of action for achieving any desired result of the inventive process. The term "consisting essentially of" has a meaning intermediate between "comprising" and "consisting of."

[0087] It should be readily understood that where applicants have defined an invention or a portion thereof with open-ended terms such as "comprising," the description should be construed to also include inventions using the terms "consisting essentially of" or "consisting of" (unless otherwise expressly stated).

[0088] Additionally, the use of "a" or "an" is used to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be interpreted to include one or at least one, and the singular also includes the plural unless it is clear that a different meaning is intended.

[0089] Refrigerant Blends (Class A2, GWP<10 and 0 ODP) Global Warming Potential (GWP) is an index for estimating the relative global warming contribution due to the atmospheric emission of one kilogram of a particular greenhouse gas compared to the emission of one kilogram of carbon dioxide. GWP can be calculated for various time horizons and indicates the impact of a given gas's atmospheric lifetime. GWP for a 100-year time horizon is the value commonly referenced in the industry and is used herein. For fluid or refrigerant mixtures, a weighted average can be calculated based on the individual GWPs for each component. The United Nations' Intergovernmental Panel on Climate Control (IPCC) provides vetted values ​​for refrigerant GWPs in its official assessment reports (ARs). The fourth assessment report is designated AR4 and the fifth assessment report is designated AR5. Regulatory bodies currently use AR4 for official legislative purposes.

[0090] Ozone depletion potential (ODP) is a number that indicates the amount of ozone destruction caused by a substance. ODP is the ratio of a chemical's effect on the ozone compared to the effect of a similar mass of R-11 or fluorotrichloromethane. R-11 is a type of chlorofluorocarbon (CFC) that contains chlorine, which causes ozone destruction. Further, CFC-11 is defined as having an ODP of 1.0. Other CFCs and hydrofluorochlorocarbons (HCFCs) have ODPs ranging from 0.01 to 1.0. The hydrocarbons (HCs) and hydrofluoroolefins (HFOs) described herein have an ODP of zero because they do not contain chlorine, bromine, or iodine, species known to contribute to ozone decomposition and destruction. Hydrocarbons (HCs) also do not have an ODP because, by definition, they do not contain chlorine, bromine, or iodine.

[0091] The refrigerant blend composition comprises at least one hydrofluoroolefin, such as 2,3,3,3-tetrafluoropropene (HFO-1234yf), and at least one hydrocarbon, such as ethane (R-170) or propane (R-290).

[0092] Unsaturated hydrofluoroolefin (HFO) refrigerant components also have very low GWPs, with all HFO components having a GWP below 10. Hydrocarbon (HC) refrigerant components include ethane (R-170) or propane (R-290). The HC components also have very low GWPs; for example, ethane (R-170) has a GWP of 6 and propane (R-290) has a GWP of 3.

[0093] Therefore, the final blend has an ODP of 0 and a very low GWP, or a GWP of less than 10. Table 1, shown below, is a summary table showing the type, ODP, and GWP for 2,3,3,3-tetrafluoropropene (HFO-1234yf), ethane (R-170), propane (R-290), and various combinations thereof, as per the fourth and fifth assessments conducted by the Intergovernmental Panel on Climate Change (IPCC).

[0094] For a blend, the GWP can be calculated as a weighted average of the individual GWP values ​​in the blend, taking into account the amount (e.g., weight %) of each component (1-n) in the blend, as shown in equation (1).

[0095] Formula (1): GWP blend = amount 1 (GWP of component 1) + amount 2 (GWP of component 2) + amount n (GWP of component n).

[0096] The resulting GWPs of several blends subject to HFO-1234yf and R-170 are listed below. The blends with R-170 were limited to 36.5 wt%, so that the resulting blends met the ASHRAE Class 2 flammability requirements. Similarly, the resulting GWPs of several blends subject to HFO-1234yf and R-290 are listed below. The blends with R-290 were limited to 22 wt%, so that the resulting blends met the ASHRAE Class 2 flammability requirements. Because the GWPs of both HFO-1234yf and R-170 are so low, the final GWPs of blends containing up to 36.5 wt% R-170 will be less than 10, and even more preferably less than 5, based on IPCC AR4. Similarly, because the GWPs of both HFO-1234yf and R-190 are so low, the final GWPs of those containing up to 22 wt% R-290 will be less than 10, and even more preferably less than 5, and even less than 4, based on IPCC AR4.

[0097] [Table 1]

[0098] Refrigerant Lubricant The refrigerant or heat transfer composition of the present invention can be mixed with a lubricating oil and used as the "complete working fluid composition" of the present invention. The refrigerant composition of the present invention containing the heat transfer or working fluid and the lubricating oil of the present invention can contain publicly known additives such as stabilizers, leak detection materials, and other beneficial additives. The lubricating oil may also affect the flammability level of the resulting compound.

[0099] The lubricating oil selected for the composition preferably has sufficient solubility in the vehicle's A / C refrigerant to ensure that the lubricating oil can return from the evaporator to the compressor. Additionally, the lubricating oil preferably has a relatively low viscosity at low temperatures so that the lubricating oil can pass through the cold evaporator. In a preferred embodiment, the lubricating oil and the A / C refrigerant are miscible over a wide temperature range.

[0100] A preferred lubricant may be one or more polyol ester type lubricants (POE). As used herein, polyol ester includes compounds containing esters of diols or polyols having about 3 to 20 hydroxyl groups and fatty acids having about 1 to 24 carbon atoms, preferably used as polyols. Esters that can be used as base oils. (European patent application published according to Art. 153(4) EP 2 727 980(A1), which is incorporated herein by reference). Examples of diols include ethylene glycol, 1,3-propanediol, propylene glycol, 1,4-butanediol, 1,2-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 2-ethyl-2-methyl-1,3-propanediol, 1,7-heptanediol, 2-methyl-2-propyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol.

[0101] Examples of the polyol include polyhydric alcohols such as trimethylolethane, trimethylolpropane, trimethylolbutane, di(trimethylolpropane), tri(trimethylolpropane), pentaerythritol, di(pentaerythritol), tri(pentaerythritol), glycerin, polyglycerin (glycerin dimer to decamer), 1,3,5-pentanetriol, sorbitol, sorbitan, sorbitol-glycerin condensates, adonitol, arabitol, xylitol, mannitol, and the like; polysaccharides such as xylose, arabinose, ribose, rhamnose, glucose, fructose, galactose, mannose, sorbose, cellobiose, maltose, isomaltose, trehalose, sucrose, raffinose, gentianose, melezitose, and the like; partial etherification products thereof, and methyl glucoside, and the like. Among these, hindered alcohols such as neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, di(trimethylolpropane), tri(trimethylolpropane), pentaerythritol, di(pentaerythritol), or tri(pentaerythritol) are preferred as polyols.

[0102] The number of carbon atoms of the fatty acid is not particularly limited, but fatty acids having 1 to 24 carbon atoms are generally used. Among fatty acids having 1 to 24 carbon atoms, from the viewpoint of lubrication properties, fatty acids having 3 or more carbon atoms are preferred, fatty acids having 4 or more carbon atoms are more preferred, fatty acids having 5 or more carbon atoms are even more preferred, and fatty acids having 10 or more carbon atoms are most preferred. Furthermore, from the viewpoint of compatibility with the refrigerant, fatty acids having 18 or less carbon atoms are preferred, fatty acids having 12 or less carbon atoms are more preferred, and fatty acids having 9 or less carbon atoms are even more preferred.

[0103] Furthermore, the fatty acid may be either a straight-chain fatty acid or a branched-chain fatty acid, and from the viewpoint of lubrication properties, the straight-chain fatty acid is preferred, while from the viewpoint of hydrolysis stability, the branched-chain fatty acid is preferred.Furthermore, the fatty acid may be either a saturated fatty acid or an unsaturated fatty acid.Specifically, examples of the fatty acid include straight-chain or branched-chain fatty acids, such as pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid, icosanoic acid, oleic acid, and the like; and the so-called neo acid, in which a carboxylic acid group is bonded to a quaternary carbon atom. More specifically, preferred examples thereof include valeric acid (n-pentanoic acid), caproic acid (n-hexanoic acid), enanthic acid (n-heptanoic acid), caprylic acid (n-octanoic acid), pelargonic acid (n-nonanoic acid), capric acid (n-decanoic acid), oleic acid (cis-9-octadecanoic acid), isopentanoic acid (3-methylbutanoic acid), 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid, 3,5,5-trimethylhexanoic acid, etc. Incidentally, the polyol ester may be a partial ester in which the hydroxyl groups of the polyol are not completely esterified and remain; a complete ester in which all the hydroxyl groups are esterified; or a mixture of a partial ester and a complete ester, and a complete ester may be preferred in some cases.

[0104] In the polyol ester, from the viewpoint of better hydrolytic stability, esters of hindered alcohols such as neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, di(trimethylolpropane), tri(trimethylolpropane), pentaerythritol, di(pentaerythritol), tri(pentaerythritol) and the like are more preferred, and esters of neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, or pentaerythritol are even more preferred; from the viewpoint of particularly good compatibility with refrigerants and hydrolytic stability, esters of pentaerythritol are most preferred.

[0105] Specific preferred examples of polyol esters include diesters of neopentyl glycol and one or more fatty acids selected from valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, oleic acid, isopentanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid, and 3,5,5-trimethylhexanoic acid; triesters of trimethylolethane and one or more fatty acids selected from valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, oleic acid, isopentanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid, and 3,5,5-trimethylhexanoic acid; triesters of trimethylolpropane and one or more fatty acids selected from valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, oleic acid, isopentanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid, and 3,5,5-trimethylhexanoic acid; triesters of trimethylolbutane and one or more fatty acids selected from valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, oleic acid, isopentanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid, and 3,5,5-trimethylhexanoic acid; triesters of trimethylolbutane and one or more fatty acids selected from valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, oleic acid, isopentanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid, and 3,5,5-trimethylhexanoic acid; tetraesters of pentaerythritol and one or more fatty acids selected from valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, oleic acid, isopentanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid, and 3,5,5-trimethylhexanoic acid. Incidentally, the ester of two or more fatty acids may be a mixture of two or more esters of one fatty acid and a polyol, and an ester of two or more mixed fatty acids and a polyol. In particular, the ester of a mixed fatty acid and a polyol is excellent in low-temperature properties and compatibility with refrigerants.

[0106] In a preferred embodiment, the lubricant is soluble in the refrigerant at temperatures within the range of about −35° C. to about 100° C., more preferably about −30° C. to about 40° C., and even more specifically −25° C. to 40° C. In another embodiment, high temperature insolubility is not preferred, since attempting to maintain the lubricant within the compressor is not a priority.

[0107] Lubricants used for electric vehicle air conditioning applications may have a kinematic viscosity (measured at 40° C. according to ASTM D445) of 75 to 110 cSt, ideally about 80 cSt to 100 cSt, and most specifically 85 cSt to 95 cSt. However, without wishing to limit the invention, it should be noted that other lubricant viscosities may be used depending on the needs of the electric vehicle A / C compressor.

[0108] To limit hydrolysis of the lubricating oil, the water concentration in the heating / cooling systems of electric type vehicles must be controlled, and therefore the lubricant of this embodiment must be low in water, typically less than 100 ppm by weight.

[0109] Refrigerant Stabilizer Due to the presence of double bonds, HFO type refrigerants can be thermally unstable and decompose under extreme use, handling or storage conditions. It may therefore be advantageous to add stabilizers to HFO type refrigerants. Stabilizers may include, inter alia, nitromethane, ascorbic acid, terephthalic acid, azoles such as tolutriazole or benzotriazole, phenolic compounds such as tocopherol, hydroquinone, t-butylhydroquinone, 2,6-di-tertbutyl-4-methylphenol, epoxides (possibly fluorinated or perfluorinated alkyl epoxides or alkenyl or aromatic epoxides) such as n-butyl glycidyl ether, hexanediol diglycidyl ether, allyl glycidyl ether, butylphenyl glycidyl ether, terpenes such as d-limonene or alpha and beta-pinene, phosphites, phosphates, phosphonates, thiols and lactones.

[0110] Without wishing to be prescriptive, the blend may or may not contain a stabilizer, depending on the requirements of the system it is being used in. If the refrigerant blend does contain a stabilizer, it may contain any amount from 0.01 weight percent up to 1 weight percent of any of the stabilizers listed above, but most preferably is tocopherol or d-limonene.

[0111] Flammability of refrigerant blends Flammability is a term used to mean the ability of a composition to ignite and / or propagate a flame. For refrigerants and other heat transfer compositions or working fluids, the lower flammability limit ("LFL") is the lowest concentration of the heat transfer composition in air that can propagate a flame through a homogeneous mixture of the composition and air under the test conditions described in ASTM E681. The upper flammability limit ("UFL") is the highest concentration of the heat transfer composition in air that can propagate a flame through a homogeneous mixture of the composition and air under the same test conditions.

[0112] To be classified by ANSI / ASHRAE (American Society of Heating, Refrigeration and Air-Conditioning Engineers) as (Class 1, non-flammable), a refrigerant must meet the requirements of ASTM E681 when formulated in both the liquid and vapor phases, and must be non-flammable in both the liquid and vapor phases obtained in the event of a leak.

[0113] For a refrigerant to be classified as low flammable (Class 2L) by ANSI / ASHRAE (American Society of Heating, Refrigeration and Air-Conditioning Engineers), it must 1) exhibit flame spread when tested at 140°F (60°C) and 14.7 psia (101.3 kPa) and 2) have an LFL > 0.0062 lb / ft 3 (0.10kg / m 3), 3) has a maximum burning velocity of less than or equal to 3.9 in / sec (10 cm / sec) when tested at 73.4°F (23.0°C) and 14.7 psia (101.3 kPa), and 4) has a heat of combustion of less than 8169 Btu / lb (19,000 kJ / kg). 2,3,3,3-Tetrafluoropropene (HFO-1234yf) has a flammability rating of ANSI / ASHRAE Standard 34 Class 2L.

[0114] To classify a refrigerant as ANSI / ASHRAE Standard 34 Class 2, the refrigerant must: 1) exhibit flame propagation when tested at 140°F (60°C) and 14.7 psia (101.3 kPa); and 2) have an LFL > 0.0062 lb / ft 3 (0.10kg / m 3 ) and 3) has a heat of combustion of less than 8,169 Btu / lb (19,000 kJ / kg).

[0115] To classify a refrigerant as ANSI / ASHRAE Standard 34 Class 3, the refrigerant must: 1) exhibit flame propagation when tested at 140°F (60°C) and 14.7 psia (101.3 kPa); and 2) have an LFL of < 0.0062 lb / ft 3 (0.10kg / m 3 ) or 3) has a heat of combustion greater than 8,169 Btu / lb (19,000 kJ / kg).

[0116] When the HFO and HC components are blended in the correct ratios, the resulting blend has Class 2 flammability as defined by ANSI / ASHRAE Standard 34 and ISO 817. Class 2 flammability is inherently less flammable (i.e., lower energy release as exemplified by the heat of combustion or HOC value) than Class 3 flammability and can be managed in automotive heating / cooling systems. ASHRAE Standard 34 provides a method to calculate the heat of combustion of a refrigerant blend using a balanced stoichiometric equation based on the complete combustion of one mole of refrigerant with sufficient oxygen for the stoichiometric reaction.

[0117] As can be seen from the table below, which is based on heat of combustion calculations provided in ASHRAE Standard 34 Section 6.1.3.6, 0.1% to 36.5% by weight of ethane can be combined with HFO-1234yf and still meet the heat of combustion requirements for ASHRAE Class 2 flammability (HOC<19KJ / kg). Similarly, 0.1% to 22% by weight of propane can be combined with HFO-1234yf and still meet the heat of combustion requirements for ASHRAE Class 2 flammability (HOC<19KJ / kg).

[0118] [Table 2]

[0119] A blend containing 95 wt% R-1234yf and 5 wt% R-170 was tested according to ASTM E681 and found to have an LFL of 5% by volume. The resulting LFL meets ASHRAE Class 2 flammability requirements. See Table 3 below.

[0120] [Table 3]

[0121] When the HFO and HC components are blended in more precise ratios, the resulting blend has Class 2L flammability as defined by ANSI / ASHRAE Standard 34 and ISO 817. Class 2L flammability is inherently much less flammable (i.e., lower energy release as exemplified by the heat of combustion or HOC value) than Class 3 flammability and can be managed by automotive heating / cooling systems.

[0122] It is also possible to blend the HFO and HC components and add a flame suppressant such that the resulting blend has a Class 2L flammability as defined by ANSI / ASHRAE Standard 34 and ISO 817. Class 2L flammability is inherently much less flammable (i.e., lower energy release as exemplified by the heat of combustion or HOC value) than Class 3 flammability and can be managed in automotive heating / cooling systems. An example of this would be to add CF3I or other known flame suppressant such that the resulting blend has a Class 2L flammability without affecting the properties of the refrigerant blend. It is further possible to add enough flame suppressant to reduce the flammability such that the resulting blend is Class 1 and does not exhibit flame propagation.

[0123] The toxicity of these ingredients has also been reviewed by WEEL or similar toxicological type committees and found to have toxicity values ​​above 400 ppm, and therefore are classified as Class A or low toxicity level by ANSI / ASHRAE Standard 34 and ISO 817.

[0124] The compositions of the present invention are azeotrope-like and / or near azeotrope properties over the temperature ranges desired for use in thermal management systems. Azeotrope-like and / or near azeotrope compositions exhibit low temperature gradients when used in thermal management systems, such as refrigeration or air conditioning systems. In some embodiments, the compositions exhibit azeotrope-like and / or near azeotrope properties at both the desired evaporator and condenser operating temperatures.

[0125] The composition of the present invention can further improve the performance of heating / cooling systems. In some embodiments, the ratio of the heat capacity of the composition of the present invention to the heat capacity of 2,3,3,3-tetrafluoropropene (HFO-1234yf) is 1.05 to 1.50 at the same temperature and pressure.

[0126] Mixtures of HFO-1234yf and propane may exhibit azeotrope-like and / or near-azeotrope properties over one or more concentration ranges, depending on temperature and pressure. In some embodiments, refrigerant compositions of HFO-1234yf and propane may exhibit near-azeotrope properties over a concentration range from propane NAL1 to propane NAH1. In some embodiments, refrigerant compositions of HFO-1234yf and propane may exhibit azeotrope-like and / or near-azeotrope properties over a concentration range from propane NAL2 to propane NAH2. In some embodiments, the ranges from propane NAL1 to propane NAH1 and propane NAL2 to propane NAH2 overlap.

[0127] It will also be appreciated that compositions of the invention exhibiting near azeotropic properties may have an HFO-1234yf concentration as part of an HFO-1234yf / propane composition between the HFO-1234yf concentration corresponding to propane NAL1 and the HFO-1234yf concentration corresponding to propane NAH1. Similarly, compositions relating to propane NAL2, propane NAH2, and compositions exhibiting near azeotropic properties having an HFO-1234yf concentration between propane NAL2 and propane NAH2 may be as described above.

[0128] In some embodiments, refrigerant compositions of HFO-1234yf and propane may exhibit azeotrope-like properties over the concentration range from Propane ALL1 to Propane ALH1. In some embodiments, refrigerant compositions of HFO-1234yf and propane may exhibit azeotrope-like and / or near-azeotrope properties over the concentration range from Propane ALL2 to Propane ALH2. In some embodiments, the ranges Propane ALL1 to Propane ALH1 and Propane ALL2 to Propane ALH2 overlap.

[0129] It will also be appreciated that compositions of the invention exhibiting near azeotropic properties may have an HFO-1234yf concentration as part of an HFO-1234yf / propane composition between the HFO-1234yf concentration corresponding to AAL1 and the HFO-1234yf concentration corresponding to AAH1. Similarly, compositions relating to propane AAL2, propane AAH2, and compositions exhibiting near azeotropic properties having an HFO-1234yf concentration between propane AAL2 and propane AAH2 may be as described above.

[0130] Mixtures of HFO-1234yf and ethane (R-170) may exhibit azeotrope-like and / or near-azeotrope properties over one or more concentration ranges, depending on temperature and pressure. In some embodiments, refrigerant compositions of HFO-1234yf and ethane (R-170) may exhibit near-azeotrope properties over a concentration range from ethane NAL1 to ethane NAH1. In some embodiments, refrigerant compositions of HFO-1234yf and ethane (R-170) may exhibit azeotrope-like and / or near-azeotrope properties over a concentration range from ethane NAL2 to ethane NAH2. In some embodiments, the ranges from ethane NAL1 to ethane NAH1 and ethane NAL2 to ethane NAH2 do not overlap.

[0131] It will also be appreciated that compositions of the invention exhibiting near azeotropic properties may have an HFO-1234yf concentration as part of an HFO-1234yf / ethane (R-170) composition between the HFO-1234yf concentration corresponding to ethane NAL1 and the HFO-1234yf concentration corresponding to ethane NAH1. Similarly, compositions relating to ethane NAL2, ethane NAH2, and compositions exhibiting near azeotropic properties having an HFO-1234yf concentration between ethane NAL2 and ethane NAH2 may be as described above.

[0132] In some embodiments, refrigerant compositions of HFO-1234yf and ethane (R-170) may exhibit azeotrope-like properties over the concentration range from ethane ALL1 to ethane ALH1. In some embodiments, refrigerant compositions of HFO-1234yf and ethane (R-170) may exhibit azeotrope-like and / or near-azeotrope properties over the concentration range from ethane ALL2 to ethane ALH2. In some embodiments, the ranges from ethane ALL1 to ethane ALH1 and from ethane ALL2 to ethane ALH2 do not overlap.

[0133] It will also be appreciated that compositions of the invention exhibiting near azeotropic properties may have an HFO-1234yf concentration as part of an HFO-1234yf / ethane (R-170) composition between the HFO-1234yf concentration corresponding to ethane AAL1 and the HFO-1234yf concentration corresponding to ethane AAH1. Similarly, compositions relating to ethane AAL2, ethane AAH2, and compositions exhibiting near azeotropic properties having an HFO-1234yf concentration between ethane AAL2 and ethane AAH2 may be as described above.

[0134] One embodiment of the invention is shown in Figure 1. In the example of Figure 1, the percent deviation between the bubble point pressure and the dew point pressure based on the bubble point pressure of R-1234yf / propane at 0°C is shown. The system is near azeotropic from 0 Propane NAL1 (610) to about 70 weight percent R-1234yf Propane NAH1 (650) and from 100 to about 30 weight percent propane at a temperature of about 0°C. The system is also near azeotropic from about 98.5 Propane NAL2 (660) to 100 weight percent R-1234yf Propane NAH2 (640) and from about 1.5 to 0 weight percent propane at a temperature of about 0°C.

[0135] The system is azeotrope-like from 0 Propane ALL1 (615) to about 67.8 weight percent R-1234yf Propane ALH1 (620) and from 100 to about 32.2 weight percent propane at a temperature of about 0° C. The system is also azeotrope-like from about 99.2 Propane ALL2 (630) to 100 weight percent R-1234yf Propane ALH2 (645) and from about 0.8 to 0 weight percent propane at a temperature of about 0° C.

[0136] Another embodiment of the invention is shown in Figure 2. In the example of Figure 2, the percent deviation between the bubble point pressure and the dew point pressure based on the bubble point pressure of R-1234yf / propane at 40°C is shown. The system is near azeotrope from about 0 propane NAL1 (610) to about 79.8 weight percent R-1234yf propane NAH1 (650) and from 100 to about 20.2 weight percent propane at a temperature of about 40°C. The system is also near azeotrope from about 96.3 propane NAL2 (660) to 100 weight percent R-1234yf propane NAH2 (640) and from about 3.7 to 0 weight percent propane at a temperature of about 40°C.

[0137] The system is azeotrope-like from 0 Propane ALL1 (615) to about 73.7 weight percent R-1234yf Propane ALH1 (620) and from 100 to about 26.3 weight percent propane at a temperature of about 40° C. The system is also azeotrope-like from about 98.2 Propane ALL2 (630) to 100 weight percent R-1234yf Propane ALH2 (645) and from about 1.8 to 0 weight percent propane at a temperature of about 40° C.

[0138] In embodiments, the refrigerant blend includes 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane (R-290). In some embodiments, the refrigerant blend can consist of 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane (R-290). In some embodiments, the refrigerant blend can include a blend ranging from 1 weight percent propane to 10 weight percent propane. More specifically, the blend can contain 5 weight percent to 10 weight percent propane, and even more specifically, 5 weight percent to 7 weight percent propane.

[0139] One embodiment of the invention is shown in Figure 3. In the example of Figure 3, the percent deviation between the bubble point pressure and the dew point pressure based on the bubble point pressure of R-1234yf / ethane at 0°C is shown. The system is near azeotrope from 0 ethane NAL1 (710) to about 15.1 weight percent R-1234yf ethane NAH1 (750) and from about 100 to about 84.9 weight percent ethane at a temperature of about 0°C. The system is also near azeotrope from about 99.8 ethane NAL2 (760) to 100 weight percent R-1234yf ethane NAH2 (740) and from about 0.2 to 0 weight percent ethane at a temperature of about 0°C.

[0140] The system is azeotrope-like from 0 Ethane ALL1 (715) to about 10 weight percent R-1234yf Ethane ALH1 (720), and from 100 to about 90 weight percent ethane, at a temperature of about 0° C. The system is also azeotrope-like from about 99.9 Ethane ALL2 (730) to 100 weight percent R-1234yf Ethane ALH2 (745), and from about 0.1 to 0 weight percent ethane, at a temperature of about 0° C.

[0141] Another embodiment of the invention is shown in Figure 4. In the example of Figure 4, the percent deviation between the bubble point pressure and the dew point pressure based on the bubble point pressure of R-1234yf / ethane at 40°C is shown. The system is near azeotrope at a temperature of about 40°C from about 36 ethane NAL1 (710) to about 42 weight percent R-1234yf ethane NAH1 (750) and from about 64 to about 58 weight percent ethane. The system is also near azeotrope at a temperature of about 40°C from about 99.6 ethane NAL2 (760) to 100 weight percent R-1234yf ethane NAH2 (740) and from about 0.4 to 0 weight percent ethane.

[0142] The system is azeotrope-like from 36 Ethane ALL1 (715) to about 38.9 weight percent R-1234yf Ethane ALH1 (720) and from about 64 to about 61.1 weight percent ethane at a temperature of about 40° C. The system is also azeotrope-like from about 99.8 Ethane ALL2 (730) to 100 weight percent R-1234yf Ethane ALH2 (745) and from about 0.2 to 0 weight percent ethane at a temperature of about 40° C.

[0143] While HFO-1234yf can be used as an air conditioning refrigerant, it is limited in its ability to function as a heat pump type fluid, i.e., in cooling and heating modes or in a reversible cycle system. Thus, the refrigerants described herein uniquely provide improved capacity over HFO-1234yf in the heating operating range, extend the capacity of the lower heating range over HFO-1234yf down to -30°C, and uniquely exhibit low or nearly negligible slopes while exhibiting very low GWP and low to mild flammability. Thus, these refrigerants are most useful in electrified vehicle applications, particularly HEVs, PHEVs, MHEVs, EVs, and mass transit vehicles that require these properties at the lower heating range. It should also be noted that heat pump type fluids must also perform well in the air conditioning range, i.e., up to 40°C, providing increased capacity over HFO-1234yf. Thus, the refrigerant blends described herein can perform particularly well over a temperature range from -30°C up to +40°C and provide heating and / or cooling depending on the cycle being used in the heat pump system.

[0144] In embodiments, the refrigerant blend includes 2,3,3,3-tetrafluoropropene (HFO-1234yf) and ethane. In some embodiments, the refrigerant blend can consist of 2,3,3,3-tetrafluoropropene (HFO-1234yf) and ethane. In some embodiments, the refrigerant blend can include a near-azeotrope, azeotrope-like, or azeotrope blend including 2,3,3,3-tetrafluoropropene (HFO-1234yf) and ethane.

[0145] In other embodiments, the refrigerant blend comprises 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane. In some embodiments, the refrigerant blend can consist of 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane. In some embodiments, the refrigerant blend can comprise a near-azeotropic, azeotrope-like, or azeotropic blend comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane.

[0146] The refrigerant blends can be used in various heating and cooling systems. In the embodiment of FIG. 5, a heating / cooling system 100 with a heating / cooling loop 110 comprises a first heat exchanger 120, a pressure regulator 130, a second heat exchanger 140, a compressor 150, and a four-way valve 160. The first and second heat exchangers are of the air / refrigerant type. The refrigerant of the loop 110 and the air flow generated by the fan pass through the first heat exchanger 120. All or part of this same air flow can also pass through the heat exchanger to an external cooling circuit (not shown in FIG. 5), such as an engine. Similarly, the second heat exchanger 140 passes the air flow generated by the fan. All or part of this same air flow can also pass through another external cooling circuit (not shown in FIG. 5). The direction in which the air flows depends on the operating mode of the loop 110 and the requirements of the external cooling circuit. Thus, in the case of an engine, when the engine is idle and loop 110 is in heat pump mode, air can be heated by a heat exchanger in the engine cooling circuit and then blown over heat exchanger 120 to increase the rate of evaporation of the fluid in loop 110 and thus improve the performance of this loop. The heat exchanger in the cooling circuit can be actuated by a valve according to the engine requirements, such as heating the air entering the engine or productively using the energy generated by this engine.

[0147] In cooling mode, the refrigerant moved by the compressor 150 passes, via the valve 160, through the heat exchanger 120 functioning as a condenser, i.e. releasing thermal energy to the outside, then through the pressure regulator 130 and through the heat exchanger 140 functioning as an evaporator, thus cooling the flow of air intended to be blown into the interior of the passenger compartment of the vehicle.

[0148] In heat pump mode, the direction of refrigerant flow is reversed using valve 160. Heat exchanger 140 functions as a condenser and heat exchanger 120 functions as an evaporator. Heat exchanger 140 can then be used to heat a flow of air that is directed into the passenger compartment of the vehicle.

[0149] In the embodiment of Fig. 6, a heating / cooling system 200 with a heating / cooling loop 210 comprises a first heat exchanger 220, a pressure regulator 230, a second heat exchanger 240, a compressor 250, a four-way valve 260 and a branch 270, which, when considering the direction of the fluid flow in the cooling mode, is attached on the one hand to the outlet of the heat exchanger 220 and on the other hand to the outlet of the heat exchanger 240. This branch comprises a heat exchanger 280 through which passes the flow of air intended to enter the engine or the flow of exhaust gases, and a pressure regulator 280. The first heat exchanger 220 and the second heat exchanger 240 are of the air / refrigerant type. The refrigerant from the loop 210 and the air flow generated by the fan pass through the first heat exchanger 220. All or part of this same air flow also passes through a heat exchanger (not shown in Fig. 6) of the engine cooling circuit. Similarly, the second exchanger 240 passes the airflow brought by the fan. All or part of this airflow also passes through another heat exchanger of the engine cooling circuit (not shown in FIG. 6). The direction in which the air flows depends on the operating mode of the loop 210 and the engine requirements. As an example, when the combustion engine is idle and the loop 210 is in heat pump mode, the air can be heated by the heat exchanger of the engine cooling circuit and then blown against the heat exchanger 220 to accelerate the evaporation of the fluid of the loop 210 and improve the performance of this loop. The heat exchanger of the cooling circuit can be operated by a valve according to the engine requirements, such as heating the air entering the engine or productively using the energy generated by this engine.

[0150] The heat exchanger 280 can also be operated according to the energy requirements, whether it is in refrigeration mode or heat pump mode. A shutoff valve 290 can be installed in the branch 270 to activate or deactivate this branch.

[0151] The airflow delivered by the fan passes through heat exchanger 280. This same airflow may pass through other heat exchangers in the engine cooling circuit, and may also pass through other heat exchangers located in the exhaust gas circuit, the engine air inlet, or in the case of a hybrid vehicle, the battery.

[0152] In the embodiment of Fig. 7, a refrigeration system 300 with a refrigeration loop 310 comprises a first heat exchanger 320, a pressure regulator 330, a second heat exchanger 340, a compressor 350 and a four-way valve 360. The first heat exchanger 320 and the second heat exchanger 340 are of the air / refrigerant type. The way in which the heat exchangers 320 and 340 work is the same as in the first embodiment shown in Fig. 6. Two fluid / liquid heat exchangers 370 and 380 are installed both in the refrigeration loop circuit 310 and in the engine cooling circuit or the secondary glycol-water circuit. The installation of the fluid / liquid heat exchangers without passing an intermediate gaseous fluid (air) contributes to an improved heat exchange compared to an air / fluid heat exchanger.

[0153] In the embodiment of Fig. 8, a refrigeration system 400 with a refrigeration loop 410 comprises a first series of heat exchangers 420 and 430, a pressure regulator 440, a second series of heat exchangers 450 and 460, a compressor 470 and a four-way valve 480. A branch 490 is attached, when considering the circulation of the fluid in the refrigerant mode, to the outlet of the heat exchanger 420 on the one hand and to the outlet of the heat exchanger 460 on the other hand. This branch comprises a heat exchanger 500 through which passes the flow of air intended to enter the combustion engine or the flow of exhaust gases, and a shut-off valve 510. The way in which this branch works is the same as in the second embodiment shown in Fig. 7.

[0154] Heat exchangers 420 and 450 are of the air / refrigerant type, and heat exchangers 430 and 460 are of the liquid / refrigerant type. The way in which these heat exchangers work is the same as in the third embodiment shown in FIG.

[0155] Refrigerant blends can also be used to reduce the relative concentration of total contaminants from a refrigerant composition. In one embodiment, a first refrigerant composition comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and at least one of ethane (R-170) or propane (R-290) does not exhibit near-azeotropic behavior and is blended with at least one of 2,3,3,3-tetrafluoropropene (HFO-1234yf), ethane (R-170), or propane (R-290) to form a second refrigerant composition. The addition of at least one of 2,3,3,3-tetrafluoropropene (HFO-1234yf), ethane (R-170), or propane (R-290) reduces the relative concentration of total contaminants, resulting in a second refrigerant composition that exhibits near-azeotropic behavior. EXAMPLES

[0156] Comparison of thermodynamic modelling of heat pump systems. Heating mode: Ethane The thermodynamic modeling program, Thermocycle 3.0, was used to model the expected performance of HFO-1234yf / ethane blends compared to HFO-1234yf. The model conditions used for the heating mode were as follows: Heat exchanger #2 was varied in 10°C increments.

[0157] [Table 4]

[0158] Modeling results for HFO-1234yf / ethane in the range of 1 wt% to 10 wt%.

[0159] [Table 5]

[0160] [Table 6]

[0161] [Table 7]

[0162] [Table 8]

[0163] [Table 9]

[0164] Modeling results show that blends of HFO-1234yf with 1 wt% to 10 wt% R-170 provide significant advantages over pure HFO-1234yf. At ambient temperatures of -20°C and -30°C, HFO-1234yf does not perform well. At -30°C, the compressor inlet pressure is below atmospheric (less than 101.3 kPa) and air is drawn into the compressor (Table 4). Thus, HFO-1234yf is limited to use as a heat pump fluid down to -20°C without any system design. However, even 1 wt% R-170 (ethane) significantly improves the performance of the resulting blend, as HFO-1234yf (99 wt%) / R-170 (1 wt%) can operate at temperatures down to -30°C. Thus, the inventive blend of HFO-1234yf / R-170 extends the heating range by Δ10°C.

[0165] Blends of HFO-1234yf with 1 wt% to 10 wt% R-170 (ethane) also provide significant advantages over pure HFO-1234yf in terms of improved heating capacity. Modeling results indicate that even 1 wt% R-170 provides over 5% improvement in heat capacity, and up to 10% ethane can provide significant improvements in relative heat capacity up to 54%. The improved heating capacity of the inventive blends indicates that new fluids can be readily used to provide adequate heat to the passenger compartment. Furthermore, the resulting inventive blends generally have similar or reduced compressor discharge ratios versus pure HFO-2134yf over the operating range of the heat pump.

[0166] Modeling shows that blends of HFO-1234yf with 1 wt% to 5 wt% R-170 (ethane) have similar coefficient of performance (COP) or energy performance over the heating range of -30° C. to +10° C. Blends of HFO-1234yf with greater than 5 wt% up to 10 wt% R-170 (ethane) have adequate COP over the heating range.

[0167] Additionally, blends containing 1-10 wt% R-170 (ethane) also show relatively low gradients over the desired heating range, i.e., from -30°C up to 10°C. However, since servicing is typically performed in garage service bays where ambient temperatures are expected to be above 10°C, the R-170 blends have very good gradients and can be serviced as near azeotropic blends.

[0168] Thus, the HFO-1234yf / R-170 refrigerant blends described herein uniquely provide 5% to 54% improved capacity over HFO-1234yf in the -30°C to +10°C heating operating range, extend capacity in the lower heating range over HFO-1234yf by Δ10°C, and have a very low GWP (<10) and low to mild flammability (Class 2 to Class 2L), while also uniquely exhibiting low or nearly negligible temperature gradients in the automotive service temperature zone above 10°C.

[0169] While all blends of HFO-1234yf and R-170 are desirable, preferred blends having favorable flammability for a heat pump fluid (i.e., Class 2 or Class 2L) are 99% by weight HFO-1234yf to 63.5% by weight HFO-1234yf and 1% by weight R-170 to 36.5% by weight R-170, more preferred blends are 99% by weight HFO-1234yf to 90% by weight HFO-1234yf and 1% by weight to 10% by weight R-170, and most preferred blends are 99% by weight HFO-1234yf to 93% by weight HFO-1234yf and 1% by weight R-170 to 7% by weight R-170.

[0170] Heating mode: Propane The thermodynamic modeling program, Thermocycle 3.0, was used to model the expected performance of HFO-1234yf / propane blends compared to HFO-1234yf. The model conditions used for the heating mode were as follows: Heat exchanger #2 was varied in 10°C increments.

[0171] [Table 10]

[0172] Modeling results for HFO-1234yf / propane in the range of 1 wt% to 10 wt%.

[0173] [Table 11]

[0174] [Table 12]

[0175] [Table 13]

[0176] [Table 14]

[0177] [Table 15]

[0178] Modeling results show that blends of HFO-1234yf with 1 wt% to 10 wt% R-290 provide significant advantages over pure HFO-1234yf. At ambient temperatures of -30°C, HFO-1234yf does not perform well. The compressor inlet pressure is below atmospheric (less than 101.3 kPa) and air is drawn into the compressor (Table 4). Thus, HFO-1234yf is limited to use as a heat pump fluid down to -20°C without some system design. However, even 1 wt% R-290 (propane) significantly improves the performance of the resulting blend, as HFO-1234yf (99 wt%) / R-290 (1 wt%) can operate at temperatures down to -30°C. Thus, the inventive blend of HFO-1234yf / R-290 extends the heating range by Δ10°C.

[0179] Blends of HFO-1234yf with 1 wt% to 10 wt% R-290 (propane) also provide significant advantages over pure HFO-1234yf in terms of improved heating capacity. Modeling results indicate that even 1 wt% R-290 provides over 2% improvement in heat capacity, and up to 10% propane can provide significant improvements in relative heat capacity up to 22%. The improved heating capacity of the inventive blends indicates that new fluids can be readily used to provide adequate heat to the passenger compartment. Furthermore, the resulting inventive blends generally have similar or reduced compressor discharge ratios versus pure HFO-2134yf over the operating range of the heat pump.

[0180] Modeling shows that blends of HFO-1234yf with 1 wt% to 5 wt% R-290 (propane) have similar COP or energy performance over the heating range of -30° C. to +10° C. Blends of HFO-1234yf with greater than 5 wt% up to 10 wt% R-290 (propane) have adequate COP over the heating range.

[0181] Furthermore, blends containing 1-10 wt% R-290 (propane) also exhibit negligible gradients over the desired heating range, i.e., from -30° C. up to 10° C. Thus, the blends of the present invention can be used in almost any ambient environment.

[0182] Thus, the HFO-1234yf / R-290 refrigerant blends described herein uniquely provide 2% to 22% improved capacity over HFO-1234yf in the -30°C to +10°C heating operating range, a Δ10°C extension of capacity in the lower heating range over HFO-1234yf, and have a very low GWP (<10) and low to mild flammability (Class 2 to Class 2L), while also uniquely exhibiting near negligible slopes at all heat pump operating temperatures.

[0183] While all blends of HFO-1234yf and R-290 are desirable, preferred blends having favorable flammability for heat pump fluids are from 99% by weight HFO-1234yf to 78% by weight HFO-1234yf and 1% by weight R-290 to 22% by weight R-290, more preferred blends are from 99% by weight HFO-1234yf to 80% by weight HFO-1234yf and 1% by weight to 20% by weight R-290, and most preferred blends are from 99% by weight HFO-1234yf to 90% by weight HFO-1234yf and 1% by weight R-290 to 10% by weight R-290.

[0184] Cooling mode (propane) Comparison of thermodynamic modelling of heat pump systems.

[0185] Cooling mode: Propane The thermodynamic modeling program, Thermocycle 3.0, was used to model the expected performance of the blends for HFO-1234yf compared to HFO-1234yf / ethane. The model conditions used for the cooling mode were as follows: Heat exchanger #2 was varied in 10°C increments.

[0186] [Table 16]

[0187] [Table 17]

[0188] [Table 18]

[0189] [Table 19]

[0190] For a heat pump fluid to be a viable candidate, it must also perform well in cooling mode; i.e., provide adequate cooling when ambient temperatures are high. Modeling results show that blends of HFO-1234yf with 1% to 10% by weight R-290 offer significant advantages over pure HFO-1234yf in the cooling range from ambient temperatures of 20°C up to 40°C.

[0191] Blends of HFO-1234yf with 1 wt% to 10 wt% R-290 (propane) also provide significant advantages over pure HFO-1234yf in terms of improved cooling capacity. Modeling results indicate that even 1 wt% R-290 provides over 2% heat capacity improvement, and up to 10% propane can significantly improve relative cooling capacity up to 22%. The improved cooling capacity of the inventive blends indicates that new fluids can be readily used to provide adequate cooling (air conditioning) to the passenger cabin. Furthermore, the resulting inventive blends generally have similar compressor discharge ratios to pure HFO-1234yf across the cooling operating range.

[0192] Modeling indicates that blends of HFO-1234yf with 1 wt% to 10 wt% R-290 (propane) have similar COP or energy performance in the cooling range of +20°C to +40°C.

[0193] Furthermore, blends containing 1-10 wt% R-290 (propane) also exhibit negligible gradients over the desired cooling range, i.e., +20° C. to +40° C. Thus, the blends of the present invention can be used in almost any ambient environment.

[0194] Thus, the HFO-1234yf / R-290 refrigerant blends described herein uniquely provide 2% to 22% improved capacity over HFO-1234yf over the cooling operating range of +20°C to +40°C, and uniquely exhibit very low GWP (less than 10) and low to mild flammability (Class 2 to Class 2L), while also exhibiting near negligible gradients across all heat pump operating temperatures.

[0195] While all blends of HFO-1234yf and R-290 are desirable, preferred blends having favorable flammability (Class 2 or Class 2L) for heat pump (i.e., operating in heating or cooling mode) fluids are 99% by weight HFO-1234yf to 78% by weight HFO-1234yf and 1% by weight R-290 to 22% by weight R-290, more preferred blends are 99% by weight HFO-1234yf to 80% by weight HFO-1234yf and 1% by weight to 20% by weight R-290, and most preferred blends are 99% by weight HFO-1234yf to 90% by weight HFO-1234yf and 1% by weight R-290 to 10% by weight R-290.

[0196] Cooling mode: Ethane The thermodynamic modeling program, Thermocycle 3.0, was used to model the expected performance of the blends for HFO-1234yf compared to HFO-1234yf / propane. The model conditions used for the cooling mode were as follows: Heat exchanger #2 was varied in 10°C increments.

[0197] [Table 20]

[0198] [Table 21]

[0199] [Table 22]

[0200] [Table 23]

[0201] For a heat pump fluid to be a viable candidate, it must also perform well in cooling mode, i.e., provide adequate cooling when ambient temperatures are high. Modeling results show that blends of HFO-1234yf with 1% to 10% by weight R-170 offer significant advantages over pure HFO-1234yf in the cooling range from ambient temperatures +20°C up to +40°C.

[0202] Blends of HFO-1234yf with 1 wt% to 10 wt% R-170 (ethane) also provide significant advantages over pure HFO-1234yf in terms of improved cooling capacity. Modeling results indicate that even 1 wt% R-170 provides over 6-7% heat capacity improvement, and up to 10% ethane can significantly improve relative cooling capacity up to 50-70%. The improved cooling capacity of the inventive blends indicates that the new fluids can be readily used to provide adequate cooling (air conditioning) to the passenger cabin. Additionally, the resulting inventive blends generally have similar compressor discharge ratios to pure HFO-1234yf across the cooling operating range.

[0203] Modeling indicates that blends of HFO-1234yf with 1 wt% to 10 wt% R-170 (ethane) have similar COP or energy performance in the cooling range of +20°C to +40°C.

[0204] Furthermore, blends containing 1-10 wt% R-170 (ethane) also exhibit negligible gradients over the desired cooling range, i.e., +20° C. to +40° C. Thus, the blends of the present invention can be used in almost any ambient environment.

[0205] Thus, the HFO-1234yf / R-170 refrigerant blends described herein uniquely provide 2% to 22% improved capacity over HFO-1234yf over the +20 to +40°C cooling operating range, and uniquely exhibit very low GWP (less than 10) and low to mild flammability (Class 2 to Class 2L), while also exhibiting near negligible gradients across all heat pump operating temperatures.

[0206] While all blends of HFO-1234yf and R-170 are desirable, preferred blends having favorable flammability for heat pump fluids are 99% by weight HFO-1234yf to 63.5% by weight HFO-1234yf and 1% by weight R-170 to 36.5% by weight R-170, more preferred blends are 99% by weight HFO-1234yf to 90% by weight HFO-1234yf and 1% by weight to 10% by weight R-170, and most preferred blends are 99% by weight HFO-1234yf to 93% by weight HFO-1234yf and 1% by weight R-170 to 7% by weight R-170.

[0207] Although the present invention has been described with reference to preferred embodiments, those skilled in the art will recognize that various changes can be made without departing from the scope of the invention and that equivalents can be substituted for its elements. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is not intended that the invention be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but the invention is intended to include all embodiments falling within the scope of the appended claims.

Claims

1. A refrigerant composition comprising: 2,3,3,3-tetrafluoropropene (HFO-1234yf), 0.01 to 1 weight percent of a stabilizer selected from d-limonene or tocopherol; at least one of ethane (R-170), present in an amount of 1 to 36.5 weight percent, or propane (R-290), present in an amount of 1 to 15 weight percent; wherein the composition is near azeotropic over a temperature range of -30°C to 40°C.

2. 2. The composition of claim 1 comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane (R-290), wherein the refrigerant composition has a GWP less than 10 and an ODP of 0.

3. 3. The composition of claim 2 comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane (R-290), wherein the refrigerant composition has a GWP of less than 5.

4. 10. The composition of claim 1 comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane (R-290), said refrigerant composition having a temperature gradient of less than 0.35 Kelvin (K) from -30°C up to 10°C.

5. 10. The composition of claim 1 comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and ethane (R-170), wherein the ethane (R-170) is present in an amount up to 36.5 weight percent based on the total refrigerant composition.

6. 6. The composition of claim 5, wherein the ethane (R-170) is present in an amount up to 10 weight percent based on the total refrigerant composition.

7. 7. The composition of claim 6, wherein the ethane (R-170) is present in an amount of 1 to 7 weight percent based on the total refrigerant composition.

8. 8. The composition of claim 7, wherein the ethane (R-170) is present in an amount up to 5 weight percent based on the total refrigerant composition.

9. 9. The composition of claim 8, wherein the ethane (R-170) is present in an amount up to 1 weight percent based on the total refrigerant composition.

10. 2. The composition of claim 1, comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and ethane (R-170), wherein the heat capacity of the refrigerant composition is 5% to 70% greater than the heat capacity of 2,3,3,3-tetrafluoropropene (HFO-1234yf) alone.

11. A refrigerant composition comprising: 2,3,3,3-tetrafluoropropene (HFO-1234yf), 0.01 to 1 weight percent of a stabilizer selected from d-limonene or tocopherol; Propane (R-290) and wherein the propane (R-290) is present in an amount of 1 to 15 weight percent based on the total refrigerant composition.

12. 12. The composition of claim 11 comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane (R-290), wherein the refrigerant composition has a GWP less than 10 and an ODP of 0.

13. 12. The composition of claim 11 comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane (R-290), wherein the refrigerant composition has a GWP of less than 5.

14. 12. The composition of claim 11 comprising 2,3,3,3-tetrafluoropropene (HFO-1234yf) and propane (R-290), said refrigerant composition having a temperature gradient of less than 0.35 Kelvin (K) from -30°C up to 10°C.

15. 13. Use of the refrigerant composition of claim 1 in a HEV, MHEV, PHEV, or EV heat pump system in combination with a vehicle electrical system.

16. 13. A method for servicing the refrigerant composition of claim 1 using conventional on-site vehicle recovery, recycling and recharging equipment.

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