heat pump refrigerant

Abstract

A refrigerant comprising or essentially comprising: a) a non-flammable, high-volatile component comprising carbon dioxide; and b) a non-flammable, low-volatile component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1233zd(E), HFO1233zd(Z), HFO1233xf, HFO1336mzz(E), HFO1336mzz(Z), 2-bromo-3,3,3-trifluoroprop-1-ene and mixtures thereof; c) a medium-volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO1225ye(Z), HFO1243zf and mixtures thereof; and d) optionally a component selected from the group consisting of HFC227ea, HFC152a, HFC32 and mixtures thereof.

Description

Technology Field

[0001] The present invention relates to a refrigerant for a heat pump having a broad intrinsic glide and a very broad glide refrigerant composition, in particular, without limitation, a composition having a GWP of less than 400, preferably less than 150, more preferably less than 10. The refrigerant may be used in various applications including refrigeration, air conditioning, and heat pumping processes. These applications are collectively known as heat pumping. Background Technology

[0002] An embodiment of the present invention operates a Reverse Rankine Cycle (RRC).

[0003] RRC equipment is well known to technicians in the relevant technical field. The simplest form consists of an evaporator where a two-phase liquid / vapor refrigerant evaporates at low pressure and temperature, absorbing heat from adjacent heat sinks. The vapor from the evaporator is drawn into a compressor where it is compressed to high pressure and high temperature. The vapor then enters a condenser and is discharged onto adjacent heat sinks to condense into liquid. The high-pressure, high-temperature liquid passes through an expansion device to reduce its pressure to the evaporator pressure, and a portion of the liquid evaporates to lower its temperature. The two-phase mixture of liquid and vapor enters the evaporator and continues its circulation.

[0004] Another name for RRC is the Vapor Recompression Compression (VRC) cycle.

[0005] A xeotropic refrigerant composition evaporates and condenses over a temperature range at a constant pressure. This range is referred to as the 'temperature glide' or simply 'glide'. However, confusingly different definitions of the term 'glide' may be found in the prior art. For example, the term 'glide' may be defined as the temperature difference between the bubble point and the dew point at a specified constant pressure. A "glide" defined in this way is a purely thermodynamic property of the refrigerant and is independent of equipment and operating conditions. In this specification, the difference between the bubble point and the dew point at an absolute pressure of 1 atmosphere is referred to as the 'thermodynamic glide' of the blend.

[0006] Alternatively, in an evaporator, 'glide' can refer to the difference between the inlet temperature and the dew point; this value is inevitably smaller than the thermodynamic glide and depends on operating conditions, equipment design, and the composition of the blend. In a condenser, the glide is the difference between the dew point and the bubble point, and this also depends on operating conditions, equipment design, and the composition of the blend.

[0007] In this specification, the term “inherent temperature glide” refers to the temperature difference between the start and end points of a two-phase heat transfer region in an evaporator or condenser, assuming there is no pressure drop. When the evaporator or condenser is ‘flooded,’ both the liquid and vapor phases exist simultaneously along the entire length of the DX heat exchanger coil, where the glide is the temperature difference between the heat exchanger end points. This value will be smaller than the value provided by the previous definition.

[0008] In some thermal heat pumps, refrigerant glide can be utilized to improve performance by employing the development of an RRC / VRC known as the Lorentz Cycle. In this specification, the designation RRC / VRC also encompasses the Lorentz Cycle.

[0009] In this specification, thermodynamic temperature glides may be classified as follows:

[0010] 1. Negligible glide - Less than 0.5K

[0011] 2. Small glide - 0.5K to 2.0K

[0012] 3. Intermediate Glide - Over 2.0K to 5.0K

[0013] 4. Wide Glide - Over 5K to 10.0K

[0014] 5. Very wide glide - exceeding 10.0K

[0015] The composition of the present invention may have a wide or very wide thermodynamic temperature glide.

[0016] In actual heat exchangers, there is inevitably a pressure drop to maintain refrigerant flow. This results in a 'pressure-induced temperature glide'. The intrinsic glide and the pressure-induced glide combine to provide the actual glide. In the evaporator, the intrinsic glide and the pressure-induced glide act in opposite directions, so the actual temperature glide is smaller than the intrinsic temperature glide in the evaporative two-phase region. However, in the condensing two-phase flow region, the intrinsic glide and the pressure-induced glide act in the same direction. Therefore, they are additive, so that the actual temperature glide is greater than the intrinsic temperature glide. For convenience in this specification, the term "glide" will be considered to mean "intrinsic temperature glide" unless otherwise indicated. This meaning follows the custom and practice of those skilled in the art, where the contribution of the pressure-induced glide is often ignored. If the net glide resulting from the combination of the intrinsic glide and the pressure-induced glide is being considered, it will be referred to as the 'actual glide'.

[0017] If a xeotrope is registered with the American Society of Heating and Refrigeration Engineers (ASHRAE), it is assigned an "R4XX" number. Some blends are officially xeotropes, e.g., R404A and R410A, but they typically have a glide of less than 1K and are classified as "near-azeotropes." For practical purposes, they may be treated as azeotropic mixtures.

[0018] It is a common belief that azeotropic mixture-like compositions having a glide of less than 5K, preferably less than 1K, are necessary for the efficient and stable operation of heat pumping systems. The inventors have unexpectedly discovered that zeotropic compositions having a thermodynamic glide of greater than 5K and even greater than 10K can be satisfactorily used in specially designed units.

[0019] Various refrigerants are commercially available for heat pumping equipment. For chillers with a condensation pressure of less than 2 bara, low-volatility refrigerants such as R123 (bp 28°C) may be used. For chillers and intermediate temperature refrigeration, R1234ze(E) may be used, whereas for portable air conditioners, R1234yf may be preferred. Some of these refrigerants have definite disadvantages. R123 is being phased out because it has an ODP of 0.06 and a GWP of 77. R1233zd(E) (bp 18.3°C, ODP 0; GWP 1) is a potential substitute for R123, but its condensation pressure may exceed 2 bara.

[0020] R404A and R507 are widely used in refrigeration, while R410A is widely used in air conditioning and heat pumping. These are excellent refrigerants in terms of energy efficiency, non-flammability, low toxicity, and thermodynamic properties. However, because their Global Warming Potential (GWP) exceeds 2,000, they are considered environmentally unacceptable. Regulations are being introduced globally to reduce their use, which may ultimately lead to their phased phasing out. The European Union (EU) and other regions have imposed GWP limits and / or taxes to gradually reduce the utilization of R404A, R507, and R410A, along with other HFC refrigerants. The EU's F gas regulations substantially reduce the volume of refrigerants based on marketable GWP. The EU has also restricted the use of refrigerants with a GWP exceeding 150 in certain applications.

[0021] R32 has been introduced as an alternative to R410A, but it still has an unacceptably high GWP of 675 and is flammable (ASHRAE Grade A2L). R13B1 (bp -58°C) is a cryogenic refrigerant with a very high ODP of 10 on a scale where R11 has an ODP of 1 and a GWP of 6900. R22 is an excellent refrigerant, but it is being phased out due to its ODP of 0.055.

[0022] R1234yf, with a very low global warming potential, is a thermodynamically good match for R134a, with a high global warming potential, and has replaced the latter in mobile (vehicle) air conditioning systems. Nevertheless, R1234yf is flammable with an ASHRAE safety rating of A2L, and its flammability has led to industry resistance to its adoption by some vehicle manufacturers who strongly advocate for carbon dioxide, despite the operating pressure of at least 100 bar, low energy efficiency, much smaller leaks that can stop small internal combustion engines, and sensitivity to performance degradation due to high compressor starting torque.

[0023] Ammonia, hydrocarbons, and carbon dioxide are established fluids for refrigeration and air conditioning systems and have significantly lower GWPs than hydrofluorocarbons (HFCs). However, they are also toxic, flammable, or both (in the case of ammonia). Apart from significant safety risks in public places such as supermarkets, flammable hydrocarbons can only be safely used in conjunction with a secondary refrigeration circuit. This reduces energy efficiency, increases costs, and severely limits the maximum cooling duty of hydrocarbons due to their small charge volumes. CO2 must be used in a supercritical state on the high-pressure side of the system to release heat into the ambient air. Pressures often exceed 100 bara, resulting in energy penalties and significantly higher capital costs compared to conventional R404A, R507, and R410A systems.

[0024] Although HFCs are a negligible contributor to global warming compared to CO2 and methane, they are controlled by the EU’s F Gas Regulation and the Kigali Amendment to the Montreal Protocol to phase out their use, which could ultimately lead to their elimination. While the world has become accustomed to the safe and practical global use of HFCs, increasingly restrictive international HFC regulations limiting their use are causing significant uncertainty among Original Equipment Manufacturers (OEMs) regarding the selection of refrigerants for long-term use. This uncertainty is hindering the development of improved heat pumping technologies. The objective of the present invention is to address the problem of developing improved heat pumping technologies.

[0025] Since its inception in the mid-19th century, heat pumping technology has been dominated by single-component or azeotropic refrigerants, a trend that continues to this day. In the 1870s, ammonia emerged as a major industrial refrigerant, followed by carbon dioxide, sulfur dioxide, methyl chloride, and hydrocarbons. With the introduction of much safer CFCs and HCFCs in the 1930s, the refrigeration and air conditioning industries grew rapidly with the introduction of single-component refrigerants CFC-12, CFC-114, and HCFC-22, as well as azeotropic mixtures R500 and R502.

[0026] Equipment is specifically designed to optimize the performance of single-component and azeotropic refrigerants, and it was expected that newer refrigerants would comply with these engineering standards. A fundamental characteristic is that these refrigerants evaporate and condense at a constant temperature and constant pressure. This is reinforced by saturation tables, superheat tables, and pressure-enthalpy charts, which are provided by refrigerant suppliers and used by both OEMs and service technicians across the industry to optimize the operation of existing facilities. However, these limiting standards, influenced by early refrigerant development, hinder the adoption of new refrigerants that combine acceptable heat pumping performance with low risk and low environmental impact from an operational perspective. This specification discloses that refrigerants with a thermodynamic temperature glide greater than 5K, so-called "wide-glide refrigerants," or "very-wide-glide refrigerants" with a much higher glide, can overcome the problem of providing new refrigerants that combine acceptable heat pumping performance with low risk and low environmental impact from an operational perspective.

[0027] In this specification, the figures for the Global Warming Potential (GWP) refer to the Integrated Centennial Assessment (ITH) contained in the Intergovernmental Panel on Climate Change's Fourth Assessment Report.

[0028] According to the present invention, the refrigerant is composed of or essentially comprises the following:

[0029] a) carbon dioxide, a non-flammable, highly volatile component, and

[0030] b) a non-flammable, low-volatility component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1233zd(E), HFO1233zd(Z), HFO1233xf, HFO1336mzz(E), HFO1336mzz(Z), 2-bromo-3,3,3-trifluoroprop-1-ene; or mixtures thereof;

[0031] c) an intermediate volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO-1225ye(Z) and HFO1243zf or mixtures thereof; and

[0032] d) Optionally a component selected from HFC-227ea, HFC-152a, HFC-32, or a mixture thereof.

[0033] The refrigerant of the present invention can have a global warming potential of up to 400.

[0034] In this specification, percentages or other quantities are based on mass unless otherwise indicated. Quantities are selected from any given range to a total of 100%. Pressures are measured in absolute bar (bara).

[0035] The term 'hydrofluoro-olefin' can be abbreviated as 'HFO' and includes compounds containing hydrogen, fluorine, and carbon atoms, and optionally chlorine and bromine atoms.

[0036] The term "consisting of" is used herein to refer to a composition comprising only the mentioned components, disregarding any trace amounts of impurities.

[0037] The term “essentially composed” is used herein to refer to a composition composed of the listed components, wherein the addition of small amounts of any additional components that do not substantially alter the essential refrigerant properties of the composition is possible. These compositions include compositions composed of the listed components. Compositions composed of the listed components may be particularly advantageous.

[0038] The present invention relates to a very low GWP blend, which is a composition that can be used particularly in new refrigeration, air conditioning and heat pumping systems, but is not limited thereto.

[0039] The blend has an ozone depletion potential of 0, so it does not have an adverse effect on stratospheric ozone. Additionally or alternatively, the blend has a GWP of 400 or less, preferably 150 or less, and more preferably less than 10.

[0040] A method for ranking the relative flammability of refrigerants is provided by the ASHRAE 34 Committee Scale, which simply classifies refrigerants into four flammability classes.

[0041] Grade 1 No flame propagation

[0042] Grade 2L Low Flammability

[0043] Grade 2 Flammable

[0044] Grade 3 High Flammability

[0045] The blend may have an ASHRAE safety classification of A1 (non-flammable) or alternatively A2L (low flammability), which, combined with a low GWP of less than 400, preferably less than 150, most preferably less than 10, and high efficiency, provides the characteristics of a new combination. The present invention relates particularly to a refrigerant composition containing one or more hydrofluoroolefins (HFOs).

[0046] The ASHRAE scale does not further distinguish the degree of flammability within each class. However, this can be done by considering the blend's Lower Limit of Flammability (LFL). The LFL of refrigerant vapor in air at atmospheric pressure and temperature is the lower limit of the concentration range in which the vapor can ignite. If the vapor cannot ignite, there is no LFL at temperatures up to 60°C, and the ASHRAE class is Class 1.

[0047] The refrigerant of the present invention may be referred to as a wide glide or very wide glide refrigerant.

[0048] In one embodiment, the high volatile component has a vapor pressure of 1 atm at a temperature at least 10°C lower than the medium volatile component, and the medium volatile component has a vapor pressure of 1 atm at a temperature at least 10°C lower than the low volatile component.

[0049] In an embodiment, the highly volatile component may have a vapor pressure of 1 atm at a temperature in the range of -80°C to -45°C.

[0050] In one embodiment, the intermediate volatile component may have a vapor pressure of 1 atm at a temperature in the range of -35°C to -15°C.

[0051] In one embodiment, the low-volatility component may have a vapor pressure of 1 atm at a temperature in the range of 0°C to 40°C.

[0052] In an embodiment, the highest and lowest volatile components may be non-flammable and the intermediate volatile components may be flammable.

[0053] The presence of non-flammable components inhibits the flammability of flammable components or components, so the blend is non-flammable, which has the effect of raising the lower limit of flammability (LFL) of the blend. Flammable compositions having ASHRAE safety classification A2L have a higher GWP due to the presence of HFC component(s) that provide additional beneficial properties for specific applications, for example, by replacing HFCs with lower global warming blends and similar technical properties.

[0054] When a vapor or liquid leak begins, for example under conditions specified in the ASHRAE 34 standard flammability test, highly volatile non-flammable CO2 inhibits the flammability of R32, where present, and flammable HFO components, and HFC152a, where present. As the leak progresses, the concentrations of CO2 and R32, where present, decrease, while the concentrations of flammable HFO, HFC152a, and non-flammable HFO, where present, increase.

[0055] The presence of non-flammable CO2 in the initial stage of the leak and non-flammable HFO in the later stage of the leak will suppress the flammability of higher volatile HFOs, and HFC32 and HFC152a if present. Vapors and liquids with higher concentrations of non-flammable components will have a higher LFL, and thus remain ASHRAE Class 2L but have low flammability. Preferably, the ratio of non-flammable to flammable components throughout the leak is such that the vapor and liquid compositions are always non-flammable, that is, the compositions all comply with ASHRAE Safety Class A1 Class 1.

[0056] In particular, the present invention relates to a blend of CO2, a highly volatile, non-flammable component, a non-flammable HFO component of low volatility (boiling point >0°C) and very low GWP (<10), and a medium volatile component (boiling point approx. -19°C), which provides a common basis for various low-risk, eco-friendly blends capable of replacing commercially available refrigerants currently used in a wide range of heat pumping applications, including but not limited to refrigeration, vehicle and indoor air conditioning, heat pumping, and low-pressure (<2 bara) chillers. The CO2 / low volatility HFO blend contains a medium volatile component (boiling point >-53°C and <-10°C) to provide a blend having the characteristics required for specific heat pumping applications.

[0057] The inventors have discovered that fluids having an unacceptably high GWP or ODP or flammability in these refrigerant compositions can be used in currently used heat pumping applications, examples including but not limited to R13B1, R32, R410A, R404A, R507, R290 (propane), R22, R1234yf, R600 (butane), R600a (isobutane), HFO1224yd(Z), HFO1224zd(E), HFO1233zd(E), HFO1234ze(E), HFO1336mzz(Z) and HFO1336mzz(E), and some of these fluids may be components of the refrigerant composition.

[0058] In one embodiment, the refrigerant may be composed of the following components or essentially:

[0059] High volatile component, medium volatile component and low volatile component; where, the high volatile component has a vapor pressure at least 1 atm higher than the medium volatile component; and the low volatile component has a vapor pressure at least 1 atm lower than the medium volatile component.

[0060] In one embodiment, the refrigerant composition is composed of or essentially consists of the following:

[0061] Non-flammable, highly volatile component composed of carbon dioxide;

[0062] A non-flammable, low-volatility component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1233zd(E), HFO1233zd(Z), HFO1233xf, HFO1336mzz(E), HFO1336mzz(Z), 2-bromo-3,3,3-trifluoroprop-1-ene and mixtures thereof;

[0063] An intermediate volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO1225ye(Z), HFO1243zf and mixtures thereof;

[0064] One or more components optionally selected from the group consisting of HFC227ea, HFC32 and HFC152a.

[0065] In one embodiment, the refrigerant is composed of or essentially consists of the following:

[0066] a) Non-flammable, highly volatile components composed of carbon dioxide;

[0067] b) a non-flammable, low-volatility component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1233zd(E), HFO1233zd(Z), HFO1233xf, HFO1336mzz(E), HFO1336mzz(Z), 2-bromo-3,3,3-trifluoroprop-1-ene and mixtures thereof;

[0068] c) an intermediate volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO-1225ye(Z), HFO1243zf and mixtures thereof; and

[0069] d) Optionally an HFC selected from the group consisting of HFC227ea, HFC152a HFC, and mixtures thereof;

[0070] Here, the amount of the highly volatile component is in the range of 5 wt% to 85 wt%;

[0071] The amount of low-volatility components is in the range of 5 wt% to 95 wt%;

[0072] The amount of intermediate volatile components is in the range of 10 wt% to 90 wt%;

[0073] The amount of HFC32, if present, is in the range of 2 wt% to 59 wt%;

[0074] The amount of HFC227ea, if present, is in the range of 1 wt% to 12.4 wt%;

[0075] The amount of HFC152a, if present, is in the range of 2 wt% to 10 wt%, and

[0076] The amount of the ingredient is selected from the listed range as a total of 100 wt%.

[0077] The sum of the weighted GWP contribution percentages of the components cannot exceed 400.

[0078] In one embodiment, the refrigerant is composed of or essentially consists of the following:

[0079] a) Non-flammable, highly volatile components composed of carbon dioxide,

[0080] b) a non-flammable, low-volatility component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1233zd(E), HFO1233zd(Z), HFO1233xf, HFO1336mzz(E), HFO1336mzz(Z), 2-bromo-3,3,3-trifluoroprop-1-ene and mixtures thereof;

[0081] c) an intermediate volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO-1225ye(Z) and HFO1243zf or mixtures thereof; and

[0082] d) Optionally an HFC selected from the group consisting of HFC32, HFC227ea, HFC152a and mixtures thereof;

[0083] Here, the amount of the highly volatile component is in the range of 5 wt% to 60 wt%;

[0084] The amount of low-volatility components is in the range of 5 wt% to 40 wt%;

[0085] The amount of intermediate volatile components is in the range of 10 wt% to 65 wt%;

[0086] If present, the amount of HFC32 is in the range of 2 wt% to 59 wt%;

[0087] If present, the amount of HFC227ea is in the range of 1 wt% to 12.4 wt%;

[0088] If present, the amount of HFC152a is in the range of 2 wt% to 5 wt%;

[0089] Here, the amount of the ingredient is selected as a total of 100 wt% from the listed range.

[0090] The sum of the weighted GWP contribution percentages of the components cannot exceed 400.

[0091] In one embodiment, the refrigerant is composed of or essentially consists of the following:

[0092] a) Non-flammable, highly volatile components composed of CO2

[0093] b) a non-flammable, low-volatility component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1233zd(E), HFO1233zd(Z), HFO1233xf, HFO1336mzz(E), HFO1336mzz(Z), 2-bromo-3,3,3-trifluoroprop-1-ene and mixtures thereof;

[0094] c) an intermediate volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO-1225ye(Z) and HFO1243zf and mixtures thereof; and

[0095] d) Optionally, an HFC selected from HFC32, HFC152a and HFC227ea and mixtures thereof;

[0096] Here, the amount of the highly volatile component is in the range of 5 wt% to 30 wt%;

[0097] The amount of low-volatility components is in the range of 5 wt% to 40 wt%;

[0098] The amount of intermediate volatile components is in the range of 10 wt% to 65 wt%;

[0099] If present, the amount of HFC32 is in the range of 22.2 wt% to 59 wt%;

[0100] If present, the amount of HFC227ea is in the range of 4.7 wt% to 12.4 wt%;

[0101] If present, the amount of HFC152a is in the range of 2 wt% to 10 wt%;

[0102] and

[0103] Here, the amount of the ingredient is selected from the listed range as a total of 100 wt%.

[0104] The sum of the weighted GWP contribution percentages of the components may exceed 150 but not exceed 400.

[0105] In one embodiment, the refrigerant is composed of or essentially consists of the following:

[0106] a) Non-flammable, highly volatile components composed of CO2;

[0107] b) a non-flammable, low-volatility component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1233zd(E), HFO1233zd(Z), HFO1233xf, HFO1336mzz(E), HFO1336mzz(Z), 2-bromo-3,3,3-trifluoroprop-1-ene and mixtures thereof;

[0108] c) an intermediate volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO-1225ye(Z), HFO1243zf and mixtures thereof; and

[0109] d) Optionally, an HFC selected from HFC32, HFC152a and HFC227ea and mixtures thereof;

[0110] Here, the amount of highly volatile components is in the range of 5 wt% to 30 wt%;

[0111] The amount of low-volatility components is in the range of 5 wt% to 40 wt%;

[0112] The amount of intermediate volatile components is in the range of 10 wt% to 65 wt%;

[0113] If present, the amount of HFC32 is in the range of 2 wt% to 22 wt%;

[0114] If present, the amount of HFC227ea is in the range of 1 wt% to 4.7 wt%;

[0115] If present, the amount of HFC152a is in the range of 2 wt% to 5 wt%; and

[0116] The amount of the ingredient is selected from the listed range as a total of 100 wt%.

[0117] The sum of the weighted GWP contribution percentages of the components may be greater than 14 but does not exceed 150.

[0118] In embodiments of the present invention, the refrigerant is composed of or essentially comprises the following:

[0119] a) Non-flammable, highly volatile components composed of CO2

[0120] b) a non-flammable, low-volatility component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1233zd(E), HFO1233zd(Z), HFO1233xf, HFO1336mzz(E), HFO1336mzz(Z), 2-bromo-3,3,3-trifluoroprop-1-ene and mixtures thereof;

[0121] c) an intermediate volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO-1225ye(Z), HFO1243zf and mixtures thereof; and

[0122] d) HFC32;

[0123] Here, the amount of highly volatile components is in the range of 5 wt% to 30 wt%;

[0124] The amount of low-volatility components is in the range of 5 wt% to 40 wt%;

[0125] The amount of intermediate volatile components is in the range of 10 wt% to 60 wt%;

[0126] The amount of HFC32 is in the range of 2 wt% to 22 wt%;

[0127] The amount of the ingredient is selected from the listed range as a total of 100 wt%.

[0128] The sum of the weighted GWP contribution percentages of the components may be greater than 14 but does not exceed 150.

[0129] In embodiments of the present invention, the refrigerant is composed of or essentially comprises the following:

[0130] a) Non-flammable, highly volatile components composed of CO2;

[0131] b) a non-flammable, low-volatility component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1233zd(E), HFO1233zd(Z), HFO1233xf, HFO1336mzz(E), HFO1336mzz(Z), 2-bromo-3,3,3-trifluoroprop-1-ene and mixtures thereof;

[0132] c) an intermediate volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO-1225ye(Z), HFO1243zf and mixtures thereof; and

[0133] d) HFC32;

[0134] Here, the amount of highly volatile components is in the range of 6 wt% to 25 wt%;

[0135] The amount of low-volatility components is in the range of 7 wt% to 30 wt%;

[0136] The amount of intermediate volatile components is in the range of 40 wt% to 60 wt%;

[0137] The amount of HFC32 is in the range of 10 wt% to 21.5 wt%;

[0138] The amount of the ingredient is selected from the listed range as a total of 100 wt%.

[0139] The sum of the weighted GWP contribution percentages of the components may be greater than 14 but does not exceed 150.

[0140] In embodiments of the present invention, the refrigerant is composed of or essentially comprises the following:

[0141] a) Non-flammable, highly volatile components composed of CO2;

[0142] b) a non-flammable, low-volatility component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1233zd(E), HFO1233zd(Z), HFO1233xf, HFO1336mzz(E), HFO1336mzz(Z), 2-bromo-3,3,3-trifluoroprop-1-ene and mixtures thereof;

[0143] c) an intermediate volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO-1225ye(Z), HFO1243zf and mixtures thereof; and

[0144] d) HFC32;

[0145] Here, the amount of highly volatile components is in the range of 5 wt% to 15 wt%;

[0146] The amount of low-volatility components is in the range of 6 wt% to 35 wt%;

[0147] The amount of intermediate volatile components is in the range of 46 wt% to 55 wt%;

[0148] The amount of HFC32 is in the range of 15 wt% to 21.5 wt%;

[0149] The amount of the ingredient is selected from the listed range as a total of 100 wt%.

[0150] The sum of the weighted GWP contribution percentages of the components may be greater than 14 but does not exceed 150.

[0151] In one embodiment, the refrigerant is composed of or essentially consists of the following:

[0152] a) Non-flammable, highly volatile components composed of CO2;

[0153] b) a non-flammable, low-volatility component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1233zd(E), HFO1233zd(Z), HFO1233xf, HFO1336mzz(E), HFO1336mzz(Z), 2-bromo-3,3,3-trifluoroprop-1-ene and mixtures thereof;

[0154] c) an intermediate volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO-1225ye(Z), HFO1243zf and mixtures thereof; and

[0155] d) HFC227ea;

[0156] Here, the amount of highly volatile components is in the range of 5 wt% to 30 wt%;

[0157] The amount of low-volatility components is in the range of 5 wt% to 40 wt%;

[0158] The amount of intermediate volatile components is in the range of 10 wt% to 65 wt%;

[0159] The amount of HFC227ea is in the range of 2 wt% to 4.7 wt%;

[0160] The amount of the ingredient is selected from the listed range as a total of 100 wt%.

[0161] The sum of the weighted GWP contribution percentages of the components may be greater than 64 but not exceed 150.

[0162] In embodiments of the present invention, the refrigerant is composed of or essentially comprises the following:

[0163] a) Non-flammable, highly volatile component consisting of carbon dioxide;

[0164] b) a non-flammable, low-volatility component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1233zd(E), HFO1233zd(Z), HFO1233xf, HFO1336mzz(E), HFO1336mzz(Z), 2-bromo-3,3,3-trifluoroprop-1-ene and mixtures thereof;

[0165] c) an intermediate volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO-1225ye(Z), HFO1243zf and mixtures thereof; and

[0166] Here, the amount of highly volatile components is in the range of 5 wt% to 60 wt%;

[0167] The amount of low-volatility components is in the range of 5 wt% to 40 wt%;

[0168] The amount of intermediate volatile components is in the range of 10 wt% to 75 wt%;

[0169] The amount of the ingredient is selected from the listed range as a total of 100 wt%.

[0170] The sum of the weighted GWP contribution percentages of the components cannot exceed 10.

[0171] In embodiments of the present invention, the refrigerant is composed of or essentially comprises the following:

[0172] a) Non-flammable, highly volatile components composed of carbon dioxide,

[0173] b) a non-flammable, low-volatility component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1233zd(E), HFO1233zd(Z), HFO1233xf, HFO1336mzz(E), HFO1336mzz(Z), 2-bromo-3,3,3-trifluoroprop-1-ene and mixtures thereof;

[0174] c) an intermediate volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO-1225ye(Z), HFO1243zf and mixtures thereof; and

[0175] Here, the amount of highly volatile components is in the range of 10 wt% to 50 wt%;

[0176] The amount of low-volatility components is in the range of 5 wt% to 35 wt%;

[0177] The amount of intermediate volatile components is in the range of 12 wt% to 70 wt%;

[0178] The amount of the ingredient is selected from the listed range as a total of 100 wt%.

[0179] The sum of the weighted GWP contribution percentages of the components cannot exceed 10.

[0180] In embodiments of the present invention, the refrigerant is composed of or essentially comprises the following:

[0181] a) Non-flammable, highly volatile components composed of CO2;

[0182] b) a non-flammable, low-volatility component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1233zd(E), HFO1233zd(Z), HFO1233xf, HFO1336mzz(E), HFO1336mzz(Z), 2-bromo-3,3,3-trifluoroprop-1-ene and mixtures thereof;

[0183] c) an intermediate volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO-1225ye(Z), HFO1243zf and mixtures thereof;

[0184] Here, the amount of the highly volatile component is in the range of 10 wt% to 40 wt%;

[0185] The amount of intermediate volatile components is in the range of 15 wt% to 55 wt%;

[0186] The amount of low-volatility components is in the range of 7 wt% to 25 wt%; and

[0187] The amount of the ingredient is selected from the listed range as a total of 100 wt%.

[0188] The sum of the weighted GWP contribution percentages of the components cannot exceed 10.

[0189] In embodiments of the present invention, the refrigerant is composed of or essentially comprises the following:

[0190] a) Non-flammable, highly volatile components composed of CO2;

[0191] b) a non-flammable, low-volatility component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1233zd(E), HFO1233zd(Z), HFO1233xf, HFO1336mzz(E), HFO1336mzz(Z), 2-bromo-3,3,3-trifluoroprop-1-ene and mixtures thereof;

[0192] c) an intermediate volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO-1225ye(Z), HFO1243zf and mixtures thereof; and

[0193] Here, the amount of highly volatile components is in the range of 20 wt% to 40 wt%;

[0194] The amount of intermediate volatile components is in the range of 30 wt% to 55 wt%;

[0195] The amount of low-volatility components is in the range of 7 wt% to 25 wt%; and

[0196] The amount of the ingredient is selected from the listed range as a total of 100 wt%.

[0197] The sum of the weighted GWP contribution percentages of the components cannot exceed 10.

[0198] An embodiment of the present invention provides a refrigerant having a GWP of less than 400 suitable for use with a pressure-rated component of R32 and R410A, which can be used in a new split a / c unit or modified in an existing split a / c unit.

[0199] In an embodiment of the present invention, a refrigerant suitable for conversion to pure R32 in an existing split heat pump unit is composed of or essentially consists of the following:

[0200] a) Non-flammable, highly volatile components composed of CO2;

[0201] b) a non-flammable, low-volatility component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1233zd(E), HFO1233zd(Z), HFO1233xf, HFO1336mzz(E), HFO1336mzz(Z), 2-bromo-3,3,3-trifluoroprop-1-ene and mixtures thereof;

[0202] c) an intermediate volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO-1225ye(Z), HFO1243zf and mixtures thereof; and

[0203] d) HFC32;

[0204] Here, the amount of highly volatile components is in the range of 8 wt% to 19 wt%;

[0205] The amount of low-volatility components is in the range of 5 wt% to 8 wt%;

[0206] The amount of intermediate volatile components is in the range of 39 wt% to 51 wt%;

[0207] The amount of HFC32 is in the range of 35 wt% to 44 wt%;

[0208] The amount of the ingredient is selected as a total of 100wt% from the listed range, and

[0209] At 40℃, the vapor pressure at the bubble point of the blend does not exceed 30 bara.

[0210] The sum of the weighted GWP contribution percentages of the components may be greater than 14 but does not exceed 300.

[0211] Embodiments of the present invention provide a refrigerant having a GWP of less than 150 suitable for use in refrigeration applications currently provided by R404A. A preferred blend has a bubble point pressure of 30 bara or less at 35°C. A much more preferred blend has a bubble point pressure of 20 bara or less at 35°C.

[0212] In an embodiment of the present invention, a refrigerant suitable for refrigeration applications in which R404A is currently used is composed of or essentially comprises the following:

[0213] a) Non-flammable, highly volatile components composed of CO2;

[0214] b) a non-flammable, low-volatility component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1233zd(E), HFO1233zd(Z), HFO1233xf, HFO1336mzz(E), HFO1336mzz(Z), 2-bromo-3,3,3-trifluoroprop-1-ene and mixtures thereof;

[0215] c) an intermediate volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO-1225ye(Z), HFO1243zf and mixtures thereof; and

[0216] d) HFC32, HFC227ea or a mixture thereof,

[0217] Here, the amount of highly volatile components is in the range of 10 wt% to 35 wt%;

[0218] The amount of low-volatility components is in the range of 5 wt% to 20 wt%;

[0219] The amount of intermediate volatile components is in the range of 40 wt% to 80 wt%;

[0220] If present, the amount of HFC32 is in the range of 18 wt% to 22 wt%;

[0221] If present, the amount of HFC227ea is in the range of 2 wt% to 4.5 wt%;

[0222] Here, the amount of the ingredient is selected as a total of 100wt% from the listed range, and

[0223] At 35℃, the bubble point vapor pressure of the blend does not exceed 30 bara.

[0224] The sum of the weighted GWP contribution percentages of the components cannot exceed 150.

[0225] Embodiments of the present invention provide a refrigerant having a GWP of less than 150 suitable for use in refrigeration applications currently provided by R410A and HFC32. A preferred blend has a bubble point pressure of 35 bara or less at 35°C. A much more preferred blend has a bubble point pressure of 25 bara or less at 35°C.

[0226] In an embodiment of the present invention, a refrigerant suitable for refrigeration applications in which HFC32 and R410A are currently used is composed of or essentially comprises the following:

[0227] a) Non-flammable, highly volatile components composed of CO2;

[0228] b) a non-flammable, low-volatility component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1233zd(E), HFO1233zd(Z), HFO1233xf, HFO1336mzz(E), HFO1336mzz(Z), 2-bromo-3,3,3-trifluoroprop-1-ene and mixtures thereof;

[0229] c) an intermediate volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO1225ye(Z), HFO1243zf and mixtures thereof; and

[0230] d) HFC32, HFC227ea or a mixture thereof,

[0231] Here, the amount of highly volatile components is in the range of 8 wt% to 25 wt%;

[0232] The amount of low-volatility components is in the range of 5 wt% to 20 wt%;

[0233] The amount of intermediate volatile components is in the range of 35 wt% to 70 wt%;

[0234] If present, the amount of HFC32 is in the range of 18 wt% to 22 wt%.

[0235] If present, the amount of HFC227ea is in the range of 2 wt% to 5 wt%;

[0236] The amount of the ingredient is selected as a total of 100wt% from the listed range;

[0237] Here, the vapor pressure at the bubble point of the blend at 35°C does not exceed 35 bara.

[0238] The sum of the weighted GWP contribution percentages of the components cannot exceed 150.

[0239] Embodiments of the present invention provide a refrigerant having a GWP of less than 10 suitable for use in refrigeration applications currently provided by R404A. A preferred blend has a bubble point pressure of 30 bara or less at 35°C. A much more preferred blend has a bubble point pressure of 20 bara or less at 35°C.

[0240] In an embodiment of the present invention, a refrigerant suitable for refrigeration applications in which R404A is currently used is composed of or essentially comprises the following:

[0241] a) Non-flammable, highly volatile components composed of CO2;

[0242] b) a non-flammable, low-volatility component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1233zd(E), HFO1233zd(Z), HFO1233xf, HFO1336mzz(E), HFO1336mzz(Z), 2-bromo-3,3,3-trifluoroprop-1-ene and mixtures thereof;

[0243] c) an intermediate volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO-1225ye(Z), HFO1243zf and mixtures thereof; and

[0244] Here, the amount of highly volatile components is in the range of 9 wt% to 35 wt%;

[0245] The amount of low-volatility components is in the range of 5 wt% to 12 wt%;

[0246] The amount of intermediate volatile components is in the range of 39 wt% to 62 wt%;

[0247] The amount of the ingredient is selected as a total of 100wt% from the listed range, and

[0248] At 35℃, the bubble point vapor pressure of the blend does not exceed 30 bara.

[0249] The sum of the weighted GWP contribution percentages of the components may not exceed 10.

[0250] In one embodiment of the present invention, a refrigerant having a GWP of less than 10 is provided, suitable for use in refrigeration applications currently provided by R410A and R32. A desirable blend has a bubble point pressure of 45 bara or less at 35°C. A much more desirable blend has a bubble point pressure of 35 bara or less at 35°C.

[0251] In one embodiment of the present invention, R410A or R32 is provided as a refrigerant suitable for heat pumping applications currently in use, and is composed of or essentially composed of:

[0252] a) Non-flammable, highly volatile components composed of CO2;

[0253] b) a non-flammable, low-volatility component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1233zd(E), HFO1233zd(Z), HFO1233xf, HFO1336mzz(E), HFO1336mzz(Z), 2-bromo-3,3,3-trifluoroprop-1-ene and mixtures thereof;

[0254] c) an intermediate volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO-1225ye(Z), HFO1243zf and mixtures thereof; and

[0255] d) The amount of highly volatile components is in the range of 9 wt% to 30 wt%;

[0256] The amount of low-volatility components is in the range of 5 wt% to 25 wt%;

[0257] The amount of intermediate volatile components is in the range of 39 wt% to 62 wt%;

[0258] The amount of the ingredient is selected as a total of 100wt% from the listed range, and

[0259] At 35℃, the bubble point vapor pressure of the blend does not exceed 40 bara.

[0260] The sum of the weighted GWP contribution percentages of the components may not exceed 10.

[0261] For heat pumping applications where equipment footprint is an important factor, such as marine refrigeration or air conditioning, high-capacity refrigerants may be desirable but may require high-pressure components rated at so-called 100 bar. Pure CO2 operating in a supercritical cycle may provide higher capacity but may be less energy efficient than the blend provided by the present invention operating in a reverse Rankine cycle.

[0262] An embodiment of the present invention provides a refrigerant having a GWP of less than 10 suitable for use in high-capacity heat pumping applications currently provided by R404A, R410A, and R32.

[0263] In an embodiment of the present invention, a refrigerant suitable for a refrigeration application in which R404A, R410A, or R32 is currently used is composed of or essentially comprises the following:

[0264] a) Non-flammable, highly volatile components composed of CO2;

[0265] b) a non-flammable, low-volatility component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1233zd(E), HFO1233zd(Z), HFO1233xf, HFO1336mzz(E), HFO1336mzz(Z), 2-bromo-3,3,3-trifluoroprop-1-ene and mixtures thereof;

[0266] c) an intermediate volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO-1225ye(Z), HFO1243zf and mixtures thereof; and

[0267] d) The amount of highly volatile components is in the range of 70 wt% to 85 wt%;

[0268] The amount of low-volatility components is in the range of 5 wt% to 25 wt%;

[0269] The amount of intermediate volatile components is in the range of 5 wt% to 25 wt%;

[0270] The amount of the ingredient is selected from the listed range as a total of 100 wt%.

[0271] The sum of the weighted GWP contribution percentages of the components may not exceed 10.

[0272] The hydrofluoroolefin (HFO) used in the present invention comprises the following:

[0273] HFO1234yf(2,3,3,3-tetrafluoroprop-1-en);

[0274] HFO1234ze(E)(E-1,3,3,3-tetrafluoroprop-1-en);

[0275] HFO1216 (hexafluoropropene);

[0276] HFO1243zf(3,3,3-trifluoroprop-1-en);

[0277] HFO1225ye(Z)(Z-1,2,3,3,3-pentafluoroprop-1-en);

[0278] HFO1224yd(Z)(Z-1-chloro-2,3,3,3-tetrafluoropropene);

[0279] HFO1233zd(E)(E-1-chloro-3,3,3-trifluoro-prop-1-ene);

[0280] HFO1233zd(Z)(Z-1-chloro-3,3,3-trifluoro-prop-1-en);

[0281] HFO1233xf(2-chloro-3,3,3-trifluoro-prop-1-en);

[0282] 2-bromo-3,3,3-trifluoro-prop-1-en;

[0283] HFO1336mzz(Z)(Z-1,1,1,4,4,4-hexafluoro-but-1-en;

[0284] HFO1336mzz(E)(E-1,1,1,4,4,4-hexafluoro-but-1-en);

[0285] HFO1234ze(Z);

[0286] HFO1234ze(Z), which has a boiling point of 9.8°C, can be considered a low-volatility HFO, but it does not satisfy the requirement of this specification that low-volatility HFOs must be non-flammable. Nevertheless, non-flammable mixtures of HFO1234ze(Z) and other non-flammable low-volatility HFOs may be used in the compositions of the present invention.

[0287] HFO1224 can be a desirable hydrofluorocarbon.

[0288] The GWP values ​​of the listed low-volatility HFOs are very low, for example, in the range of 1 to 18.

[0289]

[0290] The equipment described in this specification includes a condenser and an evaporator. It may be of the 'DX' type, in which the refrigerant flows from one end of a 'coil' to the other. 'Coil' is a term commonly used for the length of a tube used in a heat exchanger.

[0291] In an embodiment, the heat pump device includes a circuit comprising the following:

[0292] An evaporator, compressor, condenser, expansion device, and circulating refrigerant fluid as claimed in the present invention;

[0293] A heat pump device further comprising a refrigerant fluid according to the present invention;

[0294] Here, the circuit includes one or more of the following components:

[0295] Cooling means for cooling the compressor;

[0296] An internal heat exchanger (IHX) that transfers heat from a high-pressure fluid flowing between a condenser and an expansion device to a low-pressure fluid flowing between an evaporator and a compressor.

[0297] The circuit may additionally include an accumulator for liquid refrigerant. The thermal storage unit may be located downstream of the evaporator.

[0298] The use of CO2 in refrigerant blends is disadvantageous as it can increase discharge temperature and reduce the energy efficiency of the composition. High discharge temperatures can cause excessive compressor wear, thereby reducing reliability and operating life.

[0299] Means for cooling the compressor may be provided to control the discharge temperature of the compressor and maintain it below a maximum temperature, for example, below 110°C, preferably below 100°C, and to provide at least similar energy efficiency to existing devices using CO2, R32, R410A, R404A, R507, R1234yf, R134a, R1234ze(E), R123, R1336mzz(Z), R290, R600, and R600a.

[0300] Various cooling means may be used to cool the compressor. A combination of two or more cooling means may be provided.

[0301] Subcooling can also cause compressor damage. If liquid refrigerant remains at the end of the compression just before entering the discharge line, it can cause 'liquid locking,' which can damage the exhaust valve or, in extreme cases, damage the compressor drive mechanism.

[0302] In an advantageous embodiment of the present invention, the discharge temperature and the temperature of the vapor leaving the compressor may be higher than the dew point of the refrigerant at the corresponding point in the circuit, for example, by 5°C or more, for example by 10°C or more above the dew point. This may serve to minimize the risk of liquid damaging the compressor.

[0303] The cooling means may include one or more of the following:

[0304] 1. A liquid injector adjusted to inject liquid refrigerant into a compressor;

[0305] 2. Cooling jacket in thermal contact with the compressor;

[0306] 3. A compressor having channels in the compressor head and / or body through which fluid flows to remove heat generated by the compression of the refrigerant;

[0307] 4. Injection of liquid refrigerant drawn from a location between the condenser end and the expansion device through the cooling jacket or channel of the compressor head and / or body;

[0308] 5. Injection of liquid refrigerant into the compressor discharge pipe from between the condenser end and the expansion device;

[0309] 6. Cooling coil in thermal contact with the compressor;

[0310] 7. Heat pipe in thermal contact with the compressor;

[0311] 8. A thermo-siphon in thermal contact with a compressor, and

[0312] 9. Means for injecting cold steam into a compressor.

[0313] Other cooling means may be used.

[0314] A liquid injector may be configured to inject liquid refrigerant into the suction line or the compression space of the compressor.

[0315] The wide glide, low GWP blend of the present invention may be used in various compressor types. Positive displacement type compressors may include, but are not limited to, scroll, spool, moving vane, rotary rolling piston, screw, lobe, and reciprocating compressors. Dynamic type compressors may include, but are not limited to, centrifugal and axial types. The electric motor driving the compressor may be contained within a common casing. This configuration is known as a hermetic or semi-hermetic compressor. If the motor is located outside the compressor casing, it is known as an open compressor. For the blend of the present invention, a preferred compressor design has the provision of a liquid injection that lowers the discharge temperature by injection into the suction port or the compression volume. Alternatively, cold steam may be injected into the compression volume.

[0316] The evaporator may be ‘full’. In this specification, a full evaporator means that the discharged refrigerant may be a two-phase mixture of liquid and vapor. In many modern refrigeration and air conditioning units, the refrigerant may be completely evaporated and then further superheated, for example, to 3 to 10 K, or for example, 5 K, so that the liquid does not enter the suction line and is subsequently transferred to the compressor. This is typically achieved by a thermostatic expansion valve whose opening degree changes in response to a gas bulb sensor attached to the suction line following the evaporator. The valve is adjusted so that the superheating of the vapor coming out of the compressor is set to a specific value, for example, 3 to 10 K, or for example, 5 K. When the evaporator cooling duty increases, the sensor detects superheating above 5 K and opens the valve to allow more refrigerant to enter the evaporator and restore the superheating to a preset value. A person skilled in the art knows that if superheated vapor enters the compressor, the discharge vapor may also be superheated.

[0317] However, for the wide-glide and very wide-glide refrigerants disclosed herein, superheating the refrigerant may not be practical. Consequently, the evaporator may be filled such that the exiting mixture is a two-phase liquid / vapor entering the suction line. An internal heat exchanger (IHX) may be incorporated to transfer heat from the hotter, high-pressure refrigerant returning from the condenser to the expansion unit to evaporate an additional amount of liquid in the suction line. The refrigerant exiting the IHX may be superheated so as to essentially contain no liquid phase, ensuring that no liquid enters the compressor at all. Alternatively, and advantageously, the refrigerant exiting the IHX may still contain some liquid that is allowed to enter the compressor, where the liquid rapidly evaporates as the refrigerant temperature increases by compression or by heat from the electric motor in a closed unit. This arrangement lowers the discharge temperature of the refrigerant below the temperature that would be attainable without any liquid entering the compressor. This can serve to protect the compressor from excessive wear caused by superheating.

[0318] The discharged refrigerant can be superheated to at least 5K to "dry" it, preventing the suction refrigerant from becoming too wet and damaging the compressor. Pressure and temperature sensors may be provided to the discharge line near the compressor to ensure this condition is met when the heat pumping duty changes. Sensor signals may be supplied to a microprocessor containing thermodynamic data for the refrigerant so that the microprocessor can calculate the superheating of the discharge vapor. The superheating value can control the degree of opening of the electronic expansion valve (EEV), thereby varying the flow of refrigerant entering the evaporator. If the evaporator duty decreases, the discharge superheating will decrease due to the risk of liquid remaining in the compressor at the end of compression. The EEV, controlled by the pressure and temperature sensors, reduces the refrigerant flow to increase the discharge superheating to a predetermined value. This is a method of controlling liquid injection into the compressor.

[0319] In another embodiment, a thermal expansion valve (TXV) having a gas bulb sensor in the discharge line can be used to control the flow of refrigerant entering the evaporator so that the discharge temperature does not fall below a preset value.

[0320] Operating a heat pumping device with a flooded evaporator and a very wide glide composition offers additional advantages over conventional operation where the refrigerant is completely evaporated and superheated. First, incomplete evaporation reduces the temperature glide, allowing the temperature profile to be closer to the required temperature profile for a specific application. Second, the total internal surface area of ​​the evaporator is used for evaporation, which is a more efficient heat transfer method compared to vapor superheating. Third, allowing the liquid to be discharged from the evaporator facilitates the reduction or elimination of the flammability of the entire composition by allowing the composition to include low-volatility, non-flammable HFO components to suppress the flammability of flammable components such as R32, particularly R1234yf and R1234ze(E).

[0321] It is a common understanding that xeotropic blends with wide intrinsic glide and very wide intrinsic glide will not be effective in heat pumping equipment. However, the applicant has surprisingly discovered that the wide glide or very wide glide refrigerants of the present invention can be used in heat pumping equipment. In conventional refrigeration equipment, using a typical evaporator pressure drop of about 0.3 to about 0.7 bar can induce an actual temperature glide of about 4 to about 6 K. Thus, evaporator glide is a characteristic of conventional refrigeration equipment using conventional HFC refrigerants, despite the simple modeling assumption that evaporation occurs at constant pressure and temperature. The intrinsic glide of the blend of the present invention can offset the pressure-induced glide so that the actual evaporator glide can be in the range of 1 to 4 K, that is, smaller than that of conventional equipment. Preferably, the actual glide should be nearly equal to the glide of the heat source being cooled.

[0322] In conventionally designed devices, the pressure drop between the condenser and the evaporator occurs primarily across the expansion unit. The pressure drop across the heat exchanger is minimized. However, the inventors have discovered that, surprisingly, the total pressure drop can be advantageously divided between the expansion unit and the evaporator due to wide glides and very wide glide blends. The greater the pressure drop across the evaporator, the smaller the observed glide, because the pressure-induced glide is opposite to the intrinsic refrigerant glide. However, surprisingly, energy efficiency and suction capacity are independent of the evaporator pressure drop.

[0323] The evaporator pressure drop may be varied by making one or more of the following changes to the evaporator coil. In this specification, the term "coil" refers to a length of tube that may or may not have a coiled configuration.

[0324] 1. Reduction in coil diameter.

[0325] 2. Increase in coil length.

[0326] 3. Increase in surface roughness of the inner surface of the coil.

[0327] Combining a wide glide blend with a suitable evaporator is advantageous because it allows for the selection of a glide that matches the required temperature profile of the fluid used as the heat source for the evaporator.

[0328] The above means for varying the evaporator pressure drop can also increase the heating surface area available for heat transfer, which can improve energy efficiency.

[0329] In a typical system, the refrigerant enters the condenser from the compressor in a superheated state. The vapor is then cooled until it reaches the dew point and condenses until it is completely converted into liquid at the bubble point. Heat is removed from the liquid refrigerant so that it exits the condenser supercooled by, for example, 5K. Additionally, the wide-glide cooling blend claimed herein may also undergo the same sequence in the condenser. However, it has been found that the wide-glide blend may exit the condenser advantageously at its bubble point or with a mass quality greater than zero to minimize the condenser temperature glide. The refrigerant then enters the high-pressure side of the IHX, where condensation followed by supercooling is achieved by transferring heat to a lower temperature, lower pressure flow within the suction flow.

[0330] If the actual temperature glide is too large in a particular application, a recirculating condenser design may be used, in which a portion of the liquid refrigerant from the condenser outlet is pumped back to the condenser inlet, where it is mixed with the discharge gas from the compressor and thermodynamically equilibrated. This can cool the compressor by cooling the discharge gas and removing heat from the compressor head.

[0331] Various means, including but not limited to ejector pumps or electric turbo pumps powered by the flow of discharge gas to pump liquid refrigerant, may be used.

[0332] The actual temperature glide is reduced by an amount that varies with the recirculation ratio, and the higher the ratio, the smaller the glide. This is particularly advantageous for heat pumps attached to a load where the temperature difference between the inlet and outlet temperatures of the secondary refrigerant removing heat from the condenser is smaller than the actual glide in a single-pass condenser, i.e., when the recirculation is zero.

[0333] The refrigerant blends disclosed herein may possess a combination of properties such as non-flammability and heat capacity, very low GWP, constituent materials (steel, copper-aluminum alloys, polymer sealants), and compatibility with polyol ester (POE) lubricants commonly used in the refrigeration and HVAC industries that are equivalent to or superior to these refrigerants, without the need for close matching of the thermodynamic properties of currently used commercial refrigerants. By adopting technology specifically tailored to the new blends disclosed herein, performance can be optimized for specific applications where existing refrigerants are used. Conventional design constraints associated with the use of currently used commercial refrigerants may no longer apply. Importantly, in the case of the present invention, the disadvantages of low GWP wide-glide blends, such as those perceived by traditional evaluations of low or zero-glide refrigerants, can be overcome by adopting appropriate technology.

[0334] For safety reasons, the maximum operating pressure of a given design must not be exceeded. However, when designing new equipment for the blends claimed herein, higher operating pressures may be considered if advantageous. For example, since the blend can deliver higher capacity, it requires the use of a relatively smaller compressor. The selection of new blends herein may not be constrained by the perceived need to match the generally acceptable maximum operating pressure of commercially available refrigerants.

[0335] The present invention provides several advantages. The GWP of the refrigerant composition may be less than 400, more preferably less than 150, and most preferably less than 10. Efficiency and capacity performance may be at least the same as that achieved when using units operated with currently used commercial refrigerants. Discharge temperatures of less than 100°C may be achieved. The maximum operating pressure may be similar to that of units operated with currently used commercial refrigerants. This allows for the use of existing engineering components, such as heat exchangers. The composition may provide non-flammability to ASHRAE safety classification A1. In a preferred embodiment, a single refrigerant blend may be used in refrigerant, air conditioning, and heat pumping applications.

[0336] Each blend of the subject of the present invention may be used in refrigeration equipment lubricated by oxygen-containing oils, such as polyol esters (POE) or polyalkyl glycols (PAG), or by these oils mixed with up to 50% hydrocarbon lubricants, such as mineral oil, alkylbenzene, or polyalpha-olefin. A person skilled in the art will understand that in heat pumping systems, compressor lubricants must be matched to the characteristics of the refrigerant. The higher solubility of some HFOs in POE may require higher viscosity grades of these lubricants to be used with the refrigerant blends of the present invention. This is particularly important for low-volatility HFOs, which are essential components of the blends of the present invention. Alternatively, or additionally, lubricants with a higher ratio of alkyl to ester groups may be desirable to reduce the solubility of HFOs. This can be achieved by using POE with a higher alkyl / ester ratio or by mixing separate hydrocarbon and POE lubricants.

[0337] The present invention is further explained by examples, but is not intended to be limiting.

[0338] Example 1

[0339] Comparative calculations were performed for R410A used in the typical split air conditioning system shown in FIG. 1, which includes a hermetic compressor (2) driven by an electric motor (1), a pressure casing (12) surrounding these two components, an air-cooled condenser (3), an electronic expansion valve (4), an air-heated evaporator (5), and an accumulator (6). The condenser outlet temperature of the liquid refrigerant was 40°C by 5K subcooling. The outlet temperature of the vapor from the evaporator was 12°C by 5K superheating. This unit was controlled by a microprocessor (8) that receives the temperature value for the refrigerant exiting the evaporator from a temperature sensor (7) via a data line (11) and from an indoor thermostat (13) via a data line (14). (8) controls the system to adjust the indoor temperature (4) via the signal line (10) and the speed of (1) and the compressor capacity accordingly via the signal line (9) to maintain it at the required level in response to the input data.

[0340] The key parameter values ​​that demonstrate refrigerant performance are presented in Table 1.

[0341] Example 2

[0342] A comparative calculation was performed for R404A used in a typical freezer also shown in FIG. 1, comprising a hermetic compressor (2) driven by an electric motor (1), a pressure casing (12) surrounding these two components, an air-cooled condenser (3), an electronic expansion valve (4), an air-heated evaporator (5), and an accumulator (6). The condenser outlet temperature of the liquid refrigerant was 30°C by 5K subcooling. The outlet temperature of the vapor from the evaporator was -30°C by 5K superheating. This unit was controlled by a microprocessor (8) that receives the temperature value for the refrigerant exiting the evaporator from a temperature sensor (7) via a data line (10) and from a temperature controller (13) located inside the freezer via a data line (14). (8) controls the system to adjust the freezer (4) via the signal line (10) and the speed of (1) and the compressor capacity accordingly via the signal line (9) to maintain it in the range of -18 to -23℃ in response to the input data.

[0343] The key parameter values ​​that demonstrate refrigerant performance are presented in Table 2.

[0344] Example 3

[0345] Calculations were performed for a non-flammable blend with a GWP of less than 400 in a split air conditioning system (shown in FIG. 2) comprising an accumulator (14), a hermetic compressor (1), a condenser (4), an internal heat exchanger (5) that transfers heat from a high-temperature, high-pressure refrigerant stream to a low-temperature, low-pressure refrigerant stream, an electronic expansion valve (6), and an evaporator (10). In the circuit, the refrigerant flow was controlled by pressure and temperature sensors in the discharge line immediately after the compressor. The compressor was driven by a variable-speed electric motor (12) and cooled by heat removal using a heat pipe (13). The unit was controlled by a micro-processor (9) programmed with the thermodynamic properties of the refrigerant. The micro-processor received input data from a temperature sensor (2) via data line (8) and a pressure sensor (3) via data line (7), and these sensors are located in the discharge line adjacent to the compressor. The microprocessor transmits output signals that change the motor speed via signal line (15) and change the opening degree of the expansion valve via signal line (11), thereby matching the performance of the unit to the required indoor temperature. In particular, the microprocessor avoids potentially damaging wet compression by ensuring that the superheat of the refrigerant entering the discharge line is at least 5K.

[0346] To be appropriately compared with the R410A of Example 1, the refrigerant temperature at the condenser outlet was 40°C; the evaporator inlet temperature was 7°C; the compressor isentropic efficiency was 0.7; and the electric motor efficiency was 0.9. A pressure drop was applied across the evaporator to provide an actual temperature glide of 11K.

[0347] Key parameter values ​​demonstrating the refrigerant performance of blends 1 to 12 are presented in Tables 3a and 3b.

[0348] Example 4

[0349] Calculations were performed for a non-flammable blend with a GWP of less than 400 in a refrigeration system (shown in FIG. 3) comprising an accumulator (14), a hermetic compressor (1), a condenser (4), an internal heat exchanger (5) that transfers heat from a high-temperature, high-pressure refrigerant stream to a low-temperature, low-pressure refrigerant stream, an electronic expansion valve (6), and an evaporator (10). The refrigerant flow in the circuit was controlled by pressure and temperature sensors in the discharge line immediately after the compressor. The compressor was driven by a variable-speed electric motor (12) and cooled by removing heat by pumping the liquid refrigerant into the heat exchanger (13) in contact with the compressor head using an injector pump or liquid turbopump (16) that draws the liquid refrigerant from the liquid line immediately before the expansion valve (6). The unit was controlled by a micro-processor (9) programmed with the thermodynamic properties of the refrigerant. The microprocessor receives input data from the temperature sensor (2) via the data line (8) and the pressure sensor (3) via the data line (7), and these sensors are located in the discharge line adjacent to the compressor. The microprocessor transmits output signals that change the motor speed via the signal line (15) and change the opening degree of the expansion valve via the signal line (11), so that the performance of the unit is matched to the indoor temperature required. In particular, the microprocessor avoids potentially damaging wet compression by ensuring that the superheat of the refrigerant entering the discharge line is at least 5K.

[0350] To be appropriately compared with the R404A of Example 2, the refrigerant temperature at the condenser outlet was 30°C; the evaporator inlet temperature was -35°C; the compressor isentropic efficiency was 0.7; and the electric motor efficiency was 0.9. A pressure drop was applied across the evaporator to provide an actual temperature glide of 5K.

[0351] The key parameter values ​​of blends 13 to 24 are presented in Table 4a and Table 4b.

[0352] Example 5

[0353] Calculations were performed for a non-flammable blend (25) with a GWP of 2, consisting of 5% R1224yd (Z), 69% CO2 and 26% R1234ze (E), in a split air conditioning system (Fig. 4) comprising an accumulator (13); a variable speed electric motor (4), a low-pressure first stage (1) and a high-pressure second stage (2); a condenser (5); an internal heat exchanger (IHX) (6) that transfers heat from a high-temperature, high-pressure refrigerant stream to a low-temperature, low-pressure refrigerant stream; an electronic expansion valve (7) and an evaporator (8). The refrigerant flow in the circuit was controlled by pressure and temperature sensors (10 and 11) in the suction line immediately after the IHX (6).

[0354] The gas discharged from the first compression stage passed through an external heat exchanger called an intercooler (3), where it was cooled by ambient air before entering the volume of gas inside the compressor casing surrounding the electric motor and the second-stage compressor. The gas cooled the motor and then entered the intake port of the second compression stage, where it was further compressed and then discharged to the condenser.

[0355] The unit was controlled by a microprocessor (9) programmed with the thermodynamic properties of the refrigerant. The microprocessor received input data from a temperature sensor (11), a pressure sensor (10), and a temperature sensor (16) that measured the indoor temperature. The microprocessor optimized the performance of the unit and matched the required indoor temperature by transmitting output signals that changed the motor speed via signal line (15) and changed the degree of opening of the expansion valve via signal line (12). In particular, the microprocessor ensured that the superheat of the refrigerant entering the compressor was at least 2K, preferably 5K, to avoid potentially damaging wet compression.

[0356] To be appropriately compared with the R410A of Example 1, the refrigerant temperature at the condenser outlet was 40°C; the evaporator inlet temperature was 7°C; the compressor isentropic efficiency was 0.7; and the electric motor efficiency was 0.9. A pressure drop was applied across the evaporator to provide an actual temperature glide of 11K.

[0357] The key parameter values ​​demonstrating the refrigerant performance of a blend consisting of 5% R1224yd(Z), 69% CO2, and 26% R1234ze(E) are presented in Table 5. This blend is superior to R410A for air conditioning because it combines a GWP of only 2 with a suction volume capacity of 107808 kJ / kg (R410A: 5832 kJ / kg) but has similar energy efficiency. The blend is superior to CO2 because it operates at a maximum pressure of about 60 bar (CO2: typically 130 bar), which reduces vapor back leakage from the compressor and allows for efficient condensation heat transfer to the surroundings by operating in a subcritical cycle.

[0358] Example 6

[0359] Calculations were performed for a non-flammable blend (26) with a GWP of 2, consisting of 10% R1224yd (Z), 67% CO2, and 23% R1234yf, in a split air conditioning system (shown in FIG. 4) operating under conditions similar to those of Example 5. The values ​​of the key parameters demonstrating the refrigerant performance are presented in Table 5. This blend is superior to R410A for air conditioning because it combines a GWP of only 2 with a suction volume measurement capacity of 11156 kJ / kg (R410A: 5832 kJ / kg) but has similar energy efficiency. The blend is superior to CO2 because it operates at a maximum pressure of about 60 bar (CO2: typically 130 bar), which reduces vapor backflow from the compressor and allows for efficient condensation heat transfer to the surroundings by operating in a subcritical cycle.

[0360] Example 7

[0361] Calculations were performed for a non-flammable blend (27) with a GWP of 2, consisting of 8% R1224yd (Z), 70% CO2, and 22% R1234ze (E), in an air conditioning system of an electric vehicle (Fig. 5) comprising: a single-stage hermetic compressor driven by a variable-speed electric motor (2); a condenser (3); an internal heat exchanger (IHX) (4) that transfers heat from a high-temperature, high-pressure refrigerant stream to a low-temperature, low-pressure refrigerant stream; an electronic expansion valve (5); an evaporator (6); and an accumulator (13). The refrigerant flow in the circuit included pressure and temperature sensors (7 and 8) in the suction line immediately after the IHX (4).

[0362] The unit was controlled by a microprocessor (9) programmed with the thermodynamic properties of the refrigerant. The microprocessor received input data from a temperature sensor (11) via a data line (10), a pressure sensor (10) via a data line (11), and a temperature sensor (14) via a data line (15) that measures the vehicle cabin temperature. The microprocessor transmitted output signals that changed the motor speed via a signal line (14) and changed the opening degree of the expansion valve via a signal line (12) to optimize the performance of the unit and match it to the required cabin temperature. In particular, the microprocessor ensured that the superheat of the refrigerant entering the compressor was at least 2K, preferably 5K, to avoid potentially damaging wet compression.

[0363] The key parameter values ​​demonstrating the refrigerant performance of a blend consisting of 8% R1224yd(Z), 70% CO2, and 22% R1234ze(E) are presented in Table 6. This blend (non-flammable and GWP2) is superior to both R134a (non-flammable but has a high GWP1300) and its substitute R1234yf (very low GWP2 but flammable) for vehicle air conditioning. Additionally, it is advantageous due to its much higher suction specific volume capacity than these refrigerants. This blend is superior to CO2 because it operates at a maximum pressure of about 66 bar (CO2: 130 bar), which reduces vapor backflow from the compressor and allows for efficient condensation heat transfer to the surroundings by operating in a subcritical cycle.

[0364] Table 7 also provides performance data for Blend 28 in automotive air conditioning systems.

[0365] Example 8

[0366] The performance of blends 29 to 37 (Tables 7a and 7b) containing HFC152a in the low-temperature freezing unit described in Example 4 was calculated. The results are shown in Table 7.

[0367] Example 9

[0368] The performance of blends 38 to 42, modified for HFC32 in existing split air conditioners, was calculated and compared with HFC32 (43 in Table 8b). The results are presented in Tables 8a and 8b. These blends provide acceptable energy efficiency and intake cooling capacity compared to HFC32, which has a GWP less than half that of HFC32, thereby reducing the direct impact of split air conditioners on global warming.

[0369] Example 10

[0370] The performance of blends 44 to 45 (Table 9) was calculated in a refrigeration unit similar to that described in Example 4. The results shown in Table 9 demonstrate that excellent suction cooling capacity and efficiency were obtained. The GWP of the blends is less than 150, which is the value mandated as the regulatory upper limit by some governments that enforce the phased elimination of high GWP refrigerants such as R404A and R507A.

[0371] Example 11

[0372] The performance of blends 48 to 51 (Table 10) was calculated in a split air conditioning unit similar to that described in Example 3. The results presented in Table 10 show that excellent suction cooling capacity and efficiency were obtained, which are advantageously similar to the existing refrigerants R410A and HFC32 currently used in this application. The GWP of the blends is less than 150, which is the value mandated as the regulatory upper limit by some governments that enforce the phased elimination of high GWP refrigerants such as R410A and HFC32.

[0373]

[0374]

[0375] [Table 3a]

[0376]

[0377] [Table 3a continued]

[0378]

[0379] [Table 3b]

[0380]

[0381] [Table 3b continued]

[0382]

[0383] [Table 4a]

[0384]

[0385] [Table 4a continued]

[0386]

[0387] [Table 4b]

[0388]

[0389] [Table 4b continued]

[0390]

[0391]

[0392] [Table 5 continued]

[0393]

[0394]

[0395] [Table 6 continued]

[0396]

[0397] [Table 7a]

[0398]

[0399] [Table 7a continued]

[0400]

[0401] [Table 7b]

[0402]

[0403] [Table 7b continued]

[0404]

[0405] [Table 8a]

[0406]

[0407] [Table 8a continued]

[0408]

[0409] [Table 8b]

[0410]

[0411] [Table 8b continued]

[0412]

[0413]

[0414] [Table 9 continued]

[0415]

[0416]

[0417] [Table 10 continued]

[0418]

Claims

Claim 1 As a refrigerant, a) a non-flammable, high-volatility component consisting of CO2; b) a non-flammable, low-volatility component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1336mzz(E), HFO1336mzz(Z) and mixtures thereof; c) a medium-volatility component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO1225ye(Z), HFO1243zf and mixtures thereof; and d) a refrigerant comprising, or essentially comprising, an HFC selected from the group consisting of HFC32, HFC227ea and HFC152a or a mixture thereof; wherein the amount of the high volatile component is in the range of 5 wt% to 85 wt%; the amount of the low volatile component is in the range of 5 wt% to 80 wt%; the amount of the medium volatile component is in the range of 10 wt% to 90 wt%; where present, the amount of HFC32 is in the range of 2 wt% to 59 wt%; where present, the amount of HFC227ea is in the range of 1 wt% to 12.4 wt%; where present, the amount of HFC152a is in the range of 2 wt% to 10 wt%; and the amount of the components is selected from the listed ranges to a total of 100 wt%. Claim 2 In claim 1, a) a non-flammable high-volatile component consisting of CO2; b) a non-flammable low-volatile component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1336mzz(E), HFO1336mzz(Z) and mixtures thereof; c) a medium-volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO1225ye(Z), HFO1243zf and mixtures thereof; and d) a refrigerant composed of or essentially composed of an HFC selected from the group consisting of HFC32, HFC227ea, HFC152a, and mixtures thereof; wherein the amount of the high volatile component is in the range of 5 wt% to 60 wt%; the amount of the low volatile component is in the range of 5 wt% to 40 wt%; the amount of the medium volatile component is in the range of 10 wt% to 65 wt%; where present, the amount of HFC32 is in the range of 2 wt% to 59 wt%; where present, the amount of HFC227ea is in the range of 1 wt% to 12.4 wt%; where present, the amount of HFC152a is in the range of 2 wt% to 10 wt%; and the amount of the components is selected from the listed ranges to a total of 100 wt%. Claim 3 In paragraph 2, a) a non-flammable high-volatile component consisting of CO2; b) a non-flammable low-volatile component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1336mzz(E), HFO1336mzz(Z) and mixtures thereof; c) a medium-volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO1225ye(Z), HFO1243zf and mixtures thereof; and d) a refrigerant composed of or essentially composed of an HFC selected from the group consisting of HFC32, HFC152a, HFC227ea and mixtures thereof; wherein the amount of the high volatile component is in the range of 5 wt% to 60 wt%; the amount of the low volatile component is in the range of 5 wt% to 40 wt%; the amount of the medium volatile component is in the range of 10 wt% to 65 wt%; where present, the amount of HFC32 is in the range of 2 wt% to 59 wt%; where present, the amount of HFC227ea is in the range of 4.7 wt% to 12.4 wt%; where present, the amount of HFC152a is in the range of 3 wt% to 8 wt%; and the amount of the components is selected from the listed ranges to a total of 100 wt%. Claim 4 In paragraph 2, a) a non-flammable high-volatile component consisting of CO2; b) a non-flammable low-volatile component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1336mzz(E), HFO1336mzz(Z) and mixtures thereof; c) a medium-volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO1225ye(Z), HFO1243zf and mixtures thereof; and d) a refrigerant composed of or essentially composed of an HFC selected from the group consisting of HFC32, HFC152a, HFC227ea and mixtures thereof; wherein the amount of the high volatile component is in the range of 5 wt% to 60 wt%; the amount of the low volatile component is in the range of 5 wt% to 40 wt%; the amount of the medium volatile component is in the range of 10 wt% to 65 wt%; where present, the amount of HFC32 is in the range of 2 wt% to 22 wt%; where present, the amount of HFC227ea is in the range of 1 wt% to 4.7 wt%; where present, the amount of HFC152a is in the range of 3 wt% to 5 wt%; and the amount of the components is selected from the listed ranges to a total of 100 wt%. Claim 5 In paragraph 4, a) a non-flammable high-volatile component consisting of CO2; b) a non-flammable low-volatile component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1336mzz(E), HFO1336mzz(Z) and mixtures thereof; c) a medium-volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO1225ye(Z), HFO1243zf and mixtures thereof; and d) a refrigerant comprising or essentially comprising HFC32; wherein the amount of the high volatile component is in the range of 5 wt% to 30 wt%; the amount of the low volatile component is in the range of 5 wt% to 40 wt%; the amount of the medium volatile component is in the range of 10 wt% to 60 wt%; the amount of HFC32 is in the range of 2 wt% to 22 wt%; and the amount of the components is selected from the listed ranges to a total of 100 wt%. Claim 6 In paragraph 5, a) a non-flammable high-volatile component consisting of CO2; b) a non-flammable low-volatile component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1336mzz(E), HFO1336mzz(Z) and mixtures thereof; c) a medium-volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO-1225ye(Z), HFO1243zf and mixtures thereof; and d) a refrigerant comprising or essentially comprising HFC32; wherein the amount of the high volatile component is in the range of 6 wt% to 25 wt%; the amount of the low volatile component is in the range of 7 wt% to 30 wt%; the amount of the medium volatile component is in the range of 40 wt% to 60 wt%; the amount of HFC32 is in the range of 10 wt% to 21.5 wt%; and the amount of the components is selected from the listed ranges to a total of 100 wt%. Claim 7 In claim 1, a) a non-flammable high-volatile component consisting of CO2; b) a non-flammable low-volatile component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1336mzz(E), HFO1336mzz(Z) and mixtures thereof; c) a medium-volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO-1225ye(Z), HFO1243zf and mixtures thereof; and d) a refrigerant comprising or essentially comprising HFC32; wherein the amount of the high volatile component is in the range of 5 wt% to 15 wt%; the amount of the low volatile component is in the range of 6 wt% to 35 wt%; the amount of the medium volatile component is in the range of 46 wt% to 55 wt%; and the amount of the components is selected from the listed ranges to a total of 100 wt%. Claim 8 In claim 1, a) a non-flammable high-volatile component consisting of CO2; b) a non-flammable low-volatile component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1336mzz(E), HFO1336mzz(Z) and mixtures thereof; c) a medium-volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO1225ye(Z), HFO1243zf and mixtures thereof; and d) a refrigerant comprising or essentially comprising HFC227ea; wherein the amount of the high volatile component is in the range of 5 wt% to 30 wt%; the amount of the low volatile component is in the range of 5 wt% to 80 wt%; the amount of the medium volatile component is in the range of 10 wt% to 65 wt%; the amount of HFC227ea is in the range of 2 wt% to 4.7 wt%; and the amount of the components is selected from the listed ranges to a total of 100 wt%. Claim 9 A refrigerant according to claim 1, comprising: a) a non-flammable high-volatile component consisting of CO2; b) a non-flammable low-volatile component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1336mzz(E), HFO1336mzz(Z) and mixtures thereof; and c) an intermediate-volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO1225ye(Z), HFO1243zf and mixtures thereof, wherein the amount of the high-volatile component is in the range of 5 wt% to 85 wt%; the amount of the low-volatile component is in the range of 5 wt% to 40 wt%; the amount of the intermediate-volatile component is in the range of 10 wt% to 60 wt%; and the amount of the components is selected to be a total of 100 wt% from the listed ranges. Claim 10 A refrigerant according to claim 9, comprising: a) a non-flammable high-volatile component consisting of CO2; b) a non-flammable low-volatile component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1336mzz(E), HFO1336mzz(Z) and mixtures thereof; and c) an intermediate-volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO1225ye(Z), HFO1243zf and mixtures thereof, wherein the amount of the high-volatile component is in the range of 5 wt% to 80 wt%; the amount of the low-volatile component is in the range of 2 wt% to 40 wt%; the amount of the intermediate-volatile component is in the range of 15 wt% to 60 wt%; and the amount of the components is selected from the listed ranges to a total of 100 wt%. Claim 11 A refrigerant according to claim 10, comprising: a) a non-flammable high-volatile component consisting of CO2; b) a non-flammable low-volatile component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1336mzz(E), HFO1336mzz(Z) and mixtures thereof; and c) an intermediate-volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO1225ye(Z), HFO1243zf and mixtures thereof, wherein the amount of the high-volatile component is in the range of 50 wt% to 75 wt%; the amount of the low-volatile component is in the range of 2 wt% to 25 wt%; the amount of the intermediate-volatile component is in the range of 15 wt% to 35 wt%; and the amount of the components is selected to be a total of 100 wt% from the listed ranges. Claim 12 A refrigerant according to claim 11, comprising: a) a non-flammable high-volatile component consisting of CO2; b) a non-flammable low-volatile component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1336mzz(E), HFO1336mzz(Z) and mixtures thereof; and c) an intermediate-volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO1225ye(Z), HFO1243zf and mixtures thereof, wherein the amount of the high-volatile component is in the range of 60 wt% to 75 wt%; the amount of the low-volatile component is in the range of 2 wt% to 20 wt%; the amount of the intermediate-volatile component is in the range of 15 wt% to 30 wt%; and the amount of the components is selected from the listed ranges to a total of 100 wt%. Claim 13 A refrigerant according to claim 1, comprising: a) a non-flammable high-volatile component consisting of CO2; b) a non-flammable low-volatile component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1336mzz(E), HFO1336mzz(Z) and mixtures thereof; and c) an intermediate-volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO1225ye(Z), HFO1243zf and mixtures thereof, wherein the amount of the high-volatile component is in the range of 5 wt% to 60 wt%; the amount of the low-volatile component is in the range of 5 wt% to 40 wt%; the amount of the intermediate-volatile component is in the range of 10 wt% to 75 wt%; and the amount of the components is selected to be a total of 100 wt% from the listed ranges. Claim 14 A refrigerant according to claim 1, comprising: a) a non-flammable high-volatile component consisting of CO2; b) a non-flammable low-volatile component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1336mzz(E), HFO1336mzz(Z) and mixtures thereof; and c) an intermediate-volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO1225ye(Z), HFO1243zf and mixtures thereof, wherein the amount of the high-volatile component is in the range of 10 wt% to 60 wt%; the amount of the low-volatile component is in the range of 5 wt% to 35 wt%; the amount of the intermediate-volatile component is in the range of 12 wt% to 70 wt%; and the amount of the components is selected to be a total of 100 wt% from the listed ranges. Claim 15 A refrigerant according to claim 1, comprising: a) a non-flammable high-volatile component consisting of CO2; b) a non-flammable low-volatile component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1336mzz(E), HFO1336mzz(Z) and mixtures thereof; and c) an intermediate-volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO1225ye(Z), HFO1243zf and mixtures thereof, wherein the amount of the high-volatile component is in the range of 10 wt% to 60 wt%; the amount of the intermediate-volatile component is in the range of 15 wt% to 55 wt%; the amount of the low-volatile component is in the range of 7 wt% to 35 wt%; and the amount of the components is selected to be a total of 100 wt% from the listed ranges. Claim 16 A refrigerant according to claim 15, comprising: a) a non-flammable high-volatile component consisting of CO2; b) a non-flammable low-volatile component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1336mzz(E), HFO1336mzz(Z) and mixtures thereof; and c) an intermediate-volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO-1225ye(Z), HFO1243zf and mixtures thereof, wherein the amount of the high-volatile component is in the range of 20 wt% to 40 wt%; the amount of the intermediate-volatile component is in the range of 30 wt% to 55 wt%; the amount of the low-volatile component is in the range of 7 wt% to 35 wt%; and the amount of the components is selected to be a total of 100 wt% from the listed ranges. Claim 17 In paragraph 3, a) a non-flammable high-volatile component consisting of CO2; b) a non-flammable low-volatile component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1336mzz(E), HFO1336mzz(Z) and mixtures thereof; c) a medium-volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO-1225ye(Z), HFO1243zf and mixtures thereof; and d) a refrigerant composed of or essentially composed of HFC32; wherein the amount of the high volatile component is in the range of 8 wt% to 19 wt%; the amount of the low volatile component is in the range of 5 wt% to 8 wt%; the amount of the medium volatile component is in the range of 39 wt% to 51 wt%; the amount of HFC32 is in the range of 35 wt% to 44 wt%; the amount of the components is selected from the listed ranges to a total of 100 wt%; and the bubble point vapor pressure of the refrigerant does not exceed 30 bara at 40°C, for use in new equipment and for retrofitting existing equipment. Claim 18 In paragraph 2, a) a non-flammable high-volatile component consisting of CO2; b) a non-flammable low-volatile component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1336mzz(E), HFO1336mzz(Z) and mixtures thereof; c) a medium-volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO-1225ye(Z), HFO1243zf and mixtures thereof; and d) a refrigerant composed of or essentially composed of HFC32, HFC227ea or a mixture thereof, wherein the amount of the high volatile component is in the range of 10 wt% to 35 wt%; the amount of the low volatile component is in the range of 5 wt% to 20 wt%; the amount of the medium volatile component is in the range of 40 wt% to 65 wt%; where present, the amount of HFC32 is in the range of 18 wt% to 22 wt%; where present, the amount of HFC227ea is in the range of 2 wt% to 12.4 wt%; the amount of the components is selected from the listed ranges to a total of 100 wt%; and the bubble point vapor pressure of the refrigerant does not exceed 30 bara at 35°C. Claim 19 In claim 1, a) a non-flammable high-volatile component consisting of CO2; b) a non-flammable low-volatile component selected from the group consisting of HFO1224yd(Z), HFO1224yd(E), HFO1336mzz(E), HFO1336mzz(Z) and mixtures thereof; c) an intermediate-volatile component selected from the group consisting of HFO1234yf, HFO1234ze(E), HFO1225ye(Z), HFO1243zf and mixtures thereof; d) consisting of or essentially consisting of HFC32, HFC227ea, or a mixture thereof; wherein the amount of the high-volatile component is in the range of 8 wt% to 35 wt%; the amount of the low-volatile component is in the range of 5 wt% to 20 wt%; the amount of the intermediate-volatile component is in the range of 35 wt% to 65 wt%; and, if present, the amount of HFC32 is A refrigerant in the range of 18 wt% to 22 wt%; where present, the amount of HFC227ea is in the range of 2 wt% to 12.4 wt%; the amount of the above components is selected from the listed ranges to a total of 100 wt%; and the bubble point vapor pressure of the refrigerant does not exceed 35 bara at 35°C. Claim 20 delete

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