TW202212531A - Mixed refrigerants with reduced gwp for use in ultra-low temperature refrigeration - Google Patents

Abstract

A refrigerant blend is disclosed for use in refrigeration apparatus, in particular ultra-low temperature refrigeration apparatus. The blend comprises: 10 wt% to 55 wt% of a first composition comprising at least one fluoroolefin having a normal boiling point or bubble point in the range -5 ºC to 40 ºC; 1 wt% to 40 wt% of a second composition comprising at least one refrigerant having a boiling point or bubble point in the range - 60 ºC to -15 ºC; 0.5 wt% to 35 wt% of a third composition comprising at least one refrigerant having a boiling point or bubble point in the range - 110 ºC to -70 ºC; 10 wt% to 50 wt% of a fourth composition comprising at least one refrigerant having a boiling point or bubble point in the range - 170 ºC to -110 ºC; and 0.5 wt% to 20 wt% of a fifth composition comprising at least one refrigerant having a boiling point or bubble point in the range - 250 ºC to -180 ºC. Also disclosed is the use of the blend in refrigeration apparatus and apparatus containing the blend.

Description

Mixed refrigerants with low global warming potential (GWP) for ultra-low temperature freezing

The field of the invention pertains to refrigerant blends for refrigeration equipment, the use of such refrigerant blends in refrigeration equipment, particularly ultra-low temperature refrigeration equipment, and refrigeration equipment containing such refrigerant blends.

Conventional refrigerants for cryogenic and very low temperature freezing have been problematic. To reduce the problems associated with ozone depletion, chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) refrigerants are subject to increasingly stringent regulations. Hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs) are regulated as fluorinated gases (eg according to EC517/2014), which can remain in the atmosphere for hundreds of years and contribute to the global greenhouse effect. The global warming potential of refrigerants can be quantified by the Global Warming Potential (GWP), which is calculated as the 100-year warming potential of one kilogram of greenhouse gases relative to one kilogram of CO ₂ . HFC and PFC refrigerants, such as HFC-23 (fluoroform), HFC-125 (pentafluoroethane), HFC-236fa (1,1,1,3,3,3-hexafluoropropane), HFC-245fa (1 , 1,1,3,3-pentafluoropropane) and PFC-14 (tetrafluoromethane) had high GWP values of 14800, 3500, 9810, 1030 and 7300, respectively.

The wider refrigeration industry has attempted to use refrigerants with low global warming potential and zero ozone depletion potential (ODP) to provide an environmentally friendly alternative to HFCs and PFCs. This is more difficult in ultra-low temperature refrigeration systems, which have so far been less regulated due to much lower usage. However, even in ultra-low temperature freezing in the future, it will be beneficial to use more and more low GWP and zero ODP refrigerants.

WO-A-01/40397 (and US-B-6 481 223) discloses a refrigerant blend which is free of R-22 (chlorodifluoromethane, _CHClF2 ) and can be used to provide the same as previous blends Refrigeration performance without changing the compressor, compressor oil, refrigerant liquid-vapor phase separator or heat exchanger configuration.

EP-A-2 867 596 discloses refrigeration systems and in particular improvements to cascade refrigeration systems and improved refrigerants for such systems.

WO-A-02/01120 (and US-B-6 502 410) discloses a non-flammable, non-toxic, chlorine-free refrigerant mixture for very low temperature refrigeration systems.

The ultra-low temperature refrigeration system includes an automatic cascade system in which a multi-stage cascade cooling effect occurs simultaneously by virtue of the vapor/liquid separation and adiabatic expansion of the refrigerant. Physical and thermodynamic characteristics, along with a series of countercurrent heat exchangers and a suitable refrigerant mixture, allow the system to reach temperatures as low as -90°C to -160°C. US-B-7 059 144 discloses an ultra-low temperature freezing system in which the freezing of the refrigerant is prevented.

Refrigerants or refrigerant blends, especially those used in cryogenic refrigeration, should have good oil miscibility, good energy efficiency, and should not be used in the coldest part of the system, in addition to having low GWP and low or zero ODP. Partially frozen.

An object of the present invention is to solve the problems of the prior art and to provide an improved refrigerant blend.

Accordingly, the present invention provides, in a first aspect, a refrigerant blend for refrigeration equipment, the refrigerant blend comprising: a. 10 wt % to 55 wt % (optionally 15 wt % to 45 wt %) of a first composition comprising a At least one fluoroolefin with a normal boiling point or a bubble point in the range of ℃ to 34℃); b. 1 wt% to 40 wt% (optionally 5 wt% to 30 wt%) of a second composition comprising a second composition having a temperature in the range of -60°C to -15°C (optionally -19°C to -52°C) At least one refrigerant with a boiling point or bubble point in it; c. 0.5 wt% to 35 wt% (optionally 1 wt% to 25 wt%) of a third composition comprising a third composition having a temperature in the range of -110°C to -70°C (optionally -104°C to -82°C) At least one refrigerant with a boiling point or bubble point in it; d. 10 wt% to 50 wt% (optionally 15 wt% to 40 wt%) of a fourth composition comprising a fourth composition having a temperature in the range of -170°C to -110°C (optionally -128°C to -161°C) at least one refrigerant with a boiling or bubble point in it; and e. 0.5 wt% to 20 wt% (optionally 1 wt% to 15 wt%) of a fifth composition comprising a At least one refrigerant with a boiling point or bubble point inside.

When the second composition includes a non-azeotrope, the bubble point may be in the range -60°C to -15°C, optionally -19°C to -55°C, optionally -21°C to -52°C.

When the second composition includes an azeotrope, the boiling point may range from -60°C to -15°C; optionally -15°C to -50°C, optionally -16°C to -40°C, optionally -17°C to -32°C.

Although, if necessary, some relatively high GWP refrigerants such as R-23 and R-14 can be used, to further reduce GWP, one or more hydrocarbons such as ethane or ethylene or methane can be used to Substitute R-23 and/or R-14. Although hydrocarbons may be flammable, the composition of the blend with hydrocarbons can be adjusted to reduce or avoid the flammability of the overall blend.

Thus, the refrigerant blend contains no intentionally added HFC-32 and/or HFC-365mfc, as appropriate. In some embodiments, the refrigerant blend may be free of intentionally added R-23.

In a second aspect, the present invention provides the use of a refrigerant blend as discussed herein in a refrigeration apparatus, the refrigeration apparatus including in a refrigeration system having a liquid/vapor phase separator, a throttling device, and/or A compressor cycle in an automatic refrigeration cascade of a Klimenko type system. This application is preferably achieved below -90°C, optionally lower than -100°C, optionally lower than -110°C, optionally lower than -115°C, optionally lower than -120°C, optionally lower than - A freezing temperature of 130°C, optionally below -132°C and optionally within the range of -90°C to -196°C.

In a third aspect, the present invention provides refrigeration equipment comprising a refrigerant blend as discussed herein, wherein the refrigeration equipment is included in a refrigeration system having a liquid/vapor phase separator, a throttling device, and/or A compressor cycle in an automatic refrigeration cascade of a Clemanco type system.

The refrigerant blends, uses and devices of aspects of the present invention have been used in many cryogenic and ultra-low temperature fields. For example, the cooling object may be: a metal element in a vacuum chamber, which freezes and traps gases (especially undesired gases, such as water vapor, for example); a heat exchanger, which self-contains a liquid, a gas, A primary fluid flow of at least one of a condensed gas and a condensed gas mixture removes heat; optionally has internal refrigerant flow channels and cools a silicon wafer, a glass sheet, a plastic sheet, and a wafer with or without a magnetic coating a metal element of at least one of an aluminum tray; and a biocooler for cooling and/or storing biological tissue.

As discussed above, refrigerant blends according to the present invention are very advantageous. Suitably, in one aspect, there is provided a refrigerant blend for use in refrigeration equipment, the refrigerant blend comprising: a. 29 wt% to 42 wt% of a first composition comprising having a normal boiling point in the range -5°C to 40°C (optionally 0°C to 38°C, optionally 5°C to 34°C) or at least one fluoroolefin with a bubble point, including R-1224 or R-1233 as appropriate; b. 10 wt% to 15 wt% of a second composition comprising at least a A fluoroolefin, optionally including HFO or HCFO, optionally including a non-azeotrope or azeotrope (with HFO or HCFO component as appropriate), and more optionally R-449; c. 4 wt% to 23 wt% of a third composition comprising at least one having a boiling or bubble point in the range -110°C to -70°C (optionally -104°C to -82°C) Refrigerants, including R-23 (trifluoromethane), R-170 (ethane) or ethylene as appropriate; d. One of 27 wt% to 38 wt% or 29 wt% to 38 wt% of a fourth composition comprising one of having in the range -170°C to -110°C (as appropriate -128°C to -161°C) At least one refrigerant with boiling point or bubble point, including R14 (tetrafluoromethane) or methane as appropriate; and e. 5 wt% to 10 wt% of a fifth composition comprising at least one having a boiling or bubble point in the range -250°C to -180°C (optionally -186°C to -246°C) Refrigerants, including argon or nitrogen or neon as appropriate.

Further specific and preferred aspects are set forth in the accompanying independent and dependent claims. The features of the dependent technical solution can be combined with the features of the independent technical solution when appropriate, and the combinations are different from those explicitly stated in the scope of the patent application for the invention.

Where an equipment feature is described as being operable to provide a function, it will be understood that this includes one that provides that function or is adapted or configured to provide that function.

In this specification, mass% and wt% are used interchangeably and refer to the weight percent of components in the refrigerant blend, unless the context requires otherwise.

In this specification, olefin refers to an unsaturated compound containing at least one carbon-carbon double bond. Fluoroolefin refers to an olefin containing at least one fluorine. Hydrofluoroolefins refer to olefins having at least one hydrogen and at least one fluorine. Hydrochlorofluoroolefins refer to olefins having at least one hydrogen, at least one chlorine and at least one fluorine.

In this specification, the boiling point or bubble point refers to the boiling point or bubble point at atmospheric pressure.

In this specification, a non-azeotropic mixture refers to a mixture of components having different boiling points. Individual substances in a mixture do not evaporate or condense at the same temperature as one substance, but undergo a phase change over a range of temperatures. The temperature range may be the temperature difference between the bubble point and the dew point of the non-azeotropic mixture.

Before discussing the embodiments in more detail, an overview will first be provided.

An automatic cascade refrigeration system is a self-contained refrigeration system in which a multi-stage cascade cooling effect is simultaneously generated by means of the vapor/liquid separation and adiabatic expansion of the refrigerant. Physical and thermodynamic characteristics, along with a series of countercurrent heat exchangers and a suitable refrigerant mixture, allow the system to reach temperatures as low as -90°C to -196°C or -90°C to -160°C.

FIG. 1 illustrates an exemplary automated tandem freezer 20 . A refrigerant (eg, a refrigerant blend) is compressed in compressor 22 . The compressed refrigerant is passed through an oil separator 24 to remove lubricant from the compressed refrigerant stream. Oil separated by oil separator 24 may be returned to compressor 22; the return oil is from the lower portion of oil separator 24, as shown. The use of oil separator 24 is optional and depends on the amount of oil injected into the discharge stream and the tolerance of the refrigeration program to the oil.

The compressed refrigerant passes from the oil separator 24 through a line to the condenser 26 where the compressed refrigerant is cooled and may be partially or fully condensed. A cooling medium 28 flowing through the condenser 26 may be used to condense the compressed refrigerant.

The condensed refrigerant is transferred from condenser 26 to one or more heat exchangers 30 , phase separator 32 and expansion device 34 . An outlet leads to evaporator 36, which cools a process or object by absorbing heat from the process or object. The heated refrigerant is returned to the refrigeration unit. In a tandem configuration, the evaporator 36 may be used to cool the refrigerant in the next cooler stage.

The refrigeration part of the equipment is an automatic refrigeration cascade system and includes a first heat exchanger 30a, a first phase separator 32a, a second heat exchanger 30b, a second phase separator 32b, a third The heat exchanger 30c, a fourth heat exchanger 30d, and a first expansion device 34a, a second expansion device 34b, a third expansion device 34c, and a fourth expansion device 34d. The phase separators 32a, 32b have a vapor outlet at the top and a liquid outlet at the bottom, as shown. Heat exchanger 30 provides heat transfer from the high pressure refrigerant to the low pressure refrigerant. The expansion device 34 throttles the high pressure refrigerant to a low pressure and produces a freezing effect as a result of the throttling process.

The automatic tandem freezer 20 in FIG. 1 can have three modes of operation: standby, cooling and defrosting. When both solenoid valves 38a, 38b are closed, the apparatus is in standby mode, which means that no refrigerant admixture enters the evaporator 36. When the solenoid valve at bottom 38b is open and the solenoid valve at top 38a remains closed, the device is in cooling mode. In cooling mode, the cold refrigerant blend enters the evaporator 36 and cools it within minutes. When the solenoid valve 38b at the bottom remains closed and the upper valve 38a is open, the device is in defrost mode. The defrost mode is typically used to bypass hot gas at the discharge side of the compressor 22 into the evaporator 36 and heat it. The temperature of the various parts of the apparatus can be measured by thermocouples (TC) as depicted in Figure 1, in particular the return TC 44, the coldest TC 42, the feed TC 46 and the discharge TC 40.

There are several important considerations for a successful automated inline refrigeration system: 1. The refrigerant blend should have good physical and thermodynamic properties such as density, viscosity, thermal conductivity, latent heat and heat capacity to provide good heat transfer performance in heat exchangers. 2. The oil in the system should provide good lubricity and stability and be miscible with the refrigerant blend so that the oil can be returned to the compressor without staying in the system. 3. The blend should not freeze in the coldest part of the system. 4. The flammability of the refrigerant blend should be controlled.

Embodiments of the present invention address these considerations and use one or more hydrofluoroolefins (HFOs) or hydrochlorofluoroolefins (HCFOs) as components in the refrigerant blend. Examples of HFO and HCFO that can be used are described in Table 1 below. These refrigerants have zero ozone depletion potential (ODP) and low GWP and thus offer a greener alternative to CFCs, HCFCs and HFCs. Refrigerant number Chemical Name chemical formula security group GWP Normal Boiling Point ( ^o C ) 1233zd(E) trans-1-chloro-3,3,3-trifluoro-1-propene CF ₃ CH=CHCl A1 4 18.1 1234yf 2,3,3,3-Tetrafluoro-1-propene CF ₃ CF=CH ₂ A2L 4 -29.4 1234ze(E) trans-1,3,3,3-tetrafluoro-1-propene CF ₃ CH=CFH A2L 7 -19.0 1336mzz(Z) cis-1,1,1,4,4,4-hexafluoro-2-butene CF ₃ CHCHCF ₃ A1 9 33.4 1224yd(Z) 2,3,3,3-Tetrafluoro-1-chloroprop-1ene CF ₃ -CF=CHCl A1 1 14 Table 1.

Examples of refrigerant azeotropes with HFO or HCFO components that can be used are described in Table 2 below. Refrigerant number Composition (Mass % ) security group GWP Bubble point ( ^o C ) 444A R-32/152a/1234ze(E) (12.0/5.0/83.0) A2L 92 -34.3 444B R-32/152a/1234ze(E) (41.5/10.0/48.5) A2L 350 -44.6 445A R-744/134a/1234ze(E) (6.0/9.0/85.0) A2L 130 -50.3 446A R-32/1234ze(E)/600 (68.0/29.0/3.0) A2L 461 -49.4 447A R-32/125/1234ze(E) (68.0/3.5/28.5) A2L 583 -49.3 447B R-32/125/1234ze(E) (68.0/8.0/24.0) A2L 714 -50.1 448A R-32/125/1234yf/134a/1234ze(E) (26.0/26.0/20.0/21.0/7.0) A1 1,273 -45.9 449A R-32/125/1234yf/134a (24.3/24.7/25.3/25.7) A1 1,397 -46.0 449B R-32/125/1234yf/134a (25.2/24.3/23.2/27.3) A1 1,412 -46.1 449C R-32/125/1234yf/134a (20.0/20.0/31.0/29.0) A1 1,146 -44.6 450A R-134a/1234ze(E) (42.0/58.0) A1 600 -23.4 451A R-1234yf/134a (89.8/10.2) A2L 149 -30.8 451B R-1234yf/134a (88.8/11.2) A2L 164 -31.0 452A R-32/125/1234yf (11.0/59.0/30.0) A1 1,945 -47.0 452B R-32/125/1234yf (67.0/7.0/26.0) A2L 676 -51.0 452C R-32/125/1234yf (12.5/61.0/26.5) A1 2,220 -47.5 454A R-32/1234yf (35.0/65.0) A2L 238 -48.4 454B R-32/1234yf (68.9/31.1) A2L 466 -50.9 454C R-32/1234yf (21.5/78.5) A2L 148 -46.0 455A R-744/32/1234yf (3.0/21.5/75.5) A2L 145 -51.6 456A R-32/134a/1234ze(E) (6.0/45.0/49.0) A1 687 -30.4 457A R-32/1234yf/152a (18.0/70.0/12.0) A2L 139 -42.7 459A R-32/1234yf/1234ze(E) (68.0/26.0/6.0) A2L 461 -50.3 459B R-32/1234yf/1234ze(E) (21.0/69.0/10.0) A2L 145 -44.0 460A R-32/125/134a/1234ze(E) (12.0/52.0/14.0/22.0) A1 2,103 -44.6 460B R-32/125/134a/1234ze(E) (28.0/25.0/20.0/27.0) A1 1,352 -45.2 Table 2.

Examples of refrigerant azeotropes with HFO or HCFO components that may be used are described in Table 3 below. Refrigerant number Composition (Mass % ) security group GWP Normal Boiling Point ( ^o C ) 513A R-1234yf/134a (56.0/44.0) A1 573 -29.2 513B R-1234yf/134a (58.5/41.5) A1 596 -29.2 515A R-1234ze(E)/227ea (88.0/12.0) A1 939 -18.9 516A R-1234yf/134a/152a (77.5/8.5/14) A2L 131 -29.4 table 3

An embodiment of the present invention may be a refrigerant blend comprising five compositions or groups of components blended together at a specified weight % of the blend. The groups/compositions have different boiling or bubble points.

Group 1 is present in an amount of one of about 10 wt% to 55 wt% or 15 wt% to 45 wt% of the refrigerant blend. Examples of fluoroolefins in Group 1 are described in Table 4 below. Refrigerant number Chemical Name security group GWP Normal Boiling Point ( ^o C ) 1233zd(E) trans-1-chloro-3,3,3-trifluoro-1-propene A1 4 18.1 1336mzz(Z) cis-1,1,1,4,4,4-hexafluoro-2-butene A1 9 33.4 1224yd(Z) 2,3,3,3,-Tetrafluoro-1-chloropropionic acid-1-ene A1 1 14 1345zfc 3,3,4,4,4-Pentafluorobutane-1-ene 0.09 5 1233xf 2-Chloro-3,3,3-trifluoropropene 1 15 Table 4

Group 2 is present in an amount of one of about 1 wt% to 40 wt% or 5 wt% to 30 wt% of the refrigerant blend. Examples of refrigerants in group 2 are described in Tables 5 (compounds), 6 (non-azeotropes) and 7 (azeotropes). Refrigerant number Chemical Name security group GWP Normal Boiling Point ( ^o C ) 1234yf 2,3,3,3-Tetrafluoro-1-propene A2L 4 -29.4 1234ze(E) trans-1,3,3,3-tetrafluoro-1-propene A2L 7 -19.0 32 Difluoromethane A2L 675 -52 134a 1,1,1,2-Tetrafluoroethane A1 1,430 -26.2 table 5 Refrigerant number Composition (Mass % ) security group GWP Bubble point ( ^o C ) 444A R-32/152a/1234ze(E) (12.0/5.0/83.0) A2L 92 -34.3 444B R-32/152a/1234ze(E) (41.5/10.0/48.5) A2L 350 -44.6 445A R-744/134a/1234ze(E) (6.0/9.0/85.0) A2L 130 -50.3 446A R-32/1234ze(E)/600 (68.0/29.0/3.0) A2L 461 -49.4 447A R-32/125/1234ze(E) (68.0/3.5/28.5) A2L 583 -49.3 447B R-32/125/1234ze(E) (68.0/8.0/24.0) A2L 714 -50.1 448A R-32/125/1234yf/134a/1234ze(E) (26.0/26.0/20.0/21.0/7.0) A1 1,273 -45.9 449A R-32/125/1234yf/134a (24.3/24.7/25.3/25.7) A1 1,397 -46.0 449B R-32/125/1234yf/134a (25.2/24.3/23.2/27.3) A1 1,412 -46.1 449C R-32/125/1234yf/134a (20.0/20.0/31.0/29.0) A1 1,146 -44.6 450A R-134a/1234ze(E) (42.0/58.0) A1 600 -23.4 451A R-1234yf/134a (89.8/10.2) A2L 149 -30.8 451B R-1234yf/134a (88.8/11.2) A2L 164 -31.0 452A R-32/125/1234yf (11.0/59.0/30.0) A1 1,945 -47.0 452B R-32/125/1234yf (67.0/7.0/26.0) A2L 676 -51.0 452C R-32/125/1234yf (12.5/61.0/26.5) A1 2,220 -47.5 453A R-32/125/134a/227ea/600/601a (20.0/20.0/53.8/5.0/0.6/0.6) A1 1,765 -42.2 454A R-32/1234yf (35.0/65.0) A2L 238 -48.4 454B R-32/1234yf (68.9/31.1) A2L 466 -50.9 454C R-32/1234yf (21.5/78.5) A2L 148 -46.0 455A R-744/32/1234yf (3.0/21.5/75.5) A2L 145 -51.6 456A R-32/134a/1234ze(E) (6.0/45.0/49.0) A1 687 -30.4 457A R-32/1234yf/152a (18.0/70.0/12.0) A2L 139 -42.7 458A R-32/125/134a/227ea/236fa (20.5/4.0/61.4/13.5/0.6) A1 1,650 -39.8 459A R-32/1234yf/1234ze(E) (68.0/26.0/6.0) A2L 461 -50.3 459B R-32/1234yf/1234ze(E) (21.0/69.0/10.0) A2L 145 -44.0 460A R-32/125/134a/1234ze(E) (12.0/52.0/14.0/22.0) A1 2,103 -44.6 460B R-32/125/134a/1234ze(E) (28.0/25.0/20.0/27.0) A1 1,352 -45.2 461A R-125/143a/134a/227ea/600a (55.0/5.0/32.0/5.0/3.0) A1 2,103 -42.0 462A R-32/125/143a/134a/600 (9.0/42.0/2.0/44.0/3.0) A2 2,249 -42.6 Table 6 Refrigerant number Composition (Mass % ) security group GWP Normal Boiling Point ( ^o C ) 513A R-1234yf/134a (56.0/44.0) A1 573 -29.2 513B R-1234yf/134a (58.5/41.5) A1 596 -29.2 515A R-1234ze(E)/227ea (88.0/12.0) A1 939 -18.9 516A R-1234yf/134a/152a (77.5/8.5/14) A2L 131 -29.4 Table 7

Group 3 is present in an amount of one of about 0.5 wt% to 35 wt% or 1 wt% to 25 wt% of the refrigerant blend. Examples of refrigerants in Group 3 are described in Table 8 below. Refrigerant number Chemical name (wt % ) chemical formula security group GWP Normal Boiling / Bubbling Point ( ^o C ) twenty three trifluoromethane CHF ₃ A1 14,800 -82 469A R-744/32/125 (35/32.5/32.5) 35% CO ₂ + 32.5% CH ₂ F ₂ +32.5% C ₂ HF ₅ A1 1,357 -78.5 508B R-23/116 (46/54) 46% CHF ₃ + 54% C ₂ F ₆ A1 13,396 −88.3/-45.6 170 Ethane CH ₃ CH ₃ A3 6 -89 1150 Ethylene CH ₂ =CH ₂ A3 4 -104 Table 8

Although ethane and ethylene (and methane, which can also be used in the blend) are potentially flammable, the composition of the HCs in the blend can be adjusted to control, reduce or avoid the flammability of the overall blend.

Group 4 is present in an amount of one of about 10 wt% to 50 wt% or 15 wt% to 40 wt% of the refrigerant blend. Examples of refrigerants in Group 4 are described in Table 9 below. Refrigerant number Chemical Name chemical formula security group GWP Normal Boiling / Bubbling Point ( ^o C ) 14 tetrafluoromethane _CF4 A1 7,390 -128 50 Methane CH ₄ A3 25 -161 472A R-744/32/134a (69/12/19) 69% CO ₂ + 12% CH ₂ F ₂ +19% C ₂ H ₂ F ₄ A1 353 -119.7 784 krypton Kr A1 0 -153 Table 9

Group 5 is present in an amount of one of about 0.5 wt% to 20 wt% or 1 wt% to 15 wt% of the refrigerant blend. Examples of refrigerants in Group 5 are described in Table 10 below. Refrigerant number Chemical Name chemical formula security group GWP Normal Boiling Point ( ^o C ) 740 Argon Ar A1 0 -186 728 nitrogen N ₂ A1 0 -196 720 neon Ne A1 0 -246 Table 10 Examples

In the examples described in Table 11 below, refrigerant blends with compositions 1 to 6 were prepared (in Example 4, composition 4 had two components: R14 and methane). The GWP values of the blends are indicated and they are significantly improved. The current EU threshold for stationary refrigeration equipment is 2,500, and Examples 3 and 4 improve that value. Example refrigerant blend Composition (wt % ) Blend GWP Example 1 1224yd(Z)/449C/23/14/Argon 29/12/23/31/5 5,822 Example 2 1224yd(Z)/449C/23/14/Argon 36/10/9/38/7 4,255 Example 3 1224yd(Z)/449C/ethylene/14/argon 40/14/5/31/10 2,451 Example 4 1224yd(Z)/449C/ethylene/14/methane/argon 42/15/4/27/2/10 2,168 Example 5 R-1233zd/R-449A/R-23/R-14/Argon 29/12/23/31/5 5,839 Example 6 R-1233zd/R-449A/R-170/R-14/Argon 35/10/11/37/6 2,864 Table 11

The refrigerant blends of Examples 5 and 6 were charged separately into a Polycold MaxCool Cryochiller. Start-up (standby mode) and cool-down (cooling mode) tests were performed under normal operating conditions (20 ^o C to 25 ^o C room temperature and cooling water temperature). The test results are shown in Figures 2 and 3. The MaxCool Cryochiller performance of this blend has passed all temperature and pressure specifications.

In FIG. 2 , 6 indicates the coldest temperature profile of Example 5; 7 indicates the coldest temperature profile of Example 6; 8 indicates the discharge temperature profile of Example 5 and 9 indicates the discharge temperature profile of Example 6.

3, 12 indicates the feed temperature profile of Example 5; 14 indicates the reflux temperature profile of Example 5; 16 indicates the coldest temperature profile of Example 5; and 18 indicates the discharge temperature profile of Example 5.

Although illustrative embodiments of the invention have been disclosed in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to the precise embodiments and Various changes and modifications can be effected therein by those skilled in the art within the scope of the invention.

6: Example 5 of the coldest temperature curve 7: Example 6 of the coldest temperature curve 8: Example 5 of the discharge temperature curve 9: Example 6 of the discharge temperature curve 12: Example 5 of feed temperature curve 14: Reflow temperature curve example 5 16: Example 5 of the coldest temperature curve 18: Example 5 of the discharge temperature curve 20: Refrigeration equipment 22: Compressor 24: Oil separator 26: Condenser 28: Cooling medium 30a: first heat exchanger 30b: Second heat exchanger 30c: Third heat exchanger 30d: Fourth heat exchanger 32a: first phase separator 32b: Second Phase Separator 34a: First expansion device 34b: Second expansion device 34c: Third expansion device 34d: Fourth expansion device 36: Evaporator 38a: Upper solenoid valve 38b: Lower solenoid valve 40: Discharge Thermocouple 42: coldest thermocouple 44: Return Thermocouple 46: Feed Thermocouple

Embodiments of the present invention will now be further described with reference to the accompanying drawings, in which:

Figure 1 shows an automated in-line refrigeration plant in which the refrigerant blend of the present invention can be used;

Figure 2 shows the test results using the blends of Example 5 and Example 6 in standby mode;

Figure 3 shows the results of testing using the blend of Example 5 in cooling mode.

20: Automatic cascade refrigeration equipment

22: Compressor

24: Oil separator

26: Condenser

28: Cooling medium

30a: first heat exchanger

30b: Second heat exchanger

30c: Third heat exchanger

30d: Fourth heat exchanger

32a: first phase separator

32b: Second Phase Separator

34a: First expansion device

34b: Second expansion device

34c: Third expansion device

34d: Fourth expansion device

36: Evaporator

38a: Solenoid valve/upper valve

38b: Solenoid valve

40: Emission Thermocouple (TC)

42: coldest thermocouple (TC)

44: Return Thermocouple (TC)

46: Feed Thermocouple (TC)

Claims (23)

A refrigerant blend for use in refrigeration equipment, the refrigerant blend comprising: a. 10 wt% to 55 wt% of a first composition comprising at least one fluoroolefin having a normal boiling or bubble point in the range -5°C to 40°C; b. 1 wt% to 40 wt% of a second composition comprising at least one refrigerant having a boiling or bubble point in the range -60°C to -15°C; c. 0.5 wt% to 35 wt% of a third composition comprising at least one refrigerant having a boiling or bubble point in the range -110°C to -70°C; d. 10 wt% to 50 wt% of a fourth composition comprising at least one refrigerant having a boiling or bubble point in the range -170°C to -110°C; and e. 0.5 wt% to 20 wt% of a fifth composition comprising at least one refrigerant having a boiling or bubble point in the range -250°C to -180°C. The refrigerant blend of claim 1, wherein the at least one fluoroolefin comprises an olefin having at least one fluoro substituent. The refrigerant blend of claim 1 or claim 2, wherein the at least one fluoroolefin comprises a hydrofluoroolefin (HFO) or a hydrochlorofluoroolefin (HCFO). The refrigerant blend of claim 1 or claim 2, wherein the at least one fluoroolefin comprises fluoropropene or fluorobutene. The refrigerant blend of claim 4, wherein the fluoroolefin comprises the chemical formula CH( _{2-b - c ) ClbFc} =CH( _1-ef ) _{CleFfCH ( 3-hi ) ClhFi} A compound, wherein b, c are independently selected from 0, 1 or 2; e, f are independently selected from 0 or 1; and h, i are independently selected from 0, 1, 2, 3. The refrigerant blend of claim 4, wherein the fluoroolefin comprises the formula CH _{(2-bc) ClbFc =} CH _{(1-ef) CleFfCH (2-hi ) ClhFiCH ( 3 -km)} Cl _k F _m or CH _(3-hi) Cl _h F _i CH _(1-ef) Cl _e F _f = CH _(1-st) Cl _s F _t CH _(3-km) Cl _k F _m A chemical, wherein b, c are independently selected from 0, 1 or 2; e, f are independently selected from 0 or 1; h, i are independently selected from 0, 1, 2, 3; k, m are independently selected from and s, t are independently selected from 0 or 1. The refrigerant blend of claim 1 or claim 2, wherein the first composition comprises one or more refrigerants selected from the group consisting of R1233zd, R1336mzz, R1224yd, R1345zfc and/or R1233xf. The refrigerant blend of claim 1 or claim 2, wherein the second composition comprises a refrigerant selected from one or more of R1234yf, R1234ze, R32 and/or R134a. The refrigerant blend of claim 1 or claim 2, wherein the second composition includes at least one fluoroolefin. The refrigerant blend of claim 1 or claim 2, wherein the second composition includes a non-azeotrope having a bubble point in the range of -60°C to -15°C. The refrigerant blend of claim 1 or claim 2, wherein the second composition comprises an azeotrope having a bubble point in the range of -60°C to -15°C. The refrigerant blend of claim 1 or claim 2, wherein the second composition comprises refrigerant numbers 444A, 444B, 445A, 446A, 447A, 447B, 448A, 449A, 449B, 449C, 450A, 451A, as appropriate , 451B, 452A, 452B, 452C, 453A, 454A, 454B, 454C, 455A, 456A, 457A, 458A, 459A, 459B, 460A, 460B, 461A and/or a non-azeotrope of one or more of 462A; and/or an azeotrope selected from one or more of refrigerant numbers 513A, 513B, 515A and/or 516A. The refrigerant blend of claim 1 or claim 2, wherein the third composition comprises one or more refrigerants selected from R23, R469A, R508, ethane (R170) and/or ethylene (R1150). The refrigerant blend of claim 1 or claim 2, wherein the refrigerant blend does not contain R23, HFC32 and/or HFC365mfc. The refrigerant blend of claim 1 or claim 2, wherein the fourth composition comprises one or more of R14, R472A, methane and/or krypton. The refrigerant blend of claim 1 or claim 2, wherein the fifth composition comprises one or more of Ar, N ₂ and/or Ne. The refrigerant blend of claim 1 or claim 2, further comprising an oil in the range of approximately 1% to 10% by weight. The refrigerant blend of claim 17, wherein the oil comprises polyol ester (POE) oil and/or polyalkylene glycol (PAG) oil. Use of the refrigerant blend according to any of the preceding claims in a refrigeration plant comprising in a refrigeration plant having a liquid/vapor phase separator, a throttling device refrigeration system and/or a Clemanco type system One compressor cycle in an automatic refrigeration cascade. The use of claim 19 for achieving a freezing temperature below -90°C, optionally within the range of -90°C to -196°C. An apparatus containing a refrigerant blend as claimed in any one of the preceding claims 1 to 18, wherein the refrigeration apparatus comprises a refrigeration system having a liquid/vapor phase separator, a throttling device and/or a Clemanco type A compressor cycle in an automatic refrigeration cascade of the system. The refrigerating apparatus of claim 21, wherein the refrigerating apparatus alternately allows cold refrigerant or hot refrigerant to flow to an evaporator. The refrigeration equipment of claim 21 or 22, comprising an object cooled by the refrigerant, the object is at least one of the following: a. A metal element in a vacuum chamber that freezes and traps gas; b. a heat exchanger that removes heat from a primary fluid stream comprising at least one of a liquid, gas, condensed gas, and condensed gas mixture; c. A metal element having internal refrigerant flow channels and cooling at least one of a silicon wafer, a glass sheet, a plastic sheet, and an aluminum disk with or without a magnetic coating, as appropriate; and d. A biological refrigerator used to cool and/or store biological tissue.

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