KR20120102673A - Cascade refrigeration system with fluoroolefin refrigerant - Google Patents

Abstract

The present invention relates to a cascade refrigeration system for circulating a refrigerant comprising fluoroolefins. The cascade refrigeration system includes a low temperature freezing loop and a medium temperature freezing loop. The fluoroolefins circulate through either loop, or both loops. In certain embodiments, the fluoroolefins circulate through a mesophilic loop. In certain embodiments, when the cascade refrigeration system comprises a first cascade heat exchanger and a second cascade heat exchanger, and a second heat transfer loop extending between the first cascade heat exchanger and the second cascade heat exchanger, the first refrigerant and / or Or either of the second refrigerants may be a fluoroolefin, but need not necessarily be a fluoroolefin.

Description

Cascade refrigeration system with fluoroolefin refrigerants {CASCADE REFRIGERATION SYSTEM WITH FLUOROOLEFIN REFRIGERANT}

The present invention relates to a cascade refrigeration system for circulating a refrigerant comprising fluoroolefins. In particular, such cascade systems include a medium temperature loop and a low temperature loop, in which fluoroolefin refrigerants can be used in either or both loops.

Cascade refrigeration systems are known in the art and are described, for example, in ICR07-B2-358, "CO _{2 -} DX Systems for Medium-and Low-Temperature Refrigeration in Supermarket Applications", T. Sienel, O. Finckh, International Congress of Refrigeration, 2007, Beijing. Such systems typically have 1,1,1,2-tetrafluoroethane (R134a) or HFC-125 and HFC-143a (i.e., R404A) in a mesophilic loop, for example to provide cooling in a display case in a supermarket. Refrigerants such as blends), and refrigerants such as carbon dioxide (CO ₂ ) in the low temperature loop.

The refrigeration industry has been working for decades to find alternative refrigerants for ozone-destructive chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) that are being phased out as a result of the Montreal Protocol. have. The solution for most refrigerant producers is the commercialization of hydrofluorocarbon (HFC) refrigerants. HFC-134a, the new HFC refrigerant currently in widespread use, has a zero ozone depletion index and is therefore unaffected by the current regulatory phase out as a result of the Montreal Protocol.

Additional environmental regulations may ultimately lead to global phase out of certain HFC refrigerants. Currently, the automotive industry is facing regulations on the global warming potential because of the refrigerants used in automotive air conditioners. Thus, for the automotive air conditioner market there is a great need for finding new refrigerants with a reduced global warming index. If regulations are more widely applied in the future, for example for stationary air conditioning and refrigeration systems, there will be a greater need for refrigerants that can be used in all areas of the refrigeration and air conditioning industry.

Alternative refrigerants currently proposed for HFC-134a include HFC-152a, pure hydrocarbons such as butane or propane, or “natural” refrigerants such as CO ₂ . Many of these proposed replacements are toxic, flammable, and / or have low energy efficiency. Among other things, new alternatives have also been proposed for HCFC-22, R404A, R407C and R410A. As these alternatives are found, new alternatives for such alternative refrigerants are being sought to take advantage of their low or zero ozone depletion potential and lower global warming potential.

It is an object of the present invention to provide a cascade refrigeration system using a refrigerant composition having unique features that meet the needs of a lower global warming index and a lower or zero ozone depletion index compared to current refrigerants.

In addition to the lower global warming index advantages, the cascade refrigeration system of the present invention may have higher energy efficiency and capacity than currently used cascade refrigeration systems.

Thus, according to the present invention there is provided a cascade refrigeration system having at least two refrigeration loops each circulating a refrigerant,

(a) a first expansion device for reducing the pressure and temperature of the first refrigerant liquid;

(b) an evaporator having an inlet and an outlet, wherein the first refrigerant liquid from the first expansion device enters the evaporator through the evaporator inlet and evaporates within the evaporator to form a first refrigerant vapor, thereby producing cooling and exiting to the outlet Circulating-;

(c) a first compressor having an inlet and an outlet, wherein the first refrigerant vapor from the evaporator is circulated and compressed to the inlet of the first compressor, thereby increasing the pressure and temperature of the first refrigerant vapor and compressing the first refrigerant Steam circulates to the outlet of the first compressor;

(d) Cascade Heat Exchanger System-The Cascade Heat Exchanger System,

(i) a first inlet and a first outlet, wherein the first refrigerant vapor circulates from the first inlet to the first outlet and condenses in the heat exchanger system to form a first refrigerant liquid, thereby releasing heat; and

(ii) a second inlet and a second outlet, wherein the second refrigerant liquid circulates from the second inlet to the second outlet and absorbs the heat released by the first refrigerant to form a second refrigerant vapor; ;

(e) a second compressor having an inlet and an outlet, wherein the second refrigerant vapor from the cascade heat exchanger system is sucked into the compressor and compressed to increase the pressure and temperature of the second refrigerant vapor;

(f) a condenser having an inlet and an outlet for circulating the second refrigerant vapor and condensing the second refrigerant vapor from the compressor to form a second refrigerant liquid, wherein the second refrigerant liquid exits the condenser through the condenser outlet Exit-; And

(g) A system is provided that includes a second expansion device that exits the condenser and reduces the pressure and temperature of the second refrigerant liquid entering the second inlet of the cascade heat exchanger system.

Either or both of the first or second refrigerant may comprise fluoroolefins.

In a particular embodiment, the cascade heat exchanger system can include a first cascade heat exchanger and a second cascade heat exchanger, and a secondary heat transfer loop extending between the first cascade heat exchanger and the second cascade heat exchanger. In this embodiment, the second refrigerant liquid indirectly absorbs the heat released by the first refrigerant vapor through the heat transfer fluid circulating between the first cascade heat exchanger and the second cascade heat exchanger through the secondary heat transfer loop. The first cascade heat exchanger has a first inlet and a first outlet and a second inlet and a second outlet, wherein the first refrigerant vapor circulates from the first inlet to the first outlet and condenses by dissipating heat, condensing the secondary heat transfer fluid Circulates from the second inlet to the second outlet, absorbs the heat released from the first refrigerant vapor and circulates to the second cascade heat exchanger. The second cascade heat exchanger has a first inlet and a first outlet and a second inlet and a second outlet, wherein the heat transfer fluid is from the second outlet of the first cascade heat exchanger to the first inlet of the second cascade heat exchanger and the second It circulates to the first outlet of the cascade heat exchanger and releases the heat absorbed from the first refrigerant. The second refrigerant liquid circulates from the second inlet of the second cascade heat exchanger to the second outlet and absorbs the heat released by the heat transfer fluid to form the second refrigerant vapor. In such embodiments, either the first refrigerant and / or the second refrigerant may be fluoroolefins, but need not necessarily be fluoroolefins.

Also according to the invention, a method of exchanging heat between at least two refrigeration loops,

(a) absorbing heat from the object to be cooled in the first freezing loop and dissipating this heat to the second freezing loop; And

(b) absorbing heat from the first freezing loop and dissipating this heat to the surroundings in a second freezing loop,

A method is provided wherein the refrigerant in at least one of the refrigeration loops comprises fluoroolefins.

The invention can be better understood with reference to the following figures.
≪ 1 >
1 is a schematic diagram of a cascade refrigeration system according to one embodiment of the invention.
2,
2 is a schematic representation of another embodiment of the cascade refrigeration system of the present invention.
3,
3 is a schematic diagram of a further embodiment of the present invention showing a cascade refrigeration system having a secondary heat transfer loop that transfers heat from a lower temperature loop to a higher temperature loop.
<Fig. 4>
4 is a schematic representation of another embodiment of a cascade refrigeration system of the present invention having multiple cold loops.
5,
FIG. 5 is a graph of cooling capacity and COP versus weight percent of HFO-1234yf in the composition for refrigerant compositions comprising HFO-1234yf and HFC-134a.

Before discussing the details of the embodiments described below, some terms will be defined or clarified.

The refrigeration capacity (also referred to as cooling capacity) is the change in enthalpy of refrigerant in the evaporator per unit mass of refrigerant circulated, or removed by the refrigerant in the evaporator per unit volume of refrigerant vapor exiting the evaporator. It is a term to define the heat (volume capacity) to be. Refrigeration capacity is a measure of the ability of a refrigerant or heat transfer composition to produce cooling. Thus, the higher this capacity, the greater the cooling produced for a given refrigerant circulation rate. Cooling rate refers to the heat removed by the refrigerant in the evaporator per unit time.

The coefficient of performance (COP) is the amount of heat removed from the object to be cooled divided by the energy input required to operate the cycle over a given time interval. The higher the COP, the higher the energy efficiency. COP is directly related to the energy efficiency ratio (EER), which is an efficiency assessment for refrigeration or air conditioning equipment at a particular set of internal and external temperatures.

The global warming potential (GWP) is an index for assessing the relative contribution of global warming to the emissions of one kilogram of certain greenhouse gases to the atmosphere, compared to the emissions of one kilogram of carbon dioxide. GWP can be calculated over several time horizons showing the effect of atmospheric life on a given gas. The GWP for a 100-year clock is the standard value. In the case of a mixture, a mass-fraction weighted average can be calculated based on the individual GWPs for each component.

Ozone depletion potential (ODP) is a number that indicates the amount of stratospheric ozone depletion caused by a substance. ODP is the ratio of the effect of chemicals to stratospheric ozone compared to the effect of CFC-11 (fluorotrichloromethane) of similar mass. Therefore, the ODP of CFC-11 is defined to be 1.0. Other CFCs and HCFCs have ODPs ranging from 0.01 to 1.0. OFC is zero because HFC does not contain chlorine.

As used herein, the terms “comprises”, “comprising”, “includes”, “comprising”, “haves”, “haves”, or any other variation thereof encompasses non-exclusive inclusions. It is intended to be. For example, a composition, process, method, article, or device that includes a list of elements is not necessarily limited to these elements, and is not explicitly listed or otherwise inherent in such composition, process, method, article, or device. It can contain elements. Also, unless expressly stated to the contrary, "or" refers to an inclusive "or" and not an exclusive "or". For example, condition A or B is satisfied by any one of the following: A is true (or present), B is false (or not present), A is false (or not present) B is true (or present), and both A and B are true (or present).

The transition phrase “consisting of” excludes any element, step, or ingredient not specified. When in the claims, such phrases typically block the claims for inclusion of materials other than those listed, except for related impurities. If the phrase "consist of" appears in a section of the body of the claim and not immediately after the preamble, the phrase only restricts the elements described in that section, and other elements are not excluded from the claim as a whole.

The phrase "consisting essentially of" is a composition, method or device comprising a substance, step, feature, component, or element in addition to those disclosed in the text-additional such substances, steps, features, components, or elements included. Is used to define if-substantially affects the basic and novel feature (s) of the claimed invention. The term “consisting essentially of” takes an intermediate position between “comprising” and “consisting of”.

Where the applicant has defined an invention or part thereof in an open term such as "comprising", the description (unless otherwise stated) refers to describing the invention also using the terms "consisting essentially of" or "consisting of." It should be easily understood that it should be interpreted.

In addition, the use of indefinite articles ("a" or "an") is employed to describe the elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. Such descriptions should be understood to include one or at least one, and the singular also includes the plural unless it is obvious that it is meant otherwise.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the disclosed compositions, suitable methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety unless specific passages are cited. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.

According to the present invention there is provided a cascade refrigeration system having at least two refrigeration loops-for circulating refrigerant through each loop. Such a cascade system is shown schematically at 10 in FIG. 1. The cascade refrigeration system of the present invention comprises a first or lower loop 12 as shown in FIG. 1, which is a cold loop, and a second or upper loop 14 as shown in FIG. 14) with at least two refrigeration loops. Each loop circulates refrigerant through the loop.

As shown in FIG. 1, the cascade refrigeration system of the present invention includes a first expansion device 16. The first expansion device has an inlet 16a and an outlet 16b. The first expansion device reduces the pressure and temperature of the first refrigerant liquid circulating through the first or cold loop.

The cascade refrigeration system of the present invention also includes an evaporator 18 as shown in FIG. The evaporator has an inlet 18a and an outlet 18b. The first refrigerant liquid from the first expansion device enters the evaporator through the evaporator inlet and evaporates within the evaporator to form the first refrigerant vapor. This creates cooling in the first or low temperature circuit in the object to be cooled, such as food in the cold display case. The first refrigerant vapor then circulates to the outlet of the evaporator.

The cascade refrigeration system of the present invention also includes a first compressor 20. The first compressor has an inlet 20a and an outlet 20b. The first refrigerant vapor from the evaporator is circulated and compressed to the inlet of the first compressor, thereby increasing the pressure and temperature of the first refrigerant vapor. The compressed first refrigerant vapor then circulates to the outlet of the first compressor.

The cascade refrigeration system of the present invention also includes a cascade heat exchanger system 22. The heat exchanger has a first inlet 22a and a first outlet 22b. The first refrigerant vapor from the first compressor enters the first inlet of the heat exchanger and condenses in the heat exchanger to form a first refrigerant liquid, thereby dissipating heat. The first refrigerant liquid then circulates to the first outlet of the heat exchanger. The heat exchanger also includes a second inlet 22c and a second outlet 22d. The second refrigerant liquid circulates from the second inlet of the heat exchanger to the second outlet and evaporates to form a second refrigerant vapor, absorbing the heat released by the first refrigerant (when the first refrigerant is condensed). This heat is released to the environment. The second refrigerant vapor then circulates to the second outlet of the heat exchanger. Thus, in the embodiment of FIG. 1, heat released by the first refrigerant is directly absorbed by the second refrigerant, and this heat is released to the surroundings.

The cascade refrigeration system of the present invention also includes a second compressor 24 as shown in FIG. The second compressor has an inlet 24a and an outlet 24b. The second refrigerant vapor from the cascade heat exchanger is drawn into the compressor through the inlet and compressed, thereby increasing the pressure and temperature of the second refrigerant vapor. The second refrigerant vapor then circulates to the outlet of the second compressor.

The cascade refrigeration system of the present invention also includes a condenser 26 having an inlet 26a and an outlet 26b. The second refrigerant from the second compressor circulates from the inlet and condenses in the condenser to form a second refrigerant liquid. The second refrigerant liquid exits the condenser through the outlet.

The cascade refrigeration system of the present invention also includes a second expansion device 28 having an inlet 28a and an outlet 28b. The second refrigerant liquid passes through the second expansion device, which reduces the pressure and temperature of the second refrigerant liquid exiting the condenser. Such liquid may be partially vaporized during this expansion. The second refrigerant liquid of reduced pressure and temperature circulates from the expansion device to the second inlet of the cascade heat exchanger system.

It should be noted that various changes to the embodiment as shown in FIG. 1 may be made without departing from the spirit or scope of the invention. For example, as shown in the cascade refrigeration system diagram of the publication titled "Price Chopper Remodel Features Hill Phoenix Next Generation Refrigeration System", May 5, 2008, multiple cascade heat exchangers, instead of a single cascade heat exchanger, and It may be possible to include multiple first compressors instead of a single first compressor. In addition, secondary heat transfer loops, such as those shown in this diagram, that use a secondary heat transfer fluid, such as glycol, transfer heat from the object to be cooled (e.g., supermarket food display case) into a hot freezing loop and a cold freezing loop. It can be used with the system of the present invention for delivery to either or both. In this case, as described below with respect to FIG. 3, this secondary heat transfer loop, as opposed to the secondary heat transfer loop used to transfer heat between the freezing loops, cools the heat from the object to be cooled. Used to pass by.

According to the present invention, either the first refrigerant or the second refrigerant in the cascade system of the embodiment of FIG. 1 may comprise fluoroolefins. In particular, the at least second refrigerant, ie the refrigerant circulating through the mesophilic loop, comprises fluoroolefins. However, it is within the scope of the present invention that the first refrigerant, ie the refrigerant in the low temperature loop, comprises fluoroolefins. It is also within the scope of the present invention that both the first and second refrigerants comprise fluoroolefins. Additionally, in some embodiments, the first or second refrigerant can be any of the fluoroolefins, or a mixture of fluoroolefins, or a mixture of fluoroolefins and additional refrigerants as described herein. have.

Such fluoroolefins may be selected from the group consisting of:

(i) fluoroolefins of the formula E- or ZR ¹ CH = CHR ² , wherein R ¹ and R ² are independently C ₁ to C ₆ perfluoroalkyl groups;

(ii) cyclic fluoroolefins of the formula cyclo- [CX = CY (CZW) _n- ] wherein X, Y, Z, and W are independently H or F and n is an integer from 2 to 5; And

(iii) tetrafluoroethylene (CF ₂ = CF ₂ ); Hexafluoropropene (CF ₃ CF = CF ₂ ); 1,2,3,3,3-pentafluoro-1-propene (CHF = CFCF ₃ ), 1,1,3,3,3-penta Fluoro-1-propene (CF ₂ = CHCF ₃ ), 1,1,2,3,3-pentafluoro-1-propene (CF ₂ = CFCHF ₂ ), 1,2,3,3-tetra Fluoro-1-propene (CHF = CFCHF ₂ ), 2,3,3,3-tetrafluoro-1-propene (CH ₂ = CFCF ₃ ), 1,3,3,3-tetrafluoro- 1-propene (CHF = CHCF ₃ ), 1,1,2,3-tetrafluoro-1-propene (CF ₂ = CFCH ₂ F), 1,1,3,3-tetrafluoro-1- Propene (CF ₂ = CHCHF ₂ ), 1,2,3,3-tetrafluoro-1-propene (CHF = CFCHF ₂ ), 3,3,3-trifluoro-1-propene (CH ₂ = CHCF ₃ ), 2,3,3-trifluoro-1-propene (CHF ₂ CF = CH ₂ ); 1,1,2-trifluoro-1-propene (CH ₃ CF = CF ₂ ); 1,2,3-trifluoro-1-propene (CH ₂ FCF = CF ₂ ); 1,1,3-trifluoro-1-propene (CH ₂ FCH = CF ₂ ); 1,3,3-trifluoro-1-propene (CHF ₂ CH = CHF); 1,1,1,2,3,4,4,4-octafluoro-2-butene (CF ₃ CF = CFCF ₃ ); 1,1,2,3,3,4,4,4-octafluoro-1-butene (CF ₃ CF ₂ CF = CF ₂ ); 1,1,1,2,4,4,4-heptafluoro-2-butene (CF ₃ CF = CHCF ₃ ); 1,2,3,3,4,4,4-heptafluoro-1-butene (CHF = CFCF ₂ CF ₃ ); 1,1,1,2,3,4,4-heptafluoro- ₂ -butene (CHF ₂ CF = CFCF ₃ ); 1,3,3,3-tetrafluoro-2- (trifluoromethyl) -1-propene ((CF ₃ ) ₂ C = CHF); 1,1,3,3,4,4,4-heptafluoro-1-butene (CF ₂ = CHCF ₂ CF ₃ ); 1,1,2,3,4,4,4-heptafluoro-1-butene (CF ₂ = CFCHFCF ₃ ); 1,1,2,3,3,4,4-heptafluoro-1-butene (CF ₂ = CFCF ₂ CHF ₂ ); 2,3,3,4,4,4-hexafluoro-1-butene (CF ₃ CF ₂ CF = CH ₂ ); 1,3,3,4,4,4-hexafluoro-1-butene (CHF = CHCF ₂ CF ₃ ); 1,2,3,4,4,4-hexafluoro-1-butene (CHF = CFCHFCF ₃ ); 1,2,3,3,4,4-hexafluoro-1-butene (CHF = CFCF ₂ CHF ₂ ); 1,1,2,3,4,4-hexafluoro- ₂ -butene (CHF ₂ CF = CFCHF ₂ ); 1,1,1,2,3,4-hexafluoro- ₂ -butene (CH ₂ FCF = CFCF ₃ ); 1,1,1,2,4,4-hexafluoro- ₂ -butene (CHF ₂ CH = CFCF ₃ ); 1,1,1,3,4,4-hexafluoro-2-butene (CF ₃ CH = CFCHF ₂ ); 1,1,2,3,3,4-hexafluoro-1-butene (CF ₂ = CFCF ₂ CH ₂ F); 1,1,2,3,4,4-hexafluoro-1-butene (CF ₂ = CFCHFCHF ₂ ); 3,3,3-trifluoro-2- (trifluoromethyl) -1-propene (CH ₂ = C (CF ₃ ) ₂ ); 1,1,1,2,4-pentafluoro- ₂ -butene (CH ₂ FCH = CFCF ₃ ); 1,1,1,3,4-pentafluoro-2-butene (CF ₃ CH = CFCH ₂ F); 3,3,4,4,4-pentafluoro-1-butene (CF ₃ CF ₂ CH = CH ₂ ); 1,1,1,4,4-pentafluoro- ₂ -butene (CHF ₂ CH = CHCF ₃ ); 1,1,1,2,3-pentafluoro-2-butene (CH ₃ CF = CFCF ₃ ); 2,3,3,4,4-pentafluoro-1-butene (CH ₂ = CFCF ₂ CHF ₂ ); 1,1,2,4,4-pentafluoro- ₂ -butene (CHF ₂ CF = CHCHF ₂ ); 1,1,2,3,3-pentafluoro-1-butene (CH ₃ CF ₂ CF = CF ₂ ); 1,1,2,3,4-pentafluoro- ₂ -butene (CH ₂ FCF = CFCHF ₂ ); 1,1,3,3,3-pentafluoro-2-methyl-1-propene (CF ₂ = C (CF ₃ ) (CH ₃ )); 2- (difluoromethyl) -3,3,3-trifluoro-1-propene (CH ₂ = C (CHF ₂ ) (CF ₃ )); 2,3,4,4,4-pentafluoro-1-butene (CH ₂ = CFCHFCF ₃ ); 1,2,4,4,4-pentafluoro-1-butene (CHF = CFCH ₂ CF ₃ ); 1,3,4,4,4-pentafluoro-1-butene (CHF = CHCHFCF ₃ ); 1,3,3,4,4-pentafluoro-1-butene (CHF = CHCF ₂ CHF ₂ ); 1,2,3,4,4-pentafluoro-1-butene (CHF = CFCHFCHF ₂ ); 3,3,4,4-tetrafluoro-1-butene (CH ₂ = CHCF ₂ CHF ₂ ); 1,1-difluoro-2- (difluoromethyl) -1-propene (CF ₂ = C (CHF ₂ ) (CH ₃ )); 1,3,3,3-tetrafluoro-2-methyl-1-propene (CHF = C (CF ₃ ) (CH ₃ )); 3,3-difluoro-2- (difluoromethyl) -1-propene (CH ₂ = C (CHF ₂ ) ₂ ); 1,1,1,2-tetrafluoro-2-butene (CF ₃ CF═CHCH ₃ ); 1,1,1,3-tetrafluoro-2-butene (CH ₃ CF = CHCF ₃ ); 1,1,1,2,3,4,4,5,5,5-decafluoro- ₂ -pentene (CF ₃ CF = CFCF ₂ CF ₃ ); 1,1,2,3,3,4,4,5,5,5-decafluoro-1-pentene (CF ₂ = CFCF ₂ CF ₂ CF ₃ ); 1,1,1,4,4,4-hexafluoro-2- (trifluoromethyl) -2-butene ((CF ₃ ) ₂ C = CHCF ₃ ); 1,1,1,2,4,4,5,5,5-nonnafluoro-2-pentene (CF ₃ CF = CHCF ₂ CF ₃ ); 1,1,1,3,4,4,5,5,5-nonnafluoro- ₂ -pentene (CF ₃ CH = CFCF ₂ CF ₃ ); 1,2,3,3,4,4,5,5,5-nonnafluoro-1-pentene (CHF = CFCF ₂ CF ₂ CF ₃ ); 1,1,3,3,4,4,5,5,5-nonnafluoro-1-pentene (CF ₂ = CHCF ₂ CF ₂ CF ₃ ); 1,1,2,3,3,4,4,5,5-nonnafluoro-1-pentene (CF ₂ = CFCF ₂ CF ₂ CHF ₂ ); 1,1,2,3,4,4,5,5,5-nonnafluoro- ₂ -pentene (CHF ₂ CF = CFCF ₂ CF ₃ ); 1,1,1,2,3,4,4,5,5-nonnafluoro- ₂ -pentene (CF ₃ CF = CFCF ₂ CHF ₂ ); 1,1,1,2,3,4,5,5,5-nonnafluoro-2-pentene (CF ₃ CF = CFCHFCF ₃ ); 1,2,3,4,4,4-hexafluoro-3- (trifluoromethyl) -1-butene (CHF = CFCF (CF ₃ ) ₂ ); 1,1,2,4,4,4-hexafluoro-3- (trifluoromethyl) -1-butene (CF ₂ = CFCH (CF ₃ ) ₂ ); 1,1,1,4,4,4-hexafluoro-2- (trifluoromethyl) -2-butene (CF ₃ CH = C (CF ₃ ) ₂ ); 1,1,3,4,4,4-hexafluoro-3- (trifluoromethyl) -1-butene (CF ₂ = CHCF (CF ₃ ) ₂ ); 2,3,3,4,4,5,5,5-octafluoro-1-pentene (CH ₂ = CFCF ₂ CF ₂ CF ₃ ); 1,2,3,3,4,4,5,5-octafluoro-1-pentene (CHF = CFCF ₂ CF ₂ CHF ₂ ); 3,3,4,4,4-pentafluoro-2- (trifluoromethyl) -1-butene (CH ₂ = C (CF ₃ ) CF ₂ CF ₃ ); 1,1,4,4,4-pentafluoro-3- (trifluoromethyl) -1-butene (CF ₂ = CHCH (CF ₃ ) ₂ ); 1,3,4,4,4-pentafluoro-3- (trifluoromethyl) -1-butene (CHF = CHCF (CF ₃ ) ₂ ); 1,1,4,4,4-pentafluoro-2- (trifluoromethyl) -1-butene (CF ₂ = C (CF ₃ ) CH ₂ CF ₃ ); 3,4,4,4-tetrafluoro-3- (trifluoromethyl) -1-butene ((CF ₃ ) ₂ CFCH = CH ₂ ); 3,3,4,4,5,5,5-heptafluoro-1-pentene (CF ₃ CF ₂ CF ₂ CH = CH ₂ ); 2,3,3,4,4,5,5-heptafluoro-1-pentene (CH ₂ = CFCF ₂ CF ₂ CHF ₂ ); 1,1,3,3,5,5,5-heptafluoro-1-butene (CF ₂ = CHCF ₂ CH ₂ CF ₃ ); 1,1,1,2,4,4,4-heptafluoro-3-methyl-2-butene (CF ₃ CF═C (CF ₃ ) (CH ₃ )); 2,4,4,4-tetrafluoro-3- (trifluoromethyl) -1-butene (CH ₂ = CFCH (CF ₃ ) ₂ ); 1,4,4,4-tetrafluoro-3- (trifluoromethyl) -1-butene (CHF = CHCH (CF ₃ ) ₂ ); 1,1,1,4-tetrafluoro-2- (trifluoromethyl) -2-butene (CH ₂ FCH = C (CF ₃ ) ₂ ); 1,1,1,3-tetrafluoro-2- (trifluoromethyl) -2-butene (CH ₃ CF═C (CF ₃ ) ₂ ); 1,1,1-trifluoro-2- (trifluoromethyl) -2-butene ((CF ₃ ) ₂ C = CHCH ₃ ); 3,4,4,5,5,5-hexafluoro-2-pentene (CF ₃ CF ₂ CF = CHCH ₃ ); 1,1,1,4,4,4-hexafluoro-2-methyl-2-butene (CF ₃ C (CH ₃ ) = CHCF ₃ ); 3,3,4,5,5,5-hexafluoro-1-pentene (CH ₂ = CHCF ₂ CHFCF ₃ ); 4,4,4-trifluoro-2- (trifluoromethyl) -1-butene (CH ₂ = C (CF ₃ ) CH ₂ CF ₃ ); 1,1,2,3,3,4,4,5,5,6,6,6-dodecafluoro-1-hexene (CF ₃ (CF ₂ ) ₃ CF = CF ₂ ); 1,1,1,2,2,3,4,5,5,6,6,6-dodecafluoro-3-hexene (CF ₃ CF ₂ CF = CFCF ₂ CF ₃ ); 1,1,1,4,4,4-hexafluoro-2,3-bis (trifluoromethyl) -2-butene ((CF ₃ ) ₂ C═C (CF ₃ ) ₂ ); 1,1,1,2,3,4,5,5,5-nonnafluoro-4- (trifluoromethyl) -2-pentene ((CF ₃ ) ₂ CFCF = CFCF ₃ ); 1,1,1,4,4,5,5,5-octafluoro-2- (trifluoromethyl) -2-pentene ((CF ₃ ) ₂ C = CHC ₂ F ₅ ); 1,1,1,3,4,5,5,5-octafluoro-4- (trifluoromethyl) -2-pentene ((CF ₃ ) ₂ CFCF = CHCF ₃ ); 3,3,4,4,5,5,6,6,6-nonnafluoro-1-hexene (CF ₃ CF ₂ CF ₂ CF ₂ CH = CH ₂ ); 4,4,4-trifluoro-3,3-bis (trifluoromethyl) -1-butene (CH ₂ = CHC (CF ₃ ) ₃ ); 1,1,1,4,4,4-hexafluoro-3-methyl-2- (trifluoromethyl) -2-butene ((CF ₃ ) ₂ C = C (CH ₃ ) (CF ₃ )) ; 2,3,3,5,5,5-hexafluoro-4- (trifluoromethyl) -1-pentene (CH ₂ = CFCF ₂ CH (CF ₃ ) ₂ ); 1,1,1,2,4,4,5,5,5-nonnafluoro-3-methyl-2-pentene (CF ₃ CF = C (CH ₃ ) CF ₂ CF ₃ ); 1,1,1,5,5,5-hexafluoro-4- (trifluoromethyl) -2-pentene (CF ₃ CH = CHCH (CF ₃ ) ₂ ); 3,4,4,5,5,6,6,6-octafluoro-2-hexene (CF ₃ CF ₂ CF ₂ CF = CHCH ₃ ); 3,3,4,4,5,5,6,6-octafluoro1-hexene (CH ₂ = CHCF ₂ CF ₂ CF ₂ CHF ₂ ); 1,1,1,4,4-pentafluoro-2- (trifluoromethyl) -2-pentene ((CF ₃ ) ₂ C = CHCF ₂ CH ₃ ); 4,4,5,5,5-pentafluoro-2- (trifluoromethyl) -1-pentene (CH ₂ = C (CF ₃ ) CH ₂ C ₂ F ₅ ); 3,3,4,4,5,5,5-heptafluoro-2-methyl-1-pentene (CF ₃ CF ₂ CF ₂ C (CH ₃ ) = CH ₂ ); 4,4,5,5,6,6,6-heptafluoro-2-hexene (CF ₃ CF ₂ CF ₂ CH = CHCH ₃ ); 4,4,5,5,6,6,6-heptafluoro-1-hexene (CH ₂ = CHCH ₂ CF ₂ C ₂ F ₅ ); 1,1,1,2,2,3,4-heptafluoro-3-hexene (CF ₃ CF ₂ CF = CFC ₂ H ₅ ); 4,5,5,5-tetrafluoro-4- (trifluoromethyl) -1-pentene (CH ₂ = CHCH ₂ CF (CF ₃ ) ₂ ); 1,1,1,2,5,5,5-heptafluoro-4-methyl-2-pentene (CF ₃ CF = CHCH (CF ₃ ) (CH ₃ )); 1,1,1,3-tetrafluoro-2- (trifluoromethyl) -2-pentene ((CF ₃ ) ₂ C = CFC ₂ H ₅ ); 1,1,1,2,3,4,4,5,5,6,6,7,7,7-tetradecafluoro-2-heptene (CF ₃ CF = CFCF ₂ CF ₂ C ₂ F ₅ ) ; 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene (CF ₃ CF ₂ CF = CFCF ₂ C ₂ F ₅ ) ; 1,1,1,3,4,4,5,5,6,6,7,7,7-tridecafluoro-2-heptene (CF ₃ CH = CFCF ₂ CF ₂ C ₂ F ₅ ); 1,1,1,2,4,4,5,5,6,6,7,7,7-tridecafluoro-2-heptene (CF ₃ CF = CHCF ₂ CF ₂ C ₂ F ₅ ); 1,1,1,2,2,4,5,5,6,6,7,7,7-tridecafluoro-3-heptene (CF ₃ CF ₂ CH = CFCF ₂ C ₂ F ₅ ); And 1,1,1,2,2,3,5,5,6,6,7,7,7-tridecafluoro-3-heptene (CF ₃ CF ₂ CF = CHCF ₂ C ₂ F ₅ ) Fluoroolefins selected from the group consisting of:

In some embodiments, the fluoroolefin is a compound comprising a carbon atom, a fluorine atom, and optionally a hydrogen or chlorine atom. In one embodiment, the fluoroolefins used in the compositions of the present invention include compounds having 2 to 12 carbon atoms. In another embodiment, the fluoroolefins include compounds having 3 to 10 carbon atoms, and in yet another embodiment, the fluoroolefins include compounds having 3 to 7 carbon atoms. Representative fluoroolefins include, but are not limited to, all compounds as listed in Tables 1, 2, and 3.

In one embodiment of the invention, the first refrigerant is selected from fluoroolefins having the formula E- or ZR ¹ CH = CHR ² (formula (i)), wherein R ¹ and R ² are independently C ₁ To C ₆ perfluoroalkyl group. Examples of groups R ¹ and R ² include CF ₃ , C ₂ F _5, CF ₂ CF ₂ CF ₃ , CF (CF ₃ ) ₂ , CF ₂ CF ₂ CF ₂ CF ₃ , CF (CF ₃ ) CF ₂ CF ₃ , CF ₂ CF (CF ₃ ) ₂ , C (CF ₃ ) ₃ , CF ₂ CF ₂ CF ₂ CF ₂ CF ₃ , CF ₂ CF ₂ CF (CF ₃ ) ₂ , C (CF ₃ ) ₂ C ₂ F ₅ , CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ CF ₃ , CF (CF ₃ ) CF ₂ CF ₂ C ₂ F ₅ , and C (CF ₃ ) ₂ CF ₂ C ₂ F ₅ , including but not limited to. In one embodiment, the fluoroolefins of formula (i) have four or more carbon atoms in the molecule. In another embodiment, the first refrigerant is selected from fluoroolefins of formula (i) having at least 5 carbon atoms in the molecule. In another embodiment, the first refrigerant is selected from fluoroolefins of formula (i) having at least 6 carbon atoms in the molecule. Exemplary and non-limiting compounds of Formula (i) are shown in Table 1.

(I), the compound is a tri-dihydro-iodo of formula R ¹ CH ₂ CHIR ² is contacted with an alkyl tri-dihydro-olefin perfluoroalkyl of general formula R ¹ I perfluoroalkyl iodide Id formula R ² CH = with CH ₂ of It can be prepared by forming a perfluoroalkane. Such trihydroiodoperfluoroalkanes may then be dehydroiodination to form R ¹ CH═CHR ² . Alternatively, the olefin R ¹ CH = CHR ² is the formula R ¹ is consequently formed by an alkyl tri-dihydro-olefin and the reaction perfluoroalkyl of formula R ² I of the formula with an alkyl iodide perfluoro R ¹ CH = CH ₂ It can be prepared by dehydroiodation of trihydroiodoperfluoroalkane of CHICH ₂ R ² .

Contact of the perfluoroalkyl iodide with the perfluoroalkyltrihydroolefin takes place in a batch mode by combining the reactants in a suitable reaction vessel that can operate under autogenous pressure of the reactants and the product at the reaction temperature. Can be. Suitable reaction vessels include, in particular, austenitic stainless steels, and well-known high nickel alloys such as Monel® nickel-copper alloys, Hastelloy® nickel-based alloys and inconels (Inconel®) includes those made of nickel-chromium alloys.

Alternatively, the reaction may be carried out in a semi-batch manner in which the perfluoroalkyltrihydroolefin reactant is added to the perfluoroalkyl iodide reactant by a suitable addition device such as a pump at the reaction temperature.

The ratio of perfluoroalkyl iodide to perfluoroalkyltrihydroolefin should be about 1: 1 to about 4: 1, preferably about 1.5: 1 to 2.5: 1. A ratio of less than 1.5: 1 is described by Jeanneaux, et. al. in Journal of Fluorine Chemistry , Vol. 4, pages 261-270 (1974), tend to result in large amounts of 2: 1 adducts.

The preferred temperature for contacting the perfluoroalkyl iodide with the perfluoroalkyltrihydroolefin is preferably in the range of about 150 ° C to 300 ° C, preferably about 170 ° C to about 250 ° C, and most Preferably from about 180 ° C to about 230 ° C.

Suitable contact times for the reaction of perfluoroalkyl iodide and perfluoroalkyltrihydroolefin are from about 0.5 hours to 18 hours, preferably from about 4 hours to about 12 hours.

Trihydroiodoperfluoroalkanes prepared by the reaction of perfluoroalkyl iodides with perfluoroalkyltrihydroolefins can be used directly in the dehydroiodation step, or preferably in distillation prior to the dehydroiodation step Can be recovered and purified.

The dehydroiodination step is carried out by contacting trihydroiodoperfluoroalkane with a basic substance. Suitable basic materials include alkali metal hydroxides (eg sodium or potassium hydroxide), alkali metal oxides (eg sodium oxide), alkaline earth metal hydroxides (eg calcium hydroxide), alkaline earth metal oxides (eg Calcium oxide), alkali metal alkoxides (eg sodium methoxide or sodium ethoxide), aqueous ammonia, sodium amide, or mixtures of basic materials such as soda lime. Preferred basic materials are sodium hydroxide and potassium hydroxide.

Said contacting of the trihydroiodoperfluoroalkane with the basic substance may occur in the liquid phase, preferably in the presence of a solvent capable of dissolving at least a portion of both reactants. Suitable solvents for the dehydroiodination step include one or more polar organic solvents such as alcohols (eg, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, and tertiary butanol), nitrile (eg For example, acetonitrile, propionitrile, butyronitrile, benzonitrile, or adiponitrile), dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, or sulfolane This includes. The choice of solvent may depend on the boiling point of the product and the ease of separation of trace solvents from the product during purification. Typically, ethanol or isopropanol is a good solvent for the reaction.

Typically, the dehydroiodination reaction can be carried out by adding one of the reactants (either basic material or trihydroiodoperfluoroalkane) to the other reactants in a suitable reaction vessel. The reaction vessel may be made of glass, ceramic, or metal and is preferably stirred with an impeller or stirring mechanism.

Suitable temperatures for the dehydroiodination reaction are from about 10 ° C to about 100 ° C, preferably from about 20 ° C to about 70 ° C. The dehydroiodination reaction can be carried out at ambient pressure or at reduced or elevated pressure. Of note is a dehydroiodination reaction in which the compound of formula (i) is distilled from the reaction vessel when the compound of formula (i) is formed.

Alternatively, the dehydroiodination reaction may be performed by treating an aqueous solution of the basic material with an alkane (eg hexane, heptane, or octane), an aromatic hydrocarbon (eg toluene), a halogenated hydrocarbon (eg Methylene chloride, chloroform, carbon tetrachloride, or perchloroethylene), or ethers (eg, diethyl ether, methyl tert-butyl ether, tetrahydrofuran, 2-methyl tetrahydrofuran, dioxane, dimethoxyethane, Or a solution of trihydroiodoperfluoroalkane in one or more organic solvents of lower polarity such as diglyme, or tetraglyme). Suitable phase transfer catalysts include quaternary ammonium halides (eg, tetrabutylammonium bromide, tetrabutylammonium hydrosulfate, triethylbenzylammonium chloride, dodecyltrimethylammonium chloride, and tricaprylylmethylammonium chloride), quaternary Phosphonium halides (eg triphenylmethylphosphonium bromide and tetraphenylphosphonium chloride), or cyclic polys known in the art as crown ethers (eg 18-crown-6 and 15-crown-5) Ether compounds are included.

Alternatively, the dehydroiodination reaction can be carried out in the absence of solvent by adding trihydroiodoperfluoroalkane to the solid or liquid basic material.

Suitable reaction times for the dehydroiodination reaction are from about 15 minutes to about 6 hours or more, depending on the solubility of the reactants. Typically, the dehydroiodination reaction is rapid and requires about 30 minutes to about 3 hours to complete. The compound of formula (i) may be recovered from the dehydroiodation reaction mixture by phase separation after addition of water, by distillation, or by a combination thereof.

In another embodiment of the invention, the first refrigerant is selected from fluoroolefins comprising cyclic fluoroolefins (cyclo- [CX = CY (CZW) _n− ] (Formula (ii)), wherein X, Y, Z, and W are independently selected from H and F, n is an integer from 2 to 5. In one embodiment, the fluoroolefins of formula (ii) have at least about 3 carbon atoms in the molecule. In a form, the fluoroolefins of formula (ii) have at least about 4 carbon atoms in the molecule In another embodiment, the fluoroolefins of formula (ii) have at least about 5 carbon atoms in the molecule. In an embodiment, the fluoroolefins of formula (ii) have at least about 6 carbon atoms in the molecule Representative cyclic fluoroolefins of formula (ii) are listed in Table 2.

The first refrigerant of the present invention may comprise a single compound of formula (i) or formula (ii), for example one of the compounds of Table 1 or Table 2, or a compound of formula (i) or formula (ii) Combinations thereof.

In another embodiment, the first refrigerant is selected from fluoroolefins including the compounds listed in Table 3.

The compounds listed in Tables 2 and 3 are commercially available or can be prepared by processes known in the art or as described herein.

1,1,1,4,4-pentafluoro-2-butene is solid KOH from vapor at room temperature from 1,1,1,2,4,4-hexafluorobutane (CHF ₂ CH ₂ CHFCF ₃ ) It can be prepared by dehydrofluorination using. The synthesis of 1,1,1,2,4,4-hexafluorobutane is described in US Pat. No. 6,066,768. 1,1,1,4,4,4-hexafluoro-2-butene was obtained from 1,1,1,4,4,4-hexafluoro- _2- iodobutane (CF ₃ CHICH ₂ CF ₃ ) , By reaction with KOH using a phase transfer catalyst at about 60 ° C. Synthesis of 1,1,1,4,4,4-hexafluoro-2-iodobutane was performed with perfluoromethyl iodide (CF ₃ I) and 3, at about 200 ° C. under autogenous pressure for about 8 hours. It can be carried out by the reaction of 3,3-trifluoropropene (CF ₃ CH = CH ₂ ).

3,4,4,5,5,5-hexafluoro-2-pentene can be prepared using 1,1,1,2,2,3,3-hepta using a carbon catalyst at 200 to 300 ° C. or using solid KOH. It may be prepared by dehydrofluorination of fluoropentane (CF ₃ CF ₂ CF ₂ CH ₂ CH ₃ ). 1,1,1,2,2,3,3-heptafluoropentane is 3,3,4,4,5,5,5-heptafluoro-1-pentene (CF ₃ CF ₂ CF ₂ CH = CH ₂ ) by hydrogenation.

1,1,1,2,3,4-hexafluoro-2-butene was prepared using 1,1,1,2,3,3,4-heptafluorobutane (CH ₂ FCF ₂ CHFCF ₃ using solid KOH). Dehydrofluorination).

1,1,1,2,4,4-hexafluoro-2-butene was converted to 1,1,1,2,2,4,4-heptafluorobutane (CHF ₂ CH ₂ CF ₂ using solid KOH). By dehydrofluorination of CF ₃ ).

1,1,1,3,4,4-hexafluoro2-butene was converted to 1,1,1,3,3,4,4-heptafluorobutane (CF ₃ CH ₂ CF ₂ CHF using solid KOH). ₂ ) by dehydrofluorination.

1,1,1,2,4-pentafluoro-2-butene was converted to 1,1,1,2,2,3-hexafluorobutane (CH ₂ FCH ₂ CF ₂ CF ₃ ) using solid KOH. It may be prepared by dehydrofluorination.

1,1,1,3,4-pentafluoro-2-butene was converted to 1,1,1,1,3,3,4-hexafluorobutane (CF ₃ CH ₂ CF ₂ CH ₂ F) using solid KOH. It can be prepared by the dehydrofluorination of.

1,1,1,3-tetrafluoro-2-butene is prepared by reacting 1,1,1,3,3-pentafluorobutane (CF ₃ CH ₂ CF ₂ CH ₃ ) with aqueous KOH at 120 ° C. Can be.

1,1,1,4,4,5,5,5-octafluoro-2-pentene was reacted with KOH from (CF ₃ CHICH ₂ CF ₂ CF ₃ ) using a phase transfer catalyst at about 60 ° C. Can be prepared by Synthesis of 4-iodo-1,1,1,2,2,5,5,5-octafluoropentane was performed using perfluoroethyl iodide (CF ₃ CF at about 200 ° C. under autogenous pressure for about 8 hours. It can be carried out by the reaction of ₂ I) with 3,3,3-trifluoropropene.

1,1,1,2,2,5,5,6,6,6-decafluoro-3-hexene has 1,1,1,2,2,5,5,6,6,6-decafluoro From rho- _3- iodohexane (CF ₃ CF ₂ CHICH ₂ CF ₂ CF ₃ ), can be prepared by reaction with KOH at about 60 ° C. using a phase transfer catalyst. Synthesis of 1,1,1,2,2,5,5,6,6,6-decafluoro-3-iodohexane was performed with perfluoroethyl iodide at about 200 ° C. under autogenous pressure for about 8 hours. It can be carried out by the reaction of (CF ₃ CF ₂ I) and 3,3,4,4,4-pentafluoro-1-butene (CF ₃ CF ₂ CH = CH ₂ ).

1,1,1,4,5,5,5-heptafluoro-4- (trifluoromethyl) -2-pentene is prepared using 1,1,1,2,5,5, It can be prepared by dehydrofluorination of 5-heptafluoro-4-iodo-2- (trifluoromethyl) -pentane (CF ₃ CHICH ₂ CF (CF ₃ ) ₂ ). _{CF 3 CHICH 2 CF (CF 3} ) 2 is prepared at a high temperature such as about 200 ℃ (CF _{3) 2} from the reaction of CFI and CF ₃ CH = CH _2.

1,1,1,4,4,5,5,6,6,6-decafluoro-2-hexene is 1,1,1,4,4,4-hexafluoro-2-butene (CF ₃ CH = CHCF ₃ ) may be prepared by reacting with tetrafluoroethylene (CF ₂ = CF ₂ ) and antimony pentafluoride (SbF ₅ ).

2,3,3,4,4-pentafluoro-1-butene is dehydrofluorinated of 1,1,2,2,3,3-hexafluorobutane using fluorided alumina at elevated temperature It can be prepared by.

2,3,3,4,4,5,5,5-octafluoro-1-pentene is a 2,2,3,3,4,4,5,5,5-nonnafluoro using solid KOH It may be prepared by dehydrofluorination of pentane.

1,2,3,3,4,4,5,5-octafluoro-1-pentene is a 2,2,3,3,4,4,5,5,5-nonna using alumina fluoride at elevated temperature It may be prepared by dehydrofluorination of fluoropentane.

Many of the compounds of Formula 1, Formula 2, Table 1, Table 2, and Table 3 exist as different configurational isomers or stereoisomers. If a particular isomer is not specified, the present invention is intended to include all single configurational isomers, single stereoisomers, or any combination thereof. For example, F11E is intended to represent E-isomers, Z-isomers, or any combination or mixture of two isomers in any ratio. As another example, HFO-1225ye is intended to represent E-isomers, Z-isomers, or any combination or mixture of two isomers in any ratio.

Additionally, the first refrigerant may be any of the single fluoroolefins of Formula (i), Formula (ii), Table 1, Table 2, and Table 3, or may be Formula (i), Formula (ii), Table It can be any combination of several fluoroolefins from 1, Table 2 and Table 3.

In some embodiments, the first refrigerant comprises a single fluoroolefin or a plurality of fluoroolefins selected from Formula (i), Formula (ii), Table 1, Table 2, and Table 3, hydrofluorocarbon, fluoro At least selected from ethers, hydrocarbons, CF ₃ I, ammonia (NH ₃ ), carbon dioxide (CO ₂ ), nitrous oxide (N ₂ O), and mixtures thereof, meaning mixtures of any of the foregoing compounds It can be any combination of one additional refrigerant.

In some embodiments, the first refrigerant may comprise a hydrofluorocarbon comprising at least one saturated compound comprising carbon, hydrogen and fluorine. Hydrofluorocarbons having 1 to 7 carbon atoms and a standard boiling point of about -90 ° C to about 80 ° C are particularly useful. Hydrofluorocarbons are commercially available from several sources or can be prepared by methods known in the art. Representative hydrofluorocarbon compounds include fluoromethane (CH ₃ F, HFC-41), difluoromethane (CH ₂ F ₂ , HFC-32), trifluoromethane (CHF ₃ , HFC-23), pentafluoro Loethane (CF ₃ CHF ₂ , HFC-125), 1,1,2,2-tetrafluoroethane (CHF ₂ CHF ₂ , HFC-134), 1,1,1,2-tetrafluoroethane (CF ₃ CH ₂ F, HFC-134a), 1,1,1-trifluoroethane (CF ₃ CH ₃ , HFC-143a), 1,1-difluoroethane (CHF ₂ CH ₃ , HFC-152a), Fluoroethane (CH ₃ CH ₂ F, HFC-161), 1,1,1,2,2,3,3-heptafluoropropane (CF ₃ CF ₂ CHF ₂ , HFC-227ca), 1,1, 1,2,3,3,3-heptafluoropropane (CF ₃ CHFCF ₃ , HFC-227ea), 1,1,2,2,3,3, -hexafluoropropane (CHF ₂ CF ₂ CHF ₂ , HFC-236ca), 1,1,1,2,2,3-hexafluoropropane (CF ₃ CF ₃ CH ₂ F, HFC-236cb), 1,1,1,2,3,3-hexafluoro Propane (CF ₃ CHFCHF ₂ , HFC-236ea), 1,1,1,3,3,3-hexafluoropropane (CF ₃ CH ₂ CF ₃ , HFC-236fa), 1,1,2,2,3 Pentafluoropropane (CHF ₂ CF ₂ CH ₂ F, HFC-245ca), 1,1,1 , 2,2-pentafluoropropane (CF ₃ CF ₂ CH ₃ , HFC-245cb), 1,1,2,3,3-pentafluoropropane (CHF ₂ CHFCHF ₂ , HFC-245ea), 1,1 , 1,2,3-pentafluoropropane (CF ₃ CHFCH ₂ F, HFC-245eb), 1,1,1,3,3-pentafluoropropane (CF ₃ CH ₂ CHF ₂ , HFC-245fa), 1,2,2,3-tetrafluoropropane (CH ₂ FCF ₂ CH ₂ F, HFC-254ca), 1,1,2,2-tetrafluoropropane (CHF ₂ CF ₂ CH ₃ , HFC-254cb) , 1,1,2,3-tetrafluoropropane (CHF ₂ CHFCH ₂ F, HFC-254ea), 1,1,1,2-tetrafluoropropane (CF ₃ CHFCH ₃ , HFC-254eb), 1, 1,3,3-tetrafluoropropane (CHF ₂ CH ₂ CHF ₂ , HFC-254fa), 1,1,1,3-tetrafluoropropane (CF ₃ CH ₂ CH ₂ F, HFC-254fb), 1 , 1,1-trifluoropropane (CF ₃ CH ₂ CH ₃ , HFC-263fb), 2,2-difluoropropane (CH ₃ CF ₂ CH ₃ , HFC-272ca), 1,2-difluoro Propane (CH ₂ FCHFCH ₃ , HFC-272ea), 1,3-difluoropropane (CH ₂ FCH ₂ CH ₂ F, HFC-272fa), 1,1-difluoropropane (CHF ₂ CH ₂ CH ₃ , HFC-272fb), 2-fluoro Propane _{(CH 3 CHFCH 3, HFC-} 281ea), propane, 1-fluoro _{(CH 2 FCH 2 CH 3,} HFC-281fa), a 1,1,2,2,3,3,4,4- octafluoro-butane (CHF ₂ CF ₂ CF ₂ CHF ₂ , HFC-338pcc), 1,1,1,2,2,4,4,4-octafluorobutane (CF ₃ CH ₂ CF ₂ CF ₃ , HFC-338mf), 1,1,1,3,3-pentafluorobutane (CF ₃ CH ₂ CHF ₂ , HFC-365mfc), 1,1,1,2,3,4,4,5,5,5-decafluoro Pentane (CF ₃ CHFCHFCF ₂ CF ₃ , HFC-43-10mee), and 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoroheptane (CF ₃ CF ₂ CHFCHFCF ₂ CF ₂ CF ₃ , HFC-63-14mee), but is not limited thereto.

In some embodiments, the first refrigerant may further comprise a fluoroether. Fluoroethers include at least one compound having carbon, fluorine, oxygen and optionally hydrogen, chlorine, bromine or iodine. Fluoroethers are commercially available or can be prepared by methods known in the art. Representative fluoroethers include nonafluoromethoxybutane (C ₄ F ₉ OCH ₃ , any or all possible isomers or mixtures thereof); Nonafluoroethoxybutane (C ₄ F ₉ OC ₂ H ₅ , any or all possible isomers or mixtures thereof); 2-difluoromethoxy-1,1,1,2-tetrafluoroethane (HFOC-236eaEβγ, or CHF ₂ OCHFCF ₃ ); 1,1-difluoro-2-methoxyethane (HFOC-272fbEβγ, CH ₃ OCH ₂ CHF ₂ ); 1,1,1,3,3,3-hexafluoro-2- (fluoromethoxy) propane (HFOC-347mmzEβγ, or CH ₂ FOCH (CF ₃ ) ₂ ); 1,1,1,3,3,3-hexafluoro-2-methoxypropane (HFOC-356mmzEβγ, or CH ₃ OCH (CH ₃ ) ₂ ); 1,1,1,2,2-pentafluoro-3-methoxypropane (HFOC-365mcEγδ, or CF ₃ CF ₂ CH ₂ OCH ₃ ); 2-ethoxy-1,1,1,2,3,3,3-heptafluoropropane (HFOC-467mmyEβγ, or CH ₃ CH ₂ OCF (CF ₃ ) ₂ ; and mixtures thereof, including but not limited to Do not.

In some embodiments, the first refrigerant may further comprise at least one hydrocarbon. Hydrocarbons are compounds having only carbon and hydrogen. Particularly useful are compounds having 3 to 7 carbon atoms. Hydrocarbons are available from a number of chemical suppliers. Representative hydrocarbons include propane, n-butane, isobutane, cyclobutane, n-pentane, 2-methylbutane, 2,2-dimethylpropane, cyclopentane, n-hexane, 2-methylpentane, 2,2-dimethyl Butane, 2,3-dimethylbutane, 3-methylpentane, cyclohexane, n-heptane, cycloheptane, and mixtures thereof, including but not limited to. In some embodiments, the disclosed compositions can include hydrocarbons containing heteroatoms, such as dimethylether (DME, CH ₃ OCH ₃ ). DME is available for purchase.

In some embodiments, the first refrigerant may further comprise carbon dioxide (CO ₂ ), which may be purchased from various sources or prepared by methods known in the art.

In some embodiments, the first refrigerant may further comprise ammonia (NH ₃ ), which may be purchased from various sources or prepared by methods known in the art.

In some embodiments, the first refrigerant may further comprise iodotrifluoromethane (CF ₃ I), which may be purchased from various sources or prepared by methods known in the art.

In certain embodiments, the first and second refrigerants can be as shown in Table 4 below.

In certain embodiments, the second refrigerant may consist essentially of HFO-1234yf. In another embodiment, the second refrigerant may comprise HFO-1234yf and R134a. In yet another embodiment, the second refrigerant may comprise HFO-1234yf and R32, or trans HFO-1234ze and HFC-32, or trans HFO-1234ze and HFC-134a, or trans HFO-1234ze and HFC-125 It may include.

In embodiments where the second refrigerant consists essentially of HFO-1234yf, the first refrigerant may comprise carbon dioxide (CO ₂ ) or nitrous oxide (N ₂ O). Alternatively, in embodiments where the second refrigerant consists essentially of HFO-1234yf, the first refrigerant may comprise HFO-1234yf and HFC-32. In another embodiment, where the second refrigerant consists essentially of HFO-1234yf, the first refrigerant may comprise trans HFO-1234ze and HFC-32.

In embodiments in which the second refrigerant comprises HFO-1234yf and HFC-134a, or in which the second refrigerant comprises HFO-1234yf and HFC-32, the first refrigerant may comprise either carbon dioxide or nitrous oxide. Alternatively, in embodiments where the second refrigerant comprises HFO-1234yf and HFC-134a, or HFO-1234yf and HFC-32, the first refrigerant may comprise HFO-1234yf and HFC-32. In other embodiments in which the second refrigerant comprises HFO-1234yf and HFC-134a, or HFO-1234yf and HFC-32, the first refrigerant may comprise trans HFO-1234ze and HFC-32.

In certain embodiments in which the second refrigerant comprises HFO-1234yf and R134a, and the first refrigerant comprises HFO-1234yf and HFC-32, the second refrigerant is 1 to 99% HFO-1234yf and 99 to 1% HFC-134a. In one embodiment, the second refrigerant comprises 1-53.1% HFO-1234yf and 46.9-99% HFC-134a. In particular, the second refrigerant comprises 53% HFO-1234yf and 47% HFC-134a. In one embodiment, the second refrigerant comprises 1-59% HFO-1234yf and 41-99% HFC-134a. In this embodiment, the second refrigerant is nonflammable at 100 ° C or 60 ° C. Such compositions are nonflammable and have a maximum dose in the range of 40-59% 1234yf and 41-60% 134a. In particular, the second refrigerant may comprise 53% HFO-1234yf and 47% HFC-134a.

In certain embodiments in which the second refrigerant comprises HFO-1234yf and HFC-32, the range of these components may be 1 to 99% HFO-1234yf and 99 to 1% HFC-32. In certain embodiments, the second refrigerant may comprise 20 to 99% HFO-1234yf and 80 to 99% HFC-32. More specifically, the second refrigerant may comprise 50 to 99% HFO-1234yf and 50 to 99% HFC-32, and even more specifically, the second refrigerant may be 63% HFO-1234yf and 37% HFC. It can include -32. In this embodiment, the second refrigerant can be used as a replacement for R404A. In another embodiment, the second refrigerant may comprise 27.5% HFO-1234yf and 72.5% HFC-32. In this embodiment, the second refrigerant can be used as a replacement for R410A. In any of the foregoing embodiments, wherein the second refrigerant comprises a specific range of HFO-1234yf and HFC-32, the first refrigerant is either CO ₂ or N ₂ O, HFO-1234yf / HFC-32 Blends of trans, or trans HFO-1234ze / HFC-32.

In embodiments wherein the second refrigerant comprises trans HFO-1234ze and HFC-32, the first refrigerant may comprise either carbon dioxide or nitrous oxide. Alternatively, in embodiments in which the second refrigerant comprises trans-HFO-1234ze and HFC-32, the first refrigerant may comprise HFO-1234yf and HFC-32. In other embodiments in which the second refrigerant comprises trans-HFO-1234ze and HFC-32, the first refrigerant may comprise trans HFO-1234ze and HFC-32.

In certain embodiments in which the second refrigerant comprises trans HFO-1234ze and HFC-32, the second refrigerant comprises 1-99% HFO-1234ze and 99-1% HFC-32. 1234ze may be either trans-1234ze or cis-1234ze. In any of the foregoing embodiments, wherein the second refrigerant comprises a specific range of trans HFO-1234ze and HFC-32, the first refrigerant is either CO ₂ or N ₂ O, HFO-1234yf / HFC-. Blends of 32, or blends of trans HFO-1234ze / HFC-32.

In embodiments wherein the second refrigerant comprises trans HFO-1234ze and HFC-134a, the first refrigerant may comprise either CO ₂ or N ₂ O. Alternatively, in embodiments where the second refrigerant comprises trans-HFO-1234ze and HFC-134a, the first refrigerant may comprise HFO-1234yf and HFC-32. In other embodiments in which the second refrigerant comprises trans-HFO-1234ze and HFC-134a, the first refrigerant may comprise trans HFO-1234ze and HFC-32.

In embodiments in which the second refrigerant comprises trans HFO-1234ze and HFC-125, the first refrigerant may comprise either carbon dioxide or nitrous oxide. Alternatively, in embodiments in which the second refrigerant comprises trans-HFO-1234ze and HFC-125, the first refrigerant may comprise HFC-32 and HFO-1234yf. In other embodiments in which the second refrigerant comprises trans-HFO-1234ze and HFC-125, the first refrigerant may comprise trans HFO-1234ze and HFC-32.

Cascade systems of various configurations are also within the scope of the present invention. For example, reference is made to FIG. 2, which shows a cascade system according to the present invention, in which elements corresponding to those shown in FIG. 1 are denoted by similar reference numerals and prime marks (′). The elements of FIG. 2 that correspond to the elements shown in FIG. 1 all operate as described above with respect to FIG. 1. The cascade system of FIG. 2 also includes a secondary heat transfer loop that includes a secondary fluid chiller 30 and a secondary fluid heat exchanger 32. The secondary fluid heat exchanger is located near the object to be cooled, such as food in the mesophilic display case. The secondary chiller cools the secondary heat transfer fluid. The use of the secondary heat transfer loop of the embodiment of FIG. 2 is advantageous because the secondary heat transfer loop must be spaced apart from one another at the same time, limiting the amount of refrigerant that must be used and the length of piping that the refrigerant must pass through and circulate. This is because heat is transferred between locations that are located (eg, spaced locations in a hypermarket). Minimizing the amount of refrigerant and the length of the refrigerant piping reduces refrigerant cost, leak rate, and mitigates the risks associated with using flammable and / or toxic refrigerants. In addition to, or alternatively to, the configuration as shown in FIG. 2, the secondary loop transfers heat from the cold display case to the cold loop of a configuration similar to that shown in FIG. 2 instead of the high or medium temperature loop. Can be used. However, the choice of secondary heat transfer fluid will be very limited because the viscosity of the liquid and the associated pumping costs increase at low temperatures.

The cascade refrigeration system of FIG. 2 also includes a cascade heat exchanger system disposed between the low temperature refrigeration loop and the medium temperature refrigeration loop. As in the above embodiment, the cascade heat exchanger system has a first inlet 22a 'and a first outlet 22b', where the first refrigerant vapor circulates from the first inlet to the first outlet and the heat exchanger system Condensation within to form a first refrigerant liquid, releasing heat. The cascade heat exchanger system also includes a second inlet 22c 'and a second outlet 22d', where the second refrigerant liquid circulates from the second inlet to the second outlet and the first refrigerant as described below. Absorbs the heat released by the second refrigerant vapor. Thus, in the embodiment of FIG. 2, heat released by the first refrigerant is directly absorbed by the second refrigerant.

Specifically, referring to FIG. 2, the secondary heat transfer fluid enters the secondary chiller at the first inlet 30a and exits the secondary chiller at the first outlet 30b. Secondary heat transfer fluids may include ethylene glycol, propylene glycol, carbon dioxide, water brine or any of several other fluids or slurries known in the art. In some embodiments, the secondary heat transfer fluid can undergo a phase change. The secondary chiller also includes a second inlet 30c and a second outlet 30d. The second refrigerant enters the secondary fluid chiller through the second inlet 30c and evaporates, allowing the heat transfer fluid in the chiller to cool. The cooled heat transfer fluid exits the chiller 30 through the first outlet 30b and circulates to a secondary fluid heat exchanger 32 located near the object to be cooled. This object to be cooled may be food inside a frozen display case of a supermarket. The heat transfer fluid is warmed by this object and returns to the secondary fluid chiller, where it is cooled again by evaporation of the secondary refrigerant that also circulates through the secondary fluid chiller. A liquid pump (not shown) pumps the heat transfer fluid from the secondary fluid heat exchanger back to the secondary fluid chiller. This warmed heat transfer fluid causes the second refrigerant to evaporate in the secondary fluid chiller. In order to control the flow rate and pressure through the cascade heat exchanger and the secondary fluid chiller, respectively, a separate expansion device (not shown) enters the inlet line and the secondary fluid chiller 30 entering the cascade heat exchanger 22 '. May be placed in the inlet line. Although cascade heat exchanger 22 ′ and secondary fluid chiller 30 are shown as being connected in parallel, they may alternatively be connected in series without departing from the scope of the present invention.

A portion of the reduced pressure and temperature of the second refrigerant liquid exiting the condenser 26 'enters the cascade heat exchanger 22' at the inlet 22c '. In the cascade heat exchanger 22 ', as in the first embodiment of FIG. 1, the first refrigerant condenses and the second refrigerant evaporates and exits the heat exchanger 22' at the outlet 22d '. The second refrigerant exiting the secondary fluid chiller 30 at the second outlet 30d merges with the second refrigerant from the outlet 22d 'of the cascade heat exchanger and circulates to the second compressor 24'. The cycle through the warm loop 14 'and the cold loop 12' is otherwise the same as discussed above with respect to FIG.

Another embodiment of the cascade refrigeration system of the present invention is shown in FIG. 3. In the embodiment of Fig. 3, elements corresponding to the elements shown in Fig. 1 are denoted by similar reference numerals and double prime marks ("). Operate as described above with reference to Fig. 3. The system of Fig. 3 is shown schematically at 40 for two cascade heat exchangers instead of one cascade heat exchanger as shown in the embodiment of Figs. As in the embodiment of Figure 2, the use of the secondary heat transfer loop of the embodiment of Figure 3 is advantageous, because the amount and amount of refrigerant to which the secondary heat transfer loop should be used is advantageous. This limits the length of the pipe that must pass and circulate, while at the same time transferring heat between the locations that must be spaced apart from each other.

The embodiment of FIG. 3 includes a cascade heat exchanger system comprising two cascade heat exchangers connected to each other via a secondary heat transfer loop. The cascade heat exchanger system of FIG. 3 has a first inlet 42a and a first outlet 42b, where the first refrigerant vapor circulates from the first inlet to the first outlet and condenses within the cascade heat exchanger system to form a first It forms a refrigerant liquid and releases heat. The cascade heat exchanger system also includes a second inlet 44c and a second outlet 44d, where the second refrigerant liquid circulates from the second inlet to the second outlet and indirectly dissipates heat released by the first refrigerant. Absorption to form a second refrigerant vapor. In the embodiment of FIG. 3, the second refrigerant liquid indirectly absorbs heat released by the first refrigerant through the secondary heat transfer fluid, that is, as described below, the first refrigerant is heat transfer to the heat transfer fluid. And heat transfer fluid circulates to the second cascade heat exchanger 44 where heat transfer fluid transfers heat from the first refrigerant to the second refrigerant. This heat is released to the environment.

Referring to FIG. 3, the cascade refrigeration system 10 "has a cold loop 12" having a first inlet 42a and a first outlet 42b, and a second inlet 42c and a second outlet 42d. A first cascade heat exchanger (42). The mesophilic loop 14 "includes a second cascade heat exchanger 44 having a first inlet 44a and a first outlet 44b and a second inlet 44c and a second outlet 44d. The first refrigerant vapor circulated from the outlet 20b ″ of the first compressor as shown in FIG. 3 to the first inlet 42a of the first heat exchanger 42. As in the embodiment shown in FIG. 1, this compressed refrigerant vapor is condensed in the first cascade heat exchanger to form a first refrigerant liquid, releasing heat. The first refrigerant liquid then circulates to the first outlet 42b of the first cascade heat exchanger. The heat transfer fluid circulates in the secondary heat transfer loop between the second cascade heat exchanger 44 and the first cascade heat exchanger, which is also part of the mesophilic loop 14 ". Specifically, the heat transfer fluid is in the second inlet 42c. Enters the first heat exchanger 42 and exits the first heat exchanger through the second outlet 42d. This heat transfer fluid is heat released by the condensing first refrigerant entering the heat exchanger through the inlet 42a. The warmed heat transfer fluid exits the first heat exchanger through the second outlet 42d and circulates to the second heat exchanger 44. The heat transfer fluid passes from the second inlet 44c to the second. The second refrigerant is cooled in the second heat exchanger by releasing heat to the second refrigerant entering the heat exchanger and exiting the second heat exchanger at the second outlet 44d. The second cascade heat exchanger is warmed by the heat transfer fluid. Evaporates within to form a second refrigerant vapor. The cooled heat transfer fluid exits the first outlet 44b of the second heat exchanger. The cycle through the low temperature loop 12 "and the middle temperature loop 14" Otherwise, in this embodiment is the same as discussed above with respect to FIG. 1, except that the first and / or second refrigerant may be fluoroolefins but need not necessarily be fluoroolefins.

A further embodiment of the cascade refrigeration system of the present invention is shown in FIG. 4. In the embodiment of FIG. 4, elements corresponding to those shown in FIG. 1 are denoted by similar reference numerals and triple prime symbols ('' '). The elements of FIG. 4 that correspond to the elements shown in FIG. 1 all operate as described above with respect to FIG. 1. The system of FIG. 4 includes two cold loops, a loop 12A similar to the cold loop 12 of FIG. 1, and a loop 12B. One of the two cold loops, for example loop 12B, provides refrigeration at a temperature that is different from, for example, a temperature at which refrigeration is provided by the other cold loop and a temperature at which refrigeration is provided by the mid-temperature loop. . The advantage of such a system is that the refrigerant in the cold loop can be used to cool two different objects, for example two separate freezer display cases, to two different temperatures.

In the embodiment of FIG. 4, a cascade heat exchanger system is disposed between two loops. The cascade heat exchanger system has a first inlet 22a '' 'and a second inlet 22b' '' and a first outlet 52, where the first refrigerant vapor is first from the first inlet and the second inlet. It circulates to the outlet and condenses in the heat exchanger system to form a first refrigerant liquid, releasing heat. The cascade heat exchanger system also includes a third inlet 22c '' 'and a second outlet 22d' '', where the second refrigerant liquid circulates from the third inlet to the second outlet and by the first refrigerant The released heat is absorbed to form a second refrigerant vapor. Thus, in the embodiment of FIG. 4, the heat released by the first refrigerant is directly absorbed by the second refrigerant and it is released to the surroundings.

It should be noted that it is within the scope of the present invention that the embodiment of FIG. 4 includes all cascade heat exchanger systems that transfer heat in the manner described above.

In the system of the embodiment of FIG. 4, the flow of the first refrigerant liquid is split at or after exiting the cascade heat exchanger 22 ′ ″ at 52. One portion circulates through one cold loop 12A and the other circulates through another cold loop 12B. The portion of the first refrigerant circulating through the loop 12B enters the further expansion device 54 at the inlet 54a and the pressure and temperature of this portion of the first refrigerant liquid are reduced. This reduced pressure and temperature of the liquid refrigerant then circulates through the outlet 54b of the further expansion device and then to the further evaporator 56. It should be noted that this liquid may be partially vaporized during this expansion. The further evaporator 56 includes an inlet 56a and an outlet 56b. Refrigerant liquid from the further expansion device enters the evaporator through evaporator inlet 56a and evaporates within the evaporator to form refrigerant vapor, creating cooling and circulating to outlet 56b. Cold loop 12B also includes an additional compressor 58 having an inlet 58a and an outlet 58b. The first refrigerant vapor from the additional evaporator 56 circulates and compresses to the inlet 58a of the additional compressor 58 to increase the pressure and temperature of the first refrigerant vapor, and the compressed first refrigerant vapor of the additional compressor It circulates to the outlet 58b and to the inlet 22b '' 'of the cascade heat exchanger 22' ''. The cycle through the other low temperature loop 12A and the medium temperature loop 14 '' 'would otherwise be the same as discussed above with respect to FIG. In particular, the cold loop 12A also includes an evaporator 18 '' 'that can be housed inside the freezer display case, and an additional evaporator 56 can be housed inside the freezer display case. This system can thereby provide cooling to two separate freezer display cases.

According to the present invention, there is also provided a method comprising: (a) absorbing heat from an object to be cooled in a first refrigeration loop and dissipating this heat to a second refrigeration loop; And (b) absorbing heat from the first refrigeration loop in the second refrigeration loop and dissipating this heat to the surroundings. The refrigerant in either loop, that is, the loop where heat is absorbed or the loop where heat is released, or both, can comprise fluoroolefins. Heat from the first refrigerant loop may be absorbed directly in the second refrigeration loop as in the embodiments of FIGS. 1, 2 and 4, or may be absorbed directly in the second refrigeration loop as in the embodiment of FIG. 3. have.

[Example]

Example  One

Cooling performance of the upper temperature circuit of the cascade system

Table 5 shows the performance of some exemplary compositions compared to HFC-134a. In Table 5, Evap Pres is the evaporator pressure, Cond Pres is the condenser pressure, Comp Disch T is the compressor discharge temperature, COP is the coefficient of performance (similar to energy efficiency), CAP is the capacity, and Avg. Temp. glide is the average value of the temperature glide in the evaporator and condenser, and GWP is the global warming index. The data is based on the following conditions.

Evaporator Temperature-10 ℃

Condenser temperature 40.0 ℃

Subcool amount 6 ℃

Return gas temperature 10 ℃

Compressor efficiency 70%

Note that evaporator overheat enthalpy is not included in the cooling capacity and energy efficiency measurements.

The data in Table 5 shows that the 1234yf / 134a composition is very comparable to 134a in terms of COP, capacity, pressure and temperature of the system, with lower GWP values. In addition, all compositions have a low temperature gradient and specific compositions can be selected based on regulatory requirements for GWP that are not currently determined. Compositions comprising 53 wt.% HFO-1234yf and 47 wt. This is shown graphically in FIG. 5.

Example  2

HFO -1234 yf Of HFC -134a flammability of the mixture

Flammable compositions can be identified by testing under the American Society of Testing and Materials ASTM E681-2004 as an electronic ignition source. 101 인지 (14.7) for compositions comprising HFO-1234yf and HFC-134a to determine if flammable and, in such cases, to find the lower flammability limit (LFL) and the upper flammability limit (UFL). psia), 50% relative humidity, and at about 23 ° C. (room temperature), 60 ° C. and 100 ° C. such flammability tests were performed. The results are provided in Table 6.

At room temperature conditions (about 23 ° C.), a composition with up to 66.25% by weight of HFO-1234yf in HFC-134a will be considered nonflammable. At 60 ° C., a composition with up to 60.00% by weight of HFO-1234yf in HFC-134a will be considered nonflammable. At 100 ° C., compositions comprising up to 53.10 wt.% HFO-1234yf in HFC-134a will be considered nonflammable.

Example  3

Cooling performance for low temperature circuits in cascade systems

Table 7 shows ASHRAE names for mixtures comprising CO ₂ , R404A (HFC-125, HFC-134a, and HFC-143a), R410A (ASHRAE names for mixtures comprising HFC-32 and HFC-125) and HFC. The performance of certain compositions compared to -32 is shown. In Table 7, Evap Pres is the evaporator pressure, Cond Pres is the condenser pressure, Comp Disch T is the compressor discharge temperature, COP is the coefficient of performance (similar to energy efficiency), CAP is the capacity, Avg. Temp. glide is the average of the temperature gradients in the evaporator and condenser, and GWP is the global warming index. The data is based on the following conditions.

Evaporator Temperature-35 ℃

Condenser Temperature-6 ℃

Subcool amount 0 ℃

Return Gas Temperature-25 ℃

Compressor efficiency 70%

Note that evaporator overheat enthalpy is not included in the cooling capacity and energy efficiency measurements.

Compositions comprising 63 wt% HFO-1234yf and 37 wt% HFC-32 actually show improved COP and capacity over R404A and also have significantly lower GWP. Compositions comprising 27.5 wt% HFO-1234yf and 72.5 wt% HFC-32 have a very low temperature gradient that is comparable to the COP and dose of R410A and exhibits azeotrope-like behavior. Has a significantly lower GWP.

Note that all compositions comprising a mixture of HFO-1234yf and HFC-32 have improved COP (energy efficiency) when compared to CO ₂ .

Example  4

Total equivalent warming index ( Total Equivalent Warming Impact )

The total equivalent warming index (TEWI) is measured for systems as disclosed herein as compared to conventional uncoupled supermarket refrigeration systems as well as conventional cascade systems. To quantify the more complete environmental impact of the use of different refrigerants, TEWI measures the leak rate as well as the impact of the energy efficiency of the system, the contribution from the energy sources used to power the equipment, and the amount of refrigerant charged into the system. Consider.

This embodiment is a conventional European direct expansion (DX), which traditionally uses R404A for both medium temperature (MT) and low temperature (LT) refrigeration systems as a baseline for comparison. Use a supermarket refrigeration system. Some assumptions made based on a typical European supermarket system are shown in Table 8. In addition, an estimated equipment life of 15 years was assumed and the CO ₂ emitted from electricity generation was estimated to be 0.616 kg CO ₂ / kilowatt hour (kw-hr).

Table 9 provides the conditions under which the system performance (COP, or coefficient of performance, measures of energy efficiency) was evaluated. In Table 9, temp is temperature, evap is the evaporator, cond is the condenser and comp is the compressor.

Table 10 lists the evaluated COP values as calculated based on the conditions described above in Table 9, as well as some different embodiments of the present invention compared to conventional uncoupled and cascaded systems where TEWI measurements were made. have.

TEWI values include indirect contributions, including energy sources and energy use, and direct contributions due to the release of refrigerant with a given GWP from the system. Table 11 lists the indirect and direct contribution and TEWI values calculated for the various systems described above, in order from maximum environmental impact to minimum environmental impact in terms of equivalent CO ₂ emissions (in millions of kg) over the life of the equipment. have.

The results in Table 11 show that TEWIs for unbound or cascade refrigeration systems using refrigerants known in the art to use HFO based refrigerants (eg, in the mesophilic loops of Cascade refrigeration system 3 and cascade refrigeration system 4) are known. Proving that it can result in a lower TEWI value than the value.

Claims (15)

A cascade refrigeration system having at least two refrigeration loops each circulating a refrigerant,
(a) A first expansion device for reducing the pressure and temperature of the first refrigerant liquid;
(b) An evaporator having an inlet and an outlet, wherein the first refrigerant liquid from the first expansion device enters the evaporator through the evaporator inlet and evaporates within the evaporator to form a first refrigerant vapor, thereby producing cooling and circulating to the outlet- ;
(c) a first compressor having an inlet and an outlet, wherein the first refrigerant vapor from the evaporator is circulated and compressed to the inlet of the first compressor, thereby increasing the pressure and temperature of the first refrigerant vapor and compressing the first refrigerant Steam circulates to the outlet of the first compressor;
(d) Cascade Heat Exchanger System-The Cascade Heat Exchanger System,
(i) a first inlet and a first outlet, wherein the first refrigerant vapor circulates from the first inlet to the first outlet and condenses in the heat exchanger system to form a first refrigerant liquid, thereby releasing heat; and
(ii) a second inlet and a second outlet, wherein the second refrigerant liquid circulates from the second inlet to the second outlet and absorbs the heat released by the first refrigerant to form a second refrigerant vapor; ;
(e) a second compressor having an inlet and an outlet, wherein the second refrigerant vapor from the cascade heat exchanger system is sucked into the compressor and compressed to increase the pressure and temperature of the second refrigerant vapor;
(f) a condenser having an inlet and an outlet for circulating the second refrigerant vapor and condensing the second refrigerant vapor from the compressor to form a second refrigerant liquid, wherein the second refrigerant liquid exits the condenser through the outlet -; And
(g) a second expansion device for reducing the pressure and temperature of the second refrigerant liquid exiting the condenser and entering the second inlet of the cascade heat exchanger system,
At least one of the first refrigerant and the second refrigerant comprises a fluoroolefin. The system of claim 1 wherein the second refrigerant comprises a fluoroolefin selected from the group consisting of HFO-1234yf, trans-1234ze and E-1234ze. The system of claim 1, wherein the second refrigerant consists essentially of HFO-1234yf. The system of claim 2, wherein the second refrigerant also comprises R134a. The system of claim 2, wherein the second refrigerant also comprises HFC-32. The system of claim 3 wherein the first refrigerant comprises a composition selected from the group consisting of carbon dioxide and nitrous oxide. The system of claim 3 wherein the first refrigerant comprises HFO-1234yf and HFC-32. The system of claim 4, wherein the first refrigerant comprises a composition selected from the group consisting of carbon dioxide and nitrous oxide. The system of claim 4 wherein the first refrigerant comprises HFO-1234yf and HFC-32. The system of claim 5, wherein the second refrigerant comprises HFO-1234yf. The system of claim 5, wherein the second refrigerant comprises trans-1234ze. The system of claim 5 wherein the first refrigerant comprises carbon dioxide or nitrous oxide. The system of claim 5 wherein the first refrigerant comprises HFO-1234yf and HFC-32. A cascade refrigeration system having at least two refrigeration loops each circulating a refrigerant,
(a) a first expansion device for reducing the pressure and temperature of the first refrigerant liquid;
(b) an evaporator having an inlet and an outlet, wherein the first refrigerant liquid from the first expansion device enters the evaporator through the evaporator inlet and evaporates within the evaporator to form a first refrigerant vapor, thereby producing cooling and exiting to the outlet Circulating-;
(c) a first compressor having an inlet and an outlet, wherein the first refrigerant vapor from the evaporator is circulated and compressed to the inlet of the first compressor, thereby increasing the pressure and temperature of the first refrigerant vapor and compressing the first refrigerant Steam circulates to the outlet of the first compressor;
(d) (i) a first cascade heat exchanger, said first cascade heat exchanger,
(A) First inlet and first outlet, wherein the first refrigerant vapor from the evaporator circulates from the first inlet to the first outlet and condenses in the first heat exchanger to form a first refrigerant liquid, thereby dissipating heat -, And
(B) second inlet and second outlet, wherein the heat transfer fluid circulates from the second inlet to the second outlet, and heat released by the first refrigerant vapor is absorbed by the heat transfer fluid when the first refrigerant vapor is condensed. -Has-W,
(ii) a second cascade heat exchanger—the second cascade heat exchanger,
(A) a first inlet and a first outlet, wherein the heat transfer fluid from the first cascade heat exchanger circulates from the first inlet to the first outlet and releases the heat absorbed within the first cascade heat exchanger; and
(B) a second inlet and a second outlet, wherein the second refrigerant liquid circulates from the second inlet to the second outlet and absorbs the heat released by the heat transfer fluid to form a second refrigerant vapor;
Cascade heat exchanger system comprising a;
(e) a second compressor having an inlet and an outlet, wherein the second refrigerant vapor from the second cascade heat exchanger is drawn into the compressor and compressed, thereby increasing the pressure and temperature of the second refrigerant vapor;
(f) a condenser having an inlet and an outlet for circulating the second refrigerant vapor and condensing the second refrigerant vapor from the compressor to form a second refrigerant liquid, wherein the second refrigerant liquid exits the condenser through the outlet -; And
(g) a second expansion device for reducing the pressure and temperature of the second refrigerant liquid exiting the condenser and entering the second inlet of the second cascade heat exchanger;
A system comprising a first refrigeration loop comprising a. A method of exchanging heat between at least two refrigeration loops,
(a) absorbing heat from the object to be cooled in the first freezing loop and dissipating this heat to the second freezing loop; And
(b) absorbing heat from the first freezing loop and dissipating this heat to the surroundings in a second freezing loop,
The refrigerant in at least one of the refrigeration loops comprises a fluoroolefin.

Images