JP2014514423A - Heat transfer composition and method - Google Patents

Abstract

(A) about 10 wt% to about 35 wt% HFC-32; (b) about 10 wt% to about 35 wt% HFC-125; (c) about 20 wt% to about 50 wt% HFO-1234ze. , HFO-1234yf, and combinations thereof; (d) from about 15 wt% to about 35 wt% HFC-134a; and optionally (e) up to about 10 wt% CF ₃ I, and up to about 5 wt% Compositions, methods and systems comprising or utilizing a multi-component mixture comprising HFCO-1233ze, wherein the weight percentages are based on the sum of components (a)-(e) in the composition.
[Selection figure] None

Description

  This application is related to and claims the benefit of US application 13 / 099,218 filed May 2, 2011 and US application 61 / 598,056 filed February 13, 2012, respectively. Each of the above-listed applications is hereby incorporated by reference in its entirety.

  The present invention provides compositions, methods, and systems that have utility in cooling applications, and that are particularly beneficial in medium and low temperature cooling applications, and in certain forms refrigerant HFC-404A for heating and cooling applications. It relates to refrigerant compositions for replacement and retrofitting medium temperature and low temperature cooling systems such as systems designed to be used with HFC-404A.

Mechanical cooling systems using refrigerant liquids and associated heat transfer devices such as heat pumps and air conditioners are well known in the art for industrial, commercial, and domestic use. Fluorocarbon-based fluids have found widespread use in many home, commercial, and industrial applications, such as working fluids in systems such as air conditioning, heat pumps, and cooling systems. Some of the environmental issues of concern, such as the relatively high global warming potential associated with the use of some of the compositions used so far in these applications, such as hydrofluorocarbons (HFCs) It is increasingly desirable to use fluids that have a low or even zero ozone depletion potential and global warming potential. For example, a number of governments have signed the Kyoto Protocol to protect the global environment, specifying a reduction in CO ₂ emissions (global warming). Thus, there is a need for low flammability or non-flammable, non-toxic alternatives to some high global warming HFCs.

  One important type of cooling system is known as a “cold cooling system”. Such a system is particularly important for the food manufacturing, distribution, and retail industries in that it plays a pivotal role in ensuring that the food that reaches the consumer is fresh and suitable for eating. In such a cryogenic cooling system, the refrigerant liquid normally used is HFC-404A (the combination of HFC-125: HFC-143a: HFC-134a in a weight ratio of approximately 44: 52: 4 is HFC-404A or R in the art). -Referred to as -404A). R-404A has a high calculated global warming potential (GWP) of 3922.

  Thus, there is an increasing need for new fluorocarbon and hydrofluorocarbon compounds and compositions that are attractive alternatives to the compositions previously used in these and other applications. For example, it has become desirable to retrofit chlorine-containing cooling systems by replacing chlorine-containing refrigerants with non-chlorine-containing refrigerant compounds that do not destroy the ozone layer, such as hydrofluorocarbons (HFCs). In general, the industry, especially the heat transfer industry, is continually searching for new fluorocarbon-based mixtures that provide alternatives to CFCs and HCFCs and are considered environmentally friendly substitutes for them. However, at least for heat transfer fluids, any potential surrogate, among others, such as excellent heat transfer properties, chemical stability, low toxicity or non-toxicity, non-flammability, and / or lubricant compatibility, It is generally considered important to have these properties that are also present in many of the most widely used fluids.

  Regarding usage efficiency, it should be noted that losses in refrigerant thermodynamic performance or energy efficiency may have secondary environmental impacts due to increased fossil fuel usage resulting from increased demand for electrical energy. is important.

  Further, it is generally believed that CFC refrigerant substitutes should be effective without significant design changes to the normal vapor compression technology currently used with CFC refrigerants.

  Flammability is another important property for many applications. That is, in many applications, particularly heat transfer applications, it is considered to be either important or essential to use a non-combustible composition. Thus, it is often beneficial to use compounds that are non-flammable in such compositions. As used herein, the term “nonflammable” refers to a compound or composition that is determined to be nonflammable as measured according to ASTM standard E-681 (2002), which is incorporated herein by reference. Point to. Unfortunately, many HFCs that may otherwise be desirable for use in refrigerant compositions are not non-flammable in the sense that the term is used herein. For example, the fluoroalkane difluoroethane (HFC-152a) and the fluoroalkene 1,1,1-trifluoropropene (HFO-1243zf) are each flammable and therefore cannot be used in many applications.

ASTM standard E-681 (2002)

  Thus, Applicants have identified heating and cooling systems and methods, particularly vapor compression heating and cooling systems, such as systems used and / or designed to be used with HFC-404A, and even more particularly low temperatures. We have recognized the need for highly advantageous compositions, particularly heat transfer compositions, in cooling systems.

Applicants have (a) about 10% to about 35% by weight difluoromethane (HFC-32); (b) about 10% to about 35% by weight pentafluoroethane (HFC-125); c) about 20% to about 50% by weight of HFO-1234ze, HFO-1234yf, and combinations thereof; (d) about 15% to about 35% by weight of 1,1,1,2-tetrafluoroethane ( HFC-134a); and optionally (e) up to about 10% by weight of CF ₃ I, and up to about 5% by weight of HFCO-1233ze, wherein the weight percent comprises components (a) to (e) in the composition It has been found that the above-described needs and other needs can be satisfied by compositions, methods, and systems that include or utilize multi-component mixtures that are based on the sum of the above.

In some preferred embodiments, the composition comprises (a) about 15 wt% to about 30 wt% HFC-32; (b) about 10 wt% to about 30 wt% HFC-125; (c) From about 20 wt% to about 50 wt% HFO-1234ze, HFO-1234yf, and combinations thereof; (d) from about 15 wt% to about 35 wt% HFC-134a; and optionally (e) about 5 wt% % Of CF ₃ I, and up to about 5% by weight of HFCO-1233ze, where% by weight comprises a multi-component mixture that is based on the sum of components (a)-(e) in the composition.

In a further aspect, the composition comprises (a) about 20% to about 30% by weight HFC-32; (b) about 20% to about 30% by weight HFC-125; (c) about 0%. % By weight (and / or more than 0% by weight) to about 15% by weight HFO-1234yf, and from about 10% to about 30% by weight HFO-1234ze; (d) from about 15% to about 30% by weight. HFC-134a; and optionally (e) not more than about 5% by weight of CF ₃ I, and not more than about 5% by weight of HFCO-1233ze, wherein the weight percent of components (a) to (e) in the composition Includes multi-component mixtures that are based on total.

  The present invention also provides methods and systems that utilize the compositions of the present invention, such as methods and systems for heat transfer and for retrofitting existing heat transfer systems. Some preferred method forms of the present invention relate to methods that provide relatively low temperature cooling, such as in cryogenic cooling systems. Another preferred method form of the present invention is a method of retrofitting an existing cooling system, preferably a cryogenic cooling system, designed and / or including R-404A refrigerant, such existing There is provided a method as described above comprising introducing the composition of the present invention into such a system without substantial design changes of the cooling system.

  The term HFO-1234ze is used herein to refer generically to 1,1,1,3-tetrafluoropropene, regardless of whether it is in the cis or trans form. The terms “cis-HFO-1234ze” and “trans-HFO-1234ze” are used herein to indicate the cis and trans forms of 1,1,1,3-tetrafluoropropene, respectively. Thus, the term “HFO-1234ze” includes within its scope cis-HFO-1234ze, trans-HFO-1234ze, and all combinations and mixtures thereof.

  The term “HFO-1233” is used herein to refer to all trifluoromonochloropropenes. Among the trifluoromonochloropropenes are 1,1,1-trifluoro-2-chloropropene (HFCO-1233xf), both cis and trans 1,1,1-trifluoro-3-chloropropene (HFCO- 1233zd). The term HFCO-1233zd is used herein generically to refer to 1,1,1-trifluoro-3-chloropropene, regardless of whether it is in the cis or trans form. The terms “cis-HFCO-1233zd” and “trans-HFCO-1233zd” are used to indicate the cis and trans forms of 1,1,1-trifluoro-3-chloropropene, respectively. Thus, the term “HFCO-1233zd” includes within its scope cis-HFCO-1233zd, trans-HFCO-1233zd, and all combinations and mixtures thereof.

[Means for solving problems]
Cold cooling systems are important in many applications such as food manufacturing, distribution, and retail industries. Such a system plays a vital role in ensuring that the food that reaches the consumer is fresh and suitable for eating. In such low temperature cooling systems, one commonly used refrigerant liquid is HFC-404A, which has a high calculated global warming potential (GWP) of 3922. Applicants have provided a composition of the invention that has a lower GWP value and provides a substantially non-flammable, non-toxic fluid that has a cooling capacity and / or efficiency comparable to HFC-404A in such systems. It has been found that the need for alternatives and / or substitutes for refrigerants in such applications, particularly and preferably HFC-404A, is satisfied in a special and unexpected manner.

  The present invention can also include intermediate cooling compositions, systems, and methods. According to some preferred embodiments, the method and system involve an evaporator temperature of greater than about -15 ° C to about 5 ° C. One example of such an intermediate temperature system and method involves providing cooling in the fresh food compartment of a home refrigerator.

Heat transfer composition:
The compositions of the present invention can generally be adapted for use in heat transfer applications, i.e. can be adapted as heating and / or cooling media, but as mentioned above, medium and low temperature cooling systems, And preferably is particularly well suited for use in cryogenic systems that previously used HFC-404A and / or systems that previously used R-22.

  Applicants have the advantage, but difficult to achieve, of using the components of the present invention within the broad and narrow ranges described herein in particular preferred systems and methods by the present compositions. Using these substantially the same but defined ranges of components that are important in achieving a combination of properties, one or more of the compositions, systems, or methods of the present invention It has been found that it can have a detrimental effect on important properties. A highly preferred combination of properties is achieved for a composition having a weight ratio of about 0.9: 1.2 to about 1.2: 0.9 HFC-32: HFC-125, in some embodiments A ratio of about 1: 1 is preferred. Applicants have also found that a highly preferred combination of properties is also from about 5: 1 to about 0.7: 1, more preferably from about 1: 1 to about 3: 1 HFO-1234ze: HFO-1234yf. It has been found that this is also achieved with compositions having a weight ratio. In some preferred embodiments, a ratio of about 4: 1 is preferred.

  For convenience purposes, the combination of HFO-1234ze and HFO-1234yf is referred to herein as a “tetrafluoropropene component” or “TFC”, and in some embodiments, is a highly preferred combination of properties. Combinations can be achieved for compositions comprising a weight ratio of HFC-134a: TFC of about 5: 7 to about 1: 1, with a ratio of about 4: 6 being preferred in some embodiments.

  Although it is contemplated that any isomer of HFO-1234ze can be used, Applicants have noted that in some embodiments HFO-1234ze comprises trans-HFO-1234ze, preferably trans-HFO-1234ze. Has been found to be substantially composed of trans-HFO-1234ze in some embodiments.

  As mentioned above, the Applicants have found that the composition of the present invention can achieve a combination of properties that are difficult to achieve, such as particularly low GWP. For purposes of a non-limiting example, Table A below shows the substantial improvement in GWP exhibited by some compositions of the present invention compared to the GFC of HFC-404A having a GWP of 3922.

  The compositions of the present invention may be used for the purpose of improving some functionality of the composition or imparting some functionality to the composition, or in some cases reducing the cost of the composition. May contain other ingredients. For example, refrigerant compositions according to the present invention, particularly those used in vapor compression systems, are generally in an amount of about 30 to about 50% by weight of the composition, and in some cases, optionally in an amount greater than about 50%, and Other cases contain as low as about 5% lubricant. Further, the composition can also include a compatibilizing agent such as propane for the purpose of promoting the compatibility and / or solubility of the lubricant. Such compatibilizers such as propane, butanes, and pentanes are preferably present in an amount of about 0.5 to about 5% by weight of the composition. As disclosed by US Pat. No. 6,516,837 (the disclosure of which is incorporated herein by reference), a combination of surfactant and solubilizer is added to the composition to improve oil solubility. It can also be promoted. Of polyol esters (POE) and polyalkylene glycols (PAG), PAG oils, silicone oils, mineral oils, alkylbenzenes (AB), and poly (α-olefins) (PAO) used in refrigeration machines using hydrofluorocarbon (HFC) refrigerants Such commonly used cooling lubricants can be used with the refrigerant composition of the present invention. Commercially available mineral oils include Witco LP 250 (R) from Witco, Zerol 300 (R) from Shrieve Chemical, Sunisco 3GS from Witco, and Calumet R015 from Calumet. Commercially available alkyl benzene lubricants include Zerol 150®. Commercially available esters include neopentyl glycol dipelargonate available as Emery 2917® and Hatcol 2370®. Other useful esters include phosphate esters, dibasic acid esters, and fluoroesters. In some cases, hydrocarbon-based oils are sufficiently soluble with refrigerants containing iodocarbon, and the combination of iodocarbon and hydrocarbon oil is more stable than other types of lubricants. there is a possibility. Such a combination may therefore be advantageous. Preferred lubricants include polyalkylene glycols and esters. Polyalkylene glycols are highly preferred in some embodiments because they are currently used in certain applications such as automotive air conditioning. Of course, different mixtures of different types of lubricants can be used.

Other additives not mentioned herein may be included by those skilled in the art in view of the teachings contained herein without departing from the novel basic features of the invention.
Heat transfer method and system:
Thus, the methods, systems, and compositions are generally suitable for use with a wide range of heat transfer systems, particularly cooling systems such as air conditioning (including both fixed and mobile air conditioning systems), cooling, heat pump systems, and the like. ing. In some preferred embodiments, the compositions of the present invention are used in cooling systems that are originally designed for use with HFC refrigerants such as R-404A. Preferred compositions of the present invention exhibit many of the desirable properties of R-404A, but have a significantly lower GWP than that of R-404A, while at the same time being substantially equivalent to or substantially equivalent to R-404A. It has a tendency to be comparable and preferably have as high or higher capacity and / or efficiency as this. In particular, Applicants have noted that some preferred embodiments of the present compositions preferably have a relatively low global warming potential (GWP) of less than about 2500, more preferably less than about 2400, and even more preferably less than about 2300. Recognized that there is a tendency to show. In some embodiments, the composition has a GWP of about 1500 or less, even more preferably less than about 1000.

  In some other preferred embodiments, the composition is used in a cooling system that contained R-404A and / or was originally designed for use with R-404A. Preferred cooling compositions of the present invention can be used in cooling systems that include lubricants commonly used with R-404A, such as mineral oil, polyalkylbenzene, polyalkylene glycol oil, etc., or traditionally used with HFC refrigerants. It can be used with other lubricants. As used herein, the term “cooling system” generally refers to any system or device that uses a refrigerant to provide cooling, or any component or part of such a system or device. Examples of such a cooling system include an air conditioner, an electric refrigerator, a refrigerator (including a refrigerator using a centrifugal compressor), and the like.

  As mentioned above, the present invention achieves significant advantages with respect to systems known as cryogenic cooling systems. As used herein, the term “cold cooling system” refers to a vapor compression cooling system that employs one or more compressors and a condenser temperature of about 35 ° C. to about 45 ° C. In a preferred embodiment of such a system, the system has an evaporator temperature of about −40 ° C. to less than about −15 ° C., more preferably about −35 ° C. to about −25 ° C., and the evaporator temperature is preferably about −32. ° C. Further, in a preferred embodiment of such a system, the system has a degree of superheat at the evaporator outlet from about 0 ° C. to about 10 ° C., and the degree of superheat at the evaporator outlet is preferably from about 4 ° C. to about 6 ° C. Further, in a preferred embodiment of such a system, the system has a degree of superheat in the suction line of about 15 ° C to about 25 ° C, and the degree of superheat in the suction line is preferably about 20 ° C to about 25 ° C.

  In one non-limiting aspect, the heat transfer composition of the present invention is used to completely drain the existing refrigerant with or without the need to substantially modify the system. Existing cooling systems can be modified with or without. In one form, a portion of the refrigerant charge (which can include 5%, 10%, 25%, 50%, 75%, etc.) is drained from the system. The removed refrigerant charge is then replaced with one or a combination of the non-flammable low GWP refrigerants discussed herein.

  In another aspect, rather than partially draining an existing system, the refrigerant of the present invention can be used to “fill up” an existing system after a partial refrigerant leak. For example, many commercial systems have a relatively high refrigerant leakage rate, which necessitates routine addition of refrigerant over the life of the system. In one method of the present invention, the cooling system is provided with an amount of refrigerant that is less than the full or designed charge in the system (this occurs in the preferred embodiment as a result of refrigerant leakage from the system). The refrigerant composition of the present invention is preferably used to refill the system during normal refill maintenance. For example, if R404A leaks from the system, refill one or a combination of the blends defined herein. The method substantially maintains the capacity of the system, maintains or improves energy efficiency (lower power consumption equal to the lower operating cost for the user), and lowers the GWP of the refrigerant contained in the system. The above can be done while (reducing environmental impact). In a preferred embodiment, such a method can be performed regardless of how much refrigerant has leaked, preferably without performing blend calculations, and without deviating from the routine maintenance schedule of the system. Provide a simple (and low cost) way to reduce the environmental impact associated with system refilling.

  In accordance with the above, Applicants have found that even relatively large amounts of R404A, when used in combination with the blends of the present invention, are in the form of unintentional contaminants or as intentionally added ingredients? Or as a refrigerant remaining after replacement or refilling of the system, it has been recognized that it does not have a substantially detrimental effect on the performance of the refrigerant and / or cooling system of the present invention. In contrast, Applicants have also noted that relatively large amounts of the blends of the present invention in R404A, whether in the form of unintentional contaminants or as intentionally added components, It has also been recognized that it does not have a substantially detrimental effect on performance. Thus, in other cases, the presence of such contaminants may make it unsuitable to use a refrigerant having a contaminant, whereas applicants may use a mixture of such refrigerants. Has recognized that it will generally be acceptable for the intended purpose. Thus, one advantage of the methods and compositions of the present invention is that, from a workability standpoint, there is generally not much motivation to ensure that R404A is completely absent from low GWP refrigerants, and vice versa. As such, under such circumstances, the failure to use the method provided by the present invention increases the likelihood of significant severe problems with the operation of many existing automatic purge systems. However, the method overcomes these problems and adds reliability, safety, and efficiency to the system.

The following examples are given for the purpose of illustrating the invention but do not limit the scope thereof.
Example 1: Performance parameters:
The coefficient of performance (COP) is a generally accepted indicator of refrigerant performance that is particularly useful for representing the relative thermodynamic efficiency of a refrigerant in a particular heating or cooling cycle with refrigerant evaporation or condensation. . In cooling engineering, this term refers to the ratio of useful cooling to the energy applied by the compressor in compressing the vapor. The capacity of the refrigerant represents the amount of cooling or heating it provides and gives some indication of the ability of the compressor to deliver a given amount of heat for a given volume flow of refrigerant. In other words, considering a particular compressor, a higher capacity refrigerant provides more cooling or heating power. One means of assessing the COP of a refrigerant under specific operating conditions is to assess the refrigerant's thermodynamic properties using standard cooling cycle analysis techniques (eg, RC Downing, FLUOROCARBON REFRIGERANTS HANDBOOK, Chapter 3 , Prentice-Hall, 1988).

  Give a cryogenic cooling system. In the case of such a system shown in this example, the condenser temperature is set to 40.55 ° C. (which generally corresponds to an outdoor temperature of about 35 ° C.). The degree of supercooling at the expansion device inlet is set to 5.55 ° C. The evaporation temperature is set to -31.6 ° C (this corresponds to a box temperature of about -26 ° C). The degree of superheat at the evaporator outlet is set to 5.55 ° C. The degree of superheat in the suction line is set to 13.88 ° C. and the compressor efficiency is set to 65%. Pressure drop and heat transfer in the connecting lines (suction and liquid lines) are considered negligible and heat dissipation through the compressor shell is ignored. Several operating parameters were measured for the compositions A1-A4 shown in Table A above according to the present invention, and these operating parameters were measured as 100% COP value, 100% capacity value, and 97.6 ° C release temperature. The HFC-404A possessed is reported in Table 1 below.

  As can be seen from Table 1 above, Applicants have found that the compositions of the present invention are close to the parameters for R-404A, and in particular whether such compositions are used as drop-in replacements for R-404A in cryogenic cooling systems. And / or found that many of the critical cooling system performance parameters that are close enough to be used in such existing systems with only minor system changes can be achieved simultaneously. . For example, Compositions A1-A4 exhibit a capability in this cryogenic cooling system that is within about 8%, even more preferably within about 5% of that of R404A. All of these blends have an efficiency (COP) that is as much as 10% higher than that of R404A, which is highly desirable. Particularly considering the improved GWP of compositions A1-A4, these compositions of the present invention include drop-in for cryogenic cooling systems that originally contain and / or are designed to contain R-404A. It is an excellent candidate substance for use as a substitute.

  Many existing cryogenic cooling systems are designed for R-404A or other refrigerants with similar properties to R-404A, so that those skilled in the art can make relatively minimal modifications to the system. It will recognize the substantial advantages of refrigerants with low GWP and superior efficiency that can be made and used as an alternative to R-404A or similar refrigerants. Furthermore, those skilled in the art will recognize that the present compositions can preferably provide substantial advantages for use in new or newly designed cooling systems, such as cryogenic cooling systems.

Example 2: Modified parameters:
In some aspects, the present invention preferably does not substantially modify the system, and even more preferably does not include any major system components such as compressors, condensers, evaporators, and expansion valves. A modification method is provided that includes removing at least a portion of the existing refrigerant from the system and replacing at least a portion of the removed refrigerant with the composition of the present invention without alteration. Because of some features of cryogenic cooling systems, such as cryogenic cooling systems that specifically contain or are designed to contain R404A refrigerant, in some embodiments, such systems are reliable systems that use drop-in refrigerants. It is important to be able to show operating parameters. Such operating parameters include the following.

  A high side pressure that is within about 105%, even more preferably within about 103% of the high side pressure of the system using R404A. This parameter is important in such embodiments as it allows existing pressure components to be used.

  A release temperature, preferably below about 130 ° C., and even more preferably below about 125 ° C. The advantage of such a feature is that it can make it possible to use an existing device without activating the thermal protection device of the system, which is preferably designed to protect the components of the compressor. This parameter is advantageous in avoiding the use of expensive controls such as liquid injection to lower the discharge temperature.

  • Lower suction pressures can be accepted if they do not cause the system to subatmospheric pressure at low evaporation temperatures. This positive pressure is necessary to ensure that the system always has a positive pressure and avoids the inclusion of moist air in the event of a leak. To assess this requirement, a characteristic called “normal boiling point” (NBT: boiling point at atmospheric pressure) of the fluid in question is used. This NBT must be as close as possible to that of the replacing fluid (R404A) and at least lower than the lowest evaporation temperature found in normal commercial systems (example is -40 ° C) .

  The above and other operating parameters are determined for the compositions A1-A4 shown in Table A above according to the present invention and these operating parameters are reported in Table 2 below.

  In some preferred embodiments, the replacement step does not require substantial redesign or modification of the system to accommodate the refrigerants of the present invention, and does not require replacement of major parts of the device. Is a substitution. This is also true for compositions A1-A4, which can generally be used in most retrofit procedures without major component changes. In all compositions A1-A4, the discharge pressure and temperature are below the limit values and the normal boiling point is equivalent to R404A, so they can be used in most existing cooling systems.

  Although the invention has been described with reference to preferred embodiments, those skilled in the art will recognize that various modifications can be made and components thereof can be replaced by equivalents without departing from the scope of the invention. I will. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the substantial scope thereof. Accordingly, the invention is not limited to the specific embodiments disclosed, but the invention is intended to encompass all embodiments encompassed within the scope of the appended claims and any claims appended hereto. Is done.

Claims (10)

  (A) about 20 wt% to about 30 wt% HFC-32; (b) about 20 wt% to about 30 wt% HFC-125; (c) about 0 wt% to about 15 wt% HFO-1234yf. And about 10 wt% to about 30 wt% HFO-1234ze; (d) about 15 wt% to about 30 wt% HFC-134a; wherein wt% is the component (a) to (d) in the composition ) Heat transfer composition based on the sum of   The heat transfer composition of claim 1, wherein the HFO-1234ze comprises trans-HFO-1234ze.   The heat transfer composition of claim 1 having a weight ratio of about 0.9: 1.2 to about 1.2: 0.9 HFC-32: HFC-125.   The heat transfer composition of claim 1, comprising greater than 0 wt% to about 15 wt% HFO-1234yf and from about 10 wt% to about 30 wt% HFO-1234ze.   The heat transfer composition of claim 1 having a weight ratio of 134a to a combination of HFO-1234ze and HFO-1234yf between about 5: 7 and about 1: 1.   The heat transfer composition of claim 1, wherein HFO-1234ze is provided in an amount of about 20% and HFO-1234yf is provided in an amount of about 9%.   The heat transfer composition of claim 1, wherein HFO-1234ze is provided in an amount of about 26%.   The heat transfer composition of claim 1, wherein HFO-1234ze is provided in an amount of about 17% and HFO-1234yf is provided in an amount of about 9%.   A method for replacing an existing heat transfer fluid contained within a heat transfer system, wherein at least a portion of the existing heat transfer fluid is removed from the system (wherein the existing heat transfer fluid is HFC-404A). ), (A) about 20 wt% to about 30 wt% HFC-32; (b) about 20 wt% to about 30 wt% HFC-125; (c) about 0 wt% to about 15 wt% HFO -1234yf, and about 15 wt% to about 30 wt% HFO-1234ze; (d) about 15 wt% to about 30 wt% HFC-134a; wherein wt% is from component (a) to The above method comprising replacing at least a portion of an existing heat transfer fluid by introducing into the system a heat transfer composition that is based on the sum of (d).   Compressors, condensers, and evaporators in fluid communication, and a heat transfer composition in the system, wherein the heat transfer composition comprises: (a) about 20 wt% to about 30 wt% HFC-32; b) about 20% to about 30% by weight of HFC-125; (c) about 0% to about 15% by weight of HFO-1234yf, and about 15% to about 30% by weight of HFO-1234ze; ) About 15 wt% to about 30 wt% HFC-134a; the wt% is based on the sum of components (a) to (d) in the composition and the condenser is about 35 ° C. A heat transfer system having an operating temperature of about 45 ° C.