WO2014036115A1

WO2014036115A1 - Method of recharging equipment designed for chlorodifluoromethane

Info

Publication number: WO2014036115A1
Application number: PCT/US2013/057038
Authority: WO
Inventors: Konstantinos Kontomaris
Original assignee: E. I. Du Pont De Nemours And Company
Priority date: 2012-08-30
Filing date: 2013-08-28
Publication date: 2014-03-06
Also published as: TW201412966A

Abstract

In accordance with the present invention a method is provided for recharging or topping-off refrigerant. The method comprises adding a second refrigerant to a refrigeration, air conditioning, heat pump or power cycle system containing HCFC-22 as a first refrigerant wherein said second refrigerant comprises at least one refrigerant selected from the group consisting of HFC-143a, HFC-125, and mixtures thereof, and optionally HCFC-22, thus producing a refrigerant composition comprising the first refrigerant and the second refrigerant. Also in accordance with the present invention another method is provided. This method comprises replacing HCFC-22 in a refrigeration, air conditioning, heat pump or power cycle system with a refrigerant composition comprising at least one refrigerant selected from the group consisting of HFC-143a, HFC-125, and mixtures thereof, and optionally HCFC-22.

Description

TITLE

METHOD OF RECHARGING EQUIPMENT DESIGNED FOR CHLORODIFLUOROM ETHANE

BACKGROUND

1 . Field of the Disclosure.

The present disclosure relates to a method for recharging or topping off the refrigerant charge in equipment designed to use

chlorodifluoromethane. The methods of the present invention are useful for adding or topping off refrigerants in refrigeration, air conditioning, heat pump or power cycle apparatus.

2. Description of Related Art.

The refrigeration industry has been working for the past few decades to find replacement refrigerants for the ozone depleting

chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) being phased out as a result of the Montreal Protocol. The solution for most refrigerant producers has been the commercialization of

hydrofluorocarbon (HFC) refrigerants. The new HFC refrigerants, HFC- 134a being the most widely used at this time, have zero ozone depletion potential and thus are not affected by the current regulatory phase out as a result of the Montreal Protocol.

Further environmental regulations may ultimately cause global phase out of certain HFC refrigerants. Currently, industry is facing regulations relating to global warming potential (GWP) and ozone depletion potential (ODP) for refrigerants. Should the regulations be more broadly applied in the future, an even greater need will be felt for refrigerants that can be used in all areas of the refrigeration and air-conditioning industry.

Uncertainty as to the ultimate regulatory requirements relative to GWP and ODP have forced the industry to consider multiple candidate compounds and mixtures. Proposed replacement refrigerants for HFC refrigerants must have low toxicity, low or no flammability, and improved energy efficiency, in addition to low global warming potential and low or no Ozone depletion potential.

As the use of certain refrigerants is banned or restricted, there is a need for refrigerants that are compatible with existing equipment. During regular operation, refrigerants can escape the system, requiring new refrigerant to be added. If the original refrigerant is only available in limited quantities or no longer available, then a compatible refrigerant must be identified or the equipment will need to be modified or replaced to provide comparable performance.

BRIEF SUMMARY

Certain existing refrigerants have been found to possess suitable properties to allow their use as a replacement for chlorodifluoromethane. Additionally, these refrigerants may provide appropriate refrigerant charge top-off candidates.

In accordance with the present invention a method is provided for recharging or topping-off refrigerant. The method comprises adding a second refrigerant to a refrigeration, air conditioning, heat pump or power cycle system containing HCFC-22 as a first refrigerant wherein said second refrigerant comprises at least one refrigerant selected from the group consisting of HFC-143a, HFC-125, or mixtures thereof and optionally HCFC-22, thus producing a refrigerant composition comprising the first refrigerant and the second refrigerant.

Also in accordance with the present invention another method is provided. This method comprises recharging a refrigeration system containing HCFC-22 with a refrigerant composition comprising at least one refrigerant selected from the group consisting of HFC-143a, HFC-125, and mixtures thereof, and optionally HCFC-22.

Also in accordance with the present invention another method is provided. This method comprises replacing HCFC-22 in a refrigeration, air conditioning, heat pump or power cycle system with a refrigerant composition comprising at least one refrigerant selected from the group consisting of HFC-143a, HFC-125, and mixtures thereof, and optionally HCFC-22.

DETAILED DESCRIPTION

Before addressing details of embodiments described below, some terms are defined or clarified.

Definitions

As used herein, the term heat transfer fluid means a composition used to carry heat from a heat source to a heat sink. A heat source is defined as any space, location, object or body from which it is desirable to add, transfer, move or remove heat. Examples of heat sources are spaces (open or enclosed) requiring refrigeration or cooling, such as refrigerator or freezer cases in a supermarket, building spaces requiring air conditioning, industrial water chillers or the passenger compartment of an automobile requiring air conditioning. In some embodiments, the heat transfer composition may remain in a constant state throughout the transfer process (i.e., not evaporate or condense). In other embodiments, evaporative cooling processes may utilize heat transfer compositions as well. A heat sink is defined as any space, location, object or body capable of absorbing heat. A vapor compression refrigeration system is one example of such a heat sink.

A refrigerant is defined as a heat transfer fluid that undergoes a phase change from liquid to gas and back again during the cycle used to transfer of heat.

A refrigerant charge is the total amount of refrigerant loaded into equipment in order for the equipment to operate with maximum

performance. Recharging (or topping-off or replenishing the charge) refers to adding additional refrigerant to return a system to maximum performance when some portion of the charge is lost or leaked from the equipment. A heat transfer system is the system (or apparatus) used to produce a heating or cooling effect in a particular space. A heat transfer system may be a mobile system or a stationary system.

Examples of heat transfer systems are any type of refrigeration systems and air conditioning systems including, but are not limited to, air conditioners, freezers, refrigerators, heat pumps, water chillers, flooded evaporator chillers, direct expansion chillers, walk-in coolers, mobile refrigerators, mobile air conditioning units, dehumidifiers, and

combinations thereof. As used herein, mobile heat transfer system refers to any

refrigeration, air conditioner or heating apparatus incorporated into a transportation unit for the road, rail, sea or air. In addition, mobile refrigeration or air conditioner units, include those apparatus that are independent of any moving carrier and are known as "intermodal" systems. Such intermodal systems include "container' (combined sea/land transport) as well as "swap bodies" (combined road/rail transport).

As used herein, stationary heat transfer systems are systems that are fixed in place during operation. A stationary heat transfer system may be associated within or attached to buildings of any variety or may be standalone devices located out of doors, such as a soft drink vending machine. These stationary applications may be stationary air conditioning and heat pumps, including but not limited to chillers, high temperature heat pumps, residential, commercial or industrial air conditioning systems (including residential heat pumps), and including window, ductless, ducted, packaged terminal, and those exterior but connected to the building such as rooftop systems. In stationary refrigeration applications, the disclosed compositions may be useful in equipment including commercial, industrial or residential refrigerators and freezers, ice machines, self-contained coolers and freezers, flooded evaporator chillers, direct expansion chillers, walk-in and reach-in coolers and freezers, and combination systems. In some embodiments, the disclosed compositions may be used in supermarket refrigeration systems. Additionally, stationary applications may utilize a secondary loop system that uses a primary refrigerant to produce cooling in one location that is transferred to a remote location via a secondary heat transfer fluid. Refrigeration capacity (also referred to as cooling capacity) is a term which defines the change in enthalpy of a refrigerant in an evaporator per pound of refrigerant circulated, or the heat removed by the refrigerant in the evaporator per unit volume of refrigerant vapor exiting the evaporator (volumetric capacity). The refrigeration capacity is a measure of the ability of a refrigerant or heat transfer composition to produce cooling.

Therefore, the higher the capacity, the greater the cooling that is produced. Cooling rate refers to the heat removed by the refrigerant in the evaporator per unit time.

Coefficient of performance (COP) is the amount of heat removed divided by the required energy input to operate the cycle. The higher the COP, the higher is the energy efficiency. COP is directly related to the energy efficiency ratio (EER) that is the efficiency rating for refrigeration or air conditioning equipment at a specific set of internal and external temperatures. The term "subcooling" refers to the reduction of the temperature of a liquid below that liquid's saturation point for a given pressure. The saturation point is the temperature at which the vapor is completely condensed to a liquid, but subcooling continues to cool the liquid to a lower temperature liquid at the given pressure. By cooling a liquid below the saturation temperature (or bubble point temperature), the net refrigeration capacity can be increased. Subcooling thereby improves refrigeration capacity and energy efficiency of a system. Subcool amount is the amount of cooling below the saturation temperature (in degrees).

Superheat is a term that defines how far above its saturation vapor temperature (the temperature at which, if the composition is cooled, the first drop of liquid is formed, also referred to as the "dew point") a vapor composition is heated. Temperature glide (sometimes referred to simply as "glide") is the absolute value of the difference between the starting and ending

temperatures of a phase-change process by a refrigerant within a component of a refrigerant system, exclusive of any subcooling or superheating. This term may be used to describe condensation or evaporation of a near azeotrope or non-azeotropic composition. When referring to the temperature glide of a refrigeration, air conditioning or heat pump system, it is common to provide the average temperature glide being the average of the temperature glide in the evaporator and the temperature glide in the condenser.

By azeotropic composition is meant a constant-boiling mixture of two or more substances that behave as a single substance. One way to characterize an azeotropic composition is that the vapor produced by partial evaporation or distillation of the liquid has the same composition as the liquid from which it is evaporated or distilled, i.e., the mixture

distills/refluxes without compositional change. Constant-boiling

compositions are characterized as azeotropic because they exhibit either a maximum or minimum boiling point, as compared with that of the non- azeotropic mixture of the same compounds. An azeotropic composition will not fractionate within a refrigeration or air conditioning system during operation. Additionally, an azeotropic composition will not fractionate upon leakage from a refrigeration or air conditioning system.

An azeotrope-like composition (also commonly referred to as a "near- azeotropic composition") is a substantially constant boiling liquid admixture of two or more substances that behaves essentially as a single substance. One way to characterize an azeotrope-like composition is that the vapor produced by partial evaporation or distillation of the liquid has substantially the same composition as the liquid from which it was evaporated or distilled, that is, the admixture distills/refluxes without substantial composition change. Another way to characterize an azeotrope-like composition is that the bubble point vapor pressure and the dew point vapor pressure of the composition at a particular temperature are substantially the same. Herein, a composition is azeotrope-like if, after 50 weight percent of the composition is removed, such as by evaporation or boiling off, the difference in vapor pressure between the original composition and the composition remaining after 50 weight percent of the original composition has been removed is less than about 10 percent. A non-azeotropic (also referred to as zeotropic) composition is a mixture of two or more substances that behaves as a simple mixture rather than a single substance. One way to characterize a non-azeotropic composition is that the vapor produced by partial evaporation or distillation of the liquid has a substantially different composition as the liquid from which it was evaporated or distilled, that is, the admixture distills/refluxes with substantial composition change. Another way to characterize a non- azeotropic composition is that the bubble point vapor pressure and the dew point vapor pressure of the composition at a particular temperature are substantially different. Herein, a composition is non-azeotropic if, after 50 weight percent of the composition is removed, such as by evaporation or boiling off, the difference in vapor pressure between the original composition and the composition remaining after 50 weight percent of the original composition has been removed is greater than about 10 percent.

As used herein, the term "lubricant" means any material added to a composition or a compressor (and in contact with any heat transfer composition in use within any heat transfer system) that provides lubrication to the compressor to aid in preventing parts from seizing.

As used herein, compatibilizers are compounds which improve solubility of the hydrofluorocarbon of the disclosed compositions in heat transfer system lubricants. In some embodiments, the compatibilizers improve oil return to the compressor. In some embodiments, the composition is used with a system lubricant to reduce oil-rich phase viscosity.

As used herein, oil-return refers to the ability of a heat transfer composition to carry lubricant through a heat transfer system and return it to the compressor. That is, in use, it is not uncommon for some portion of the compressor lubricant to be carried away by the heat transfer composition from the compressor into the other portions of the system. In such systems, if the lubricant is not efficiently returned to the compressor, the compressor will eventually fail due to lack of lubrication.

As used herein, "ultra-violet" dye is defined as a UV fluorescent or phosphorescent composition that absorbs light in the ultra-violet or "near" ultra-violet region of the electromagnetic spectrum. The fluorescence produced by the UV fluorescent dye under illumination by a UV light that emits at least some radiation with a wavelength in the range of from 10 nanometers to about 775 nanometers may be detected. Flammability is a term used to mean the ability of a composition to ignite and/or propagate a flame. For refrigerants and other heat transfer compositions, the lower flammability limit ("LFL") is the minimum

concentration of the heat transfer composition in air that is capable of propagating a flame through a homogeneous mixture of the composition and air under test conditions specified in ASTM (American Society of Testing and Materials) E681 -04. The upper flammability limit ("UFL") is the maximum concentration of the heat transfer composition in air that is capable of propagating a flame through a homogeneous mixture of the composition and air under the same test conditions. In order to be classified by ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) as non-flammable, a refrigerant must be nonflammable under the conditions of ASTM E681 -04 as formulated in the liquid and vapor phase as well as non-flammable in both the liquid and vapor phases that result during leakage scenarios. Global warming potential (GWP) is an index for estimating relative global warming contribution due to atmospheric emission of a kilogram of a particular greenhouse gas compared to emission of a kilogram of carbon dioxide. GWP can be calculated for different time horizons showing the effect of atmospheric lifetime for a given gas. The GWP for the 100 year time horizon is commonly the value referenced. For mixtures, a weighted average can be calculated based on the individual GWPs for each component. Ozone depletion potential (ODP) is a number that refers to the amount of ozone depletion caused by a substance. The ODP is the ratio of the impact on ozone of a chemical compared to the impact of a similar mass of CFC-1 1 (fluorotrichloromethane). Thus, the ODP of CFC-1 1 is defined to be 1 .0. Other CFCs and HCFCs have ODPs that range from 0.01 to 1 .0. HFCs have zero ODP because they do not contain chlorine.

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

The transitional phrase "consisting of excludes any element, step, or ingredient not specified. If in the claim such would close the claim to the inclusion of materials other than those recited except for impurities ordinarily associated therewith. When the phrase "consists of appears in a clause of the body of a claim, rather than immediately following the preamble, it limits only the element set forth in that clause; other elements are not excluded from the claim as a whole. The transitional phrase "consisting essentially of is used to define a composition, method or apparatus that includes materials, steps, features, components, or elements, in addition to those literally disclosed provided that these additional included materials, steps, features, components, or elements do materially affect the basic and novel characteristic(s) of the claimed invention. The term 'consisting essentially of occupies a middle ground between "comprising" and 'consisting of. Typically, components of the refrigerant mixtures and the refrigerant mixtures themselves can contain minor amounts (e.g., less than about 0.5 weight percent total) of impurities and/or byproducts (e.g., from the manufacture of the refrigerant components or reclamation of the refrigerant components from other systems) which do not materially affect the novel and basic characteristics of the refrigerant mixture.

Where applicants have defined an invention or a portion thereof with an open-ended term such as "comprising," it should be readily understood that (unless otherwise stated) the description should be interpreted to also describe such an invention using the terms "consisting essentially of or "consisting of."

Also, use of "a" or "an" are employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.

Unless otherwise defined, 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 a particular passage is 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.

Chlorodifluoromethane (also referred to as HCFC-22 or R22), 1 ,1 ,1 - trifluoroethane (also referred to as HFC-143a or R143a),

pentafluoroethane (also referred to as HFC-125 or R125), 1 ,1 ,2,2- tetrafluoroethane (also referred to as HFC-134 or R134), 1 ,1 ,1 ,2- tetrafluoroethane (also referred to as HFC-134a or R134a),

difluoromethane (also referred to as HFC-32 or R32), difluoromethoxytrifluoronnethane (CF₃OCHF₂, also referred to as HFE- 125E), propane, propylene, cyclopropane, n-butane, isobutane, n- pentane, 2-methylbutane, 2,2-dimethylpropane and cyclopentane, are all available commercially from numerous chemical or refrigerant suppliers. 2,3,3,3-tetrafluoropropene may also be referred to as HFO-1234yf,

HFC-1234yf, or R1234yf. HFO-1234yf may be made by methods known in the art, such as by dehydrofluorination 1 ,1 ,1 ,2,3-pentafluoropropane (HFC-245eb) or 1 ,1 ,1 ,2,2-pentafluoropropane (HFC-245cb).

E-1 ,3,3,3-tetrafluoropropene (E-HFO-1234ze) may be prepared by dehydrofluorination of a 1 ,1 ,1 ,2,3-pentafluoropropane (HFC-245eb, CF₃CHFCH₂F) or 1 ,1 ,1 ,3,3-pentafluoropropane (HFC-245fa,

CF3CH2CHF2). The dehydrofluorination reaction may take place in the vapor phase in the presence or absence of catalyst, and also in the liquid phase by reaction with caustic, such as NaOH or KOH. These reactions are described in more detail in U.S. Patent Publication No. 2006/0106263, incorporated herein by reference. HFO-1234ze may exist as one of two configurational isomers, cis- or trans- (also referred to as the E- and Z- isomers respectively). E-HFO-1234ze is available commercially from certain fluorocarbon manufacturers. Methods of recharging or toppinq-off

During regular use of refrigeration, air conditioning, heat pump or power cycle equipment, refrigerant (or working fluid) may escape the system, lowering the performance of the equipment. To restore that performance, new refrigerant may be added to replace that which was lost. HCFC-22 refrigerant loss may vary from less than 1 wt% of charge annually to accidental complete loss of charge depending on equipment type and use conditions.

In one embodiment, a method is provided for recharging or topping-off the refrigerant charge. The method comprises adding a second refrigerant to a refrigeration, air conditioning, heat pump or power cycle system containing HCFC-22 as a first refrigerant wherein said second refrigerant comprises at least one refrigerant selected from the group consisting of HFC-143a, HFC-125, HFC-32, HFC-134, HFC-134a, HFE-125E, propylene, propane, cyclopropane, n-butane, isobutane, n-pentane, 2- methylbutane, 2,2-dimethylpropane, cyclopentane, HFO-1234yf, and E- HFO-1234ze, and optionally HCFC-22, thus producing a refrigerant composition comprising the first refrigerant and the second refrigerant.

In one embodiment, the second refrigerant comprises HFC-143a.

In another embodiment, the second refrigerant further comprises HCFC-22. In another embodiment, the second refrigerant further comprises HFC-125. In another embodiment the second refrigerant comprises a non-flammable refrigerant mixture of HFC-143a and a refrigerant selected from the group consisting of HCFC-22, HFC-125 and a mixture thereof. It is expected that mixtures of HFC-143a and either HCFC-22 or HFC-125 containing no more than about 60 weight percent HFC-143a will be non-flammable. Therefore, in another embodiment, the second refrigerant mixture comprises at least about 40 weight percent HCFC-22, HFC-125 or a mixture thereof. In another embodiment, the second refrigerant contains from about 40 weight percent to about 99 weight percent HCFC-22, HFC-125 or a mixture thereof.

In one embodiment, the second refrigerant comprises HFC-32. In another embodiment, the second refrigerant comprises HFC-134. In another embodiment, the second refrigerant comprises HFC-134a. In another embodiment, the second refrigerant comprises a mixture of HFC- 134 and HFC-134a. In another embodiment, the second refrigerant comprises HFE-125E. In another embodiment, the second refrigerant comprises propylene. In another embodiment, the second refrigerant comprises propane. In another embodiment, the second refrigerant comprises cyclopropane. In another embodiment, the second refrigerant comprises n-butane. In another embodiment, the second refrigerant comprises isobutane. In another embodiment, the second refrigerant comprises n-pentane. In another embodiment, the second refrigerant comprises 2-methylbutane. In another embodiment, the second refrigerant comprises 2,2-dimethylpropane. In another embodiment, the second refrigerant comprises cyclopentane. In another embodiment, the second refrigerant comprises HFO-1234yf. In another embodiment, the second refrigerant comprises E-HFO-1234ze. And in other embodiments, the second refrigerant comprises a mixture of at least two of HFC-143a, HFC-125, HFC-32, HFC-134, HFC-134a, HFE-125E, propylene, propane, cyclopropane, n-butane, isobutane, n-pentane, 2-methylbutane, 2,2- dimethylpropane, cyclopentane, HFO-1234yf, E-HFO-1234ze, or

HCFC-22. In another embodiment, the second refrigerant comprises a mixture of at least two of HFC-143a, HFC-125, or HCFC-22. In one embodiment, the refrigeration, air conditioning, heat pump or power cycle system comprises a refrigerant composition comprising HCFC-22 in an amount ranging from greater than 0 wt% to less than 100 wt% and the second refrigerant in an amount greater than 0 wt% to less than 100 wt%. In another embodiment, the refrigeration, air conditioning, heat pump or power cycle system comprises a refrigerant composition comprising HCFC-22 in an amount ranging from about 40 wt% to less than 100 wt% and the second refrigerant in an amount greater than 0 wt% to about 60 wt%. In another embodiment, the refrigeration, air conditioning, heat pump or power cycle system comprises a refrigerant composition comprising HCFC-22 in an amount ranging from about 40 wt% to about 99 wt% and the second refrigerant in an amount from about 1 wt% to about 60 wt%.

Vapor-compression air conditioning and heat pump systems include an evaporator, a compressor, a condenser, and an expansion device. A refrigeration cycle re-uses refrigerant in multiple steps producing a cooling effect in one step and a heating effect in a different step.

Compressors for use in refrigeration, air conditioning, or heat pump systems include dynamic (e.g. axial or centrifugal) compressors or positive displacement (e.g. reciprocating, screw or scroll) compressors. In one embodiment the refrigeration, air conditioning, or heat pump system comprises a centrifugal compressor. In another embodiment, the refrigeration, air conditioning, or heat pump system comprises a positive displacement compressor.

In one embodiment, the refrigeration, air conditioning, heat pump or power cycle system comprises a centrifugal compressor and the centrifugal compressor includes an impeller.

Expanders for use in power cycle systems include dynamic (e.g. axial or centrifugal) expanders or positive displacement (e.g. reciprocating, screw or scroll) expanders. In one embodiment the power cycle system comprises a centrifugal expander (i.e. a turbine). In another embodiment the power cycle system comprises a positive displacement expander.

In one embodiment of the present method the refrigeration, air conditioning, heat pump or power cycle system comprises a chiller. In another embodiment, the chiller is a centrifugal chiller.

In one embodiment of the present method the refrigeration, air conditioning, heat pump or power cycle system comprises a heat pump. In another embodiment, the heat pump is a centrifugal heat pump.

In one embodiment of the present method the refrigeration, air conditioning, heat pump or power cycle system comprises an organic Rankine cycle system. In order to gain full benefit from the presently disclosed method, existing equipment containing R22 as refrigerant will be utilized with a second refrigerant added. The recharge or top-off with a second refrigerant must provide performance within certain limits as compared to optimum conditions with the R22 refrigerant. Therefore, in one

embodiment, the average temperature glide remains less than about 1 °C. In another embodiment, the average temperature glide remains less than about 0.75°C. In another embodiment, the average temperature glide remains less than about 0.5°C. In another embodiment, the average temperature glide remains less than about 0.25°C. In another

embodiment, the average temperature glide remains less than about 0.16°C. In one embodiment, the refrigeration, air conditioning, heat pump or power cycle system comprises a flooded evaporator, a flooded condenser or a combination thereof. Flooded evaporator and/or condenser systems cannot operate efficiently with elevated temperature glide. Therefore, minimum glide is necessary for the present inventive compositions and methods to be effective with these systems.

In one embodiment, the cooling capacity for the system after addition of the second refrigerant remains within 10% of the cooling capacity for the system operating with a full charge of HCFC-22. In another

embodiment, the cooling capacity remains within 7% of the cooling capacity for the system operating with a full charge of HCFC-22. In another embodiment, the cooling capacity remains within 5% of the cooling capacity for the system operating with a full charge of HCFC-22. In another embodiment, the cooling capacity remains within 3% of the cooling capacity for the system operating with a full charge of HCFC-22. In another embodiment, the cooling capacity remains within 2% of the cooling capacity for the system operating with a full charge of HCFC-22. In another embodiment, the cooling capacity remains within 1 % of the cooling capacity for the system operating with a full charge of HCFC-22. In one embodiment, when the refrigeration, air conditioning, heat pump or power cycle system comprises a centrifugal compressor, the impeller tip speed for the centrifugal compressor remains within 10% of the impeller tip speed for the centrifugal compressor in the system operating with a full charge of HCFC-22. In another embodiment, the impeller tip speed for the centrifugal compressor remains within 7% of the impeller tip speed for the centrifugal compressor in the system operating with a full charge of HCFC-22. In another embodiment, the impeller tip speed for the centrifugal compressor remains within 5% of the impeller tip speed for the centrifugal compressor in the system operating with a full charge of HCFC-22. In another embodiment, the impeller tip speed for the centrifugal compressor remains within 3% of the impeller tip speed for the centrifugal compressor in the system operating with a full charge of HCFC- 22. In another embodiment, the impeller tip speed for the centrifugal compressor remains within 2% of the impeller tip speed for the centrifugal compressor in the system operating with a full charge of HCFC-22. In another embodiment, the impeller tip speed for the centrifugal compressor remains within 1 % of the impeller tip speed for the centrifugal compressor in the system operating with a full charge of HCFC-22.

Vapor compression refrigeration, air conditioning, heat pump or power cycle systems also contain at least one lubricant that functions to lubricate compressor or expander moving parts and prevent seizing. Lubricants are chosen based on the refrigerant to be used in the system. A system using R22 as the refrigerant generally uses mineral oil type lubricants. As hydrofluorocarbon (HFC) or hydrofluorolefin (HFO) refrigerants such as HFC-143a etc. are added to such a system as a top-off or recharge refrigerant (the second refrigerant) miscibility with the mineral oil type lubricants will decrease. In order to maintain proper operation of the system, it may be necessary to add another lubricant that is more miscible with the HFC type refrigerants. Therefore, in one embodiment the method further comprises adding at least one lubricant. In another embodiment, the refrigeration, air conditioning, heat pump or power cycle system contains a first lubricant and the method further comprises replacing at least a portion of the first lubricant with a second lubricant.

In one embodiment, the lubricant to be added is chosen from polyol esters (POE), polyvinyl ethers (PVE), mineral oils or mixtures thereof.

In some embodiments, the lubricant is a mineral oil lubricant. In some embodiments, the mineral oil lubricant is selected from the group consisting of paraffins (including straight carbon chain saturated hydrocarbons, branched carbon chain saturated hydrocarbons, and mixtures thereof), naphthenes (including saturated cyclic and ring structures), aromatics (those with unsaturated hydrocarbons containing one or more ring, wherein one or more ring is characterized by alternating carbon-carbon double bonds) and non-hydrocarbons (those molecules containing atoms such as sulfur, nitrogen, oxygen and mixtures thereof), and mixtures and combinations of thereof. Some embodiments may contain one or more synthetic lubricant. In some embodiments, the synthetic lubricant is selected from the group consisting of alkyl substituted aromatics (such as benzene or naphthalene substituted with linear, branched, or mixtures of linear and branched alkyl groups, often generically referred to as alkylbenzenes), synthetic paraffins and napthenes, poly (alpha olefins), polyglycols (including polyalkylene glycols), dibasic acid esters, polyesters, polyol esters, neopentyl esters, polyvinyl ethers (PVEs), silicones, silicate esters, fluorinated compounds, phosphate esters, polycarbonates and mixtures thereof, meaning mixtures of the any of the lubricants disclosed in this paragraph.

The lubricants as disclosed herein may be commercially available lubricants. For instance, the lubricant may be paraffinic mineral oil, sold by BVA Oils as BVM 100 N, naphthenic mineral oils sold by Crompton Co. under the trademarks Suniso^® 1 GS, Suniso^® 3GS and Suniso^® 5GS, naphthenic mineral oil sold by Pennzoil under the trademark Sontex^® 372LT, naphthenic mineral oil sold by Calumet Lubricants under the trademark Calumet^® RO-30, linear alkylbenzenes sold by Shrieve

Chemicals under the trademarks Zerol^® 75, Zerol^® 150 and Zerol^® 500 and branched alkylbenzene sold by Nippon Oil as HAB 22, polyol esters (POEs) sold under the trademark Castrol^® 100 by Castrol, United

Kingdom, polyalkylene glycols (PAGs) such as RL-488A from Dow (Dow Chemical, Midland, Michigan), and mixtures thereof, meaning mixtures of any of the lubricants disclosed in this paragraph.

The lubricants used with the present invention may be designed for use with hydrofluorocarbon refrigerants and may be miscible with compositions as disclosed herein under compression refrigeration and air- conditioning apparatus' operating conditions. In some embodiments, the lubricants are selected by considering a given compressor's or expander's requirements and the environment to which the lubricant will be exposed. Notwithstanding the above weight ratios for compositions disclosed herein, it is understood that in some heat transfer systems, while the composition is being used, it may acquire additional lubricant from one or more equipment components of such heat transfer system. For example, in some refrigeration, air conditioning, heat pump or power cycle systems, lubricants may be charged in the compressor and/or the compressor lubricant sump or the expander. Such lubricant would be in addition to any lubricant additive present in the refrigerant in such a system. In use, the refrigerant composition when in the compressor or the expander may pick up an amount of the equipment lubricant to change the refrigerant- lubricant composition from the starting ratio.

In some embodiments, the compositions including R22 and a second refrigerant may include optional non-refrigerant components (also referred to herein as additives). The optional non-refrigerant components in the compositions disclosed herein may comprise one or more components selected from the group consisting of dyes (including UV dyes), solubilizing agents, compatibilizers, stabilizers, tracers,

perfluoropolyethers, anti-wear agents, extreme pressure agents, corrosion and oxidation inhibitors, metal surface energy reducers, metal surface deactivators, free radical scavengers, foam control agents, viscosity index improvers, pour point depressants, detergents, viscosity adjusters, and mixtures thereof. Indeed, many of these optional non-refrigerant components fit into one or more of these categories and may have qualities that lend themselves to achieve one or more performance characteristic.

In some embodiments, one or more non-refrigerant components are present in small amounts relative to the overall composition. In some embodiments, the amount of additive(s) concentration in the disclosed compositions is from less than about 0.1 weight percent to as much as about 5 weight percent of the total composition. In some embodiments of the present invention, the additives are present in the disclosed

compositions in an amount between about 0.1 weight percent to about 5 weight percent of the total composition or in an amount between about 0.1 weight percent to about 3.5 weight percent. The additive

component(s) selected for the disclosed composition is selected on the basis of the utility and/or individual equipment components or the system requirements.

In the compositions of the present invention including a lubricant, the lubricant is present in an amount of less than 5.0 weight percent to the total composition. In other embodiments, the amount of lubricant is between about 0.1 and 3.5 weight percent of the total composition.

The non-refrigerant component used with the compositions of the present invention may include at least one dye. The dye may be at least one ultra-violet (UV) dye. The UV dye may be a fluorescent dye. The fluorescent dye may be selected from the group consisting of

naphthalimides, perylenes, coumarins, anthracenes, phenanthracenes, xanthenes, thioxanthenes, naphthoxanthenes, fluoresceins, and derivatives of said dye, and combinations thereof, meaning mixtures of any of the foregoing dyes or their derivatives disclosed in this paragraph. In some embodiments, the disclosed compositions contain from about

0.001 weight percent to about 1 .0 weight percent UV dye. In other embodiments, the UV dye is present in an amount of from about

0.005 weight percent to about 0.5 weight percent; and in other

embodiments, the UV dye is present in an amount of from 0.01 weight percent to about 0.25 weight percent of the total composition.

UV dye is a useful component for detecting leaks of the composition by permitting one to observe the fluorescence of the dye at or in the vicinity of a leak point in an apparatus (e.g., refrigeration unit, air- conditioner or heat pump). The UV emission, e.g., fluorescence from the dye may be observed under an ultra-violet light. Therefore, if a

composition containing such a UV dye is leaking from a given point in an apparatus, the fluorescence can be detected at the leak point, or in the vicinity of the leak point.

Another non-refrigerant component which may be used with the compositions of the present invention may include at least one solubilizing agent selected to improve the solubility of one or more dye in the disclosed compositions. In some embodiments, the weight ratio of dye to solubilizing agent ranges from about 99:1 to about 1 :1 . The solubilizing agents include at least one compound selected from the group consisting of hydrocarbons, hydrocarbon ethers, polyoxyalkylene glycol ethers (such as dipropylene glycol dimethyl ether), amides, nitriles, ketones,

chlorocarbons (such as methylene chloride, trichloroethylene, chloroform, or mixtures thereof), esters, lactones, aromatic ethers, fluoroethers and 1 ,1 ,1 -trifluoroalkanes and mixtures thereof, meaning mixtures of any of the solubilizing agents disclosed in this paragraph.

In some embodiments, the non-refrigerant component comprises at least one compatibilizer to improve the compatibility of one or more lubricants with the disclosed compositions. The compatibilizer may be selected from the group consisting of hydrocarbons, hydrocarbon ethers, polyoxyalkylene glycol ethers (such as dipropylene glycol dimethyl ether), amides, nitriles, ketones, chlorocarbons (such as methylene chloride, trichloroethylene, chloroform, or mixtures thereof), esters, lactones, aromatic ethers, fluoroethers, 1 ,1 ,1 -trifluoroalkanes, and mixtures thereof, meaning mixtures of any of the compatibilizers disclosed in this paragraph.

The solubilizing agent and/or compatibilizer may be selected from the group consisting of hydrocarbon ethers consisting of the ethers containing only carbon, hydrogen and oxygen, such as dimethyl ether (DME) and mixtures thereof, meaning mixtures of any of the hydrocarbon ethers disclosed in this paragraph.

The compatibilizer may be linear or cyclic aliphatic or aromatic hydrocarbon compatibilizer containing from 3 to 15 carbon atoms. For systems wherein the second refrigerant is a hydrocarbon, such as propane, propylene, cyclopropane, n-butane, isobutane, n-pentane, 2- methylbutane, 2,2-dimethylpropane, or cyclopentane, compatibilizers for the mineral oil lubricants would not be necessary. However, for the HFC and HFO refrigerants hydrocarbons including propane, propylene, cyclopropane and others selected from the group consisting of n-butane, isobutane, n-pentane, isopentane, hexanes, octanes, nonane, and decanes, among others. Commercially available hydrocarbon compatibilizers include but are not limited to those from Exxon Chemical (USA) sold under the trademarks Isopar^® H, a mixture of undecane (Cn) and dodecane (Ci₂) (a high purity C to Ci₂ iso-paraffinic), Aromatic 150 (a Cg to Cn aromatic) (, Aromatic 200 (a Cg to Ci₅ aromatic) and Naptha 140 (a mixture of C₅ to Cn paraffins, naphthenes and aromatic

hydrocarbons) and mixtures thereof, meaning mixtures of any of the hydrocarbons disclosed in this paragraph.

The compatibilizer may alternatively be at least one polymeric compatibilizer. The polymeric compatibilizer may be a random copolymer of fluorinated and non-fluorinated acrylates, wherein the polymer comprises repeating units of at least one monomer represented by the formulae CH₂=C(R¹)CO₂R², CH₂=C(R³)C₆H₄R⁴, and CH₂=C(R⁵)C₆H₄XR⁶, wherein X is oxygen or sulfur; R¹, R³, and R⁵ are independently selected from the group consisting of H and Ci-C alkyl radicals; and R², R⁴, and R⁶ are independently selected from the group consisting of carbon-chain- based radicals containing C, and F, and may further contain H, CI, ether oxygen, or sulfur in the form of thioether, sulfoxide, or sulfone groups and mixtures thereof. Examples of such polymeric compatibilizers include those commercially available from E. I. du Pont de Nemours and

Company, (Wilmington, DE, 19898, USA) under the trademark Zonyl^® PHS. Zonyl^® PHS is a random copolymer made by polymerizing 40 weight percent CH₂=C(CH₃)CO₂CH₂CH₂(CF₂CF₂)_mF (also referred to as Zonyl^® fluoromethacrylate or ZFM) wherein m is from 1 to 12, primarily 2 to 8, and 60 weight percent lauryl methacrylate

(CH^CiCHsJCO^CH^ CHs, also referred to as LMA).

In some embodiments, the compatibilizer component contains from about 0.01 to 30 weight percent (based on total amount of compatibilizer) of an additive which reduces the surface energy of metallic copper, aluminum, steel, or other metals and metal alloys thereof found in heat exchangers in a way that reduces the adhesion of lubricants to the metal. Examples of metal surface energy reducing additives include those commercially available from DuPont under the trademarks Zonyl^® FSA, Zonyl^® FSP, and Zonyl^® FSJ. Another non-refrigerant component which may be used with the compositions of the present invention may be a metal surface deactivator. The metal surface deactivator is selected from the group consisting of areoxalyl bis (benzylidene) hydrazide (CAS reg no. 6629-10-3), Ν,Ν'- bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamoylhydrazine (CAS reg no. 32687-78-8) , 2,2,' - oxamidobis-ethyl-(3,5-di-tert-butyl-4- hydroxyhydrocinnamate (CAS reg no. 70331 -94-1 ), N,N'-(disalicyclidene)- 1 ,2-diaminopropane (CAS reg no. 94-91 -7) and ethylenediaminetetra- acetic acid (CAS reg no. 60-00-4) and its salts, and mixtures thereof, meaning mixtures of any of the metal surface deactivators disclosed in this paragraph.

The non-refrigerant component used with the compositions of the present invention may alternatively be a stabilizer selected from the group consisting of hindered phenols, thiophosphates, butylated

tnphenylphosphorothionates, organo phosphates, or phosphites, aryl alkyl ethers, terpenes, terpenoids, epoxides, fluorinated epoxides, oxetanes, ascorbic acid, thiols, lactones, thioethers, amines, nitromethane, alkylsilanes, benzophenone derivatives, aryl sulfides, divinyl terephthalic acid, diphenyl terephthalic acid, ionic liquids, and mixtures thereof, meaning mixtures of any of the stabilizers disclosed in this paragraph.

The stabilizer may be selected from the group consisting of

tocopherol; hydroquinone; t-butyl hydroquinone; monothiophosphates; and dithiophosphates, commercially available from Ciba Specialty Chemicals, Basel, Switzerland, hereinafter "Ciba", under the trademark Irgalube^® 63; dialkylthiophosphate esters, commercially available from Ciba under the trademarks Irgalube^® 353 and Irgalube^® 350, respectively; butylated tnphenylphosphorothionates, commercially available from Ciba under the trademark Irgalube^® 232; amine phosphates, commercially available from Ciba under the trademark Irgalube^® 349 (Ciba); hindered phosphites, commercially available from Ciba as Irgafos^® 168 and Tris-(di-tert- butylphenyl)phosphite, commercially available from Ciba under the trademark Irgafos^® OPH; (Di-n-octyl phosphite); and iso-decyl diphenyl phosphite, commercially available from Ciba under the trademark Irgafos^® DDPP; trialkyl phosphates, such as trimethyl phosphate,

triethylphosphate, tributyl phosphate, trioctyl phosphate, and tri(2- ethylhexyl)phosphate; triaryl phosphates including triphenyl phosphate, tricresyl phosphate, and trixylenyl phosphate; and mixed alkyl-aryl phosphates including isopropylphenyl phosphate (IPPP), and bis(t- butylphenyl)phenyl phosphate (TBPP); butylated triphenyl phosphates, such as those commercially available under the trademark Syn-O-Ad^® including Syn-O-Ad^® 8784; tert-butylated triphenyl phosphates such as those commercially available under the trademark Durad^®620;

isopropylated triphenyl phosphates such as those commercially available under the trademarks Durad^® 220 and Durad^®1 10; anisole; 1 ,4- dimethoxybenzene; 1 ,4-diethoxybenzene; 1 ,3,5-trimethoxybenzene;

myrcene, alloocimene, limonene (in particular, d-limonene); retinal;

pinene; menthol; geraniol; farnesol; phytol; Vitamin A; terpinene; delta-3- carene; terpinolene; phellandrene; fenchene; dipentene; caratenoids, such as lycopene, beta carotene, and xanthophylls, such as zeaxanthin;

retinoids, such as hepaxanthin and isotretinoin; bornane; 1 ,2-propylene oxide; 1 ,2-butylene oxide; n-butyl glycidyl ether; trifluoromethyloxirane; 1 ,1 -bis(trifluoromethyl)oxirane; 3-ethyl-3-hydroxymethyl-oxetane, such as OXT-101 (Toagosei Co., Ltd); 3-ethyl-3-((phenoxy)methyl)-oxetane, such as OXT-21 1 (Toagosei Co., Ltd); 3-ethyl-3-((2-ethyl-hexyloxy)methyl)- oxetane, such as OXT-212 (Toagosei Co., Ltd); ascorbic acid;

methanethiol (methyl mercaptan); ethanethiol (ethyl mercaptan);

Coenzyme A; dimercaptosuccinic acid (DMSA); grapefruit mercaptan ((R)- 2-(4-methylcyclohex-3-enyl)propane-2-thiol)); cysteine (( R)-2-amino-3- sulfanyl-propanoic acid); lipoamide (1 ,2-dithiolane-3-pentanamide); 5,7- bis(1 ,1 -dimethylethyl)-3-[2,3(or 3,4)-dimethylphenyl]-2(3H)-benzofuranone, commercially available from Ciba under the trademark Irganox^® HP-136; benzyl phenyl sulfide; diphenyl sulfide; diisopropylamine; dioctadecyl 3,3'- thiodipropionate, commercially available from Ciba under the trademark Irganox^® PS 802 (Ciba); didodecyl 3,3'-thiopropionate, commercially available from Ciba under the trademark Irganox^® PS 800; di-(2, 2,6,6- tetramethyl-4-piperidyl)sebacate, commercially available from Ciba under the trademark Tinuvin^® 770; poly-(N-hydroxyethyl-2,2,6,6-tetramethyl-4- hydroxy-piperidyl succinate, commercially available from Ciba under the trademark Tinuvin^® 622LD (Ciba); methyl bis tallow amine; bis tallow amine; phenol-alpha-naphthylamine; bis(dimethylamino)methylsilane (DMAMS); tris(trimethylsilyl)silane (TTMSS); vinyltriethoxysilane;

vinyltrimethoxysilane; 2,5-difluorobenzophenone; 2',5'- dihydroxyacetophenone; 2-aminobenzophenone; 2-chlorobenzophenone; benzyl phenyl sulfide; diphenyl sulfide; dibenzyl sulfide; ionic liquids; and mixtures and combinations thereof.

The additive used with the compositions of the present invention may alternatively be an ionic liquid stabilizer. The ionic liquid stabilizer may be selected from the group consisting of organic salts that are liquid at room temperature (approximately 25°C), those salts containing cations selected from the group consisting of pyridinium, pyridazinium, pyrimidinium, pyrazinium, imidazolium, pyrazolium, thiazolium, oxazolium and triazolium and mixtures thereof ; and anions selected from the group consisting of [BF ]-, [PF₆]-, [SbF₆]-, [CF₃SO₃]-, [HCF₂CF₂SO₃]-, [CF₃HFCCF₂SO₃]-, [HCCIFCF₂SO₃]-, [(CF₃SO₂)₂N]-, [(CF₃CF₂SO₂)₂N]-, [(CF₃SO₂)₃C]-,

[CF₃CO₂]-, and F- and mixtures thereof. In some embodiments, ionic liquid stabilizers are selected from the group consisting of emim BF (1 - ethyl-3-methylimidazolium tetrafluoroborate); bmim BF (1 -butyl-3- methylimidazolium tetraborate); emim PF₆ (1 -ethyl-3-methylimidazolium hexafluorophosphate); and bmim PF₆ (1 -butyl-3-methylimidazolium hexafluorophosphate), all of which are available from Fluka (Sigma- Aldrich). In some embodiments, the stabilizer may be a hindered phenol, which is any substituted phenol compound, including phenols comprising one or more substituted or cyclic, straight chain, or branched aliphatic substituent group, such as, alkylated monophenols including 2,6-di-tert-butyl-4- methylphenol; 2,6-di-tert-butyl-4-ethylphenol; 2,4-dimethyl-6- tertbutylphenol; tocopherol; and the like, hydroquinone and alkylated hydroquinones including t-butyl hydroquinone, other derivatives of hydroquinone; and the like, hydroxylated thiodiphenyl ethers, including 4,4'-thio-bis(2-methyl-6-tert-butylphenol); 4,4'-thiobis(3-methyl-6- tertbutylphenol); 2,2'-thiobis(4nnethyl-6-tert-butylphenol); and the like, alkylidene-bisphenols including,: 4,4'-methylenebis(2,6-di-tert- butylphenol); 4,4'-bis(2,6-di-tert-butylphenol); derivatives of 2,2'- or 4,4- biphenoldiols; 2,2'-methylenebis(4-ethyl-6-tertbutylphenol); 2,2'- methylenebis(4-nnethyl-6-tertbutylphenol); 4,4-butylidenebis(3-methyl-6- tert-butylphenol); 4,4-isopropylidenebis(2,6-di-tert-butylphenol); 2,2'- methylenebis(4-nnethyl-6-nonylphenol); 2,2'-isobutylidenebis(4,6- dimethylphenol; 2,2'-methylenebis(4-methyl-6-cyclohexylphenol, 2,2- or 4,4- biphenyldiols including 2,2'-methylenebis(4-ethyl-6-tert-butylphenol); butylated hydroxytoluene (BHT, or 2,6-di-tert-butyl-4-methylphenol), bisphenols comprising heteroatoms including 2,6-di-tert-alpha- dimethylamino-p-cresol, 4,4-thiobis(6-tert-butyl-m-cresol); and the like; acylaminophenols; 2,6-di-tert-butyl-4(N,N'-dimethylaminomethylphenol); sulfides including; bis(3-methyl-4-hydroxy-5-tert-butylbenzyl)sulfide;

bis(3,5-di-tert-butyl-4-hydroxybenzyl)sulfide and mixtures thereof, meaning mixtures of any of the phenols disclosed in this paragraph.

The non-refrigerant component which is used with compositions of the present invention may alternatively be a tracer. The tracer may be two or more tracer compounds from the same class of compounds or from different classes of compounds. In some embodiments, the tracer is present in the compositions at a total concentration of about 50 parts per million by weight (ppm) to about 1000 ppm, based on the weight of the total composition. In other embodiments, the tracer is present at a total concentration of about 50 ppm to about 500 ppm. Alternatively, the tracer is present at a total concentration of about 100 ppm to about 300 ppm.

The tracer may be selected from the group consisting of

hydrofluorocarbons (HFCs), deuterated hydrofluorocarbons,

perfluorocarbons, fluoroethers, brominated compounds, iodated

compounds, alcohols, aldehydes and ketones, nitrous oxide and

combinations thereof. Alternatively, the tracer may be selected from the group consisting of fluoroethane, 1 ,1 ,-difluoroethane, 1 ,1 ,1 -trifluoroethane, 1 ,1 ,1 ,3,3,3-hexafluoropropane, 1 ,1 ,1 ,2,3,3,3-heptafluoropropane,

1 ,1 ,1 ,3,3-pentafluoropropane, 1 ,1 ,1 ,3,3-pentafluorobutane, 1 ,1 ,1 ,2,3,4,4,5,5,5-decafluoropentane, 1 ,1 ,1 ,2,2,3,4,5,5,6,6,7,7,7- tridecafluoroheptane, iodotrifluoromethane, deuterated hydrocarbons, deuterated hydrofluorocarbons, perfluorocarbons, fluoroethers,

brominated compounds, iodated compounds, alcohols, aldehydes, ketones, nitrous oxide (N₂O) and mixtures thereof. In some embodiments, the tracer is a blend containing two or more hydrofluorocarbons, or one hydrofluorocarbon in combination with one or more perfluorocarbons.

The tracer may be added to the compositions of the present invention in predetermined quantities to allow detection of any dilution,

contamination or other alteration of the composition.

The additive which may be used with the compositions of the present invention may alternatively be a peril uoropolyether as described in detail in US2007-0284555, incorporated herein by reference.

It will be recognized that certain of the additives referenced above as suitable for the non-refrigerant component have been identified as potential refrigerants. However in accordance with this invention, when these additives are used, they are not present at an amount that would affect the novel and basic characteristics of the refrigerant mixtures of this invention. In one embodiment, the compositions disclosed herein may be prepared by any convenient method to combine the desired amounts of the individual components. A preferred method is to weigh the desired component amounts and thereafter combine the components in an appropriate vessel. Agitation may be used, if desired. Apparatus, Methods and Processes of Use

The compositions disclosed herein are useful as heat transfer compositions or refrigerants.

Mechanical vapor-compression refrigeration, air conditioning and heat pump systems include an evaporator, a compressor, a condenser, and an expansion device. A refrigeration cycle re-uses refrigerant in multiple steps producing a cooling effect in one step and a heating effect in a different step. The cycle can be described simply as follows. Liquid refrigerant enters an evaporator through an expansion device, and the liquid refrigerant boils in the evaporator, by withdrawing heat from the environment or a stream or body to be cooled, at a low temperature to form a vapor and produce cooling. Often air or a heat transfer fluid flows over or around the evaporator to transfer the cooling effect caused by the evaporation of the refrigerant in the evaporator to a body to be cooled. The low-pressure vapor enters a compressor where the vapor is compressed to raise its pressure and temperature. The higher-pressure (compressed) gaseous refrigerant then enters the condenser in which the refrigerant condenses and discharges its heat to the environment or a stream or body to be heated. The refrigerant returns to the expansion device through which the liquid expands from the higher-pressure level in the condenser to the low-pressure level in the evaporator, thus repeating the cycle. A power cycle system includes a heat source, working fluid heater, expander, condenser and a pump. The working fluid is heated by the heat source in the heater. The heated working fluid expands in the expander. The expansion process results in conversion of at least a portion of the heat energy supplied from the heat source into mechanical shaft power. The shaft power can be used to do any mechanical work by employing conventional arrangements of belts, pulleys, gears, transmissions or similar devices depending on the desired speed and torque required. The working fluid still in vapor form that exits the expander continues to the condenser where adequate heat rejection causes the fluid to condense to liquid. The working fluid in liquid form flows to a pump that elevates the pressure of the fluid so that it can be introduced back into the heater thus completing the power cycle loop.

A method is provided for replacing HCFC-22 in refrigeration, air conditioning, heat pump or power cycle systems equipment. The method comprises replacing leaked or otherwise lost HCFC-22 with at least one refrigerant selected from the group consisting of HFC-143a, HFC-125, , and optionally HCFC-22. In one embodiment, a method for producing cooling in refrigeration, air conditioning or heat pump equipment suitable for using HCFC-22 as a refrigerant is provided. The method comprises producing cooling in said equipment using a combination of HCFC-22 and at least one refrigerant selected from the group consisting of HFC-143a, HFC-125, and optionally HCFC-22, as refrigerant.

In one embodiment, refrigeration, air conditioning, heat pump or power cycle apparatus containing a refrigerant composition and suitable for using HCFC-22 as the refrigerant is provided. The apparatus is characterized by: containing the refrigerant composition of the present invention consisting of or consisting essentially of HCFC-22 and at least one refrigerant selected from the group consisting of HFC-143a, HFC-125, and E-HFO-1234ze.

In one embodiment, disclosed herein is a method for producing cooling comprising condensing a refrigerant composition of the present invention consisting of or consisting essentially of HCFC-22 and at least one refrigerant selected from the group consisting of HFC-143a, HFC-125, and thereafter evaporating said refrigerant in the vicinity of a body to be cooled. A body to be cooled may be defined as any space, location, object, stream or body from which it is desirable to remove heat. Examples include spaces (open or enclosed) requiring refrigeration or cooling, such as refrigerator or freezer cases in a supermarket.

In one embodiment, disclosed herein is a method for producing heating comprising evaporating a refrigerant composition of the present invention consisting of or consisting essentially of HCFC-22 and at least one refrigerant selected from the group consisting of HFC-143a, HFC-125, and thereafter compressing and condensing said refrigerant in the vicinity of a body to be heated. A body to be heated may be defined as any space, location, object, stream or body to which it is desirable to provide heat. Examples include spaces (open or enclosed) requiring heating, such as such as single family homes, town houses or multiple apartment buildings or public buildings.

For the process for producing cooling by vicinity is meant that the evaporator of the system containing the refrigerant mixture is located either within or adjacent to the body to be cooled, such that air moving over the evaporator would move into or around the body to be cooled. For the process to produce heating by vicinity is meant that the condenser of the system containing the refrigerant mixture is located either within or adjacent to the body to be heated, such that air moving over the

condenser would move into or around the body to be heated.

In some embodiments, the refrigerant mixtures as disclosed herein may be useful in refrigeration applications including medium temperature refrigeration in particular. Medium temperature refrigeration systems includes supermarket and convenience store refrigerated cases for beverages, dairy, fresh food transport and other items requiring

refrigeration. Other specific uses may be in commercial, industrial refrigerators and freezers, supermarket rack and distributed systems, walk-in and reach-in coolers and freezers, and combination systems.

In some embodiments, the compositions of the present invention may be useful in air conditioning applications. Air conditioning apparatus may be chillers, heat pumps, residential, commercial or industrial air

conditioning systems, and including ductless, ducted, packaged terminal, chillers, and those exterior but connected to the building such as rooftop systems. In particular the present method for replacing R22 or recharging or topping-off a system containing R22 is particularly useful for large equipment that requires a major investment to replace such as large flooded evaporator chillers and heat pumps. Use of the present methods would allow existing equipment to continue to operate even when R22 is restricted, available in limited quantities, costly or no longer available for top-off or recharge of the systems. In another embodiment is provided a method for recharging a refrigeration, air conditioning, heat pump or power cycle system that contains a refrigerant to be replaced and a lubricant, said method comprising removing the refrigerant to be replaced from the refrigeration or air conditioning or heat pump or power cycle system while retaining a substantial portion of the lubricant in said system and introducing one of the compositions of the present invention and additional lubricant to the refrigeration, air conditioning, heat pump or power cycle system.

In another embodiment, a refrigeration, air conditioning, heat pump or power cycle system comprising a composition disclosed herein is provided. Said systems may include condensing units, residential air conditioners, residential heat pumps, centrifugal or screw chillers, commercial centrifugal or screw heat pumps, and Rankine cycle systems.

In one embodiment, there is provided a refrigeration or air conditioning apparatus containing a composition as disclosed herein. In another embodiment is disclosed a refrigeration apparatus containing a

composition as disclosed herein. In another embodiment is disclosed an air conditioning apparatus containing a composition as disclosed herein. In another embodiment is disclosed a heat pump apparatus containing a composition as disclosed herein. The apparatus typically includes an evaporator, a compressor, a condenser, and an expansion device.

In another embodiment is disclosed a power cycle system apparatus. The apparatus typically includes an evaporator, an expander, a

condenser, and a liquid pump. In one embodiment is provided a refrigeration, air conditioning, heat pump or power cycle system comprising a chiller. In another embodiment, the chiller is a centrifugal chiller.

In one embodiment, is provided a refrigeration, air conditioning, heat pump or power cycle system comprising a heat pump. In another embodiment, the heat pump is a centrifugal heat pump. In one embodiment, is provided a refrigeration, air conditioning, heat pump or power cycle system comprising an organic Rankine cycle system.

In one embodiment is provided a method comprising recharging a refrigeration, air conditioning, heat pump or power cycle system system containing HCFC-22 with a refrigerant composition comprising at least one refrigerant selected from the group consisting of HFC-143a, HFC-125, and optionally HCFC-22.

In another embodiment is provided a method comprising replacing HCFC-22 in a refrigeration, air conditioning, heat pump or power cycle system with a refrigerant composition comprising at least one refrigerant selected from the group consisting of HFC-143a, HFC-125, and optionally HCFC-22. In another embodiment of the method for replacing, the refrigeration, air conditioning, heat pump or power cycle system comprises a centrifugal compressor. In another embodiment, of the method for replacing, the impeller tip speed for the centrifugal compressor remains within 10% of the impeller tip speed for the centrifugal compressor in the system operating with a full charge of HCFC-22.

EXAMPLES

The concepts disclosed herein will be further described in the following examples, which do not limit the scope of the invention described in the claims.

EXAMPLE 1

Topping-Off an HCFC-22 Centrifugal Chiller with HFC-143a

(Small Charge Losses; Τ_βν3ρ= 4.44°C)

The annual loss of working fluid from well-maintained centrifugal chillers is relatively low, usually in the range of 1 -2 wt% of the fluid charge per year. Replenishing HCFC-22 charge losses with HFC-143a would restore the thermodynamic performance of an HCFC-22 chiller close to the performance with a full charge of HCFC-22. The amount of HFC-143a that should be added for optimum chiller performance would be, generally, comparable to the amount of HCFC-22 lost. Table 1 compares chiller performance after replenishing HCFC-22 charge losses with HFC-143a so as that the restored charge contains up to 20 wt% HCFC-143a to performance with a full charge of HCFC-22.

For example, with a HCFC-22/HFC-143a charge containing 20 wt% HFC-143a: condenser pressure would be only 3.83% higher than with a full charge of neat HCFC-22, i.e. it would remain comfortably lower than the maximum design working pressure of most centrifugal chillers;

volumetric cooling capacity would be 0.55% higher than (i.e. effectively equal to) that with neat HCFC-22 and it would continue to meet the chiller cooling duty; the evaporator and condenser glides would be equal to 0.16°C, i.e. sufficiently small for acceptable performance of even flooded heat exchangers; and the impeller tip speed required to lift the fluid from the thermodynamic state of the evaporator to that of the condenser would be almost identical (within 0.5%) to the speed required with neat HCFC-22 thus requiring no major impeller retrofit. A small increase (by 1 .48%) in energy consumption would be incurred relative to the reference case of a full HCFC-22 charge. It is likely that HCFC-22/HFC-143a blends containing up to 20 wt% HCFC-143a would be non-flammable and compatible with chiller lubricants based on mineral oils. Addition of a small proportion of a hydrocarbon with three carbon atoms to a HCFC- 22/HFC-143a blend would increase the blend compatibility with mineral oil lubricants.

The results in Table 1 suggest that replenishing HCFC-22 losses up to 2 wt% of charge per year with HFC-143a could extend the useful life of a centrifugal chiller up to at least 10 years without significant performance deterioration. Even at higher charge make-up rates, chiller performance with HCFC-22/HFC-143a blends would be sufficient in many cases so as to favor addressing HCFC-22 charge losses by replenishing losses with HFC-143a and thus extending chiller life over alternatives (e.g. retrofitting the chiller with a different working fluid or replacing the chiller). Table 1

Centrifugal chiller performance with a full charge of HCFC-22 and charges containing varying weight fractions of HFC-143a up to 20 wt%. (T_eva_P=4.44⁰C; T_COnd=37.78⁰C;

Superheat=0°C; Subcooling= 0°C; Compressor Efficiency=0.70)

EXAMPLE 2

Topping-Off an HCFC-22 Centrifugal Chiller with HFC-143a

(Large Charge Losses; Τ_θν3ρ= 4.44°C)

Despite best efforts to reduce charge losses, in some cases charge loss rates from chillers could be substantially higher than in Example 1 . Moreover, a catastrophic loss of the total amount of fluid charge is possible. Table 2 compares chiller performance after replenishing HCFC-22 charge losses with HFC-143a so as that the restored charge contains more than 20 wt% HCFC-143a to performance with a full charge of HCFC-22. Blends with sufficiently high HFC-143a content would likely be flammable and would require some means of mitigating the associated flammability risk. Moreover, blends with sufficiently high HFC-143a contents could require means of ensuring adequate compatibility with mineral oil lubricants (e.g. addition of small proportions of hydrocarbons in the blend) or use of alternative lubricants (e.g. POE type lubricants).

Table 2 shows that the maximum condenser pressure of 1 .74 MPa (realized in the case of complete HCFC-22 replacement with HFC-143a) remains comfortably lower than the maximum design working pressure of most centrifugal chillers. Moreover, the volumetric cooling capacity, required impeller tip speed and evaporator and condenser glides in

Table 2 at any blend HCFC-143a content remain remarkably close to the values with neat HCFC-22. Therefore, even after replenishing more than about 30 wt% of HCFC-22 with HFC-143a a chiller originally designed for 5 and operated with neat HCFC-22 could continue to meet its cooling duty without major modifications. However, the chiller energy consumption would be higher, the higher the HFC-143a content in the chiller fluid charge.

Table 2

10 Centrifugal chiller performance with a full charge of

HCFC-22 and charges containing varying weight fractions of HFC-143a higher than 30 wt%. (T_evap=4.44⁰C; T_COnd=37.78⁰C; Superheat=0°C; Subcooling= 0°C; Compressor Efficiency=0.70)

EXAMPLE 3

15 Topping-Off an HCFC-22 Centrifugal Chiller with

HFC-143a/HFC-125 blends

(Large Charge Losses; Τ_θν3ρ= 4.44°C)

If a flammable working fluid is not acceptable in a certain HCFC-22 chiller application, HCFC-22 charge losses could be replenished by HFC-

20 143a/HFC-125 blends so as that the restored fluid charge contain a

sufficient proportion of HCFC-22 and HFC-125 to be non-flammable. Table 3 compares chiller performance after replenishing HCFC-22 charge losses with HFC-143a/HFC-125 blends of varying compositions to performance with a full charge of HCFC-22. Blends in Table 3 with

25 sufficiently high HFC-143a/HFC-125 contents could require means of ensuring adequate compatibility with mineral oil lubricants (e.g. addition of small proportions of hydrocarbons in the blend) or use of alternative lubricants (e.g. POE type lubricants).

Table 3 indicates that addition of HFC-125 along with HFC-143a to HCFC-22 to ensure non-flammability of the working fluid blend leads to larger deviations of chiller performance from performance with neat HCFC-22 than addition solely of HFC-143a. The condenser pressure remains comfortably lower than the maximum design working pressure of most centrifugal chillers. The evaporator and condenser glides remain sufficiently small to be acceptable in many cases. The chiller volumetric cooling capacity increases with increasing content of HFC-125. In some cases with working fluids containing larger proportions of HFC-125 it may be advantageous to adjust the impeller tip speed so as to better match the chiller duty specifications.

Table 3

Centrifugal chiller performance with a full charge of HCFC-22 and charges containing varying weight fractions of HFC-143a and HFC-125. (T_evap=4.44⁰C; T_COnd=37.78⁰C; Superheat=0°C;

Subcooling= 0°C; Compressor Efficiency=0.70)

Table 3 (Continued)

Table 3 (Continued)

Table 3 (Continued)

Table 3 (Continued)

Table 3 (Concluded)

Example 4

Topping-Off an HCFC-22 Centrifugal Chiller

with HFC-143a/HFC-125 (60/40 wt%) blends

(Large Charge Losses; Τ_θν3ρ= 4.44 °C)

HFC-143a/HFC-125 blends containing at least 40 wt% HFC-125 are non flammable according to US patent 5,21 1 ,867 by Shankland et al. issued on May 18, 1993. Table 4 compares chiller performance after replenishing HCFC-22 charge losses with HFC-143a/HFC-125 blends containing 40 wt% HFC-125 to performance with a full charge of HCFC- 22. The chiller performance in Table 4 would be sufficient in many cases so as to favor addressing HCFC-22 charge losses by replenishing losses with HFC-143a/HFC-125 blends containing 40 wt% HFC-125 and thus extending chiller life over alternatives (e.g. retrofitting the chiller with a different working fluid or replacing the chiller). Table 4

Centrifugal chiller performance with a full charge of HCFC-22 and charges containing varying weight fractions of HFC-143a and HFC-125 at a 60/40 ratio. (Teva_P=4.44 °C; T_COnd=37.78 °C; Superheat=0 °C; Subcooling= 0 °C;

Compressor Efficiency=0.70)

Table 4 (Continued)

Table 4 (Concluded)

EXAMPLE 5

Topping off a refrigerant charge of R22 with other HFC refrigerants

This invention provides a method for replenishing the diminished HCFC-22 charge of a chiller or other equipment and restoring

performance by adding one of the compositions of this invention. Tables 5, 6 and 7 show the performance achievable when topping off a refrigerant charge in equipment containing R22 when HFC-134, HFC-134a or HFC- 32 is used as the top-off refrigerant.

TABLE 5

Air conditioner performance with a full charge of HCFC-22 and charges containing varying weight fractions of HFC-134

(Tevap=4.44°C; Tcond=37.78°C; Superheat=0°C;

Subcooling= 0°C; Compressor Efficiency=0.70)

TABLE 6

Air conditioner performance with a full charge of HCFC-22 and charges containing varying weight fractions of HFC-134a

(Tevap=4.44°C; Tcond=37.78°C; Superheat=0°C;

Subcooling= 0°C; Compressor Efficiency=0.70)

TABLE 7

Air conditioner performance with a full charge of HCFC-22 and charges containing varying weight fractions of HFC-32

(Tevap=4.44°C; Tcond=37.78°C; Superheat=0°C;

Subcooling= 0°C; Compressor Efficiency=0.70)

The data shown in Tables 5, 6, and 7 demonstrate that certain amounts of HFC-134, HFC-134a or HFC-32 can be used to top-off a charge of R22 in cooling systems without substantial loss of performance. Adding HFC-134 to HCFC-22 so as to form blends with up to about 15 wt% HFC-134 would limit the loss of volumetric cooling capacity to less than about 6.5% relative to neat HCFC-22 (see Table 5). The condenser and evaporator glides would remain below about 1 °C. Adding HFC-134a to HCFC-22 so as to form blends with up to about 30 wt% HFC-134a would limit the loss of volumetric cooling capacity to less than about 10% relative to neat HCFC-22 (see Table 6). The condenser and evaporator glides would remain below about 1 °C. Adding HFC-32 to HCFC-22 so as to form blends with up to about 10 wt% HFC-134a would enhance volumetric cooling capacity to by about 9% relative to neat HCFC-22 (see Table 7). The condenser and evaporator glides would remain below about 1 .3°C.

SELECTED EMBODIMENTS

Embodiment A1 : A method comprising adding a second refrigerant to a refrigeration, air conditioning, heat pump or power cycle system containing HCFC-22 as a first refrigerant wherein said second refrigerant comprises at least one refrigerant selected from the group consisting of HFC-143a, HFC-125, and mixtures thereof, and optionally HCFC-22, thus producing a refrigerant composition comprising the first refrigerant and the second refrigerant.

Embodiment A2: The method of Embodiment A1 , wherein the second refrigerant comprises HFC-143a.

Embodiment A3: The method Embodiment A2, wherein the second refrigerant further comprises HCFC-22.

Embodiment A4: The method of any of Embodiments A2 - A3, wherein the second refrigerant further comprises HFC-125. Embodiment A5: The method of any of Embodiments A1 - A4, wherein the second refrigerant comprises a non-flammable refrigerant mixture of HFC-143a and a refrigerant selected from the group consisting of HCFC- 22, HFC-125 and a mixture thereof.

Embodiment A6: The method of any of Embodiments A2 - A5, wherein the second refrigerant mixture comprises at least about 40 weight percent HCFC-22, HFC-125 or a mixture thereof.

Embodiment A6a: The method of any of Embodiments A2 - A5, wherein the second refrigerant mixture comprises from about 40 weight percent to about 99 weight percent HCFC-22, HFC-125 or a mixture thereof. Embodiment A7: The method of any of Embodiments A1 - A6, wherein the refrigeration, air conditioning, heat pump or power cycle system comprises a centrifugal compressor and the centrifugal compressor includes an impeller.

Embodiment A8: The method of any of Embodiments A1 - A7, wherein the refrigeration, air conditioning, heat pump or power cycle system comprises a flooded evaporator, a flooded condenser or a combination thereof.

Embodiment A9: The method of any of Embodiments A1 - A8, wherein the average temperature glide remains less than 1°C. Embodiment A9a: The method of any of Embodiments A1 - A8, wherein the average temperature glide remains less than 0.5°C.

Embodiment A9b: The method of any of Embodiments A1 - A8, wherein the average temperature glide remains less than 0.25°C. Embodiment A10: The method of any of Embodiments A1 - A9, wherein the cooling capacity for the system after addition of the second refrigerant remains within 10% of the cooling capacity for the system operating with a full charge of HCFC-22.

Embodiment A10a: The method of any of Embodiments A1 - A9, wherein the cooling capacity for the system after addition of the second refrigerant remains within 7% of the cooling capacity for the system operating with a full charge of HCFC-22.

Embodiment A10b: The method of any of Embodiments A1 - A9, wherein the cooling capacity for the system after addition of the second refrigerant remains within 5% of the cooling capacity for the system operating with a full charge of HCFC-22.

Embodiment A10c: The method of any of Embodiments A1 - A9, wherein the cooling capacity for the system after addition of the second refrigerant remains within 3% of the cooling capacity for the system operating with a full charge of HCFC-22. Embodiment A10d: The method of any of Embodiments A1 - A9, wherein the cooling capacity for the system after addition of the second refrigerant remains within 2% of the cooling capacity for the system operating with a full charge of HCFC-22.

Embodiment A1 1 : The method of any of Embodiments A1 - A10, wherein the impeller tip speed for the centrifugal compressor remains within 10% of the impeller tip speed for the centrifugal compressor in the system operating with a full charge of HCFC-22.

Embodiment A1 1 a: The method of any of Embodiments A1 - A10, wherein the impeller tip speed for the centrifugal compressor remains within 7% of the impeller tip speed for the centrifugal compressor in the system operating with a full charge of HCFC-22.

Embodiment A1 1 b: The method of any of Embodiments A1 - A10, wherein the impeller tip speed for the centrifugal compressor remains within 5% of the impeller tip speed for the centrifugal compressor in the system operating with a full charge of HCFC-22.

Embodiment A1 1 c: The method of any of Embodiments A1 - A10, wherein the impeller tip speed for the centrifugal compressor remains within 3% of the impeller tip speed for the centrifugal compressor in the system operating with a full charge of HCFC-22. Embodiment A1 1 d: The method of any of Embodiments A1 - A10, wherein the impeller tip speed for the centrifugal compressor remains within 2% of the impeller tip speed for the centrifugal compressor in the system operating with a full charge of HCFC-22.

Embodiment A12: The method of any of Embodiments A1 - A1 1 , further comprising adding at least one lubricant.

Embodiment A13: The method of any of Embodiments A1 - A12, wherein the refrigeration, air conditioning, heat pump or power cycle system also contains a first lubricant, the method further comprising replacing at least a portion of the first lubricant with a second lubricant. Embodiment A14: The method of any of Embodiments A1 - A13, wherein the at least one lubricant is chosen from polyol esters, polyvinyl ethers, mineral oils or mixtures thereof.

Embodiment A15: The method of any of Embodiments A1 - A14, wherein the second lubricant is chosen from polyol esters, polyvinyl ethers, mineral oils or mixtures thereof. Embodiment A16: The method of any of Embodiments A1 - A15, wherein the refrigeration, air conditioning, heat pump or power cycle system comprises a refrigerant composition comprising HCFC-22 in an amount ranging from greater than 0 wt% to less than 100 wt% and the second refrigerant in an amount greater than 0 wt% to less than 100 wt%.

Embodiment A17: The method of any of Embodiments A1 - A16, wherein the refrigeration, air conditioning, heat pump or power cycle system comprises a refrigerant composition comprising HCFC-22 in an amount ranging from about 40 wt% to less than 100 wt% and the second refrigerant in an amount greater than 0 wt% to about 60 wt%.

Embodiment A18: The method of any of Embodiments A1 - A17, wherein the refrigeration, air conditioning, heat pump or power cycle system comprises a chiller.

Embodiment A19: The method of any of Embodiments A1 - A18, wherein the refrigeration, air conditioning, heat pump or power cycle system comprises a centrifugal chiller.

Embodiment A20: The method of any of Embodiments A1 - A19, wherein the refrigeration, air conditioning, heat pump or power cycle system comprises a heat pump. Embodiment A21 : The method of any of Embodiments A1 - A20, wherein the refrigeration, air conditioning, heat pump or power cycle system comprises a centrifugal heat pump.

Embodiment A22: The method of any of Embodiments A1 - A21 , wherein the refrigeration, air conditioning, heat pump or power cycle system comprises an organic Rankine cycle system.

Embodiment B1 : A method comprisingrecharging a refrigeration, air conditioning, heat pump or power cycle system containing HCFC-22 with a refrigerant composition comprising at least one refrigerant selected from the group consisting of HFC-143a, HFC-125, and mixtures thereof, and optionally HCFC-22. Embodiment B2: The method of Embodiment B1 comprising recharging a refrigeration, air conditioning, heat pump or power cycle system containing HCFC-22 with a refrigerant composition comprising at least one refrigerant selected from the group consisting of HFC-143a, HFC-125, and mixtures thereof.

Embodiment C1 : A method comprising replacing HCFC-22 in a

refrigeration, air conditioning, heat pump or power cycle system with a refrigerant composition comprising at least one refrigerant selected from the group consisting of HFC-143a, HFC-125, and mixtures thereof, and optionally HCFC-22.

Embodiment C2: The method of Embodiment C1 , comprising replacing HCFC-22 in a refrigeration, air conditioning, heat pump or power cycle system with a refrigerant composition comprising at least one refrigerant selected from the group consisting of HFC-143a, HFC-125, and mixtures thereof.

Embodiment C3: The method of any of Embodiments C1 -C2, wherein the refrigeration, air conditioning, heat pump or power cycle system comprises a centrifugal compressor compressor and the centrifugal compressor includes an impeller. Embodiment C4: The method of any of Embodiments C1 - C3, wherein the impeller tip speed for the centrifugal compressor remains within 10% of the impeller tip speed for the centrifugal compressor in the system operating with a full charge of HCFC-22.

Claims

CLAIMS What is claimed is:

1 . A method comprising:

adding a second refrigerant to a refrigeration, air conditioning, heat pump or power cycle system containing HCFC-22 as a first refrigerant wherein said second refrigerant comprises at least one refrigerant selected from the group consisting of HFC-143a, HFC- 125, and mixtures thereof, and optionally HCFC-22, thus producing a refrigerant composition comprising the first refrigerant and the second refrigerant.

2. The method of claim 1 , wherein the second refrigerant comprises HFC-143a.

3. The method of claim 2, wherein the second refrigerant further

comprises HCFC-22.

4. The method of claim 2, wherein the second refrigerant further

comprises HFC-125.

5. The method of claim 2, wherein the second refrigerant comprises a non-flammable refrigerant mixture of HFC-143a and a refrigerant selected from the group consisting of HCFC-22, HFC-125 and a mixture thereof.

6. The method of claim 5, wherein the second refrigerant mixture

comprises at least about 40 weight percent HCFC-22, HFC-125 or a mixture thereof.

7. The method of claim 1 wherein the refrigeration, air conditioning, heat pump or power cycle system comprises a centrifugal compressor and the centrifugal compressor includes an impeller.

8. The method of claim 1 , wherein the refrigeration, air conditioning, heat pump or power cycle system comprises a flooded evaporator, a flooded condenser or a combination thereof.

9. The method of claim 1 wherein the average temperature glide remains less than 1 °C.

10. The method of claim 1 wherein the cooling capacity for the system after addition of the second refrigerant remains within 10% of the cooling capacity for the system operating with a full charge of

HCFC-22.

1 1 . The method of claim 7, wherein the impeller tip speed for the

centrifugal compressor remains within 10% of the impeller tip speed for the centrifugal compressor in the system operating with a full charge of HCFC-22.

12. The method of claim 1 , further comprising adding at least one

lubricant.

13. The method of claim 1 wherein the refrigeration, air conditioning, heat pump or power cycle system also contains a first lubricant, the method further comprising replacing at least a portion of the first lubricant with a second lubricant.

14. The method of claim 12, wherein the at least one lubricant is chosen from polyol esters, polyvinyl ethers, mineral oils or mixtures thereof.

15. The method of claim 13, wherein the second lubricant is chosen from polyol esters, polyvinyl ethers, mineral oils or mixtures thereof.

16. The method of claim 1 , wherein the refrigeration, air conditioning, heat pump or power cycle system comprises a refrigerant

composition comprising HCFC-22 in an amount ranging from greater than 0 wt% to less than 100 wt% and the second refrigerant in an amount greater than 0 wt% to less than 100 wt%.

17. The method of claim 10, wherein the refrigeration, air conditioning, heat pump or power cycle system comprises a refrigerant

composition comprising HCFC-22 in an amount ranging from about 40 wt% to less than 100 wt% and the second refrigerant in an amount greater than 0 wt% to about 60 wt%.

18. The method of claim 1 , wherein the refrigeration, air conditioning, heat pump or power cycle system comprises a chiller.

19. The method of claim 18, wherein the refrigeration, air conditioning, heat pump or power cycle system comprises a centrifugal chiller.

20. The method of claim 1 , wherein the refrigeration, air conditioning, heat pump or power cycle system comprises a heat pump.

21 . The method of claim 20, wherein the refrigeration, air conditioning, heat pump or power cycle system comprises a centrifugal heat pump.

22. The method of claim 1 , wherein the refrigeration, air conditioning, heat pump or power cycle system is an organic Rankine cycle system.

23. A method comprising:

recharging a refrigeration, air conditioning, heat pump or power cycle system containing HCFC-22 with a refrigerant composition comprising at least one refrigerant selected from the group consisting of HFC-143a, HFC-125, and mixtures thereof, and optionally HCFC-22.

24. A method comprising:

replacing HCFC-22 in a refrigeration, air conditioning, heat pump or power cycle system with a refrigerant composition comprising at least one refrigerant selected from the group consisting of HFC- 143a, HFC-125, and mixtures thereof, and optionally HCFC-22.

25. The method of claim 24, wherein the refrigeration, air conditioning, heat pump or power cycle system comprises a centrifugal

compressor compressor and the centrifugal compressor includes an impeller.

26. The method of claim 25, wherein the impeller tip speed for the