HK1227915A1 - Replacement refrigerant for r22-based refrigeration systems - Google Patents

Abstract

An apparatus and method wherein potential ozone layer-damaging chlorodifluoromethane (Refrigerant R-22) is substituted with a mix of less environmentally damaging refrigerants pentafluoroethane and tetrafluoroethane in chlorodifluoromethane-based air-cooling systems mainly in residential cooling. While less environmentally damaging than chlorodifluoromethane, the substitute refrigerant has a temperature-pressure relationship similar to that of chlorodifluoromethane, making the substitute refrigerant suitable for use with chlorodifluoromethane-based air-cooling systems. In this event, it is mixed with a relatively small percentage of a lubricating oil which is compatible with both the unit refrigerant and typical R-22 system design.

Description

Refrigerant substitute for R-22 based refrigeration systems

The present application is a divisional application of chinese patent application having an application date of 07/03/2006, an application number of 200680054434.3, and an invention name of "refrigerant substitute for R-22 based refrigeration system".

Technical Field

The present invention relates to the replacement of refrigerant R-22 (chlorodifluoromethane) with a mixed refrigerant that is less damaging to the ozone layer in a system designed for refrigerant R-22 (chlorodifluoromethane). More particularly, the present invention relates to an improved refrigerant composition, method and apparatus for refrigeration wherein two refrigerants other than refrigerant R-22 are mixed in a ratio determined such that the temperature-pressure relationship of the mixture approximates the temperature-pressure relationship of refrigerant R-22 (chlorodifluoromethane). This mixture is compatible with refrigerant R-22 (chlorodifluoromethane) so that it can be added to supplement and replace refrigerant R-22 (chlorodifluoromethane). Additional features of the invention relate to improved methods and apparatus for refrigeration wherein a refrigerant mixture is mixed with a soluble lubricating oil to provide lubrication to the apparatus. The lubricant is soluble in the mixture of the present invention and in refrigerant R-22 (chlorodifluoromethane).

Background

Until recently, the R-22 refrigerant chlorodifluoromethane (hereinafter sometimes referred to as "refrigerant R-22 (chlorodifluoromethane)") was also the primary, if not the only, refrigerant used in residential air conditioners, refrigerators, freezers, and window air conditioners. Refrigerant R-22 (chlorodifluoromethane) is a trademark of chlorodifluoromethane by e.i. du Pont de Nemours and Co. The "refrigerant R-22 (chlorodifluoromethane)" used hereinafter in the specification means chlorodifluoromethane of any origin.

However, recently, refrigerant R-22 (chlorodifluoromethane) has come under attack both domestically and internationally as an ozone-depleting chemical. In recent years, refrigerant R-22 (chlorodifluoromethane) has been linked to the destruction of the earth's ozone layer, both domestically and internationally. It is believed that air conditioners, refrigerators/freezers and window air conditioning units containing R-22 will be a source of ozone destroying substances worldwide.

In response to scientific concerns about excessive use of refrigerant R-22 (chlorodifluoromethane) in air conditioning systems and national and global calls, american congress have taken action to first reduce use of refrigerant R-22 (chlorodifluoromethane) in air conditioning units and then prohibit use.

As a first step of eliminating the use of refrigerant R-22 (chlorodifluoromethane) in air-conditioning equipment, congress are gradually eliminating the use of refrigerant R-22 (chlorodifluoromethane) in new facilities from the expiration date to 01/01/2015, and prohibiting the sale of refrigerant R-22 (chlorodifluoromethane) in any size of container until 01/01/2020. The first area to be eliminated for use of refrigerant R-22 (chlorodifluoromethane) was the bakery industry under a partnering program. Another step in the phase out of the use of R-22 was to limit import in 2003, limiting the amount of R-22 that can be imported into the United states.

At the time of this application, refrigerant R-22 (chlorodifluoromethane) was included in most residential window units and chillers used in the United states.

Owners of equipment with refrigerant R-22 (chlorodifluoromethane) based air conditioning units are able to purchase refrigerant levels in their equipment with only the refrigerant licenses required by the clean air act before the sale of large quantities of refrigerant R-22 (chlorodifluoromethane) is prohibited.

Millions of plants containing refrigerant R-22 (chlorodifluoromethane) have been sold in the united states before forced elimination by congress and international society has begun.

Recharging refrigerant R-22 (chlorodifluoromethane) typically involves the typical use of 30 pound tanks or cylinders in the HVAC/R industry. These cylinders were equipped with a distribution outlet that matched a commercially available refrigeration manifold. To recharge the air conditioning system, the customer need only connect the tank or cylinder to the manifold and drain, or "add" refrigerant charge directly to the air conditioning system.

After the congress banned the sale of refrigerant R-22 (chlorodifluoromethane), the owners of millions of installations with refrigerant R-22 (chlorodifluoromethane) -based air conditioning units would have no choice but to seek refrigerant alternatives to service these units. It is currently illegal to mix refrigerants at will according to the standards set forth by the clean air act. An example of such an application is that current R-22 equipment will not be freely mixable with the present invention.

In response to national bans on the use of refrigerant R-22 (chlorodifluoromethane) in air conditioners, after-market distributors have begun to retrofit existing refrigerant R-22 (chlorodifluoromethane) -based air conditioning equipment with new non-R-22 refrigerants such as R410A (a mixture of difluoromethane and pentafluoroethane of 50/50), R417 (a mixture of pentafluoroethane, 1, 1, 1, 2-tetrafluoroethane and butane of 46/50/4), or R407C (a mixture of difluoromethane, pentafluoroethane and 1, 1, 1, 2-tetrafluoroethane of 23/25/52). None of these alternatives contain a lubricant at the time of manufacture.

Refrigerants authorized by the Environmental Protection Agency (EPA) to replace refrigerant R-22 (chlorodifluoromethane) in air conditioners are currently under scrutiny and will evolve to require an environmentally safe refrigerant with a 0odp factor like the present invention described herein. Unfortunately, most R-22 alternatives have a significantly different temperature-pressure relationship with the refrigerant R-22 chlorodifluoromethane) at most operating temperatures.

Because of the difference in temperature-pressure relationships between refrigerant R-22 (chlorodifluoromethane) and current refrigerant alternatives, existing refrigerant R-22 (chlorodifluoromethane) -based systems are typically not interchangeable. Thus, there is a need for a refrigerant that can meet the system design needs, while also meeting EPA and international social needs, for a non-retrofit refrigerant R-22 (chlorodifluoromethane) based plant.

Simply mixing the refrigerant with the existing refrigerant R-22 (chlorodifluoromethane) to supplement or "complete" this level is legally and impracticably violated. When other refrigerants are mixed with refrigerant R-22 (chlorodifluoromethane), the mixture may have pressure characteristics of substances that may be harmful to the plant or the operator. This temperature-pressure relationship differs significantly from that of R-22 (chlorodifluoromethane) over the normal refrigerant operating temperature range and at temperatures at which R-22 is typically used.

Thus, in the absence of refrigerant R-22 (chlorodifluoromethane), the owner of an air-conditioning unit fitted with R-22 (chlorodifluoromethane) is faced with only one option: when their level of air conditioning coolant is low, professional service-removes the existing refrigerant R-22 (chlorodifluoromethane) at considerable expense and refurbishes the system to be compatible with some types of refrigerant gases.

R-22 refrigerant was developed to replace the previous, now prohibited R-12 refrigerant or dichlorodifluoromethane. R-12 is sometimes referred to as FREONThis is a trademark of dichlorodifluoromethane by e.i. du Pont de Nemours and co.

Thomas et al (U.S. patent No. 5254280) disclose lubricants developed for use with known refrigerants, such as R134a (1, 1, 1, 2-tetrafluoroethane), and combinations of the lubricants with refrigerants, as alternatives to R-12. The lubricant comprises polyoxyalkylene glycols which are hydrophilic and may damage the system as discussed below.

Wilczek (U.S. Pat. No. 5384057), Gorski (U.S. Pat. No. 4971712), and DuPont Anton (U.S. Pat. No. 5145594) disclose other R-12 substitutes in the form of certain synthetic lubricant blends in various R134a and R134a/R125 refrigerant systems. The DuPont company patent discusses a known gas known as R125 (pentafluoroethane). R125 is five fluorine atoms bonded to one ethane molecule. This is a very large molecule for refrigerants. Are currently only produced for refrigeration. Anton discloses the use of a lubricant comprising at least one cyanocarbon compound. Wilczek discloses fluorosilicones as lubricants. Gorski discloses polyalkylene glycols as lubricants.

Systems containing R-22 or R-12 substitutes are still being produced today. These older systems have a common component: r-22, R-22 mineral oil lubricant and water sequestered into the desiccant. If R134a (1, 1, 1, 2-tetrafluoroethane) is added to the system, it will destroy the system as follows: (1) if lubricant is not added to R134a (as in Tamura et al, U.S. Pat. No. 4,953,312), the R-22 system would be in urgent need of lubricating oil, since R134a gas is not miscible with mineral oil lubricants; (2) if synthetic lubricating oil is added to R134a (as in Thomas et al), a different problem arises-a humidity problem. Older systems were able to trap water into their dryers. These synthetic lubricants (e.g., polyethylene glycol-based or silicone-based lubricating oils) are hydrophilic. Thus, they are not only miscible with R-22 and R134 a; they are also partially or fully miscible with water. Thus, if they are introduced into the R-22 system, they will push water out of the dryer into the refrigerant stream, beginning to corrode and destroy the pressure switches, TX valves, and possibly other system components. This is why elf atochem and DuPont, to name a few, disclose detailed rinsing procedures and efficient dryer change outlets to prevent damage to the cooling system.

Weber (U.S. patent No. 5942149) also discloses another R-12 replacement consisting of a mixture of chlorodifluoromethane, tetrafluoroethane and naphthalene lube oils.

Disclosure of Invention

The invention discloses a method and equipment for replacing (chlorodifluoromethane) of a refrigerant R-22 to be used as the refrigerant, which are harmless to the environment. More particularly, the present invention provides a mixture of at least two refrigerants that are miscible with each other and compatible with refrigerant R-22 (chlorodifluoromethane) while having a temperature-pressure curve similar to that of refrigerant R-22 (chlorodifluoromethane) over the operating range of ambient temperatures typically experienced by air conditioning equipment or other devices utilizing refrigerant R-22 (chlorodifluoromethane) as a refrigerant. The present invention also provides a lubricant that is compatible with both the environmentally benign refrigerant of the present invention and refrigerant R-22 (chlorodifluoromethane) such that the refrigerant mixture and refrigerant R-22 (chlorodifluoromethane) according to the present invention can be used with the lubricant in a refrigeration system without deleterious effects when parts of the refrigeration equipment requiring lubrication are located remotely from the refrigerant.

More particularly, the refrigerants and methods disclosed herein relate to mixtures of pentafluoroethane and tetrafluoroethane in specific ratios that provide a temperature-pressure relationship approximating that of refrigerant R-22 (chlorodifluoromethane) over a range of ambient temperature operating conditions for the refrigerant in which refrigerant R-22 (chlorodifluoromethane) is useful. The pentafluoroethane and/tetrafluoroethane refrigerant blends disclosed herein are compatible with synthetic and mineral oils. The tetrafluoroethane may be 1, 1, 1, 2-tetrafluoroethane or 1, 1, 2, 2-tetrafluoroethane. In an exemplary embodiment, the refrigerant according to the present invention comprises a ratio of about 40 to 45 weight percent tetrafluoroethane to about 55 to about 60 percent 1, 1, 1, 2-pentafluoroethane, based on the total weight of pentafluoroethane and 1, 1, 1, 2-tetrafluoroethane. In another exemplary embodiment, the refrigerant comprises a proportion of about 42 weight percent tetrafluoroethane to about 58 weight percent 1, 1, 1, 2-pentafluoroethane.

In addition, the refrigerant according to the present invention further comprises from about 0 to about 20% by weight (based on the total weight of pentafluoroethane and 1, 1, 1, 2-tetrafluoroethane) of a lubricating oil soluble in chlorodifluoromethane, pentafluoroethane, and 1, 1, 1, 2-tetrafluoroethane. In a preferred embodiment, the lubricating oil is present in the range of about 0.5 to about 2 weight percent of the refrigerant mixture.

In an exemplary embodimentWherein the lubricating oil is a naphthyl or paraffin-based lubricating oil. In another exemplary embodiment, the lubricant is selected from those of Andersol, East Hanover, N.J., a subsidiary of Royal Lubricant, Inc., to name a few2302 brand of lubricant.2302 is a naphthalene oil lubricant having the following composition:

65-85% of the hydrotreated light naphthalene is distilled,

10-20% of solvent refined light naphthalene distilled petroleum,

butylated triphenyl phosphate < 0.5%, and

less additives < 2%.

In another exemplary embodiment, the lubricating oil may be a synthetic lubricating oil or a mixed oil that is readily soluble in a mixture of chlorodifluoroethane and tetrafluoroethane. A suitable synthetic lubricating oil is an artificially manufactured, synthetic alkyl aromatic lubricant. Suitable synthetic lubricating oils include alkylated benzene lubricants.

The lubricant may be either a synthetic alkyl aromatic lubricant, such as alkylbenzene alone, or a mixture of a synthetic alkyl aromatic lubricant and mineral oil or a mixture of a synthetic alkyl aromatic lubricant and polyol ester (POE). When so mixed, preferably, but not necessarily, a minor portion of the mixture is mineral oil or POE. By minor portion is meant less than 50% by weight of the blended refrigerant. Alternatively, mineral oil or polyol ester (POE) may be used alone.

When trying to use the refrigerant substitute according to the invention for replacing the refrigerant R-22 (chlorodifluoromethane) that has been discharged from the device, the refrigerant substitute of the invention can also be used for a complete recharge of a device designed for use with the refrigerant R-22 (chlorodifluoromethane) because the temperature-pressure curve of the refrigerant is close to that of the refrigerant R-22 (chlorodifluoromethane). Thus, when the refrigerant is used as a complete replacement for refrigerant R-22 (chlorodifluoromethane), it is no longer necessary that the lubricant be compatible with chlorodifluoromethane, but only with 1, 1, 1, 2-tetrafluoroethane and pentafluoroethane.

Further, the refrigerant substitute of the present invention is less harmful to the ozone layer than the refrigerant R-22 (chlorodifluoromethane), and is useful in air-conditioning equipment, particularly residential air-conditioning equipment, without being limited to these uses. In fact, the refrigerant can be used as a substitute or replacement for refrigerant R-22 (chlorodifluoromethane) in almost any application, thereby precluding the use of ozone-depleting refrigerant R-22 (chlorodifluoromethane).

In further detail, the invention provides a cartridge containing a mixture of tetrafluoroethane and pentafluoroethane with naphthalene oil which may be fitted with an outlet manifold matching the R-22 (chlorodifluoromethane) recharge manifold of the refrigerant. The recharging manifold is typically used to recharge an apparatus having the latter refrigerant. Refrigerant is then allowed to flow from the tank through the manifold and into the plant to replace refrigerant R-22 (chlorodifluoromethane) refrigerant, which refrigerant R-22 has been lost from the refrigeration system.

When mixing the components of the refrigerant mixture of the present invention, the lubricant should first be mixed with tetrafluoroethane and then this mixture mixed with pentafluoroethane in the proportions mentioned above. Otherwise, the product cannot be properly mixed.

In exemplary forms, the lubricant has a viscosity of from 5 to 500 centistokes, more preferably from 5 to 100 centistokes, even more preferably from 5 to 50 centistokes, most preferably from 5 to 10 centistokes. Lubricants having 5 to 10 centistokes are preferred.

In exemplary embodiments, the weight percent of lubricant in the refrigerant blend is from 0 to 20%, preferably from 0.5 to 2%, more preferably from 1 to 2%, even more preferably from 1.25 to 2%, and most preferablyThe selection is 1.5-1.75%. The weight percentage of lubricant in the refrigerant blend is, for example, 1.75 ± 0.05%. Suitable lubricants are severely hydrotreated naphthalene/paraffin lubricants, as mentioned above2302. Other suitable lubricants include Sunpar R2280 (a paraffin-based lubricant) from The company of The shurieve chemical, The Woodlands, Texas, Lubrizol 403, Sunthene 2001 (a naphthyl lubricant) and L30 or L35 or Zerol from Nu-Calgon wheatale, inc. Mobil No. 1, 5-weight synthetic oil (which is hydrophobic) can also be used as a lubricant, but it is relatively expensive.

For the components of the refrigeration system to function best, 0.5-20% of the total weight of the refrigerant should be lubricant. When adding the refrigerant blend to a refrigeration system, one should leave lubricant in the system if one were to take out refrigerant R-22 for some reason.

The lubricant in the system of the present invention is miscible with pentafluoroethane and tetrafluoroethane blends and with R-22 refrigerants. This will allow the residual R-22 refrigerant to mix with the refrigerant of the present invention without releasing a significant amount of moisture remaining in the dryer and without subsequent damage to the system (which would occur if the synthetic lubricants disclosed in Thomas et al and DuPont patents were used). The alkylbenzene alone is not considered miscible with tetrafluoroethane (especially Rl 34a) and is well soluble in the current tetrafluoroethane/chlorodifluoroethane mixture. This solubility allows the refrigerant blend alternative to lubricate the system, preventing damage to the compressor and system components.

Various optional additives may be included in the lubricant. Corrosion inhibitors may be included (otherwise corrosion may occur within 6 months). Exemplary corrosion inhibitors are those used in anhydrous systems (such corrosion inhibitors include calcium or phosphate salts). The corrosion inhibitor may be bonded to a lubricant. In addition, surfactants and/or foaming agents may be included.

Current refrigerant blends are designed to be used as a replacement for R-22 in refrigeration systems. It is designed as a replacement where little or no modified components are used to adapt the system for use with the refrigerant of the present invention.

Current refrigerant blends can be used as a replacement for R-22 refrigerants, typically at minimum without retrofitting air conditioning systems or flushing out. It is recommended that a complete vacuum be obtained before the inventive refrigerant is added.

Drawings

Many aspects of the disclosure can be better understood with reference to the following drawings.

FIG. 1 shows the pressure-temperature curve of various blends disclosed in this invention compared to R-22.

FIG. 2 compares the temperature-enthalpy curve of an exemplary disclosed embodiment of the present invention with R-22.

Detailed Description

The present invention provides a mixture of non-refrigerants 22 that is less damaging to the earth's ozone layer and is approved for use in air conditioning by the U.S. environmental protection agency. The inventive mixtures are compatible with refrigerant R-22 (chlorodifluoromethane) and can be used to replace refrigerant R-22 (chlorodifluoromethane) in existing R-22 based refrigeration systems. It is anticipated that the present invention will gradually replace refrigerant R-22 (chlorodifluoromethane) in refrigerant R-22 (chlorodifluoromethane) based air cooling systems without the need to retrofit existing refrigerant R-22 (chlorodifluoromethane) based systems for refrigerant substitutes other than refrigerant 22.

In particular, current refrigerant blends include a mixture of pentafluoroethane and tetrafluoroethane provided at a pressure in a tank or cylinder equipped with an outlet matched to an existing refrigerant R-22 (chlorodifluoromethane) recharging tool manifold, packaged with a compatible lubricating oil, such that the refrigerant and lubricating oil mixture can be added to an existing refrigerant R-22 (chlorodifluoromethane) -based coolant system. Furthermore, the invention offers the possibility of using a new refrigerant system, originally designed for "refrigerant R-22 (chlorodifluoromethane), which by supplying a modified EPA refrigerant makes retrofitting unnecessary for new plant applications.

In an exemplary embodiment, the present invention provides a cylindrical canister such as a standard 25 pound or 30 pound canister that has previously been used to contain "refrigerant R-22 (chlorodifluoromethane)" but which contains about 42 weight percent 1, 1, 1, 2-tetrafluoroethane and about 58 weight percent pentafluoroethane. The tank also contains a preferred lubricant in a solution with 0.5% -2% by weight of a coolant mixture2302。

Existing refrigerant R-22 (chlorodifluoromethane) based air conditioning systems use a quantity of vegetable or hydrocarbon mineral oil to lubricate the compressor. The oil has a very low vapor pressure and is insoluble in pure tetrafluoroethane, especially 1, 1, 1, 2-tetrafluoroethane. Therefore, the addition of tetrafluoroethane to replace the refrigerant R-22 (chlorodifluoromethane) in the existing refrigerant R-22 (chlorodifluoromethane) -based air conditioning system results in compressor failure due to lack of adequate lubrication. The present invention provides a lubricating oil which is compatible with the mixture of tetrafluoroethane and pentafluoroethane of the present invention and "R-22 (chlorodifluoromethane) of a refrigerant" and is suitable for lubricating refrigerant compressors and other air-conditioning constituent parts. On the other hand, the lubricating oils disclosed herein are readily soluble in tetrafluoroethane/pentafluoroethane mixtures. This solubility allows the refrigerant blend substitute to lubricate the air conditioning system, preventing damage to the compressor and system components.

Example 1

Table 1 summarizes the 2% by weight of a refrigerant mixture of 58/42% by weight pentafluoroethane and 1, 1, 1, 2-tetrafluoroethaneSolubility test results for 2302 oil lubricant solutions. Will be provided with2302 oil (subordinate from Royal Lubricant Co., Ltd.)Company) was added to a clean Fisher-Porter pressure tube and an 58/42 ratio mixture of pentafluoroethane/1, 1, 1, 2-tetrafluoroethane was introduced under pressure to maintain the liquid state.

TABLE 1

Note: the color of the fluid remained the same when the dropper was emptied. The vented gases deposited oil on the test panel.

Example 2

1, 1, 1, 2-tetrafluoroethane and pentafluoroethane were mixed with a naphthalene oil lubricant in such proportions that the temperature-pressure curve of the mixture was similar to that of refrigerant R-22 (chlorodifluoromethane) in the normal operating range of the air conditioner. Table 2 summarizes the results of temperature-pressure curve testing of various mixtures of 1, 1, 1, 2-tetrafluoroethane and pentafluoroethane at normal air conditioning operating temperatures in the range of-60 ° F to 160 ° F.

For table 2, different weight percentages of 1, 1, 1, 2-tetrafluoroethane and pentafluoroethane were mixed with the lubricant to show the pressure temperature relationships for the different inventive combinations.

Figure 1 shows the pressure (liquid) -temperature curves for pentafluoroethane and tetrafluoroethane blends of R-22 and 60/40, 55/45 and 58/42, respectively.

Figure 2 shows the temperature-enthalpy curve for 60/40 blends of pentafluoroethane and tetrafluoroethane compared to R-22.

The blends of tetrafluoroethane and pentafluoroethane refrigerants disclosed in this invention exhibit the following characteristics:

dew point is-32F

The bubble point is-41.5F

The sliding point is 9.5F

An exemplary refrigerant blend is about 58 weight percent pentafluoroethane and about 42 weight percent 1, 1, 1, 2-tetrafluoroethane. This is the ratio of pentafluoroethane to 1, 1, 1, 2-tetrafluoroethane and the mixtures and lubricants of the invention show the greatest degree of similarity to "refrigerant R-22 (chlorodifluoromethane)" at most operating temperatures.

The apparatus and method of the preferred embodiment includes the use of a mixture of 1, 1, 1, 2-tetrafluoroethane and pentafluoroethane in the ranges discussed above in operating an air conditioning system in combination with from about 0.5% to about 2% by weight of the lubricating oil discussed above, wherein the cooling oil mixture replaces refrigerant R-22 (chlorodifluoroethane) in a refrigerant R-22 (chlorodifluoroethane) -based refrigeration system.

The process and apparatus in the preferred embodiment provides the pentafluoroethane/1, 1, 1, 2-tetrafluoroethane mixture and lubricating oil described above in a 30 pound cylinder which is pressure sealed and fitted with an outlet matching the existing refrigerant 22 type refrigeration manifold, typically a 1/4 inch convex flare.

Furthermore, it should be noted that the system tested during the test ran more smoothly and the compressor showed lower vibration when the mixture of the invention was added. It is theorized that the lubricating oil is readily soluble in the refrigerant gas, which is capable of better lubricating the compressor and reciprocating components than the refrigerants used in the existing refrigerant R-22 (chlorodifluoromethane) itself. It may also be noted that power losses are reduced in some applications.

The refrigerants of the present invention may also be used as a refrigerant replacement for new R-22 air conditioning systems, such as systems used in current HFC-less equipment.

The invention disclosesThe 2302 naphthalene oil lubricant has a flash point in excess of 150 ° F. Pure refrigerant 1, 1, 1, 2-tetrafluoroethane is not miscible with naphthalene lubricants like mineral oil or mineral fur seal oil (both of which can be used as lubricants in the present invention). Pentafluoroethane is miscible with most naphthalene lubricants, including mineral oils. The presence of pentafluoroethane allows the use of mineral oils (forming a clear, partially miscible blend) in the refrigerant blends and systems of the invention. The lubricant may advantageously be partially polymerized into longer chain molecules to allow it to function at very low percentage levels. The lubricant may be hydrogenated or polymerized for stability and wear resistance.

The phosphated additive increases corrosion resistance and improves wear resistance in the presence of acids and salts. Calcium additives help lubricants resist rust and corrosion effects; the calcium salt reduces the corrosive effects of hydrochloric acid formed in the presence of water and chlorinated gases in the refrigerant system of the present invention.

As mentioned aboveThe lubricant contains the aforementioned corrosion inhibitor and may also contain an acrylic polymer. It is believed that the function of the acrylic polymer is to increase the abrasion resistance under harsh conditions. The acrylic resin may assist in forming the film, as well as assist in coating the lubricant onto the metal, softening the part, and staying thereCapability.

Blends of the lubricants of the present invention with R-22, R-22 lubricants, and the refrigerant gases of the present invention are miscible.

It is to be understood that variations and modifications can be made to the invention taught herein and those are within the scope and spirit of the invention as taught above and claimed below.

TABLE 2

Claims (20)

1. In an apparatus designed for use with chlorodifluoromethane refrigerant, the improvement comprising replacing chlorodifluoromethane with a mixed refrigerant substitute containing a lubricant,

the refrigerant substitute comprises:

from about 40% to about 45% by weight tetrafluoroethane and from about 55% to about 60% by weight pentafluoroethane;

the refrigerant replacement is packaged with about 0% to about 20% by weight of the refrigerant of a lubricant comprising readily soluble chlorodifluoromethane, pentafluoroethane, and tetrafluoroethane.

2. The apparatus of claim 1, said lubricating oil having the following composition:

65-88% of a hydrotreated light naphthalene distillate, and

10-20% of solvent refined light naphthalene distilled petroleum.

3. The apparatus according to claim 1 wherein in said refrigerant substitute, said tetrafluoroethane is present in a proportion of about 40% by weight, as compared to said pentafluoroethane present in an amount of about 60% by weight.

4. The apparatus according to claim 1 wherein in said refrigerant substitute, said tetrafluoroethane is present in a proportion of about 42% by weight, as compared to said pentafluoroethane present in an amount of about 58% by weight.

5. The apparatus according to claim 1 wherein in said refrigerant substitute, said tetrafluoroethane is present in a proportion of about 45% by weight, as compared to said pentafluoroethane present in an amount of about 55% by weight.

6. A method for recharging equipment designed for use with chlorodifluoromethane refrigerant, the method comprising:

(1) providing a refrigerant substitute under pressure in a cylindrical tank fitted with an outlet matching the chlorodifluoromethane feed manifold of the apparatus; and

(2) adding a refrigerant replacement to the apparatus via the manifold in place of chlorodifluoromethane, wherein the refrigerant replacement comprises:

about 40% to about 45% by weight tetrafluoroethane; and

from about 55% to about 60% by weight of pentafluoroethane;

the refrigerant replacement is packaged with lubricating oil which is readily soluble in chlorodifluoromethane, pentafluoroethane, and tetrafluoroethane in an amount of from about 0% to about 20% by weight of the refrigerant.

7. The method of claim 6, said lubricating oil having the following composition:

65-85% of hydrotreated light naphthalene distillate,

10-20% of solvent refined light naphthalene distilled petroleum.

8. The process according to claim 6 wherein in said refrigerant substitute, said tetrafluoroethane is present in a proportion of about 40% by weight, as compared to said pentafluoroethane present in an amount of about 60% by weight.

9. The process according to claim 6 wherein in said refrigerant substitute, said tetrafluoroethane is present in a proportion of about 42% by weight, as compared to said pentafluoroethane present in an amount of about 58% by weight.

10. The process according to claim 6 wherein in said refrigerant substitute, said tetrafluoroethane is present in a proportion of about 45% by weight, as compared to said pentafluoroethane present in an amount of about 55% by weight.

11. A refrigerant, comprising:

about 40% to about 45% by weight tetrafluoroethane; and about 55% to 60% by weight of pentafluoroethane, said refrigerant substitute being packaged with lubricating oil which is readily soluble in chlorodifluoromethane, pentafluoroethane and tetrafluoroethane in an amount of about 0% to about 20% by weight of said refrigerant.

12. A refrigerant according to claim 11, said lubricating oil having the following composition:

65-85% of hydrotreated light naphthalene distillate, and 10-20% of solvent refined light naphthalene distilled petroleum.

13. The refrigerant according to claim 11 wherein said tetrafluoroethane is present in the proportion of about 40% by weight, in contrast to said pentafluoroethane being present in an amount of about 60% by weight.

14. The refrigerant of claim 11 wherein said tetrafluoroethane is present in the range of about 45% by weight and said pentafluoroethane is present in the range of about 55% by weight with a naphthalene lube.

15. The refrigerant according to claim 11 wherein said tetrafluoroethane is present in the proportion of about 40% by weight, as compared to said pentafluoroethane present in an amount of about 60% with a naphthalene lube.

16. The invention according to any one of claims 1, 6 and 11, wherein the tetrafluoroethane is 1, 1, 1, 2-tetrafluoroethane.

17. The invention according to any one of claims 2, 7 and 12, wherein the lubricating oil further comprises an acrylic polymer or a corrosion inhibitor or both.

18. The invention according to any one of claims 1, 6 and 11, wherein the lubricating oil is selected from the group consisting of naphthyl lubricants, paraffin-based lubricants and mixtures thereof, synthetic alkyl aromatic lubricants mixed with mineral oil, synthetic alkyl aromatic lubricants mixed with polyol esters, mineral oil and polyol esters.

19. The invention according to any one of claims 1, 6, and 11, wherein the synthetic alkyl aromatic lubricant comprises an alkylbenzene.

20. The invention according to claim 1 or 6, wherein the device is selected from the group consisting of a refrigeration unit, an air conditioning unit, and an HVAC unit.