RU2235749C2 - Cooling agent composition - Google Patents

Abstract

FIELD: special-destination fluids.

SUBSTANCE: agent intended for use in cooling systems, in particular in air-conditioning systems, contains 83-99% 1,1,1,2-tetrafluoroethane, 1-17% pentafluoroethane, and an additive selected from saturated hydrocarbons and their mixtures boiling within a temperature range from -5 to +70^оС, preferably from pentane, isopentane, cyclopentane, and their mixtures. Advantageously, percentage of additives ranges from trace to 10% and more preferably from 1 to 8%.

EFFECT: reduced inflammability and increased miscibility resulting in better return of lubricant into system allowing replacement of environmental dangerous constituents.

12 cl, 2 dwg, 9 tbl, 7 ex

Description

This invention relates to a refrigerant, in particular, but not exclusively, for air conditioning systems. This system is particularly associated with compositions of refrigerants that do not adversely affect the atmospheric layer of ozone, and compositions that can be added to existing refrigerants that are compatible with lubricants commonly used in refrigeration and air conditioning systems. The present invention also relates to a method for modifying cooling and air conditioning systems.

Chlorofluorocarbons (CFC), such as CFC11 and CFC12, are stable, have low toxicity and are non-flammable, provide low-hazard working conditions and are used in refrigeration and air conditioning systems. Upon release, they penetrate the stratosphere and attack the ozone layer, which protects the environment from the dangerous effects of ultraviolet rays. The Montreal Protocol, an international environmental agreement signed by more than 160 countries, requires the gradual exclusion of CFC according to the adopted program. Now this also applies to chlorofluorocarbons (HCFCs), which also have a harmful effect on the ozone layer.

Any CFC12 substitutes should not deplete the ozone layer. The compositions of this invention do not include chlorine atoms and, therefore, they will not have a depleting effect on the ozone layer, while at the same time providing similar behavior with CFC12 as a working fluid in refrigeration units.

Various terms are used in the patent literature to describe mixtures of refrigerants. They can be defined as follows.

Zeotrop: a liquid mixture in which the composition of the vapor and liquid phase at a given temperature are different.

Temperature shift: if a mixture of liquids, in which the composition of the vapor and liquid phase at a given temperature is different, is distilled at constant pressure, its boiling point will increase. The change in boiling point from the moment the distillation begins to the point where the liquid phase has almost disappeared is called the temperature shift. A shift is also observed if the saturated vapor of such a mixture condenses at constant pressure.

Azeotrope: A liquid mixture of a specific composition in which the vapor and liquid phase compositions are the same at a specific temperature. Strictly speaking, a liquid mixture that is an azeotrope, for example, in an evaporator, cannot also be an azeotrope in a condenser. However, literature on refrigeration can describe a mixture as azeotropic if it meets the above definition at any temperature in the range of the operating range.

A mixture close to the azeotrope: a mixture that boils in a small temperature range, that is, has a small temperature shift.

Mixture - refrigerant modifier: a chlorine-free mixture used to completely replace the original CFC or HCFC refrigerant.

Mixture - refrigerant diluent: A chlorine-free mixture added during maintenance to the CFC or HCFC refrigerants left in the system, i.e. the refrigerant topped up to compensate for the leak.

Sealed Compressor: A compressor in which the electric motor is located in the same completely sealed enclosure as the compressor. The engine is cooled by refrigerant vapor returning to the compressor. Heat generated by the motor is removed through a condenser.

Semi-hermetic compressor: similar to hermetic compressor; the main difference is that the casing has a bolted connection that can be opened, which makes it possible to service the engine and compressor.

Open compressor: a compressor that is driven by an external motor through a drive shaft passing through the compressor housing. Heat from the engine is dissipated directly in the environment, not through a condenser. This results in slightly more efficient operation than a hermetic compressor, but refrigerant leakage may occur on the shaft seal.

The percentages and proportions referred to in this description are mass, unless otherwise indicated. Percentages and proportions are selected so as to total 100%.

According to a first aspect of the invention, the composition of the refrigerant comprises 1,1,1,2-tetrafluoroethane (R134a), pentafluoroethane (R125) and an additive selected from saturated hydrocarbons or a mixture thereof, boiling in the range from -5 to + 70 ° C; while the mass content of R125 and R134a is in the range: R125 1-17%, R134a 99-83%.

The preferred mass content of R125 and R134a is in the range of: R125 2-15%, R134a 98-85%.

Piston type compressors, that is, reciprocating or rotary compressors used in refrigeration systems, absorb small amounts of lubricant from the crankcase, which is discharged with refrigerant vapor through the exhaust valves. In order to maintain compressor lubrication, this oil must be guided along the refrigerant stream and returned to the crankcase. CFC and HCFC refrigerants mix with hydrocarbon lubricants and therefore transfer the lubricant along the circuit. However, HFC refrigerants and hydrocarbon lubricants have low mutual solubilities, therefore, an effective return of the lubricant is not possible. This problem is especially acute in evaporators, where low temperatures can increase the viscosity of oils so much that they prevent their transfer along the walls of the pipeline. In the case of CFC and HCFC, a sufficient amount of refrigerant remains in the lubricant to reduce viscosity and allow the lubricant to return.

When using HFC with hydrocarbon greases, the return of grease can be facilitated by the introduction of a hydrocarbon fluid having the following properties into the system:

(a) sufficient solubility in the lubricant at the evaporator temperature to reduce its viscosity; and

(b) sufficient volatility to allow distillation from the hot grease in the compressor crankcase.

Hydrocarbons meet these requirements.

Preferred hydrocarbon additives are selected from the group consisting of 2-methylpropane, 2,2-dimethylpropane, butane, pentane, 2-methylbutane, cyclopentane, hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane and methylcyclopentane. Preferred is the use of n-pentane, cyclopentane, isopentane and mixtures thereof. Particularly preferred is the use of n-pentane or isopentane, or mixtures thereof.

In particularly preferred embodiments of the invention, a mixture of pentane, preferably n-pentane, isopentane, or a mixture thereof, is used together with butane. This provides the advantage that a near boiling or almost azeotropic mixture can be obtained so as to avoid the formation of a flammable high pentane content in the event of a leak, for example, from a storage vessel.

The amount of hydrocarbon additive may be up to 10%, preferably from 1 to 8%, more preferably about 2-4%. The amount of R125 can be increased with increasing hydrocarbon content.

The relative contents of the pentane and butane components can be selected so as to give a total of from 0.2 to 5% of the composition, preferably from 2 to 4%, more preferably from 3 to 4%. A pentane (preferably isopentane) content of 0.2 to 2% can be used together with an appropriate amount of 4.8 to 3% butane in formulations containing a total of 5% hydrocarbon. In formulations with a hydrocarbon content of less than 5%, for example 1 to 4%, relatively large butane: pentane ratios can be used to minimize hydrocarbon buildup during leakage. This reduces the risk of ignition.

A particularly preferred composition includes,%: R125 9.5%, R134a 88.5, pentane 2.

Another composition includes,%: R125 5, butane / pentane mixture from 3 to 4, R134a residue up to 100.

A pentane: butane ratio of from 1: 3 to 1: 8, preferably about 1: 5, can be used.

The compositions of the refrigerants of this invention provide several advantages. The presence of R125 lowers the flammability of the refrigerant mixture. A higher HFC content makes it possible to add more pentane to the mixture, which reduces the solubility of the mixture with traditional lubricants, such as mineral and alkylbenzene oils.

The present invention can provide several advantages over R12, including a lower inherent overall warming potential and lower discharge temperature. The present invention can provide several advantages over pure R143a, including higher miscibility and higher loading of hydrocarbon oils and therefore better oil return.

The invention will now be described by way of examples without limiting meaning.

EXAMPLE 1

R125 / R134a / pentane formulations were evaluated using a standard refrigeration cycle analysis method to evaluate their suitability as R12 modifiers in sealed and semi-hermetic systems. The operating conditions selected for analysis are typical of the operating conditions of cooling systems. Since these mixtures, strictly speaking, had different compositions of the liquid and vapor phases, the average values of their temperature displacements in the evaporator and condenser were chosen as the limiting temperatures of the cycle. The same temperatures were used to obtain data on the behavior of R12.

Pentane was present in an amount of 4 wt.% Based on the total weight of the mixture R125 / R134a. To simplify the calculations, this small amount of pentane was not taken into account.

Formulations containing 1 to 15% R125 were considered.

In the analysis, the following cycle conditions were used:

EVAPORATOR

The average temperature of evaporation of the liquid 7.0 ° C

Superheat 5.0 ° С

Pressure drop across the suction line (in temperature units)

saturation) 1.5 ° C

CAPACITOR

The average liquid condensation temperature of 45.0 ° C

Subcooling 5.0 ° C

Pressure drop across the discharge line (in units of temperature)

saturation) 1.5 ° C

HEAT EXCHANGER LIQUID LINE / SUCTION LINE

Efficiency 0.3

COMPRESSOR

Motor efficiency 0.85

Isoentropic compressor efficiency 0.7

Compressor volume factor 0.82

SPARK LOADS

0.3 kW internal fan

External fan 0.4 kW

Monitoring devices 0.1 kW

The results of the analysis of the operation of the air conditioning unit when using these operating conditions are shown in Table 1, and the key parameters are built in figure 1.

All mixtures have lower discharge temperatures than R12, and therefore, in this regard, satisfy the requirements of these specifications.

The system refrigeration coefficient (COP) is at least 97% of this value for R12. The cooling capacity of all formulations was more than 90% of this value for R12 in the entire dilution range.

Compositions containing 3% or more of R125 had a cooling capacity of more than 95% of that for R12. Compositions containing 12% or more of R125 had a higher cooling capacity than R12.

The discharge pressure did not exceed this value for R12 by more than 0.2 MPa (2 bar) for all compositions.

All formulations satisfy the requirements of this invention. Compositions with R125 contents of 9 to 13% are particularly promising, providing a good compromise between discharge pressure and cooling capacity.

EXAMPLE 2

R125 / R134a / pentane formulations were evaluated using a standard refrigeration cycle analysis method to evaluate their potential as an R12 modifier in mobile air conditioning systems (PACS). The operating conditions selected for analysis are typical of PMSC systems. Since the mixtures, strictly speaking, had different compositions of the liquid and vapor phases, the average displacement temperatures in the evaporator and condenser were chosen to determine the temperature boundaries of the cycle. The same temperatures were used to obtain data on the behavior of R12.

Pentane was present in an amount of 4 wt.% Based on the total weight of the mixture R125 / R134a. In order to simplify the calculations, this small amount of pentane was not taken into account.

Formulations containing 1 to 17% R125 were considered. In the analysis, the following cycle conditions were used:

EVAPORATOR

The average temperature of evaporation of the liquid 7.0 ° C

Superheat 5.0 ° С

Pressure drop across the suction line (in units)

saturation temperature) 1.5 ° C

CAPACITOR

The average liquid condensation temperature of 60.0 ° C

Subcooling 5.0 ° C

Pressure drop across the discharge line (in units)

saturation temperature) 1.5 ° C

COMPRESSOR

Isoentropic compressor efficiency 0.7

Compressor volume factor 0.82

SPARK LOADS

Condenser fan 0.4 kW

The results of the analysis of the operation of the air conditioning unit when using these operating conditions are shown in Table 2, and the key parameters are built in figure 2.

All mixtures have lower discharge temperatures than R12, and, therefore, from this point of view satisfy the requirements of these specifications.

The cooling capacity of all compositions is higher than this value for R12, in the entire range.

Compositions containing up to 3% R125 have a discharge pressure that does not exceed the corresponding value for R12 by more than 0.2 MPa (2 bar).

For high cooling capacities in equipment that can withstand higher pressures, a composition with 5-17% R125 is preferred, and particularly preferred with 10-17%.

If maximum pressure is of interest, mixtures containing from 0 to 3% R125, which increase the cooling capacity but do not exceed the pressure of R12 by more than 0.2 MPa (2 bar), are preferred. These mixtures are close to azeotropic mixtures.

EXAMPLE 3

R12 and several R134a / pentane formulations were tested in a typical cooling system to evaluate (a) the minimum amount of pentane needed in R134a to ensure adequate oil return when using mineral oil in a typical cooling system operating in medium or high temperature applications; and (b) whether the resulting mixture provides parameters characterizing behavior, pressure, and temperatures, the same as for a system operating on R12.

The cooling system used included a 0.37 kW hermetic air-cooled compressor of the Danfoss type, model DA05H1AAN with a design evaporation temperature of -6 to + 10 ° C and a power of 967 W to 1861 W / h. This unit was connected to the tube of the tube evaporator, and a visual oil level indicator was attached to the compressor. 3G oil (with a viscosity of 150) was poured into the system, and it worked as a condensing system for condensing R22 vapor from the top of a heated cylinder. Condensate flowed due to gravity from the evaporator / condenser to a second, unheated cylinder. System performance was determined by the mass of R22, condensed over a certain period of time. The steam flow of R22 to the evaporator / condenser was manually limited to provide different loading conditions. All readings of pressure, temperature performance and current were taken every hour and averaged over a period of six to eight hours. The taps on the discharge line and the inlet of the evaporator facilitated the sampling of steam and made it possible to add measured amounts of pentane to the system.

3Gs oil (150 viscosity) was poured into the system. The system worked as a condenser system for condensing R22 vapor from the top of a heated cylinder, and the condensate drained by gravity from the evaporator / condenser into a second, unheated cylinder. System performance was determined by the mass of R22, condensed over a certain period of time. The steam flow of R22 to the evaporator / condenser was manually limited to provide different loading conditions.

In stage 1 of the test, the system first worked with a load of 1.2 kg R12. The following data were observed and recorded: voltage, current, suction pressure, suction temperature, discharge pressure, discharge temperature, liquid line temperature, evaporator temperature, ambient temperature, oil level, source and receiving cylinder temperatures, and process speed in kg / m These data were measured every hour and averaged over a period of 18 hours. During this time, the temperature in the evaporator was controlled by restricting the gas inlet for purging and monitored in the temperature range between -34 ° C and -6 ° C.

In stage 2 of the test, all R12 was removed from the system, while the oil was left in place. Then, R12 was replaced with R134a in an amount of approximately 90% by weight of the initial charge of R12. The oil level was recorded again. Then the cooling system worked for several days, and the above data were recorded at hourly intervals.

It was noted that after many days of operation under different loads, the oil level in the compressor did not change.

Then a 15 m suction line was added to the system, also without changing the oil level. Then the oil return slowed, and after several days of operation, the oil level fell by about 10 mm.

Pentane was added to R134a in a maximum amount of 2% by weight of the initial charge. After approximately 18 hours, the oil level increased by approximately 6 mm.

Later, additional pentane was added to a maximum of 6% of the initial refrigerant charge with a slight increase in the oil level observed with each pentane addition.

Referring to Table 3, the following observations can be made regarding stage 2 of the test (compared with stage 1):

(a) oil recovery improved with the addition of pentane;

(b) the performance was slightly higher under all loading conditions;

(c) energy consumption was slightly lower under all loading conditions;

(d) discharge pressures were on average slightly higher;

(e) the suction pressures were on average the same;

(f) discharge temperatures were on average slightly higher;

(g) the suction temperatures were on average significantly higher and

(h) there was no noticeable adverse effect on the operation of the system or its components.

When testing an open flame and determining the percentage by the peak area of the chromatogram, it was noted that the mixture became flammable at concentrations of 10% or more of pentane.

The fractionation of the mixture was obvious at a percentage ranging from 1% to 20% pentane, or a mixture with 6 wt.%.

It was assumed that pentane could be concentrated in compressor oil during the non-working part of the cycle.

It can be concluded that a mixture of R134a plus 2% pentane as a replacement additive provides oil return and equal or better performance and higher efficiency for medium- and high-temperature commercial R12 systems without a direct negative impact on equipment or operation. From a flammability standpoint, mixtures containing more than 2% pentane could be separated under certain conditions. Systems with large loads of cooling oil and relatively small loads of compressor crankcase oil could be susceptible to compressor damage if the pentane content in the oil reached concentrations that could affect the lubricity of the oil or cause the oil to foam at startup after long periods of shutdown.

EXAMPLE 4

R12 and several R134a / pentane mixtures were tested using an automotive air conditioning system to determine if the mixture that is best suited for commercial refrigeration systems (see the previous example) can also be used as an additive to replace R12 in automotive air conditioning systems air.

The air conditioning system was a 1990 Chrysler mini van with a 3.3 liter engine. The R12 charge existing in the air conditioning system was drained and the system was evacuated to a pressure of 300 microns. Then, 0.82 kg of R12 was poured into it again, as recommended by the car manufacturer. Finally, temperature sensors were installed on the suction line, discharge line, air outlet from the evaporator and in the air-conditioned space of the system.

At the test stage 1, the suction pressure, discharge pressure, suction temperature, discharge temperature, temperature of the air leaving the evaporator, the temperature of the air-conditioned space, the ambient temperature and the engine speed in the system at idle were measured and again at 2000 rpm. All data was recorded when the car was stationary.

In test step 2, the R12 with which the test was conducted was drained and the system was again evacuated to a pressure of 300 μm. Then, a mixture of R134a with 2% pentane was again poured into the system to a volume equal to 90% of the initial recommended load. The same data were recorded as in stage 1 of the test.

Finally, in step 3 of the test, the R134a / pentane mixture was drained and the system was again evacuated to a pressure of 300 μm. Then, R134a (88%) / R125 (10%) / pentane (2%) was poured into the system. The same data was recorded again.

With reference to Table 4, it can be seen that in stage 2 (compared to stage 1):

(a) discharge pressures were on average 8% higher at idle and 4% higher at 2000 rpm;

(b) the discharge temperatures were on average 3% lower at idle and 12% lower at 2000 rpm;

(c) other indications of temperature and pressure did not give significant changes;

(d) there was no noticeable performance loss in the system, and

(e) there was no noticeable adverse effect on the operation or components of the system.

With reference to Table 5, it can be seen that in stage 3:

(a) there was no noticeable change in temperature and pressure when 10% R125 was added to the mixture, and

(b) there was no noticeable adverse effect on the operation or components of the system.

EXAMPLE 5

R12 and several R134a / pentane / R125 mixtures were tested using a 2 liter 1987 Toyota Camry air conditioning system.

As in Example 4, the existing R12 charge was removed from the air conditioning system, and the pressure of this system was reduced to 300 μm. Then, 0.68 kg of R12 was poured into it again, as recommended by the car manufacturer. The air conditioning system was equipped with temperature sensors on the suction line, discharge line, air outlet from the evaporator and in the air-conditioned space.

In stage 1 of the test, data was measured including suction pressure, discharge pressure, suction temperature, discharge temperature, temperature of the air leaving the evaporator, the temperature of the air-conditioned space, the ambient temperature and the engine speed in idle mode and again at 2000 rpm . All data was recorded while the vehicle was stationary.

In step 2 of the test, R12 was drained from the system and evacuated to an air pressure of 300 μm. Then, a mixture of R134a (88%) / R125 (10%) / pentane (2%) was added to the system in an amount of 90% of the initial charge. The same data were recorded as in stage 1.

With reference to Table 6, it can be seen that in stage 2 (compared to stage 1):

(a) the discharge pressures were on average 18% higher under idle conditions and 6% higher at 2000 rpm and

(b) there was no apparent adverse effect on the operation or components of the system.

From Examples 4 and 5, it was concluded that a mixture of R134a plus 2% pentane, introduced instead of R12 in automotive air conditioning systems, appears to provide similar performance and does not have an immediate negative effect on equipment or work. Adding 10% R125 to the above mixture does not have any noticeable effect on previous system pressures and temperatures.

EXAMPLE 6

R12 and several R134a / pentane / R125 formulations were tested using a home refrigerator and freezer systems.

The first test used a home refrigerator system. The technical data of the system was as follows:

Manufacturer: General Electric.

Size: 198 cc liters.

Power: 1 kW.

Type: with one door; one evaporator with a freezer compartment;

without protection against freezing ice.

Age: approximately 25 to 30 years.

Refrigerant charge: 0.128 kg.

Voltage: 115/1/60,

Pressure gauges were installed on the suction and discharge lines. Temperature sensors were connected to the suction and discharge lines approximately 15 cm from the compressor.

At the first stage, the system worked with the existing R12 refrigerant charge. The following data were recorded - voltage, amperage, suction pressure, suction temperature, discharge pressure, discharge temperature, volume temperature, ambient temperature and compressor operating time.

In the second stage, the R12 charge was drained and the system was evacuated to a pressure of 300 μm. Then, a mixture of R134a / pentane (98/2%) was again poured into the system in an amount of approximately 90% by weight of the initial charge. The system was started again, and the same data was recorded as before.

Finally, in step 3, the R134a / pentane mixture was drained, and the mixture R134a / R125 / pentane (88/10/2%) was again poured into the system in the same amount by weight as in step 2. The system was restarted, and recorded the same data as before.

The results of these three stages are shown in Table 6.

The second test used a home freezer. The technical data of the system was as follows:

Manufacturer: Viking.

Size: 482 cube liters.

Power: 2 kW.

Type: chamber type, without protection against ice freezing.

Age: approximately 25 to 30 years.

Refrigerant charge: 0.434 kg.

Voltage: 115/1/60.

Pressure gauges were installed on the suction and discharge lines. Temperature sensors were installed on the suction and discharge lines approximately 15 cm from the compressor.

At the first stage, the system worked with the existing R12 refrigerant charge and recorded the following data: voltage, current, suction pressure, suction temperature, discharge pressure, discharge temperature, temperature in the chamber volume, ambient temperature, and compressor operating time.

In the second stage, the R12 charge was drained and the system was evacuated to a pressure of 300 μm. Then, a mixture of R134a / pentane (98/2%) was again poured into the system in an amount of approximately 90% by weight of the initial charge. The system was started again, and recorded the same data as before.

Finally, in stage 3, the mixture R134a / R125 / pentane was drained and replaced with the mixture R134a / R125 / pentane (88/10/2%) in the same amount by weight as in stage 2. The system was again activated and fixed same data.

Data for all three stages are reproduced in Table 7.

With reference to Table 7, it is seen that when replacing the mixture there are no noticeable differences in operating pressures, temperatures or efficiencies. There was no apparent adverse effect on the operation or components of the system.

In conclusion, a mixture of R134a plus 2% pentane, which was replaced by R12 in home refrigerators and freezers, appears to provide similar performance and does not give immediate negative effects on equipment or work. The addition of 10% R125 to the above mixture does not have any noticeable effect on previous pressures and temperatures or on the operation of the system (see table 8).

EXAMPLE 7

Field tests were carried out on a commercial cooling system using a mixture of K134a / K125 / isopentane / butane in a ratio of 95/5/1/2 wt.%. This refrigerant mixture was loaded into the system and the behavior was compared with previous test data. The results are shown in Table 9. Injection at other pressures and temperatures, productivity and energy efficiency were similar to the values for the mixture R134a / R125 / pentane in a ratio of 88/10/2%. The oil level remained consistent throughout the test. It was noted that replacing pentane with an isopentane / butane mixture provided the same oil return properties and that reducing the R125 content from 10% to 5% was not detrimental to performance.

Claims (12)

1. The composition of the refrigerant, consisting of a fluorocarbon component consisting of 1,1,1,2-tetrafluoroethane (R134a) and pentafluoroethane (R125), in which the mass contents of R125 and R134a are in the ranges: R125 1-17% R134a 83-99% and additives selected from saturated hydrocarbons or mixtures thereof, boiling in the range from -5 to + 70 ° C, and the hydrocarbon additive is selected from n-pentane, isopentane, cyclopentane and mixtures thereof. 2. The composition of the refrigerant according to claim 1, in which the mass content is in the intervals: R125 2-15% R134a 85-98% 3. The composition of the refrigerant according to claim 2, in which the mass contents are in the intervals: R125 9-13% R134a 87-91% 4. The composition of the refrigerant according to any one of claims 1 to 3, in which the hydrocarbon additive is n-pentane. 5. The composition of the refrigerant according to any one of claims 1 to 4, in which the hydrocarbon additive further includes butane. 6. The refrigerant composition of claim 5, wherein the hydrocarbon is a mixture of n-pentane, isopentane and butane. 7. The composition of the refrigerant according to claim 5 or 6, in which the ratio of pentane: butane is from 1: 3 to 1: 8. 8. The composition of the refrigerant according to claim 7, in which the specified ratio is 1: 5.  9. The refrigerant composition according to any one of claims 1 to 8, in which the hydrocarbon additive further comprises a hydrocarbon selected from the group consisting of 2-methylpropane, 2,2-dimethylpropane, hexane, 2-methylpentane, 3-methylpentane, 2, 2-dimethylbutane, methylcyclopentane and mixtures thereof. 10. The composition of the refrigerant according to any one of claims 1 to 9, in which the amount of hydrocarbon additive is from traces to 10%. 11. The composition of the refrigerant according to claim 10, in which the amount of hydrocarbon additives is from 1 to 8%. 12. The composition of the refrigerant according to claim 11, in which the amount of hydrocarbon additives is from 2 to 4%.

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