1. Characteristics of commonly used refrigerants

1. R717 (ammonia)

Ammonia: ammonia is currently the most widely used medium pressure medium temperature refrigerant.Ammonia standard of solidification temperature is 77.7 ℃, the evaporating temperature of 33.3 ℃, the condensing pressure generally at room temperature is 1.1 ~ 1.3 MPa, even when the summer cooling water temperature as high as 30 ℃ less than 1.5 MPa.It is mainly used in large industrial refrigeration and commercial refrigeration.

Solubility is easy to obtain, low price, moderate pressure, large unit cooling, high exothermic coefficient, almost insoluble in oil, low flow resistance and easy to find when leaking.But it has irritating odor, toxic, can burn and explode, and has corrosive effects on copper and copper alloys.

2, R22

Refrigerant R22: R22 is a kind of medium temperature, its standard boiling point of 40.8 ° C, water solubility in the R22 is very small, and mineral oil dissolve each other, R22 does not burn, nor the explosion, toxicity is small, R22 searches ability is very strong, and leaks are difficult to find.

The invention is widely used in air conditioners, heat pumps, dehumidifiers, refrigerating dryers, cold storage, food refrigeration equipment, Marine refrigeration equipment, industrial refrigeration, commercial refrigeration, refrigeration units, display and display cabinets in supermarkets, etc.

3, everything

As an alternative refrigerant to R12, R134a has very low toxicity and is not flammable in the air.Widely used in: refrigerators, freezers, water dispensers, automobile air conditioners, central air conditioners, dehumidifiers, cold storage, commercial refrigeration, ice water machines, ice cream machines, freezing condensers and other refrigeration equipment

Everything chemical stability is good, but because of its higher water soluble, so adverse to the refrigeration system, even if there is a small amount of water, under the action of lubricating oil and so on, will produce a acid, carbon monoxide, carbon dioxide or to metal corrosion effect, or "copper" effect, so everything on the system of the dry and clean even more demanding.

4, R404A

Solur404a is a colorless gas at room temperature and a colorless transparent liquid under its own pressure. It is a non-azeotropic refrigerant without chlorine.Suitable for new commercial refrigeration equipment, transportation refrigeration equipment and refrigeration equipment at medium and low temperatures.

Stalr404a is mainly used to replace R22 and R502. It has the features of cleaning, low toxicity, non-combustion and good refrigeration effect, and is widely used in medium and low temperature refrigeration systems.Its ODP is 0, so R404A is a refrigerant that does not destroy the ozone layer in the atmosphere.

5, R410A

Stalr410a is mainly used to replace R22 and R502. It has the characteristics of cleaning, low toxicity, non-combustion and good refrigeration effect, and is widely used in household air conditioners, small commercial air conditioners and household central air conditioners.

The operating pressure is 1.6 times higher than the average R22 air conditioner, and the efficiency of refrigeration (heating) is high.R410A refrigerant consists of two quasi-azeotropic mixtures, R32 and R125, each containing 50%, mainly hydrogen, fluorine and carbon.R410A is currently recognized internationally as the most suitable refrigerant to replace R22, and has been popularized in Europe, America, Japan and other countries.

6, R407C

The solute R407C is a chlorine-free fluorothane non-azeotropic mixed refrigerant, colorless gas, which is compressed liquefied gas stored in a cylinder.The ODP is 0, and R407C is a long-term substitute for R22 due to its extremely similar characteristics and performance with R22. It is used in air-conditioning system and non-centrifugal refrigeration system.

R407C is mainly used to replace R22. It has the characteristics of clean, low-toxicity, non-combustible and good refrigeration effect. Under the condition of air conditioning, its unit volume refrigerating capacity and refrigeration coefficient are 5% lower than that of R22.At low temperatures, its cooling coefficient does not change much, but its cooling capacity per unit volume is 20% lower.

7, R600a

Stalr600a is a new type of hydrocarbon refrigerant with excellent performance. It is derived from natural components, does not damage the ozone layer, has no greenhouse effect, and is green and environment-friendly.It is characterized by high latent heat of evaporation and strong cooling capacity.Good flow performance, low transmission pressure, low power consumption, slow recovery of load temperature.Compatible with various compressor lubricants, it is a substitute for R12.

R600a is a flammable gas. It can be mixed with air to form an explosive mixture.A violent reaction to contact with an oxidant.The steam is heavier than air and can spread quite far at a lower point. In case of fire, the source will catch fire and reignite.

8 R32.

Many refrigerants are interested in R32. Accidents involving this refrigerant are common.A lot of times, refrigerants have a safety accident, not something else, because of a lack of understanding of R32 refrigerants.We hereby emphasize that if it is necessary to replace parts for refrigeration system maintenance, it must be vacuumed before operation.Be careful not to introduce fire!

The solubility R32 is mainly a replacement for R22, a gas at room temperature, a colorless transparent liquid at its own pressure, soluble in oil, insoluble in water, and R32 has a combustion limit of 14%~31% in the air.Although it has zero ozone depletion potential, it has high global warming potential, which is 550 times higher than carbon dioxide every 100 years.

The global warming coefficient of the periodic R32 refrigerant is 1/3 of R410A, which is more environmentally friendly than traditional R410A and R22 refrigerant, but R32 has certain flammability.Relatively environmentally friendly flammability.Compared with R410A refrigerant, R32 high saturation pressure by about 3%, 8-15 ℃ high exhaust temperature, high power, about 3-5%, can effect comparing high about 5%;High efficiency, high operating pressure.At the same operating condition and the same operating frequency as the compressor, the cooling capacity of R32 system is about 5% higher than that of R410A refrigerant.

9 R290.

Stalr 290 (propane), also called cold coal, is a new environment-friendly refrigerant.Mainly used for central air conditioning, heat pump air conditioning, household air conditioning and other small refrigeration equipment.High purity R290 is used as temperature sensing material.The superior and first class R290 can be used as refrigerant to replace R22 and R502, compatible with the original system and lubricating oil, for central air conditioning, heat pump air conditioning, household air conditioning and other small refrigeration equipment.

The solubility test showed that R290 perfusion was about 43% of R22 in the same system volume.Since the latent heat of vaporization of R290 is about twice that of R22, the refrigerant circulation of the refrigeration system using R290 is much smaller.Using R290 refrigerant, the energy saving rate can reach 10-35%.

The deadly flaw in the playful R290 "flammable explosive" is deadly.The R290 can be mixed with air to form an explosive mixture, which is in danger of combustion and explosion in the presence of heat source and open fire.

2. Properties of ideal refrigerant

1. High evaporation pressure

The evaporation pressure is higher: if the evaporation pressure of the refrigerant is lower than the atmospheric pressure, the air is easy to penetrate into the system and the system is difficult to deal with. Therefore, it is hoped that the evaporation pressure of the refrigerant at low temperature can be higher than the atmospheric pressure.

2. The latent heat of evaporation should be large

The latent heat of vaporization is greater: the latent heat of vaporization of the refrigerant is greater, indicating that a large amount of heat can be absorbed by using less coolant.

3. The critical temperature should be high

If the critical temperature is high, indicating that the refrigerant coagulation temperature is high, the refrigerant can be cooled by using ambient air or water to achieve the effect of condensation liquefaction.

4. The condensation pressure should be low

The coolant pressure is low: the cooling pressure is low, indicating that the refrigerant can be liquefied with low pressure, and the compression ratio of the compressor is small, which can save the horsepower of the compressor.

5. The solidification temperature should be low

The freezing temperature is low: the freezing point of the coolant is low, otherwise the coolant freezes in the evaporator and cannot be circulated.

6. The ratio of gas refrigerant to volume is smaller

The specific volume of the gas coolant is smaller: the smaller the specific volume of the gas coolant, the better, the smaller the volume of the compressor can reduce the cost, and the suction pipe and exhaust pipe can use smaller coolant distribution pipe.

7. The density of liquid refrigerant is higher

The higher the density of the liquid coolant, the higher the density of the liquid coolant, the smaller the pipe can be.

8. Soluble in frozen oil

Fluid soluble in frozen oil: soluble in frozen oil, the system does not require an oil separator.

9. Stable chemical properties

Chemical stability: evaporation temperature will vary with temperature changes, such as evaporation temperature of ice water machine is 0 ~ 5 ℃, cold in the refrigeration cycle system, cold media only physical change, without chemical change, not decomposition.

10. Non-corrosive

The latent heat of evaporation is large: non-corrosive to steel and metal, and ammonia corrosive to copper.Good insulation, otherwise it will destroy the compressor motor insulation, so ammonia should not be used in closed compressor, so as to avoid direct contact with copper coil.

11. Non-toxic, non-combustible and non-explosive

12. Do not damage the environment