4 Kinds of Flammable and Explosive Refrigerants, You Must Know!

Refrigerants are widely used in refrigeration equipment, including household, commercial, and transportation refrigeration and air conditioning systems such as automobiles, refrigerators, air conditioners, dehumidifiers, and water dispensers. We also often hear the news that refrigerants explode due to improper operation, so Fotech has compiled the following common flammable and explosive refrigerants for your reference and study.

R32, also known as difluoromethane and carbon difluoride, is colorless and odorless, and its safety level is A2. R32 is a freon substitute with excellent thermodynamic properties, with a lower boiling point, lower vapor pressure and pressure ratio, larger refrigeration coefficient, zero ozone depletion value, smaller greenhouse effect coefficient, flammable and explosive, etc. The combustion limit in the air is 15%~31%, and it will burn and explode in case of an open fire.

R32 has a lower viscosity coefficient and higher thermal conductivity. Although R32 has many advantages, R32 is a flammable and explosive refrigerant, and the installation and maintenance of air conditioners is a dangerous job. Now coupled with the uncertain factors of R32, safety issues have to be considered. Vacuuming is required for the installation and welding of R32 refrigeration equipment.

R290 (propane) is a new type of environmentally friendly refrigerant, mainly used in central air conditioners, heat pump air conditioners, household air conditioners and other small refrigeration equipment. As a hydrocarbon refrigerant, R290 has an ODP value of 0 and a GWP value of less than 20. Compared with common refrigerants, R290 has obvious environmental protection advantages, as shown below:

1. The damage to the ozone layer by R22 refrigerant is 0.055, and the global warming coefficient is 1700;

2. R404a refrigerant has zero damage to the ozone layer and a global warming coefficient of 4540;

3. R410A refrigerant has zero damage to the ozone layer and a global warming coefficient of 2340;

4. R134a refrigerant has 0 damage to the ozone layer and a global warming coefficient of 1600;

5. The damage to the ozone layer by R290 refrigerant is 0, and the global warming coefficient is 3.

In addition, R290 refrigerant has the characteristics of larger latent heat of evaporation, good fluidity, and energy saving. However, due to its flammable and explosive characteristics, the filling amount is limited, and the safety level is A3. Use R290 refrigerant grade to be evacuated and forbidden to open fire, because the mixture of air (oxygen) can form an explosive mixture, and there is a danger of combustion and explosion in case of heat source and open fire.

R600a refrigerant is a new type of hydrocarbon refrigerant with excellent performance. It is derived from natural ingredients, does not damage the ozone layer, has no greenhouse effect, and is environmentally friendly.

It is characterized by large latent heat of evaporation, strong cooling capacity, good flow performance, low conveying pressure, low power consumption, and slow load temperature recovery. Compatible with various compressor oils. It is a colorless gas at room temperature and a colorless and transparent liquid under its own pressure. R600a is mainly used to replace R12 refrigerant, and now it is mostly used in household refrigerator equipment.

The explosion limit volume of R600a refrigerant is 1.9% to 8.4%, and the safety level is A3. It can form an explosive mixture when mixed with air. When encountering heat sources and open flames, there is a danger of combustion and explosion. The lower part spreads to a considerable distance, and it will catch fire and reignite when it encounters a fire source.

Finally, let's talk about the R717 (ammonia) refrigerant. Ammonia is more dangerous than the above three kinds of refrigerators. It belongs to the toxic medium, and the toxicity is grade 2.

When the volume concentration of ammonia vapor in the air reaches 0.5 to 0.6%, people can be poisoned if they stay in it for half an hour. The nature of ammonia determines that the operation and maintenance of the ammonia system must be standardized, and the refrigeration personnel should pay attention to it. Previously, our Refrigeration Encyclopedia public account has issued a training manual on the use of ammonia refrigerants and precautions, and interested friends can read it.

Ammonia is a medium-temperature refrigerant. Pure ammonia has no adverse effect on lubricating oil, but when there is moisture, it will reduce the lubricating effect of refrigeration oil. Copper and copper alloys are not used for pipes and valves in ammonia refrigeration systems.

The advantages of ammonia as a refrigerant are easy availability, low price, moderate pressure, large unit cooling capacity, high heat release coefficient, almost insoluble in oil, low flow resistance, ease to find when leaking, no damage to the ozone layer, no greenhouse effect. The disadvantage is that it has a pungent odor, is toxic, can burn and explode, and has a corrosive effect on copper and copper alloys.

When the volume of ammonia vapor in the air reaches 0.5-0.6%, it can cause an explosion. Therefore, the concentration of ammonia in the air in the equipment room shall not exceed 0.02 mg/L. Ammonia is a combustible gas at room temperature, the explosion limit is 16% to 25%, the most easily ignited concentration is 17%, and the concentration when the maximum explosion pressure is generated is 22.5%.

The chemical properties of many environmentally friendly refrigerants are flammable and explosive. If the explosion-proof safety of the product is ignored, it will cause a direct explosion of the refrigeration equipment, thus endangering the safety of people and property. If you want to know more about refrigerants after reading the above, please continue to pay attention to our news.

Fotech is a professional manufacturer of refrigerants and fluoropolymers. Our refrigerant gases have outstanding performance in household, industrial and commercial refrigerant systems. Our products have passed various safety certifications, and the quality of the products has also been fully controlled. At the same time, we put the needs of customers first and can provide customers with thoughtful one-stop service. If you are interested in our refrigerants, please contact us immediately!