Performance comparison between R290 and R22

Refrigerant R290, namely propane, is a natural hydrocarbon refrigerant which can be obtained directly from liquefied gas.  Compared with freon, a synthetic refrigerant, the molecule of natural working medium R290 does not contain chlorine atoms, so the ODP value is zero, and it has no damage to the ozone layer.  In addition, the GWP value of R290 is close to 0 compared with that of HFC, which also has no effect on the greenhouse effect.  Currently in Germany R290 has been used in household water heaters and air conditioning systems.  

At present, the refrigerant used more in China's air conditioning industry is R22.  R290 and R22 are very close to the standard boiling point, freezing point, critical point and other basic physical properties, and have the basic conditions to replace R22.  In saturated liquid state, the density of R290 is smaller than that of R22, so the perfusion volume of R290 under the same volume is smaller. The test shows that the perfusion volume of R290 under the same system volume is about 43% of that of R22.  In addition, because the latent heat of vaporization of R290 is about twice that of R22, the refrigerant circulation volume of the refrigeration system using R290 is smaller.  R290 has good material compatibility with copper, steel, cast iron, lubricating oil and so on.  

However, R290 can not be applied on a large scale, because its inflammability and explosivity have not been effectively solved, which is the biggest obstacle to its popularity.  To reduce safety risks, the IEC standard sets a limit for the maximum amount of R290 refrigerant that can be safely injected: for a room of 10 square meters with a height of 2.2 meters, the amount of R290 refrigerant must be less than 290g.  After reducing the amount of perfusion, the leakage of refrigerant can be reduced to a certain extent, so as to improve the safety of R290.  Does the decrease of refrigerant perfusion lead to the decrease of cooling capacity?  In response, industry sources.