Study of the explosion characteristics and combustion products of air conditioner using flammable refrigerants

Due to ozone depletion and high global warming potential of chlorofluorocarbon, environmentally benign options such as hydrocarbons and hydrofluorocarbons (such as R290, R32) are under consideration. Since these refrigerants are flammable, they pose additional fire and explosion risks. The explosion pressures of R32 and R290 at different concentrations were studied using 20 L ball explosive test apparatus. The indoor unit combustion, total heat release, carbon monoxide, and carbon dioxide production were studied in the event of the indoor unit being ignited by an external fire. It is found that the maximum explosion pressures of R32 and R290 are basically the same. Besides, heat and smoke mainly come from the combustion of indoor unit plastic shell and compressor lubricants.