AN ANALYSIS AND ASSESSMENT ON THE EXPLOSIVE HAZARDS OF LEAKAGE FLAMMABLE REFRIGERANTS

When trying to find the alternatives for CFC and HCFC as refrigerants, we know that the most environment protection friendly refrigerants are HC series, such as R290, R600, R600a, HFCs, R32, R143a, R152a, etc. However, HCs and the most of HFCs are flammable. Thus, it has become a serious problem to develop ways to use such substances safely. To achieve this purpose, the present authors have done detailed analyses and evaluations on how to eliminate the explosive hazards of flammable refrigerant leakage in the air conditioned room. So far they have established a model in calculating the average flammable refrigerant concentration in the air conditioning room after finding the leakage. The results of computation show that the concentration is only half of the explosive limits when 600 g HCs or 1 200 g HFCs are used as refrigerant for a limited air conditioning room leakage. The liability of explosion triggered by such amount of leakage can be confined in a limited space near the leakage point. Analyzing damage range and the damage level of the explosion by using the P I method, the authors conclude that the damage can be tiny, but the fire it may cause is likely to be the main danger for the damage. Their conclusions of the two methods prove to be almost the same. Therefore, with the proper measures taken, such flammable refrigerants as HCs and HFCs remain to be applicable in the restricted air conditioning spaces.