In this study

an experiment was conducted to compare and analyze the concentration diffusion law of R32 gas in different planes ofthe testedroom following leakage from different positions of 3.6 kg R32 refrigerant. The safety impact in the room when the lower flammable limit (LFL) was reached for the first time in typical planes was analyzed along with the flammable risk time. The results showed that when the height of the leak position increased

the concentration diffusion rate of refrigerant gradually converged along the height direction. The concentration increase and decrease rates remained at approximately 0.5%/min and 0.06%/min

respectively. When the refrigerant gas leaked horizontally from the upper part of the room

the maximum concentration and concentration diffusion rate at the plane near the leak was reduced by approximately 50%

with the flammable risk time reduced by approximately 78%. The flammable risk time at the lower part of the room increased gradually with the height of the leak location. When the leak was in the upper part of the room

the LFL value was reached first at the bottom of the room and then in the planesthat are close to the leaking position.