Analysis of Indoor Environment Safety with R32 Leaking from a Running Air Conditioner

Abstract

This paper, in the view of indoor security, analyzes the leak variation and indoor R32 concentration distribution when it leaks from the running indoor unit using experimental methods. The results show that the leak rate of R32 decreases with the air conditioner operating. And the leak process of refrigerant under operating conditions can be classified into two stages, fast leak stage and slow leak stage. The concentration of test points increases at first, then decreases and gradually stabilizes. Near the leak hole, it is the highest and varies dramatically. And it is high in the supply air mine stream, but it is only about 15% of the LFL. The concentration of the corner that the supply air cannot reached is the lowest. The indoor security during the leaking process of R32 is evaluated, and the results show that the combustible zone only appears near the leak hole, and its duration is very short. Ignition experiment is took in the combustible region and the results show that the candle flame and spark diffuse slightly, but it cannot spread effectively. It can be concluded that the hazard of using R32 as the refrigerant of air conditioner is low with the air velocity and angle keeping at 5.8m/s and 25°. In order to improve the security of the indoor environment further, the paper also analysis the impact of exhaust on indoor R32 concentration distribution and the results indicate that ventilation can reduce the indoor R32concentrationeffectively. Thus, it can reduce the risk of fire by opening the exhaust fan when R32 leaks with the air conditioner running.