Experimental study of leakage safety of a novel integral-type air conditioner using R290

Abstract

Ventilation is an efficient method to improve the leakage safety of R290. In this paper, a novel integral-type fresh air air conditioner is proposed. Compared with conventional air conditioner, it improves leaking safety and indoor air quality. Moreover, it has a potential to recover heat from exhaust air. A green house was built to simulate a full-scale living room, and the influences of operation mode, diameter of leakage hole, supply air wind speed on leakage safety were experimentally researched. Results show that the diameter of leakage hole has an overwhelming influence on the concentration distribution of R290. The closer to leakage point, the higher the concentration of measuring points. Under fan mode condition, leakage hole diameter within 1 mm is basically incapable to cause the risk of flame and explosion in indoor space. Under heating mode condition, indoor area is generally safe except for part of supply air outlet right below the leakage point. Moreover, the novel air conditioner has a ventilation flow rate of 30m³/h, which plays a remarkable role in promoting the leakage safety of flesh air air conditioner by decreasing the leaked refrigerant concentration at a rate up to 23%LFL/h. This paper provides reference for developing fresh air air conditioner with flammable refrigerants and the design of optimum wind speed of supply air.