The Experimental Study on Flow Boiling Heat Transfer of Working Fluid R245fa in Horizontal Tube
- 厦门大学－已发表论文 
设计了管内沸腾换热系数及总传热系数测定试验台架,对R245fa工质在内径6 mm水平光管内的流动沸腾换热特性进行试验研究。测试质流密度为50 ~; 150 kg /(m~2·s),工质蒸发温度为50, 60和70℃。结果表明:; 随着工质含汽率的增加,R245fa的流动沸腾换热系数呈先增大后降低趋势。对于304不锈钢套管式换热器,烟气与R245fa工质进行换热的总传热系数; 约在40 ~ 65 W/(m~2·K) 。A bench - scale facility was designed for testing the flow boiling heat; transfer coefficient and the total heat transfer coefficient. The; boiling heat transfer characteristics of the R245fa refrigerant were; studied in a horizontal smooth tube with 6 mm inner diameter. The; parameters investigated were mass flow rate (50 ~ 150 kg /(m~2·s)),; evaporation temperature (50, 60 and 70 ℃). The results showed that the; flow boiling heat transfer coefficient of R245fa increased with the; increase of rate of vapor content, and decreased slightly with the; further increase of rate of vapor content. The total heat transfer; coefficient of the flue gas and the R245fa is about 40 ~ 65 for the 304; stainless steel heat exchanger.