STUDY OF FLOW BOILING HEAT TRANSFER OF R32 IN SMOOTH HORIZONTAL TUBES WITH VARIOUS INNER DIAMETERS
(0) R32 with low ODP and the GWP of 675 is a promised refrigerant to replace R22 and R410A.Due to the flammability of R32,the charging amount of the R32 is limited.Mini-channel technology is very important way for the design of the heat exchanger to decrease the amount of the refrigerant.In this paper the flow boiling heat transfer characteristics of R32 was measured in smooth horizontal tubes with small diameters.The inner diameter of the test section is from 1mm to 4 mm.The evaporation temperature is 15℃.The mass fluxes range from 100 kg/m2s to 400 kg/m2s.The heat fluxes are from 6 kW/m2 to 24 kW/m2.The results of R32 is about 4-16 kW/m2K under the test conditions.The heat transfer coefficient of R32 in an ID 1 mm tube is almost same as that in an ID 2 mm tube and 4 mm tube and even higher than the latter ones at some conditions.A correlation is proposed to predict the heat transfer coefficient of R32 in various inner diameter tubes.This correlation can agree 80% up data within the deviation of ±30%.
Minxia LI Chaobin Dang Eiji Hihara
Key Laboratory of Efficient Utilization of Low and MediumGrade Energy,MOE,Tianjin University,Tianjin The University of Tokyo,5-1-5 Kashiwanoha,Kashiwa-shi,277-8563,Japan
国际会议
西安
英文
1-8
2012-08-26（万方平台首次上网日期，不代表论文的发表时间）