Ratio of Heat and Mass Transfer in Airside of Split Fin-and-tube Heat Exchanger under Wet Conditions

MA Xiaokui  DING Guoliang  ZHANG Yuanming

(School of Mechanical Engineering, Shanghai Jiaotong University, Shanghai 200030)

Abstract: The ratio of heat and mass transfer characteristics of split fin-and-tube heat exchangers are studied under wet condition experimentally. Experiments on 7 heat exchangers under 23 working conditions are done. The test results indicate that the ratio of hs/(hmcp,a) increase with increase of fin pitch, the ratio of hs/(hmcp,a) increases with increase of inlet relative humidity at 12 ℃ inlet water temperature, and inlet relative humidity hasn’t significant effect on the ratio of hs/(hmcp,a) at 6 ℃ inlet water temperature. Its range is 0.5~3.7, the Lewis correlation is not suitable for spit fin-and-tube heat exchangers. The experimental data are used to develop the correlations for the ratio of hs/(hmcp,a) with the multiple linear regression technique. The proposed hs/(hmcp,a) correlation has a mean deviation of 7.1% from experimental data and can predict 87.3% of the experimental data within the deviation limit of ±15%. New parameter named as mass-transfer fin efficiency is put forward in order to get the airside mass transfer coefficient during the process of data reduction.

Key words: Split fin  Wet condition  Correlation   Ratio of heat and mass transfer

CLC No: TK124

教育部新世纪优秀人才计划资助项目([2005]290). Received 20070312, received in revised form 20071021