Row Effect for R245fa Condensed on Smooth Tubes and Its Elimination in Shell and Tube Condenser
Row effect (Decrease of condensation heat transfer coefficient (CHTC) on lower tube rows induced by falling condensate from upper tube rows.) is an important factor both in the design and the operation process of shell and tube condenser.So nearly every investigator pursued it in their study of condensation heat transfer on tube bundle.This paper experimentally studied the row effect of bundles (2-row-wide and 5-row-deep) consist of smooth tubes (do=19.01mm),put forward a scheme to eliminate row effect and validated it both by experimental and theoretical investigation.R245 fa,a new substitute of R11,was condensed in the experiment.Diversion duct is equipped on the lower part of each tube of the bundle (except tubes in the undermost row) to avoid row effect.The results show that: (1) Row effect of smooth tube makes good agreement with that predicted by Kems model,but 30 percent less than that predicted by Nusselts model.(2)The equipped diversion duct can eliminate row effect and significantly improve the CHTC of tube bundle consist of smooth tube.(3) For a heat exchanger with a shell diameter of 600mm,20.5 percent heat pipes would be saved by equip the diversion duct on each tube.
Row effect Condensation heat transfer Shell and tube condenser Horizontal tube bundle
Zhixian Ma Jili Zhang Jun Xiong
School of Municipal and Environment Engineering,Harbin Institute of Technology,Harbin,China School of Civil and Hydraulic Engineering,Dalian University of Technology,Dalian,China Department of Architectural Engineering,University of Nebraska at Lincoln,Omaha,NE,USA
国际会议
The First International Conference on Building Energy and Environment(第一届建筑能源与环境国际会议)
大连
英文
1493-1500
2008-07-01（万方平台首次上网日期，不代表论文的发表时间）