Research On Heat Transfer Of Vapor Mixed With Non-Condensable Gas In Vertical Tubles

Preceded from the consideration of theoretical request and engineering application,convection-condensation heat transfer of vapor mixed with incoagulable gas in verticaltubes was studied theoretically and experimentally in this paper. Vapor mass fraction inthe gas was about 10%～30%.Firstly, heat transfer characteristics of gas mixture in vertical tubes were introducedand heat and mass transfer of mixture gas were analyzed theoretically. Considered thecharacteristics of liquid film and gas film respectively, their mathematical descriptionsand solution to these equations were established through modified film model andNusselt theory.Secondly, heat transfer of vapor mixed with nitrogen in vertical tubes wasinvestigated under the different situations. Through processing experimental data,convective heat transfer correlations were presented as Nusselt number versus Reynoldsnumber, ranging from 2500-12000. Factors influenting the heat transfer were discussedthrough the theory and engineering application.On this basis, the mathematical descriptions of nitrogen-reclaiming coolingcondenser was buit."DHS cooling condenser" software was designed. Heat transfercharacteristics of nitrogen-reclaiming cooling condenser was analysed by the software.Effective measures of enhanced heat transfer were suggested.At last, a new type of cooling condenser used in nitrogen reclaiming was proposed.