水蒸気-空気混合気の細い鉛直管外面への自由対流凝縮(熱工学, 内燃機関, 動力など)

抄録

This paper deals with an experimental study of free convection condensation of steam air mixture on a vertical tube. The experiment is made using two copper tubes of 6mm and 4mm in outer diameter. The range of concentration of air is 0.1∿0.9. Condensation rate is measured as well as overall heat transfer rate. The convection heat flux is obtained by subtracting the condensation heat flux from the heat flux at the cooling surface. The equations for predicting condensation mass flux, convective heat flux at the liquid vapor interface, and heat flux at the cooling surface are proposed by modifying corresponding equations for a vertical flat surface. The newly proposed equations correlate the respective experimental results within the error of several percents irrespectively of the wettability of the tube surface.