Experimental investigation of condensation of hydrocarbons inside a mild steel tube.

Heat transfer and pressure drop are investigated in propane condensing inside a tube to generate data for LNG plants. Additionally, those investigations are carried out for single phase superheated gas and subcooled liquid. A new test facility is designed and commissioned. Large variation of pressure, fluids, mass flux, tube size etc. is possible. The first tube examined is a mild steel tube with approximately 21 mm diameter. The tube is horizontally oriented. The temperature is measured locally. The saturation pressure
and the mass flux are varied. The single phase pressure drop results cannot be described with known correlations for smooth tubes so that the equivalent sand roughness for drawn mild steel tubes has to be considered. The single phase heat transfer results are in good agreement to the correlation of Gnielinski. The Nu-Number augments strongly with the Re- and Pr-Number. The heat transfer coefficient for condensation are dependent on vapour quality, pressure and mass flux. The heat transfer in condensation decreases with rising saturation pressure and increases with the vapour quality. The results are compared with the correlation from the literature. The experimental data differ to the model of Cavallini over 30% and to Thome maximum 15% depending on the measurement conditions.