Film Condensation on a Vertical Tube at Different Pressures
The work presented is a numerical and experimental study film condensation of steam on a vertical tube surface at different pressures, power supplied to the evaporation tank and cooling water temperature. The designed system consists of three parts; cold water, steam supply sub-system and the test rig which consists of vertical copper tube. The calculated parameters were measured by local and average condensation heat transfer rate, local condensation heat transfer coefficient, average condensation heat transfer coefficient, tube surface temperature distribution, film thickness and steam condensation rate. It was observed that there is a gradual increase in condensation rate with increasing steam pressure in the test vessel. It was concluded that when we increase the steam pressure this will lead to an increase of the average heat flux, while local heat transfer coefficient is affected by the condensate layer thickness over tube surface. Temperature of the surface tube decrease's continuously in the length of condenser tube and the average temperature of tube is proportional with its steam pressure as maximum average temperature is reached when this P=0.45 bar. The agreement between the experimental and numerical value of the average heat transfer coefficient appears to be reliable with a deviation of about (2-7%).