ABSTRACT
In this study condensation heat transfer on a cold inclined circular cylinder under natural convection for various conditions is investigated experimentally.
The cylinder is placed in an isolated test room in order to permit pure natural circulation of ambient air. Ambient temperature and humidity of the test room are controlled by refrigeration cycle and humidifying system which is designed and built in the laboratories of Mechanical Engineering Department, Shiraz University. The ambient air relative humidity changed in the range of 30 to 50 percent and temperature of 25 to 35°C. The ethylene-glycol/water solution is used as a refrigerant to control and keep temperature of the test section at a constant value. The cold surface temperature is varied in the range of 2 to 6°C.
The condensation rate is measured with a 5 mega-pixel digital Cannon, Power Shot S3IS camera, with estimated uncertainty of ± 0.07 mm. Images of graded vessel were acquired every 15 minutes and condensation rates is determined by image processing technique.
The condensation rate and heat flux are found to depend mainly on time, temperature difference between ambient air and the cold surface, ambient relative humidity and tube inclination. Results are plotted for various conditions with respect to time.
