Transient Pool Boiling Under Self Pressurized Systems

An experimental investigation of the transient pool boiling under self-pressurized systems is presented in this work. A vertical cylindrical heating surface of known surface roughness is used. Test runs are carried out on a closed vessel to attain self-pressurized system while water is utilized as the working fluid. Two glass windows are opened in the test vessel to observe the phenomenon. The increasing pressure and the consequent variable difference between the mean heating surface temperature and the saturation temperature corresponding to the system pressure are measured during each of the test runs. The runs cover an input heat flux from (40 × 10³ to 80 × 10³ W/m²) over a pressure range from the atmospheric to 5.5 bars. For transient conditions, an empirical correlation to relate the heat transfer coefficient to both heat flux and pressure is obtained. Also, a comparative study is performed between the present work and a previous work under steady state atmospheric conditions.