NUCLEATE POOL

Abstract

This thesis presents an experimental investigation on pool boiling of water and ethyl acetate at atmospheric and subatmospheric pressures. The test section was a horizontal stainless steel tube 25.5 mm 0.D. and 173 mm long. The tube was internally heated by means of an electric heater ?made of nichrome wire wound on a porcelain rod. Calibrated copper constantan thermocouples were used for measuring wall and liquid temperatures. The energy input to the test section was measured by a wattmeter. The liquid temperature was varied to cover the regions of natural convection through subcooled to saturated boiling. The heatflux ranged from 12..44x103 to 43.54x103 Kcal/hr,m2. The pressures used were 725, 625 and 470 mm of Hg. The experimental data for distilled water during both natural convection and saturated boiling at 1 atmosphere pressure were found to compare well with the results of earlier workers. The values of heat transfer coefficient for both the systems.,Water and ethyl acetate, were found to increase with the increase in pressure during boiling. The increase in degree of subcooling was found to decrease the value of heat transfer coeffi-cient. The value of heat transfer coefficient increases with the increase in heat flux.