Analysis of Thermal Characteristics of Flash Evaporation of Static Liquid Film

This paper presents a complete heat and mass description of a static liquid film of water under low flashing conditions through an experimental analysis. The experiments are performed with initial water film heights of 100 and 120 mm, superheat degree ranging from 2 to 38 °C, and temperature of water film from 65 to 80 °C. To examine the impact of superheat, beginning temperature, and depressurization on the flashing phenomenon, the parametric investigation is also carried out. Finally, it is suggested that lower water film heights exhibit less effect of gravity and cause lesser change of saturation temperature. Findings indicated that a lesser value of the equilibrium temperature is reached, and a large quick temperature decrease occurred at lesser initial back pressure and larger water initial temperature. A digital camera is positioned in front of the vaporization chamber to capture and record images of the flash phenomenon. It is noted from the experiments that by decreasing the back pressure value from 31.32 to 11.32 kPa, the temperature drop is enhanced by 32.3%. Results also recommended that increasing the water film height by 20 mm reduces the film’s temperature by 0.5 °C.