Experimental study on thermal characteristics of pure water flashing evaporation from thin-liquid film

An experimental investigation on thermodynamic phenomena of liquid film flash evaporation is presented. During experiments the pure waterfilm is flashed at an initial temperature range of 60-85 degrees C, an initial liquid film height range of 3-20 mm, and a superheat range of 2-22 K. The results show that the enthalpy difference is the dominant parameter for flashing phenomena and process. The static pressure distribution in the liquid film has an obvious impact on flashing evaporation process since the water static pressure can cause the change of saturation temperature. The liquid film height during the flash can be reached many times of the initial height and it represents the intensity of the flashing. The flashing evaporation can be stepped more rapidly to the mild evaporation due to the lower water film. The NEF(non-equilibrium fraction) and the intensity of the flashing increased with the height of water film.