Research on the feasibility and mechanism of the intermittent flash evaporation

Abstract

An intermittent flash evaporation method is proposed. The experimental system of the flashing is realized by an intake or extraction system composed of two solenoid valves and a controller. The feasibility of this flashing method is verified through experiments under conditions of different time ratios of intake to extraction. The mechanism of the intermittent flashing method was studied by analyses of liquid temperature, pressure gradient in the flash chamber, and pressure difference between the flash chamber and the vacuum chamber in flashing processes under different conditions. Results suggested that the amount of steam produced by the flash evaporation with the increase in liquid superheat was more than that of the process with a certain superheat. Periods of intake and the extraction of the intermittent flash evaporation influenced the flashing efficiency significantly. By comparing the results with continuous static flashing, the intermittent flash evaporation is proven capable of improving the flashing efficiency. Appropriate intake and extraction periods promote the flashing process and reduce the amount of air intake in a single flashing cycle.