Energy conversion characteristics of high-concentration aqueous NaCl solution at different flash speeds

In order to achieve the goal of suppressing the steam-carrying effect and improving energy conversion efficiency by adjusting the flash speed, this paper conducted an experimental investigation into the static flash evaporation of high-concentration aqueous NaCl solutions at different flash speeds. The initial concentrations of the waterfilm ranged from 0.15 to 0.26. High-speed camera captured the flash evaporation process at different speeds and the formation of crystals at flash speeds ranging from 0.056 s- 1 to 0.099 s- 1. The results showed that the presence of crystals correlated with a decrease in the non-equilibrium fraction as flash speed increased. In the absence of crystals, the non-equilibrium fraction exhibited a minimum value at increased flash speeds. The steam-carrying ratio decreases as the flash speed drops, and within the experimental range of this paper, the maximum reduction amplitude can reach 99.9 %. Energy conversion analysis indicates that reducing the flash speed consistently improves the energy conversion efficiency of flash evaporation, irrespective of whether crystallization occurs, and the maximum increase amplitude can reach 124 %.