Energy conversion during static flash of aqueous NaCl solution was newly analyzed with steam-carrying effect taken into consideration. The energy converted into latent heat of flash steam was defined as used energy, and its fraction in total released energy from unit mass of initial waterfilm was defined as energy conversion efficiency (ECE), which varied between 0.023 and 0.991 in current experimental range. Results also suggested that, first, ECE increased with rising initial temperature of waterfilm or with slowing down flash speed, but it decreased with the increasing of superheat, or initial height, or initial concentration of waterfilm. Third, both ECE and the used energy could be improved simultaneously by reducing superheat and at the same time enlarging orifice diameter while keeping other initial parameters unchanged. At last a calculation formula for ECE was proposed within acceptable error range. (C) 2014 Elsevier Ltd. All rights reserved.