Experimental investigation of additives enhanced vacuum flash evaporation for binary ice generation

In this study, an experimental investigation was conducted into the characteristics of different varieties of additives (including CaCl 2 , ethanol, and TiO 2 nanoparticles) in the vacuum ice-making system under adsorption condition. The concentration of CaCl 2 , ethanol, and TiO 2 nanoparticles were treated as experimental variables, while the supercooling degree, ice packing factor (IPF), flashing rate, thermal conductivity, and latent heat were taken as evaluation parameters. According to the experimental results, 0.20 wt% TiO 2 nanoparticles and 1 wt% CaCl 2 are applicable as additive, the former is superior to the latter, and ethanol is not suitable for use as additive. Under the optimal conditions, compared with distilled water, the supercooling degree, IPF, and thermal conductivity of TiO 2 nanofluids are improved by 77.92%, 40.61%, and 57.23%, respectively; for CaCl 2 solution, the supercooling degree and IPF are improved by 9.96% and 84.67%, respectively. Furthermore, though the flashing rate increases with the addition of additives, the flashing driving force remains sufficient. The latent heat of nanofluids is barely affected by the addition of nanoparticles. As the CaCl 2 concentration is on the rise, both the thermal conductivity and the latent heat of CaCl 2 solution show a decreasing trend.