화학공학소재연구정보센터
International Journal of Energy Research, Vol.44, No.7, 6035-6048, 2020
Experimental research on titanium dioxide nanofluid in vacuum flash evaporation
This study is purposed to conduct experimental investigation into the characteristics of vacuum flash evaporation with nanofluid under adsorption conditions, with the effects of nanoparticle concentration, surfactant concentration, and nanofluid stability taken into consideration. By measuring absorbency, solute concentration, and sedimentation graph, a new nanofluid with excellent dispersion was developed for the vacuum ice-making system. It has been demonstrated that the low concentration of additive is conductive to not only the maintenance of vacuum but also the generation of binary ice. For nanofluid, there are two distinct freezing stages in the process of vacuum flash evaporation. The supercooling stage of nanofluid is delayed with the increase of surfactant concentration, whereas the TiO2 nanofluid applied to the vacuum ice-making system under adsorption shows stability. Moreover, it is indicated that, for the vacuum ice-making system with TiO2 nanofluid, the pH level is around 8.5, the surfactant is sodium dodecyl benzene sulfonate-span 60 (SDBS-SPAN), the ratio of SDBS to SPAN is about 10:7, the concentration of TiO2 nanoparticle is around 0.20 wt%, and the ratio of TiO2 nanoparticle to SDBS-SPAN is about 10:5. Compared with pure water, undercooling is reduced by 77.92%; the ice packing factor and thermal conductivity are increased by 40.61% and 67.27%, respectively. The results of test and analysis can be applied to conduct further research on vacuum flash evaporation.