Factors Affecting Ice Fraction during Freezing of Aqua Glycol Salt Solution

Abstract

In this study, the primary objective of formulating aqua–glycol–salt solutions (AGSS) is to develop an effective thermal energy storage material (TESM). The ice fraction plays an important role in TESM as it directly reflects the amount of latent cooling energy stored within the material. The ice fraction in AGSS at different PG and NaCl concentration was determined as a function of freezing time and statistically analyzed using a two-way ANOVA. The maximum concentration (9.6 °Bx) of AGSSs after freezing of 180 min was observed in 6% PG with 5% NaCl and minimum concentration (0.6°Bx) in 2% PG with 0% NaCl AGSS. The maximum ice fraction (0.79) of AGSS was observed in the formulation containing 2% Propylene   glycol (PG) with 0% NaCl. While the minimum ice fraction (0.25) was obtained in the 6% PG with 5% NaCl formulation after 180 minutes of freezing. The results highlight the influence of component concentration and freezing time on ice formation. As the concentration of PG and NaCl in AGSS is increased, ice fraction decreased significantly because of the freezing point depression. This study provides valuable insights for deciding the concentrations of PG and NaCl to achieve desired thermal performance of TESM in various cooling applications such as industrial refrigeration system, food preservation and thermal energy storage systems.