De-Stratification and Heat Loss Comparison of Three Thermal Oils in a Small Storage Tank
Abstract
An experimental comparison of de-stratification and heat loss characteristics of three different thermal oils in a storage tank is presented in this paper. The three thermal oils evaluated are Sunflower Oil, Shell Thermia C and Shell Thermia B. A small insulated 20 liter storage tank is firstly charged up with the use of an electrical heater in thermal contact with an oil circulating copper spiral coil. After charging, the storage tank is left to cool down for 24 hr cycles. Cool-down experimental thermal cycles are carried out with the three different oils. De-stratification and heat loss parameters are evaluated. The stratification number is evaluated and it signifies the degree of thermal stratification. Stratification numbers are seen to be slightly higher for Sunflower Oil as compared to the other oils at the later stages of cool-down. The heat loss factor for Sunflower Oil is lower when compared to the other thermal oils, suggesting that it is the superior oil in terms of heat retention.
Keywords
De-stratification, Heat loss, Thermal oils, Storage tank