Experimental investigation of the heat transfer from the helical coil heat exchanger using bubble injection for cold thermal energy storage system

This study investigates cold thermal energy storage (CTES) using a helical coil heat exchanger modified with bubble injection. One of the effective methods for increasing transfer rate in exchangers is A immersed inside cylindrical water tank, where evaporator vapor compression refrigeration cycle (VCRC) and provides designed cooling. Experimental studies were carried out to examine impact injection on Nusselt number, temperature differences exergy degradation evaporator, coefficient performance (COP). The bubbles injected from bottom tank four different geometries at airflow rates ranging 3 11 L/min. experimental results this revealed that could significantly increase COP as well destruction number (Nu). was highly dependent geometry flow also indicated has an optimal value, which 9 L/min study. More specifically, Nu increased by 124% 452%, respectively, compared non-bubble mode. Finally, calculating outside coil, empirical correlation function angle proposed.