Experimental Study on the Thermal Performance of Novel Salt-Endothermic Reactor

Abstract

Abstract. Endothermic reactors have garnered significance in biotechnology, industrial, environmental, and electronics applications. In the present work, a novel endothermic reactor is proposed, where cooling is achieved through the controlled dissolution of salt mixtures via water dripping. A closed-loop system is designed where water is used as a working fluid to exchange heat between the heat source and heatsink (endothermic reactor). The thermal performance of sodium chloride (NaCl), ammonium chloride (NH4Cl), and their mixtures is explored to examine their capability for heat absorption. The effect of different ratios of salts by weight (Rw = mNaCl/mNH4Cl) at different heating powers and water dripping rates on temperature control is examined. The performance of the salt reactor at different parameters is examined through the rise in plate temperature (ΔTplate). It is found that Rw = 50:50 gave the best cooling (ΔTplate = 3.4 K for 60 min) among all salt mixtures, while NH4Cl (ΔTplate = 3.8 K for 60 min) outperformed NaCl (ΔTplate = 4.5 K for 60 min) for single salt performance. Plate temperature development turned nonlinear after around 10 min as increasing dissolution enabled the dripping water to enter the entire salt bed and trigger dispersed endothermic reactions all around the volume, which led to three-dimensional heat absorption. The lowest dripping rate (Q = 3 ml/min) demonstrated the optimum cooling effect over other faster dripping rates. This work will help in achieving an efficient endothermic reactor, primarily contributing to Sustainable Development Goals by focusing on improving energy efficiency.