Numerical Analysis of a Latent Heat Storage Using Plate Heat Exchanger for Absorption System Conditions

Abstract

The use of the phase change material (PCM) as a storage medium represents an important advance to store energy for the absorption cooling systems when solar energy is not available; however, the temperature of the storage tank is a key parameter for the adequate operation of the cooling system. This paper presents a parametric analysis of a flat and a commercial plate heat exchangers with MgCl2·6H2O as the PCM at absorption cooling conditions. The plate heat exchanger (PHE) is a chevron type with an angle of 45° and a plate area of 0.04 m2. The governing equation was solved using the method of finite difference. The results showed that the corrugated plate improved the heat transfer than the flat plate; however, the flat plate obtained a higher operation time than the corrugated plate for the absorption cooling condition in the discharge process because the output temperature of the PHE was much higher than the operating conditions. Finally, the decrement of the PCM thickness and the increment of the input temperature and flowrate of the heating fluid improved the heat transfer of the PHE; however, the main thermal resistance was still in the PCM.