OPTIMIZATION OF FREE COOLING SYSTEMS USING MULTIPLE PCM LATENT HEAT THERMAL STORAGE UNIT

摘要

A numerical investigation is reported of the performance enhancement of a free cooling system using a latent heat thermal storage (LHTS) unit employing multiple phase change materials (PCMs). The LHTS system consists of several flat PCM slabs arranged in layers with passages in between for air. Using COMSOL Multiphysics software, the process of melting and solidification of the PCM is predicted. The energy storage effectiveness (a new performance parameter for LHTS units) and coefficient of performance (COP) of the system are calculated. These two performance indicators are used to optimize the system. The suitability of both methods for optimization purposes is discussed, and the energy based (COP) method is indicated to be superior.