Investigation on phase change material-based flat plate heat exchanger modules for free cooling applications in energy-efficient buildings

ABSTRACT

A phase change material (PCM)-based flat plate heat exchanger has been developed for free cooling of buildings. It has several PCM modules with an air passage between one module and another. The performance of this heat exchanger is analysed using FLUENT software on the symmetric portions of two PCM modules and an air passage. The apparent heat capacity method is used to model the latent heat value of the PCM, and the profile obtained from the digital scanning calorimeter analysis is suitably approximated. The charging and discharging characteristics of the PCMs at various velocities and inlet temperatures of the air are also analysed. The results of charging analysis are compared with the experimental results. The time-wise variation of the temperature of the PCM and air, instantaneous and cumulative heat transfer during the charging and discharging processes for various parameters of interest are reported. The results are very useful for the architects and building engineers in designing energy-efficient buildings.

Abbreviations: CFD: computational fluid dynamics; DSC: digital scanning calorimeter; HTF: heat transfer fluid; LHTES: latent heat thermal energy storage; PCM: phase change material; RTD: resistance temperature detector

KEYWORDS:

• Free cooling
• latent heat thermal energy storage
• CFD analysis
• PCM
• energy-efficient buildings