Discharging process and performance of a portable cold thermal energy storage panel driven by embedded heat pipes

Abstract

By recent interest in overcoming heat transfer limitations of phase change materials (PCMs), latent thermal energy storage devices that assisted by embedded heat pipes (HPs) have received much attentions. Due to coupling with HPs, phase change process of PCMs can be enhanced and be better managed. In this study, a cold thermal energy storage panel for portable applications that embedded HPs into PCM is investigated experimentally. An effective way to control the cold energy supply of the panel is to control air temperature and air velocity. However, air properties varied with temperature as well as layout of HPs in the airside have influence on energy supply, which is implicit to the control of the panel. Therefore, the average effectiveness-NTU method is utilized to indicate the connection between air properties to the cold energy supply performance. The model validation results show that the effectiveness-NTU technique can describe the variation of refrigeration capacity with inlet air temperature and air velocity. The calculation error of the model is below ±9.0%. This method can be used as a design tool and is expected to provide a framework for designing portable cold thermal energy storage device with manageable cold energy supply.