Study of a thermoelectric space cooling system integrated with phase change material

Abstract

A thermoelectric cooling system integrated with phase change material (PCM) has been proposed for space cooling purpose, in which PCM stores cold thermal energy at night and functions as a heat sink to reduce hot side temperature of thermoelectric modules during daytime cooling period and thus improve the performance efficiency of the system. A numerical model for the PCM-integrated thermoelectric cooling system has been developed to analyze the entire system under two working modes: (1) dissipating the generated heat directly to outdoor air through the air–water heat exchanger (mode 1) and (2) releasing heat to the shell-and-tube PCM heat storage unit (mode 2). Experimental tests showed the average system cooling COP is increased by 56% (from 0.5 to 0.78) because of PCM integration. With the experiment validated numerical modeling, a comprehensive guide of the design procedure for the PCM-integrated thermoelectric space cooling system has been introduced. The thermoelectric cooling system is designed, as a case study, for an office room located in Denver, Colorado, from which two conclusions have been made: (1) the cooling power output, COP and cost are the most important three factors that determine the selection of thermoelectric modules (TEM) from market available products and (2) the accumulated heat dissipation of the cooling system determines the volume of PCM while local weather condition also needs to be evaluated to ensure PCM will be fully discharged at night.