Experimental assessment of a PCM to air heat exchanger storage system for building ventilation applications

Abstract

PCM to air heat exchanger storage system is a solution to store energy in building ventilation system. In this work PCM to air heat exchanger storage experimental system has been developed and tested. The heat exchanger is tested in a open loop which provide constant air flow rates with temperature changes selected such that PCM is allowed to melt and solidify. The PCM used for heat exchanger is paraffin wax. The air velocity during charging and discharging is varied from 0.5 m/sec to 2 m/sec and wattage from 500 W to 1000 W. The results shows that increase in the air velocity leads to decrease the charging time as well as discharging time and thus agitates the charging and or discharging. At 1000 W, charging time reduces by 60% with increase in air velocity from 0.5 m/sec to 2 m/sec and at same wattage the discharging time reduces by 30% with increase in air velocity from 0.5 m/sec to 2 m/sec. This leads to conclusion that for fast charging and discharging can be achieved by increasing the air velocity.