Exergy analysis of porous cotton fabric drying process during the domestic air vented dryer

Abstract

This study reveals energy and exergy efficiencies of the fabric drying processes during air vented dryer. Exergy models of thedrying processes have been formed and each stage is examined in terms of exergetic parameters. Additionally, parametricstudies, including the exergy destruction rates, exergy efficiencies, and exergy loss ratios of the system and its components,have been investigated under various operating conditions. The results indicate that the exergy efficiency increases with theincrease in drying rate. Heater of dryer is the highest exergy destruction component of the whole dryer and its powersignificantly affects exergy destruction of whole drying process; while fan and motor of driving drum are lower exergydestruction component of dryer. Use of staged heating model of adjusting heater power based on drying period is found to be aneffective method to reduce the exergy destruction rate of dryer and fabric damage caused by over-drying. Specifically, exergyefficiency of dryer can be improved by increasing the heater power during the warm up and the constant rate period, or bydecreasing the drying-power during the falling rate and the blow-air period. The findings are found to be useful to systemdesign and performance optimization of domestic dryer in term of reducing irreversibility of the drying system.