Thermal/ exergy and economic efficiency analysis of circumferentially corrugated helical tube with constant wall temperature

Abstract

The effect of circumferential corrugations on the thermo-exergetic and economic efficiency of the helical tube is numerically studied for the first time. In the field of heat transfer enhancement, not only the heat transfer characteristics of the heat exchanger are important, but also the economic and financial issues play a key role. Hence, the present study is devoted to investigating both the thermal and economic advantages of using circumferential corrugations in a helical tube that has not been addressed in the literature before. In the present study, thermo-frictional properties of the circumferential corrugated tube as well as to PEC factor (Performance Evaluation Criteria) and Exergo-economic efficiency parameters are presented. Corrugations with three different pitch and depth were investigated. The tube wall had a constant temperature of 333.15 K. Results revealed that applying circumferential corrugation would lead to up to 1.54 times increment in the Nu number as well as 6.67 times increment of net profit per unit transferred heat load (ηp). Also, it was found that the total price of the unit transferred heat load (ηc) of a corrugated tube could be up to 9% less than that of a smooth tube.

Keywords

• Economic efficiency
• Whitte-shamsunder efficiency
• Nusselt number
• Performance evaluation criterion