Energy and Exergy Analysis of a Shell and Tube Heat Exchangers Having Smooth and Corrugated Inner Tubes

Abstract

Shell and tube heat exchangers are one of the most used heat exchanger types in applications and it is important to predict heat transfer capacity and pressure loss in both design stage. Heat transfer capacity of a heat exchanger can be enhanced by using tubes having enhanced surfaces instead of smooth ones. In this study, the usage of corrugated tubes in a shell and tube heat exchanger is investigated by using ε-NTU method, energy/exergy analysis. The impact of the usage of corrugated tubes on hot and cold fluid outlet temperatures, energy/exergy efficiencies, entropy generation and total exergy destruction are researched for various operation conditions. The results revealed that the difference between fluid outlet temperatures can be decreased by using tubes having corrugated surfaces instead of smooth ones because of fluid mixing and secondary flows obtained by means of the corrugations. Overall heat transfer coefficient of heat exchanger is enhanced up to 8% with the usage of corrugated tube in considered operation conditions. It is exhibited that the energy and exergy efficiencies of heat exchanger can be improved up to 18% and 16% with the usage of corrugated tubes instead of one having smooth tubes. Moreover, the entropy generation because of heat transfer and pressure loss and total exergy destruction of considered heat exchangers are determined to reveal the impact of corrugated tubes.

Exergy and Energy Analysis of the Shell-and-Tube Heat Exchanger for a Poultry Litter Co-Combustion Process

“…Thus, inlet and outlet exergy for both flue gas and water were calculated as shown in Equations ( 16) and (17). The exergy loss is expressed as the difference between the inlet and outlet exergy values of the streams, as shown in Equation (18).…”

“…EX d = Exergy loss = EX Feed − EX product (18) where C p,h = specific heat of flue gas; C p,w = specific heat of water;…”

“…Due to the widespread application of the STHE, it is necessary to improve its performance [16]. Previous studies have been carried out on exergy analysis of the STHE using graphene oxide nanofluids [17], hot water [18], and tap water [19], but limited research was performed to investigate the exergy analysis of the STHE using flue gas as a medium.…”