Numerical Study of Heat Transfer and Exergy Loss in a Double Tube Heat Exchanger with Corrugated Inner Tube: The New Configuration of Corrugated Tubes

In the present study, effect of the using corrugated tube (modified tube) as inner tube of a double tube heat exchanger on the heat transfer rate and exergy loss is numerically investigated. Each corrugation is made of a semi-circle with various diameters of 2.5, 5 and 7.5 mm, and a diagonal line. The inner tube of the heat exchanger is made of copper with inner diameter of 27 mm. The outer tube with inner diameter of 54.5 mm is considered isolated. The obtained results indicated that the use of corrugated tube as inner tube of heat exchanger had a significant effect on the heat transfer rate and exergy loss. Heat transfer in double tube heat exchangers with corrugated tubes was 1.07 to 3.08 times more than the transferred heat in a simple double tube heat exchanger. Furthermore, the effects of inlet hot water temperature and inlet cold water temperature on the exergy loss are studied. Based on acquired data, by increasing of the inlet hot water temperature or decreasing of the inlet cold water temperatures, exergy loss increases.