Experimental Study of Heat Transfer in Alternating Elliptical Tubes in a Double-Tube Heat Exchanger

Document Type : Original Research Article

Authors

1 Department of mechanical engineering Shahrekord university,Shahrekord,Iran

2 Department of Mechanical Engineering, Shahrekord University, Shahrekord, Iran

Abstract

In this paper, the thermal and hydrodynamic behavior of alternating elliptical tubes in a double-pipe heat exchanger has been introduced and examined. The experiments were conducted in the Reynolds range of 200 to 1200, and the results were calculated using the statistical method of the confidence interval with 95 percent accuracy. Experimental results show that the heat transfer rate and pressure drop of alternating elliptical tubes are higher than those of circular tubes, and with a decrease in pitch length and an increase in flattening at a constant tube length, both heat transfer and pressure drop increase. It was also determined that the heat transfer rate of the alternating elliptical tube with the same flatness and a pitch of 120 millimeters is approximately 1.05 and the pressure drop is approximately 1.03 times that of the alternating elliptical tube with a pitch of 280 millimeters. Additionally, the heat transfer rate of the alternating elliptical tube with the same pitch and a flatness of 10 mm was approximately 1.15, and the pressure drop was approximately 1.11 times that of the alternating elliptical tube with a flatness of 12 mm. Finally, it was concluded that the heat transfer rate of the alternating elliptical tube with pitch and flattening of 10-120 mm, 10-280 mm, and 12-120 mm is approximately 2.30, 2.20, and 2 times, respectively, and the pressure drop is 1.33, 1.29, and 1.2 times that of the circular tube.

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