Experimental and Numerical Investigation to Evaluate the Performance of U-Longitudinal Finned Tube Heat Exchanger

Abstract

The experimental and numerical investigation has been performed in this work to evaluate the performance of the U-longitudinal finned tube heat exchanger. Four pairs of U-shaped longitudinal fins were selected and manufactured from copper material and welded on the straight copper tube. The inner tube is inserted inside the insulated galvanized tube, and sheet and roll insulation (arm flux) and glass wool have been utilized to cover the inner and outer surface of the galvanized tube for reducing heat losses. Air at various mass flow rates (0.03 to 0.07)kg/sec flows through annuli and de-ionized water at Reynold's numbers ranging from (270 to 1900) flows through the inner tube. The performance of (smooth and finned) tube heat exchanger was investigated experimentally. Experimental results showed a (1.744 to 2.534) enhancement ratio when using U-longitudinal fins. Empirical correlations for air and water were represented by Nusselt's number. Numerical simulation has been carried out on the present heat exchanger to analyze flow field and heat transfer using FLUENT package 14. The comparison between experimental work and numerical results showed good agreement.