Experimental and Mathematical Research of Convection Heat Transfer for a High Integral Finned Tube Heat Exchanger

Abstract

Abstract This research exhibits an experimental and numerical investigation for the characteristics of heat transfer by utilizing an integral and smooth high finned tube and shows how the integral high fins affect in improving the transfer of heat. In the experimental work, the experimental rig consists of a cold water loop, a hot air loop and the trial part which is a concentric parallel flow double pipe heat exchanger. The first test smooth tube made of brass has external and internal diameter (32 mm) and (22 mm), respectively, the second test section made of the same material has external fins, the third test section possesses internal fins, and the fourth test section has internal and external fins. The dimensions of the fin are (2 mm) in thickness, (2 mm) in height and pitch (2.5 mm) center to center. And, the water flow rates are (6, 8, 10, 12 and 14 L/min). The inlet water to the trial tube was at temperatures (15, 25, 35, and 45oC). The investigational results manifested that the air side heat transfer coefficient of the smooth tube was lesser than the integral high finned tube. The ratio of improvement when using the integral high finned tube was (47.5%, 60.5% and 67.5 %). Numerical simulation was applied on the current heat exchanger to study both the transfer of heat and the field of flow by using ANSYS, FLUENT15 package. Steady state, Newtonian flow, incompressible and three dimensional analyses were assumed. The comparison between experimental work and numerical results elucidated a good agreement.