Comparing Between Thermal Performance of Coiled Tube and Straight Tube Inserted in a Cylindrical Reservoir in the Transient Convection Heat Transfer; Experimental Study

The main purpose of this study is to experimentally investigate transient convective heat transfer from a fluid stored inside a closed reservoir. Different cooling methods using helical and straight tubes are considered for heat transfer from the fluid reservoir. This paper attempts to determine the thermal advantages of helically coiled versus a straight tube. Fluid stored in the reservoir is cooled by water flow in the tube section at 27oC inlet temperature. The pressure drop and heat transfer parameters are measured over a wide range of Reynolds numbers (covers 500 to 5500). In these experiments, the effects of a couple of different parameters such as Reynolds number, time and geometrical parameters have been studied. Both heat transfer and pressure drop fluid flow in two test sections have been also reported and discussed. The experimental data indicate that using of helical coil instead of straight tube leads to increase heat transfer sharply. The coiled tube results show 42% reduction in of reservoir temperature compared to straight tube.