Enhancement of Heat Transfer Coefficient through Forced Convection Apparatus by Using Circular and Elliptical Pipe

Abstract

It is very essential to develop a forced convection system to carry out the analytical and experimental investigation of the heat transfer coefficient with the use of the elliptical and circular pipe. Convection is nothing but the transfer of heat through a fluid which is in bulk fluid motion. Depending on the motion of the fluid, it is classified as natural and forced convection. Buoyancy effect is the natural cause which occurs due to fluid motion in natural convection. On the other hand, in forced convection, the motion of the fluid is caused by external means like a pump or fan. In this system three, 130 Volt heaters are wounded over 800 mm test section of Circular pipe having a 25mm diameter and Elliptical pipe having 22 mm minor and 28 mm major diameter. Variable dimmer stat is used to control input to heater and control valve to control mass flow rate, to determine the average coefficient of heat transfer in turbulent flows inside smooth and straight Circular and Elliptical pipes. The research consists of a regression analysis performed between the Reynolds number and the Prandtl number finally to calculate the heat transfer coefficient of Circular and Elliptical pipes by experimental investigation. After calculating all the results of both the pipes finally we got that efficiency of Elliptical pipe is more than circular pipe also heat transfer coefficient is maximum in the elliptical pipe than the circular pipe and it also led to increasing the heat transfer rates. The deviation of the heat transfer coefficient is maximum as compared to Elliptical pipe.

Justification of efficiency of plain shaped heat exchange surfaces to increase the compactness of power plants

“…The works [9,10] present the results of comparative experimental studies of circular and elliptical tubes in the range of numbers Re=6,000...11,000 with an internal flow. Comparison of the obtained experimental data with the results of theoretical calculations using the Dittus-Boelter equation is shown.…”