THE COPPERBELT UNIVERSITY SCHOOL OF MINES AND MINERAL SCIENCES DEPARTMENT OF CHEMICAL ENGINEERING NAME : DANIEL CHEWE MPUNDU COMP# : 14332356 PROG : BsC OF ENGINEERING IN CHEMICAL ENGINEERING TASK : EXPERINMENT #7 INSTRUCTOR : MR CHIPILI DUE DATE : 7 th MARCH 2017 SCHOOL : SMMS
TITLE: CONSTANT AREA FIN OBJECTIVE: To determine the transfer coefficient between the ambient air and the fin ABSTRACT: INTRODUCTION: Fins or extended surfaces are projections which stick out to ambient surroundings of surfaces to aid heat transfer when an available surface is found inadequate to transfer the required quantity of heat with the available temperature drop and convective heat transfer coefficient. One application of fins is observed in radiators of automobiles and air cooled engine cylinder heads Heat transfer is the study of the rates of heat exchange as they occur in heat transfer equipment. From the equation below; Q = UA ΔT LMTD , Where ΔT LMTD = logarithmic mean temperature difference, A = mean surface area (πDl), U = overall heat transfer coefficient, It can be seen that for a given heat transfer coefficient and given fluid temperature, The convective removal of heat from a surface can be substantially improved by increasing the heat transfer area. One way of doing this, is to increase the area on one side of the heat exchanger by adding extensions on that surface which projects into the fluid; the effective heat transfer area is then increased. These extensions can take various forms. There are many ways in which the surface of commercial heat exchange tubing can be extended with protrusions of a kind we call a fin. A fin is an extended surface; protruding from a surface of a metal or wall etc. these extended surfaces are employed to increase the heat transfer rates from a solid to the surrounding fluid. The thermal resistance on either sides of the heat exchanger is given by, 1/ (hA), where h = heat transfer coefficient, Therefore, when h is very large, the resistance to heat transfer is low and hence there is no advantage in increasing the area, one of the fluids usually has a much lower value of h than the other and hence the resistance on this side of the heat exchanger controls the heat transfer. It is therefore on this side that the area can be extended with advantage. In order
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