Experimental analysis of heat transfer enhancement in shell and helical tube heat exchangers

In the present work attempts are made to enhance the heat transfer rate in shell and coiled tube heat exchangers experimentally. Hot water flows in helical tube and cold water flows in the shell side. Tube and shell side heat transfer coefficients are determined using Wilson plots. Experimental apparatus and Taguchi method are used to investigate the effect of fluid flow and geometrical parameters on heat transfer rate. After experiments, Taguchi method is used for finding the optimum condition for the desired parameters in the range of 0.0813 < D-c < 0.116, 13 < P-c < 18, tube and shell flow rates from 1 to 4 LPM. Then the optimum condition according to the overall heat transfer coefficient for the whole heat exchanger is found. Results indicate that the higher coil diameter, coil pitch and mass flow rate in shell and tube can enhance the heat transfer rate in these types of heat exchangers. Contribution ratio obtained by Taguchi method shows that shell side flow rate, coil diameter, tube side flow rate and coil pitch are the most important design parameters in coiled heat exchangers. (C) 2012 Elsevier Ltd. All rights reserved.