Analysis of the heat transfer in double and triple concentric tube heat exchangers

The tubular heat exchangers (shell and tube heat exchangers and concentric tube heat exchangers) represent an important category of equipment in the petroleum refineries and are used for heating, pre-heating, cooling, condensation and evaporation purposes.The paper presents results of analysis of the heat transfer to cool a petroleum product in two types of concentric tube heat exchangers: double and triple concentric tube heat exchangers.The cooling agent is water.The triple concentric tube heat exchanger is a modified constructive version of double concentric tube heat exchanger by adding an intermediate tube.This intermediate tube improves the heat transfer by increasing the heat area per unit length.The analysis of the heat transfer is made using experimental data obtained during the tests in a double and triple concentric tube heat exchanger.The flow rates of fluids, inlet and outlet temperatures of water and petroleum product are used in determining the performance of both heat exchangers.Principally, for both apparatus are calculated the overall heat transfer coefficients and the heat exchange surfaces.The presented results shows that triple concentric tube heat exchangers provide better heat transfer efficiencies compared to the double concentric tube heat exchangers.