Experimental determination of shell side heat transfer coefficient and pressure drop for an oil cooler shell-and-tube heat exchanger with three different tube bundles

In this paper, the heat transfer coefficient and pressure drop on the shell side of a shell-and-tube heat exchanger have been experimentally obtained for three different types of copper tubes (smooth, corrugated and with micro-fins). Also, experimental data has been compared with theoretical data available. Correlations have been suggested for both pressure drop and Nusselt number for the three tube types. A shell-and-tube heat exchanger of an oil cooler used in a power transformer has been modeled and built for this experimental work in order to investigate the effect of surface configuration on the shell side heat transfer as well as the pressure drop of the three types of tube bundles. The bundles with the same geometry, configuration, number of baffles and length, but with different external tube surfaces inside the same shell were used for the experiment. Corrugated and micro-fin tubes have shown degradation of performance at a Reynolds number below a certain value (Re < 400). At a higher Reynolds number the performance of the heat exchanger greatly improved for micro-finned tubes.