Energy and exergy analysis and optimization of helically grooved shell and tube heat exchangers by using Taguchi experimental design

Abstract

In this paper, for improvement of the performance of shell and tube heat exchanger, the effect of adding circular grooves on the shell of heat exchanger is considered numerically. The grooves are created in different heights but with the same pitch of the coil. The obtained results consist of both qualitative and quantitative data affected by geometrical parameters. According to the numerical results, the groove increases the heat transfer rate up to 5% and does not affect the pressure drop dramatically. By use of Taguchi experimental design and exergy analysis, the performance of the heat exchanger is examined in different working conditions, such as different level of cold inlet temperature, cold fluid flow rate, and groove height (roughness value). The results of this consideration revealed that the heat exchanger thermal efficiency varies from 23 to 49% in various conditions and also both the flow rate and the inlet temperature have the same effect on the exergy losses. The optimum groove height is presented equally to 10 mm.