Abstract: The insert in a tube is one of the ways for heat transfer enhancement. But lots kind of the inserts cannot help to prevent or remove the fouling on the heat transfer surface. The heat transfer coefficient reduces and the energy consumes increase because of the fouling. But the hydraulic turbine in a heat ex-changer tube can realize the fouling preventing on-line and enhance heat transfer. The experimental and theoretical research is made on the heat transfer enhancement by the hydraulic turbine in a tube, and the experimental data of the friction and heat transfer are presented. After the analysis of the experimental results, the dimensionless correlations of the Nusselt number are given. The results show that the heat transfer enhances observably while the pressure loss is little by the hydraulic turbine. Even in contrast with the tube without foul and inset, the hydraulic turbine can enhance the heat transfer.

Key words: Fouling preventing on-line Heat transfer enhancement, Hydraulic turbine