Numerical Investigations of Tangential Direction Cooling in the Intermediate Pressure Cylinder (IPC)

Abstract

The cooling protection of the hot end is the key technique for ultra-supercritical steam turbine to cool the hot components. In this paper, the internal flow mechanism and cooling characteristics in the tangential direction cooling channel in the intermediate pressure cylinder (IPC) are investigated using the method of computational fluid dynamics. Various turbulence models and mesh sizes are evaluated (the k-ε model, the k-ω model, the SST model). Also, calculated results of the nonrotating bottom wall are compared with the experimental results in a previous research to show the reliability of the CFD program used. Detailed predictions of the contours of velocity, pressure and temperature are carried out. The focus of this study is to investigate the effects of inlet Mach number, turbulent Prandtl number, rotational wall speed, and inlet turbulence intensity on the cooling effectiveness of the vortex channel. The inlet Mach number, the turbulent Prandtl number, the rotational wall speed and the inlet turbulence intensity varied from 0.315 to 0.512, from 0.71 to 1.0, from 0 to 3000rpm, and from 1% to 10%, respectively. Results show that the parameters have different effects on the cooling effectiveness of the vortex cooling chamber. The cooling effect of the vortex channel increases with increasing inlet Mach number and rotational wall speed, while decreases with the increasing turbulent Prandtl number. As the inlet turbulence intensity increases, the cooling effect increases firstly, and then decreases.