Simultaneous Effects of Hot Steam Injection and Surface Heating through an Embedded Channel of Steam Turbine Cascade

Abstract

One of the challenges of turbines in the last stages is the condensation of the water droplets of the steam flow; resisting against the droplets condensation could be one of the negative effects of the presence of droplets in the flow. The presence of droplets leads to erosion and damage to the blade as well as losses and efficiency drop in the turbine. Surface heating and hot steam injection are approaches suggested for solving the problem of droplets condensation; in the present study, a channel embedded in the turbine blade has been used to solve the problem of condensation. This is a step forward for making the hot steam injection and the blade surface heating practical. To prevent the condensation effects in the steam turbine cascade, two methods have been, simultaneously, utilized: surface heating and hot steam injection in a 3D study. As a result of applying the two heating methods mentioned, Er, Lr, and Wr decreased by 28.2%, 31.3%, and 61.5%, respectively. Moreover, the kinetic energy (one of the most important parameters in the turbine nozzle application) has increased by 0.35%. The results show a more surface temperature transfer on the blade's suction side.