The best angle of hot steam injection holes in the 3D steam turbine blade cascade

Steam turbines play an undeniable role in the power generation cycle. In this paper, in order to increase the efficiency of steam turbines, hot steam is injected between the steam turbine blades in 3D mode. Therefore, by defining five comparative criteria (liquid mass fraction, condensation loss, kinetic energy, hot steam injection ratio, and economic cost), injections with holes in various angles are investigated. For this purpose, the effects of the angle of the hot steam injection holes are discussed at the suction side on the two-phase flow parameters. The optimal angle for hot steam injection holes is selected (−60°), at which liquid mass fraction, condensation loss, and kinetic energy are reduced by 40%, 22%, and 1%, respectively. In addition, economic costs and hot steam injection holes are 0.56 ($/hour) and 0.07 for the suggested case.