CFD analysis of a single stage intermediate pressure steam turbine

Abstract

A steam prime mover with rotary motion of the driving element, or rotor, and continuous operation. It converts the thermal energy of steam into mechanical work. The steam flow proceeds through directing devices and impinges on curved blades mounted along the periphery of the rotor. By exerting a force on the blades, the steam flow causes the rotor to rotate. Unlike the reciprocating steam engine, the steam turbine makes use of the kinetic rather than the potential energy of steam. The performance of the turbine depends on the efficient conversion of steam enthalpy into mechanical power with minimum flow losses. In order to reduce the leakage loss hub/shroud sealing between the stages is considered. The hub/shroud sealing improves the performance of the turbine and higher power is generated from the stages. To simulate the hub/shroud sealing, blades & seals are modelled and meshed separately. The bladed region and hub/shroud seal region are attached by General Grid Interface. The flow domain and mesh generation for seal area needs to be accurate to get the correct interface with blades.