Wetness and Losses Control Using Geometry Considerations in Low Pressure Stages of Steam Turbines

Mahmoud, N. H.; Singh, U. K.

doi:10.21608/erjm.2020.71330

Wetness and Losses Control Using Geometry Considerations in Low Pressure Stages of Steam Turbines

Document Type : Original Article

Authors

N. H. Mahmoud ¹
U. K. Singh ²

¹ Minufiya University, Shebin El-Kom, Egypt

² De Montfort University, Leicester, England

10.21608/erjm.2020.71330

Abstract

This paper is concerned with investigating the effects of some
geometrical characteristics of the cascade blades at low-pressure stages in
steam turbines on the wet steam flow behaviour. The present work is based
on a theoretical model combines a multistage three-dimensional semiviscous Euler solver with wet steam theory. Condensation of steam upon the
surface of water droplets through the model is obtained on the basis of
Lagrangian approach. Whilst the viscous effects in Euler solver are obtained
using a body force treatment based on a simple mixing-length model. The
blades geometrical characteristics is changed in the present study by cutting
the blade at the trailing edge zone vertically and horizontally, or by profiling
the blade end-wall. Present predictions show how the profiling of such a
blade trailing edge and end wall are used separately or together to adjust and
control both the flow behaviour and the situations of wetness accumulation.
The present model predictions are in good agreement with the available
experimental data.