A generic steam turbine exhaust diffuser with tip leakage modelling and non-uniform hood outlet

Authors

Z. Burton, G. Ingram, S. Hogg - Durham University, United Kingdom

Abstract

This paper advances the work of Burton et al. (2012) to highlight the significance of the last stage blade tip leakage jet on the flow structure in the low pressure (LP) steam turbine exhaust hood, widely regarded as being significant in other published research. The flow structure in the exhaust hood is distinctly asymmetric when the leakage jet is included due to the increased swirl. This paper offers the new contribution of the effect of the condenser on the flow structure within the exhaust hood. It has been shown that the pressure gradient at the condenser inlet due to the heating of the cooling water reduces the asymmetry caused by the tip leakage jet. Improvements have been made to Durham University’s public domain LP exhaust diffuser with accompanying last stage blades geometry to include the flare of the casing.