Control of the probe influence on the flow field in LP steam turbine

For measuring the fine droplets properties in the wet steam expanding in the steam turbines the light extinction probes are usually used. The paper presents CFD modelling of the extinction probe influence on the wet steam flow field at the measurement position. The aim is to get a basic information about the influence of the flow field deviation on the measured data, in other words, of necessity to correct the measured data. The basic modelling procedure is described, as well as the supposed simplifications and the factor considering the change in the steam density in the measuring slot of the probe. The model is based on the experimental data that were achieved during the developmental measurements in the steam turbine 1090 MW in the power station Temelín. The experimental measurement was done in the cooperation with the Doosan Škoda Power s.r.o

A CFD Analysis of Steam Flow in the Two-Stage Experimental Impulse Turbine with the Drum Rotor Arrangement

The aim of the paper is to present the CFD analysis of the steam flow in the two-stage turbine with a drum rotor and balancing slots. The balancing slot is a part of every rotor blade and it can be used in the same way as balancing holes on the classical rotor disc. The main attention is focused on the explanation of the experimental knowledge about the impact of the slot covering and uncovering on the efficiency of the individual stages and the entire turbine. The pressure and temperature fields and the mass steam flows through the shaft seals, slots and blade cascades are calculated. The impact of the balancing slots covering or uncovering on the reaction and velocity conditions in the stages is evaluated according to the pressure and temperature fields. We have also concentrated on the analysis of the seal steam flow through the balancing slots. The optimized design of the balancing slots has been suggested

A shape modification of the balancing slot of the impulse turbine stage with the drum rotor arrangement

At the previous conference in Český Krumlov it was presented how the balancing slots may influence the efficiency of the impulse turbine stage with the drum rotor arrangement. A few options for shape modification of the balancing slot were also suggested. Implementation of the balancing slots and their possible modifications are subject to various design and technological limitations. During the consultation with the turbine designers and technologists, we were able to determine the modification of the balancing slot which, in terms of their design and production technology, will be the most simple and feasible. It is predicted that the suggested shape modification of the balancing slot will improve the efficiency of the turbine stage. This prediction is then supported by CFD simulations

A CFD Analysis of Steam Flow in the Two-Stage Experimental Impulse Turbine with the Drum Rotor Arrangement

The aim of the paper is to present the CFD analysis of the steam flow in the two-stage turbine with a drum rotor and balancing slots. The balancing slot is a part of every rotor blade and it can be used in the same way as balancing holes on the classical rotor disc. The main attention is focused on the explanation of the experimental knowledge about the impact of the slot covering and uncovering on the efficiency of the individual stages and the entire turbine. The pressure and temperature fields and the mass steam flows through the shaft seals, slots and blade cascades are calculated. The impact of the balancing slots covering or uncovering on the reaction and velocity conditions in the stages is evaluated according to the pressure and temperature fields. We have also concentrated on the analysis of the seal steam flow through the balancing slots. The optimized design of the balancing slots has been suggested