scholarly journals Flutter Analysis of Last Stage Steam Turbine Power Plant Blade Through Transient Blade Row Simulation

2021 ◽  
Vol 1096 (1) ◽  
pp. 012093
Author(s):  
A R Laksana ◽  
A M Kokong ◽  
P Agus Sigit ◽  
T Widjajanto ◽  
H Setiawan ◽  
...  
Author(s):  
Christopher Fuhrer ◽  
Marius Grübel ◽  
Damian M. Vogt ◽  
Paul Petrie-Repar

Turbine blade flutter is a concern for the manufacturers of steam turbines. Typically, the length of last stage blades of large steam turbines is over one meter. These long blades are susceptible to flutter because of their low structural frequency and supersonic tip speeds with oblique shocks and their reflections. Although steam condensation has usually occurred by the last stage, ideal gas is mostly assumed when performing flutter analysis for steam turbines. The results of a flutter analysis of a 2D steam turbine test case which examine the influence of non-equilibrium wet steam are presented. The geometry and flow conditions of the test case are supposed to be similar to the flow near the tip in a steam turbine as this is where most of the unsteady aerodynamic work contributing to flutter is done. The unsteady flow simulations required for the flutter analysis are performed by ANSYS CFX. Three fluid models are examined: ideal gas, equilibrium wet steam (EQS) and non-equilibrium wet steam (NES), of which NES reflects the reality most. Previous studies have shown that a good agreement between ideal gas and EQS simulations can be achieved if the prescribed ratio of specific heats is equal to the equilibrium polytropic index of the wet steam flow through the turbine. In this paper the results of a flutter analysis are presented for the 2D test case at flow conditions with wet steam at the inlet. The investigated plunge mode normal to chord is similar to a bending mode around the turbine axis for a freestanding blade in 3D. The influence of the overall wetness fraction and the size of the water droplets at the inlet are examined. The results show an increase of aerodynamic damping for all investigated interblade phase angles with a reduction of droplet size. The influence of the wetness fraction is in comparison of less importance.


2019 ◽  
Vol 137 ◽  
pp. 01002
Author(s):  
Radosław Bondyra ◽  
Krzysztof Dominiczak ◽  
Jacek Matuszak

This article concerns a reverse engineering-based design process of last stage blade (LSB) for other original equipment manufacturer (oOEM). For Loviisa Power Plant (Finland) GE designed and delivered a set of oOEM LSBs to be fit into existing low pressure (LP) turbine module steam path. Although cost competitiveness is a one of major selection criterion for steam turbine spare parts components supplier, diversification of suppliers is also a strategic for power plant owner. Considered here is a process of reengineering of oOEM LSB and all relevant challenges related to this process especially management of geometry deviations between reverse-engineered and oOEM blade. In this article, there are a design steps described taken to qualify reverse-engineered design. Moreover, a manufacturing process of the LSB is shown.


Author(s):  
Paul Petrie-Repar ◽  
Vasily Makhnov ◽  
Nikolay Shabrov ◽  
Evgueni Smirnov ◽  
Sergey Galaev ◽  
...  

An advanced flutter analysis of a final stage turbine row with a new 1.2 meter long shrouded blade is presented. The three-dimensional (3D) unsteady Reynolds Averaged Navier-Stokes (URANS) equations with the Spalart and Allmaras turbulence model were employed to model the flow. The flow entering the last stage is a mixture of saturated vapor and liquid. An equilibrium wet-steam equation of state was used to model the properties of the mixture. Multi-row steady state simulations of the upstream stator row, the turbine row and the extended exhaust section were performed. It was considered important to include the exhaust section in the steady-state simulations in order to accurately predict the pressure profile at the exit of the turbine. The flow simulations were relatively high resolution and the single passage turbine mesh had 798 208 cells. Linearized flow simulations for the turbine row were performed to determine the unsteady aerodynamic work on the blades for the possible aeroelastic modes. An exact 3D non-reflecting boundary condition (3D-NRBC) was applied at the inlet and outlet for the linearized flow simulations to eliminate non-physical reflections at these boundaries. The calculated logarithmic decrement values for the new turbine blade are compared with a reference case for a similar steam turbine blade at a condition known to have a long and safe working history. The new last stage was found to be more stable than the reference case at the flow condition examined.


2021 ◽  
Vol 1096 (1) ◽  
pp. 012097
Author(s):  
A M Kongkong ◽  
H Setiawan ◽  
J Miftahul ◽  
A R Laksana ◽  
I Djunaedi ◽  
...  

1976 ◽  
Vol 98 (3) ◽  
pp. 573-577 ◽  
Author(s):  
J. Krzyz˙anowski ◽  
B. Weigle

In a series of experiments aimed at the visualization of the wet steam flow in the exhaust part of a 200 MW condensing steam turbine a set of periscopes and light sources was used. The aim of the experiment was: 1 – The investigation of the liquid-phase flow over the last stage stator blading of the turbine mentioned. 2 – The investigation of the gaseous-phase flow through the last stage blading at full and part load. The first part of the program partially failed due to the opaqueness of the wet steam atmosphere for the turbine load higher than 10–20 MW. The detailed experimental conditions will be described. An assessment of the primary droplet size will also be given. The preliminary results of the second part of the program will be outlined. The advantages and disadvantages of the equipment used will be discussed.


Author(s):  
Akili D. Khawaji ◽  
Jong-Mihn Wie

The most popular method of controlling sulfur dioxide (SO2) emissions in a steam turbine power plant is a flue gas desulfurization (FGD) process that uses lime/limestone scrubbing. Another relatively newer FGD technology is to use seawater as a scrubbing medium to absorb SO2 by utilizing the alkalinity present in seawater. This seawater scrubbing FGD process is viable and attractive when a sufficient quantity of seawater is available as a spent cooling water within reasonable proximity to the FGD scrubber. In this process the SO2 gas in the flue gas is absorbed by seawater in an absorber and subsequently oxidized to sulfate by additional seawater. The benefits of the seawater FGD process over the lime/limestone process and other processes are; 1) The process does not require reagents for scrubbing as only seawater and air are needed, thereby reducing the plant operating cost significantly, and 2) No solid waste and sludge are generated, eliminating waste disposal, resulting in substantial cost savings and increasing plant operating reliability. This paper reviews the thermodynamic aspects of the SO2 and seawater system, basic process principles and chemistry, major unit operations consisting of absorption, oxidation and neutralization, plant operation and performance, cost estimates for a typical seawater FGD plant, and pertinent environmental issues and impacts. In addition, the paper presents the major design features of a seawater FGD scrubber for the 130 MW oil fired steam turbine power plant that is under construction in Madinat Yanbu Al-Sinaiyah, Saudi Arabia. The scrubber with the power plant designed for burning heavy fuel oil containing 4% sulfur by weight, is designed to reduce the SO2 level in flue gas to 425 ng/J from 1,957 ng/J.


2013 ◽  
Vol 34 (4) ◽  
pp. 51-71 ◽  
Author(s):  
Paweł Ziółkowski ◽  
Dariusz Mikielewicz ◽  
Jarosław Mikielewicz

Abstract The objective of the paper is to analyse thermodynamical and operational parameters of the supercritical power plant with reference conditions as well as following the introduction of the hybrid system incorporating ORC. In ORC the upper heat source is a stream of hot water from the system of heat recovery having temperature of 90 °C, which is additionally aided by heat from the bleeds of the steam turbine. Thermodynamical analysis of the supercritical plant with and without incorporation of ORC was accomplished using computational flow mechanics numerical codes. Investigated were six working fluids such as propane, isobutane, pentane, ethanol, R236ea and R245fa. In the course of calculations determined were primarily the increase of the unit power and efficiency for the reference case and that with the ORC.


Author(s):  
Wancai Liu ◽  
Hui Zhang

Gas turbine is widely applied in power-generation field, especially combined gas-steam cycle. In this paper, the new scheme of steam turbine driving compressor is investigated aiming at the gas-steam combined cycle power plant. Under calculating the thermodynamic process, the new scheme is compared with the scheme of conventional gas-steam combined cycle, pointing its main merits and shortcomings. At the same time, two improved schemes of steam turbine driving compressor are discussed.


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