Fatigue failure analysis of last stage blade in a low pressure steam turbine

1999 ◽  
Vol 6 (2) ◽  
pp. 93-100 ◽  
Author(s):  
Hyo-Jin Kim
Keyword(s):  
Failure Analysis ◽  
Steam Turbine ◽  
Fatigue Failure ◽  
Low Pressure ◽  
Pressure Steam ◽  
Last Stage

scholarly journals Failure Analysis in Lacing Wire Of Last Stage Low Pressure Steam Turbine Blade

2021 ◽  
Vol 1096 (1) ◽  
pp. 012097
Author(s):  
A M Kongkong ◽  
H Setiawan ◽  
J Miftahul ◽  
A R Laksana ◽  
I Djunaedi ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Steam Turbine ◽  
Turbine Blade ◽  
Low Pressure ◽  
Pressure Steam ◽  
Steam Turbine Blade ◽  
Last Stage

Sequential vs Multidisciplinary Coupled Optimization and Efficient Surrogate Modelling of a Last Stage and the Successive Axial Radial Diffuser in a Low Pressure Steam Turbine

2014 ◽  
Author(s):  
Kevin Cremanns ◽  
Dirk Roos ◽  
Arne Graßmann
Keyword(s):  
Steam Turbine ◽  
Design Process ◽  
Energy Demand ◽  
Three Dimensional ◽  
Flow Simulation ◽  
Low Pressure ◽  
Steam Turbines ◽  
Low Pressure Turbine ◽  
Pressure Steam ◽  
Last Stage

In order to meet the requirements of rising energy demand, one goal in the design process of modern steam turbines is to achieve high efficiencies. A major gain in efficiency is expected from the optimization of the last stage and the subsequent diffuser of a low pressure turbine (LP). The aim of such optimization is to minimize the losses due to separations or inefficient blade or diffuser design. In the usual design process, as is state of the art in the industry, the last stage of the LP and the diffuser is designed and optimized sequentially. The potential physical coupling effects are not considered. Therefore the aim of this paper is to perform both a sequential and coupled optimization of a low pressure steam turbine followed by an axial radial diffuser and subsequently to compare results. In addition to the flow simulation, mechanical and modal analysis is also carried out in order to satisfy the constraints regarding the natural frequencies and stresses. This permits the use of a meta-model, which allows very time efficient three dimensional (3D) calculations to account for all flow field effects.

Prediction of losses in the flow through the last stage of low-pressure steam turbine

2007 ◽  
Vol 53 (6) ◽  
pp. 933-945 ◽  
Author(s):  
Slawomir Dykas ◽  
Włodzimierz Wróblewski ◽  
Henryk Łukowicz
Keyword(s):  
Steam Turbine ◽  
Low Pressure ◽  
Pressure Steam ◽  
Flow Through ◽  
Last Stage

Aerodynamic Interaction Effects From Upstream and Downstream on the Down-Flow Type Exhaust Diffuser Performance in a Low Pressure Steam Turbine

2013 ◽  
Author(s):  
Tadashi Tanuma ◽  
Yasuhiro Sasao ◽  
Satoru Yamamoto ◽  
Yoshiki Niizeki ◽  
Naoki Shibukawa ◽  
...  
Keyword(s):  
Steam Turbine ◽  
Low Pressure ◽  
Interaction Effects ◽  
Wet Steam ◽  
Inlet Flow ◽  
Flow Type ◽  
Diffuser Flow ◽  
Aerodynamic Interaction ◽  
Pressure Steam ◽  
Last Stage

The purpose of this paper is to explain aerodynamic interaction effects from upstream and downstream on the down-flow type exhaust diffuser performance in a low pressure steam turbine. To increase exhaust diffuser performance, design data related to the aerodynamic interaction effects from upstream turbine stages and downstream exhaust hood geometry on the exhaust diffuser performance would be very useful. This paper presents numerical investigation of three dimensional wet steam flows in a down-flow type exhaust diffuser with non-uniform inlet flow from a typical last stage with long transonic blades designed with recent aerodynamic and mechanical design technology. Previous studies show that small scale model tests and CFD analyses of exhaust diffusers with uniform inlet flow conditions are not enough to investigate diffuser efficiency and detail diffuser flow mechanism because inlet flow structures including tip leakage flows and blade wakes superimposed from a last stage and several other upstream turbine stages in low pressure turbines affect flow separations that reduce the exhaust diffuser performance. Recent studies by the authors show that the introduction of radial distributions of velocities and flow angles at the inlet section of exhaust diffuser measured in a full scale development steam turbine increased the accuracy of numerical analysis of diffuser flow. In the present study, the computational domain was enhanced and the method of boundary condition definition was improved to increase the accuracy of boundary layer separation and separation vortex generation in wet steam flows. Using the improved method, the calculation results explained the aerodynamic interaction effects from upstream and downstream on the down-flow type exhaust diffuser performance.

A 3D method to evaluate moisture losses in a low pressure steam turbine: Application to a last stage

2015 ◽  
Vol 84 ◽  
pp. 642-652 ◽  
Author(s):  
Xinggang Yu ◽  
Zhihuai Xiao ◽  
Danmei Xie ◽  
Chun Wang ◽  
Cong Wang
Keyword(s):  
Steam Turbine ◽  
Low Pressure ◽  
Pressure Steam ◽  
Last Stage

Effect of Steam Injection on Last-Stage Blade Temperature of Low Pressure Steam Turbine at Low Volume Flow Condition

2017 ◽  
Author(s):  
Can Ma ◽  
Jun Wu ◽  
Yuansheng Lin
Keyword(s):  
Steam Turbine ◽  
Nuclear Power ◽  
Reverse Flow ◽  
Three Dimensional ◽  
Steam Injection ◽  
Low Pressure ◽  
Volume Flow ◽  
Pressure Steam ◽  
Last Stage ◽  
Low Volume

In the nuclear power plant, the last stage of the low pressure steam turbine is characterized by long blades. These long blades operate under severe working conditions with wet steam flow and strong mechanical stress. At the start up and shut down operating condition where the volume flow is extremely low, the last stage blades operate in ventilation conditions where there is significant reverse flow in the exhaust and the last stage. In such a condition, the reverse flow would cause significant increase in the blade temperature. In addition, the rotating reverse flow would increase the vibration of the rotor blade. Such temperature increase and enhanced vibration can cause blade damage and force the machine to be shut down. In previous work, the steam injection in the last stage has been proposed as a promising method to decrease the reverse flow at low volume flow conditions, which reduces the stall cell size in the last stage blade. This work investigates the effect of the steam injection process on the blade temperature distribution by conducting three-dimensional flow simulations. Various steam injection configurations are compared in this work and the major consideration to be noted in the design process is discussed.

Dynamic Analysis of Low-Pressure Steam Turbine Last Stage Fir-Tree Root Blade

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Rajesh K. Bhamu ◽  
Aakash Shukla ◽  
Satish C. Sharma ◽  
S. P. Harsha
Keyword(s):  
Steam Turbine ◽  
Low Pressure ◽  
Crack Size ◽  
Pressure Steam ◽  
Element Approach ◽  
Steam Turbine Blade ◽  
Stiffness Variation ◽  
Last Stage ◽  
Excitation Pattern ◽  
Rotor Assembly

Abstract In the present study, the dynamic behavior of the last stage low-pressure steam turbine blade with fir-tree root at different conditions of blade root flank faces and their interfaces with rotor groove have been analyzed. Modal analysis has been done using a finite element approach to evaluate natural frequencies and evaluation of Campbell diagram generated under these conditions. For this, both healthy and defective blade have been taken. Since the variable crack size of fir-tree root flank has been taken, the excitation pattern has been evaluated due to stiffness variation of the cracked blade. This analysis provides the basis of excitation pattern of cracked blades due to inherent character and critical stressed zone. The outcome of this study forms the guidelines and checks during the fitting of blades in rotor assembly and its checks during health audit, overhaul, overspeed balancing test, and frequency turning.

scholarly journals Failure Analysis of 2Cr13 Blade in a 135MW Low Pressure Steam Turbine

2020 ◽  
Vol 526 ◽  
pp. 012144
Author(s):  
Hai Zhao ◽  
Chong Jiang ◽  
Zhiwei Gao ◽  
Bing Hu ◽  
Chengchuan Tian
Keyword(s):  
Failure Analysis ◽  
Steam Turbine ◽  
Low Pressure ◽  
Pressure Steam
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