A Rational Approach to Evaluate a Steam Turbine Rotor Grabbing and Locking Event

2007 ◽  
Author(s):  
Miguel Mattar Neto ◽  
Carlos Lueska
Keyword(s):  
Steam Turbine ◽  
High Speed ◽  
Failure Mechanisms ◽  
Turbine Rotor ◽  
Rational Approach ◽  
Reduction Gear ◽  
Production Plant ◽  
Electric Generator ◽  
Steam Turbine Rotor ◽  
Unique Event

In the paper, an unique event of a steam turbine rotor grabbing and locking will be described and evaluated. The turbine power is 21,740 kW and it is used in a pulp and paper production plant. The turbine is a high speed machine, 8,300 rpm, reaction multi-stage type, coupled by a reduction gear to a 4-pole electric generator, with 1,800 rpm. The steam turbine rotor grabbing and locking event evaluation is based on a proposed rational approach, i. e., based on the connection of the failure mechanisms observed and the identification of possible causes of these mechanisms. It is important to notice that the failure mechanisms and their causes are not the same. The failure mechanisms are the damages observed such as wear, fracture, severe deformation, etc. that impair or limit the safe and economical operation of a mechanical component. The causes, on the other hand, are the operational characteristics, the aging factors, the loads, etc. that introduce conditions to the failure mechanisms development. Using the proposed rational approach, the failure mechanisms causes that induce this unique event of steam turbine grabbing and locking are identified. Also, corrective and improvement actions based on the proposed rational approach are addressed to evaluate similar events and to avoid such a type of event in similar components.

Repair and Rejuvenation of a Severely Damaged 16-Stage Steam Turbine Rotor

2009 ◽  
Author(s):  
S. Ingistov ◽  
R. K. Bhargava ◽  
G. Doerksen
Keyword(s):  
Steam Turbine ◽  
High Speed ◽  
Repair Process ◽  
Turbine Rotor ◽  
Recent Experience ◽  
Replacement Cost ◽  
Flexible Rotor ◽  
Steam Turbine Rotor ◽  
Corrosion Pitting ◽  
Center Section

This paper describes the recent experience with the extensive overhaul and repairs of a long and flexible 16-stage steam turbine rotor of an integral design. An integral design steam turbine rotor is one where the shaft and disks are machined from a single forging. The steam turbine had sustained a crack at the base of the 11th stage disk as well as moderate to extensive corrosion pitting throughout the center section (stages 5 to 8) of the rotor. The rim of the 6th stage disk also required rebuilding because of the excessive damage due to corrosion and pitting. The steps required to optimize the repair process and minimize repair time as well as precautions taken during the repairs are discussed in this paper. To ensure reliability of the rebuild work, including newly manufactured blades for the 6th stage disk, stress analysis using Finite Element Method (FEM) was used to verify that stress levels are within acceptable limits in the blade’s root-to-dovetail groove, the results of such an analysis are included here. Finally, results of high speed balancing, critical for such a large flexible rotor are presented and discussed. This repair and rejuvenation work allowed salvaging the severely damaged rotor in approximately 5 months (compared to up to 2 years delivery for a new rotor) and at about one-fourth the rotor replacement cost.

Research on Precision Correcting for Heat Transfer Coefficient of Steam Turbine

2014 ◽  
Author(s):  
Yan Zhou ◽  
Danmei Xie ◽  
Yongxing Feng ◽  
Shi Liu
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Steam Turbine ◽  
High Speed ◽  
Thermal State ◽  
Turbine Rotor ◽  
Transfer Coefficients ◽  
Empirical Formulas ◽  
Steam Turbine Rotor

As a high-speed rotating part, forced convection of the surface of rotor is high-intensity when steam turbine is running. The thermal state of the rotor directly affects the distribution of the stress and vibration characteristics. In order to effectively monitor and control the thermal state of the rotor, heat transfer coefficient must be quickly and accurately calculated. Typically, different manufacturers select different empirical formulas and the calculated values vary greatly. Combining with empirical formulas, the accuracy of steam turbine rotor surface heat transfer coefficient is improved, so that the results become closer to the numerical calculation values, then also result in analyzing the thermal state of rotor more precisely. Taking a certain 300MW turbine rotor as an application, the heat transfer coefficients of rotor are analyzed and calculated. And the improved method can be also applied in a 600MW steam turbine rotor.

scholarly journals A linear cascade tunnel for flow investigations of steam turbine rotor tip blades in subsonic nucleating flows

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Vital Kumar Yadav Pillala ◽  
B. V. S. S. S. Prasad ◽  
N. Sitaram ◽  
M. Mahendran ◽  
Debasish Biswas ◽  
...  
Keyword(s):  
Steam Turbine ◽  
Turbine Rotor ◽  
Turbine Cascade ◽  
Flow Measurements ◽  
Linear Cascade ◽  
Dry Air ◽  
Steam Turbine Rotor ◽  
Pressure Distributions ◽  
Working Medium ◽  
Exit Mach Number

AbstractThe paper presents details of a unique experimental facility along with necessary accessories and instrumentation for testing steam turbine cascade blades in wet and nucleating steam. A steam turbine rotor tip cascade is chosen for flow investigations. Cascade inlet flow measurements show uniform conditions with dry air and steam and dry air mixture of different ratios. Exit flow surveys indicate that excellent flow periodicity is obtained. Blade surface static pressure and exit total pressure distributions are also presented with dry air and with steam and dry air mixture of different ratios as the working medium at an exit Mach number of 0.52.

scholarly journals On the creep fatigue and creep rupture behaviours of 9–12% Cr steam turbine rotor

2019 ◽  
Vol 76 ◽  
pp. 263-278 ◽  
Author(s):  
Xuanchen Zhu ◽  
Haofeng Chen ◽  
Fuzhen Xuan ◽  
Xiaohui Chen
Keyword(s):  
Steam Turbine ◽  
Turbine Rotor ◽  
Creep Rupture ◽  
Steam Turbine Rotor ◽  
Creep Fatigue

Effects of Laser Cladding Layers Width on Total Indicated Runout Characteristics of Steam Turbine Rotor Surface

2017 ◽  
Vol 46 (3) ◽  
pp. 612-616
Author(s):  
Guo Shirui ◽  
Shang Huichao ◽  
Cui Lujun ◽  
Guo Xiaofeng ◽  
Yao Jianhua
Keyword(s):  
Steam Turbine ◽  
Laser Cladding ◽  
Turbine Rotor ◽  
Steam Turbine Rotor ◽  
Rotor Surface ◽  
Cladding Layers

Research on Fault Diagnosis of Steam Turbine Rotor Unbalance and Parallel Misalignment Based on Numerical Simulation and Convolutional Neural Network

2021 ◽  
Author(s):  
Chongyu Wang ◽  
Di Zhang ◽  
Yonghui Xie
Keyword(s):  
Neural Network ◽  
Numerical Simulation ◽  
Fault Detection ◽  
Steam Turbine ◽  
Turbine Rotor ◽  
Detection Accuracy ◽  
Steam Turbine Rotor ◽  
Parallel Misalignment ◽  
Coupling Fault ◽  
The Impact

Abstract The steam turbine rotor is still the main power generation equipment. Affected by the impact of new energy on the power grid, the steam turbine needs to participate in peak load regulation, which will make turbine rotor components more prone to failure. The rotor is an important equipment of a steam turbine. Unbalance and misalignment are the normal state of rotor failure. In recent years, more and more attention has been paid to the fault detection method based on deep learning, which takes rotating machinery as the object. However, there is a lack of research on actual steam turbine rotors. In this paper, a method of rotor unbalance and parallel misalignment fault detection based on residual network is proposed, which realizes the end-to-end fault detection of rotor. Meanwhile, the method is evaluated with numerical simulation data, and the multi task detection of rotor unbalance, parallel misalignment, unbalanced parallel misalignment coupling faults (coupling fault called in this paper) is realized. The influence of signal-to-noise ratio and the number of training samples on the detection performance of neural network is discussed. The detection accuracy of unbalanced position is 93.5%, that of parallel misalignment is 99.1%. The detection accuracy for unbalance and parallel misalignment is 89.1% and 99.1%, respectively. The method can realize the direct mapping between the unbalanced, parallel misalignment, coupling fault vibration signals and the fault detection results. The method has the ability to automatically extract fault features. It overcomes the shortcoming of traditional methods that rely on signal processing experience, and has the characteristics of high precision and strong robustness.

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