scholarly journals Steam Turbine Control Valve and Actuation System Modeling for Dynamics Analysis

2017 ◽  
Vol 105 ◽  
pp. 1651-1656 ◽  
Author(s):  
M. Pondini ◽  
A. Signorini ◽  
V. Colla
Keyword(s):  
Steam Turbine ◽  
System Modeling ◽  
Control Valve ◽  
Dynamics Analysis ◽  
Actuation System

Models of control valve and actuation system for dynamics analysis of steam turbines

2017 ◽  
Vol 207 ◽  
pp. 208-217 ◽  
Author(s):  
Maddalena Pondini ◽  
Valentina Colla ◽  
Annamaria Signorini
Keyword(s):  
Control Valve ◽  
Dynamics Analysis ◽  
Steam Turbines ◽  
Actuation System

Missile Roll Autopilot Redesign Based Advanced Fin Actuation System Modeling

2020 ◽  
Author(s):  
Sameh Fathey Shelan ◽  
Mohammed Abozied Hassan ◽  
Hossam Hendy ◽  
Yehia Zakarya Elhalwagy
Keyword(s):  
System Modeling ◽  
Actuation System

Numerical Simulation of Flow in Imported Steam Turbine Inlet Components with Equilibrated Holes in High Performance

2013 ◽  
Vol 712-715 ◽  
pp. 1263-1267
Author(s):  
Shan Tu ◽  
Shu Ming Wu ◽  
Qi Zhou ◽  
Hong Mei Zhang ◽  
Xiao Qing Zhu
Keyword(s):  
Flow Field ◽  
Steam Turbine ◽  
High Performance ◽  
Optimization Design ◽  
Great Influence ◽  
Control Valve ◽  
Stable Operation ◽  
Valve Seat ◽  
Valve Disc ◽  
Interior Flow

The main inlet component of steam turbine is control valve. The stable operation of the steam turbine control valve is vital for safe and stable operation of the steam turbine and safety production of the power plant. However, due to the complexity of the structure and unsteady characteristics of steam flow in the valve, there is not enough experimental method about the detailed flow characteristics of the area near control valve disc and the inside of the valve chamber up to now. This article is to focus on the simulation of the steam turbine control valve interior flow field which includes the valve pre-inlet channel in different conditions, then find the reasons which caused instability and pressure loss of the control valve by analyzing the flow field details, finally further optimization design. The profile matching of the valve disc and valve seat has a great influence on the interior flow field of control valve, so analysis of the high performance valve disc shape and divergence angle of valve seat is carried out, and the research conclusion is used for guide design and development of the control valve.

Scaling of Steam Turbine Control Valve Guidance Pins

2021 ◽  
Vol 58 (4) ◽  
pp. 216-223
Author(s):  
A. Neidel ◽  
E. Cagliyan ◽  
B. Fischer
Keyword(s):  
Steam Turbine ◽  
Control Valve ◽  
Oxidation Products ◽  
Control Valves ◽  
Common Scale

Abstract Severe scaling caused the guiding pin of two control valves of a smaller industrial steam turbine to seize which thus led to a malfunction. The customer sought clarification on whether the oxidation products are really common scale. This could be confirmed.

Optimal Control Theory Applied to a Pump With Single-Stage Electrohydraulic Servovalve

1988 ◽  
Vol 110 (2) ◽  
pp. 120-125 ◽  
Author(s):  
A. Akers ◽  
S. J. Lin
Keyword(s):  
Optimal Control ◽  
Control Theory ◽  
Optimal Control Theory ◽  
System Modeling ◽  
Control Valve ◽  
Open Loop ◽  
Single Stage ◽  
Response Curves ◽  
Electrohydraulic Valve ◽  
Comparison Of The Results

Optimal control theory is applied to the design of a pressure regulator for an axial piston pump and single-stage electrohydraulic valve combination. The control valve has been modeled and an optimal control law has been formulated. The time response curves due to a step input inflow rate and in current input to the servovalve have been obtained for the open loop and for the optimal control system. Comparison of the results has been made with previous work in which the supply valve to the swashplate actuators was not modeled. It is shown that controlled system modeling of the servovalve significantly improves system performance in terms of response frequency and pressure peaks.

Proper Orthogonal Decomposition and Extended- Proper Orthogonal Decomposition Analysis of Pressure Fluctuations and Vortex Structures Inside a Steam Turbine Control Valve

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Peng Wang ◽  
Hongyu Ma ◽  
Yingzheng Liu
Keyword(s):  
Proper Orthogonal Decomposition ◽  
Steam Turbine ◽  
Pressure Fluctuation ◽  
Pressure Field ◽  
Pressure Fluctuations ◽  
Control Valve ◽  
Vortex Structures ◽  
Orthogonal Decomposition ◽  
Pod Analysis ◽  
Proper Orthogonal

In steam turbine control valves, pressure fluctuations coupled with vortex structures in highly unsteady three-dimensional flows are essential contributors to the aerodynamic forces on the valve components, and are major sources of flow-induced vibrations and acoustic emissions. Advanced turbulence models can capture the detailed flow information of the control valve; however, it is challenging to identify the primary flow structures, due to the massive flow database. In this study, state-of-the-art data-driven analyses, namely, proper orthogonal decomposition (POD) and extended-POD, were used to extract the energetic pressure fluctuations and dominant vortex structures of the control valve. To this end, the typical annular attachment flow inside a steam turbine control valve was investigated by carrying out a detached eddy simulation (DES). Thereafter, the energetic pressure fluctuation modes were determined by conducting POD analysis on the pressure field of the valve. The vortex structures contributing to the energetic pressure fluctuation modes were determined by conducting extended-POD analysis on the pressure–velocity coupling field. Finally, the dominant vortex structures were revealed conducting a direct POD analysis of the velocity field. The results revealed that the flow instabilities inside the control valve were mainly induced by oscillations of the annular wall-attached jet and the derivative flow separations and reattachments. Moreover, the POD analysis of the pressure field revealed that most of the pressure fluctuation intensity comprised the axial, antisymmetric, and asymmetric pressure modes. By conducting extended-POD analysis, the incorporation of the vortex structures with the energetic pressure modes was observed to coincide with the synchronous, alternating, and single-sided oscillation behaviors of the annular attachment flow. However, based on the POD analysis of the unsteady velocity fields, the vortex structures, buried in the dominant modes at St = 0.017, were found to result from the alternating oscillation behaviors of the annular attachment flow.

On-Line Prediction of Temperature and Stress in Steam Turbine Components Using Neural Networks

2015 ◽  
Author(s):  
Krzysztof Dominiczak ◽  
Romuald Rządkowski ◽  
Wojciech Radulski ◽  
Ryszard Szczepanik
Keyword(s):  
Neural Networks ◽  
Steam Turbine ◽  
Power Plants ◽  
Control Valve ◽  
Turbine Rotor ◽  
Steam Turbine Rotor ◽  
On Line ◽  
Auto Regressive ◽  
Turbine Speed ◽  
Rotor Model

Considered here are Nonlinear Auto-Regressive neural networks with exogenous inputs (NARX) as a mathematical model of a steam turbine rotor used for the on-line prediction of turbine temperature and stress. In this paper on-line prediction is presented on the basis of one critical location in a high pressure steam turbine rotor, according to power plant common measurements, i.e., turbine speed, turbine load as well as steam temperature and pressure before turbine control valve. In order to obtain neural networks that will correspond to the temperature and stress the critical rotor location, an FE rotor model was built. Neural networks trained using the FE rotor model not only have FEM accuracy, but also include nonlinearity related to nonlinear steam turbine expansion, nonlinear heat exchange inside the turbine and nonlinear rotor material properties during transient conditions. Simultaneous neural networks are algorithms which can be implemented in turbine controllers. This allows for the application of neural networks to control steam turbine stress in industrial power plants.

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