scholarly journals Frequency analysis of signal obtained from pressure probe during measurement at the steam turbine control valve

2021 ◽  
Author(s):  
Petr Kollross ◽  
Ladislav Tajč
Keyword(s):  
Steam Turbine ◽  
Frequency Analysis ◽  
Control Valve ◽  
Pressure Probe

Forced Response Analysis of Steam Turbine Inlet Flow Control Valves

2014 ◽  
Author(s):  
Suryarghya Chakrabarti ◽  
Yogesh Potdar ◽  
Sanghum Baik ◽  
David Welch ◽  
Guido Forte
Keyword(s):  
Steam Turbine ◽  
Coupled Model ◽  
Control Valve ◽  
Forced Response ◽  
Symmetric System ◽  
Pressure Probe ◽  
Response Analysis ◽  
Worst Case ◽  
Finite Element Software ◽  
Operation Conditions

This work presents a comparison of two forced response methodologies implemented in commercial finite element software Ansys for describing the dynamic structural response of a steam turbine combined stop and control valve assembly in realistic operation conditions. The first method employs one-way coupling where the pressure field of a selected acoustic mode from an acoustic modal analysis on the valve cavity is scaled based on a pressure probe measurement and mapped onto the structure followed by a harmonic forced response analysis at the structure natural frequency. This method is called the decoupled model — it is fast and conservative as it assumes the acoustic and the structure modes to coincide providing a worst-case forced response estimate. The second method employs two-way coupling between acoustics and structure vibration. It takes five to ten times longer to run than the decoupled model because of the presence of non-symmetric system matrices and must be run multiple times with inputs spanning the operating condition range. However, the coupled model provides the opportunity for a more optimal design as it does not assume the acoustic and structure modes to line up. For the valve geometry studied in this work the effect of two-way coupling seems significant in some conditions where it can cause changes of up to 50% in the forced response.

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.

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.

Steam Turbine Control Valve Noise

1973 ◽  
Vol 54 (1) ◽  
pp. 289-289 ◽  
Author(s):  
Frank J. Heymann ◽  
Michael A. Staiano
Keyword(s):  
Steam Turbine ◽  
Control Valve

Economic Analysis for Nozzle Governing With Overload Valve Regulation Technology

2017 ◽  
Author(s):  
Jing Fangbo ◽  
Lai Qiang ◽  
Wei Dongliang ◽  
Chen Xianhui ◽  
Yuan Yongqiang
Keyword(s):  
Steam Turbine ◽  
Peak Load ◽  
Electricity Consumption ◽  
Control Valve ◽  
Clean Energy ◽  
Steam Pressure ◽  
Bypass Valve ◽  
Partial Load ◽  
Main Steam ◽  
Load Conditions

With the implementation of low-carbon economy policy, clean energy (such as wind and solar energy) has been developing rapidly, and the percentage is increasing year by year; On the other hand, with a steadily growing percentage of residential electricity consumption and commercial electricity consumption, resulting in large electricity load difference between peak and valley, the load related requirements of modern steam power plants are noticeably changing. Whereas the past units being designed in base load now have to take part in peak load, and usually in a low load operation, unable to play its advantages of high efficiency in design load. In the article the current three main governing methods (i.e. nozzle governing, throttling governing and bypass governing) for steam turbine will be discussed and evaluated under economical criteria focused on the above described challenges for future power generating technologies. A new governing method is Nozzle governing with Overload Valve Regulation, which keeps the advantage that main steam pressure of the Nozzle governing steam turbine is higher under partial load conditions, and weakens the influence of the low efficiency of governing stage on high pressure turbine, effectively improves the efficiency of steam turbine unit under partial load conditions. In the turbine adopted the new governing method of Nozzle governing with Overload Valve Regulation, the first stage is governing stage, divided into several groups. Main steam from boiler goes through the main stop valve and main steam control valve in sequence, and then turns to the governing stage. When the load is below 85%THA, main steam control valve I, II and III are fully opened, main steam control valve IV is fully closed, and the unit is in sliding pressure operation. When the load is 85%THA, the main steam pressure can reach the rated pressure. With the load increasing, main steam control valve IV starts to open, but the main steam pressure maintains the rated pressure, adjusted to THA when main steam control valve IV is fully opened and the flowrate of governing stage reaches the maximum. In the load more than THA condition, the bypass valve starts to open, the main steam goes through the bypass steam room into the certain stage (as fourth), to meet the requirements of the super load, adjusted to VWO (about 108%THA) when the bypass valve is fully opened. Through the detailed description about the scheme set and calculation analysis about economy benefit of the new regulation technology of Nozzle governing with Overload Valve Regulation, it shows that with the annual load range of 40%THA–85%THA, the economy of turbine adopted the new regulation technology is better than bypass governing by about 21.6 kJ/kW.h. (CSPE)

The Analysis of UHV Transmission’s Impact on Steam Turbine Operation

2017 ◽  
Author(s):  
Jin-long Liao ◽  
Zhi-hao Luo ◽  
Feng Yin ◽  
Bo Chen ◽  
Zi-tao Yu ◽  
...  
Keyword(s):  
Steam Turbine ◽  
High Voltage ◽  
Frequency Control ◽  
Control Valve ◽  
The Internet ◽  
Feed Water ◽  
Operating Personnel ◽  
Low Load ◽  
Primary Frequency ◽  
Ultra High Voltage

The Ultra-high Voltage (UHV) transmission has become an important developing direction of the Internet of Energy. Aiming at the influence of the Ultra-high Voltage transmission on the steam turbine, the primary frequency control (PFC) and low-load operation of units are analyzed emphatically. A coordination principle is proposed to guide operating personnel to modify PFC parameters. First, the PFC parameters are calculated qualitatively based on the proposed principle according to the units of Zhejiang province-China. Second, as the important embodiment of the PFC ability, the PFC capacity of a unit is illustrated from the angle of control valve opening, condensate throttling and feed water bypass and the removing high-pressure heater. Third, several measures are put forward to help increase the economical efficiency and safety when units are working in low-load due to the access of UHV. Finally, the future developing directions and the problems which need to be solved are discussed. The research of the effect of the UHV transmission on the steam turbine has great significance for the application of UHV and the Internet of energy (CSPE).

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