A Precise Full-Dimensional Design System for Multistage Steam Turbines: Part II — Key Technologies for Blade and Non-Blade Components, Engineering Application and Updating

Author(s):  
Xinzhong Xu ◽  
Kepeng Xu ◽  
Baoqing Li ◽  
Qing Chen ◽  
Hongde Jiang

In this part of present paper the key technologies for steam turbine blade and non-blade components developed by using the precise, full-dimensional (PFD) system is described firstly. For blade components advanced aerodynamic concept and design method for customized after-loaded profile, compound-lean blade, tandem cascade, contoured endwall, and solid particle erosion protection for HP and IP first nozzle have been developed. For non-blade component including main steam inlet/control valve, LP exhaust hood, packing seal and cavity flow, casing opening and condenser, new aerodynamic and mechanical design has been developed. New blade and non-blade components were experimentally and numerically investigated to verify its performance. Finite element method (FEM) analysis for all key components is also illustrated in this paper. Secondly the approach of validation and updating for the PFD system is introduced. Based on a large amount of on-site performance test data in power plants the statistic accuracy for the PFD system is given. It shows that in comparison with conventional F3D design methodology another 1.5-2 percent of HP and IP overall section efficiency improvement has been achieved.

1999 ◽  
Author(s):  
Alejandro Zaleta-Aguilar ◽  
Armando Gallegos-Muñoz ◽  
Antonio Valero ◽  
Javier Royo

Abstract This work builds on the previous work on “Exergoeconomics Fuel-Impact” developed by Torres (1991), Valero et. al. (1994), and compares it with respect to the Performance Test Code (PTC’s) actually applied in power plants (ASME/ANSI PTC-6, 1970). With the objective of proposing procedures for PTC’s in power plant’s based on an exergoeconomics point of view. It was necessary to validate the Fuel-Impact Theories, and improve the conceptual expression, in order to make it more applicable to the real conditions in the plant. By mean of a program using simulation and field data, it was possible to validate and compare the procedures. This work has analyzed an example of a 110 MW Power Plant, in which all the exergetic costs have been determined for the steam cycle, and a fuel-impact analysis has been developed for the steam turbines at the design and off-design conditions. The result of the fuel-impact analysis is compared with respect to a classical procedure related in ASME-PTC-6.


Author(s):  
Hongde Jiang ◽  
Kepeng Xu ◽  
Baoqing Li ◽  
Xinzhong Xu ◽  
Qing Chen

A new, precise full-dimensional (PFD) design system for multistage steam turbine has been developed in the past decades by the present authors. The remarkable features of PFD system different from conventional 3D design methodology are as followings: a). Taking into account of unsteady aerodynamic impact on steam turbine performance, b). Simulating 3D real structure of blade and non-blade components without geometric simplification, c). Coupling of aerodynamic design with FEM structure- mechanical analysis for blade and non-blade components. Three levels of design and optimization at global, regional and local level for steam turbine cycle and flow path design are described. The PFD design system consists of conceptual (0D), 1D, Q3D, F3D/4D aerodynamic design and optimization codes, structure analysis and mechanical design (MD) tools, and pre- and post-processing software. In this part of present paper a detail description of philosophy and architecture of the PFD design system, function of each design tools, principles for design consistency are given. The PFD design system is a new plateau of present author’s long-term effort to bring multistage steam turbine design from a simple, passive, empirical-based situation toward a comprehensive, active, knowledge-based environment.


2010 ◽  
Vol 139-141 ◽  
pp. 1277-1280
Author(s):  
Dong Hai Su ◽  
Mei Yan Zhang ◽  
Tie Qiang Ma ◽  
Xiao Qiu Han ◽  
Chuan Zong Sun ◽  
...  

In order to solve the engineering application problems of parametric rapidly in design of wind turbine tower, an automatic design method of wind turbine tower is put forward first, and the automatic design model was built through analyzing the key parameters and parameters’ calculation relation in different cases: same taper tower design and variable taper tower design. The key parameters, height, diameter and wall thickness of the tower, are mainly considered. Then, an automatic design system of the wind turbine tower is developed and realized according to the model. Finally, the system effectiveness is verified through taking a wind turbine for example. The results show that the system can enhance the design efficiency and shorten the cycle times at the same time.


Author(s):  
Christian Windemuth ◽  
Martin Lange ◽  
Ronald Mailach

Abstract Steam turbines are among the most important systems in commercial and industrial power conversion. As the amount of renewable energies increases, power plants formerly operated at steady state base load are now experiencing increased times at part load conditions. Besides other methods, the use of control valves is a widely spread method for controlling the power output of a steam turbine. In difference to other throttling approaches, the control valve enables fast load gradients as the boiler can be operated at constant conditions and allows a quicker response on variable power requirements. At part load, a significant amount of energy is dissipated across the valve, as the total inlet pressure of the turbine is decreased across the valve. At these conditions, the flow through the valve becomes trans- and supersonic and large pressure fluctuations appear within the downstream part of the valve. As a result, unsteady forces are acting on the valve structure and vibrations can be triggered, leading to mechanical stresses and possible failures of the valve. Besides more complex valve geometries, a spherical valve shape is still often used in smaller and industrial steam turbines. Because of the smooth head contour, the flow is prone to remain attached to the head surface and interact with the flow coming from the opposite side. This behaviour is accompanied by flow instabilities and large pressure fluctuations, leading to unsteady forces and possible couplings with mechanical frequencies. The spherical valve shape was therefore chosen as the experimental test geometry for the investigation of the unsteady flow field and fluid-structure-interactions within a scaled steam turbine control valve. Using numerical methods, the test valve is investigated and the time dependent pressure distribution in the downstream diffuser is evaluated. The evolution of the flow stability will be discussed for different pressure ratios. Pressure signals retrieved from the control valve test rig will be used to compare the numerical results to experimental data.


Author(s):  
Yiping Fu ◽  
Thomas Winterberger

Steam turbines for modern fossil and combined cycle power plants typically utilize a reheat cycle with High Pressure (HP), Intermediate Pressure (IP), and Low Pressure (LP) turbine sections. For an HP turbine section operating entirely in the superheat region, section efficiency can be calculated based on pressure and temperature measurements at the inlet and exhaust. For this case HP section efficiency is normally assumed to be a constant value over a load range if inlet control valve position and section pressure ratio remain constant. It has been observed that changes in inlet steam temperature impact HP section efficiency. K.C. Cotton stated that ‘the effect of throttle temperature on HP turbine efficiency is significant’ in his book ‘Evaluating and Improving Steam Turbine Performance’ (2nd Edition, 1998). The information and conclusions provided by K.C. Cotton are based on test results for large fossil units calculated with 1967 ASME steam tables. Since the time of Mr. Cotton’s observations, turbine configurations have evolved, more accurate 1997 ASME steam tables have been released, and our ability to quickly analyze large quantities of data has greatly increased. This paper studies the relationship between inlet steam temperature and HP section efficiency based on both 1967 and 1997 ASME steam tables and recent test data, which is analyzed computationally to reveal patterns and trends. With the efficiencies of various inlet pressure class HP section turbines being calculated with both 1967 and 1997 ASME steam tables, a comparison reveals different characteristics in the relationship between inlet steam temperature and HP section efficiency. Recommendations are made on how the results may be used to improve accuracy when testing and trending HP section performance.


Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 513
Author(s):  
Kexue Zhang ◽  
Lei Kang ◽  
Xuexi Chen ◽  
Manchao He ◽  
Chun Zhu ◽  
...  

Intelligent unmanned mining is a key process in coal mine production, which has direct impact on the production safety, coal output, economic benefits and social benefits of coal mine enterprises. With the rapid development and popularization of 5G+ intelligent mines and coal mine intelligent equipment in China, the intelligentization of intelligent unmanned mining has become an important research topic. Especially with the promulgation of some Chinese policies and regulations, intelligent unmanned mining technology has become one of the key technologies of coal mine production. To understand the connotation, status quo and development trends of intelligent unmanned mining, this paper takes the relationship between key technologies and engineering application of intelligent unmanned mining in China as the perspective. It is proposed that the intelligent unmanned mining technology is in the whole process of working face mining. A research structure of unmanned follow-up operation and safe patrol is changing to the mode of intelligent adaptive mining, followed by the basic concepts and characteristics of intelligent unmanned mining. Relevant researches that maybe beneficial to the proposed research content are reviewed in four layers, which include basic theory, key technology, mining mode, and overall design system theory and technology. Finally, the current intelligent unmanned mining mode and future trends in this field in China are summarized.


2014 ◽  
Vol 672-674 ◽  
pp. 1574-1579
Author(s):  
Jian Guo Jin ◽  
Wan Ting Cui ◽  
Jing Wen Yu

The relative internal efficiency for steam turbine is one of the main economic indexes in evaluating the economic operation of steam turbine. It is usually obtained by thermal performance tests or online monitoring. In power plants, by means of measuring and calculating the relative internal efficiency for steam turbine, steam turbines’ thermal economy can be analyzed and diagnosed, and the safe operation and energy saving work can be directed. But there still exist some problems in measuring and calculating the relative internal efficiency for steam turbine at present. In this paper, the two defining methods of the relative internal efficiency are analyzed and compared. The connection of two kinds of relative internal efficiency and the same effect in evaluating the operation economy of steam turbines are indicated.Key words : Steam Turbine; Thermal Performance Test; Economic Index ;Relative Internal Efficiency


Author(s):  
N. Lu¨ckemeyer ◽  
H. Almstedt ◽  
T.-U. Kern ◽  
H. Kirchner

There are no internationally recognized standards, such as the ASME Boiler and Pressure Vessel Code or European boiler and pipe codes, for the mechanical design of large steam turbine components in combined cycle power plants, steam power plants and nuclear power plants. One reason for this is that the mechanical design of steam turbines is very complex as the steam pressure is only one of many aspects which need to be taken into account. In more than one hundred years of steam turbine history the manufacturers have developed internal mechanical design philosophies based on both experience and research. As the design of steam turbines is pushed to its limits with greater lifetimes, efficiency improvements and higher operating flexibility requested by customers, the validity and accuracy of these design philosophies become more and more important. This paper describes an integral approach for the structural analysis of large steam turbines which combines external design codes, material tests, research on the material behavior in co-operation with universities and experience gained from the existing fleet to derive a substantiated design philosophy. The paper covers the main parameters that need to be taken into account such as pressure, rotational forces and thermal loads and displacements, and identifies the relevant failure mechanisms such as creep fatigue, ductile failure and creep fatigue crack growth. It describes the efforts taken to improve the accuracy for materials already used in power plants today and materials with possible future use such as advanced steels or nickel based alloys.


Author(s):  
Christian Windemuth ◽  
Martin Lange ◽  
Ronald Mailach

Abstract Steam turbines are among the most important systems in the conversion of thermal into electrical power. As the amount of renewable energies increases, existing power plants are experiencing increased times at part load conditions. To control the power output of a steam turbine, the use of control valves is a widely spread method, allowing fast load gradients and a quicker response on variable power requirements. At part load, a significant amount of energy is dissipated across the valve, as the total inlet pressure of the turbine is reduced. At these conditions, the flow across the valve becomes trans- and supersonic and large pressure fluctuations appear within the downstream part of the valve. As a result, unsteady forces can trigger strong vibrations, leading to mechanical stresses and possible valve failures. A spherical valve shape is still used in smaller industrial steam turbines, in which the flow is prone to show strong flow instabilities across a wide range of operating points. Because of these known instabilities, the spherical valve shape was chosen as the experimental test geometry and the evaluation of the unsteady flow and fluid-structure-interaction within the scaled steam turbine control valve. Using numerical methods, the test valve is investigated and the time dependent pressure distribution in the downstream diffuser is evaluated. The evolution of the flow stability will be discussed for different pressure ratios. Pressure signals retrieved from the control valve test rig will be used to compare the numerical results to experimental data.


2012 ◽  
Vol 591-593 ◽  
pp. 11-14
Author(s):  
Yuan Yuan Shao ◽  
Qing Liang Zeng ◽  
Guan Tao Xuan ◽  
Xian Xi Liu

As is known to all, new mechanical product design is always on the basis of the original product, so to better use the exiting design resource, a mechanical product variant design method is presented. The new method is based on SML and parameter CAD. According to different geological conditions of coal mine, different types of hydraulic support are needed to design. So as a typical kind of mechanical product, hydraulic support is given as an example to demonstrate the new variant design method. Finally with SOLIDWORKS as a specific application object, integrated with SQLServer2000 database, a hydraulic support variant design system is realized by Visual Basic program, which shortens the cycle of mechanical product development and reduces duplication mechanical design greatly.


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