Investigation of a Steam Turbine with Leaned Blades by Through Flow Analysis and 3D CFD Simulation

Author(s):  
Xiaodong Wang ◽  
Shun Kang ◽  
Ke Yang
Author(s):  
Vaclav Slama ◽  
Lukas Mrozek ◽  
Ladislav Tajc ◽  
Marek Klimko ◽  
Pavel Zitek

Abstract The nuclear power plant also includes a secondary cycle, one of the main components of which is a steam turbine. This device processes the thermal and pressure energy of steam and converts it into mechanical energy. The heat from the reactor is conveied to the secondary cycle in the steam generator. Reliable and safe operation of the steam turbine, and thus of the entire block, is ensured by valves. Flow in a pair of control valves is considered, where the steam flows through the valve chamber past the first valve to the second valve. The experimentally determined flow characteristic of both valves is presented. Data of the distribution of pressures in selected places of these valves are presented. For the typical operating characteristics of a turbine, the course of the coefficient of total pressure distribution losses on the surface of the valves is evaluated. The pressure at the bottom of the cone is compared with the pressure on the wall of the diffuser throat. The energy loss in the valves is compared with the loss in a separate diffuser with varying degrees of expansion. There is also distinguished whether the flow is separated out of the diffuser walls or not.


2013 ◽  
Vol 55 (10) ◽  
pp. 743-747
Author(s):  
Branko Staniša ◽  
Lidija Ćurković ◽  
Zdravko Schauperl
Keyword(s):  

2013 ◽  
Vol 753-755 ◽  
pp. 2766-2769
Author(s):  
Quan Zhang ◽  
Zhi Jun Shuai ◽  
Pan Zhou ◽  
Wan You Li

In this paper the seat vibration acceleration response was reduced through flow passage modification of the centrifugal pump which could decrease the fluid excitation of the pump. CFD simulation technology was applied to optimize the fluid field of the multi-stage centrifugal pump, and then the velocity, pressure fluctuation and fluid excitation were concerned to investigate the effect of optimization. Finally, the influence of fluid field modification on the seat vibration response was verified experimentally.


Author(s):  
Lars Moberg ◽  
Gianfranco Guidati ◽  
Sasha Savic

This paper focuses on (1) the basic compressor layout based on meridional through flow analysis and (2) the re-design of blades and vanes using sophisticated automated design optimization methods. All tools and processes are integrated into a consistent Compressor Design System, which runs on a powerful Linux cluster. This design system allows designing, analyzing and documenting blade design in mostly automated way. This frees the engineer from repetitive tasks and allows him to concentrate on a physical understanding and improvement of the compressor. The tools and methods are illustrated on the basis of an actual ALSTOM compressor. The main objectives of this upgrade are a modest increase in mass flow and an efficiency improvement. The latter is to be achieved through the replacement of NACA blades by modern Controlled Diffusion Airfoils (CDA). Results are presented including a CFD analysis of the front stages of the baseline and upgrade compressor.


Author(s):  
Tadashi Tanuma ◽  
Yasuhiro Sasao ◽  
Satoru Yamamoto ◽  
Yoshiki Niizeki ◽  
Naoki Shibukawa ◽  
...  

The purpose of this paper is to present a numerical evaluation method for the aerodynamic design and development of high-efficiency exhaust diffusers in steam turbines, as well as to present the comparison between the numerical results and measured data in an actual real scale development steam turbine. This paper presents numerical investigation of three-dimensional wet steam flows in a down-flow-type exhaust diffuser that has non-uniform inlet flows from a typical last turbine stage. This stage has long transonic blades designed using recent aerodynamic and mechanical design technologies, including superimposed leakages and blade wakes from several upstream low pressure turbine stages. The present numerical flow analysis showed detail three-dimensional flow structures considering circumferential flow distributions caused by the down-flow exhaust hood geometry and the swirl velocity component from the last stage blades, including flow separations in the exhaust diffuser. The results were compared with experimental data measured in an actual development steam turbine. Consequently, the proposed aerodynamic evaluation method was proved to be sufficiently accurate for steam turbine exhaust diffuser aerodynamic designs.


Author(s):  
J M O'Brien ◽  
P K Bansal

Steam turbine cogeneration analysis (STuCA) is a quasi-static cogeneration plant model that has been developed to simulate steam turbine cogeneration plants subject to varying loads. STuCA was developed to provide potential cogeneration plant users with a model that could simulate part-load performance over the expected operating range of the cogeneration plant using fundamental engineering analysis methods. The model was designed to bridge the gap between static design-point models that could not accommodate part-load conditions and complex part-load models which are too expensive for small scale cogeneration proposals. In addition, the model contains economic analysis tools to analyse the thermoeconomic performance of the plant and to conduct a cash flow analysis. These features are an extension to the static and part-load models. The model consists of four submodels: a load, system, plant and economic model. The load submodel drives the cogeneration plant simulation, supplying utility demands to the system models. The system submodels calculate the steam required by the system components to meet the utility demands. The plant submodel then predicts turbine and boiler performance as they meet the steam demand. The primary plant submodel outputs are the electricity generated and quantity of coal consumed by the boiler, which are used by the economic submodel to conduct a thermoeconomic analysis of the site as well as a discounted cash flow analysis. This method of modelling results in a model that can predict plant performance with respect to varying load and then use those data to conduct a meaningful economic performance analysis of the site.


Author(s):  
Milan V. Petrovic ◽  
George S. Dulikravich ◽  
Thomas J. Martin

By matching a well established fast through-flow analysis code and an efficient optimization algorithm, a new design system has been developed which optimizes hub and shroud geometry and inlet and exit flow-field parameters for each blade row of a multistage axial flow turbine. The compressible steady state inviscid through-flow code with high fidelity loss and mixing models, based on stream function method and finite element solution procedure, is suitable for fast and accurate flow calculation and performance prediction of multistage axial flow turbines at design and significant off-design conditions. A general-purpose hybrid constrained optimization package has been developed that includes the following modules: genetic algorithm, simulated annealing, modified Nelder-Mead method, sequential quadratic programming, and Davidon-Fletcher-Powell gradient search algorithm. The optimizer performs automatic switching among the modules each time when the local minimum is detected thus offering a robust and versatile tool for constrained multidisciplinary optimization. An analysis of the loss correlations was made to find parameters that have influence on the turbine performance. By varying seventeen variables per each turbine stage it is possible to find an optimal radial distribution of flow parameters at the inlet and outlet of every blade row. Simultaneously, an optimized meridional flow path is found that is defined by the optimized shape of the hub and shroud. The design system has been demonstrated using an example of a single stage transonic axial gas turbine, although the method is directly applicable to multistage turbine optimization. The comparison of computed performance of initial and optimized design shows significant improvement in the turbine efficiency at design and off-design conditions. The entire design optimization process is feasible on a typical single-processor workstation.


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