spiral case
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Author(s):  
Dinesh Kanvagiya

Abstract: Generating more Power are complex at cheaper cost, also continuous energy supplied are important Hydro power generation is one of the most successful renewable energy resources for the production electrical energy without any environmental hazard and presently it providing more than 86% of all electricity generated by renewable sources worldwide and accounts for about 20% of world electricity. To increase the percentage of green energy in account of world electricity generation the analysis must be performed to get the information about the working conditions of each component in plants so that the required maintenance action should be taken. Maintenance and operation of a hydro power plant is very complicated and the process to calculate and analyzing its compatibility and reliability is very important. In this work introducing a Markov model to evaluate the reliability parameter of THPS-I Sirmour, Rewa. For this work the operational data regarding failure and maintenance time taken to repaired and analysis of all parts of generating unit of the power plant for period of 2010-2015 is considered. The availability and reliability of individual unit of power plant is evaluated by taking into account different reliability Parameters, namely failure rate (λ), repair rate (µ), MTTR, MTTF, MTBF through the collected data and tabulating the required information for the analysis. By this analysis work we can improve reliability of all the components of each unit of power plant. The sub-unit that is commonly failed during operation is like- penstock, butter fly valve, spiral case, turbine, generator, excitation system, speed governor etc. Reliability plays a key role in the cost-effectiveness of systems Keywords: Hydro power plant, Reliability evaluation, Reliability parameters, Markov analysis, Total schedule outage hrs and Total forced outage hrs.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Tomas Ivan Träskman ◽  
Matti Skoog

PurposeThe present study aims to address the emergence of platform-organized open innovation (OI). The research has the two main aims: the first is to increase the understanding of the performance of OI by investigating how the achievements of OI are measured in situated practices from a performative and strategic knowledge management (SKM) orientation. The methodological disadvantages of not pre-given case selection are partially counterbalanced by the second aim of the research, which is to extend existing SKM theory and examine how platforms create knowledge as they include actors and digital devices, thereby potentially redistributing relations of accountability.Design/methodology/approachBuilding on performativity theory, the paper studies how the achievements and knowledge created in OI are managed and evaluated in practice. The case description draws on different sources from a spiral case study, as openness is performed by platform, firm, crowd and innovation intermediaries.FindingsThe paper illustrates how a strategy of digitally enabled openness brings its own issues as platforms enable knowledge sharing and perform a redistribution of accountability. In the heterarchies studied through this research endeavor, managers and their team members were accountable not only to multiple units, or teams, across the organization, but also to the crowd. The case material demonstrates that the ecology of devices and their performative struggles create lateral accountability.Research limitations/implicationsWhile recent streams of research suggest that the context of OI (i.e. distributed sources of knowledge for innovation) shifts the unit of analysis of organization design from the individual firm to networks of actors organized on platforms, the authors find that the focal firm still remains a key conceptual parameter in SKM research, which, in turn, makes it difficult to capture the suggested radicality of OI.Practical implicationsThe authors show, that in practice, the firm has to take into account the performance of the external crowd and at times put resources into its training and education. In heterarchy, distributed authority is assumed to be facilitated through lateral accountability, whereby the traditional principles of vertical authority no longer hold, but rather, managers and their team members can be accountable to multiple units, or teams, across the organization.Originality/valueThe paper develops a performative theory of openness. OI is a model, strategy and socio-material practice whereby digital designs create an ecology of devices that can enact all kinds of openness. Ultimately, the current paper proposes that SKM and OI theory need to consider how platforms perform relations of accountability beyond the boundaries of the single organization.


2021 ◽  
Vol 320 ◽  
pp. 04005
Author(s):  
E. N. Dolmatov ◽  
S. Y. Ilin ◽  
V. V. Eliferov

During operation of Francis hydro turbines at the regimes of 70–95 % of Nrated, high-frequency acoustic phenomena (noise) were recorded. In order to study and identify the causes of these phenomena, special field tests were conducted. The main objectives of the tests were: determination of the main frequencies of acoustic phenomena, comparison with natural frequencies of the turbine water passages elements and the search for solutions to reduce acoustic phenomena. During the tests, the natural frequencies of the elements of turbine water path were investigated. Several methods of air injection to the turbine water path were also tested. The most effective way (including by the amount of air) to reduce acoustic phenomena was the air injection from industrial air piping into the spiral case and into the area of guide vanes.


2020 ◽  
Vol 18 (1) ◽  
pp. 126
Author(s):  
Chandra Buana ◽  
Jumadi Tangko ◽  
Andi Afdhal Rasydiman ◽  
Ahmad Tamal S
Keyword(s):  

Pembangkit listrik tenaga air merupakan pembangkit listrik yang memanfaatkan energi kinetik air yang memutar turbin yang telah dikopel dengan generator untuk menghasilkan listrik. Guide vane merupakan suatu komponen utama pada turbin air yang diberfungsi untuk mengarahkan air yang masuk pada spiral case agar air dapat memusatkan tekanan pada runner blade atau sudu turbin. Penelitian ini bertujuan untuk mengetahui sifat mekanis guide vane hasil pengecoran alumunium dan tembaga.Metode yang digunakan adalah uji kekerasan mekanis metode Brinnel (HB) menggunakan pengecoran alumunium dan tembaga dengan berbagai macam perbandingan spesimen yaitu 1:2, 1:1, 2:1. Nilai kekerasan untuk setiap spesimen akan meningkat seiring dengan bertambahnya kandungan tembaga didalam spesimen tersebut. Spesimen dengan perbandingan 1:2  tidak baik untuk digunakan dalam pembuatan guide vane karena memilki nilai kekerasan brinnel yang rendah dan tidak stabil pada setiap bagiannya. Spesimen dengan perbandingan 1:1 memiliki nilai kekerasan yang stabil di setiap bagiannya dan  baik untuk digunakan dalam pembuatan guide vane, selain itu biaya yang dibutuhkan lebih murah di bandingkan dengan spesimen 2:1 karena memiliki nilai kandungan tembaga yang lebih kecil dari spesimen 2:1.


2020 ◽  
Vol 16 (2) ◽  
pp. 35-46
Author(s):  
Nohyun Park ◽  
Jin-Hyuk Kim ◽  
Seung-Jun Kim ◽  
Jungjae Hyun ◽  
Jongwoong Choi ◽  
...  

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 1000 ◽  
Author(s):  
Jiawei Ye ◽  
Wei Zeng ◽  
Zhigao Zhao ◽  
Jiebin Yang ◽  
Jiandong Yang

In load rejection transitional processes in pumped-storage plants (PSPs), the process of closing pump turbines, including guide vane (GVCS) and ball valve closing schemes (BVCS), is crucial for controlling pulsating pressures and water hammer. Extreme pressures generated during the load rejection process may result in fatigue damage to turbines, and cracks or even bursts in the penstocks. In this study, the closing schemes for pump turbine guide vanes and ball valves are optimized to minimize water hammer and pulsating pressures. A model is first developed to simulate water hammer pressures and to estimate pulsating pressures at the spiral case and draft tube of a pump turbine. This is combined with genetic algorithms (GA) or non-dominated sorting genetic algorithm II (NSGA-II) to realize single- or multi-objective optimizations. To increase the applicability of the optimized result to different scenarios, the optimization model is further extended by considering two different load-rejection scenarios: full load-rejection of one pump versus two pump turbines, simultaneously. The fuzzy membership degree method provides the best compromise solution for the attained Pareto solutions set in the multi-objective optimization. Employing these optimization models, robust closing schemes can be developed for guide vanes and ball valves under various design requirements.


Author(s):  
Yongfeng Qi ◽  
Qin Chen ◽  
Yaqi Gong ◽  
Zhiqiang Xie

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