Influences of runner blade shape on the transient behaviours of pump-turbines in load rejection

Xia, Linsheng; Zhang, Chun-Ze; Hu, Li

doi:10.1080/00221686.2020.1780503

Cited by 7 publications

(4 citation statements)

References 31 publications

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“…The SAS modifications to the standard k-ω SST turbulence model allow for a decrease in the turbulent viscosity where the turbulence may be partially or fully resolved [25]. This turbulence model has recently been successfully used in a number of studies concerning transient operations in a hydropower context [14,15,26]. The simulations were carried out on the full 3D computational domain shown in Figure 1b.…”

Section: Governing Equations and Numerical Schemesmentioning

confidence: 99%

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Flow Characteristics of Preliminary Shutdown and Startup Sequences for a Model Counter-Rotating Pump-Turbine

2021

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Pumped Hydropower Storage (PHS) is the maturest and most economically viable technology for storing energy and regulating the electrical grid on a large scale. Due to the growing amount of intermittent renewable energy sources, the necessity of maintaining grid stability increases. Most PHS facilities today require a geographical topology with large differences in elevation. The ALPHEUS H2020 EU project has the aim to develop PHS for flat geographical topologies. The present study was concerned with the initial design of a low-head model counter-rotating pump-turbine. The machine was numerically analysed during the shutdown and startup sequences using computational fluid dynamics. The rotational speed of the individual runners was decreased from the design point to stand-still and increased back to the design point, in both pump and turbine modes. As the rotational speeds were close to zero, the flow field was chaotic, and a large flow separation occurred by the blades of the runners. Rapid load variations on the runner blades and reverse flow were encountered in pump mode as the machine lost the ability to produce head. The loads were less severe in the turbine mode sequence. Frequency analyses revealed that the blade passing frequencies and their linear combinations yielded the strongest pulsations in the system.

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Section: Governing Equations and Numerical Schemesmentioning

confidence: 99%

“…Recent studies of Francis-like pump-turbines have shown that it is possible to numerically predict the flow characteristics during transient sequences such as load-rejection and mode-switching [14][15][16][17]. The current study investigated the shutdown and startup sequences for a model-scale CRPT, in both pump and turbine modes.…”

Section: Introductionmentioning

confidence: 99%

Flow Characteristics of Preliminary Shutdown and Startup Sequences for a Model Counter-Rotating Pump-Turbine

2021

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“…It should be noted that both two unsteady characteristics are strongly related to the flow characteristic in vaneless region. High pressure side, as the runner outlet at pump mode and runner inlet at turbine mode, playing an important role in controlling these two unsteady characteristics [6,7]. While only few published papers investigate the relationship between hump characteristic and S characteristic, not to mention the relationship between efficiency at design points and margin of unsteady characteristics.…”

Section: Introductionmentioning

confidence: 99%

Parametric design and multi-objective optimization on blade high-pressure side of a pump-turbine

Qin

Wang

et al. 2022

IOP Conf. Ser.: Earth Environ. Sci.

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High pressure side, as the runner outlet at pump mode and runner inlet at turbine mode, playing an important role in controlling hydraulic loss and flow characteristics in vaneless region, affecting both steady characteristics and unsteady characteristics. While when it comes to three-dimensional inverse design of a pump-turbine blade, scholars are forces on the design method in runner flow channel, ignoring the geometry profile of high-pressure side. Hence, in present paper, concepts “swept”, “bowed (lean)” and “twisted” are innovatively introduced, eight new parameters are proposed to control the profile of blade high pressure side. And then a multi-objective optimization design system consisting of geometry generation, computational fluid dynamics, design of experiment, approximation model, multi-objective genetic algorithm, and self-organization map is built. Efficiency at both pump mode and turbine mode and S margin at turbine mode are selected as optimization objectives in the first optimization step. Then, the hump margin is regard as the objective in the second optimization step. Based on the two-step optimization, a runner with optimized high-pressure side is obtained and CFD results show that compared with the original runner, the efficiency at rated points and the margin of unsteady characteristics can be increased. The parametric design method on high-pressure side presented in our paper can be regard as an essential supplement to the traditional design method in hydraulic machinery.

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“…Düşük irtifalı rezervden yüksek irtifalı rezerve su basan tesislere pompaj depolamalı hidroelektrik santrali denmektedir. Bu tür tesislerin amacı, rüzgâr, güneş ve dalga gibi geçici kaynaklardan elde edilen elektrik enerjinin elektrik şebekesine verildiği zamanlarda veya elektrik enerjisine olan ihtiyacın azaldığı zamanlarda (mesela gece) düşük irtifalı bir rezervdeki suyu yüksek irtifalı bir rezerve pompalayarak enerji depolaması yapmaktır [32][33][34][35].…”

Section: Giriş (Introduction)unclassified

Radyal akışlı francis su türbinlerinin kanatçık profilinin belirlenmesi ve performans analizi için bir matematik modelin geliştirilmesi

Özdemir

Karabulut

2022

Gazi Üniversitesi Mühendislik Mimarlık Fakültesi Dergisi

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Turbo makinelerin rotor kanatçıklarının tasarımında Euler’in turbo makinelerin moment ve güç hesabı için türettiği eşitlik kullanılmaktadır. Bu eşitlik ile sadece rotor kanatçıklarının giriş ve çıkış açıları belirlenebilmekte, kanatçıkların tam profili belirlenememektedir. Kanatçıkların arasındaki rölatif akışın yerel hız ve yerel ivmesinin belirlenmesi için kanatçıkların tam profilinin bilinmesi gerekmektedir. Bu çalışmada, içten dışa radyal akışlı su türbini çarkının momentini belirlemede kullanılmak üzere bir matematik model geliştirilmiştir. Geliştirilen modelde türbin kanatçıklarının profili silindirik koordinat sistemine göre matematiksel olarak tanımlanmakta ve kanatçıklar arasından geçmekte olan akışkan zerrelerinin yerel hız ve ivme dağılımları hesaplanmaktadır. Hesaplanan hız dağılımı kanatçıkların giriş ve çıkışındaki hız üçgenlerinin oluşturulmasına ve Euler türbin teorisi yardımı ile çarka etkiyen harici moment ve gücün hesaplanmasına imkân vermektedir. Ayrıca, geliştirilen model kullanılarak, çark üzerinde oluşturulan hacim elemanlarına etkiyen atalet kuvvetleri ve bu kuvvetlerin çark eksenine göre oluşturduğu momentler tanımlanmakta, sonra integral hesap ile çarka etkiyen toplam moment ve güç hesaplanmaktadır. İntegral hesaptan elde edilen moment bağıntısı sürekli çalışma şartlarında Euler türbin teorisinden elde edilen moment bağıntısına dönüşmektedir. Geliştirilen moment denklemi kullanılarak 10 m3/s civarında debiye ve 100-200 m aralığında düşüye sahip olan bir su kaynağı için türbin çarkının analizleri yapılmıştır. Kanatçık profilinin ivme ve dolayısıyla çarkın performansı üzerinde etkili olduğu tesit edilmiştir.

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Influences of runner blade shape on the transient behaviours of pump-turbines in load rejection

Cited by 7 publications

References 31 publications

Flow Characteristics of Preliminary Shutdown and Startup Sequences for a Model Counter-Rotating Pump-Turbine

Flow Characteristics of Preliminary Shutdown and Startup Sequences for a Model Counter-Rotating Pump-Turbine

Parametric design and multi-objective optimization on blade high-pressure side of a pump-turbine

Radyal akışlı francis su türbinlerinin kanatçık profilinin belirlenmesi ve performans analizi için bir matematik modelin geliştirilmesi

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