Numerical Analysis of the Effect of Misaligned Guide Vanes on Improving S-Shaped Characteristics for a Pump-TurbineSource: Journal of Fluids Engineering:;2018:;volume( 140 ):;issue: 003::page 31102Author:Yexiang, Xiao
,
Wei, Zhu
,
Zhengwei, Wang
,
Jin, Zhang
,
Soo-Hwang, Ahn
,
Chongji, Zeng
,
Yongyao, Luo
DOI: 10.1115/1.4038077Publisher: The American Society of Mechanical Engineers (ASME)
Abstract: The S-shaped characteristic curves in pump-turbines complicate synchronization with the electrical grid and affect system safety. Misaligned guide vanes (MGVs) are one of the most effective solutions to avoid S-shaped characteristics. The internal flow mechanism with the MGV for improving S-shaped characteristics was studied by numerical analysis. Six operating conditions were modeled in the S-shaped region. Four guide vanes were arranged as the MGVs to qualitatively and quantitatively analyze the flow behavior. The internal flow was quite complex at the four operating points without the MGV; here, the attack angle and the flow behavior had no obvious difference at each vane. For the similar conditions with MGVs, attack angles and internal flow fields varied clearly at each vane, especially in the vaneless region and in the runner blade passages. For the same discharge rates, total openings, and rotating speeds, the internal flows were quite different between with and without the MGVs. The MGVs disrupt the high-speed circumferential water ring (appreciably faster compared to the main flow) in the vaneless region and maintain operation with higher unit speeds. Consequently, the unit speed is larger at the same unit discharge in the S-shaped region. Therefore, the MGV method can reduce S-shaped characteristics.
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contributor author | Yexiang, Xiao | |
contributor author | Wei, Zhu | |
contributor author | Zhengwei, Wang | |
contributor author | Jin, Zhang | |
contributor author | Soo-Hwang, Ahn | |
contributor author | Chongji, Zeng | |
contributor author | Yongyao, Luo | |
date accessioned | 2019-02-28T11:00:16Z | |
date available | 2019-02-28T11:00:16Z | |
date copyright | 10/24/2017 12:00:00 AM | |
date issued | 2018 | |
identifier issn | 0098-2202 | |
identifier other | fe_140_03_031102.pdf | |
identifier uri | http://yetl.yabesh.ir/yetl1/handle/yetl/4251623 | |
description abstract | The S-shaped characteristic curves in pump-turbines complicate synchronization with the electrical grid and affect system safety. Misaligned guide vanes (MGVs) are one of the most effective solutions to avoid S-shaped characteristics. The internal flow mechanism with the MGV for improving S-shaped characteristics was studied by numerical analysis. Six operating conditions were modeled in the S-shaped region. Four guide vanes were arranged as the MGVs to qualitatively and quantitatively analyze the flow behavior. The internal flow was quite complex at the four operating points without the MGV; here, the attack angle and the flow behavior had no obvious difference at each vane. For the similar conditions with MGVs, attack angles and internal flow fields varied clearly at each vane, especially in the vaneless region and in the runner blade passages. For the same discharge rates, total openings, and rotating speeds, the internal flows were quite different between with and without the MGVs. The MGVs disrupt the high-speed circumferential water ring (appreciably faster compared to the main flow) in the vaneless region and maintain operation with higher unit speeds. Consequently, the unit speed is larger at the same unit discharge in the S-shaped region. Therefore, the MGV method can reduce S-shaped characteristics. | |
publisher | The American Society of Mechanical Engineers (ASME) | |
title | Numerical Analysis of the Effect of Misaligned Guide Vanes on Improving S-Shaped Characteristics for a Pump-Turbine | |
type | Journal Paper | |
journal volume | 140 | |
journal issue | 3 | |
journal title | Journal of Fluids Engineering | |
identifier doi | 10.1115/1.4038077 | |
journal fristpage | 31102 | |
journal lastpage | 031102-10 | |
tree | Journal of Fluids Engineering:;2018:;volume( 140 ):;issue: 003 | |
contenttype | Fulltext |