抽水蓄能机组工况转换过程中无叶区压力特性

发布时间：2018-04-14 17:35

本文选题：蓄能机组 + 工况转换　；参考：《中国水利水电科学研究院学报》2017年05期

【摘要】：抽水蓄能机组无叶区压力脉动是机组及厂房振动的重要振源之一,尤其在工况转换过程中对厂房及机组振动起到决定性作用。考虑到工况转换过程属于典型的非稳态时变过程,本文采用时域混频幅值方法与时频分析中的短时傅里叶分析方法对抽水方向调相转抽水与发电方向调相转发电过程中无叶区压力信号进行了分析。研究结果表明:工况转换时无叶区水环吸收功率受球阀工作密封投退影响,工作密封退出后至顶盖排气阀关闭前时间段内吸入功率恒定,不受排气回水过程影响。工况转换时,因密封退出导致水环增厚,恶化了无叶区压力脉动情况。抽水方向调相至抽水工况转换与发电方向调相至发电工况转换时,无叶区压力脉动分别在转轮造压过程中和小负荷区达到最大值。工况转换过程中,无叶区存在明显的动静干涉频率和一倍叶片过流频率。一倍叶片过流频率均起源于球阀密封退出瞬间,抽水方向调相转抽水时动静干涉频率起源于尾水与转轮接触时,而发电方向调相转发电时动静干涉频率与一倍叶片过流频率同时产生。
[Abstract]:The pressure pulsation in impeller zone of pumped storage unit is one of the important vibration sources of unit and powerhouse, especially in the process of changing working conditions, it plays a decisive role in the vibration of power house and unit.Considering that the transition process is a typical unsteady-state time-varying process,In this paper, the time-domain mixing amplitude method and the short-time Fourier analysis method in time-frequency analysis are used to analyze the leafless pressure signals in the process of pumping direction phase modulation and generation direction phase modulation.The results show that the absorption power of the water ring in the leafless zone is affected by the ball valve working seal during the working condition transition, and the suction power is constant during the period from the working seal exit to the top cover exhaust valve closing, and is not affected by the exhaust backwater process.The pressure pulsation in the leafless area is aggravated by the thickening of the water ring due to the exit of the seal.When the pumping direction from phase modulation to pumping condition is changed and the generation direction from phase modulation to generation condition, the pressure pulsation in the leafless zone reaches the maximum value in the rotary wheel pressure generation process and in the small load area, respectively.In the process of operating transition, there are obvious static and static interference frequency and double blade overcurrent frequency in the leafless region.The over flow frequency of the double blade originates from the exit moment of the ball valve seal, and the frequency of the static and static interference when the pumping direction is adjusted and the pump is transferred to the pump originates from the contact between the tail water and the runner.However, the frequency of static and static interference and the frequency of double blade overcurrent are generated simultaneously when the direction of power generation is adjusted to generate electricity.
【作者单位】：中国水利水电科学研究院信息中心;国网新源控股有限公司技术中心;
【基金】：国家电网公司科技项目(52573016001G) 国家自然科学基金项目(51309258)
【分类号】：TV734;TV743

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