付婧,张飞.抽水蓄能机组工况转换过程中无叶区压力特性[J].中国水利水电科学研究院学报,2017,(5):376-381
抽水蓄能机组工况转换过程中无叶区压力特性
Vaneless zone pressure characteristics in working mode transferring process of pumped-storage unit
投稿时间:2017-05-18  
DOI:10.13244/j.cnki.jiwhr.2017.05.008
中文关键词:  蓄能机组  工况转换  水环  短时傅里叶变换  叶片过流频率  动静干涉
英文关键词:pumped-storage unit  working mode transferring  water ring  short-time-Fourier transform  blade passing frequency  rotor-stator interaction
基金项目:国家电网公司科技项目(52573016001G);国家自然科学基金项目(51309258)
作者单位E-mail
付婧 中国水利水电科学研究院 信息中心, 北京 100048  
张飞 国网新源控股有限公司技术中心, 北京 100161 spiritgiant@126.com 
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中文摘要:
      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。
英文摘要:
      Vaneless zone pressure pulsation is the main vibration source of pump-storage powerhouse and unit, especially in the working mode transferring processes. Considering that the working mode transferring processes are typical non-stable processes,peak-to-peak value analysis in time domain and short-time-Fou-rier transform in time-frequency domain have been employed for analyzing the vaneless zone pressure in the processes of synchronous condenser pump (SCP) to pumping operation (PO) and synchronous condens-er turbine (SCT) to generating operation (GO). The research indicates that water ring absorption power is heavily influenced by working seal operation,and the power absorption,which is not influenced by the pro-cess of air-evacuation-water-recover, keeps constant from the time working seal withdrawing to the time air evacuation value closing in working mode transferring processes. Once the water ring thickness increases after the seal withdrawing, the vaneless zone pressure pulsation aggravates. During SCP to PO and SCT to PO, the maximum vaneless pressure peak-to-peak values occurs in the period of runner chamber pressure establishment and the low load operation zone respectively. During the working mode transferring processes, blade passing frequency and rotor-stator interaction frequency arise apparently. Blade passing frequency emerges on the time seal withdrawing; for SCP to PO, the rotor-stator interaction frequency emerges on the time runner contacting draft-tube water, while for SCT to GO, the rotor-stator interaction frequency emerges simultaneously with blade passing frequency.
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