摘要
为进一步揭示气液两相条件下泵反转作液力透平的流动特性,考虑相间拖曳力和虚拟质量力,以空气和水作为能量回收工质,基于Euler-Euler非均相流模型,在泡状流型入流的假定条件下,对入口含气率分别为5%、15%、25%、40%的液力透平内流场进行了定常数值计算。结果表明:随着入口含气率的增加,相同流量下液力透平的水力效率和输出功率降低而压头升高,最高效率时对应的流量发生偏移;相同入口含气率下,沿蜗壳流道截面气相浓度和气相分布均匀度均降低,气相聚集于蜗壳截面中下方;不同入口含气率和流量下,各过流部件中蜗壳内气相分布相对最均匀;随入口含气率和流量的升高,各过流部件的气相浓度和分布的不均匀度均增加,存在明显的分界;叶轮流道内气相聚向叶片吸力面,随着入口含气率和流量的增加气相聚集程度增强、范围扩大,气相聚并成气团而滞留于叶轮流道,产生相态分离,气团上游存在对应漩涡;入口含气率较低时叶片压力面气相主要聚集在高压边侧,随着入口含气率增加,气相在叶片表面扩散,叶片压力面高压边附近靠近前盖板侧区域的气相浓度较高,叶片吸力面低压边附近区域的气相浓度较高;透平内气相速度总体上大于液相速度。
For purpose of further revealing the flow characteristics while taking a pump as turbine(PAT)at gas-liquid condition,through considering drag force and virtual mass force and taking air and water as the medium,as well as basing on Euler-Euler inhomogeneous model and the assumption of bubbly inflow,the steady numerical calculation of internal flow field of the PAT with the inlet gas volume fraction(IGVF)staying at 5%,15%,25%and 40%respectively was carried out.The results showed that,with the increase of IGVF,both efficiency and output power of the PAT decreases while pressure head increases at the same flow rate,and corresponding flow rate at the highest efficiency deviates;at the same IGVF,both gas concentration and uniformity of the gas distribution along volute channel are reduced,and the gas gathers at the bottom of volute section;the gas distribution in the volute is the most uniform relatively among flow passage parts of the PAT at the different IGVF and flow rate;the non uniformity of gas concentration and distribution increases with the increase of the IGVF and flow rate,and there are clear boundaries;the gas in the impeller gathers on suction surface of the blade,and both degree and range of accumulation increase with the increase of the IGVF and flow rate,and the gas gathers into air mass and stays in the impeller passage,the phase separation occurs and there are corresponding vortices in the upstream near the air masses;the gas on pressure surface of the blade is mainly concentrated on the high pressure side when the IGVF is low,the gas diffuses on the blade surface,and the gas concentration near the blade pressure surface’s high pressure side close to the shroud is relatively higher while the gas concentration near the blade suction surface’s low pressure side is higher.The gas velocity in the PAT is larger than the liquid’s generally.
作者
毕智高
刘甜甜
谢勰
相玉琳
王金玺
BI Zhi-gao;LIU Tian-tian;XIE Xie;XIANG Yu-lin;WANG Jin-xi(School of Chemistry and Chemical Engineering,Yulin University;Shaanxi Key Laboratory of Low Metamorphic Coal Clean Utilization;Planning Department,PetroChina Changqing Oilfield Company)
出处
《化工机械》
CAS
2021年第1期76-83,共8页
Chemical Engineering & Machinery
基金
国家自然科学基金项目(41967022)
陕西省教育厅重点实验室项目(18JS122)。
