彭世亮,王卫良,吕俊复,柯希玮,刘志东,马庆中

• 1:暨南大学重大工程灾害与控制教育部重点实验室国际能源学院(能源电力研究中心)
• 2:清华大学热科学与动力工程教育部重点实验室
• 3:怀柔实验室山西研究院
• 4:广东珠海金湾发电有限公司

摘要(Abstract)：

构建以新能源为主体的新型电力系统，对燃煤发电机组深度调峰和超低负荷运行提出了越来越严苛的要求，进而对汽轮机组低负荷安全运行提出了越来越严峻的挑战。采用数值模拟方法，基于低负荷工况下汽轮机末级运行性能的深入分析，着重研究探索了不同解决方案在超低负荷工况下的工作机理与优化效果。研究发现，当机组从中低负荷下降到超低负荷时，末级叶片附近出现间隙涡、回流涡和分离涡等涡群，其范围随着负荷的减小逐渐扩大。低负荷工况降低机组背压和低压缸切缸运行是弱化汽轮机涡流、提高末级性能的有效途径，二者结合使用效果更佳。例如，在20%热耗率验收（THA）工况条件下，将背压从4.9 k Pa降低到2.5 k Pa，使得末级涡群影响范围明显减小，转子叶片转矩从–38 N·m增加到73N·m，末级运行性能明显改善。在10%THA工况下，采用降低背压和低压缸切缸相结合可使叶顶间隙涡完全消失，回流涡和分离涡的径向长度都减小50%以上；优化后的动叶转矩增加了约130 N·m，末级运行性能改善效果显著。

关键词(KeyWords)： 汽轮机;低负荷工况;涡流;背压;切缸

Abstract:

Keywords:

基金项目(Foundation): 珠海市产学研合作项目（2220004003010）;; “十四五”国家重点研发计划（2022YFB4100805）;; 中国华能集团有限公司总部科技项目“基础能源科技研究专项（三）（HNKJ22-H105）~~

作者(Author): 彭世亮,王卫良,吕俊复,柯希玮,刘志东,马庆中

DOI: 10.19666/j.rlfd.202401021

参考文献(References)：

• [1]BROUWER A S,VAN DEN BROEK M,SEEBREGTSA,et al.Operational flexibility and economics of power plants in future low-carbon power systems[J].Applied Energy,2015,156:107-128.
• [2]潘旭东,黄豫,唐金锐,等.新能源发电发展的影响因素分析及前景展望[J].智慧电力,2019,47(11):41-47.PAN Xudong,HUANG Yu,TANG Jinrui,et al.Analysis of influencing factors and prospects for development of new energy power generation[J].Smart Electricity,2019,47(11):41-47.
• [3]曹丽华,李禹,司和勇.超低负荷工况下大功率汽轮机低压缸内温度场分布特性研究[J].中国电机工程学报,2021,41(3):1018-1026.CAO Lihua,LI Yu,SI Heyong.Study on temperature field distribution characteristics in low pressure cylinder of high power turbine under ultra-low load condition[J].Proceedings of the CSEE,2021,41(3):1018-1026.
• [4]李勇,杨磊磊.汽轮机变工况各级热力参数计算方法研究[J].汽轮机技术,2015,57(5):321-325.LI Yong,YANG Leilei.Study on calculation method of thermal parameters of steam turbine under varying operating conditions[J].Steam Turbine Technology,2015,57(5):321-325.
• [5]张希富,王运民,师保平,等.电厂汽轮机组变负荷运行安全经济性分析[J].汽轮机技术,2014,56(6):464-466.ZHANG Xifu,WANG Yunmin,SHI Baoping,et al.Safety and economic analysis of variable load operation of turbine units in power plant[J].Turbine Technology,2014,56(6):464-466.
• [6]SZ J K,SEGURA J,GARCíA J,et al.Failure analysis of the 350 MW steam turbine blade root[J].Engineering Failure Analysis,2009,16(4):1270-1281.
• [7]AHMAD M,CASEY M,SüRKEN N.Experimental assessment of droplet impact erosion resistance of steam turbine blade materials[J].Wear,2009,267(9/10):1605-1618.
• [8]龚晨,李录平,张世海,等.国产600 MW汽轮机末级叶轮振动特性有限元分析[J].汽轮机技术,2016,58(6):439-443.GONG Chen,LI Luping,ZHANG Shihai,et al.Finite element analysis of vibration characteristics of final stage impeller of 600 MW steam turbine[J].Steam Turbine Technology,2016,58(6):439-443.
• [9]章巧芳,盛颂恩.汽轮机末级扭叶片振动特性分析[J].汽轮机技术,2005(4):273-274.ZHANG Qiaofang,SHENG Song’en.Vibration characteristics analysis of turbine final torsional blade[J].Turbine Technology,2005(4):273-274.
• [10]HU P,LIN T,YANG R,et al.Numerical investigation on flow instabilities in low-pressure steam turbine last stage under different low-load conditions[J].Proceedings of the Institution of Mechanical Engineers,Part A:Journal of Power and Energy,2021,235(6):1544-1562.
• [11]MAZUR Z,GARCIA-ILLESCAS R,AGUIRRE-ROMANO J,et al.Steam turbine blade failure analysis[J].Engineering Failure Analysis,2008,15(1/2):129-141.
• [12]宁哲,安敏善,孟凡林,等.空冷200 MW汽轮机末级流场试验研究[J].热力发电,1991,20(3):43-52.NING Zhe,AN Minshan,MENG Fanlin,et al.Experimental study on final stage flow Field of air-cooled 200 MW steam turbine[J].Thermal Power Generation,1991,20(3):43-52.
• [13]王仲博,宁哲,赵毅,等.200 MW干式冷却汽轮机末级流动特性试验研究[J].中国电力,1997(3):41-43.WANG Zhongbo,NING Zhe,ZHAO Yi,et al.Experimental study on final stage flow characteristics of200 MW dry-cooled steam turbine[J].Electric Power,1997(3):41-43.
• [14]金建国,李勇,曹丽华.小容积流量工况下汽轮机末级流场的计算研究[J].汽轮机技术,2004(6):411-414.JIN Jianguo,LI Yong,CAO Lihua.Study on calculation of final stage flow field of steam turbine under low volume flow condition[J].Steam Turbine Technology,2004(6):411-414.
• [15]GERSCHüTZ W,CASEY M,TRUCKENMüLLER F.Experimental investigations of rotating flow instabilities in the last stage of a low-pressure model steam turbine during windage[J].Proceedings of the Institution of Mechanical Engineers,Part A:Journal of Power and Energy,2005,219(6):499-510.
• [16]SEGAWA K,SENOO S,HAMATAKE H,et al.Steady and unsteady flow measurements under low load conditions in a low pressure model steam turbine[C].2012 20th International Conference on Nuclear Engineering and the ASME 2012 Power Conference,2012:833-839.
• [17]徐美超,曹丽华,赵金峰,等.小容积流量下汽轮机末级流场涡流特性研究[J].汽轮机技术,2019,61(5):321-325.XU Meichao,CAO Lihua,ZHAO Jinfeng,et al.Research on eddy current characteristics of turbine final stage flow field under small volume flow[J].Turbine Technology,2019,61(5):321-325.
• [18]石红晖,张攀,曹蓉秀,等.小流量条件下低压缸末级流动特性研究[J].动力工程学报,2022,42(2):109-114.SHI Honghui,ZHANG Pan,CAO Rongxiu,et al.Study on final stage flow characteristics of low pressure cylinder under low flow condition[J].Journal of Dynamic Engineering,2022,42(2):109-114.
• [19]?IVNYA,MACáLKA A,HOZNEDL M,et al.Numerical investigation and validation of the 1 090 MWsteam turbine exhaust hood flow field[C].ASME Turbo Expo 2017:Turbomachinery Technical Conference and Exposition,2017.
• [20]SIGG R,HEINZ C,CASEY M V,et al.Numerical and experimental investigation of a low-pressure steam turbine during windage[J].Proceedings of the Institution of Mechanical Engineers,Part A:Journal of Power and Energy,2009,223(6):697-708.
• [21]SUN T,PETRIE-REPAR P,VOGT D M,et al.Detached-eddy simulation applied to aeroelastic stability analysis in a last-stage steam turbine blade[J].Journal of Turbomachinery,2019,141(9):091002.1-091002.11.
• [22]ZHANG L Y,HE L,STüER H.3-D time domain unsteady computation of rotating instability in steam turbine last stage[C].ASME Turbo Expo 2012:Turbine Technical Conference and Exposition,2012:559-567.
• [23]GARG D K,CHAMBALWAR S,SARODE J,et al.Investigation of rotating instability in the last stage of low pressure turbine during low volume flow operation[J].International Journal of Recent advances in Mechanical Engineering,2015,4(2):29-37.
• [24]RAMA RAO A,DUTTA B K.Blade vibration triggered by low load and high back pressure[J].Engineering Failure Analysis,2014,46:40-48.
• [25]WANG Z,SHI H,CAO L,et al.Analysis on strength performance of the last stage blade in steam turbine under low mass flow conditions[J].Proceedings of the Institution of Mechanical Engineers,Part C:Journal of Mechanical Engineering Science,2022,236(13):7095-7106.
• [26]LI P,YUAN Q.Stress variation of a gas turbine tie-bolt rotor with Hirth serrations considering assembling and thermal effects[J].Proceedings of the Institution of Mechanical Engineers,Part C:Journal of Mechanical Engineering Science,2020,234(24):4932-4944.
• [27]PAN T,GONG T,YANG W,et al.Numerical study on the thermal stress and its formation mechanism of a thermoelectric device[J].Journal of Thermal Science,2018,27(3):249-258.
• [28]MENTER F R,KUNTZ M,LANGTRY R.Ten years of industrial experience with the SST turbulence model[J].Turbulence,Heat and Mass Transfer,2003,4(1):625-632.
• [29]BAKHTAR F,YOUNG J,WHITE A,et al.Classical nucleation theory and its application to condensing steam flow calculations[J].Proceedings of the Institution of Mechanical Engineers,Part C:Journal of Mechanical Engineering Science,2005,219(12):1315-1333.
• [30]YU X,XIAO Z,XIE D,et al.A 3D method to evaluate moisture losses in a low pressure steam turbine:application to a last stage[J].International Journal of Heat and Mass Transfer,2015,84:642-652.