超临界CO_(2)透平主流道及间隙流动特性分析  

Flow Characteristics Analysis of Main Flow Channel and Clearance of a Supercritical CO_(2) Turbine

作　　者：张磊 乔加飞 舒伟林 杨锐 杨国英 邓清华[3] 李军[3] ZHANG Lei;QIAO Jiafei;SHU Weilin;YANG Rui;YANG Guoying;DENG Qinghua;LI Jun(Guoneng Guohua(Beiing)Electric Power Research Institute Co.,Ltd.,Beijing 102209,China;Shanghai Turbine Works Co.,Ltd.,Shanghai 200240 China;School of Energy and Power Engineering,Xi'an Jiaotong University,Xi'an 710049,China)

机构地区：[1]国能国华(北京)电力研究院有限公司,北京102209 [2]上海汽轮机厂有限公司,上海200240 [3]西安交通大学能源与动力工程学院,西安710049

出　　处：《热力透平》2022年第3期184-190,共7页Thermal Turbine

摘　　要：以超临界CO_(2)为工质的闭式布雷顿循环系统具有结构紧凑、效率高等特征优势,符合可持续发展的需求。利用计算流体力学软件对某超临界CO_(2)轴流透平的气动性能和流动特性进行数值模拟,对比了主流道及考虑气封间隙后的流动特性差异。结果表明:超临界CO_(2)透平通流部分级等熵焓降和气流出口马赫数较低,不利于透平效率的提高;端壁二次流对于主流影响较大,末级出口的气流角仍有较大范围受端壁二次流影响;考虑气封间隙后,泄漏量占比非常大,第1级隔板气封处的泄漏量达到了总流量的7.4%,透平总静效率也下降了7.27%。该研究结果可为超临界CO_(2)机组的设计提供参考和借鉴。The closed Brayton cycle system with supercritical CO_(2)as working fluid has the advantages of compact structure,high efficiency,etc so as to meet continuous improvement.The aerodynamic performance and flow characteristics of a supercritical CO_(2)turbine with axial flow structure are numerically simulated using computational fluid dynamics software.And the differences of flow characteristics between the mainstream channel and the mainstream with seal clearance are compared.The results show that the stage isentropic enthalpy drop and Mach number at the outlet of supercritical carbon dioxide turbine are lower,which are not conductive to the improvement of turbine efficiency.The end wall secondary flow has a great influence on the mainstream,and the flow angle at the outlet of the last stage is still affected by the end wall secondary flow.After considering the seal clearance,the leakage rate accounts for a very large proportion.The leakage at the first diaphragm seal reaches 7.4%of the total flow.And the total-static efficiency of the turbine also decreases by 7.27%.The research results can provide reference for the design of supercritical CO_(2)units.

关 键 词：超临界CO_(2) 轴流透平 流动特性 流动损失 

分 类 号：TK14[动力工程及工程热物理—热能工程]