基于汽轮机相对内效率分析的低压缸效率计算  

Calculation for Low Pressure Cylinder Efficiency Based on Analysis of Relative Internal Efficiency of Steam Turbine

作　　者：冯垚飞 冯林魁 谷志德 赵凯 王平 FENG Yaofei;FENG Linkui;GU Zhide;ZHAO Kai;WANG Ping(Electric Power Research Institute of State Grid Gansu Electric Power Company,Lanzhou 730070,China)

机构地区：[1]国网甘肃电力公司电力科学研究院,甘肃兰州730070

出　　处：《电力科学与工程》2022年第9期74-78,共5页Electric Power Science and Engineering

摘　　要：为分析汽轮机运行经济性,在进行常规低压缸效率计算时,需要反复迭代低压缸膨胀线终点焓直至收敛;该计算过程较为复杂。通过汽轮机组各缸的等熵膨胀线与各段抽汽压力的交点计算出等熵状态下回热抽汽点的焓值;利用回热系统能量、质量平衡方程计算等熵状态下各段等熵回热抽汽流量,并将轴封漏汽损失修正至等熵状态下;根据汽轮机整体热量平衡计算准确得到汽轮机相对内效率,再通过汽轮机相对内效率与缸效率之间的等效关系间接地求得低压缸效率。以不同功率凝汽式机组为算例,将变工况计算结果与常规标准算法进行对比,发现所提出的方法计算精度良好、误差范围小。In order to analyze the economy of steam turbine operation,it is necessary to iterate the end enthalpy of expansion line repeatedly until the calculation is converged when calculating the conventional low pressure cylinder efficiency,and the calculation process is complex.The regenerative extraction enthalpy under isentropic state can be calculated by the intersection of isentropic expansion line of each cylinder of the steam turbine unit and extraction pressure of each section,and the flow for regenerative extraction of each section under isentropic state is derived by means of energy and mass balance equation of regenerative system,and steam leakage loss of shaft seal is also corrected to isentropic state.The relative internal efficiency of steam turbine is obtained accurately based on the calculation of overall heat balance of the turbine,and efficiency of low pressure cylinder can be calculated by the equivalent relationship between the relative internal efficiency of steam turbines and cylinder efficiency.Taking condensed turbine unit with different capacities as calculating example,compared with the conventional standard algorithm,the proposed calculation has high accuracy and small error range.

关 键 词：汽轮机 相对内效率 低压缸效率 等熵 热平衡 

分 类 号：TK262[动力工程及工程热物理—动力机械及工程]