高中压合缸汽轮机过桥汽封内泄漏流动的数值研究

Numerical Investigation of Central Gland Leakage Flow for a Combined HP-IP Casing Steam Turbine

基于ANSYS CFX,研究了某超临界600MW高中压合缸汽轮机过桥汽封内蒸汽的泄漏流动。分析了转子的旋转对过桥汽封漏汽量的影响,结果显示,转子的旋转将使过桥汽封处蒸汽的泄漏量略有降低;数值计算得到了不同工况下过桥汽封处的漏汽量,并与理论公式的计算结果和设计值进行了比较,结果表明:数值计算的结果略大于理论公式的计算结果和设计值,且3种结果都显示过桥汽封处的漏汽量将随着负荷的增加近似呈线性增长的变化趋势;此外,不同负荷条件下,高压缸进汽侧汽封漏汽量与主蒸汽流量的比值和中压缸进汽侧汽封漏汽量与再热蒸汽流量的比值都基本为一定值。

This work presents a numerical investigation of central gland leakage flow for a supercritical 600MW steam turbine with combined HP-IP casing based on ANSYS CFX. The effect of the rotation of rotor on the central gland leakage is analyzed. The results show that the rotation of rotor reduces the central gland leakage slightly. Central gland leakages under different operating conditions are obtained by numerical calculation. A comparison of results calculated by numerical simulation and theoretical formula and design values is conducted. It indicates that numerical results are larger than other two results. Three results all show a nearly linearized variation of central gland leakage to the load of steam turbine. In addition, the ratio of leakage of gland seal on the HP admission side to the main steam flow and the ratio of leakage of gland seal on the IP admission side to reheated steam flow are essentially constant values.