某电厂600MW火电汽轮机低压排汽缸导流环优化

Optimization of Low Pressure Discharge Cylinder Guide Ring of a 600 MW Thermal Turbine in Power Plant

文章通过三维数值计算方法对福建某电厂600 MW火电汽轮机低压排汽缸进行了整缸流场数值模拟,结果表明,原始导流环型线具有优化改进的空间,并得出了优化方案,其静压恢复系数相对于原始扩压管而言,从-53.6%提高到11.70%,效果非常显著。同时,在排汽缸上半增加导流肋板,进一步改善该区域的排汽流动,从而增加排汽缸的静压恢复能力。改造后末级动叶后静压降低,低压模块可以增加焓降7 kJ/kg左右,在100%THA工况流量下,可以增加功率约2100 kW;相对原始热耗7900 kJ/kW·h而言,可以降低热耗值大概为27 kJ/kW·h。

In this paper,the whole cylinder flow field of the low-pressure exhaust hood of a 600 MW thermal power turbine in a power plant in Fujian is numerically simulated by three-dimensional numerical calculation method.The results show that the original guide ring profile has room for optimization and improvement,and the optimization scheme is obtained.Compared with the original diffuser,its static pressure recovery coefficient is increased from-53.6%to 11.70%,and the effect is very remarkable.At the same time,guide ribs are added to the upper half of the exhaust hood to further improve the exhaust flow in this area.The addition of rib plate can further improve the exhaust flow in the upper half of the exhaust hood,which is the cause in the static pressure recovery capacity of the exhaust hood.After modification,the static pressure of the last stage rotor blade is reduced,and the enthalpy drop of the low-pressure module can be increased by about 7 kJ/kg,and the power can be increased by about 2100 kW;at 100%THA flow rate.Compared with the original heat consumption of 7900 kJ/kW·h,the heat consumption can be reduced by about 27 kJ/kW·h.