双背压汽轮机不等长末级叶片低压缸效率计算方法研究

Research on Calculation Method for Efficiency of Low Pressure Cylinder with Unequal Length Last Stage Blades in Double Back Pressure Steam Turbines

在某些背压条件下,双背压汽轮机的2座低压缸采用不同长度的末级叶片,可以获得更好的宽负荷节能效果。但是,在汽轮机热力性能验收试验中,无法使用传统方法计算低压缸效率。基于汽轮机工质质量平衡与能量平衡,提出了新的不等长末级叶片低压缸的效率计算方法,该方法可应用于新设计条件下低压缸效率计算。

Under certain back pressure conditions,the two low-pressure cylinders of a dual back pressure steam turbine use different lengths of final stage blades,which can achieve better wide load energy-saving effects.However,in the thermal performance acceptance test of steam turbines,traditional methods cannot be used to calculate the efficiency of low-pressure cylinders.This article proposes a new efficiency calculation method for low-pressure cylinders with unequal length last stage blades based on the mass balance and energy balance of steam turbine working fluids.This method can be applied to the efficiency calculation of low pressure cylinders under new design conditions.