变几何燃气轮机性能的计算分析

Calculation and Analysis of the Performance of a Variable Geometry Gas Turbine

为了分析不同涡轮变几何时的机组性能,基于小偏差方程提出了一种研究变几何燃气轮机性能的新方法。应用该方法计算了不同涡轮通流面积的相对变化量在±5%时的机组性能,并从理论上进行了分析。分析表明:在简单循环机组中,无论是高压涡轮、低压涡轮还是动力涡轮变几何,对系统经济性的影响都不大,但会影响压气机平衡运行线,其中低压涡轮变几何对低压压气机平衡运行线的影响较大,高压涡轮和低压涡轮变几何对高压压气机平衡运行线的影响较大。

To analyze the performance of a unit when its turbine is being geometrically changed,proposed was a new method for studying the performance of variable geometry gas turbines based on a small deviation equation.By using the method,the unit performance was calculated when the relative change of different turbine flow path areas is within ±5% and a theoretical analysis has been performed.The analytic results show that in simple cycle units,whether a HP turbine,LP turbine or geometrically changed power turbine is used,it will have little influence on the cost-effectiveness of the system but will affect the equilibrium operating lines of the compressor.Among others,the variable geometry of the LP turbine will have a relatively big influence on the equilibrium operating lines of the LP compressor while that of both HP and LP turbine will also exercise a relatively big effect on the same operating lines of the HP compressor.