燃气透平第一级冷却空气系统流体的动力特性

Fluid Dynamic Characteristics in First Stage Cooling Air System of a Gas Turbine

将燃气透平冷却空气系统模化为由大量不同通流单元以串连或并联方式组成的复杂网络系统,采用有向图的关联矩阵描述了该复杂网络的结构特征;选用适当的试验关联式计算空气流经各通流单元的压力损失与换热量,并建立了冷却空气流动与换热特性的流量、压力和温度方程组;采用逐步简化冷却空气网络系统的方式,求解冷却空气系统内流量的分配;采用以改进并修正的高斯消去法为基础的一种稳定的大型稀疏矩阵线性方程组来求解冷却空气系统内空气的压力与温度分布;在此基础上,编制出冷却空气系统流动特性的通用计算程序,并对某燃气透平第一级冷却空气系统特性进行了计算与分析,结果表明:第一级静叶与动叶的冷却空气消耗量分别占空气流量的3.97%和2.88%,与文献报道的同类型机组(西门子V94.3)的数值接近.

Cooling air system of a gas turbine was simulated as a complicated network system composing of different throughflow elements connected in series or parallel,of which the configuration features were described by incidence matrix of directed graph according to relevant network topology relations.Pressure loss and heat transfer rate of the air flowing through each element were respectively calculated using available empirical relations,while equations describing fluid dynamic and heat transfer characteristics presented,such as for the fluid flow,pressure and temperature etc.Governing equations were solved for the flow distribution of cooling air by simplifying the network system step by step,and large sparse matrix linear equations based on Gauss Elimination for the pressure and temperature distribution by a stable solution method.On above basis,a universal calculation program for fluid dynamic characteristics of cooling air systems was developed and applied for the first stage cooling air system.Results show that the air consumption of the first stage stator and rotor blade, which respectively accounted for 3.97% and 2.88% of the total air volume,are close to published data of similar power units（like Siemens V94.3）.