Flow Analysis Procedure for Steam Turbines

Abstract

Abstract An algorithm (computational procedure) for flow analysis of steam turbines is presented. The algorithm is specially designed for analysis of low pressure turbines but is applicable in the same way for high pressure turbines. The analysis of the flow is carried out stage by stage (or row by row). The algorithm is so designed that a turbine of known geometry can be assessed with respect to its throughput (flow) and performance capabilities at arbitrary flow rates and steam conditions. The performance parameters include stage efficiency, rotor blade loading, blade section efficiency, and all aero/thermodynamic parameters within the blade path. On the other hand the algorithm can be used for turbine design purposes. The algorithm deals with 2D flow. The analysis starts from the last stage and proceeds up-stream. There are several iteration loops where the mass flow is computed and compared to a required value. The algorithm is capable of determining stage flow given the stage pressure and vice versa. The algorithm can be expanded to assimilate new capabilities (for example: radial equilibrium applied to rotor). The algorithm can be applied especially for upgrading the turbines of older design.