Abstract
With increased pressure for conventional coal-fired power plants to adopt a flexible operating principle, an increased need for computationally inexpensive thermal and structural turbine models has been observed. This paper documents the formulation of a paired thermofluid and FEA turbine modelling methodology to predict the radial and axial clearances within a 600MW candidate steam turbine during a full cold start procedure. This study formulates a method for sizing and modelling a representative turbine with limited OEM input through the implementation of the Nozzle Analogy theory for axial, multistage steam turbines. Following the development of a full turbine process model and representative 3D FEA turbine model, a successful validation of key turbine temperatures and differential expansions was carried out using real-world plant data within a high level of accuracy. The modelling methodology presented a computationally inexpensive method to predict internal turbine temperature boundaries as well as the structural behaviour of turbine components under transient loads, and proved invaluable in a thorough understanding of flexible turbine operation.
