An Object-Oriented Program for the Dynamic Simulation of Gas Turbines

Abstract

An object-oriented program for the dynamic simulation of gas turbines has been developed using Matlab-Simulink® utilities. The advantages given by the object-oriented program are the flexibility and the user-friendly interface. The components of the gas turbine are modeled as blocks that can be assembled like an engineering drawing in which the connections between two elements represent either a mechanical power transfer or a fluid transfer. In a fluid-type connection the data regarding the fluid composition, the thermodynamic properties and the fluid velocity are simultaneously transferred. A library of gas turbine components has been developed: each component appears as a block that can be placed into the drawing by means of click-and-drag operations. In order to obtain an accurate description of the physical processes characterizing the gas turbine, the components are described by a set of non-linear algebraic equations and ordinary differential equations. Each component block is created using the graphical programming tools of Simulink, following a block diagram approach. Specific blocks have been created for the evaluation of the thermodinamic properties of the working fluids. The paper provides the description of the mathematical model adopted for the simulation and the some examples of the Matlab-Simulink formulation adopted for implementing the model. The accuracy of the program has been verified considering test cases for which experimental data are available in the public literature. The computational times, tested for the transients of a single-shaft and a double-shaft gas turbine, resulted to be very short, even making use of a personal computer.