HEAVY-DUTY GAS-TURBINE PLANT AEROTHERMODYNAMIC SIMULATION USING SIMULINK

This paper presents a physical simulator for predicting the off-design and dynamic behavior of a single shaft heavy-duty gas turbine plant, suitable for gas-steam combined cycles. The mathematical model, which is nonlinear and based on the lumped parameter approach, is described by a set of first-order differential and algebraic equations. The plan t components are described adding to their steady-state characteristic s the dynamic equations of mass, momentum, and energy balances, The st ate variables are mass flow rates, static pressures, static temperatur es of the fluid, wall temperatures, and shaft rotational speed. The an alysis has been applied to a 65 MW heavy-duty gas turbine plant with t wo off-board, silo-type combustion chambers. To model the compressor, equipped with variable inlet guide vanes, a subdivision into five part ial compressors is adopted, in serial arrangement, separated by dynami c blocks. The turbine is described using a one-dimensional, row-by-row mathematical model, that takes into account both the air bleed coolin g effect and the mass storage among the stages. The simulation model c onsiders also the air bleed transformations from the compressor down t o the turbine. Both combustion chambers have been modeled utilizing a sequence of several sub-volumes, to simulate primary and secondary zon es in presence of three hybrid burners. A code has been created in Sim ulink environment. Some dynamic responses of the simulated plant, equi pped with a proportional-integral speed regulator, are presented.