Investigation On The Influence Of Variable Geometry Compressor On Operating Performance Of Gas Turbine

As one of the anti-surge technique, the adjusting scheme of VSV under off-design conditions has a significant impact on the performance of gas turbine. With the limitation of time and cost, it is difficult to study the adjusting scheme of VSV with experimental method under a wide operating range. With the development of the Gas turbine simulation, integrated simulation technology is used to study the simulation of whole or part of gas turbine from different views and levels. It has become an effective way to study performance of the gas turbine. So in this paper, the variable dimensions (0-1D) for overall simulation model of gas turbine which considered the performance of variable-geometry compressor is established. To improve the operating efficiency of the gas turbine, an adjusting scheme of the first three rows of VSV has been optimized. Then the steady and dynamic performance of gas turbine is studied based on the influence of VSV. The study has provided references for the adjusting scheme of VSV under gas turbine off-design conditions operating process.The main works of this paper are as following:(1) Based on modular modeling, the object studied has been divised reasonably and the mathematical model of marine gas turbine components has been established. For variable geometry compressor characteristics changes, a new compressor characteristic module and scaling interface module is established. One-dimensional characteristic of compressor calculation program is embedded into zero dimensional overall gas turbine model, which replaces the original compressor characteristic module.(2) Based on the assembling relationship of the actual components of the marine gas turbine, the architecture of the modular model library is designed. Accordingly under the MATLAB/Simulink software environment, the marine gas turbine simulation model library including compressor, combustion chamber and turbine, rotor, volume module is established.Finally the consideration of variable geometry compressor variable dimension simulation of gas turbine model has been set up. At the same time, an integrated simulation platform of marine gas turbine is developed by using Matlab/GUI software.(3) The influence of the first 3 rows of variable stator vanes of the 9-stage axial compressor working alone on the performance of the compressor at different speeds and different angle was analyzed by the HARIKA compressor characteristic calculation program.Taking the economic and stability of gas turbine as the optimization objective, the optimization of the first three stage stator vanes regulation schemes under different working conditions was carried out. The steady-state performance parameters under each working condition of gas turbine of power generation with or without variable stator vane mode were calculated. The steady state simulation results under these two gas turbine operating modes are compared and analyzed.(4) With the established simulation model of variable dimension marine gas turbine, the changing characteristics of the gas turbine power generation system under typical operation conditions has been studied. The dynamic operating characteristics between original stator vanes scheme and the optimization scheme of the gas turbine are compared and analyzed.