Gas Turbine Integrated Conceptual Design Approach

Abstract

In order to improve performance of heavy-duty gas turbines, in terms of power, efficiency and reliability, accurate calculation tools are required. During conceptual design phase, an effective integration of main GT components design into a single modular simulation tool can significantly reduce design iterations and improve the results. Thanks to an innovative modular-structured program for the simulation of air-cooled gas turbines, the one-dimensional design of compressor and turbine flow paths is used to create a complete gas turbine model including a detailed secondary air system and a simplified heat transfer model. This zero-dimensional heat transfer model is applied to each turbine row in order to calculate the cooling flow required to keep turbine blades and vanes metal temperatures below a prescribed threshold. After a description of the air cooled gas turbine modular model, the integrated design approach adopted by Ansaldo Energia is described. The knowledge of technical risks that the designers have to withstand developing advanced technologies during conceptual engine design is fundamental. The inter-disciplinary influence of some disciplines is analyzed and finally it is shown how Ansaldo Energia approach can track expected performance results and provide recovery plans during the conceptual design phase.

Performance prediction of transonic axial multistage compressor based on one-dimensional meanline method

“…Moreover, the 1D program cannot only provide stage performance data including efficiency, pressure ratio and interblade data, but can also be integrated into the performance simulation of entire gas turbine (GT) for the precise prediction of compressor operation at off-design condition. [4][5][6] Not only that, the 1D method can predict the effect of compressor bleed offtake and inlet guide vane(IGV)/variable guide vane(VGV) setting which is of great importance in preliminary design, part-load performance in full range and dynamic behavior (especially startup characteristic) of GT cycle. 6,7 The 1D calculation methods of axial compressor mainly include stage stacking and 1D meanline methods.…”