Towards real time transient mGT performance assessment: effective prediction using accurate component modelling techniques

Abstract

In an energy mix driven by renewables, there is a need for small-scale highly efficient and flexible cogeneration units, such as Micro Gas Turbines (mGTs). These mGTs should perform transient operations and work at part-load to meet the power grid requirements. Therefore, full transient characterisation is necessary. One of the most crucial factors is accurately incorporating each component's dynamic behavior. Compressor and Turbine performance maps, although essential, are usually obtained in costly test rigs or CFD simulations. Also, the accurate modelling of the heat exchanger affects the efficiency of the whole cycle. The aim of this work is the development of real time transient mGT model, where we focus in the first step on accurate component modelling. Hence, an effective performance map representation method for mGT's compressor and turbine was developed. Moreover, a Recuperator 1-D numerical model is developed. Those modelling techniques were tested in a MATLAB/SIMULINK model in transient conditions. The fundamental target of this study is to enhance the fidelity of dynamic simulations for small-scale gas turbines. Key parameters like shaft speed and combustor inlet temperature, show deviation from experiments less than 1% which solidifies our aim to establish a general and efficient performance prediction.