Demonstration of Model-Based, Off-Line Performance Analysis on a Gas Turbine Air Compressor

This paper presents a model-based, off-line method for analyzing the performance of individual components in an operating gas turbine. This integrated model combines submodels of the combustor efficiency, the combustor pressure loss, the hot-end heat transfer, the turbine inlet temperature, and the turbine performance. As part of this, new physics-based models are proposed for both the combustor efficiency and the turbine. These new models accommodate operating points that feature the flame extending beyond the combustor and combustion occurring in the turbine. Systematic model reduction is undertaken using experimental data from a prototype, microgas turbine rig built by the group. This so called gas turbine air compressor (GTAC) prototype utilizes a single compressor to provide cycle air and a supply of compressed air as its sole output. The most general model results in sensible estimates of all system parameters, including those obtained from the new models that describe variations in both the combustor and turbine performance. As with other microgas turbines, heat losses are also found to be significant.