Component Matching Analysis for a Power Generation Gas Turbine: Classroom Applications

One analysis that is often overlooked in the gas turbine classroom is that of component matching. Some “student friendly” analyses have been published for gas turbines with propulsion applications, including modeling of the components for computer analyses. To complement the propulsion analyses, a method of matching gas turbine components for an aeroderivative power generation gas turbine is presented in this paper. Matching is the process by which components are integrated to allow predictions of overall gas turbine performance. The fundamental method of matching components with generalized characteristic maps is first described. A single shaft power generation gas turbine (inlet/gas generator/regenerator/exhaust/shaft/load) is used. Matching is accomplished by simultaneously solving the matching closure equations along with the component maps (either mathematical models or graphical data). The method is demonstrated for an example moderate sized power generation unit with given inlet, compressor, burner, turbine, regenerator, exhaust, load, and shaft maps. Improvements with the inclusion of the regeneration unit are included. For the example, a range of fuel ratios was used and the unit was shown to increase in rotational speed and the compressor eventually surged as the fuel ratio was increased. Overall thermodynamic efficiency, power output, mass flow rate, rotational speed, and other overall and component parameters are shown as functions of the fuel flow rate. The technique lends itself well in the classroom so that students can appreciate the interdependence of the component performances. The technique is a tool in which a student can select components to optimize the overall performance and can predict off-design performance of a power generation unit.