Investigation into the thermodynamic suitability of a commercial turbocharger for use in a micro gas-turbine

Abstract

Micro gas-turbines are expanding to be much more prevalent in the power generating market. They are merely scaled down versions of their larger siblings, gas-turbines powering commercial airplanes on generating megawatts of electrical energy throughout the world. The basic components of a micro gas-turbine and that of a turbocharger unit on internal combustion engines are quite similar. Both have a compressor, a heat source and a turbine. This study investigates the possibility of using a commercial turbocharger, designed for use on internal combustion engines, to function as a micro gas-turbine. The literature study discusses the components that make up a typical gas-turbine. Importantly, the literature explains the principles of operation and thermodynamic and/or mechanical relevance in a gas-turbine. Furthermore, the study shows a hand calculation procedure in order to calculate the excess power available from a turbocharger based on a fixed turbine inlet temperature, calculating the excess power for four different turbocharger Units. After the compressor and turbine characteristics are imported into FLOWNEX (a network solving software package) to recalculate the excess power, the results are compared with the results of the hand calculation. A specific turbocharger is selected to incorporate into a recuperated open cycle gas-turbine simulation. The cycle is firstly calculated by hand after which it is simulated in the Engineering Equation Solver (EES) to facilitate ease of modifications to the input parameters. The results from the cycle simulation are then compared to preferred system parameters. The conclusion is then made that a turbocharger is thermodynamically suitable to function as the core element of a microgas-turbine.