Palm biodiesel spray and combustion characteristics in a new micro gas turbine combustion chamber design

Abstract

Micro gas turbine (MGT) is one of the main candidates for green distributed cogeneration since it allows the utilization of wider range of renewable fuel sources. A new chamber geometry was designed and optimized for liquid biofuels combustion. Prior to the testing of the chamber, a cold-flow fuel atomization test rig was tested with different fuel injector sizes covering flow range of 50–200 ml/min. Spray characteristics of palm biodiesel were investigated and compared to diesel as the benchmark. The chamber was then tested with diesel fuel followed by biodiesel in a single-stage MGT configuration. Turbine inlet temperature (TIT) was limited below 900 °C to avoid damaging turbine blades, thus, limiting the operating gauge pressure below 0.6 bar. A Power turbine with high-speed alternator and heat recovery unit (HRU) were then added to the test rig in a combined heat and power (CHP) configuration. The lab-scale MGT-CHP system was fully characterized in the pressure range of 0.1–0.4 bar and achieved overall efficiency of 24.7% and total NOx emissions range of 22–70 ppm with palm biodiesel.