Simulation of Flow Over of a Gas Turbine Compressor Blade Running on Air and Syngas

Abstract

There has been an increase in demand for electricity globally. Gas turbines run ning on syngas are being used to generate electricity. This is because syngas is a renewable source of energy. As of 1999, General Electric (GE) had twelve gas turbines in operation using syngas in Delaware and Singapore. Though gas tur bines using syngas are in use, there is little literature showing the performance of the compressors in the gas turbines and specifically centrifugal compressors. This research focused on the performance of a centrifugal compressor running on syngas and compared its performance with that running on air. The syngas used was a mixture of carbon monoxide (CO) and hydrogen (H2). The centrifugal compressor designed was unshrouded with 15 main blades at a backsweep angle of 450 and a vaneless diffuser. An initial rotational speed of 22,000 RPM was input with a mass flowrate 0.167 kg/s for air. An inlet pressure and temperature of 1 bar and 298 K respectively were also input. These values were obtained from literature. Total heat transfer was chosen and turbulence model used was shear stress transport. The re sults showed that at low mass flow rates and high rotational speed, air as a medium generated recirculation regions as compared to syngas. The centrifugal compressor using air had recirculation regions from 20% span all the way to 80% span while for syngas the recirculation was at 80% span. Air velocity reached a maximum of 50 m/s for air and 140 m/s for syngas. For syngas, the pressure contours showed a decrease in pressure through the meridional passage while for air, there was a pres sure increase. This research can be applied to industries working with syngas gas turbines for power generation, and compressing syngas for domestic use. Research can be further streamlined to focus on using syngas as a fuel for automobiles.