EFFECTS OF EQUIVALENCE RATIO ON THE OFF-DESIGN COMBUSTION PERFORMANCE OF ADJUSTABLE FUEL FEEDING COMBUSTOR FOR A MICRO-GAS TURBINE

摘要

To improve off-design operation performance of micro-gas turbine, we proposed an adjustable fuel feeding combustor (AFFC), and it employed the lean premixed swirling combustion technology and the adjustable fuel feeding method (AFFM). The AFFM was achieved by switching the various working groups of main fuel tube, and represented by its unique characteristic number (U). To verify the availability of adopted models, the AFFC combustion performance was investigated numerically at different equivalence ratios (Φ) in ANSYS CFX. The results indicate that NO emission has various trends with the rising U under different Φ due to the coupling influence of fuel flow and jet velocity in each working main fuel tube. Although the AFFM has almost no effect on the distribution of outlet temperature and the length of primary recirculation zone, the maximum and non-uniform coefficient of outlet temperature increase with the rising U.