EFFECTS OF FUEL-NOZZLE CONFIGURATIONS ON PARTICULATE-MATTER EMISSIONS FROM A MODEL GAS TURBINE COMBUSTOR

摘要

The present paper describes particulate-matter (PM) emissions from a model gas turbine combustor at atmospheric pressure, focusing on the effects fuel-nozzle configurations have on PM emissions. In this experiment, three types of fuel nozzles were employed: standard, annular, and multi-type. The annular and multi-type were designed as low-PM-emission fuel nozzles, based on our preliminary experimental results using the standard nozzle. Gas oil and fuel oil containing 0.2 wt% of carbon residue were used as the test fuels. The PM concentrations and particle-size distributions were measured with an electrical low-pressure impactor. The experimental results revealed that the PM concentrations for the annular and multi-type were dramatically reduced compared with that for the standard nozzle, demonstrating their PM-reducing effect. We found that the high-concentration regions seemed to be formed by soot aggregation, from the spatial-profile measurements of PM emissions from gas oil combustion. The high-concentration regions for the low-PM-emission fuel nozzles were located further upstream and they were on a smaller scale than that for the standard nozzle. This suggests that their PM-reducing effect may be due to their upstream location and the smaller-scale of their high-concentration regions.