Combustion Performance of Contaminated Marine Diesel Fuels in a T63 Gas Turbine Combustor.

Abstract : The combustion performance of 26 fuel blends of Navy distillate fuel (NDF), heavy marine gas oil (HMGO), and a Jet A reference fuel contaminated with residuals containing various concentrations of asphaltenes, resins, and ash was measured in a T63 gas turbine combustor rig. Combustion performance measurements included could start ignition, combustion efficiency, gaseous exhaust emissions, flame radiation, exhaust smoke, liner temperature, and combustor can deposit formation. Except for ignition, these measurements were made at 4 operating conditions, 10% of full power (idle), 55, 75, and 100% of full power. Cold-start ignition measurements were made on 9 of the test fuels at burner inlet air temperatures ranging from 238K to 300K and fuel temperatures ranging from 263K to 300K. Droplet size measurements were made of fuel sprays from the T63, LM2500, DDA 501-K17, and the TF40B atomizers using a Malvern light scattering apparatus. These measurements were made on 7 fuels over a range of low fuel flow rates comparable with those used for the ignition conditions of the respective engines. Correlation equations were developed relating Sauter mean droplet diameter to fuel properties and flow conditions. The correlation equation developed for the T63 atomizer was used in a characteristic time model calculation of the cold start ignition data. Flame radiation and exhaust smoke correlated with hydrogen-carbon ratio. Fuels contaminated with residuals did not deviate significantly from the H/C ratio correlation. When neat NDF and HMGO were contaminated with residuals there appeared to be a slight decrease in combustion efficiency and increase in total hydrocarbon and CO emissions.