Flashback, Blow Out, Emissions, and Turbulent Displacement Flame Speed Measurements in a Hydrogen and Methane Fired Low-Swirl Injector at Elevated Pressures and Temperatures

This paper reports on a work in progress study measuring flashback, blow out, emissions and turbulent displacement flame speeds in a low swirl injector operated at elevated pressures and inlet temperatures with hydrogen and methane based fuels in an optically accessible combustor rig. The goal is to extend the knowledge of low-swirl flames at conditions relevant to gas turbine engines. Testing was conducted at pressures ranging from 3 to 6 atm, inlet temperatures from 290 to 600K, and inlet bulk velocities from 20 to 60 m/s for natural gas and a 90%/10% by volume hydrogen/methane blend. Blow out limits for natural gas were found to be independent of pressure and inlet temperature but weakly dependent on velocity. Flashback limits for hydrogen were found to be independent of inlet temperature but strongly dependent on velocity and pressure. Local displacement turbulent flame speeds for methane were measured and appear to coincide with atmospheric pressure data in the literature. NOx emissions for both fuels were found to be exponentially dependent upon firing temperature, but emissions for the high hydrogen content flames were consistently higher than natural gas flames.Copyright © 2012 by ASME