Combustion Characteristics of a Multiple-Injection Combustor for Dry Low-NOx Combustion of Hydrogen-Rich Fuels Under Medium Pressure

Abstract

An oxygen-blown integrated coal gasification combined cycle (IGCC) plant with pre-combustion carbon dioxide capture and storage (CCS) is one of the most promising means of zero-emission generation of power from coal. In an IGCC plant with CCS, hydrogen-rich syngas with a wide variation of hydrogen contents is supplied to a gas turbine. Such hydrogen-rich syngas poses a great challenge to a low NOx combustor based on premixed combustion technology, because its high flame speed, low ignition energy, and broad flammability limits can cause flashback and / or auto-ignition. On the other hand, a diffusion combustor suffers from the high flame temperature of syngas and the resulting high NOx emission. The authors applied a “multi-injection burner” (cluster burner) concept to a preliminary burner for hydrogen-rich syngas simulating that from IGCC with CCS. In a preliminary experiment under atmospheric pressure, the multi-injection burner worked without any flashback or any blowout. A prototype multi-cluster combustor based on the results of that preliminary study was made to be a dry low NOx combustor for hydrogen-rich syngas of IGCC with CCS. It was tested in experiments, which were carried out under medium pressure (0.6MPa) using test fuels simulating syngas from IGCC with a 0% carbon capture rate, a 30% carbon capture rate and a 50% carbon capture rate. The test fuels contained hydrogen, methane and nitrogen, and had hydrogen content ranging from 40% to 65%. The following conclusions were drawn from the test results: (1) The tested combustor allows stable combustion of fuels simulating 0%, 30%, and 50% CCS. (2) A convex perforated plate swirler is effective to suppress combustion oscillation, which allows NOx emissions to be less than 10ppm through the variation of fuel simulating 0%, 30% and 50% CCS.

Review of Fuel/Oxidizer-Flexible Combustion in Gas Turbines

“…Using air−H 2 combustion, they have reported a strong correlation between the flamelet anchoring mechanism and the formation of NO x . Dodo et al 84 have tested the MM of an integrated gasification combined cycle (IGCC) using H 2 -rich syngas−air combustion at a medium pressure of 0.6 MPa. They have used fuels that contained CH 4 , H 2 , and nitrogen, with three carbon-capture rates (0, 30, and 50%).…”

Frontiers in combustion techniques and burner designs for emissions control and CO2capture: A review

“…Lean Direct Injection (LDI) was found to drastically reduce the risk of flashback in H 2 combustors. 244 The combustion of high-H 2 fuels using air in MMs has been examined in past studies, [238][239][240] but never under oxycombustion conditions. Miniature-scale distributed premixer arrays, aka MMs, were developed and tested in several studies, in order to reduce NO x emissions safely with H 2 -rich fuel.…”

“…The results showed significant effect of flame stabilization mechanism on NO x emissions. Dodo et al 240 tested MM air-combustion of IGCC-syngas fuel simulants containing hydrogen, methane, and nitrogen with a hydrogen content of 40% to 65%. Three fuel blends were considered with 0%, 30%, and 50% carbon-capture rate.…”

“…Some of the examined configurations were jetin-crossflow mixing, 242 co-flow mixing, 243 and swirlinduced mixing in miniature cups with axial and radial inflow. 244 The combustion of high-H 2 fuels using air in MMs has been examined in past studies, [238][239][240] but never under oxycombustion conditions. Hernandez et al 245 natural gas/air ones in MMs.…”

Review of Novel Combustion Techniques for Clean Power Production in Gas Turbines

“…They showed that the anchoring mechanism of the flamelets has a strong impact on NOx formation. Dodo et al 172 tested micromixer air combustion of IGCC-syngas fuel simulants containing hydrogen, methane, and nitrogen with a hydrogen content of 40−65%. Three fuel blends were considered with 0, 30, and 50% carbon-capture rate.…”