NASA’s Glenn Research Center has developed a novel design for a fully premixed, high-pressure burner capable of operating on a variety of gaseous fuels and oxidizers, including hydrogen-air mixtures, with a low pressure drop. The burner provides a rapidly and uniformly mixed fuel-oxidizer mixture that is suitable for use in a fully premixed combustion regime that has the benefits of low pollutant emissions (when operated at fuel lean conditions) and freedom from harmful flashback effects, combustion instabilities, and thermal meltdown problems that are normally associated with premixed combustion systems operating at high pressures.
The novel burner technology has been demonstrated to operate on hydrogen-air mixtures at pressures up to 30 bar and at equivalence ratios (Phi) ranging from 0.15 to 5.0, but typically at equivalence ratios below 0.6 or above 2.0 for extended periods of time. It has also been demonstrated to work well with hydrogen-carbon monoxide fuel mixtures in a 1:1 mixture (by volume). The design provides a uniform zone of combustion products and temperatures, and is able to achieve complete and rapid mixing of the reactant gases over a distance as short as 5 mm, with the combustion products reaching a fully reacted state within about 10 mm downstream of the burner face. Furthermore, the design of the burner, which utilizes high-speed jets to prevent flashback, is simple and straightforward to manufacture using conventional techniques. The modular design of the burner lends itself to scalability for larger power output applications. Finally, the burner is simple to operate and is robust for use in an industrial setting, such as a low-emissions stationary gas turbine engine, or for aircraft gas turbine engines.