Abstract

Hydrogen is already widely produced and used in the industry. NOx formation during the combustion of hydrogen can be reduced by adding nitrogen. Nonetheless, this comes at the cost of decreased flame stability, which constrains the applicability of hydrogen. Therefore, the flame stabilization characteristics of nitrogen-diluted hydrogen jet flame at varying dilution concentrations (10%–50%) were investigated using thin-lipped nozzles with diameters of 2, 3, and 5 mm. The experimental results show that the nitrogen-diluted jet flame becomes bluer and the flame height and width decrease with the dilution concentration. Due to the incomplete combustion at downstream of the diluted jet flame, the classical prediction model using the dimensionless flame Froude number (Frf) overpredicts the flame height of nitrogen-diluted hydrogen jet flame. The model, ρeSLhμe=50(ueSL)g(ρeρ∞), can effectively predict the flame lift-off distance of diluted hydrogen jet flames, where SL is the corresponding laminar combustion speed in the lean mixture zone (Φ = 0.91). A unified prediction model of blowout limit based on the Damköhler number for diluted hydrogen and hydrocarbon jet flames was proposed for the first time. This study helps to better understand the instability mechanism of diluted hydrogen.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.