NOx emissions in a swirled-stabilized magnesium flame

Andrieu, Adeline; Allgaier, Olivier; Leyssens, Gontrand; Schönnenbeck, Cornélius; Brilhac, Jean-François

doi:10.1016/j.fuel.2022.124011

Cited by 10 publications

(3 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Generally, there are several NOx formation pathways in methane combustion, including thermal NOx, prompt NOx, and the minorities of the N2O route and the NNH pathway (Glarborg et al, 2018). Thermal NOx is influenced by flame temperature, oxygen concentration and residence time (Andrieu et al, 2022) while prompt NOx is controlled by radical concentration (Fenimore, 1971). Since combustion provides high-temperature environment (usually above 1700 K), the temperature-related thermal NOx is usually the most important source of NOx.…”

Section: Effects Of Hydrogen Addition On No X Formation In a Nonpremi...mentioning

confidence: 99%

“…Bowman, 1995) were chosen for the better accuracy in NO prediction (Barlow et al, 2001). Table 3 lists the key reaction of each NOx formation pathway (Fenimore, 1971;Malte et al, 1974;Bozzelli et al, 1995;Andrieu et al, 2022) and their reaction number in GRI-Mech 2.11 (C.T. Bowman, 1995).…”

Section: Governing Equationsmentioning

confidence: 99%

“…Thermal NOx is the reaction between N2 and atomic O at high temperatures. Such a reaction has high activation energy, approximately 75 kcal/mol (Andrieu et al, 2022), so the reaction is strongly related to temperature. The low-NOx combustor is acceptable for methane combustion; however, it is no longer satisfying for high-hydrogen combustion, especially because it cannot inhibit growing thermal NOx, meaning it hardly suppresses local high temperature ranges.…”

Section: Effects Of Hydrogen Addition On Thermal Noxmentioning

confidence: 99%

See 2 more Smart Citations

Effects of hydrogen addition on NOx formation in a non-premixed methane low-NOx combustor

CHENG,

ZHU,

DENG

2024

Mechanical Engineering Journal

View full text Add to dashboard Cite

Hydrogen is a promising carbon-free fuel, but nitric oxides (NO x ) emissions are significantly increased with higher temperature in hydrogen combustion. Internal flue gas recirculation (IFGR) is one of the most effective NO x reduction techniques in boilers. Previous research has widely reported NO x generation with hydrogen enrichments from a chemical kinetic perspective, however, the NO x formation principles in non-premixed methane/air combustion using IFGR with hydrogen addition are still unclear. This work aims to investigate the effects of hydrogen addition on NO x formation in a non-premixed methane low-NO x combustor using IFGR. The Reynolds-averaged Navier-Stokes (RANS) simulations were conducted on a 5 kW non-premixed combustor with IFGR rate of 17.7%, which generated 11.3 mg/m 3 of total NO x generation in methane combustion. A series of three-dimensional computational fluid dynamics (CFD) simulations with detailed mechanisms was tested on four hydrogen power fractions. The reaction intensities of the main NO x formation pathways were analyzed on reaction rates. The results show that 70% hydrogen power fractions lead to significantly greater NO x concentration to 677.8 mg/m 3 , as high as 60 times of the original concentration. With no additional techniques, the original methane low-NO x combustor is only allowed for hydrogen addition of less than 20% power fraction. The NNH route becomes the second dominant pathway in hydrogen-added flames. Influenced by the growing hydrogen contents, the generation of the NNH route is largely generated from 2 mg/m 3 to 65 mg/m 3 . This work connects the hydrogen addition and the NO x formation pathways in non-premixed methane combustion, and highlights the importance of eliminating thermal NO x and the NNH route to achieve low-NO x combustion rather than sole NO x suppression method, which can provide a reference for designing low-NO x techniques.

show abstract

Section: Effects Of Hydrogen Addition On No X Formation In a Nonpremi...mentioning

confidence: 99%