Numerical simulation of a mild combustion burner

Studies on a new high-intensity low-emission burner

“…The NO emissions increase mildly with the increase in the power level. Although the emissions from the system are comparable to the earlier experiments [2,4,5,14], the heat release rates are significantly (10-50 times) higher. Similar reductions of NO x emissions are noted by Fujimori et al [15] from lifted jet diffusion flames with high-temperature coflowing air, when the liftoff height exceeded the attached flame length.…”

“…The heat release rates in the previous experiments [2,4,5,7,11] are very small, varying from 23 to ϳ320 kW/m 3 as shown in Table 1. It is the aim of the combustion system design to achieve high heat release rates while meeting the requirement of low emissions.…”

“…Many techniques, such as flame cooling, staged combustion, reburning, and exhaust gas recirculation, are proposed to reduce NO x emissions [1]. The exhaust gas recirculation for NO x reduction is drawing interest because of its promising features [1][2][3][4][5][6]. In this method, combustion products are recirculated and mixed into the fresh incoming fuel and air streams.…”

“…Recuperation and/or regeneration are used to preheat the incoming air to high temperatures. In several of these studies [2,4,5], reverse-flow geometry has been used to create the flameless combustion phenomenon; the aerothermochemical features are mapped at high recirculation rates to quantify the operational characteristics of the burner under different operating conditions in premixed (lean and rich) and non-premixed regimes. Experiments indicated that flameless combustion falls in a stirred reactor regime where simultaneous ignition and extinction phenomena are absent [2].…”

Kinetic and fluid dynamics modeling of methane/hydrogen jet flames in diluted coflow

“…Coelho and Peters [8] carried out numerical simulation on MILD combustion FLOX burner and showed that the steady flamelet library was unable to correctly describe the formation of NO. In fact, NO formation is a slow process, and therefore is sensitive to transient effects.…”