Study on Soot Emission Characteristics of Methane/Oxygen Inverse Diffusion Flame

Abstract

Inverse diffusion flame (IDF) is an effective and widely used reaction form in the process of noncatalytic partial oxidation (NC-POX) of gaseous hydrocarbons (such as natural gas and coke oven gas). However, soot is generated in the combustion chamber in the case of unreasonable feeding conditions, and thus causes serious damage to the wall and nozzle. In this study, the effects of the equivalence ratio ([O/C] e ), the oxygen flow rate, and the Reynolds number on the soot and CH* emission characteristics of CH 4 /O 2 inverse diffusion flame were comprehensively analyzed based on a hyperspectral imaging system. In addition, the relationship between CH* and soot is explored using Ansys Fluent simulation. The experimental results show that the soot radiation core generation area is located in the outer ring of the flame, and the radial distribution of the radiation intensity is bimodal. With the increase in [O/C] e , the initial position for soot radiation and the overall radiation intensity of soot decrease. In addition, the CH* radiation intensity decreases as [O/C] e increases, and CH* exists in the whole flame. The simulation results clearly show that the existence of CH* is conducive to soot production. The emission intensity and the core area of soot formation increase with the increase in the oxygen velocity. Additionally, the soot emission region increases and the flame tip changes from a round blunt to symmetrical tip with the increase in the Reynolds number.

Simple Encoded Circularly Polarized Protein Lighting

“…[79] Similar behavior has been already noted for CNC coatings, in which the dilution of the emitter resulted in a higher g lum. [80] For reference purposes, we also carried out a control using polyvinylalcohol (PVA) polymer coating that has been used to stabilize CPL emitters in the solid state [81] and recently FPs for lighting devices. [82] Here, the FP-loading threshold to detect CPL signal was as low as 0.01 mg, reaching a g lum of −0.6 × 10 −2 (Figure S10, Supporting Information).…”

Prediction of Equivalence Ratio in Combustion Flame Using Chemiluminescence Emission and Deep Neural Network

“…However, despite the same combustion conditions, the results showed different intensity distributions in the wavelength range. Owing to the horizontal view (view 3), including the yellow and blue flame areas (see Figure 1), and the soot radiation effect [30,48], an increasing trend was observed in the range of 400-550 nm. The background effect by the blackbody radiation can be subtracted by acquiring reference measurement without the target signal, as shown in previous studies [23,49].…”

Optical Analysis of Blast Furnace Gas Combustion in a Laboratory Premixed Burner

“…22 , 26 , 27 In addition, hyperspectral cameras can also be used to measure light emissions of several radicals simultaneously. 28 …”

“…Second, research on combustion chemiluminescence can also be developed with imaging techniques. For that purpose, cameras for UV, visible (vis), and IR ranges are set up with narrow-band filters to only measure light emissions related to the relevant radicals. ,− For example, the measurement of OH* emissions with imaging techniques enables the characterization of premixed flame fronts. ,, In addition, hyperspectral cameras can also be used to measure light emissions of several radicals simultaneously …”