Influence of crosswind on efficiency of low calorific value high momentum turbulent jet flame combustion

Abstract Industrial flare systems are used to manage exhaust gases released because of accidents or during normal mode production processes. Conversion of harmful and detrimental waste exhaust fuel into harmless products eliminates the exits of harmful emissions into the environment. To address the challenge of diminished combustion performance in high cross-wind environments, this study applies CFD simulations to analyze how transverse airflows affect key combustion characteristics and overall flame efficiency. The investigation seeks to understand the underlying mechanisms and mitigate the associated efficiency losses. Based on methane and air fuel, a three-dimensional flame model is built to examine the change in temperature field and carbon dioxide mass fraction contours of the flame at varying crosswind velocity, jet velocity, and crosswind angle of the flare; in addition, the mechanism of fuel stripping at crosswind velocity is determined. The study recommends that the flare system should discharge the flare gas at the end of the study, when the ambient crosswind angle exceeds a limit. The flame combustion efficiency with varying working conditions was measured. The results indicate that as the horizontal crosswind speed ( v c ) increases from 0 m/s to 5 m/s, the flame tilts further from the vertical, its height decreases, the maximum radial width reduces, the high-temperature core shrinks, and combustion efficiency ( η c ) decreases by 46.7 %. When the horizontal crosswind speed reaches 5 m/s, part of the fuel stream is diverted by the wind, causing the flame to become discontinuous. At horizontal crosswind velocity v c = 5 m/s, combustibility efficiency was reduced by 92 % as jet velocity (v) was raised between 49.6 m/s and 70 m/s. The increase in jet speed does not effectively reduce the cross-wind influence on flame combustibility efficiency. With a jet velocity of 49.6 ms −1 and a cross-wind speed of 5 ms −1 , changing the cross-wind angle ( α ) to 40° resulted in a smaller angular displacement of the flame in the direction parallel (vertical) to the flow, a taller flame in the vertical direction, and a broader top width in the radial direction. The central flame area with the high temperature was increased gradually and the efficiency of the flame at the center to burn increased by 45.7 %.