Modeling and CFD simulation of industrial steam-assisted flare in threedimension mode of flare tip of low-pressure in South Pars refinery was performed in this thesis in order to investigate the combustion characteristics and environmental factors on its performance. To create the computational range geometry, all geometrical details of the flare, including gas seal equipment, the flame stabilization plane and the windshield, were considered. In this project, a hybrid computing network was used to create an optimal computing network. The governing models of the problem including hydrodynamic, heat transfer, combustion, radiation and turbulence, were developed with their simultaneous interaction in the commercial software of Ansys Fluent. The two- step equation turbulence model of k- Ɛ was used to simulate the behavior of turbulent fluid, and the finite rate eddy dissipation model was used for computing the rate of combustion reaction. Furthermore, for modeling the radiation, the P1 model was implemente. To predict soot and NOx formation, the two-steps models of thermal and pro‎mp‎t mechanisms and the mechanism of formation of NOx were employed, respectively. The validity of the developed computational model was eva‎luated and corroborated through a laboratory flare. Based on the developed computational model, hydrodynamic characteristics, temperature, concentration of gas emitted to the flare tip, combustion product, and efficiency, soot and NOx formation rates for an industrial scale were obtained in its whole computational range. The effects of displacement and amount of injected steam into flare on combustion efficiency, soot and NOx formation rate at different wind speeds in two modes of lateral and central steam injection were investigated. Based on the simulation results for both modes of the steam injection, upon increasing of wind speed, combustion efficiency decreases while increasing soot and NOx formations. Moreover, upon reduction of steam flow by 30%, there are better performance, higher combustion efficiency and lower soot formation in flare for the central steam injection mode in comparison the other mode. In case of increasing the steam flow by 30%, for the lateral steam injection mode, there are a better performance by lower soot formation, higher combustion efficiency and NOx formation

ارجمند مهرباني، يعقوب بهجت

محسن دوازده امامي

عليرضا خز علي، ايمان چيت ساز