بررسي تاثير تغيير دبي بر روي چگونگي عملكرد فلر با استفاده از مدلسازي به كمك ديناميك سيالات محاسباتي( CFD )

Investigating the Effect of Flow Rate Changes on Flare Performance Using Computational Fluid Dynamics Modeling(CFD

ديناميك سيلات محاسباتي (CFD ) ابزار عددي مناسبي براي حل معادلات پيچيده جريان سيال، انتقال حرارت و واكنش شيميايي مانند مساله فلر است. در اين تحقيق تاثير تغيير دبي بر روي چگونگي عملكرد فلر يكي از پالايشگاههاي نفت ايران در محدوده دبي واقعي 4000 پوند در ساعت با استفاده از مدلسازي به كمك CFD با نرم افزار انسيس فلوئنت ورژن 16.0 مورد مطالعه قرار گرفته است و همچنين هندسه و مش بندي سيستم توسط نرم افزار گمبيت 2.4.6 انجام شده است تا اثر تغييرات دبي گازهاي خروجي روي دماي شعله، طول شعله، پروفايل غلظت گونه هاي حاصل از احتراق و الگوي جريان آشفته در شعله مورد بررسي قرار گيرد. محاسبات به صورت دو بعدي با شرط تقارن محوري مي‌باشد كه از مدل اغتشاش k-ε استاندارد، مدل احتراق Non-Premixed Combustion، الگوريتم SIMPLE بر پايه فشار و حالت پايا استفاده شده و همچنين از اثرات باد صرف نظر شده است

Computational Fluid Dynamics (CFD) is a good numerical tools to solve complicated equations like fluid flows, heat transfer and chemical reactions such as flares issue. In this study, the effect of a changes in the flow rate on flare performance of one of Iran's oil refineries in actual mass flowrate range of 4,000 pounds per hour was calculated using CFD modeling, with Ansys Fluent software 16.0. Also its geometry and mesh designing were carried out by Gambit software 2.4.6. To investigate the effect of changes in flow rate on the flame temperature, flame length, profile of the concentration of combustion species and the turbulent stream pattern in the flame The related calculations are 2D in terms of axis symmetry in which the turbulence was modeled by standard k-ε, Non Premixed Combustion models, Simple Algorithm based on basic pressure and steady state condition were applied and also neglected the effects of the wind. By aid of independant variables from mesh, for actual mass flow ranges, we chose 68700 cells. The simulation results showed that although by changing the mass flow rate, in the range of 4000 pounds per hour does not change the maximum flame temperature. But changes the altitude that happens in this temperature. The length of flame varied in following situation, real mass flow was 14.9 meter which by %10 changes in mass flow, the length displaced 0.66 meter. Therefore, the rate of k (turbulence kinetic energy), ε (loss kinetic energy) increased by increasing the mass flow rate. The distribution of hydrogen and methane constituents in the range of the flame is equal to 1% molar and, with increasing massflow rate both distribution widespread and range of distribution of water and carbon dioxide is 5 and 10%, respectively both Concentrations increased by increasing the mass flow rate.