CO 포함 방산 배가스의 연소효율 향상을 위한 수치해석 연구

다국어 초록 (Multilingual Abstract)

Some off-gases from a steel making process contains high concentration of CO which requires to be removed by oxidation at the flare stack. One way to achieve this is to install oxy-combustion gas burner at the shield of the flare stack for ignition of the off-gas. Using computational fluid dynamics (CFD), this study investigates the influences of design and operation parameters for the flare stack including different levels of CO concentration in the off-gas, tilting and yawing of four oxy-combustion gas burners, wind speed, pre-mixing of natural gas. The off-gas was difficult to maintain the flame because of its low energy content and excessive cooling by large volume of entrained air despite the use of oxy-combustion burner for heat-up and ignition. The flame was maintained only when the CO concentration in the off-gas was over 25% at the quiescent air condition, which achieved 99.7% of CO removal. Adjusting the burner angle was helpful in increasing CO oxidation inside the shield but was not successful in keeping the flame above. Pre-mixing natural gas inside the stack also increased the level of CO oxidation but has a cost issue. The optimal condition for near-complete CO oxidation were determined from the combustion efficiency and safety of the flare stack.