Numerical simulation of flue gas desulfurization reactor based on reaction kinetics

In order to optimize the flow field distribution of active calcium circulating flue gas desulfurization reactor, and to explore the influence of important parameters on the desulfurization efficiency, a reasonable CFD numerical simulation calculation scheme was selected, combined with dynamic bench experimental data and calculation fitting. The obtained kinetic model of the desulfurization reaction simulates the flow field and desulfurization reaction process in the desulfurization reactor with a rated treatment capacity of 40 000 m3/h. Firstly, the uneven distribution of the flow field appears in the simulation result of the original design reactor, and an optimization scheme is proposed. The distribution of velocity field, turbulence intensity field and static pressure field in the reactor before and after optimization was compared. Then through the numerical simulation of thermal state, the effects of three main process parameters of near adiabatic saturation temperature difference (AAST), humidi-fication water volume and solid-gas ratio on desulfurization efficiency were comprehensively investigated, and the simulation results were compared with the test results. The results show that the uneven distribution of particles caused by non-uniform feed is the main problem of the flow field. An optimization scheme for adding guide vanes in the reactor is proposed for solving the problem. By extending the turning flow field and enhancing turbulence, the flow field has been more uniformed and enhanced flow stability. AAST has an obvious influence on the desulfurization efficiency, the desulfurization efficiency increases with the decrease of AAST, the AAST increases by 15 ℃, and the desulfurization efficiency can be reduced by 33.5%, the optimal ASST is about 15 ℃; The humidification is also one of the main parameters affecting the desulfurization efficiency, the desulfurization efficiency increases with the increase of humidification water volume. Before the humidification water reaches 1 000 kg/h, the desulfurization efficiency increases rapidly, and the humidification water volume is 1 000~1 300 kg/h, the desulfurization efficiency growth rate is slowed down. When the humidification water volume rises to 1 300 kg/h, the measured desulfurization efficiency reaches a maximum of about 93%. The desulfurization efficiency increases with the increase of the solid-gas ratio, and the maximum desulfurization efficiency can be achieved about 25%. In addition, there is a good degree of fitting between the calculated result and measured result. © 2020, Editorial Office of Journal of China Coal Society. All right reserved.