基于AMESim的SCR脱硝系统仿真分析研究

Research on SCR Denitration System Simulation Analysis Based on AMESim

针对热电厂锅炉烟气脱硝系统运行过程中变工况和温度不均匀对脱硝效率影响的问题,为了对脱硝系统的特性进行研究,使用AMESim软件建立了基于物理机理的模型,完成了SCR系统不同操作工况的仿真。通过分析喷氨量、反应温度和温度均匀性等因素,得到结果:喷氨量和反应温度均对脱硝效果有重要的影响,其中额定工况下氨氮比为1.04时可达到较好的脱硝效果和较低的氨逃逸率;运行中烟气温度在70℃范围内变化,脱硝效果可以满足环保要求,且烟气温度高更有利于脱硝效率提升;保温层的厚度160 mm时,SCR反应器垂直于烟气流动方向的温度分布均匀。通过仿真分析,为脱硝系统的设计和控制提供了依据。

A selective catalytic reduction process simulation model based on physical mechanism is established in AMESim,a commercial process simulation package.The model is suitable for the denitration process of flue gas in thermal power plants to deal with the problem of variable working conditions and temperature unevenness which have influence on denitration efficiency.Using the model to study its characteristics,the simulation is employed such as sensitivity analysis of ammonia injection,reaction temperature and temperature uniformity.The simulation results show that both the ammonia injection amount and the reaction temperature have important effects on the denitration efficiency.When the amount of ammonia sprayed is 1.04 times of the ideal amount,higher denitration efficiency and lower ammonia escape rate can be achieved.The temperature rise is beneficial to the denitration process.During the operation,the flue gas temperature rises within 70℃,and the denitration effect can meet the environmental regulation requirements.When the thickness of the insulation layer is 160 mm,the temperature inside the SCR reactor is evenly distributed perpendicular to the direction of flue gas flow.The simulation analysis provides the basis for the design and control of denitration system.