选择性催化还原脱硝装置内部磨损数值模拟

Numerical simulation of inner abrasion in a selective catalytic reduction deNO_x device

为解决选择性催化还原(SCR)脱硝装置在运行中出现的喷氨喷嘴和催化剂层严重磨损问题,采用GAMBIT软件模拟脱硝装置内部流场的速度分布,并通过现场冷态试验验证模型的有效性。模拟结果表明:SCR脱硝装置入口处烟道存在上下或左右倾斜,整流格栅和转向弯头处存在高度差,使得烟气经过整流格栅后进入催化剂层的速度分布不均匀,导致喷氨喷嘴和催化剂层磨损;本文在数值模拟中改变引起流场分布不均的结构,能够解决其所造成的脱硝装置磨损问题;模拟结果与实际磨损状况一致,说明本文所用数值模型能准确模拟脱硝装置速度分布。

To solve the problem of severe abrasion of the ammonia injection spray nozzle and catalyst layer in selective catalytic reduction（SCR）equipment,the velocity distribution of the flow field in the internal flow field was simulated using GAMBIT software.The applied simulation model was verified through field cold test.The results show that the SCR denitration device has a high degree of difference between the top and bottom of the flue gas entrance,the rectifier grid and the steering elbow,which makes the gas flow through the rectifier grid into the catalyst layer.In the numerical simulation,the structure of the flow field distribution is changed,which can solve the abrasion problem of denitration device caused by the uneven distribution of the flow field.The numerical model can accurately simulate the velocity field distribution in the SCR device.