水质工程用紫外光消毒器的CFD数值模拟

紫外光消毒法是一种重要的污水深度处理方法,消毒器内部辐射强度的分布情况、微生物的停留时间及其运动轨迹对灭菌效果起着至关重要的作用。本文首次在国内系统介绍了采用计算流体动力学(CFD)手段对紫外光消毒器进行数值模拟研究的理论基础和技术路线,指出辐射强度的计算和停留时间的确定是其中的关键。以特定结构的紫外光消毒器为对象,对其内部流场进行了模拟计算,讨论了挡板位置不同所引起的消毒器内部速度场的变化情况;应用离散坐标辐射模型(DO)对紫外光辐射强度分布进行了模拟,同时加入离散粒子模型(DPM)来模拟消毒器内微生物的停留时长和运动轨迹,为最终计算微生物所受紫外光辐射剂量奠定了坚实的基础。

CFD simulation of ultraviolet disinfection reactor used in water quality engineering

Ultraviolet disinfection(UVD) is an important method for the advanced wastewater treatment.The radiation intensity in the radiation field,the residence time and the trajectory information of microorganisms are the major factors affecting the inactivation.It is the first time in the domestic to introduce the theoretical foundation and technological route of the UV reactor by numerical simulation using computational fluid dynamics(CFD),among which the calculation of radiation intensity and the determination of residence time are the critical points.CFD simulations have been executed for the specific structure of a given UV reactor,the effects of different baffle locations on the internal velocity distribution are discussed.The DO(discrete ordinate) model is utilized to simulate the radiation intensity,as well as the DPM(discrete particle model) is adopted to achieve the microbial residence time and trajectory information.All these works have laid a solid foundation for the ultimate calculation of UV dose.