撞击流技术研究进展及新型反应装置研发

Research Progress of Impinging Stream Technology and Development of New Reactors

在化学生产和石油化工等多种过程工业中,都会涉及多项体系中相间热(质)传递,探求强化传递过程已成为研究的焦点和热点,撞击流作为一种有效强化相间传热传质、促进微观混合的新技术,在吸收、结晶、超细粉体制备等领域均展示出良好的应用前景。基于作者多年来在撞击流领域的经验积累和研究成果,对撞击流技术的研究进展及新型反应装置研发进行了综述。借助LDA、PDA、PLIF等先进可视化测试技术,提取不同结构布置形式下撞击流流场内部压力波动、瞬时和时均速度、浓度信号等丰富信息,获得关于流场的宏观压力、速度、浓度分布规律;同时准确把握流场内各物理参量在流体力学方程组中的作用,通过混沌分析、分形分析、小波变换以及希尔伯特–黄变换等非线性研究方法,识别信号的混沌与随机成分,计算出关联维、Kolmogorov熵、Lyapunov指数、Hurst指数等定量描述非线性特征参数,明确流场宏观运动特征、传热、传质以及反应效果的影响;另外,介绍了离析度IOS、平面混合均匀度U等指标,用于定量表征不同结构特性参数(喷嘴直径d、喷嘴间距L等)下撞击流反应(混合)器的混合、振荡特性研究现状,并确定利于混合的最佳工况,通过上述研究,不断完善复杂湍流体系理论;结合FLUENT数值模拟软件,实验与理论相互印证,为撞击流反应器结构的优化及新设备的研发提供指导性参数,基于此,作者先后自主研发出具有知识产权的多组同轴相向撞击流反应(混合)器、水平三向撞击流反应(混合)器等,并以双组分层式撞击流反应器为核心建立用于制备超细粉体工业规模示范装置,为撞击流技术在工业上的开发应用提供了一条新的思路;最后,指出探究与其他先进技术(超高压、超临界等)协同增效的复合型撞击流反应(混合)器,成为未来研究发展一大方向。

In various process industries such as chemical production and petrochemical industry,the interphase heat(mass)transfer in many systems is involved.The exploration of enhanced transfer process has become the focus and hot spot of research.As a new technology to effectively enhance the heat and mass transfer between phases and promote micro-mixing,impinging stream has shown good application prospects in the fields of absorption,crystallization and ultra-fine powder preparation and so on.Based on the author’s years of experience in the field of impinging stream and research results,the research progress of impinging stream technology and the development of new reactors were reviewed.Using LDA,PDA,PLIF and other advanced visual testing techniques,the rich information such as pressure fluctuation,instantaneous and timeaverage velocity and concentration signal in the impinging stream field under different structural arrangements were extracted,and the macroscopic pressure,velocity and concentration distribution of the flow field were obtained.At the same time,the role of each physical parameter in the fluid mechanics equations was accurately grasped.The chaotic analysis,fractal analysis,wavelet transform and Hilbert-Huang transform were used to identify the chaotic and random components of the signal,calculate the quantitative description of nonlinear characteristic parameters,such as correlation dimension,Kolmogorov entropy,Lyapunov exponent and Hurst exponent and clarify the macroscopic motion characteristics,heat transfer,mass transfer and reaction effects of flow field.In addition,the indicators such as separation degree IOS and plane mixing uniformity U were introduced to quantitatively characterize the mixing and oscillation characteristics of impinging stream mix-reactor under different structural characteristic parameters(nozzle diameter d,nozzle spacing L,etc.),and determine the best working conditions for mixing.Through the above research,the theory of complex turbulence system was constantly improved.Combined with FLUENT numerical simulation software,experiments and theories confirm each other,providing guiding parameters for the optimization of the structure of the impinging stream reactor and the development of new equipment.Based on this,the author has independently developed multiple sets of coaxial impinging mix-reactor and horizontal three-way impinging stream mix-reactor with intellectual property and establishing a two-component layer impinging stream reactor as the core to establish an industrial scale demonstration device for preparation of ultrafine powder,which provides a new idea for the development and application of impinging stream technology in industry.Finally,it was pointed out that the complex impinging stream mix-reactor that explores synergy with other advanced technologies(ultra-high pressure,supercritical,etc.)has become a major direction for future research and development.