制氢产物颗粒沉降过程特性的PIV试验研究

Experimental Study on the Characteristics of Particle Sedimentation Process by PIV in Hydrogen Production

针对实时投料式铝水制氢器中固相产物颗粒在液相工质中的沉降过程,进行冷态模拟试验研究,采用PIV系统对沉降过程进行拍摄观察,获得不同尺度颗粒的沉降过程特性,以及产物颗粒的不同尺度大小对沉降过程的影响规律。试验发现,松散状产物中,小尺度颗粒扩散速度较快,达到稳定状态(悬浮)的时间更短;团聚状产物中,小尺度状颗粒更容易随沉降过程发生逸散,较大尺度颗粒更容易沉降并离开液面。无论产物颗粒尺度大小,均能有效扩散至液相工质中,保证实时制氢反应的连续性和充分性。通过冷态试验,为掌握实时投料式制氢反应器内的产物沉降过程特性以及制氢反应器的投料方案设计,提供试验支撑。

A cold simulation experiment was carried out to study the sedimentation process of micro particles of solid products in liquid working medium in real-time feeding Aluminum-Water Hydrogen Generator.The settling process was photographed and observed by PIV(particle image velocimetry)system,and the characteristics of settling process of different sizes of particles and the influence of different sizes of product particles on the settling process were obtained.It is found that in the loose products,the diffusion rate of the small-scale particles is faster and the time to reach the steady state(suspension)is shorter;in the agglomerated products,the small-scale particles are more likely to escape with the settling process,and the larger-scale particles are easier to settle and leave the liquid surface.Regardless of the particle size of the product,it can be effectively diffused into the liquid working medium to ensure the continuity and adequacy of the real-time hydrogen production reaction.The cold state test provides experimental support for mastering the product sedimentation process in the real-time feed hydrogen production reactor and the design of feeding scheme for hydrogen production reactor.