Research on the Re-Entrainment Mechanism in Corrugated Plate Driers in the Nuclear Field

Abstract The corrugated plate dryer is an important steam-water separation equipment in the secondary loop of the mainstream third-generation nuclear power plant in the field of nuclear engineering. The important parameter indicator of the corrugated plate dryer is its separation efficiency. The Re-entrainment phenomenon is a key issue that prevents further improvement of the separation efficiency of the corrugated plate. Its connotation is the phenomenon of secondary liquid droplets being carried by the airflow, leading to a decrease in the efficiency of steam water separation. Starting from the mechanism of Re-entrainment, this article analyzes the fluctuation of the liquid film inside the corrugated plate, the occurrence process of liquid film rupture, and the location and size of secondary liquid droplets generated by liquid film rupture. Based on the establishment of a two-dimensional curve coordinate system at the corner position of the corrugated plate, the force analysis of a thin liquid film with a width of dr and a curvature radius of r in the radial and axial directions is also conducted. Define dimensionless parameters to obtain the order of each item in the liquid film control equation, and then ignore the higher order, ultimately obtaining the liquid film rupture model. Based on the above liquid film rupture model, high-precision three-dimensional calculation of the waveform plate was achieved, thereby achieving accurate calculation of the position of secondary droplet generation. The results indicate that there are obvious nonlinear characteristics in the location and size of the liquid film rupture inside the corrugated plate. The size of secondary droplets is mostly in the millimeter range. The above model provides important technical support for the elimination of Re-entrainment phenomenon and provides important reference for the design of corrugated plate dryers in nuclear power plants and nuclear power plants.