Experimental Study On Dispersion And Explosion Characteristics Of Zirconium Hydride Winch

Due to the need to cut the fuel rod in the nuclear fuel reprocessing process,zirconium hydride dust will inevitably be produced in the cutting process.These dust will be winded,dispersed and suspended in the air under the action of air flow.If it meets a small energy ignition source,it will explode.It is necessary to have a deep understanding of the characteristics of zirconium hydride winch,suspension and explosion accidents caused by weak ignition.At present,the research on the rule of dust lifting and the explosion characteristics of zirconium hydride under shock wave is very rare.In this paper,transparent pressure resistant plexiglass pipe with inner diameter of 125 mm and steel pipe with visual window wre used to study the dispersion and explosion process of zirconium hydride winch by using high-speed camera technology,pressure and flame acquisition technology and PIV particle image velocimetry technology.The results are as follows:Through the experiment of dust deposition by shock wave in plexiglass tube,it is confirmed that Helms oscillation appears in the process of dust hoisting.The phenomenon and process of Helms oscillation are explained by using the reflection theory of shock wave.Using PIV particle image velocimetry technology,it is found that eddy current appears in the process of film breaking shock wave hoisting deposition of zirconium hydride,which consumes the energy of shock wave.At the same time,it is found that the velocity field is stratified in the initial stage of the flame movement when the film breaking combustion wave ignites the deposited zirconium hydride.Through the secondary explosion experiment of dust deposited by shock wave in steel pipe,it is found that the explosion of zirconium hydride is caused by the rupture of shock wave film.The influence factors of zirconium hydride particle size,zirconium hydride concentration and tube length were analyzed.The bend pipe disturbs the zirconium hydride explosion flame,intensifies the coupling effect between the precursor shock wave and the flame,and the pressure and velocity increase sharply.When the concentration of nitrogen and air increases to 5:1,the explosion of zirconium hydride will be completely inhibited.