Study On Damage Effect And Protection Design Of Explosion-proof Junction Box Of High Voltage Cable

The expansion of power energy demand has led to an increase in the construction of highvoltage cables,and the intermediate connector of the cable is the weakest part of the breakdown explosion,therefore,it is of good application value to optimize the explosion-proof performance of the high-voltage cable explosion-proof junction box.This paper firstly analyzes and compares the relationship between arc explosion and explosive explosion in terms of generation,propagation and intensity of action based on arc blast wave,energy balance theory and explosive blast wave theory,it shows that the explosion of the intermediate joint is due to the huge energy released by the arc discharge,which is very similar to the explosion of explosives.Then,using the explicit dynamics software AUTODYN,on the basis of verifying the validity of the numerical calculation and determining the energy level of the explosion source of the cable intermediate joint,simulate the pressure change in the box and the dynamic response on the explosion-proof box shell of the explosion process,the results show: the explosion center torus,end section and head center are the weakest part of the shell,Strengthening the protection of the three places and connection between the head and end section is the key to achieve explosion protection;shell is subjected to the impact load and the displacement deformation to jointly control the stress state of the wall surface under internal explosion,plastic deformation occurs due to elastic deformation and final yielding under the leadership of tensile stress,under the dominance of tensile stress,from elastic deformation to yielding and finally plastic deformation occurs,when the deformation limit is reached,it will first crack on the outer surface,and finally form a shear-type fracture zone with a radial angle of about 45°.Finally,based on numerical simulation and sensitivity analysis,the dynamic response and overall shape of the shell at critical locations(the explosion center torus and head center)are used as criteria,the effects of explosion energy,thickness,inclination angle,body length,head shape and leakage layout on the shell deformation were studied,It is important to determine the appropriate level of energy for the explosion-proof design;increasing the thickness within the appropriate range can improve the anti-explosion;the smaller the inclination angle,the better the protection of the head,and increase the body length is not great,the explosion resistance of the spherical head is significantly better than that of the flat head.The opening on the explosion center torus of the shell can effectively release energy and weaken deformation,but the expansion of the leakage area only significantly weakens deformation of shell near the opening;increase number of openings will exacerbate the deformation on the explosion center torus,but at the same time allows the shock wave to have more chance of venting outwards as it travels to both ends,and reducing the pressure on the head;In addition,the possibility of axial fracture of the leak boundary must be considered,and measures should be taken to increase the strength of the axial connection between the two openings.