Abstract: In order to analyze the anti-explosion capability of the explosion-proof box of the cable middle joint under the action of internal explosion, a numerical model of the cable middle joint with the explosion-proof box was established. The fluid-solid coupling method is used to simulate the explosion process of the typical structure of the explosion-proof box, and the influence of center radius ratios, end radius ratios, shapes, materials, and whether to fill sealant or not. The results show that the explosion center ring surface and both ends of the explosion-proof box shell are bearing the greatest impact, and should be enforced; the anti-explosion capability of the explosion-proof box increases a lot with the increase of the center radius ratio, and increases a little with the increase of end radius; the anti-explosion capability of the cylindrical explosion-proof box is better than stepped explosion-proof box under the same central radius; the aluminum-magnesium alloy explosion-proof box is blown up in the same simulation conditions, whose anti-explosion ability is worse than stainless steel; packing sealant helps a lot to the explosion-proof box, and the performance of filling polyurethane sealant is slightly better than that of filling epoxy sealant.

Key words: fire, cable middle joint, explosion-proof box, anti-explosion capability