Abstract: The Box-in reduction structure outside the transformer has hindered and blocked the external fire fighting and rescue, which seriously affects the effective fire fighting. The melting behavior of the new noise reduction board (Box-in) and the fire extinguishing process in converter substation were investigated experimentally. The influence of the breaking process of the new noise reduction plate on the fire extinguishing effect and the influence of high temperature hot oil fire on the pipeline of Box-in internal fixed fire extinguishing system were analyzed. The experimental results showed that the two new noise reduction plates could fuse and fall in the fire, which provided favorable conditions for the external fire operation of the Box-in noise reduction device. However, the fire extinguishing difficulty was still significantly greater than that of the unshielded fire. The high temperature of the fire process would lead to the obvious change of the direction of the fixed fire branch, which made the cover target dislocation and could not cover the target part.

Key words: melting behavior, fire extinguishing, noise reduction board, converter substation