Abstract: Based on analysis for the arrangement characteristics of Box-in noise reduction device of UHV converter transformer, fire risk and common fire extinguishing technology, the influence of Box-in noise reduction device on fire extinguishing and fire development of UHV converter transformer was explained.Combined with the series test results of new hot melt noise reduction materials, a new noise reduction design scheme integrating new firefighting modules, hot melt support plates, anti-falling nets and explosion vents was proposed. The effectiveness of the design was verified by full-scale tests. The test results showed that the new firefighting module and hot melt support plate can quickly and effectively fall off under fire conditions, and the falling time was less than 2 min. The firefighting module after falling off was small and fragmentary, and the firefighting medium was not blocked and interfered. The new noise reduction design scheme can provide favorable conditions for external fire extinguishing, and significantly reduce the damage that explosion shock may cause to the internal fixed fire extinguishing system. At the same time, the price rise of the new noise reduction design scheme due to the new added function was acceptable.

Key words: noise reduction device(Box-in), fire extinguishing effect, new noise reduction materials, improvement design, fusion performance