Abstract: The cable shaft of a hydropower station is a vertical high-rise channel, up to 100 meters high, used for laying power supply cables or communication cables for a hydropower station. If it is not well sealed or not sealed, the fire will spread quickly along the cable shaft. Taking the cable shaft of a hydropower station as the research object and using FDS numerical simulation software, this paper studies the influence of four factors, including longitudinal distance of high pressure water mist nozzles, number of simultaneous starting floors, nozzle flow coefficient and spray angle, on the fire- extinguishing effect. The critical values of each factor are established to effectively play the role of fire extinguishing. The results can provide reference for the design of fire extinguishing system of cable shaft of hydropower station.

Key words: cable shaft, hydropower station, water mist fire extinguishing system, FDS