Abstract: The paper designs the smoke-sensing fire-extinguishing device for fire detection and extinguishing, aiming at the problems of low sensitivity of fire detection, low efficiency of fire extinguishing medium, and danger in pressure storage design of modular data center. Based on Mie scattering principle, active air sampling smoke detection technology is used for early fire detection. The optical simulation software is used to simulate the optical path of the detection chamber, and the structure of the detection anechoic chamber is optimized. A non-pressure-storing, clean and environment-friendly perfluorohexanone fire extinguishing device was invented. The device has multi-level early warning and alarm design. According to the test, the concentrations of initial, medium and advanced early warning of the device are 0.05 db/m, 0.11 db/m and 0.21 db/m respectively. The smoke sensitivity is class I, the average spraying time of fire extinguishing agent is 7.2 s, and the average extinguishing time is 11.2 s. It has high sensitivity and good fire extinguishing ability, which can ensure the safe operation of data center equipment.

Key words: modular data center; smoke detection; perfluorohexanone; optimal design