The 112th Mechanical System Seminar (The 54th Hiroshima University ACE Seminar) 

Date:  4 Jun, 2019   16：00-18：00

Place:  Engineering A3-131 Lecture Room, Higashi-Hiroshima Campus, Hiroshima University  

Lecture: Dr. Yangkyun Kim
Senior researcher, Fire Research Institute, Korea Institute of Construction and Building Technology, Korea

Title:  Development of fire suppression technology in subsea tunnel and drone technology for detection of hazardous gases

Abstract:
Numerical simulation on the water jet extinction system is carried out for systematical verification of its performance in subsea tunnel to enhance fire suppression performance. Numerical model applied is 2D Eulerian multiphase model, and its results is validated with the equation of motion and real-scale experiment. Simulation results show that volume fraction of water at all nozzle outlet pressures was less than 0.5. Also, water volume fraction on the ground of tunnel is increased according to an increase in jet discharge pressure in case of 0o of jet inclination angle, while water volume fraction on the ground of tunnel is decreased with an increase in jet discharge pressure in case of 5o and 11o of jet inclination angle. Gas detection test is carried out in open space through advanced open path infrared sensor (TOR sensor). In this study, chemometric method is applied to reduce interference in open space. Also, pyroelectric sensors and extra infrared lamps are applied to reduce its weight and size. The test is performed to detect gas concentration in 10 m with TOR sensor first in confined space, and real time gas detection test was successfully done eventually. Result shows that more than 0.9 correlation between supplied concentration and detected concentration by sensor. Eventually, real-time gas concentration in ppm is displayed on the geographical map to monitor gas safety.