Abstract: In order to fill the gap in the research on the rapid flame detection systems for storage tanks, a composite tank flame detector based on ultraviolet and infrared was developed and modes were studied for arranging the detectors on the top of the tank. The flame propagation characteristics of alcohol and n-heptane were studied experimentally. The detector's performance parameters were determined according to the data on the flame spread speed obtained in the experiments. Modes for arranging the detectors in storage tanks were designed in terms of detecting angle, detecting distance and dimensions of tanks. The results show that the flame propagation speeds of alcohol and n-heptane are 2.2-2.4 m/s and 1.5-1.7 m/s respectively at normal temperature and pressure, and the flame propagation speeds are not affected by the oil pool scale and the liquid layer thickness, and the detector's performance parameters meet the requirements of tank fire rapid detection, and the four modes of arrangement are efficient and reliable.

Key words: flame spread speed, oil tank, flame detector, circuit design, performance testing, layout modes