摘要

In this paper, considering the possible narrow channel structure in actual firefighting, some marble narrow channels with different sizes are designed. The flame spread over n-butanol within narrow channels is conducted to reveal the inhibition behavior and heat transfer mechanism. The flame spread time and temperature distribution of subsurface flow are measured and the total heat flow and heat loss within the narrow channel are quantitatively calculated. The flame spread within the narrow channel is the pulsating manner of "jumping-retracting-jumping"; the narrow channel restricts or even completely suppresses the flame spread under the coupling effect of the cold wall effect and viscous force of the narrow channel; the spread time of narrow channel fire increases nearly linearly with the length of narrow channel and, and varies inversely with the width of narrow channel. When the heat loss from the sidewalls of the narrow channel accounts for more than 43.3% of the total heat flux, the heat loss completely suppresses the spread of the flame and the flame cannot pass through the narrow channel.