Fire Safety Science Digital Archive

Experiments are described with a small compartment supplied through a large burner with town gas fuel. Above a critical fuel flow the heat transfer decreased with increasing flow. One reason for this was that the rate of heat release within the compartment depended directly on the rate of flow of air into the compartment; the rate of air inflow fell as fuel flow was increased, the total flow of gases out of the compartment increasing slightly, so that the flame temperature and heat transfer fell with increasing fuel flow. The other reason was due to the change in the distribution of the flame within the compartment. Measurements of the convective and radiative components of heat transfer, of flame and wall radiation, and of the heat balance of the compartment are reported and discussed. The measurements are in broad agreement with calculations based on a very simple theoretical model, which in principle can extend the results of these and similar experiments to other scales, fuels and wall materials.