(1) Fix a fine water mist nozzle at a vertical position at the center of the roof, ensuring the distance Lp between the nozzle and the oil pan is adjustable (since the nozzle position is fixed in the laboratory, this can be achieved by elevating the oil pan). Place the oil pan on the floor of the room, using the nozzle position as a reference point; the coordinates of the oil pan relative to the nozzle can be represented by the nozzle height Lp and the radial distance R.
(2) Kerosene is used as the combustion substance in the experiment. The combustion model consists of a circular oil pan filled with kerosene. The oil pan is made of steel plate, with a diameter of 300 mm, a wall thickness of 2.0–3.0 mm, a depth of not less than 200 mm, and an oil layer thickness of approximately 30 mm.
(3) Place thermocouple 1 at a height of 150 mm directly above the oil pan, and then place three thermocouples (thermocouples 2 to 4) vertically at 150 mm intervals. The spacing between these thermocouples is adjustable (the number of thermocouples can be increased or decreased as needed), and they are fixed on a movable bracket. When the position of the oil pan is changed, the support moves accordingly to ensure that the four thermocouples are always directly above the oil pan.
(4) In each experiment, the temperature acquisition system is first activated, then the oil pan is ignited. When the temperature reading of thermocouple No. 1, 150 mm away from the oil pan, reaches 500 °C, fine water mist is released to extinguish the fire. After the flame is extinguished, spraying continues for 10 seconds to cool and reduce dust, then spraying is stopped and smoke and ventilation are initiated. If the fine water mist spraying time exceeds 60 seconds and still cannot extinguish the flame, spraying is stopped, doors and windows are opened, and the smoke exhaust fan is activated for ventilation. Residual flames are then manually extinguished.
