Initial fuel temperature effects on burning rate of pool fire

Area of Science:

• Fire Science
• Combustion Science

Background:

• Understanding n-heptane pool fires is crucial for fire safety and risk assessment.
• Initial fuel temperature is a key parameter influencing fire dynamics.

Purpose of the Study:

• To experimentally investigate the effect of initial fuel temperature on n-heptane pool fire burning behavior.
• To analyze the impact on burning rate, temperature distribution, and combustion stages.

Main Methods:

• Experiments conducted in a large test hall at the State Key Laboratory of Fire Science (SKLFS).
• Utilized circular pool fires with diameters of 100mm, 141mm, and 200mm.
• Varied initial fuel temperatures from 290 K to 363 K, recording burning rate and temperature data.

Main Results:

• Burning rate exhibited five stages: initial development, steady burning, transition, bulk boiling burning, and decay.
• Steady burning rate was largely independent of initial fuel temperature.
• Bulk boiling burning rate increased with initial fuel temperature, which also decreased the duration of the steady burning stage.
• Approaching boiling point eliminated the steady burning stage, leading directly to transition.

Conclusions:

• Initial fuel temperature is a critical factor, particularly influencing the bulk boiling stage of n-heptane pool fires.
• Higher initial temperatures lead to intensified burning and altered combustion phase durations.
• The study observed a boiling zone, with thickness increasing during bulk boiling phenomena.