China Safety Science Journal ›› 2026, Vol. 36 ›› Issue (7): 86-91.doi: 10.16265/j.cnki.issn1003-3033.2026.07.0237

• Safety Technology and Engineering • Previous Articles     Next Articles

Study on fire extinguishing performance of compressed air foam under variable pressure and fire source power

Guo Yi1,2(), Tan Tiantian1, Zhang Jiaqing1,**(), Wu Gexin3, Li Bo3   

  1. 1 State Grid Anhui Electric Power Research Institute, Anhui Provincial Key Laboratory of New Type Power Systems Fire Safety and Emergency Technology (State Grid Laboratory of Fire Protection for Transmission and Distribution Facilities), Hefei Anhui 230601, China
    2 State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei Anhui 230031, China
    3 Faculty of Engineering, China University of Geosciences (Wuhan), Wuhan Hubei 430074, China
  • Received:2026-02-05 Revised:2026-05-07 Online:2026-08-10 Published:2027-01-28
  • Contact: Zhang Jiaqing

Abstract:

To investigate the fire extinguishing performance of compressed air foam under different ambient pressures and fire source powers, a Computational Fluid Dynamics (CFD)-based numerical simulation was employed. A three-dimensional numerical model was developed and validated, and the foam discharge and combustion processes were analyzed. The extinguishment state was determined based on the CO2 mass fraction, fuel mass fraction, and reaction rate. Key parameters, including extinguishing time, foam coverage area, discharge distance, and fire temperature distribution, were analyzed, and an empirical correlation for foam extinguishing time applicable to different ambient pressures and fire source powers was established. The results show that within the ambient pressure range of 50-100 kPa, the extinguishing time for two fire source powers (13.85 and 31.84 MW) increase monotonically with increasing ambient pressure. The increase in pressure alters the foam structure and flow characteristics, weakening its spreading and fuel-surface sealing capacity, thereby prolonging the extinguishing process. The foam coverage area remains essentially equal to the oil pool area under all pressure conditions, stabilizing at approximately 10 and 26 m2, indicating that ambient pressure has a limited effect on coverage area. The foam discharge distance shows minor variation and remains around 2.7 m, suggesting negligible influence of ambient pressure. After extinguishment, the temperature distribution exhibits spatial non-uniformity: the temperature in regions initially covered by foam decreases rapidly, whereas higher temperatures persist on both sides of the oil pool due to delayed foam coverage, posing a risk of reignition and requiring further cooling.

Key words: ambient pressure, fire source power, compressed air foam, extinguishing time, coverage, spray distance, temperature distribution

CLC Number: