Effectiveness of aviation kerosene pool fire suppression by water mist in a cargo compartment with low-pressure environment
ZHU Pei1, LUO Shengfeng2, LIU Quanyi3, SHAO Quan1, YANG Rui2
1. Civil Aviation College, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China; 2. Department of Engineering Physics, Tsinghua University, Beijing 100084, China; 3. College of Civil Aviation Safety Engineering, Civil Aviation Flight University of China, Guanghan 618307, China
Abstract：The low-pressure environments during flights of civil aircraft complicate the fire control and safety in cargo compartments. This study analyzed the effectiveness of large aviation kerosene surface pool fire suppression by water mist in a full-scale simulated cargo compartmentwith a low-pressure environment. The results show that without the water mist, the mass loss rate, flame temperature and radiant heat flux of the pool fire decreasewith decreasing ambient pressure, while the flame height increases.At an initial ambient pressure of 76 kPa, the compartment pressure increases rapidly after ignition, reaching an overpressure of 16.7 kPa, which increases the risk of failure of the cabin structure and ventilation system. With a water mist, the mist droplet size and the burning rate decrease with decreasing ambient pressure and the fire extinguishing time is significantly shortened, but the large firesare difficult to extinguish quickly due to the limited spray flux. In addition, the spray reduces the compartment temperature and radiant heat flux,such as a maximum temperature drop of 150℃ near the ceiling above the flame for an initial ambient pressure of 76 kPa.
朱培, 罗圣峰, 刘全义, 邵荃, 杨锐. 货舱低压环境下细水雾抑灭航空煤油池火有效性[J]. 清华大学学报（自然科学版）, 2022, 62(1): 21-32.
ZHU Pei, LUO Shengfeng, LIU Quanyi, SHAO Quan, YANG Rui. Effectiveness of aviation kerosene pool fire suppression by water mist in a cargo compartment with low-pressure environment. Journal of Tsinghua University(Science and Technology), 2022, 62(1): 21-32.
 CRAIG P L. "Environmental Control Systems" in the encyclopedia of aerospace engineering[M]. Hoboken, NJ:John Wiley & Sons, Ltd, 2010.  REINHARDT J W. Minimum performance standard for aircraft cargo compartment halon replacement fire suppression systems (2012 Update):DOT/FAA/TC-TN12/11[R]. Virginia:National Technical Information Services (NTIS), 2012.  LI Z H, HE Y P, ZHANG H, et al. Combustion characteristics of n-Heptane and wood crib fires at different altitudes[J]. Proceedings of the Combustion Institute, 2009, 32(2):2481-2488.  ZARZECKI M, QUINTIERE J G, LYON R E, et al. The effect of pressure and oxygen concentration on the combustion of PMMA[J]. Combustion and Flame, 2013, 160(8):1519-1530.  ZHOU Z H, WEI Y, LI H H, et al. Experimental analysis of low air pressure influences on fire plumes[J]. International Journal of Heat and Mass Transfer, 2014, 70:578-585.  TU R, ZENG Y, FANG J, et al. Low air pressure effects on burning rates of ethanol and n-heptane pool fires under various feedback mechanisms of heat[J]. Applied Thermal Engineering, 2016, 99:545-549.  HU L H. A review of physics and correlations of pool fire behaviour in wind and future challenges[J]. Fire Safety Journal, 2017, 91:41-55.  ZHU P, TAO Z X, LI C, et al. Experimental study on the burning rates of Ethanol-Gasoline blends pool fires under low ambient pressure[J]. Fuel, 2019, 252:304-315.  WANG J, PAN Y Y, LU S, et al. CO concentration decay profile and ceiling jet entrainment in aircraft cargo compartment fires at reduced pressures[J]. Applied Thermal Engineering, 2017, 110:772-778.  TAO Z X, YANG R, LI C, et al. Experimental study on liquid fire behavior at different effective ceiling heights in a full-size simulated cargo compartment[J]. Journal of Thermal Analysis and Calorimetry, 2018, 133(3):1617-1626.  刘全义, 孙中正, 吕志豪, 等. 不同压力条件下典型机舱材料燃烧特征的实验研究[J]. 清华大学学报(自然科学版), 2019,59(6), 59:432-437. LIU Q Y, SUN Z Z, LÜ Z H, et al. Experimental study of the burning characteristics of typical aircraft cabin materials at various pressures[J]. Journal of Tsinghua University (Science and Technology), 2019,59(6), 59:432-437. (in Chinese)  GUPTA M, PASI A, RAY A, et al. An experimental study of the effects of water mist characteristics on pool fire suppression[J]. Experimental Thermal and Fluid Science, 2013, 44:768-778.  SHRIGONDEKAR H, CHOWDHURY A, PRABHU S V. Characterization of a simplex water mist nozzle and its performance in extinguishing liquid pool fire[J]. Experimental Thermal and Fluid Science, 2018, 93:441-455.  LÜ D, TAN W, ZHU G R, et al. Gasoline fire extinguishing by 0.7 MPa water mist with multicomponent additives driven by CO2[J]. Process Safety and Environmental Protection, 2019, 129:168-175.  MARKER T R, REINHARDT J W. Water spray as a fire suppression agent for aircraft cargo compartment Fires:DOT/FAA/AR-TN01/1[R]. Virginia:National Technical Information Service (NTIS), 2001.  REINHARDT J W. The evaluation of water mist with and without nitrogen as an aircraft cargo compartment fire suppression system:DOT/FAA/AR-01/121[R]. Virginia:National Technical Information Service (NTIS), 2002.  吕志豪. 民机货舱细水雾雾场特性及抑灭火有效性研究[D]. 广汉:中国民用航空飞行学院, 2020. LÜ Z H. Study on flow field characteristics and fire suppression effectiveness of water mist in aircraft cargo compartment[D]. Guanghan:Civil Aviation Flight College of China, 2020. (in Chinese)  蔡昕. 高海拔低气压条件对细水雾灭火性能影响的实验研究[D]. 合肥:中国科学技术大学, 2009. CAI X. Experimental study on the effects of low ambient pressure conditions at high altitude on the fire suppression performance of water mist[D]. Hefei:University of Science and Technology of China, 2009. (in Chinese)  WANG X S, ZHU P, LI Y, et al. Effect of low ambient air pressure on spray characteristics of water mist[J]. Experimental Thermal and Fluid Science, 2015, 66:7-12.  ZHU P, WANG X S. Numerical study on the effects of ambient air pressure on water mist characteristics[J]. Energy Procedia, 2015, 66:169-172.  HUANG X, WANG X S, JIN X, et al. Fire protection of heritage structures:Use of a portable water mist system under high-altitude conditions[J]. Journal of Fire Sciences, 2007, 25(3):217-239.  CAI X, WANG X S, LIANG T S, et al. Experimental study on the effects of low ambient pressure conditions at high altitude on fire suppression with water mist[J]. Journal of Fire Sciences, 2010, 28(5):441-458.  MA Q J, WAN M S, SHAO J C, et al. Pool fire suppression performance by twin-fluid water mist under low pressures in an altitude chamber[J]. Process Safety Progress, 2021, 40(1):e12155.  刘全义, 孙强, 贺元骅. 低压环境下氮气-水低压双流体细水雾抑灭油池火[J]. 科学技术与工程, 2017, 17(33):363-368. LIU Q Y, SUN Q, HE Y H. Effect of low pressure environment on fire suppression of low-pressure N2-water twin-fluid water mist[J]. Science Technology and Engineering, 2017, 17(33):363-368. (in Chinese)  戴经天. 低压环境细水雾灭火有效性实验研究[D]. 广汉:中国民用航空飞行学院, 2019. DAI J T. Experimental study on the fire suppression effectiveness of water mist in low pressure environment[D]. Guanghan:Civil Aviation Flight College of China, 2019. (in Chinese)  Federal Aviation Administration, Cargo or baggage compartment smoke or fire detection systems.[EB/OL] (1998-02-17)[2021-04-27]. https://www.ecfr.gov/cgi-bin/text-idx?SID=82433bac09d19244b34b51ea6561c65a&mc=true&node=se14.1.25_1858&rgn=div8.  BABRAUSKAS V. "Heat release rates" in SFPE Handbook of Fire Protection Engineering[M]. 5th ed. New York:Springer, 2016.