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清华大学学报(自然科学版)  2022, Vol. 62 Issue (6): 1023-1030    DOI: 10.16511/j.cnki.qhdxxb.2022.22.035
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不同外部辐射热流下小尺寸原木燃烧特性实验研究
胡皓玮, 祁桢尧, 时敬军, 纪杰
中国科学技术大学 火灾科学国家重点实验室, 合肥 230026
Experimental investigation of the burning behavior of small logs with various external radiative heat fluxes
HU Haowei, QI Zhenyao, SHI Jingjun, JI Jie
State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei 230026, China
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摘要 木材因其优异的隔热性能、力学强度和观赏价值而被广泛应用于建材、家具和工艺品中。作为一种可燃材料,木材的燃烧过程会经历热解、点燃、炭化与开裂。目前对于木材燃烧特性的研究,样本通常选用均质的人造板材或避开缺陷的原木。但实际情况下,不同树种结构各异,制备而成的原木板表面的纹理分布不均匀,同时原木中还存在木节等结构缺陷,这些因素都可能影响原木板材的燃烧过程。该文在火焰蔓延量热仪下开展小尺寸原木板材燃烧实验,使用3种树种(辐射松、白松、杉木)的原木,比较了不同外部辐射热流下原木的燃烧特性,获得了不同树种的典型燃烧行为、热释放速率曲线和点燃特性。结果表明,不同树种、不同纹理、结构缺陷(木节)会影响原木的燃烧行为。随着外部辐射热流的增加,原木的点燃时间缩短,热释放速率峰值增加。在该文实验工况范围内,外部辐射热流15 kW/m2时原木点燃时间的重复性差异最大约35%,高于均质人造板材,体现了原木结构非均质性对其燃烧特性的影响,但这一差异随外部辐射热流的增加而减小。对于同一树种,疏、密纹理样本的燃烧特性存在差异,辐射松疏、密纹理原木点燃时间差值最大可达500 s以上,且平行于纹理方向上的炭化速率高于垂直于纹理方向上的。杉木中含有大量木节,低外部辐射热流条件下木节的存在会导致点燃时间缩短、热释放速率峰值增加。
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胡皓玮
祁桢尧
时敬军
纪杰
关键词 木材燃烧原木纹理木节炭化    
Abstract:Wood is widely used in building materials, furniture and handicrafts due to its excellent thermal insulation properties, mechanical strength and ornamental value. However, wood is a combustible material that undergoes pyrolysis, ignition, charring and cracking. Most current studies on the burning characteristics of wood have used relatively homogeneous artificial boards or logs without defects. However, in practical applications, wood structures vary among different species, the wood surface grain is not uniform, and there are many structural defects in the logs, such as knots. These factors cause the wood burning characteristics to differ significantly from that of a homogeneous board. This study experimentally investigated the burning of small logs made of white pine, radiata pine and Chinese fir. The burning behaviors were compared with different external radiative fluxes with measurements of the burning phenomenon, heat release rate, and ignition characteristics. The results show that the wood species, the grains and the defects (knots) all affect the wood burning characteristics. Increasing the external heat flux reduces the ignition time and increases the peak heat release rate. In the range of operating conditions in this paper, the difference of the log ignition time at the external radiative heat flux of 15 kW/m2 in the repeated tests is about 35%, which is higher than that of the homogeneous artificial wood. This trend indicates the effect of structural heterogeneity on the combustion characteristics of logs, but this difference decreases with the increase of the external radiative heat flux. For the same tree species, the combustion characteristics of sparse and dense grain samples are different. The highest ignition time difference is more than 500 s, and the charring rate is higher in the direction parallel to the grain than in the direction perpendicular to the grain. The Chinese fir contains a large number of knots, which can reduce the ignition time and increase the peak heat release rate at the low external radiative heat flux.
Key wordswood burning    log    grain    knot    charring
收稿日期: 2022-01-15      出版日期: 2022-05-06
基金资助:国家重点研发计划项目(2020YFC1522800)
通讯作者: 纪杰,研究员,E-mail:jijie232@ustc.edu.cn      E-mail: jijie232@ustc.edu.cn
作者简介: 胡皓玮(1994-),女,博士后。
引用本文:   
胡皓玮, 祁桢尧, 时敬军, 纪杰. 不同外部辐射热流下小尺寸原木燃烧特性实验研究[J]. 清华大学学报(自然科学版), 2022, 62(6): 1023-1030.
HU Haowei, QI Zhenyao, SHI Jingjun, JI Jie. Experimental investigation of the burning behavior of small logs with various external radiative heat fluxes. Journal of Tsinghua University(Science and Technology), 2022, 62(6): 1023-1030.
链接本文:  
http://jst.tsinghuajournals.com/CN/10.16511/j.cnki.qhdxxb.2022.22.035  或          http://jst.tsinghuajournals.com/CN/Y2022/V62/I6/1023
  
  
  
  
  
  
  
  
  
  
  
[1] DINWOODIE J M. Timber:Its nature and behaviour[M]. London, UK:E & FN Spon, 2000.
[2] ROSS R L. Wood handbook:Wood as an engineering material[R]. General Technical Report FPL-GTR-190. Madison, USA:Forest Products Laboratory, USDA Forest Service, 2010.
[3] 王苏盼, 黄鑫炎, 李开源. 木质材料火灾研究:前沿与展望[J]. 工程热物理学报, 2021, 42(10):2700-2719. WANG S P, HUANG X Y, LI K Y. A review of fire research on wood materials:Research advances and prospects[J]. Journal of Engineering Thermophysics, 2021, 42(10):2700-2719. (in Chinese)
[4] DINWOODIE J M. Timber:A review of the structure- mechanical property relationship[J]. Journal of Microscopy, 1975, 104(1):3-32.
[5] REGAN J W. Heat release rate characterization of NFPA 1403 compliant training fuels[J]. Fire Technology, 2021, 57(4):1847-1867.
[6] MAAKE T, ASANTE J, MWAKIKUNGA B. Fire performance properties of commonly used South African hardwood[J]. Journal of Fire Sciences, 2020, 38(5):415-432.
[7] HARADA T. Time to ignition, heat release rate and fire endurance time of wood in cone calorimeter test[J]. Fire and Materials, 2001, 25(4):161-167.
[8] HAO H L, CHOW C L, LAU D. Effect of heat flux on combustion of different wood species[J]. Fuel, 2020, 278:118325.
[9] XU Q F, CHEN L Z, HARRIES K A, et al. Combustion and charring properties of five common constructional wood species from cone calorimeter tests[J]. Construction and Building Materials, 2015, 96:416-427.
[10] WANG S P, DING P F, LIN S R, et al. Deformation of wood slice in fire:Interactions between heterogeneous chemistry and thermomechanical stress[J]. Proceedings of the Combustion Institute, 2021, 38(3):5081-5090.
[11] ISHIKAWA T, MIZUNO K, KAJIYA T, et al. Structural decay and flame retardancy of wood as a natural polymer[J]. Combustion Science and Technology, 2005, 177(4):819-842.
[12] FERRANTELLI A, BAROUDI D, KHAKALO S, et al. Thermomechanical surface instability at the origin of surface fissure patterns on heated circular MDF samples[J]. Fire and Materials, 2019, 43(6):707-716.
[13] LI K Y, HOSTIKKA S, DAI P, et al. Charring shrinkage and cracking of fir during pyrolysis in an inert atmosphere and at different ambient pressures[J]. Proceedings of the Combustion Institute, 2017, 36(2):3185-3194.
[14] LI K Y, MOUSAVI M, HOSTIKKA S. Char cracking of medium density fibreboard due to thermal shock effect induced pyrolysis shrinkage[J]. Fire Safety Journal, 2017, 91:165-173.
[15] LYONS P R A, WEBER R O. Geometrical effects on flame spread rate for wildland fine fuels[J]. Combustion Science and Technology, 1993, 89(1-4):153-165.
[16] DAHANAYAKE K C, YANG Y Z, WAN Y, et al. Study on the fire growth in underground green corridors[J]. Building Simulation, 2020, 13(3):627-635.
[17] HASBURGH L E, CRAFT S T, VAN ZEELAND I, et al. Relative humidity versus moisture content relationship for several commercial wood species and its potential effect on flame spread[J]. Fire and Materials, 2019, 43(4):365-372.
[18] FRANGI A, FONTANA M. Charring rates and temperature profiles of wood sections[J]. Fire and Materials, 2003, 27(2):91-102.
[19] SHIELDS T J, SILCOCK G W, MURRAY J J. The effects of geometry and ignition mode on ignition times obtained using a cone calorimeter and ISO ignitability apparatus[J]. Fire and Materials, 1993, 17(1):25-32.
[20] BARTLETT A I, HADDEN R M, BISBY L A. A review of factors affecting the burning behaviour of wood for application to tall timber construction[J]. Fire Technology, 2019, 55(1):1-49.
[21] TSAI K C. Orientation effect on cone calorimeter test results to assess fire hazard of materials[J]. Journal of Hazardous Materials, 2009, 172(2-3):763-772.
[22] DRYSDALE D. An introduction to fire dynamics[M]. 3rd ed. Chichester, UK:John Wiley & Sons, 2011.
[23] QUINTIERE J G. Fundamentals of fire phenomena[M].Chichester, UK:John Wiley & Sons, 2006.
[24] SULEIMAN B M, LARFELDT J, LECKNER B, et al. Thermal conductivity and diffusivity of wood[J]. Wood Science and Technology, 1999, 33:465-473.
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