昆明地区15种常见木本植物活枝的燃烧性

为分析比较不同植物活枝的燃烧性,在森林防火戒严期内,对昆明地区15种常见木本植物中小径级的活枝进行了热辐射引燃试验,对小径级的活枝进行了氧指数试验。在测定样品直径、含水率、引燃时间、有焰燃烧时间、试验过程中烟气温度和质量损失变化过程等基础上,提出并计算了表征活枝燃烧性能的综合燃烧特性参数S,根据该参数对15种植物中小径级活枝的燃烧性能进行了排序。结果表明,15种植物小径级的活枝均具有较强的阻燃性,燃烧性能顺序为:云南松<野八角<华山松<滇青冈<地盘松<云南樟<厚皮香<大白花杜鹃<炮状花杜鹃<云南含笑<小白花杜鹃<南烛<光叶石栎<元江栲<云南野山茶。根据氧指数及试验现象将15种植物的小径级活枝分为3类,其中难燃类4种(大白花杜鹃、野八角、厚皮香、南烛)、可燃类7种(云南含笑、云南松、地盘松、华山松、滇青冈、云南樟、云南野山茶)、较易燃类4种(小白花杜鹃、炮状花杜鹃、光叶石栎、元江栲)。分析了造成2种试验结果差异的主要原因。

Combustion characteristics of live branches of 15 common woody plant species in Kunming, Yunnan Province

To understand the live branches combustion characteristics of 15 common native woody plant species in Kunming, a thermal radiation ignition experiment with small and medium sizes branches and an oxygen index experiment with small size branches were conducted during peak forest-fire season. Based on the analysis of the sample’s diameter, moisture content, time to ignition, quenching time of flaming combustion, smoking temperature, and weight loss, an integrated combustion parameter (S) reflecting the combustion characteristics was proposed. According to the calculated S, the combustion order of the test tree species was Pinus yunnanensis < Illicium simonsii < Pinus armandii < Cyclobalanopsis glaucoides < Pinus yunnanensis var. pygmaea < Cinnamomum glanduliferum < Ternstroemia gymnanthera < Rhododendron decorum < Rhododendron spinuliferum < Michelia yunnanensis < Rhododendron siderophyllum < Lyonia ovalifolia < Lithoca mairei < Castanopsis orthacantha < Camellia pitardii. The oxygen index experiment indicated that the small size live branches of the 15 tree species all had obvious flame-retardant characteristics, of which, 4 (R. decorum, I. simonsii, T. gymnanthera, and L. ovalifolia) were difficultly inflammable, 7 (M. yunnanensis, P. yunnanensis, P. yunnanensis var. pygmaea, P. armandii, C. glaucoides, C. glanduliferum, and C. pitardii) were combustible, and 4 (R. siderophyllum, R. spinuliferum, L. mairei, and C. orthacantha) were inflammable. The reasons for the difference between the classifications derived by the two experiments were analyzed.