共查询到15条相似文献,搜索用时 127 毫秒
1.
2.
3.
《光谱学与光谱分析》2016,(10)
油罐池火燃烧污染强度大、范围广,航天遥感可成为实时动态监测油罐池火灾污染的新途径。航天遥感监测以目标光谱特性分析为基础,针对油料池火焰光谱特性研究不足的现状,通过构建全火焰红外测试系统,在室外开放空间条件下对多种油料及混合油料池火焰光谱,其他可燃物火焰的发射光谱进行了测试分析研究,光谱范围1~14μm。结果表明:92#汽油、95#汽油、0#柴油、航空煤油、润滑油池火焰的光谱曲线特征相似,在特定的波长处存在特征发射峰,在1.1,2.4,2.8及6.3μm附近存在H2O特征发射峰,在4.2及4.5μm附近存在CO2发射峰,在3.4μm处存在C—H伸缩振动发射峰,6.3μm后各光谱曲线无明显特征峰。92#汽油与0#柴油以不同比例混合的池火焰光谱与各油料池火焰光谱相比也无明显差别。92#汽油池火焰光谱与木柴及纸张火焰光谱相比,在3.4μm处存在特征发射峰;酒精火焰光谱虽然在3.4μm附近也有类似辐射发射,但辐射强度与4.5μm处CO2的辐射强度之比远低于92#汽油池火焰光谱在此两波段处辐射强度之比;蜂窝煤火焰光谱近似灰体辐射光谱。各燃料火焰光谱的差异主要由燃料的化学组成及燃烧反应机理的差异决定的。对92#汽油池火焰连续区、间歇区及烟气区的光谱特性进行了比较分析,结果表明3.4μm处的C—H伸缩振动峰只存在于连续区,证明了该发射峰是参与燃烧化学反应的油气产生的,该结果与油料池火燃烧反应机理吻合。实验结论对基于光谱特性分析的油料池火焰遥感识别具有重要借鉴意义。 相似文献
4.
油罐池火燃烧污染强度大、范围广,航天遥感可成为实时动态监测油罐池火灾污染的新途径。航天遥感监测以目标光谱特性分析为基础,针对油料池火焰光谱特性研究不足的现状,通过构建全火焰红外测试系统,在室外开放空间条件下对多种油料及混合油料池火焰光谱,其他可燃物火焰的发射光谱进行了测试分析研究,光谱范围1~14 μm。结果表明:92#汽油、95#汽油、0#柴油、航空煤油、润滑油池火焰的光谱曲线特征相似,在特定的波长处存在特征发射峰,在1.1,2.4,2.8及6.3 μm附近存在H2O特征发射峰,在4.2及4.5 μm附近存在CO2发射峰,在3.4 μm处存在C—H伸缩振动发射峰,6.3 μm后各光谱曲线无明显特征峰。92#汽油与0#柴油以不同比例混合的池火焰光谱与各油料池火焰光谱相比也无明显差别。92#汽油池火焰光谱与木柴及纸张火焰光谱相比,在3.4 μm处存在特征发射峰;酒精火焰光谱虽然在3.4 μm附近也有类似辐射发射,但辐射强度与4.5 μm处CO2的辐射强度之比远低于92#汽油池火焰光谱在此两波段处辐射强度之比;蜂窝煤火焰光谱近似灰体辐射光谱。各燃料火焰光谱的差异主要由燃料的化学组成及燃烧反应机理的差异决定的。对92#汽油池火焰连续区、间歇区及烟气区的光谱特性进行了比较分析,结果表明3.4 μm处的C—H伸缩振动峰只存在于连续区,证明了该发射峰是参与燃烧化学反应的油气产生的,该结果与油料池火燃烧反应机理吻合。实验结论对基于光谱特性分析的油料池火焰遥感识别具有重要借鉴意义。 相似文献
5.
CS2在当今化工等领域占据了重要地位,而CS2火灾污染事故危害性极大。通过研究CS2燃烧火焰光谱辐射以探究其火灾污染特性极为必要。搭建了CS2燃烧火焰光谱测试平台,采用黑体辐射源对VSR仪器进行了标定,通过多用途傅里叶变换(VSR)红外光谱辐射仪测试了5,10和20 cm三种燃烧尺度下CS2燃烧的火焰光谱,并通过热电偶测试了整个燃烧时间段内不同燃烧时刻下的火焰温度,以及在火焰上方安装了烟气分析仪对火焰中的燃烧产物浓度进行监测。测量了CS2整个燃烧时间段内火焰温度,以及不同燃烧时间、不同燃烧尺度下的火焰光谱、燃烧产物组分信息。测试结果表明,CS2火焰中主要含有高温SO2,CO2,CO气体和空气中卷入的H2O分子,并获取了特征污染产物SO2的浓度。由于现有光谱仪测量分辨率有限,室内实验测量的火焰尺度有限,为了能实现火灾在线监测需要建立一个火焰光谱辐射模型来反演CS2火灾时的污染物浓度相关信息。基于HITRAN数据库可知在2.7 μm附近为高温水蒸气的发射峰,4.2 μm附近特征峰为高温CO2气体的发射峰,4.7 μm附近有CO微弱的发射峰,在7.4 μm附近特征峰为高温SO2气体的发射峰,并获得了CS2燃烧时产生的SO2,CO2,CO和H2O气体在火焰燃烧相同温度下的吸收系数,通过计算得到了CS2燃烧时产生的SO2,CO2,CO和H2O混合气体的透过率与发射率,并结合气体辐射传输方程、气体吸收系数等方程,创建了CS2燃烧的火焰光谱辐射模型。利用该光谱辐射模型反演了不同燃烧时间下特征污染产物SO2的浓度,并与实验测得的数据进行了对比分析。结果表明,该模型精度高,可用于燃烧产物浓度的定量化反演,SO2分子含量在燃烧时间20,40,60和80 s时的反演精度分别是89.5%,82.5%,85.6%和86.5%。为遥感反演CS2型大尺度火灾中燃烧产物的浓度奠定基础。 相似文献
6.
7.
《光谱学与光谱分析》2020,(5)
近年来,化工领域对二硫化碳需求日益增多,而二硫化碳具有易燃易爆等特点。在生产过程中易发生火灾事故,危害性极大,易造成经济损失和人员伤亡。在火灾事故危害研究中,火焰光谱研究极有必要。因为火焰光谱中含有大量信息,包括火焰温度、燃烧组分、各个波段的热辐射强度等信息。以二硫化碳燃料为研究对象,搭建了火焰光谱测试平台,主要由VSR红外光谱仪、伸缩装置、燃烧器组成,测试了5 cm燃烧尺度下二硫化碳、苯乙烯、乙腈、乙酸乙酯燃料在1~14μm红外波段上燃烧火焰光谱,以及二硫化碳分别与苯乙烯、乙腈、乙酸乙酯三种不同燃料按照1∶1混合的火焰光谱,获取了二硫化碳火焰光谱特征波段,构建了二硫化碳火焰光谱特征库。在燃料单独燃烧火焰光谱研究中,二硫化碳燃料燃烧时火焰呈蓝色不发烟,其火焰光谱辐射主要来自于高温下SO_2, CO_2和H_2O三种分子辐射,其中SO_2特征峰为4.05, 7.4和8.51μm, CO_2特征峰为2.7和4.3μm, H_2O特征峰为2.5, 2.7和5.5~7μm,乙腈、乙酸乙酯燃料燃烧火焰光谱特征基本一致,火焰光谱辐射主要来自于高温下CO_2, H_2O分子辐射,苯乙烯火焰光谱辐射除了高温气体辐射外还有较强的炭黑辐射,炭黑辐射中心波长在7μm,温度大约在414 K。除此之外,苯乙烯燃料与其他三种化学品相比,在3.6μm波段处存在独有的C—H健伸缩振动峰。二硫化碳火焰燃烧产物与苯乙烯、乙腈、乙酸乙酯三种燃料相比具有独有的SO_2分子,其在4.05, 7.4和8.51μm处存在特有的特征峰,这些特征峰可作为航天探测识别其火灾依据之一;在燃料混合燃烧火焰光谱研究中,二硫化碳与苯乙烯、乙腈、乙酸乙酯三种燃料混合燃烧时,燃烧火焰光谱特征基本相似,火焰光谱辐射主要来自高温下CO_2, H_2O和SO_2分子辐射,实验表明,在混合燃烧时,二硫化碳的火焰光谱特征峰未被其他燃料的组分干扰,特征峰仍然明显。这一研究结果可为后续利用航天遥感探测技术探测识别二硫化碳火灾研究奠定基础。 相似文献
8.
油料池火焰内部分为不同燃烧区域,目前对油池火内部传热特性研究较少。针对油池火内部传热特性研究不足的现状,构建了红外火焰光谱测试系统,研究分析了92#汽油、95#汽油及润滑油池火焰红外光谱特性,对油池火焰不同燃烧区域的光谱信息进行了提取分析,结果表明:三种油料池火焰光谱特征相似,存在多个CO2,H2O及炭黑颗粒等燃烧产物的特征发射波段,3.4 μm处C—H伸缩振动峰明显;火焰烟气区主要光谱特征为4~4.5 μm波段范围内高温CO2发射峰,该区域火焰与空气换热剧烈,温度变化不稳定,火焰脉动频率较高;火焰间歇区的光谱特征是4~4.5 μm波段范围内高温CO2发射峰,与烟气区相比,火焰间歇区脉动频率相对较低;与烟气区及间歇区相比,火焰连续区燃烧较为稳定,该区域的光谱特征明显,在2.5~3 μm波段范围内炭黑粒子发射光谱强度较高,且在3.4 μm处存在C—H伸缩振动峰,表明油料池火焰光谱3.4 μm处的特征峰由高温油蒸汽产生。油池火焰不同燃烧区域光谱特征分析表明,油池火焰液态油表面的“富燃料层”吸收火焰传热,引起3.4 μm附近油蒸汽分子能级的改变。油池火焰不同燃烧区域发射光谱强度计算表明,火焰连续区的强度最大,其次为间歇区,火焰烟气区与空气对流强烈,测得的发射光谱强度最低。研究结果为火焰—油料传热模型的修正提供了参考。 相似文献
9.
10.
11.
通过对小尺度薄油池火燃烧特性进行实验研究,分析油池不同燃烧阶段的特点,探讨沸腾燃烧对油池燃烧特性的影响。测量了直径分别为0.10 m、0.14 m、0.20 m和0.30 m正庚烷油池火的燃烧速率以及温度分布随时间变化。分析燃烧过程中燃油液面温度和池壁温度的变化规律,研究池壁沸腾传热对油池沸腾燃烧的影响。结果表明:油池沸腾燃烧阶段的燃烧速率明显大于稳定燃烧阶段;燃油液面温度在油池燃烧初期迅速上升至沸点,随后基本保持不变;池壁温度达到并超过燃料的沸点,从而在油池壁面上发生沸腾现象,是油池发生沸腾燃烧的条件。 相似文献
12.
在10 m3的爆炸罐中对体积分数为8%的甲烷和75 g/m3煤尘的混合物进行了系统的燃烧爆炸实验。分别利用光测方法和压力方法得到了爆炸物的层流燃烧速度、火焰传播速度、火焰厚度、马克斯坦长度以及爆炸特征值的变化规律。结果表明,在常温常压下,当点火能为40 J时:利用光测法得到的8%甲烷与75 g/m3煤尘混合物的燃烧速度为0.437 m/s,而根据压力-时间关系得到的混合物燃烧速度为0.459 m/s,两者符合较好;用火焰厚度与马克斯坦长度判定的火焰发展趋势相同,即向外传播的火焰趋于稳定;爆炸物的爆炸特征值最大值出现在0.5 m处,壁面的爆炸特征值偏小。 相似文献
13.
Jiao Lei Naian Liu Linhe Zhang Haixiang Chen Lifu Shu Pu Chen Zhihua Deng Jiping Zhu Kohyu Satoh John L. de Ris 《Proceedings of the Combustion Institute》2011,33(2):2407-2415
The medium-scale fire whirl was extensively investigated by experimental means, in order to establish correlations of the burning rate, flame height and flame temperature of fire whirl, and to clarify the difference between fire whirls and general pool fires. Experimental observations and data confirmed that a free burning fire whirl is a highly stable burning phenomenon with large quasi-steady periods. Burning rates of fire whirls depend on pool diameter similarly to those of general pool fires; however the transition turbulent burning occurs sooner as the pool diameter increases. The lip height seems to have little effect on the burning rate of fire whirls. The correlation was proposed to couple the height of fire whirl to the fire release rate and ambient circulation. It correlates the data from both this work and the literature. Radial temperature profiles in the continuous region of the fire whirl were confirmed to be hump-type, implying the existence of fuel-rich inner core. The pool diameter and heat release rate do not significantly affect the radial temperature profiles in non-dimensional radial coordinates. It was found that the fire plume of fire whirl involves three distinct zones just like that of pool fire, but with different normalized ranges. Fire whirls maintain a higher ratio of continuous flame height to the overall flame height, and also higher maximum centerline excess temperature in continuous flame region, as compared to general pool fires. It was further demonstrated that the fire whirl plume at its origin behaves like a turbulent jet with moderate swirling, and then tends to become buoyancy dominated downstream, with slight swirling. With an increase in dimensionless height adjusted by the plume origin, the plume centerline excess temperature decays rapidly and approaches the theoretical value of −5/3 for free buoyancy plume. 相似文献
14.
We study vortex flame radiation in laboratory conditions. A fire torch was burning from a tank, which was fixed at the axis of uprising swirl airflow. Ethanol was used as a fuel. Processing of a sequence of thermograms of a swirling torch is described. The vortex flame revolutions were calculated using FFT of time pulsations of a signal from a thermal imaging system. 相似文献
15.
Modes of particle combustion in iron dust flames 总被引:1,自引:0,他引:1
François-David Tang Samuel Goroshin Andrew J. Higgins 《Proceedings of the Combustion Institute》2011,33(2):1975-1982
The so-called argon/helium test is proposed to identify the combustion mode of particles in iron dust flames. Iron powders of different particle sizes varying from 3 to 34 μm were dispersed in simulated air compositions where nitrogen was replaced by argon and helium. Due to the independence of the particle burning rate on the oxygen diffusivity in the kinetic mode, the ratio between the flame speeds in helium and argon mixtures is expected to be smaller if the particle burning rate is controlled by reaction kinetics rather than oxygen diffusion. Experiments were performed in a reduced-gravity environment on a parabolic flight aircraft to prevent particle settling and buoyancy-driven disruption of the flame. Uniform suspensions of the iron powders were produced inside glass tubes and a flame was initiated at the open end of the tube. Quenching plate assemblies of various channel widths were installed inside the tube and pass or quench events were used to measure the quenching distance. Flame propagation was recorded by a high-speed digital camera and spectral measurements were used to determine the temperature of the condensed emitters in the flame. The measured flame speeds and quenching distances were in good agreement with previously developed one-dimensional, dust flame model where the particles are assumed to burn in a diffusive mode and heat losses are described on a volumetric basis. However, a significant drop of the ratio of flame speeds in helium and argon mixtures was observed for finer 3 μm particles and was attributed to a transition from the combustion controlled by diffusion for larger particles to kinetically controlled burning of micron-size particles. In helium mixtures, the lower flame temperatures measured in suspensions of fine particles in comparison to larger particles reinforces this assumption. 相似文献