共查询到19条相似文献,搜索用时 187 毫秒
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流态色谱吸氧法测定煤自燃倾向不合理性分析 总被引:4,自引:2,他引:2
通过理论与实验结果的分析,指出流态色谱吸氧法测定煤炭自燃倾向性高低未能反映煤的氧化过程与氧化反应的实质,流态色谱吸氧法的指标体系不科学性;同时指出煤的自燃倾向性是反映煤在低温氧化条件下煤的吸氧与氧化放热的化学性质,煤的自燃倾向性主要由煤在某反应温度条件下具有反应活化能值的分子数及反应分子活化速率决定的;煤炭自燃倾向性高低的指标应采用氧化过程的放热量(或吸氧量)的积累指标或趋势指标. 相似文献
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为研究煤氧化自燃的反应机理,对4种不同煤样进行热重实验取得TG-DSC曲线,运用Starink法求解出煤样在达到着火点之前的表观活化能,对煤的氧化自燃过程进行研究。研究结果表明:煤的氧化自燃过程大致分为失水、氧化和燃烧3个阶段,煤的氧化阶段对煤的自燃起到关键性的作用,并且煤在氧化阶段的表观活化能随温度的升高而逐渐升高。煤样的吸氧量的大小与氧化阶段的最大表观活化能成反比,越容易发生自燃的煤样,吸氧量越大,氧化阶段的最大表观活化能越小。因此可以采用煤氧化阶段的最大表观活化能作为一项指标鉴定煤自燃倾向性。 相似文献
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煤层自燃倾向性色谱吸氧法测定实验研究 总被引:1,自引:0,他引:1
本文介绍了用流动色谱吸氧法测定煤对流态氧的吸附能力,并通过吸氧量表征煤的氧化自燃性能,此方法简单、快速、可行。最后采用流动色谱吸氧法对薛村矿煤样的自燃倾向性进行了测定,测试结果与生产过程中发生的自燃现象有很好的符合性。 相似文献
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基于氧气是自燃发生的必要条件、吸氧法测定煤的自燃倾向性是目前较成熟和理论认同的方法,从吸附时间及吸附温度对不同煤种进行了吸氧量的测定,并分析研究了吸氧法测定煤自燃倾向性中氧气的吸附特性。 相似文献
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低含水状态煤自燃倾向性实验研究 总被引:4,自引:2,他引:2
水分对煤自燃的影响十分复杂。应用TG-DSC技术,针对某一矿区对含水量较低状态下的煤样的氧化规律进行研究,测定其失重率、吸氧量、放热速率和放热量等参数,分析在较低含水状态下水对煤自燃倾向的影响。实验结果表明:含水量较低的情况对煤体的自燃有着促进作用,煤的自燃倾向性增加。当煤样的含水量超过一个临界值时,其吸氧量和放热量都会降低,煤的自燃倾向性降低。为防止煤的自燃倾向性的增加,煤体的含水量要保持在较高的程度。 相似文献
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何启林 《煤炭学报(英文版)》2008,14(4):554-557
Based on experiment results and theoretical analysis, pointed out that the method of coal susceptibility to spontaneous combustion
determination with fluid oxygen adsorption can not present the essence of coal oxidation process and oxidation reaction. The
method is incorrect, paying attention at one aspect and ignoring the rest. The method is not reasonable for coal susceptibility
to spontaneous combustion determination. Susceptibility to spontaneous combustion of coal reflects chemical property of coal
oxidation with oxygen absorption and heat release at low temperature. Coal’s susceptibility to spontaneous combustion is mainly
decided by the number of molecules with reaction activation energy and activation molecule production rate at certain temperature.
Therefore, index of susceptibility to spontaneous combustion should adopt accumulative value or trend of heat release or oxygen
adsorption during oxidation process.
Supported by Innovative Team in Science and Technology of Anhui Province College and Universities(2006KJ005TD); Science of
Fire, Nature Science Foundation of China(2001CB409600) 相似文献
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The characteristic of coal spontaneous, combustion includes oxidative property and exothermic capacity. It can really simulate the process of coal spontaneous combustion to use the large-scale experimental unit loading coal ! 000 kg. According to the field change of gas concentration and coal temperature determined through experiment of coal self-ignite at low temperature stage, and on the basis of hydromechanics and heat-transfer theory, some parameters can be calculated at different low temperature stage, such as, oxygen consumption rate, heat liberation intensity. It offers a theoretic criterion for quantitatively analyzing characteristic of coal self-ignite and forecasting coal spontaneous combustion. According to coal exothermic capability and its thermal storage surroundings, thermal equilibrium is applied to deduce the computational method of limit parameter of coal self-ignite. It offers a quantitative theoretic criterion for coal self-ignite forecasting and preventing. According to the measurement and test of spontaneous combustion of Haibei coal, some token parameter of Haibei coal,spontaneous combustion is quantitatively analyzed, such as, spontaneous combustion period of coal, critical temperature, oxygen consumption rate, heat liberation intensity, and limit parameter of coal self-ignite. 相似文献
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流化床煤燃烧过程中砷析出特性研究 总被引:3,自引:0,他引:3
通过流化床燃烧实验,研究了煤燃烧过程中砷的析出特性,并根据煤的浮-沉试验探讨了煤中砷的赋存形态.结果表明:砷析出率随燃烧温度的升高而增加,在600~700 ℃时,燃烧温度对砷析出率的影响较小, 700~900 ℃是砷析出的主要温度范围且燃烧温度对砷析出率的影响显著;砷析出率随燃烧时间的增加而增大,但前10 min是砷析出的主要阶段;砷在煤中主要以有机态和无机态两种形式存在,无机砷主要赋存在黏土矿物和硫铁矿中,砷析出率随煤中有机砷比例的增加而增大. 相似文献
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