共查询到18条相似文献,搜索用时 171 毫秒
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混合工业污泥燃烧及动力学特性实验研究 总被引:5,自引:1,他引:5
为了更好地利用工业污泥,有必要对它的燃烧特性进行研究,文中利用热重法研究了3种典型工业污泥的单组分试样以及按不同质量比例混合后多组分试样的着火、燃尽、综合燃烧特性、反应放热性能和动力学特性,并计算出燃烧过程的动力学参数。结果表明:由于工业污泥的高挥发分、低固定碳,其着火和燃尽特性比较好,而综合燃烧特性不是很高;工业污泥着火温度与挥发分含量以及成分有关,而含碳量越高,越不易燃尽,燃尽性能越差,但燃烧越剧烈,其综合燃烧性能越好;燃烧放热主要分为挥发分燃烧和固定碳燃烧两个阶段,前者燃烧剧烈,有明显的放热峰且活化能较低,后者放热峰变小,活化能变高;混合工业污泥中的单一组分在燃烧过程中基本保持各自的着火和燃尽特性,在热重分析中的燃烧特性可以用各个单一组分试样的燃烧特性进行叠加来表示。 相似文献
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《电站系统工程》2016,(1):5-8
采用德国NETZSCH STA409PC同步热分析仪对广东地区生物质成型燃料分别在20 K/min、30 K/min和40 K/min的升温速率下进行了热重动力学实验,实验从室温升至终止温度1273 K,并由热重实验数据计算可燃特性指数、燃烧特性指数等特征参数和动力学参数,分析升温速率对其燃烧特性的影响。计算结果表明,随着升温速率的提高,最大失重速率点向高温一侧偏移,最大失重速率升高,可燃特性指数、燃烧特性指数和燃尽特性指数都随之升高。热解燃烧阶段反应级数较大,为1.32~1.45,焦炭燃烧阶段较小,为0.91~1.15,且该阶段反应级数随升温速率的提高有一个减小的趋势。热解燃烧阶段活化能低于焦炭燃烧阶段,且随升温速率变化不明显,分别为88.32~103.80 k J/mol和101.31~123.72 k J/mol。对比其他生物质燃料,其反应级数较高。 相似文献
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采用热重分析法(TGA)对胶粉、煤粉及胶粉与煤混合物燃烧特性进行分析, 研究煤粉与胶粉混合比例对混合燃料着火特性和燃尽特性的影响规律。结果表明: 胶粉的燃烧特性与煤的燃烧有较大的区别, 高灰分煤的燃烧主要受固定碳燃烧控制; 而胶粉在燃烧过程中, 其高挥发分的析出和燃烧起主要作用。与煤粉相比, 掺10%、30%和50%的胶粉后燃料的着火温度分别降低8、30℃和80℃, 且促进了燃料的燃烧速率, 这主要是由于胶粉含大量挥发分且在较低温度下即可明显析出和燃烧的结果, 胶粉与煤的混烧有利于改善高灰分煤的着火和燃尽特性。 相似文献
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为了探究烘焙对生物质燃烧特性以及燃烧机制的影响,研究了不同烘焙条件下典型秸秆的燃烧失重特性和放热行为。选择棉杆和稻杆为主要研究对象,采用热重分析仪与差热扫描量热仪连用分析了秸秆的燃烧特性。实验结果表明:秸秆燃烧过程主要包括脱水、挥发分和固定碳燃烧,经烘焙处理后,秸秆的着火温度明显降低,燃烧更为充分,并且燃烧放热量随着烘焙温度的提高而进一步加大。采用非等温积分法分析了烘焙秸秆的热动力学特性和燃烧机制,发现稻杆的挥发分燃烧过程为1级反应,稻秆主要为挥发分的燃烧,棉杆的活化能较高,并且主要是固定碳的燃烧。农业秸秆烘培预处理对其燃烧特性的改善有明显的作用。 相似文献
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金属化合物对工业污水污泥燃烧的
催化作用及机制 总被引:9,自引:1,他引:8
用热重法研究了不同金属化合物对含工业污水污泥的助燃作用,计算了添加不同金属化合物前后污泥燃烧的特征指数和燃烧反应动力学参数,并以酸洗污泥作为对比,对不同金属化合物的助燃效果和催化机制进行了分析。结果表明,含工业污水污泥中挥发分的析出和燃烧制约着整个燃烧过程,并且污泥在低温段和高温段的燃烧特性不同。污泥添加不同金属化合物K2CO3、NaCl和Al2O3后,其着火点有一定的下降,对污泥的燃烧有促进作用;不同金属元素化合物的加入对污泥燃烧性能有一定的改善,并且在燃烧的不同阶段金属化合物表现出不同的催化能力,其中K2CO3的催化性能强于NaCl和Al2O3。污泥经过酸洗后,燃烧反应速率有明显的提高,活化能降低,综合燃烧性指数提高。不同金属化合物对污泥燃烧的催化机制不同,对污泥着火性能的催化主要表现在金属促进了污泥中挥发性有机物的释放。金属对污泥燃烧催化的机理是金属充当氧的载体,加快氧气扩散速度,促进了氧的转移。 相似文献
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煤和石油焦混合燃料在循环流化床中的燃烧特性 总被引:3,自引:0,他引:3
通过热天平对烟煤、石油焦和3种不同配比的煤和石油焦混合燃料的着火和燃烧特性进行了实验研究,然后在0.6 MW中试规模循环流化床试验台上进行了石油焦及其与煤的混合燃料的着火和燃尽特性研究。结果表明,石油焦并不是一种非常难燃的燃料,它的燃烧特性介于烟煤和无烟煤之间,其着火点温度和燃尽温度也介于烟煤和无烟煤之间,但更接近烟煤。 相似文献
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大同烟煤增压富氧燃烧的热重实验研究 总被引:1,自引:0,他引:1
利用TherMax500型加压热天平研究了大同烟煤在增压富氧条件下的燃烧行为,主要考察压力对其燃烧特性的影响。实验结果表明,煤粉常压时的非均相着火,在中低压力下转变成均相着火,当压力增加到4 MPa后又逐渐向非均相着火过渡,并在6 MPa时完全转变成非均相着火。在均相燃烧时,随着压力的升高,挥发分燃烧速率逐渐加快,煤粉热解程度逐步加深。由于不同压力下着火方式的改变,煤粉的着火温度及燃尽温度并非随着压力的增加而单调变化,因而导致煤粉的综合燃烧特性指数S随着压力的增加先升高后降低。 相似文献
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When designing and selecting burning equipment for low volatile coal fired boilers,the primary concerns are about coal ignition and burnout.The characteristics of ignition and burnout are analyzed for ... 相似文献
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The study results of ignition of organic coal-water fuel (OCWF) compositions were considered. The main problems associated with investigation of these processes were identified. Historical perspectives of the development of coal-water composite fuel technologies in Russia and worldwide are presented. The advantages of the OCWF use as a power-plant fuel in comparison with the common coal-water fuels (CWF) were emphasized. The factors (component ratio, grinding degree of solid (coal) component, limiting temperature of oxidizer, properties of liquid and solid components, procedure and time of suspension preparation, etc.) affecting inertia and stability of the ignition processes of suspensions based on the products of coaland oil processing (coals of various types and metamorphism degree, filter cakes, waste motor, transformer, and turbine oils, water-oil emulsions, fuel-oil, etc.) were analyzed. The promising directions for the development of modern notions on the OCWF ignition processes were determined. The main reasons limiting active application of the OCWF in power generation were identified. Characteristics of ignition and combustion of coal-water and organic coal-water slurry fuels were compared. The effect of water in the composite coal fuels on the energy characteristics of their ignition and combustion, as well as ecological features of these processes, were elucidated. The current problems associated with pulverization of composite coal fuels in power plants, as well as the effect of characteristics of the pulverization process on the combustion parameters of fuel, were considered. The problems hindering the development of models of ignition and combustion of OCWF were analyzed. It was established that the main one was the lack of reliable experimental data on the processes of heating, evaporation, ignition, and combustion of OCWF droplets. It was concluded that the use of high-speed video recording systems and low-inertia sensors of temperature and gas concentration could help in providing the lacking experimental information. 相似文献
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利用自制等温实验台炉模拟炉膛高温环境,研究了高温度1150~1550℃下煤粉燃烧特性,并同步测量了NO的生成量。结果表明:高温环境下煤粉燃烧可分为两个阶段,即挥发分和焦炭燃烧阶段。高温段显示提高温度可以较好地改善燃烧特性,同时温度由1150℃增加到1250℃时,燃烧失重速率增加幅度较其他温度区间大。NO瞬时排放浓度随燃烧经历了一个先增大后减小的过程,且峰值在燃烧过程前期。煤化程度越高,煤粉不能快速完成燃烧,焦炭中含N量大,释放缓慢,不能形成有效还原性气氛,使得总体NO排放较多。高温1550℃由空气产生的热力型NO高达3.5×10^-3mg/s。 相似文献
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LIU Jingyong ZHUO Zhongxu SUN Shuiyu ZHAO Suying YANG Zuoyi WANG Yujie XIE Wuming HUANG Rong 《热力发电》2014,(4)
Through thermogravimetric analysis,the effect of acid wash on burning performance of industrial sludge was studied.Both characteristic indexes and kinetic parameters of the sludge combustion were calculated before and after the acid treatment.Moreover,the combustion-supporting effect of acid wash was investigated.The results indicate that,there were four weight loss peaks during the sludge combustion,among which the two representing the volatile matter release and combustion weight loss were quite obvious,which played a dominant role in the entire combustion process.After acid pickling,the sludge's specific surface area increased,and its spatial structure and chemical composition also changed,which promoted release of the volatile organic matters in the sludge.Thus,the ignition occurred earlier and diffusion rate of the oxygen speeded up,making the combustion easier to go on.For the acid washed sludge,the activation energy reduced and the reaction reactivity increased,indicating the effect of spatial structure on assistant combustion were better than that of the self-contained metal on catalytic effect to combustion. 相似文献