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分析了循环流化床锅炉结焦的影响因素,认为主要是床料对结焦的影响、燃料特性对结焦的影响、密相区的燃烧份额对结焦的影响,从而提出结焦事故预防措施,保证了循环流化床锅炉的正常稳定运行。 相似文献
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三废混燃流化床及余热回收锅炉技术是目前迅速发展起来的一项高效、清洁燃烧技术。而结焦是流化床锅炉运行中较为常见的故障,它直接影响到锅炉的安全经济运行。文章结合三废混燃流化床锅炉的运行特点,根据几年来的流化床锅炉调试和运行经验,分析流化床锅炉结焦的主要原因,并对如何预防流化床锅炉结焦进行了探讨。笔者从结焦形成机理的分析入手,阐述锅炉结焦后对机组热效率、出力的影响及安全性的危害,以及通过对煤质特性、炉膛温度水平、炉内空气动力场状况等影响锅炉结焦因素的分析,结合本厂实际情况提出了从控制燃煤质量、合成氨系统弛放气与造气吹风气投入量、加强运行操作、进行技术改造等几方面措施来减少或预防锅炉结焦。 相似文献
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在社会经济飞速发展的今天,循环流化床锅炉在很短时间内发展迅速,这是因为它具有一系列的优势,比如效率很高,污染较低等等。但是通过长期的实践研究发现,在新型循环流化床锅炉运行过程中,会出现结焦的事故,需要引起人们的重视。本文简要介绍了循环流化床锅炉高温结焦产生的原因,然后结合这些原因提出了相应的处理预防措施,希望可以提供一些有价值的参考意见。 相似文献
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<正> 一、关于结焦熄火问题沸腾燃烧锅炉在运行期,由于操作水平不高,没有掌握燃料特性和流化床燃烧的规律,一般都容易产生结焦和熄火。要防止结焦熄火,需先了解结焦和熄火形成的原因。流化床层中结焦有两种现象:一是“高温结焦”。就是床内料层中温度超过了煤的灰熔点 t_1,使整个炉排结了一层焦。焦渣的表面有一层玻璃化的熔渣,很坚硬,又不易捣碎。根据我省煤种情况,一般烧无烟煤、石煤和炉渣时,床层温度超过1100——1150℃,就会发生“高温结焦”。烧烟煤和煤矸石时,床层温度超过1000——1050℃就会产生“高温结焦”。个别情况床温超过1200 相似文献
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就75L/h循环流化床锅炉点火、运行及压火再启动过程中结焦原因进行了分析,提出了调整一次风量、控制入炉煤质等改进措施,措施实施后,避免流化床锅炉结焦。 相似文献
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In a batch experimental equipment, the behavior of a sawdust dryer in a vibrating fluidized bed is analyzed. Empirical data concerning fluidization velocities, pressure drops and drying kinetics was obtained, and advantages of using vibration in the drying chamber, relative to a conventional fluidized bed, are shown. This technique is presented as an alternative to solve problems of solid agglomeration and bed defluidization. Results show that it is possible to dry sawdust with more than 2 kg/kg moisture, in a vibrating bed keeping a high degree of bed homogeneity and high quality of fluidized state. 相似文献
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ABSTRACT In a batch experimental equipment, the behavior of a sawdust dryer in a vibrating fluidized bed is analyzed. Empirical data concerning fluidization velocities, pressure drops and drying kinetics was obtained, and advantages of using vibration in the drying chamber, relative to a conventional fluidized bed, are shown. This technique is presented as an alternative to solve problems of solid agglomeration and bed defluidization. Results show that it is possible to dry sawdust with more than 2 kg/kg moisture, in a vibrating bed keeping a high degree of bed homogeneity and high quality of fluidized state. 相似文献
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引言 在流化床乙烯气相聚合过程中,由于传热速率较低(与淤浆工艺相比),聚合物小颗粒容易聚集在一起形成结块,若不及时采取措施,将影响流化状态.而不良的流化状况经常导致装置不能满负荷、长周期地运转,严重时会"熔床",继而停产.为了保证流化床长期稳定的运行,聚合物颗粒结块的监测就变得十分重要.目前工业生产中主要根据流化松密度、反应温度、床高等参数的突变和γ射线法来检测结块.前者多依赖人为经验的判断,漏报、误报的情况时有发生.而γ射线法则对人体存在致命的伤害.因此,发展一种简单快捷、灵敏准确、安全环保的结块测量技术成为当务之急. 相似文献
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Agglomeration is a major problem in biomass fired fluidized bed combustors and gasifiers. Mechanism, reduction options and detection techniques of agglomeration are reviewed. Agglomeration may be classified broadly into three types: defluidization induced agglomeration, melt‐induced agglomeration and coating‐induced agglomeration. Sodium and potassium content of the biomass are the major contributors to the agglomeration in biomass fired fluidized beds. Higher temperature, lower fluidizing velocity and coarser bed particles also increase the risk of agglomeration. Alternative bed materials, additives or the co‐combustion of biomass with other fuels can reduce agglomeration potential of a fluidized bed. Two agglomeration detection techniques are discussed: controlled fluidized bed agglomeration and early agglomeration recognition system. 相似文献
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对并列流化床煤气化炉内的结志进行了包括光学显微镜,热重,X射线分析等多种方法的实验研究,分析了结块形成的过程机理,探讨了防止结块的相应措施。 相似文献
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流化床反应器的物料结块故障不仅影响产品质量,严重的还会影响生产。为了监测流化床反应器的物料结块故障,提出了一种基于压电声波传感器和声纹特征提取的故障监测方法。在流化床外壁粘贴压电陶瓷声波传感器,采用长屏蔽电缆电荷传输和音频采样方式,监测流化床内物料撞击床壁的声波信号。分析了正常颗粒物料和物料结块情况下声波信号的时域波形、功率谱和声纹特征,重点比较了正常信号和故障信号声纹特征的稳定性和可区分度。通过提取声纹特征,运用神经网络模型实现了对物料结块故障的准确监测。用不同位置声波传感器的感测信号验证故障监测模型的结果验证了这种方法具有较高的时空域鲁棒性。用不同信号抽取率对原始信号进行了重采样,对重采样数据分别进行了声纹特征提取、监测模型的训练和检验,结果表明适当降低信号采样率不影响流化床物料结块的监测结果。为流化床物料结块故障监测问题提供了一种新的系统结构和实现方法。 相似文献
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The development of a coal pyrolysis reactor and a novel gas chromatography method for fast on-line composition analysis of pyrolysis products are presented. The annular fluidized bed reactor system minimizes particle agglomeration during the pyrolysis of plastic coals and the new column switching technique significantly reduces the time required for measuring the composition of low-volatile pyrolysis gases on a conventional gas chromatograph. Data from representative pyrolysis runs are presented and discussed. 相似文献
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Korina Terrazas‐Velarde Mirko Peglow Evangelos Tsotsas 《American Institute of Chemical Engineers》2011,57(11):3012-3026
Particle formation during fluidized bed spray agglomeration is modeled by a Monte Carlo method. The methodology is based on the micromechanisms occurring within the bed. The most important model parameters are identified as interparticle collision time, deposited droplet drying time and droplet addition time. It is found that a high number of collisions leads to a negligible role of the drying mechanism. In the real bed, however, the process is dependent on the gas inlet temperature. This indicates that the number of collisions relevant to agglomeration is relatively low. The accordance of the model with experimental results for variations of several process parameters demonstrates that the approach is a promising way to simulate the formation of agglomerates. In addition, the model is able to reproduce slower agglomeration at increased temperatures. This result is, for the first time, based on physical mechanisms rather than on the use of fitted agglomeration kernels. © 2011 American Institute of Chemical Engineers AIChE J, 2011 相似文献