共查询到19条相似文献,搜索用时 250 毫秒
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循环流化床复合压降数学模型 总被引:2,自引:3,他引:2
建立了同时考虑循环流化床宽筛分物料动态质量平衡以及送风系统流体网络特性的复合压降模型,这是对以往数学模型中采用静态质量平衡及割裂风量和压降关系的修正和改进。该模型可以正确地反映如排渣量、给风流量等锅炉运行参数变化时,床内压降,床料筛分,密相床高度等参数的动态变化情况,从而为建立循环流化床整体动态数学模型奠定了基础。 相似文献
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利用循环流化床内气-固两相流动等基础方面的研究成果,根据本文床内气固浓-淡流动模型,建立适用不同结构参数的循环流化床燃烧模型,考虑了床内气体、固体颗粒的返混、循环过程,以及煤燃烧、NO的生成和分解、颗粒磨损等因素。在循环流化床燃烧试验台上进行实验研究,模型仿真结果和实验数据吻合良好,表明气固两相浓-淡流动模型所建立的循环流化床燃烧系统模型可以正确地模拟循环流化床的燃烧过程。 相似文献
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循环流化床物料平衡是循环流化床燃烧的核心和基础,它影响到循环流化床燃烧效率和脱硫效率,并决定燃烧室内的热负荷分布。循环流化床“一进二出”的物料平衡系统是循环流化床的核心概念,也是理解循环流化床物料平衡的关键。本文介绍并分析了循环床物料平衡的某些问题,如循环流化床定态设计、床料质量和物料平衡模型等。循环流化床运行需要高的“床料质量”和较大物料循环量,要求流化床锅炉分离器分离效率曲线存在一个清晰的100%分离粒径截止点。循环流化床内物料平衡除了受分离器效率影响外,还受到给煤成灰及磨耗特性、床内颗粒分层、排渣方式及效率等因素的影响。 相似文献
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循环流化床锅炉燃烧优化控制方法,对整台机组进行协调控制的基础上,当机组投入协调控制方式后,以汽机调负荷,锅炉调压力,协调控制系统接受负荷指令;当汽机负荷变化较大时,对流化床锅炉耦合性强的负荷、主汽压、床温、床压等参数进行了解耦,整个系统保持在总的能量平衡的方式下调整,通过改变人炉的给煤量来改变炉膛内的残碳量,残碳量表征床料中未燃尽的燃料,这些燃料将用来快速响应电网负荷指令所需的能量; 相似文献
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A mathematical model has been developed to describe the agglomeration process in bio-fuel fired fluidized bed combustor. Based on the balance mechanism of the adhesive force caused by liquid bonding between two parti- cles and the breaking force induced by bubbles in the fiuidized bed, the model considers modified Urbain model and chemical equilibrium calculations using FactSage modeling. This model prediction accounts for the evolve- ment of the adhesive and breaking forces, and clearly demonstrates that the different composition of ash, the in- creasing liquid phase matter and the fiuidization velocity cause defluidization in fluidized bed. In this model, it is the first time to hypothesize that the bonding stress between two particles is proportional to mass fraction of liq- uid phase and inversely proportional to the diameter of particles and viscosity of liquid phase. The defluidization time calculated by this model shows good agreement with that from the experimental data. 相似文献
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2MW加压喷动流化床煤部分气化特性的研究 总被引:1,自引:0,他引:1
在热输入2MW的中试规模加压喷动流化床部分气化试验装置上,采用徐州煤烟进行了连续12h的加压部分气化试验研究,研究了在深床条件下煤部分气化特性,以及汽煤比的变化对部分气化的影响。研究结果表明:在合适的喷动风和流化风配比下,可实现深床气化,使气化反应基本达到化学平衡;在其它条件不变的前提下,汽煤比增加,气化炉温度下降,煤气中H2含量有较大幅度的提高,煤气热值也有所增加。文章的最后将试验的主要指标与国内外类似规模装置上获得的数据进行了比较。图6表5参10 相似文献
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A mathematical model has been developed for the oxygen mass balance for a 10 MW fluidized bed coal combustion power plant operated at Jamadoba (TISCO, India). Assuming the three phase theory of fluidization, the fluid bed is considered to consist of a number of equivalent stages in series. Within each stage, an exchange of gas takes place between the bubble, cloud-wake, and emulsion phases. An effective chemical reaction rate of char combustion has been derived considering the single film theory of char combustion for shrinking particles. The model has been used to predict the consumption of oxygen in the fluidized bed combustor, the outlet gas composition, variation of oxygen concentrations in different phases and also the variation of average oxygen concentration along the bed height. Model predictions were compared with plant data, and reasonable accuracy was obtained. 相似文献
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实验用钢瓶气体模拟实际烟气,研究了在微型鼓泡床中反应的pH值、温度及浆液中微量的氟离子和氯离子对石灰石溶解速度的影响。根据质量作用定律和阿仑尼乌斯方程提出了石灰石溶解速度的数学公式,式中各项参数物理意义明确,可统一描述各工况下石灰石溶解速度。同时测出了该实验使用的石灰石溶解速度的各参数,并得出了浆液中微量的氟离子和氯离子均不利于石灰石的溶解。利用本文提出的模型可以比较不同石灰石的活性,从而针对不同品种的石灰石设计合适的浆池大小,这对于研究湿法烟气脱硫具有重要意义。 相似文献
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Turan Çalban 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2013,35(5):479-485
In this study, drying of a lignite from Erzurum Ispir-Karahan province, with air in a batch fludized bed, was investigated. In the experiments, effects of bed height and initial moisture concentration of the coal on the drying behavior were studied. It was found that the drying rate increased with a decrease in bed height. Also, coal particles with an initial lower moisture content showed a marginal decrease of drying rate compared with higher moisture content particles. It was also observed that the equilibrium moisture content, and the time taken to reach the equilibrium moisture content, decreased with decreasing initial moisture concentration, while the critical moisture content generally decreased. Also, it fixed with decreasing bed height, while the critical moisture content increased. 相似文献
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乙烯水解生产乙二醇过程中,会产生大量乙二醇污水,该污水有机物浓度高,COD值高达1500~4000mg/L,污水中含有乙二醇、二乙二醇、醚类、醛类有机物质,对微生物具有一定的毒性。上海石化利用生物流化床技术,开展乙二醇污水预处理工业试验研究。试验结果表明,在污水pH值为5.5~11.0,温度为25~30℃,反应停留时间为10~15h,进水COD值为1000~3000mg/L条件下,处理后COD值小于500mg/L,达到企业预处理标准,COD去除率达到90%,流化床污水处理系统抗COD、pH冲击能力强,运行较为平稳。与传统氧化沟处理工艺对比,流化床工艺的反应效率、出水水质均优于氧化沟工艺,停留时间仅为氧化沟法的1/4。研制出大型生物流化床处理乙二醇污水工业试验装置,该装置主要包括均质水解罐、生物流化床、加药罐和空气压缩机。该装置最大容积负荷达到6.0kg COD/(m3.d),平均容积负荷达到3.1kg COD/(m3.d),是传统氧化沟法平均容积负荷的4倍。生物流化床工艺实现了污水处理的装置化、集成化,且占地面积小,操作费用低,处理效果好,抗冲击能力强。 相似文献