Combustion characteristics and kinetic analysis of blended coal ofupgraded low rank coal and bituminous coal injected into blast furnace

Thermo-gravimetric analysis is performed to study the combustion performance of upgraded low rank coal,bituminous coal injected into blast furnace and their mixture.It’s studied the relationship between adding quantity of upgraded low rank coal and change rules of blended coal combustion index and their influence on each other.Blended combustion kinetics is analyzed by using the distributed activation energy model (DAEM).The results indicate that the combustion rate of upgraded low rank coal is faster than that of bituminous coal.With the increase of adding quantity of upgraded low rank coal in the blended coal,the ignition temperature gradually decreases,the combustible index and comprehensive combustion index increase,and burning effect gets better.The value of interaction factors K of all blended coals are greater than 1,which suggests that the mutual promotion between upgraded low rank coal and bituminous coal in the combustion process exists.The apparent activation energy of blended coals decrease with the increase of adding quantity of upgraded low rank coal,which indicates the combustion activity of blend coal gradually stronger.     

生物质醇解重质油燃烧动力学研究

在热重分析仪上研究马尾松、桉木和麦秸秆的醇解重质油的燃烧过程及其动力学特性。结果发现,这3种重质油燃烧过程均可分为3个阶段:1)室温到300℃,为小分子有机物挥发阶段;2)300～480℃,为挥发分析出与燃烧阶段;3)480℃以上,为固定碳燃烧与燃尽阶段。动力学计算结果表明,这3个阶段都符合一级反应过程。同时,麦秸秆醇解重质油快速燃烧阶段(300～480℃)活化能最低,对应的失重速率最大,为0.188%/min,且着火温度最低,为405℃,因而其最易于燃烧。     

Carbon‐mineralization kinetics in an organically managed Cambic Arenosol amended with organic fertilizers

The dynamics of C mineralization in an organically managed Cambic Arenosol amended with hen manure, a stabilized compost (compost), and three different combinations of both fertilizers (varying from a 1:100 to a 1:10 ratio) were studied during an incubation experiment to estimate the potential of such combinations to preserve/restore soil C content relative to single applications. A strong increase of the CO₂‐C emissions relative to the unamended soil (control) was observed after soil application of all five organic‐fertilizer treatments. A significantly higher amount of applied C was lost in hen‐manure treatment (648 mg CO₂‐C [g C applied]^–1) when compared to compost (159 mg CO₂‐C [g C applied]^–1) or to the three combined treatments (176–195 mg CO₂‐C [g C applied]^–1). The first‐order exponential model and the double exponential model were used to fit the C‐mineralization data in the treatments considered. Results showed that mixing “small” amounts of hen manure with compost did not affect the total amount of potentially mineralizable C, but significantly increased the mineralization rate constant. Clearly, combinations of both fertilizers promoted an initial faster mineralization of the organic matter, and consequently a faster release of nutrients, without affecting the total amount of C sequestered in soil.     

一种求算土壤流动法中动力学参数的数值微分法

本研究在辨析了土壤流动法中动力学参数的传统求算法的一些缺点之后,重新考察了流动法的特征,在此基础上提出了一种先通过数值微分－－五点三次多项式－－求算出反应速率之后,再依据反应速率求算动力学参数的方法,并动用该法求算了潮土对钾离子的吸咐、解吸咐动力学参数。结果说明该法具有很好的可靠性。     

球与定轴转动杆在完全弹性碰撞过程中的能量转换(b)

通过求解球与定轴转动杆完全弹性碰撞过程的非线笥动力学微分方程组,研究了碰撞过程中动能与压缩变形能之间的相互转换。得出了碰撞始末球的平动动能与杆绕定轴的转动动能之和明显不守恒的结论。     

偏心顶杆排种器的工作过程分析

为探明影响偏心顶杆排种器排种质量及工作性能的因素,建立了排种器的简化工作模型,推导出排种器工作时种子的位移和速度方程,界定了充种和投种过程．分析充种过程得知：型孔理论上应为椭圆型孔,并推导出椭圆型孔的大小与种子的大小、承种筒的外径和转速等之间的计算关系式．对投种过程分析得知：选择恰当的机组前进速度可保证排种器正常落种,提高种子的完好率．     

酵母DV10发酵低醇度椰子水的动力学研究

用酵母DV10发酵成熟椰子水并研究发酵过程中菌体浓度、底物浓度和产物浓度等变量随发酵时间的变化规律。应用Logistic方程和Leudeking-Piret方程建立了低醇度椰子水发酵过程中菌体生长、底物消耗和产物生成动力学模型,并对动力学拟合方程一阶求导,求出其发酵过程中菌种增长速率、酒精生成速率和底物消耗速率。方差分析结果表明:3个模型的拟合度分别为0.994、0.997、0.997,理论值和实验值的误差平均值分别为4.75%、4.36%和4.42%。因此,3个模型均可很好地阐明酵母DV10发酵低醇度椰子水过程的动态变化。     

椰壳活性炭孔结构对肌酐吸附性能影响及吸附动力学研究

考察了具有不同孔结构的椰壳活性炭对肌酐(CR)的吸附性能,研究了比表面积、孔径分布与肌酐吸附性能的关系,采用准一级、准二级和颗粒内扩散动力学模型对吸附数据拟合处理,确定了模型参数。试验结果表明:1~2.5 nm的微孔对肌酐吸附有利,平均孔径在2.2 nm附近的椰壳活性炭肌酐吸附量为104 mg/g;活性炭对肌酐的吸附能力取决于比表面积,总孔容,微孔率的共同作用。颗粒内扩散吸附并不是唯一的速率控制过程,椰壳活性炭对肌酐的吸附过程更符合准二级动力学模型t/qt=1/k2q2e+t/qe,相关系数均在0.99以上,表明吸附过程存在化学吸附。     

改性沸石对猪场沼液氮磷吸附特性与机理分析

针对猪场沼液氮磷含量高、有机污染严重、难以处理的问题,采用经氯化钠溶液改性沸石为载体对沼液中氮磷吸附特性和去除机理进行分析研究,考察了沸石投加量、吸附时间、沼液初始浓度等影响因素。结果表明:当沸石投加量为每100mL10g、吸附时间48 h时,最大氨氮去除率可达90.66%,氨氮饱和吸附量可达1.43 mg·g-1,最大总磷去除率可达85.97%,磷饱和吸附量可达0.16 mg·g-1。吸附后的沸石污泥含有大量氮磷元素,是一种优质缓释肥料。Freundlich、Langmuir方程均能较好地解析改性沸石的等温吸附过程,其吸附动力学符合准二级动力学模型,R2均达0.98以上。沸石对猪场沼液中有机态氮磷去除主要基于物理性吸附和沸石中的活性基团与有机官能团所产生的配位络合,无机态氮磷则主要以离子交换及吸附沉淀方式得以去除。