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151.
Chemical looping gasification (CLG) of Ningdong coal by using Fe2O3 as the oxygen carriers (OCs) was studied, and the gasification characteristics were obtained. A computation fluid dynamics (CFD) model based on Eulerian‐-Lagrangian multiphase framework was established, and a numerical simulation the coal chemical looping gasification processes in fuel reactor (FR) was investigated. In addition, the heterogeneous reactions, homogeneous reactions and Fe2O3 oxygen carriers' reduction reactions were considered in the gasification process. The characteristics of gas flow and gasification in the FR were analyzed and it was found that the experiment results were consistent with the simulation values. The results show that when the O/C mole rate was 0.5:1, the gasification temperature was 900 ℃ and the water vapor volume flow rate was 2.2 ml·min-1, the mole fraction of syngas reached a maximum value of the experimental result and simulation value were 71.5% and 70.2%, respectively. When the O/C mole rate was 0.5:1, the gasification temperature was 900 ℃, and the water vapor volume flow was 1.8 ml·min-1; the gasification efficiency reached the maximum value was 62.2%, and the maximum carbon conversion rate was 84.0%. 相似文献
152.
The hydrodynamics and mass transfer characteristics of a lab-scale jet bubbling reactor(JBR) including the gas holdup, volumetric mass transfer coefficient and specific interfacial area were assessed experimentally investigating the influence of temperature, p H and superficial gas velocity. The reactor diameter and height were 11 and 30 cm,respectively. It was equipped with a single sparger, operating at atmospheric pressure, 20 and 40℃, and two p H values of 3 and 6. The height of the liquid was 23 cm, while the superficial gas velocity changed within 0.010–0.040 m·s~(-1) range. Experiments were conducted with pure oxygen as the gas phase and saturated lime solution as the liquid phase. The liquid-side volumetric mass transfer coefficient was determined under unsteady-state oxygen absorption in a saturated lime solution. The gas holdup was calculated based on the liquid height change, while the specific interfacial area was obtained by a physical method based on the bubble size distribution(BSD) in different superficial gas velocities. The results indicated that at the same temperature but different p H, the gas holdup variation was negligible, while the liquid-side volumetric mass transfer coefficient at the p H value of 6 was higher than that at the p H = 3. At a constant p H but different temperatures, the gas holdup and the liquid-side volumetric mass transfer coefficients at 40℃ were higher than that of the same at 20℃. A reasonable and appropriate estimation of the liquid-side volumetric mass transfer coefficient(kla) in a pilot-scale JBR was provided which can be applied to the design and scale-up of JBRs. 相似文献
153.
Visual process monitoring is important in complex chemical processes. To address the high state separation of industrial data, we propose a new criterion for feature extraction called balanced multiple weighted linear discriminant analysis(BMWLDA). Then, we combine BMWLDA with self-organizing map(SOM) for visual monitoring of industrial operation processes. BMWLDA can extract the discriminative feature vectors from the original industrial data and maximally separate industrial operation states in the space spanned by these discriminative feature vectors. When the discriminative feature vectors are used as the input to SOM, the training result of SOM can differentiate industrial operation states clearly.This function improves the performance of visual monitoring. Continuous stirred tank reactor is used to verify that the class separation performance of BMWLDA is more effective than that of traditional linear discriminant analysis, approximate pairwise accuracy criterion, max–min distance analysis, maximum margin criterion, and local Fisher discriminant analysis. In addition, the method that combines BMWLDA with SOM can effectively perform visual process monitoring in real time. 相似文献
154.
锆合金疖状腐蚀研究综述 总被引:6,自引:0,他引:6
疖状腐蚀是沸水堆中锆合金表面经常发生的1种局部腐蚀现象,它的产生直接影响包壳管的使用寿命和反应堆的安全性,为了全面认识疖状腐蚀的发生、发展及其控制因素,本文总结了国内外疖状腐蚀研究方面的一些主要成果,介绍了疖状蚀斑的形貌、形成机理以及及影响因素。在形成机制方面,目前主要有KUWAE的氢积聚模型和周邦新的形核长大模型。在疗状腐蚀的影响因素方面,认为主要有表面影响、热处理影响、合金成分影响、第二组影响、辐照影响等。最后指出了提高材料抗疗状腐蚀性能的工艺措施:提高Fe Cr含量、降低Sn含量、昼减少淬火后的退火次数和退火温度、降低锆合金制品的表面粗糙可以有效提高锆合金的抗疖状腐蚀能力,最根本的措施还是使用含铌新锆合金。 相似文献
155.
156.
下喷式环流反应器是一种用于强化气-液两相反应过程的新型装置,虽然已在工业上有了较广泛的应用,但对其理论研究远未成熟,其工业装置的设计仍依赖于实验和经验。本文借助实验室自制实验装置,对下喷式环流反应器环隙气含率的影响规律进行了研究。首先,对喷射器的吸气量进行了测量,获得了不同条件下喷射器最大吸气量的性能曲线;在此基础上,分别研究了气相流量、液相流量以及喷射器安装位置对环隙气含率的影响规律。结果表明:气相流量和液相流量对气含率具有重要的影响,随着气相流量和液相流量的增大,气含率快速提高,而喷嘴位置对气含率的影响相对较小;考虑到增加气相流量和液相流量所需要的能耗和设备代价,通过增加液相流量来达到提高气含率的目的是优选方案。 相似文献
157.
M. Rahman 《化学,工程师,技术》1975,47(17):729-729
158.
气液固三相床中合成甲醇与二甲醚 总被引:3,自引:0,他引:3
叙述了气液固三相催化反应技术的主要特点和应用领域,并着重介绍了三相床合成甲醇和二甲醚的试验研究内容和成果。 相似文献
159.
160.