共查询到20条相似文献,搜索用时 93 毫秒
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催化蒸馏过程研究进展 总被引:26,自引:3,他引:26
对近年来丙化蒸馏过程研究进展了综述。介绍了催化剂装镇方式,对催化蒸馏所适应的反应类型、催化剂、工艺条件等进行了总结。介绍了塔内传质及流体力学特性、反应混合物的热力学行为、反应动力学、数学模型、塔设计过程集成的研究现状。提出了研究中的不足及今后的研究方向 相似文献
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GMT片材制备过程中预热过程的研究 总被引:1,自引:0,他引:1
本文通过有限差分法推导了用于描述树脂-玻纤毡-树脂三层排布结构下的非稳态及包含相变(但不考虑流动)的热传导过程,即对预热过程的热传导现象进行了数值模拟,并将模拟结果与实验测试值进行了比较,并探讨了预热过程的各种参数对GMT(玻璃纤维毡增强热塑性片材)片材制备过程中的预热过程的影响,同时给出了以减少预热时间的优化工艺条件,即提出了最有效地减少预热时间的手段是将中心层树脂(l3)从挤出机中挤出。 相似文献
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发酵过程自动化 总被引:4,自引:0,他引:4
王树青 《化工自动化及仪表》1993,20(5):1-6
分析了发酵过程中物理、化学、生物诸参数测量的进展;综述了发酵过程控制,诸如消泡、温度和压力、pH值、溶解氧浓度、补料控制等;介绍了状态估计、数字控制、优化控制在发酵过程中的应用。 相似文献
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阐述了采用"悬浮干燥过程优化控制技术"改造SPVC干燥装置的情况。运行数据表明,该技术提高了旋风干燥塔塔温控制精度、悬浮树脂成品的优级品率及挥发物指标。 相似文献
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本文评述了影响RO系统运行特性的因素。这些因素包括给水化学、模污染机理、设备的膜组件中污染物组成、防污剂及其应用实例。就此讨论了目前为防止污染开发防污剂为保养设备开发膜清洗剂的具体途径。 相似文献
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《化工自动化及仪表》1985,(5)
利用传热和传质的基本方程导出了回旋式烘窑的动态模型。该模型是以具有确定边界条件的四联立非线性双曲线型偏微分方程组来描述的,显示了烘干过程为一非线性很强的分布参数系统。用导出的复杂数学模型作为对象置于控制回路,简化模型用于参数估计,与辨识器结合以跟踪过程动态特性的变化,为控制系统的参数整定提供决策。在采用普通最小二乘参数估计法(LS)的基础上引入了仪表变量最小二乘参数估计法(IVLS),取得良好效果。 相似文献
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This paper combines grey model with time series model and then dynamic model for rapid and in-depth fault prediction in chemical processes. Two combination methods are proposed. In one method, historical data is in-troduced into the grey time series model to predict future trend of measurement values in chemical process. These predicted measurements are then used in the dynamic model to retrieve the change of fault parameters by model based diagnosis algorithm. In another method, historical data is introduced directly into the dynamic model to re-trieve historical fault parameters by model based diagnosis algorithm. These parameters are then predicted by the grey time series model. The two methods are applied to a gravity tank example. The case study demonstrates that the first method is more accurate for fault prediction. 相似文献
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A full two-fluid model of reacting gas-particle flows with an algebraic unified second-order moment turbulence-chemistry model for the turbulent reaction rate of NO formation are used to simulate swirling coal combustion. The sub-models are the k-ε-kp two-phase turbulence model, the EBU-Arrhenius volatile and CO combustion model, the six-flux radiation model, coal devolatilization model and char combustion model. The prediction results are in good agreement with the experimental results taken from references. 相似文献
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电解质NRTL模型的发展及应用 总被引:1,自引:0,他引:1
综述了电解质NRTL模型从最初的用于处理单一电解质、单一溶剂体系的两贡献模型发展成为能处理多电解质组分、混合溶剂体系的热力学模型,介绍了模型在电解质溶液相平衡计算中的应用。最后指出了此模型的优缺点和模型参数的发展方向。 相似文献
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电解质NRTL模型的研究进展及应用 总被引:1,自引:0,他引:1
电解质NRTL模型是重要的热力学局部组成模型。本文阐述了电解质NRTL模型的研究进展过程,包括模型的提出、修正、改进和扩展,同时指出了不同模型的适用范围。介绍了模型在各种复杂电解质溶液体系关联计算中的应用,可以为一些工业生产过程的模拟、设计和优化提供理论指导。电解质NRTL模型的主要优势是适用的温度和浓度范围宽,不需二元以上高阶参数;但模型自身也存在缺陷,如参数的回归工作量大、在溶液体系临界点处的预测精度较差等,故模型仍需进一步完善。 相似文献
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Pramil C. Deb 《Polymer》2007,48(17):4932-4935
Method of determination of penultimate model reactivity ratios has been generalized to take care of specific systems where copolymer composition data are available only in narrow ranges. A number of copolymerization systems reported in literature have been analyzed and applicability of generalized relationship was tested. Most systems are seen to follow penultimate model better than the terminal model. Monomer independent universal relationship of penultimate model reactivity ratios has similarly been generalized and successfully tested. 相似文献
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A drug release mechanism is combined with a Compartmental Absorption and Transit (CAT) model within a pharmacokinetic framework for predicting orally administered drug release and transport. The developed model is used to evaluate pharmacokinetic metrics such as peak plasma concentration, area under the curve (AUC) and bioavailability. A comparative study has been performed on different cimetidine tablet formulations for which clinical drug profiles are available for model validation. The model predictions are in good agreement with the clinical results. Different scenarios based on induced changes in average patient body weight, fraction of drug in the tablet, tablet radius and their corresponding effects on the model predictions are discussed. The change in average patient body weight has a low effect on the plasma concentration profile while the fraction of drug in the tablet has a strong effect. In a scenario study within an optimization framework, the model has been able to determine the optimal dimensions of a tablet of fixed dosage in order to obtain maximum therapeutic effect from the tablet. 相似文献
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