焦炭热态性质预测模型的研究

采用干燥无灰基挥发分(Vdaf)、粘结指数(G)、灰分(A)、炭化室高度与宽度(LB)为自变量,对焦炉实际生产数据进行回归分析,结果表明,回归效果良好。在焦炭质量预测模型公式中增加焦炉炉型特征参数LB,建立的预测焦炭热态性质V-G-A-LB模型与常规V-G-A模型相比,预测准确度高,更具有合理性和实际应用价值。

提高焦炭热态性质的因素分析

论述了高炉大型化是中国钢铁工业发展的必然趋势,对影响焦炭热态性质的各种因素(如微观强黏比、堆比重、熄焦方式、灰分、灰成分、结焦时间等)进行分析,为焦化企业在提高焦炭热态性质方面提供参考。

反应堆压力容器保温层辐射屏蔽组件传热计算分析及屏蔽材料试验研究

目的确保华龙一号HPR1000反应堆压力容器保温层辐射屏蔽组件在运行工况下的可靠性、安全性以及能够有效执行其功能。方法采用基于传热理论结合经验公式的理论计算方法,以及流固耦合的有限元仿真分析,对辐射屏蔽组件的运行温度进行计算。针对屏蔽材料在受热状态下的性质变化,进行一系列的热态性质试验。结果理论计算方法得到的结果为163.36~168.74℃,有限元仿真分析得到的结果为236.85~266.85℃,两者偏差约100℃。对造成该种差异的原因进行了分析,发现仿真分析方法得到的结果的置信度更高。屏蔽材料在受热状态下,其体积膨胀率可达到38.82%,而当屏蔽材料受热超过其温度限值204℃后,将出现明显的粉化等物理状态恶化的趋势。结论流固耦合的有限元仿真分析方法更适用于辐射屏蔽组件的传热过程计算,同时获取了屏蔽材料物理性状受热变化趋势,对屏蔽组件的选材及结构设计具有指导意义。

抑制焦炭劣化技术研究进展

总结了抑制焦炭劣化技术研究现状,重点介绍了硼酸、硼系复合抑制剂和有机热解炭抑制焦炭劣化技术的抑制效果、影响因素、抑制机理、经济性和环境影响以及工业化水平。探讨了抑制焦炭劣化技术现存问题、待研课题和发展方向。

Comparison of mechanical properties in high temperature and thermal treatment granite

Static mechanical experiments were carried out on granite after and under different temperatures using an electro-hydraulic and servo-controlled material testing machine with a heating device. Variations in obvious form, stress-strain curve, peak strength, peak strain and elastic modulus with temperature were analyzed and the essence of rock failure modes was explored. The results indicate that, compared with granite after the high temperature treatment, the brittle-ductile transition critical temperature is lower, the densification stage is longer, the elastic modulus is smaller and the damage is larger under high temperature. In addition, the peak stress is lower and the peak strain is greater, but both of them change more obviously with the increase of temperature compared with that of granite after the high temperature treatment. Furthermore, the failure modes of granite after the high temperature treatment and under high temperature show a remarkable difference. Below 100 ℃, the failure modes of granite under both conditions are the same, presenting splitting failure. However, after 100 ℃, the failure modes of granite after the high temperature treatment and under high temperature present splitting failure and shear failure, respectively.

INTERFACIAL BONDING IN AS DEPOSITED AND ANNEALED Co/C SOFT X RAY MULTILAYER MIRRORS

Interfacial bonding in as deposited and annealed Co/C soft X ray multilayer structures is investigated by X ray photo electron spectroscopy (XPS).It is found that there is interdiffusion between cobalt and carbon in the as deposited Co/C multilayers,and this is confirmed by structure characterization using low angle X ray diffraction (LAXD).The calculation of the chemical shifts in Co C system based on Miedemas macroscopic atom model suggests that it is impossible to detect the chemical shift experimentally in the Co C compound,which is consistent with the XPS results.The presence of metallic carbide bonding is evidenced through the nature of the carbon bonding in survey taken at Co C and C Co interfaces of annealed samples.Our results also indicate that XPS is a direct method to probe the chemical bonding at the interfaces.

淮南望峰岗精煤结焦特性研究

介绍了针对淮南望峰岗和其它地区的几种1/3焦煤进行的20 kg小焦炉试验。试验结果表明,望峰岗精煤可显著提高焦炭的反应后强度,降低反应性,热态性质优势明显。

Statistical mechanics and artificial intelligence to model the thermodynamic properties of pure and mixture of ionic liquids

In this paper, the volumetric properties of pure and mixture of ionic liquids are predicted using the developed statistical mechanical equation of state in different temperatures, pressures and mole fractions. The temperature dependent parameters of the equation of state have been calculated using corresponding state correlation based on only the density at 298.15 K as scaling constants. The obtained mean of deviations of modified equation of state for density of all pure ionic liquids for 1662 data points was 0.25%. In addition, the performance of the artificial neural network(ANN) with principle component analysis(PCA) based on back propagation training with28 neurons in hidden layer for predicting of behavior of binary mixtures of ionic liquids was investigated. The AADs of a collection of 568 data points for all binary systems using the EOS and the ANN at various temperatures and mole fractions are 1.03% and 0.68%, respectively. Moreover, the excess molar volume of all binary mixtures is predicted using obtained densities of EOS and ANN, and the results show that these properties have good agreement with literature.

One-Parameter Equation of State for Gases and Gas Mixtures

The simplest equation of state that can be applied to calculate the thermodynamic properties of gases is the virial equation with the second coefficient B. The probability of applying the one-coefficient equation Z = exp(A/V) for the calculation of compressibility factor at critical temperature of gases and gas mixtures is investigated. It was verified that the one-coefficient equation of state can be applied to calculated the thermodynamic properties for both normal and strongly polar gases and gas mixtures.

Unique influences of reboiler inventory control on the operation of totally reboiled reactive distillation columns

In this work,the dynamics and operation of the totally reboiled reactive distillation columns are visualized in terms of transfer function based process models.This kind of processes is found to be characterized by underdamped step responses due to the special topological configuration and the intricate interplay between the reaction operation and the separation operation involved.The under-dampness can be substantially alleviated through the tight inventory control of bottom reboiler and this presents beneficial effects to process dynamics and operation.Two totally reboiled reactive distillation columns,separating,respectively,a hypothetical synthesis reaction from reactants A and B to product C,and a real decomposition reaction from 1,4-butanediol to tetrahydrofuran and water,are employed to demonstrate these uncommon behaviors.The results obtained give full support to the above qualitative interpretation.Despite the strong influences of reaction kinetics and thermodynamic properties of the reacting mixtures,the totally reboiled reactive distillation columns are generally considered to present such unique behaviors and require tight inventory control of bottom reboiler to facilitate their control system development.

A Statistical Mechanical Equation of State for Fluid UF4 and ThF4

Uranium tetrafluoride, UF4, and thorium tetrafluoride, ThF4, can be used as fuels in molten salt reactors. For the molten salt reactor design and safety analysis, it is essential to know the thermodynamic properties of the UF4 and ThF4 materials. However, the experimental data for UF4 and ThF4 P-V-T are scarce in literature. Under this circumstance prediction of the thermodynamic properties can be supported by theoretical calculations to remedy missing experimental data. Within this paper the Song, Mason and lhm＇s equation of state with modification of Tao and Mason, originally derived for spherical and molecular fluids, is applied for fluid UF4 and ThF4 based on the available experimental data. The equation of state is based on statistical mechanical perturbation theory with the perturbation scheme of Weeks, Chandler, and Andresen. The prediction of constants applied in the equation of state is based on the work of Boushehri et al. using data for heat of vaporization and liquid density at the triple point. The calculation of the heat of vaporization applies the ＂sigma＂ method reported by Darken et al. with the vapour pressure data and heat capacities of liquid and vapour of UF4 and ThF4. Finally an extra correction term for the vapour pressure is introduced into the new equation of state. The results show that this equation of state agrees reasonably well with the available experimental data. It can be expected that this equation of state can be applied also for conditions where experimental data are currently missing.