Kinetics of phenol oxidation in a trickle bed reactor over active carbon catalyst

The wet air oxidation of phenol over a commercial active carbon catalyst was studied in a trickle bed reactor (TBR) in the temperature and oxygen partial pressure ranges of 120–160 °C and 0.1–0.2 MPa, respectively. The performance of the active carbon was compared in terms of phenol and COD destruction. The weight change of active carbon due to reaction was also measured. Finally, oxic phenol adsorption isotherms were assessed in batch conditions at 25, 125 and 160 °C. In order to use the conversion data obtained from the TBR for a kinetic study, special care was taken to check the kinetic control in the TBR experiments. Several kinetic models including power law or Langmuir–Hinshelwood expressions were considered to describe the catalytic oxidation of phenol over active carbon. The simple power law model with first order dependence on both phenol and oxygen concentration predicted satisfactorily the experimental data not only over the entire range of operating conditions studied, but also outside its validity range. Copyright © 2005 Society of Chemical Industry     

利用扫描电镜研究三维电极主电极表面腐蚀状况

借助扫描电镜（SEM）对不同实验条件下的三维电极主电极表面腐蚀状况进行研究。结果表明，三维电极主极阳极的内侧腐蚀程度远大于其外侧，水样性质、电极材料性质对电极的腐蚀程度有很大的影响，不锈钢做三维电极主电极优于铝、铁电极。为三维电极主电极的选材提供了一定的理论依据。     

R－X图解法计算多级串联理想混合反应器

论述Ｒ－Ｘ图解法计算多级串联理想混合反应器的基本原理，并结合实例，对Ｒ－Ｘ法的计算步骤予以详细介绍，为多级串联反应器的设计与计算，提供一种新颖适用的图解计算方法。     

Analysis of low load transients for the Vandellòs-II NPP: Application to operation and control support

The Technical University of Catalonia (UPC) has been jointly working with the Asociación Nuclear Ascó-Vandellòs (ANAV) for a number of years in order to establish, qualify and use best estimate (BE) models for the reactors under the control of ANAV. ANAV is the consortium that is responsible for operation of the Ascó and Vandellòs-II reactors. The reactors are Westinghouse-design three-loop PWRs with an approximate electrical power of 1000 MW. The existing integral plant models for each plant are currently used for many different purposes among which are support of plant operation and control. Quite a number of studies have been done in order to improve both safety and plant competitiveness. Most of these dynamic analyses were carried out in relation to transients starting at nominal full power or at least, very close to full power. This paper develops a specific use of the Vandellòs-II plant model for operation and control support at low power involving new ranges of system actuation parameters. It also examines scenarios that are somewhat different from those typically analysed. The study starts showing the results of an assessment case, which is a start-up test and provides some additional qualification, and subsequently attempts to establish calculations to support both an improvement in feed water controls and to set up operating recommendations for low-load manual operation of feed water turbo-pump. Both results hopefully, will produce an outcome, which leads to an improvement in safety and reduces reactor trip probability.     

我国核裂变能可持续发展战略研究

本文从科学技术的角度,分析我国国民经济增长对核能发展的需求,探讨我国核能的近中期发展战略构想,指出为实现其发展战略目标而应重点研究的关键科学技术与问题,并提出一些相关的政策建议,为国家制定核能中长期发展规划提供参考。     

中空纤维酶膜反应器及其动力学初步探讨──Ⅰ．单酶系统中空纤维酶膜反应器

单酶系统中空纤维酶膜反应器是用天津纺织工学院研制的ＴＦＣ－００３型聚砜中空纤维超滤器固定β－淀粉酶，在一定条件下催化可溶性淀粉制取麦芽糖的反应器。试验中，对温度、ｐＨ、酶及底物浓度变化动力学参数进行了初步探讨，试验重复性好。     

SIMULATION OF MICROMIXING IN A TURBULENT TUBULAR REACTOR WITH CONCENTRIC FEED

Turbulence on the axis of a pipe is isotropic and homogeneous and the rate of turbulent energy dissipation, ε, is known as a function of the velocity, pipe diameter and viscosity. When, however, a concentric feed pipe is introduced (as in a reactor), the ε field does not seem to be known. Evidence from fast, mixing-controlled reactions indicates a disturbance near to and downstream from the feed pipe with an increase in ε. Because of the lack of experimental information, the radial and axial distribution of ε has been modeled. One parameter—ε at the outlet of the feedpipe—is undetermined in this model. It is shown how the radial dispersion and especially the micromixing and reaction of fluid emerging isokinetically from the feed pipe can then be calculated, using a one-dimensional, radially averaged formulation. An application to four coupled, mixing-controlled reactions is included. Simulated and measured product distributions compared satisfactorily at various concentration levels and two solution viscosities. Whereas the new model is plausible, more work is needed to understand how a feed pipe modifies the flow in its vicinity.     

德国艾柯夫SL-500采煤机变频器故障及分析

晋城煤业集团引进德国艾柯夫SL-500采煤机,在使用过程中,短时间内连续出现多台变频器烧坏现象,这在艾柯夫采煤机使用过程中是从未有过的事,也给本公司的原煤生产造成了很大影响。为了杜绝此类事情的再次发生,特对本次的故障排除方法进行了认真的分析总结,为今后应用与修理采煤机提供了意见。     

Theoretical investigation on the steady-state natural circulation characteristics of a new type of pressurized water reactor

1 Introduction With respect to the inherent safety of nuclear re- actors, application of passive systems/components including natural circulation phenomena as the main mechanism is intended to simplify the safety-related systems and to improve their reliability, to reduce the effect of human errors and equipment failures, and to provide more time to enable the operators to prevent or mitigate serious accidents. Natural circulation is the main mode of heat removal for removing decay heat from t…     

反应堆堆芯围筒结构热流固耦合热变形分析

针对反应堆堆芯围筒热流固耦合问题,采用三维有限元法研究堆芯围筒的热变形.考察ANSYS的三维实体热单元SOLID 70,三维实体单元SOLID 45,三维表面热效应单元SURF 152和三维热-流耦合管单元FLUID 116等单元类型的特点和实用性.建立堆芯围筒、吊篮和冷却剂的温度分析有限元模型：堆芯围筒和吊篮采用SOLID 70,结构表面与冷却剂的对流传热表面采用SURF152,堆芯围筒与吊篮之间冷却剂采用FLUID 116.采用SOLID 45建立堆芯围筒有限元模型,根据得到的堆芯围筒、吊篮和冷却剂的温度场结果分析堆芯围筒热变形.结果表明,在考虑堆芯围筒及吊篮固体和流体的交叉耦合的基础上,采用三维有限元法能比较客观地模拟反应堆堆芯处的复杂运行环境.