Application of boundary element method to 3-D problems of coupled thermoelasticity

This paper deals with a new boundary element method for analysis of the quasistatic problems in coupled thermoelasticity. Through some mathematical manipulation of the Navier equation in elasticity, the heat conduction equation is transformed into a simpler form, similar to the uncoupled-type equation with the modified thermal conductivity which shows the coupling effects. This procedure enables us to treat the coupled thermoelastic problems as an uncoupled one, A few examples are computed by the proposed BEM, and the results obtained are compared with the analytical ones available in the literature, whereby the accuracy and versatility of the proposed method are demonstrated.     

模块化蓝光光存储性能静态测试系统

蓝光光存储是信息存储领域发展的一个重要方向。测试系统是研究蓝光光存储材料的必备条件，为建立蓝光光存储研究平台，设计和搭建了一套模块化蓝光光存储性能静态测试系统。激光工作波长为406．7nm。系统采用调制解调技术降低系统噪声，提高测量粘度：采用光点移动模式降低对样品尺寸的要求；采用纳米平台提高记录点的反复定位性能。实验结果证明测试系统性能良好，可以满足蓝光光存储性能静态测试要求。     

建筑围护结构与节能

针对我国夏热冬冷地区的建筑气候特点,对建筑围护结构节能在设计中的要点和意义进行了讨论。     

NUMERICAL STUDY ON SORET-EFFECT AND DUFOUR-EFFECT FOR DOUBLE-DIFFUSIVE NATURAL CONVECTION IN POROUS ENCLOSURE

The influences of Soret effect and Dufour effect on the natural convection and heat and mass transfer for a porous enclosure were investigated by means of the penalty finite element method. Numerical results indicate that the Soret and Dufour effects have significant influences on heat and mass transfer in the presence of large temperature gradient and concentration gradient.     

Interconnected power systems with superconducting magnetic energy storage

The objective of this work is to discuss the concept of back‐to‐back interconnection systems with energy storage, especially with a Superconducting Magnetic Energy Storage (SMES) incorporated into a back‐to‐back DC link. In this case, each converter of the back‐to‐back system is used as a power conditioning system for the SMES coils. Since the AC–DC converter can be designed independently of the frequency of the power system, a two‐way switch is connected to the AC side of each converter. This two‐way switch can select the interconnected power systems. By using the two‐way switches, this system can provide the stored energy in the SMES system to each interconnected power system through two AC–DC converters. For instance, lower‐cost power of each power network can be stored through two converters during the off‐peak hours and made available for dispatch to each power network during periods of demand peak. Then this system increases the reliability of electric power networks and enables the economical operations depending on the power demand. This paper describes the unique operations of the back‐to‐back interconnection with SMES and discuses the optimal SMES configuration for a 300‐MW‐class back‐to‐back interconnection. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 164(2): 37–43, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20482     

大型压力容器现场热处理技术

以大连石化350万t/a催化裂化装置再生器为例,研究开发大型炼油化工设备现场新型热处理工艺。通过设置必要的热气流导向装置,采用微正压内燃工艺,配备新型大功率燃油喷嘴、用DCS集散控制系统调节油风比例和烟囱热量排放张合度,对超厚壁板适当增加电加热辅助热处理,解决了大容积、变截面、不等壁厚、超重设备施工现场热处理温度调整难度大、不均衡等技术问题。实践证明,应用该技术进行热处理,具有工期短、效果好、经济效益明显等特点。     

疏水缔合型聚丙烯酰胺的合成与性能评价

为了提高高相对分子质量的聚丙烯酰胺的抗温抗盐性能,利用自制的两亲表面活性单体与丙烯酰胺共聚合成了疏水缔合型聚丙烯酰胺并进行室内评价。结果表明,在高温、高盐、高钙条件下,合成的疏水缔合型聚丙烯酰胺具有良好的增粘性和较强的热稳定性;克服了疏水缔合型聚合物在盐水中溶解性差的问题,可用各种矿化度的盐水和油田产出污水配制;具有良好的无机盐增粘性能和抗温性能。     

Time‐dependent heat transfer coefficient of a wall

A time‐dependent coefficient of heat transfer is proposed for the computation of thermal power required, so that a room temperature reaches a desired value within a given time. A mathematical formulation of the room heating transient phenomenon is constructed in a dimensionless form. Using an integral approximate solution an analytical expression for this coefficient is provided and it is verified by diagrams adopted by DIN 4701. Copyright © 2003 John Wiley & Sons, Ltd.     

Optimum thermoeconomic and thermodynamic performance characteristics of an irreversible three-heat-source heat pump

The coefficient of performance and specific heating load of an irreversible three-heat-source heat pump are given by using a general cycle model affected by the finite-rate heat transfer, heat leak and internal irreversibility of the cyclic working fluid. The heat pumping load divided by the total cost per unit time is taken as a new objective function and used to investigate the performance of the heat pump. The thermoeconomic and thermodynamic performance characteristics of the heat pump are discussed in detail. Some important performance parameters such as the thermoeconomic objective function and coefficient of performance are optimized. The optimally operating regions of the heat pump and the bounds of several performance parameters are determined. Finally, it is pointed out that the Carnot heat pump may be taken as a special case of a three-heat-source heat pump and consequently its optimal performance can be directly derived from the results obtained here.     

石油价格机制改革之对策

文章在阐述我国石油价格形成机制的演变过程的基础上,针对我国目前石油定价机制所导致的诸如石油价格变动滞后以及由此带来的市场信号失灵等问题思考了相应的改革对策,提出了调整政府价格管理职能、建立平等竞争的市场规则、完善稳定油价的调控体系以及加快建立石油战略储备等7个方面的建议。