炼油厂酮苯脱蜡装置空冷器腐蚀失效分析

独山子石化公司炼油厂酮苯脱蜡装置空冷器因空冷管束(20号钢)腐蚀穿孔被迫停工检修,经取样分析和现场调查,结果表明:溶解氧含量偏高、设备本身存在震动、无盐水质量不稳定以及空冷管束选材不当是造成空冷器管束腐蚀穿孔的主要原因。在冷却用水中加入水处理药剂或选用OCr13等耐蚀材质的管束以及减小震动磨损等措施可减少空冷器管束腐蚀穿孔。     

Development of Systems for Ball Cleaning of Condensers and Experience of Their Operation

The development of a method for cleaning steam turbine condenser tubes with the help of porous rubber balls (Taprogge Company, Germany) by Russian specialists is presented. The filter for extra cleaning of the cooling water suggested by the VTI forms an autonomous system of water cleaning, which eliminates contamination of the water chambers and tube boards of the condenser.     

Experimental investigation of falling film evaporation on horizontal tubes

This paper presents the results of an experimental investigation relating to heat transfer during evaporation of thin liquid films falling over horizontal tubes. Experiments were conducted using 25 mm o.d. copper tubes heated by internal electrical cartridge heaters so that a uniform heat flux was generated on the outside tube surface. Five heated tubes were arrayed on a vertical plane with a pitch of 50 mm. Freon R-11 preheated to the saturation temperature at 0.2 MPa was supplied to the topmost heated tube through feeding tubes. Heat transfer characteristics on each heated tube were clarified in a range of film Reynolds number from 10 to 2000 and the measured data are presented in the form of correlations. Deterioration of heat transfer due to film break down was also considered. © 1999 Scripta Technica, Inc. Heat Trans Jpn Res, 27(8): 609–618, 1998     

一种高效热交换用管——内、外螺旋管的加工技术

介绍一种高效热交换用管———内、外螺旋线管的生产方法及其高效传热机理。介绍旋轧成形机和工模具之间的安装结构 ,翅片管成形时各旋轧辊的配置情况。运用本方法 ,用普通光管可一次成形加工出高效热交换用管。     

一种轻质RF馈线的研制及应用

介绍了一种新型的轻质RF馈线,可以作为铜质传输馈线的替代品,用在移动通信基站系统以及其它无线通信系统中作为传输介质,给用户提供另一种可选的传输产品。     

套管式地下换热器传热模型及其特性分析

通过对套管式地下换热器传热过程的分析,在已有套管式地下换热器传热模型基础上,考虑管内流动和传热,提出了集管内流动与土壤导热相耦合的传热分析模型,并利用有限元数值计算方法进行了传热特性的分析。讨论了埋管管径组合和流体流速对流体出口温度及单位埋管换热量的影响。此外,还系统地研究了连续运行模式和可变负荷运行模式的地下传热特性,阐述了地下换热器高效运行的控制策略和影响。     

Diffusion through ordered force fields in nanopores represented by Smoluchowski equation

The classical Einstein or Fick diffusion equation was developed in random force fields. When the equation is applied to gas transport through coal, significant discrepancies are observed between experimental and simulation results. The explanation may be that the random force field assumption is violated. In this article, we analyze molecular transport driven by both random and ordered (directional) forces in nanopores. When applied to CO₂ transport through cone‐shaped carbon nano‐tubes (CNTs) and Li⁺ doped graphite pores, computational results show that directional force fields may significantly affect porous media flow. Directional forces may be generated by potential gradients arising from a range of non‐uniform characteristics, such as variations in the pore‐sizes and in local surface compositions. On the basis of the simulation and experimental results, the Smoluchowski and Fokker‐Planck equations, which account for the directional force fields, are recommended for diffusion through ordered force fields in nanopores. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

锅炉四管泄漏原因分析及改造方案

分析了大唐鸡西热电有限责任公司现有两台HG--420／13．7-YM3型锅炉四管泄漏原因,通过对锅炉进行校核计算,提出了改造方案。     

超超临界锅炉受热面管角变形对应力的影响

角变形是电站锅炉受热面管子安装过程中常见的缺陷,严重的角变形不仅影响传热,而且会降低管子的使用寿命。本文针对超超临界锅炉水冷壁管,分别模拟了管子不发生角变形及角变形为1％、3％、5％的4种情况下的应力分布情况,结果表明角变形会引起焊缝区域的应力集中,且角变形越严重,应力集中情况越明显。     

Current–Voltage Characteristics in Individual Polypyrrole Nanotube, Poly(3,4-ethylenedioxythiophene) Nanowire, Polyaniline Nanotube, and CdS Nanorope

In this paper, we focus on current–voltage (I–V) characteristics in several kinds of quasi-one-dimensional (quasi-1D) nanofibers to investigate their electronic transport properties covering a wide temperature range from 300 down to 2 K. Since the complex structures composed of ordered conductive regions in series with disordered barriers in conducting polymer nanotubes/wires and CdS nanowires, all measured nonlinear I–V characteristics show temperature and field-dependent features and are well fitted to the extended fluctuation-induced tunneling and thermal excitation model (Kaiser expression). However, we find that there are surprisingly similar deviations emerged between the I–V data and fitting curves at the low bias voltages and low temperatures, which can be possibly ascribed to the electron–electron interaction in such quasi-1D systems with inhomogeneous nanostructures.