苏里格气田树枝状采气管道的吹扫试压

苏里格气田采用中低压集气模式,采气管道为树枝状串接,长庆石油勘探局建设工程总公司根据树枝状管网的特点,总结出了一套对树枝状管网进行吹扫试压的方法,采用了逐条吹扫、整体试压的方式,既经济又顺利地完成了树枝状管网的吹扫试压工作。文章介绍了管道吹扫试压的具体做法,并提出了安全措施。采气管道投产后,未发生质量和安全问题,达到了预期的效果。     

Effects of nano-alumina content on the formation of interconnected pores in porous purging plug materials

The physical properties and microstructure of porous purging plug materials added with different nano-alumina contents and firing temperatures were investigated by means of X-ray diffraction, scanning electron microscopy, air permeability, pore size distribution, mean pore size, apparent porosity, bulk density, and cold crushing strength (CCS) tests. The results showed that the addition of nano-alumina had a great effect on the physical properties and microstructure of the porous purging plug materials. With increasing nano-alumina content in the composition, the main phase was α-Al₂O₃ in all compositions and the mean pore size, apparent porosity and air permeability all increased due to the increased number of pores and pore size of the specimens which facilitated the formation of interconnected pores. When the sintering temperature was changed from 1550 °C to 1650 °C, some of the smaller pores vanished due to solid phase sintering, which reduced the apparent porosity, and some open pores connected to form interconnected pores, which promoted increased air permeability. In addition, the strength and porosity were found to follow the relationship σ = σ₀ exp (-b P). When the apparent porosity increased, the CCS decreased, and vice versa.     

1420mm冷轧机组吹扫器对钢带质量的影响

通过改进1 420 mm冷轧机组吹扫器结构,使钢带表面的乳化液斑、黑带明显减少,提高了钢带的表面质量。     

水泥加入量对刚玉-尖晶石质钢包透气砖座砖性能的影响

以粒度6~3、3~1、≤1 mm的板状刚玉颗粒为骨料,粒度≤0.074 mm的板状刚玉和烧结尖晶石细粉为基质,活性α-Al2O3微粉、纯铝酸钙水泥为结合剂,聚丙烯纤维、偶氮甲酰胺、碳酸氢钠及聚丙烯纤维+碳酸氢钠为防爆剂,制备了刚玉-尖晶石质钢包透气砖座砖,研究了水泥加入量(质量分数分别为2%、4%、6%、8%和10%)对透气砖座砖常温性能、抗热震性和抗爆裂性能的影响。结果表明:随着水泥加入量的增加,110℃干燥后常温强度增加,1 560℃烧后常温强度、显气孔率和线变化率先增加后降低;水泥加入量6%(w)时试样的强度最低,显气孔率和线变化率最大,其常温性能最差;随着水泥加入量的增加,1 100℃水冷3次后试样的强度保持率增加,抗热震性能改善,水泥加入量为10%(w)时抗热震性最好;采用碳酸氢钠或碳酸氢钠+聚丙烯有机纤维复合的防爆剂试样的抗爆裂效果最好。研制的透气砖座砖在150 t转炉钢包上使用,寿命由原来的平均31次提高到平均36次。     

防尘装置在发电厂高含尘风量测量中的应用

通过配套在线吹扫装置进行技术改造,彻底解决空预器漏风带尘造成的均速管流量计均速管探头堵灰现象,保证了流量计的精确测量。     

Effect of air purging and dry operation on durability of PEMFC under freeze/thaw cycles

The effect of air purging and dry operation on durability of polymer electrolyte membrane fuel cell (PEMFC) under repeated freeze/thaw cycles between −20 °C and 60 °C was investigated. The cathode air purging and the operation with dry air feed were highly effective to mitigate freeze damage. The removal of the air purging of the anode compartment did not lead to the degradation of the anode catalyst layer. It is of practical importance, because the air purging of the anode could cause carbon corrosion of the cathode. The performance degradation by the freeze/thaw cycles was associated with the increased charge transfer and mass transfer resistances. After the freeze/thaw cycles, any discernable morphological changes were not observed in the scanning electron microscopic images of the anode, the membrane and the membrane/electrode interface, however, mechanical damage of the poly(tetrafluoroethylene) phases in the cathode diffusion layer was detected.     

西宁特钢10m2球团竖炉配料膨润土除尘器系统改造

通过对10 m2竖炉球团生产线上膨润土集中布袋除尘系统新增微油螺杆压缩机,将其产生的高压气体用于输送膨润土除尘灰到膨润土配料仓,节省了倒运膨润土除尘灰的运输成本,解决了布袋吹扫使用氮气成本高的问题,同时减轻了环境污染.     

Detailed Modeling of Gas Flow in Liquid Steel: Bubble Size Distribution and Voidage Calculation

Although the role of gas purging in liquid steel systems is well recognized, it has yet to be adequately analyzed. One key aspect of this process is the prediction of gas voidage in the bath, which has been studied in great detail beginning with water modeling in the early days and using advanced multiphase models more recently. Still, there are significant unresolved issues with gas purging systems. When gas is introduced through a nozzle at high flow rate, a jet may form which is undesirable. The break‐up of this jet into bubbles is a separate topic of research. The more common practice in the steel industry is to use porous plugs for gas injection. Gas entry through a porous plug can be characterized by the stretched bubble regime, and the laws of coalescence and fragmentation used to analyze bubble column reactors are generally applicable. Calculation of the bubble size distribution is important for two reasons. First, the voidage distribution in the bath is significantly modified by the injection system and flow rates used, primarily due to changes in flow regime and bubble dynamics (collision, break‐up, coalescence). Second, the voidage distribution directly determines the buoyancy, that influences the physical mixing process, and the specific‐area‐density, that influences surface reactions (for example, decarburization, desulfurization and nitrogen pick‐up). In this paper, a numerical study is presented that combines a bubble dynamics model with an Eulerian multiphase model. The results of the simulation are compared with the experimental data from Anagbo and Brimacombe (1990). Relevant discussion and reviews will be presented to distinguish the differences of this detailed bubble dynamics model with the uniform bubble diameter approximations reported in various recent studies.     

高纯氯生产技术的推广应用及发展

概述高纯氯的研制及其科研成果推广应用的发展动态。     

基于变压吸附制氮系统的BOG再冷凝工艺

为了解决LNG接收站在低输量工况下闪蒸气(Boil-Off Gas,以下简称BOG)回收不完全的问题,在不增加冷凝工艺复杂性的前提下,基于现有设备的实际工况及工艺流程,以热力学原理、静态仿真计算结果为依据,在传统的蓄冷式BOG冷凝方案的基础上,结合LNG冷能利用方式,提出了一种基于LNG接收站制氮系统的蓄冷回收BOG新工艺,并进行了BOG温度、冷凝器入口压力、LNG组分等参数的敏感性分析,明确了新工艺的适用条件。运用效果表明:(1)新工艺充分利用了LNG接收站的现有设备,每年可为LNG接收站节能创收近160万元;(2)新工艺可实现高负荷下的BOG冷凝,其冷凝外输工艺可作为辅助冷凝工艺,冷凝回罐工艺可作为应急工艺——液氮用于蓄冷、气氮用于吹扫,可满足接收站的多种需求;(3)较之于前人提出的4种BOG处理工艺(多级压缩、级间冷却、预冷和透平回收轴功),新工艺在对外输量的依赖性、流程安全性及操作性等方面均有优势。结论认为:新工艺在设备投资、能耗、工艺安全性及经济效益上都具有明显的优势,值得推广应用。