一种通用型喷油器的改进设计

本文介绍了一种通用型喷油器总成的改进与应用。通过产品的批量生产和在发动机上的试验验证,改进后的喷油器可以与改进前的喷油器互换,其产品具有良好的通用性,达到了节约成本、宜批量组织生产的目的。     

Process analysis of direct laser melting to fabricate layered hybrid beads

The successful fabrication of layered hybrid beads by DLM process is limited by dissimilar melting ranges of different powders.For the application of DLM process into manufacturing industries,target mechanical properties of final product must be achieved.Process analysis was performed for the DLM fabrication of layered hybrid beads by using stainless steel (SS 316L) and titanium powders.For the analysis of fabrication characteristics,single hybrid bead was formed using SS316L powder onto the base plate and then Ti powder was melted onto the previous melted layer.In addition,multi-layer hybrid beads were fabricated for the analysis of the layering effects between them.From these studies,the effects of the processing parameters,such as laser power,scan rate and scan line spacing on surface morphology were characterized and optimum processing conditions for the DLM fabrication of layered hybrid beads were developed.     

化学吞吐技术在超深稠油井的应用

针对鲁克沁超深稠油油田低产低效井进行系统分析,调研并优选新型化学吞吐剂,经过优化施工工艺设计,现场实施6井次,平均单井增产大于600 t,取得了较好效果。矿场试验表明,化学吞吐技术是鲁克沁油田稠油井增产的一种有效方式,具有一定的推广及应用前景,对同类油田的开发具有一定的指导意义。     

不同形貌节理对应力波传播影响的数值模拟

用3DEC离散元软件对一维正弦纵波在无节理有限长及有一节理有限长岩杆中的传播进行标定,确定建模的单元网格尺寸、边界条件等参数。然后对一维正弦纵波在含量化的不同粗糙度节理面的岩杆中传播进行数值模拟,探究应力波穿过不同形貌特征的节理时的透反射规律。分析模拟结果发现:节理面粗糙度JRC值相同,相对节理初始法向刚度不同时,随着刚度系数的增加,透射过节理面的应力波越多,在α0.5时,透射系数值增加较快;在α0.5时,透射系数值增加较慢,逐渐趋近于1。同一刚度系数α值下,随着节理粗糙度JRC值的增加,透射系数增大,当α1.5时,透射系数趋于稳定。     

鞍钢鲅鱼圈4038m~3高炉喷煤生产实践

对鞍钢鲅鱼圈2座4038 m~3高炉的喷煤工艺流程的特点和富氧喷煤生产情况进行了总结。2座高炉经过一段时间的运行,煤比稳定在170kg/t以上,高炉生产稳定顺行,达到了设计要求。     

RAPID SOLIDIFICATION OF SUBCOOLED SMALL METALLIC DROPS

Accurate rapidly and slowly varying analytical solutions are obtained for the problem of the rapid solidification by convection of subcooled small metallic drops. These solutions, which were suggested by the approximate results obtained by using a quasi-moving-boundary approach, are useful in estimating metallurgical parameters in rapid rate solidification technology.

The rapidly varying regular perturbation solution describes recalescence during which the liquid core increases very quickly from the nucleation temperature to the melting point. Enormous internal heat transfer rates dominate the process, and the solid-liquid interface is morphologically unstable, during recalescence. External convective heat transfer dominates after recalescence, and the slowly varying solution shows that this period begins when the dimensionless thickness of the solidified region is approximately equal to 1 ? (1 ? S)^1/3. The position of the interface after recalescense is given by (1 ? S ? 3Hθ)^1/3

Complete freezing of the droplets occurs at time t = (R²/α₁)(1 ? S)/3H. The time required for recalescence is on the order of microseconds and is usually only a small fraction of the total freezing time.     

相转移催化法合成糖苷类化合物的研究进展

相转移催化法具有操作简便,反应速度快,反应条件温和,后处理简单和立体选择性强等优点。近年来相转移催化法广泛应用于糖苷类化合物的合成。综述了相转移催化法所用的各类相转移催化剂(季铵盐类、叔胺类等)在糖苷类化合物合成中的应用,指出季铵盐类催化剂应用最为广泛。