The effect of the blockage ratio on the blow-off limit of a hydrogen/air flame in a planar micro-combustor with a bluff body

We recently developed a micro-combustor with a bluff body, which has a demonstrated 3- to 5-time extension in the blow-off limit. In the present work, the dimension effect of the bluff body on the blow-off limit (indicated by the blockage ratio, ζ) was investigated with a detailed H₂/O₂ reaction mechanism. The results indicate that the blow-off limits for ζ = 0.3, 0.4 and 0.5 are 20, 31 and 36 m/s, respectively. Analyses reveal that for ζ = 0.3, flame blowout occurs due to insufficient recirculation zone size. However, flame blowout occurs due to the stretching effect in the shear layers when ζ = 0.4 and 0.5. Calculations indicate that the three cases have negligible differences in heat loss because the high temperature zones are located in the combustor centers; therefore, their effects on the combustor walls are mitigated.     

Dependence of the blowout limit on flow structure,heat transfer,and pressure loss in a bluff-body micro-combustor

In this study, we numerically investigated the main factors affecting the flame blowout limit of bluff-body micro-combustors with a blockage ratio (δ) varying from 0.3 to 0.8; the combustion performance of these combustors is investigated as well. Measurements from the literature (Fan et al., 2012, Int J Hydrogen Energy, 37, 19,190–19,197) were used to validate the present numerical models. The predicted results are in good agreement with the experimental data, with a relative error of less than 10%. The results show that the blowout limit increases with δ in a non-monotonic manner. The establishment of a low-velocity recirculation behind the bluff body and recirculation of heat and key radicals help increase the flame blowout limit, whereas the stretching of reaction zones has an unfavorable effect. In contrast, heat loss contributes negligibly to the difference between the blowout limits in the micro-combustors for different values of δ. An extra pressure loss or initial power input is required to improve the blowout limits. An available size of the in-built bluff body should be carefully selected to maximize its efficiency and to considerably improve the blowout limit; however, this should be realized while ensuring a low cost of pressure loss when designing a micro-combustor. In general, δ = 0.5 is relatively optimal and recommended for the straight combustion channel discussed herein.     

BRJ9604解堵剂在渤海绥中36-1油田的应用

针对渤海绥中 ３６１ 油田注水井堵塞的问题,研制了 Ｂ Ｒ Ｊ９６０４ 解堵剂,给出了其主要技术指标,介绍了该解堵剂在绥中３６１ 油田 Ａ８ 井的现场应用试验情况。试验结果表明, Ｂ Ｒ Ｊ９６０４ 可以有效地解除注水井近井地带的堵塞,使吸水指数明显增加。     

活性自均向稠化酸解堵技术在克拉玛依油田的应用

报道了半活性自均向稠化酸用于高温高压裂缝－孔隙型油藏油井酸化解堵的技术,概括介绍了活性自均向稠化的作用原理,基本组成,性能和解堵工艺,详细介绍了活性自均向稠化酸在新疆克拉玛依油田石西作业区油井酸化解堵中的应用效果。     

电磁加热解除近井地层凝析油堵塞的数学模型

文章针对凝析油堵塞严重影响凝析气井产能的问题，提出了用井下电磁感应加热技术来解除近井地层凝析油堵塞的方法，并建立了相应的数学模型。凝析气的非等温渗流是一个涉及复杂相态变化的过程，采用组分模型存在求解困难及计算所需参数难以获取的问题，文章中渗流模型采用了有限组分模型，既能模拟凝析气相态特征，又避免了复杂的相态计算，而且计算所需参数的获取相对容易。模型中考虑了凝析气的高速非达西渗流。用数值方法对数学模型求解，并研制了模拟软件。     

定位堵塞注射模设计

通过分析定位堵塞成型工艺特点，结合实例，重点介绍了产品有两处侧孔，需要采用侧抽芯来完成侧壁孔成型的模具结构特点，对同类模具设计有一定的参考价值。     

基于人工神经网络的定子绕组堵塞故障诊断新方法

本文提出了基于人工神经网络(Artificial Neural Network简称ANN)的定子绕组堵塞故障诊断新方法，首先分析堵塞故障的特征，计算各种故障时的温度分布，使定子绕组各测点的温升和不同故障之间，建立一一对应关系的数学模型，然后构造神经网络，从而提高故障诊断的准确性。     

油层解堵剂CY—3的性能与应用

提出了使用解堵剂ＣＹ３解除油藏水堵的方法。讨论了油层中水堵（水锁）的形成。简介了解堵剂ＣＹ３的组成，测定了ＣＹ３降低油田污水和淡水表面张力的能力，通过人造和天然岩心模拟实验考察了ＣＹ３解除泥浆和油污造成的堵塞的能力。通过若干井例简介了ＣＹ３在国内许多油田应用的情况。     

反吹处理6000m~3/h制氧机液空流路堵塞

福建三钢 60 0 0m3/h制氧机液空流路被二氧化碳等杂质堵塞 ,采用不停机利用上塔气体进行反吹操作方案解决了故障。文章详细介绍了处理的方案、方案实施过程中的问题及解决方法 ;粗略分析了效应 ,提出了预防措施     

MY—Ⅲ油层处理剂的研制及现场试验

MY-Ⅲ具有破乳、降粘和一定的溶蜡作用,是一种能解除油井近井地带堵塞的复合型油层处理剂。本文介绍了MY-Ⅲ油层处理剂的研制情况和现场试验结果,提出了MY-Ⅲ的现场应用工艺。