综采面过断层技术分析

以综采面过断层技术为对象开展分析,结合具体工程实际,在分析作业面所面临过断层问题的基础上,对过断层方案从超前注浆、过断层期间支护和过断层期间安全措施等多个方面进行全面、翔实的设计,希望能够为其他矿井相似工程的开展提供借鉴和帮助。     

高性能过冷水连续制冰系统

过冷水连续制冰是最近发展起来的一种新的制冰技术，与传统的静态制冰相比，具有较高的制冰率和能量效率，制出的泥状冰分散性好，可以直接随水在管道中输送，在前文研究的基础上，建立了具有较高性能的过冷水连续制冰系统，过冷却器换热段长度3m，过冷却器进口水温为0．5℃，出口水温达到－3．3℃，系统性能可望进一步提高，达到实际开发利用的水平。     

综采作业面过断层方法探讨

以综采作业面过断层方法为对象开展探究,结合具体工程实际,在分析作业面过断层存在问题的基础上,从回采工艺和回采作业方案2个方面开展技术优化探究,并对优化后方案的应用效果做出分析。结果表明,所设计技术方案能够有效提升作业面过断层效率,对提高矿井生产综合效益和安全性具有积极意义。     

浅谈600MW等级超临界工程屏过、末过、高再管屏乱排问题

介绍了600MW等级超临界锅炉屏过、末过、高再管屏乱排问题,原因分析及处理方法.     

井下综采作业面过断层技术分析

以井下综采作业面过断层技术为对象开展探究,结合具体工程实际,在分析常规松动爆破过断层工艺不足的基础上,对松动爆破过断层工艺的不足开展综合分析,并对其应用效果做出总结,希望能够为其他矿井相似工程的开展提供借鉴和参考。     

碳纤维复合芯导线过滑车散股现象

针对碳纤维复合芯导线在过滑车后可能出现的散股现象进行了研究。首先对碳纤维复合芯导线过不同底径的滑车进行了有限元分析,得出碳纤维复合芯导线过滑车时随着滑车底径的增大散股现象变小,过20 D滑车时相邻铝线最大散股间距为3.08 mm,过40 D滑车时相邻股线最大距离为0.6 mm。其次通过实验分析了碳纤维复合芯导线过滑车时导线表面的变化以及过不同底径滑车后导线表面的散股程度,选取过滑车后的其中一根试件进行张力为1%RTS、10%RTS、20%RTS、30%RTS条件下导线外观的观察,得出随着张力增大导线散股现象有明显改善。当导线张力在20%RTS以上时导线表面散股现象很小。通过有限元分析以及实验研究得出碳纤维复合芯导线过滑车时散股现象的严重程度与滑车底径成反比,但在实际工程中含张力的情况下散股现象较小。     

过冷水动态制冰技术的应用前景

阐述了国内外过冷水动态制冰技术的发展情况,并介绍了几种主要的制冰技术。通过分析不同制冰技术的优缺点,论证了过冷水动态制冰技术具有较高的制冰率和能量效率。最后,通过分析过冷水动态制冰的原理,展示了过冷水动态制冰技术的应用前景。     

末过爆管分析及处理

介绍了末过设计参数,以及爆管的外表特征,对原始爆口进行光谱、硬度、力学等实验,最后通过金相组织分析得出结论为长期超温爆管。根据现场情况对末过入口管屏进行更换,并提出建议和预案。     

浅析190系列柴油机温度过高的原因

柴油机温度过高主要表现为水温、油温过高两大类。分别分析了造成这两大类温度过高的原因。     

怎样诊断柴油机供油时间过迟

当柴油机工作无力,排气管冒黑烟,启动困难,并伴有敲缸声时,往往是由于供油时间不正常(过早或过迟)引起的。如何确定它是由供油时间过迟引起的故障呢? 一般来说,供油时间过迟的柴油机具有以下几个明显的特征: (1)排气管在小负荷及无负荷时也冒黑烟。     

活塞环厂家必须重视试验研究工作

随着我国交通运输业和汽车工业的快速发展 ,使活塞环行业出现蓬勃生机。原有的活塞环厂在发展 ,新的小厂如雨后春笋般建立。活塞环市场既繁荣而又混乱。由于人们手头缺乏有说服力的科学证据 ,那些权威院所和专业厂家又不出来指点迷津 ,因此在市场的广告性宣传和商业炒作的波涛中被搞得昏头转向 ,无所适从。在此 ,不妨先举两个令人迷惑而殷切盼望答案的事例 :前段时期 ,市场上出现了 61 0 0 Q“封口环”的“专利发明”,整组活塞环的价格上扬了 5 0 %。这么赚钱的东西当然有巨大的诱惑力。大厂小厂跟着一哄而上 ,“专利”拥有者要“打假”,“…     

有无横向联结系对小湾中孔弧门的影响

对于小湾中孔工作弧门这一高水头的弧形闸门,其主要构件的刚度较大,结构的节点效应和空间效应很强,现行闸门设计规范的平面体系算法过于简单,计算成果的误差较大,已不能满足大型深孔闸门结构计算要求。本文采用三维有限元法对该闸门进行结构分析和应力计算,并在此基础上分析有、无横向联结系对该弧门整体的变形和应力的影响,结果证明该弧门采用无横向连接系的方案更加优越,对闸门设计有较大的参考价值。     

Much enhanced electrocatalysis of Pt/PtO2 and low platinum loading Pt/PtO2-Fe3O4 dumbbell nanoparticles

Pt/PtO₂ nanoparticles (NPs) have been prepared by a simple synthetic strategy, easily able to control nanoparticles (NPs) size, consisting in the thermolysis of a suitable precursor in organic solvent under a low oxygen enriched atmosphere. An excellent combination of a low tafel slope of 31 mV/dec with a negligible overpotential was measured for our Pt/PtO₂ NPs, due to PtO₂ resulting in electron rich Pt island, showing activity higher than that of common Pt. Additionally, the paper proves that it is possible to improve platinum/platinum oxide activity through control of NPs size and reduce platinum loading through its junction and interaction with a further metal oxide. Very high hydrogen production rate of 3.35 mL cm^?2 h^?1 at ?0.024 V, obtained by means of an on-line mass spectrometry analysis, to corroborate the results with a realistic hydrogen production estimation, was measured for Pt/PtO₂ electrode. Moreover, Pt/PtO₂ was stable in corrosive acidic solution during electrolysis under high current density.     

生物质与炉渣混燃循环流化床锅炉设计构想

目前生物质工业锅炉多采用层燃方式,生物质燃料灰熔点较低,灰成分碱金属含量高,结渣、受热面积灰、腐蚀等情况比较严重,制约层燃生物质锅炉的发展。另外在工业锅炉占很大份额的燃煤层燃炉炉渣含碳量普遍高于20%,造成能源浪费。本文根据生物质燃料以及层燃炉渣的特点,提出燃用生物质与层燃炉渣混合燃料循环流化床锅炉的设计构想。通过合理的燃料配比提高生物质燃料灰熔点,稳定流化床循环物料,采取一定措施减少碱金属的升华和尾部受热面积灰、腐蚀。并对其在小型工业锅炉应用的"节能减排"效果进行了预测。     

Energy and the state of nations

The mathematical conditions for the existence of macroeconomic production functions that are state functions of the economic system are pointed out. The output elasticities and the elasticities of substitution of energy-dependent Cobb-Douglas, CES and LinEx production functions are calculated. The output elasticities, which measure the productive powers of production factors and whose numerical values have been obtained for Germany, Japan, and the USA, are for energy much larger and for labor much smaller than the cost shares of these factors. Energy and its conversion into physical work accounts for most of the growth that mainstream economics attributes to “technological progress” and related concepts. It decisively determines the economic state of nations. Consequences for automation and globalization and perspectives on growth are discussed.     

Coevolution of policy,market and technical price risks in the EU ETS

Within the EU, there have been calls for governments to provide greater certainty over carbon prices, even though it is evident that their price risk is not entirely due to policy uncertainty. We develop a stochastic simulation model of price formation in the EU ETS to analyse the coevolution of policy, market and technology risks under different initiatives. The current situation of a weak (20%) overall abatement target motivates various technology-support interventions, elevating policy uncertainty as the major source of carbon price risk. In contrast, taking a firm decision to move to a more stringent 30% cap would leave the EU–ETS price formation driven much more by market forces than by policy risks. This leads to considerations of how much risk mitigation by governments would be appropriate, and how much should be taken as business risk by the market participants.     

并网双馈风力发电机矢量控制的改进及实现

分析了传统的双馈风力发电控制策略,并在网侧变换器和转子侧变换器中分别使用了电网电压定向和转子侧定子磁链定向的矢量控制.传统的控制策略比较复杂,对其提出了改进方案,改进后的控制方法大大简便.利用PSCAD/EMTDC平台进行仿真表明,改进后的控制方案是正确的.     

A study of the effect of ultrasonic vibrations on phase-change heat transfer

The present paper investigates the effect of ultrasonic vibrations on the melting process of a phase-change material (PCM). Furthermore, the present study considers constant heat-flux boundary conditions, whereas much of the previous research had adopted constant wall-temperature conditions. The experimental results revealed that ultrasonic vibrations accompanied the effects like agitation, acoustic streaming, cavitation, and oscillating fluid motion, accelerating the melting process as much as 2.5 times, compared to the rate of natural melting (i.e., the case without ultrasonic vibration). In addition, temperature and Nusselt numbers over time provided conclusive evidence of the important role of the ultrasonic vibrations on the melting phenomena of the PCM.     

柴油机喷雾夹角对缸内三维流场的影响

运用CFD软件对直喷柴油机燃烧室中的喷雾及燃烧过程进行数值计算,考察了不同喷雾夹角下缸内三维流场及NOx排放的差异,并将计算结果进行了对比分析。结果表明喷雾夹角的增加使凹坑内的空气利用率变差,并使得燃烧高温区域更加接近气缸壁面以及缸盖平面;喷雾夹角的减小使燃烧过程中生成的NOx排放增加并增加了喷油器的热负荷。     

摩托车排放测试的WMTC测试循环

本文介绍了摩托车排放的WMTC（World-wide Motorcycle Test Cycle）测试循环，研究了WMTC测试循环的行驶特征及其与欧3排放测试循环的差异，并初步探讨了两种测试循环下摩托车排放因子的相关性。研究结果表明，较之欧3测试循环，WMTC怠速比例低，稳态工况少，瞬态工况比例高，对摩托车的排放控制技术提出了更为苛刻的要求。WMTC测试循环下和欧3测试循环下摩托车排放因子的相关性分散度较大，且规律性并不明显，表明两种排放因子的相关性有可能只存在于统计意义上。