Combustion enhancement and inhibition of hydrogen-doped methane flame by HFC-227ea

Hydrogen enriched with compressed natural gas is an efficient and environment-friendly gaseous fuel. However, the safety issues of mixture and the method to control or weaken their combustion are highly concerned. To explore the inhibition effect of halogenated fire suppressants on the mixture, the effect of HFC-227ea on the laminar premixed methane/air flames, with different fractions of H₂, have been studied. Burning velocities have been measured with constant-volume combustion chamber and kinetically modelled a recently assembled kinetic mechanism. The fractions of H₂ influence the enhancement and inhibition effect of HFC-227ea, and it is less effective with the lean mixture. In stoichiometric condition, HFC-227ea showed good inhibition effect on the mixture flames. The HFC-227ea increased the burning velocities of CH₄-0% H₂-air and CH₄-10% H₂-air flames at leanest condition, whereas the increased burning velocity arising from HFC-227ea not occurred as the addition of H₂ above 20%. Experimental results coincided well with numerical results, however the agreement was poor for the leanest flames at low agent loading. Lastly, kinetic mechanism analysis was used to interpret the combustion enhancement and inhibition effect of hydrogen-doped methane flame by HFC-227ea.     

牵引逆变器IGBT风冷散热试验及仿真平台搭建

IGBT散热性能是影响高速动车组在行驶过程中安全性、可靠性及动力性的重要因素。本文以某出口铰接车牵引变流器箱为试验研究载体,研制了专用风冷散热试验台;同时运用仿真软件Flotherm进行了仿真计算,通过实物试验与仿真计算的对比研究,验证了仿真计算的可行性。     

炼油中间油品罐区罐顶气治理

介绍了某石化厂炼油中间油品罐区10台储罐的罐顶挥发性有机物治理方案,改造方案是利用炼油厂现有瓦斯管网系统将其回收利用。包括罐顶油气收集管线和增压风机,并完善储罐氮封和安全附件。该方案需根据储罐的基本情况制定合理的压力控制方案和应急安全措施。该治理方案投资小,运行费用低,不仅取消了废气排放口,而且有较高的经济效益,可作为优先选用的炼油罐顶气治理方案。     

煤矿井下风水管路压力在线监测系统的研究与应用

为提高井下管路供风、供水的安全性、可靠性，以工业环网作为网络通信平台，通过分站采集数据上传至地面，实现对煤矿井下供风、供水管道的远程实时监控及远程控制，及时发现管网故障，提高维护效率、降低损失，保障供风、供水质量，达到科学预警、降低成本、提高效率的目的。     

油藏中后期减氧空气驱提高采收率机理研究

尕斯库勒油田E¹₃油藏已经进入高含水时期，储采失衡加剧，综合含水率达到了80%以上，原油产量下降，经济效益变差。为了提高油藏原油采出程度、改善油藏开发效果，调研了国内外减氧空气驱的机理研究以及现场试验的资料，建立了以油藏真实孔渗饱数据为基础的一维条形地层机理模型，并选取该油藏Y12-27井组进行了减氧空气驱可行性验证。研究表明:纵向顶部减氧空气驱驱油效果优于水驱和氮气驱；驱替压力对原油采出程度影响不大；注水转注气可以提高原油采出程度；对于减氧空气驱，由于低温氧化反应的作用，氧气浓度对原油采出程度有一定影响，但比较微弱，其中，氧气浓度为10%时，驱替结束采出程度最高；尕斯库勒油田E¹₃油藏属于注水开发“双高”油藏，适用于减氧空气驱；对于该油藏Y12-27井组，顶部减氧空气驱驱油效果好于水驱和氮气驱，建议氧气浓度超过10%时采取关井等措施。     

生物氧化预处理中进气量实时预测数学模型研究

精准预测生物氧化预处理中的进气量对提高黄金提取率和节能降耗具有重要意义。以气体管流连续性方程和运动方程为控制方程，采用Preissmann隐格式法作为差分方法。同时，根据集合卡尔曼滤波(Ensemble Kalman filter，EnKF)算法原理，构造进气量、压强的状态空间模型。结果表明，基于气体管流控制方程建立的进气量模型预测结果与实际进气量观测值具有较好的一致性；与传统静态预测方法相比，EnKF同化方法引入实时观测值和模型参数的更新，有效提高了进气量的预测精度，其平均绝对误差、平均相对误差和均方根误差有明显的降低。可见，基于气体管流控制方程建立的预测模型结合EnKF同化方法是提高生物氧化槽进气量预测精度的有效手段。     

井下通风、排水及压缩空气设备选型设计

依据井下通风方式及瓦斯含量对井下通风设备进行了选型设计,给出了进行反风时的通风机工作特性以及通风机的电控形式;对井下排水设备和压缩空气设备进行了选型设计。井下工程实践表明,所选用的设备可满足矿井的正常生产需要。     

Indoor levels of volatile organic compounds at Florentine museum environments in Italy

Indoor Air Quality monitoring in cultural institutions is of particular concern to protect these places and the cultural heritage content. An indoor monitoring campaign was performed in three museums in Florence (Italy) to determine the occurrence and levels of volatile organic compounds (VOCs). VOCs of interest included BTEX (benzene, toluene, ethylbenzene, xylenes), terpenes, aldehydes, organic acids, and cyclic volatile methyl siloxanes (cVMS). The most abundant VOCs in all samples analyzed were BTEX, which were strictly related to the traffic source, followed by siloxanes and terpenes. Among BTEX, toluene was always the most abundant followed by xylenes, ethylbenzene, and benzene. cVMS in exhibition rooms with the presence of visitors showed higher values compared to samples collected when the museums were closed. Terpenes showed not only the influence of vegetation-biogenic sources surrounding a museum but could also be related to the wood used for the construction of showcases and furniture and the use of cleaning products. Data obtained also showed the presence of organic acids and aldehydes whose source can be traced back to exhibits themselves and wood-based furniture. Assessing the levels of organic acids in museums is important because, over time, it can cause deterioration of the artifacts.     

链条炉运行参数对燃烧及NOx排放的影响

通过数值模拟的方法研究了过量空气系数、配风方式、空气预热温度和炉排转速等运行参数对床层燃烧和氮氧化物排放特性的影响。研究结果表明:过量空气系数增大可加快床层整体反应速率,缩短反应区长度,增大床层表面氮氧化物质量浓度;合理推迟配风有利于扩展反应区整体长度,充分利用整个炉排;适当降低炉排转速有利于提高煤着火及前期反应速率,稍缩短总体反应区间;提高空气预热温度有利于煤着火和前期反应速率的提高,且有利于煤的燃尽。