Rapid regional outburst elimination technology in soft coal seam with soft roof and soft floor

In order to solve the problems in outburst elimination of coal seams with outburst potential, methods of field testing, theoretical analysis and numerical simulation are employed in this study. It is found that the horizontal stress concentration surrounding coal unloading boreholes is the primary cause of the coal and gas blowouts in the process of the coal unloading and permeability improvement with high-pressure water jet. The results indicate that low borehole density and inefficient drainage are the main reasons for the occurrence of high outburst indices in the effeteness validation of regional measures to control outbursts. Based on numerical modeling results and onsite parameter testing, reasonable parameters such as borehole density are determined, and hydraulic fracturing is applied to improve coal seam permeability and relieve stress levels so as to eliminate regional outburst potential. The effect is significant in the field application, coal and gas blowout during the coal unloading period with high-pressure water jet is reduced dramatically, and the roadway development rate is increased by 48%. It is demonstrated that the gas drainage combined with the hydraulic fracturing, coal unloading with high-pressure water jet is a practical and effective technique for rapid elimination of coal and gas outburst potential in roadway development.     

Experimental study on leak detection and location for gas pipeline based on acoustic method

The leak of gas pipelines can be detected and located by the acoustic method. The technologies of recognizing and extracting wave characteristics are summarized in details in this paper, which is to distinguish leaking and disturbing signals from time and frequency domain. A high-pressure and long distance leak test loop is designed and established by similarity analysis with field transmission pipelines. The acoustic signals collected by sensors are de-noised by wavelet transform to eliminate the background noises, and time-frequency analysis is used to analyze the characteristics of frequency domain. The conclusion can be drawn that most acoustic signals are concentrated on the ranges of 0-100 Hz. The acoustic signal recognition and extraction methods are verified and compared with others and it proves that the disturbing signals can be efficiently removed by the analysis of time and frequency domain, while the new characteristics of the accumulative value difference, mean value difference and peak value difference of signals in adjacent intervals can detect the leak effectively and decrease the false alarm rate significantly. The formula for leak location is modified with consideration of the influences of temperature and pressure. The positioning accuracy can be significantly improved with relative error between 0.01% and 1.37%.     

三维地理应急系统在含硫气田开发过程中的建设与应用

针对四川复杂地形含硫气田开发过程中可能出现的火灾、爆炸、原料气泄漏等突发事故,难以及时判断事故的发展趋势并确定有效的应对措施,加之对事发点周边的社会和地理环境不熟悉,极易造成群死群伤事故。研究了适用于安全监管与应急防控一体化的管理系统及“平战结合”的运行模式,开发了石油化工领域专用的空间GIS平台,以空间关系做为数据关联分析的底层逻辑,形成贯穿气田设计、建设、运营全生命周期的数据完整性管理体系。并重点针对含硫天然气事故灾害类型和应急支撑数据采集内容进行研究,形成应急管理与快速响应整套技术方法及示范工程,显著缩短了风险辨识和预警时间,提高了应急响应速度和应急决策能力。     

土壤中有机污染物的气相色谱-四极杆飞行时间质谱非靶标筛查

本文基于气相色谱-四极杆飞行时间质谱(GC-QTOF/MS)对宜昌某化学工业园区内的土壤进行潜在有机污染物的非靶标筛查.根据已有高分辨数据库和保留时间信息,采用精确质量数提取筛查流程识别出样品中96种污染物,主要以多环芳烃及其代谢产物、氯苯类和农药为主.进一步通过未知物分析软件解卷积功能和质谱NIST数据库的匹配,发现了如二氯苯胺、9-芴酮、3-甲基二苯并噻吩等更多的污染物.该方法能够快速筛查和识别出样品中潜在有机污染物,为当地污染物的风险管控提供借鉴意义.     

GGH换热元件结垢堵塞原因分析及防治措施

京隆发电公司脱硫系统运行过程中经常发生GGH换热元件结垢和堵塞现象,分析了GGH结垢和堵塞的原因,主要包括除雾器除雾效率差;脱硫系统水平衡设计不合理;除雾器冲洗水系统故障、设计不当或冲洗不足;吸收塔补充石灰石浆液量过大;GGH换热元件波形板或GGH换热面高度设计不合理;吹灰系统设计不合理;氧化风量不足;吸收塔液位长时间保持在高液位、消泡剂添加不足;燃煤硫分的变化及吸收剂品质不好等。提出了防治措施,较好地解决了GGH换热元件结垢和堵塞的问题。     

顶空-毛细管气相色谱法同步测定水中吡啶丙酮乙腈

建立了顶空-毛细管气相色谱测定水中吡啶丙酮乙腈的方法,不用有机溶剂萃取和浓缩,减少了损失和对环境的污染,具有灵敏度高、检出限低、定量准确、操作简便等特点。当取样量为5ml时,检出限可达到0.006~0.03mg/L级,相对标准偏差为1.0%~2.3%,加标回收率在78.0%~100.2%之间,完全适合水中吡啶丙酮乙腈的测定。     

我国农村推广秸秆类生物质气化集中供气技术探讨

从提高秸秆类生物质利用效率与利用价值、提高农民生活质量与生活品位、减少污染、充分利用可再生能源资源和延缓不可再生能源资源的持续利用等,阐明推广应用秸秆类生物质气化集中供气技术的重要意义;介绍气化基本原理与工艺流程,秸秆类生物质粉碎后通过干燥、裂解反应、氧化反应和还原反应,即可完成气化全过程;气化工程由燃气发生炉机组、储气柜、输气管网和用户燃气设备4部分组成;秸秆类生物质燃气与城市管道煤气具有共同的特点。     

柴油车尾气残余物有机污染特征及其环境危害

利用大型烃分析仪(GHM)对小型柴油车尾气排气管内的黑色残余物进行了定量和定性分析,讨论了残余物质中所含各种类型有机污染物的数量和组成特征。研究结果表明,柴油机在燃烧过程中存在着不完全燃烧现象,尾气黑色残余物中含有129.17mg/g的有机污染物,它们大多为可造成严重环境污染的高熔点、强毒性的重质极性有机污染物。     

西气东输工程的环境协同效应研究

协同效应研究是气候变化政策研究的新领域,也是非常重要的领域.西气东输工程的主要目的是为我国中东部地区输送丰富的天然气资源,但其实施同时也有助于减少东部地区大气污染物排放,改善大气质量.利用较成熟的中国区域环境与经济综合评价模型(AIM-LOCAL/China模型),从用气项目的SO₂和CO₂排放的常规情景(BAU)和利用天然气后的情景(NGS)两方面进行了量化比较,分析西气东输工程的环境协同效应.研究发现:在用气项目的范围内,NGS情景下的SO₂排放相比BAU情景明显减少,同时CO₂等温室气体排放也大幅减少.2003-2020年,累计可以减排约312×104 t SO₂和3 475×104 t CO₂,分别比BAU情景减排40.5%和17.9%.从4个用气部门来看,不论是SO₂还是CO₂,电力部门用气项目的减排量都占突出位置.      

Atmospheric measurements of the halogenated hydrocarbons involved in global change phenomena

Chlorofluorocarbons and their replacement compounds are anthropogenic compounds of great environmental concern. For this reason monitoring their atmospheric mixing ratios on a worldwide scale is recommended. An analytical methodology for the simultaneous determination of selected chlorofluorocarbons and their replacement compounds has recently been developed. This methodology was applied in the analysis of actual air samples collected in remote and semi-remote areas located in the Northern and Southern Hemispheres. The concentration levels measured in the air samples collected in the two hemispheres are reported.