工作面开采强度对RUSLE坡度坡长因子的影响规律

水土流失加剧是西部煤矿区面临的主要生态环境问题之一,煤炭井工开采导致地表不同程度下沉变形,改变了坡度坡长因子,破坏了原有的地表水文过程,从而改变了矿区的水土流失状况。因此,掌握工作面开采强度对水土流失的影响规律,对科学设计开采强度、防控水土流失具有重要指导意义。坡度坡长因子是经典土壤流失方程中的关键变量,其对水土流失具有重要影响。针对工作面开采强度与修正的通用土壤流失方程(Revised Universal Soil Loss Equation,RUSLE)坡度坡长因子相关性关系问题,结合工作面现场地表下沉移动监测数据、开采沉陷概率积分法以及修正土壤流失方程,推导了坡度坡长因子计算方法,研究了地下开采强度与修正土壤流失方程中坡度坡长因子变化之间的关系,为平衡开采强度与矿区水土流失防治提供了理论依据。研究结果表明:(1)基于概率积分法预测得到的坡度坡长因子剥离了采前自然起伏地形的影响,其结果能够更为直观地表现出开采强度与坡度坡长因子变化的相关性,得到的研究结论普适性更强;(2)坡度坡长因子与工作面采高呈正相关关系(R=0.757 1,显著相关性p=0.048 7),与深厚比呈显著负相关关系(R=-0.952 2,p=0.000 9),且二者相关度均较高;(3)在达到充分采动后,日开采体积、采宽的变化对坡度坡长因子的变化不产生显著影响。     

Effect of post-combustion air distribution on NOx original emission and combustion characteristics of 75 t/h coal slime circulating fluidized bed boiler

Coal slime has been discharged or piled up on the spot as solid waste for a long time, causing a lot of waste of resources and environmental pollution. A 75 t/h circulating fluidized bed (CFB) boiler with post-combustion technology was built for combustion of coal slime. To explore the post-combustion technology and the influences of post-combustion air speed and number of post-combustion air nozzles on combustion and original NO_x emission characteristics of Yankuang Coal Slime, the experiments were carried out on a 75 t/h circulating fluidized bed industrial boiler. The experimental results showed that post-combustion technology makes the NO_x original emission lower and can meet ultra-low emission requirement. Both the post-combustion air speed and the number of post-combustion air nozzles affected the post-combustion air flow. As the post-combustion air speed and the number of post-combustion air nozzles increase, NO_x original emissions decreased and CO emissions increased slightly.     

冲压式气动系统的建模与线性化分析

针对一种冲压式气动系统,建立了冲压式气动系统的数学模型。考虑到系统的非线性特性,设计了一种基于脉宽调制线性化的控制方法,取代了原有的振荡线性化控制,并对其进行仿真分析。结果表明,系统的性能满足系统设计要求。试验结果与仿真结果基本一致,仿真计算可以用于冲压式气动系统性能的优化与分析。     

大柳塔煤矿52煤7m大采高综采工作面支架工作阻力分析

为了提高液压支架选型的合理性,实现7m大采高工作面的安全高效生产,本文通过对大柳塔煤矿7m大采高52303工作面、52304工作面初采、正常回采、末采期间的的矿压进行实测,得出大采高工作面周期来压较明显,来压时煤壁片帮严重、顶板下沉明显,易冒顶,来压期间支架工作阻力沿工作面倾向呈"几"字型分布的矿压规律。并分析了支架的受力特点,通过经验及理论公式对工作阻力进行了分析,并结合覆岩运动规律及形成的结构,给出了支架工作阻力确定公式及合理的工作阻力,即16800kN液压支架处于高位运行状态、18000kN液压支架工作阻力相对不足,目前大柳塔煤矿52煤使用的支架不能满足安全生产的需求,合理的工作阻力应为18550k~21586kN。     

基于PSR模型的煤矿本质安全评价新方法

实现本质安全化是我国煤矿建设的重要工作,为了更加准确、合理地进行煤矿本质安全性评价,在目前本质安全评价研究成果基础上,将PSR(Pressure—压力、State—状态、Response—响应)框架模型应用于煤矿本质安全评价,应用层次分析法建立了煤矿本质安全性评价指标体撤消和评价模型,并对煤矿进行了评价,结果表明:PSR框架模型应用于煤矿本质安全评价是准确合理的,且对煤矿本质安全化建设具有重要促进意义。     

浮选药剂乳化装置与浮选工艺参数自动控制系统在老石旦选煤厂的应用

针对老石旦选煤厂浮选系统存在的问题,采用浮选药剂乳化装置及浮选工艺参数自动控制系统对其进行了改造,并确定了合理的加药方式及多点加药的添加点,从而满足了生产工艺要求,达到了降低药耗,提高精煤产率的目的,取得了良好的经济效益和社会效益。     

基于Workbench多倾角型振动筛的模态分析

以申克SLO2496香蕉型振动筛为研究对象,通过现场测量获得具体的尺寸数据,并结合使用厂家的维修手册对其进行三维模型的建立。将建立好的模型导入有限元分析软件Workbench进行振动模态分析,得到振动筛的各阶固有频率及振型。同时,通过理论分析将整个振动筛系统简化为一个单自由度的振动系统,对其进行理论计算获得系统固有频率,其次对振动筛进行锤击测试试验获取试验模态结果,最后与有限元结果相比较验证其合理性。最终结合各阶固有频率及振型的分析结果,提出合理的设计改进,使激振频率尽量远离共振频率范围,避免振动筛在使用过程中各部件之间产生共振导致其损坏从而降低整个振动筛的使用寿命的问题,同时分析结果可以为进一步的动力学分析提供必要的理论依据。     

管片衬砌配合碎石可压缩层的斜井支护结构型式及其应用

 提出一种适用于TBM工法修建高地应力深部斜井的管片衬砌配合碎石可压缩层的让压支护技术。结合台格庙矿区TBM施工的长距离斜井工程,采用有限差分与离散元的耦合计算方法,从围岩塑性区发展、管片衬砌接触力、管片衬砌弯矩和轴力分析碎石可压缩层的让压效果,从碎石可压缩层的压缩变形路径和颗粒移动特征角度揭示碎石可压缩层的让压机制。研究结果表明：碎石可压缩层的密实度和地层的地应力分布情况影响其让压效应,密实度主要影响接触力的大小,而地应力条件主要影响接触力的形状,从而影响管片衬砌的内力分布形状和大小;碎石可压缩层的让压机制由相互嵌挤作用和错动移位作用两部分组成。不同地应力组合和不同的密实度时,嵌挤作用和错动移位作用各自发挥的程度不同,从而引起碎石的压缩变形路径差异,最终导致不同的让压效果。研究结果对未来TBM工法修建深部斜井的支护结构型式设计具有一定参考价值。     

Investigation on and industrial application of degrading of methanol feed in methanol to propylene process

At present, methanol to propylene (MTP) technology developed by Lurgi Company is adopted for commercial plants and refined methanol with the purity ≥ 99.85 wt% is required as the feed of MTP unit in Lurgi's technology. Therefore, high energy cost for refined methanol production is one of the bottlenecks to improve the economy of MTP technology. Reducing the grade of feed refined methanol may be an effective method to save energy and reduce operation costs in MTP process. In this work, experiments and process simulation were carried out to investigate the influence and feasibility of degrading the methanol feed. Experiments were conducted to investigate the influence of crude methanol feed on conversion and selectivity of MTP reaction as well as the performance of ZSM-5 catalyst. The experimental results showed that degrading the methanol feed had no obvious influence on the conversion and selectivity of MTP reactions and the catalyst deactivation was caused by the carbon accumulation and metals deposition on the active sites. The process simulation results showed that the influence on the conversion and selectivity as well as the stream load of MTP process was negligible if 98mol% methanol was used as feed. Finally, industrial experiments were conducted by adjusting the operation parameters to degrade of feed methanol of the commercial 500 kt·a^-1 MTP unit of Ningmei Group in China. The results of industrial application illustrated that annually 180 kt fuel coal and 150 kt desalted water as well as1770 MW·h^-1 electricity would be saved when the water content increased from 0.01% to 0.4%. This work has identified the feasibility to improve MTP technology by degrading the methanol feed.     

LabVIEW环境下定容燃烧弹数据采集系统研究

为了精准控制定容燃烧弹的点火和数据采集,本文参考汽车点火系统,利用固态继电器等电子元件,设计了定容燃烧弹的点火控制电路,并利用PCI-1712L数据采集卡等硬件设备,设计了定容燃烧弹数据采集控制虚拟仪器系统,同时采用LabVIEW软件编写了数据采集控制系统程序。经过实验证明,该控制系统能控制定容燃烧弹的点火,调节点火电能量,实现模拟燃烧过程的数据采集、信号波形显示、数据储存等功能。该研究实验过程简便,数据更精准,为内燃机的模拟燃烧实验奠定了理论基础。