不同围压下茅口灰岩渐进性破坏的试验研究

利用MTS815电液伺服控制刚性试验机进行不同围压下茅口灰岩三轴压缩试验,通过计算绘得相应裂隙体积应变图,分析得出裂纹起始应力、裂纹破坏应力。结果表明:随着围压的增大,应力门槛值均呈非线性增长态势,当围压超过17 MPa时,裂纹起始应力、裂纹破坏应力分别增加48.5%和20.1%,茅口灰岩延性开始增强;裂纹破坏应力为峰值强度的64%~75%,三轴压缩下茅口灰岩裂隙不稳定发展阶段较长;环向应变值随围压增大而增大,当轴力超过裂纹破坏应力进入裂隙不稳定发展阶段,环向应变增大2.7~3.2倍,用环向-轴向应力应变曲线图能较好的反映岩石应力门槛值。     

高密度电法在灰岩地区勘察中的应用

灰岩地区较为突出的特点就是溶蚀现象较为普遍,会产生较多的溶蚀带、溶洞等不良地质现象,会严重地影响到基础工程质量与施工进度。本文介绍了高密度电法结合其他物探手段对灰岩地区溶洞进行的探测,并根据地震波场特征、面波波速、密实度和电阻率特征,对溶洞进行分类判别。结果证明了高密度电法应用在灰岩地区具有较好的实际效果和应用前景。     

饱水对岩溶灰岩力学性质与纵波波速的影响

为研究饱水对岩溶灰岩力学性质和纵波波速的影响,进行自然和饱水状态下岩样的力学性能和弹性波测试。试验结果表明:饱水对岩溶灰岩的单轴抗拉强度、抗拉强度和弹性模量有明显的软化作用,饱水状态试样的峰值应变和泊松比整体上大于自然状态的对应值;岩溶灰岩试样在饱水条件下的纵波波速均明显高于自然状态下的纵波波速,试样的单轴抗压强度和抗拉强度与纵波波速具有较高的线性相关性。基于目前的研究现状,阐述了研究成果在隧道与周边高压充填隐伏溶腔间防突岩层稳定性评价及最小防突厚度确定中的应用。     

火力发电厂烟气脱硫控制系统介绍

分析了湿法和干法烟气脱硫技术的特点,针对目前国内火力发电厂常用的石灰石洗涤法烟气脱硫系统、海水洗涤法烟气脱硫系统和回流式循环流化床法烟气脱硫系统,介绍了它们的工艺及其控制系统的配置、应用功能,并对控制系统设计与应用中的若干技术问题提出了自己的见解.     

WFGD工艺典型脱硫添加剂应用探讨

鉴于石灰石湿法烟气脱硫(WFGD)技术在脱硫市场的主导地位,对镁、DBA、蚁酸等3种典型脱硫添加剂的作用机理、工业应用等方面作了介绍。用理论和实践证明脱硫添加剂确实能够提高SO2的吸收率和石灰石等吸收剂的利用率,并且具有降低结垢和堵塞风险、节约安装及运行成本的功效。     

Analysis of roof and pillar failure associated with weak floor at a limestone mine

A limestone mine in Ohio has had instability problems that have led to massive roof falls extending to the surface. This study focuses on the role that weak, moisture-sensitive floor has in the instability issues.Previous NIOSH research related to this subject did not include analysis for weak floor or weak bands and recommended that when such issues arise they should be investigated further using a more advanced analysis. Therefore, to further investigate the observed instability occurring on a large scale at the Ohio mine, FLAC3 D numerical models were employed to demonstrate the effect that a weak floor has on roof and pillar stability. This case study will provide important information to limestone mine operators regarding the impact of weak floor causing the potential for roof collapse, pillar failure, and subsequent subsidence of the ground surface.     

Water abundance of mine floor limestone by simulation experiment

The water abundance of mine floor limestone needs to be solved urgently as the average depth of coal mining in China has increased gradually. A method is presented to discuss water abundance with the numerical and physical layered geoelectrical model being established in the half-space, full-space and full-space with tunnel, respectively. The parameters of water abundance are changed in this study, which includes water quantity, water content and volume of abnormity of water-containing abnormity. Results indicate that the different work fields have different macroscopic influences on the apparent resistivity,and the water abundance parameters of water-containing abnormity have quantitative relationship with the apparent resistivity mean in abnormal regions(three-dimensional space region). The quantitative relationships are shown as following: firstly, the amount of water injection has negative linear correlation with the apparent resistivity mean; secondly, when abnormity is unsaturated, there is a negative power function relationship between water content and apparent resistivity mean; thirdly, the volume of abnormity and apparent resistivity mean behave as a decreasing power function law.     

循环流化床锅炉性能试验规程的编制及其特点

介绍了由西安热工研究院有限公司负责起草的电力行业标准《循环流化床锅炉性能试验规程》(DL/T 964 2005)的编制原则和技术特点,并对编制中有关问题的处理作了说明,可供本规程使用者参考。     

石灰石颗粒煅烧特性的模拟与分析

在不同的煅烧温度、颗粒粒径和二氧化碳浓度下对石灰石颗粒进行热重分析。同时,以未反应收缩核为基础,建立石灰石颗粒同时煅烧、烧结模型。分析化学反应、传热传质对颗粒煅烧的影响。结果表明:在煅烧后的 CaCO3-CaO 多孔介质中,化学反应和 CO2的扩散对煅烧起着主导作用。     

水蒸气对石灰石/白云石循环吸收CO_2能力影响

利用自制能实现等温下热重测量的实验系统,研究了水蒸气对不同粒径范围(75~97μm,150~250μm,355~450μm)石灰石与白云石在循环煅烧/碳酸化过程中对CO2吸收能力的影响。结果表明,当不考虑水蒸气时,白云石对CO2的吸收能力要高于石灰石;而考虑水蒸气时,两者对CO2的吸收能力则相差不多。碳酸化阶段水蒸气的存在提高了钙基吸收剂对CO2的吸收能力,尤其对石灰石作用更加明显。如在20%水蒸气下,石灰石循环第8次对CO2的吸收能力为0.24 g/g,而无水蒸气时仅为0.18 g/g。实验结果表明:比较石灰石与白云石对CO2的循环吸收能力时,水蒸气是重要的影响因素。