正弦波电磁场对瓦斯吸附常数的影响规律

对不同变质程度煤瓦斯吸附常数a、b值的电磁效应进行了实验研究．研究表明，正弦波电磁场作用对吸附常数a值影响不大，可以明显的减小吸附常数b值．吸附常数b值随电磁场频率的增高成负指数幂减小，随电磁场电压的升高成线形减小．外加电磁场作用可以降低煤对瓦斯的吸附能力和吸附量．     

关于温度对煤吸附瓦斯性能影响的研究

采用HCA型吸附常数测定仪,对不同矿区的煤样进行不同温度下的吸附瓦斯等温线测试,通过对实验结果的分析,研究了温度对煤吸附瓦斯性能的影响,认为:由于煤自身结构的特殊性,从而造成极限吸附量随温度的变化呈现出非单调性的特征,而随着温度的增加实验煤样的吸附常数b呈现出良好的减函数特征。因此,在工程实际中,应充分考虑煤类型和煤层温度变化规律来确定煤层的瓦斯含量。     

温度对煤体瓦斯吸附特性影响实验分析

为深入探讨温度对煤体瓦斯吸附特性的影响,在分析煤体瓦斯吸附/解吸机理的基础上,深入调查了近十几年来相关学者开展的29组温度对煤体瓦斯吸附特征影响实验,统计了实验结果数据,从概率论与数理统计的角度对实验结果进行了分析,研究了温度对煤体瓦斯吸附特性的影响规律.拟合了吸附量、Langmuir吸附常数与温度的函数关系式.提出了目前实验研究中存在的不足之处,进而确定了今后需要深入研究的方向.研究成果对于促进瓦斯灾害防治及煤层气开发利用理论及技术的发展具有一定的参考价值及指导意义.     

构造破坏煤的煤化程度及其瓦斯地质意义

淮北宿东矿区和淮南谢二矿的某些煤层采到过强烈的后生构造破坏，煤体的破碎强度与矿井瓦斯及煤的煤化程度的加深存在正相互关系。     

煤吸附瓦斯过程温度变化的试验研究

在实验室对不同瓦斯（ＣＯ２,Ｃ４,Ｎ２等）吸附过程中煤体温度的变化进行了研究,证实煤体吸附瓦斯的过程是放热过程;煤体吸附不同的瓦斯时,放出的热量不同：吸附ＣＯ２时最大,ＣＨ４次之,Ｎ２最小;煤对其吸附能力超强的瓦斯,吸附时放出的热量越大,对于同一种瓦斯,吸附的瓦斯压力越大,即瓦斯附量越大,吸附过程放出的热量越大。     

吸附气体对受载含瓦斯煤渗流特性影响的试验研究

利用自主研发的含瓦斯煤岩三轴压缩试验系统,进行了大量受载瓦斯煤的渗透特性室内试验,对比分析了CO2,CH4和N2的渗透率之间的异同.研究结果表明,在恒定瓦斯压力条件下,煤样渗透率随围压的增大而减小,均服从负指数函数变化规律;在恒定围压条件下,煤样渗透率随瓦斯压力的增加而减小,并且表现出幂函数变化规律;吸附性强弱不同的气体所表现出来的渗透性也不一样,气体吸附性越强,渗透性越弱;在轴向加载情况下,不同气体的渗透率都表现出先减小后增大的现象,并且具有一般的"V"字型变化规律.研究结果对深入认识煤层瓦斯运移规律具有一定的理论价值.     

物理吸附与化学吸附

在催化过程中,物理吸附和化学吸附是同时进行的。实验事实表明,在低复盖率时,可能存在理想气固吸附平衡的情形,热力学平衡常数Ｋａｄ由一组方程定义。     

对煤吸附甲烷的Langmuir方程的讨论

煤吸附甲烷量一般用Langmuir方程来表示.Langmuir方程是用单分子层吸附模型推导出来的;在理论上,煤吸附甲烷不符合单分子层吸附模型.由于煤吸附甲烷得到的吸附等温线都属于第Ⅰ类吸附等温线,所以可以用Langmuir方程来表示煤吸附甲烷量;同时,Langmuir方程使用方便,两个吸附常数a和b的物理意义明确,因而应用广泛。     

Effect of surfactant Tween on induction time of gas hydrate formation

Acceleration of gas hydrate formation is important in preventing coal and gas outbursts and is based on a hydration mechanism. It becomes therefore necessary to investigate the effect of surfactants, acting as accelerants for hydrate formation, on induction time. We experimented with three types of a Tween solution with equal concentrations of 0.001 mol/L (T40, T40/T80 (1:1), T40/T80 (4:1)). By means of visual experimental equipment, developed by us, we measured generalized induction time using a Direct Observation Method. The experimental data were analyzed combined with a mass transfer model and a hydrate crystal nuclei growth model. Our major conclusions are as follows: 1) solubilization of surfactants produces supersaturated gas molecules, which promotes the mass transfer from a bulk phase to hydrates and provides the driving force for the complexation between host molecules (water) and guest molecules in a gas hydrate formation process; 2) when the solution of the surfactant concentration exceeds the critical micelle concentration (CMC), the surfactant in an aqueous solution will transform to micelles. Most of the gas molecules are bound to form clusters with water molecules, which promotes the formation of crystal nuclei of gas hydrates; 3) the surfactant T40 proved to have more notable effects on the promotion of crystal nuclei formation and on shortening the induction time, compared with T40/T80 (1:1) and T40/T80 (4:1).     

乙醇——水气相吸附过程的研究 (一)吸附平衡

本文是在研究以多醣类物质作吸附剂制取无水乙醇的新工艺基础上,采用迎头色谱法测定了吸咐等温线,突验数据通过回归分析,获得符合Freundlich型的吸咐等温方程,计算值与实验结果吻合较好。实验还证明了多醣类物质在实验的温度范围内,选择性地吸附水蒸汽,而不吸附乙醇蒸汽。     

Pore characterization of different types of coal from coal and gas outburst disaster sites using low temperature nitrogen adsorption approach

To characterize the pore features of outburst coal samples and investigate whether outburst coal has some unique features or not, one of the authors, working as the member of the State Coal Mine Safety Committee of China, sampled nine outburst coal samples(coal powder and block) from outburst disaster sites in underground coal mines in China, and then analyzed the pore and surface features of these samples using low temperature nitrogen adsorption tests. Test data show that outburst powder and block coal samples have similar properties in both pore size distribution and surface area. With increasing coal rank, the proportion of micropores increases, which results in a higher surface area. The Jiulishan samples are rich in micropores, and other tested samples contain mainly mesopores, macropores and fewer micropores. Both the unclosed hysteresis loop and force closed desorption phenomena are observed in all tested samples. The former can be attributed to the instability of the meniscus condensation in pores,interconnected pore features of coal and the potential existence of ink-bottle pores, and the latter can be attributed to the non-rigid structure of coal and the gas affinity of coal.     

多重离子平衡的平衡常数的计算和应用

根据多重离子平衡体系中Ｇｉｂｂｓ函数变及其与平衡常数关系的原则，提出多重离子平衡的平衡常数的计算方法．     

液态水对煤吸附甲烷影响的机理分析

为了研究液态水对煤吸附甲烷影响的机理,进行了不同煤级干燥煤样、平衡水煤样和注水煤样等温吸附实验,基于分子间作用力对液态水影响机理进行分析,并用维里方程拟合等温吸附实验结果来验证.结果表明,煤基质的润湿程度是液态水影响煤吸附甲烷的主要因素.干燥煤样中煤与甲烷分子间作用力远大于甲烷分子间作用力,第二维里系数较低,吸附能力强;平衡水煤样中煤与水分子氢键能高于范德华力,气态水分子竞争吸附,第二维里系数偏高,煤基质吸附能力弱;注水煤样中煤与甲烷分子之间长程作用力和甲烷与水分子之间短程作用力之和较小,与甲烷分子间作用力相当,第二维里系数最高,煤基质吸附能力很低.煤级增高,煤基质表面极性及其润湿程度降低,第二维里系数随之降低.     

基于一元非线性回归理论的矿井深部瓦斯含量预测

为了对矿井深部煤层瓦斯含量随埋深的变化形态做出新的研究和探讨,以某矿区煤层瓦斯含量与埋深数据为例,采用基于一元非线性回归理论的数学方法,提出一种适合该矿区煤层甲烷带内瓦斯含量随煤层埋深相关关系较好的双曲线型数学模型;在其有效拟合区间内,通过该数学模型对矿区井田内深部瓦斯含量进行预测．结果表明,该矿区井田内相同煤层埋藏深度下实测瓦斯含量同模型预测瓦斯含量能够较好吻合,说明该模型对本矿区井田内瓦斯含量的预测是可靠的．此外,通过吸附常数a值与模型极限值的比较结果,可进一步验证数学模型的预测精度．     

Robust user equilibrium model based on cumulative prospect theory under distribution-free travel time

The assumption widely used in the user equilibrium model for stochastic network was that the probability distributions of the travel time were known explicitly by travelers. However, this distribution may be unavailable in reality. By relaxing the restrictive assumption, a robust user equilibrium model based on cumulative prospect theory under distribution-free travel time was presented. In the absence of the cumulative distribution function of the travel time, the exact cumulative prospect value(CPV) for each route cannot be obtained. However, the upper and lower bounds on the CPV can be calculated by probability inequalities.Travelers were assumed to choose the routes with the best worst-case CPVs. The proposed model was formulated as a variational inequality problem and solved via a heuristic solution algorithm. A numerical example was also provided to illustrate the application of the proposed model and the efficiency of the solution algorithm.     

天然气吸附床脱附过程的传热实验研究

对天然气吸附床在绝热条件下进行了脱附过程的传热实验,实验测量了吸附床在脱附过程中温度分布与变化,实验结果表明吸附床的温度随放气量的增加不断降低,数值达-35℃左右,而且温度分布极不均匀,相差达到40℃。实验发现吸附床中气体渗透对温度分布与变化有较大影响,较低的温度也严重降低了天然气的释放,从而降低了有效天然气吸附量。本文实验数据为采取强化吸附床的传热与传质技术和控制吸附床的温度提供参考。     

电导法测定解离平衡常数及临界胶束浓度的实验改进

通过使用电导率仪的温度补偿功能和等温滴定电导实验方法使测量水溶液中醋酸的解离平衡常数和十二烷基硫酸钠的的临界胶束浓度实验过程得以简化,具体表现为在电导法测量弱电解质解离平衡常数实验过程中可以不使用恒温水槽、水浴夹套等恒温设备,而在电导法测量表面活性剂临界胶束浓度实验过程中则无需单独配置多个不同浓度的十二烷基硫酸钠溶液,以上实验改进可减轻学生在教学实验过程中的工作量,同时加深学生对电导率仪工作方式、等温滴定电导实验方法的理解.