Study on Methane Flow Regularity and Secondary Stress and Deformation of Coal Bady around Penetration Boreholes in Coal Seam

A new mathematical model for the coefficient of variable permeability affected by coal body, secondary stress & pressure in coalseam & a constitutive equation for gas migration are improved on the basis of the secondary stress & deformation of coal body around boreholes in coalseam. Using this model and equation,the gas flow field belongs to the 20102 experimental zone in BaiJiao coal Mine is computed & this verifies that the model & constitutive equation are both agreeable to practical results. Simultaneously, a comparison between the variable and constant permeabilities is carried out.     

The Quantitative Analysis of the Fatalness of the Methane Explosion in Coal Mines

If the quantitative index of the methane explosion in coal mines before exploding can be calculated, the measure will be take to prevent the methane explosion. The methods using in the analysis of the fatalness of the methane explosion are almost qualitative analysis. In this paper the quantitative analysis of the fatalness of the methane explosion in coal mines is achieved on the basis of the research of the essence event probability with the method of fault tree analysis using the micro-computer. The practical example of the quantitative analysis of the fatalness of the methane explosion in coal mines is given.     

Economic Benefit Analysis on the Exploitation and Utilization Coal bed Methane

The gas accident in Coal Mine is an important safe hidden trouble.The notion on the prevention and cure of gas accident should be changed.Coal gas is a kind of deleterious gas,but it is a clean energy resource.The actualities of coal bed methane resources and its use in our country are reviewed.The foreground for the use of coal bed methane is analyszed.The economic benefit of coal bed methane utilization is evaluated by the Net Present Value(NPV) and the Internal Rate of Return(IRR)method.The results are shown that the utilization of the coal bed methane can decrease the gas accident,save energy source,reduce the environmental pollution,and have remarkable economic benefit.     

生活垃圾卫生填埋甲烷排放及减排研究进展

卫生填埋是生活垃圾最主要的处理方式,生活垃圾卫生填埋场产生甲烷(CH₄)等温室气体,加快全球气候变暖进程,引起各国政府的高度重视。笔者探讨了影响生活垃圾卫生填埋场CH₄产生的因素,对CH₄减排技术进行了总结。目前,生活垃圾卫生填埋场CH₄减排技术主要包括填埋层原位减排、资源化利用和末端控制技术等。为了控制和减少CH₄排放量,中国需要增加技术和设施投入,加强生活垃圾卫生填埋场气体排放的管理,开发有效的CH₄抑制技术,建立适合中国国情的CH₄等温室气体减排技术体系。     

茶皂素对奶牛瘤胃甲烷菌及甲烷排放的影响

(目的)本试验旨在通过体外发酵模型与体内试验相结合研究不同添加剂量的茶皂素(tea saponin,TS)对奶牛瘤胃甲烷菌及甲烷排放的影响。(方法)体外发酵模型以0.5g常规全混合饲粮(TMR)为底物,添加TS的浓度梯度为0(对照)、5、10和15 g/L。体内试验采用4×4拉丁方设计,选取4头装有永久性瘤胃瘘管的健康荷斯坦奶牛,饲喂常规TMR饲粮,添加TS的浓度梯度为0(对照)、15、30和45 g/d.头,自由饮水,试验共进行4期,其中包括预饲期7d,试验期14d。通过采集瘤胃液并提取其中基因组DNA,进而计算甲烷菌及其他菌种的基因拷贝数,以此确定瘤胃中甲烷菌的总数与结构。(结果)结果表明,1)添加TS对体外发酵模型中甲烷菌总数没有显著影响(P>0.05),但能够明显改变甲烷菌结构,即甲酸甲烷杆菌(M.formicium)与史氏甲烷菌(M. smithii)数量减少(P<0.05),甲烷热杆菌(M. stadtmanae)数量增加(P<0.05),反刍甲烷杆菌(M.ruminantium)没有显著变化(P>0.05)。2)体外发酵模型中,与对照组相比,TS的添加量为10和15 g/L时,能够显著降低产气量(P<0.05)和发酵速率(P<0.01),减少原虫数量(P<0.01),进而抑制甲烷排放(P<0.01)。但在体内试验中,以上各项结果均不存在显著差异(P>0.05)。(结论)体外试验证明,饲粮中添加TS虽然没有改变甲烷菌总菌数量,但能够在一定程度上改变甲烷菌菌群结构,减少原虫数量,降低产气量,进而实现奶牛甲烷气体的减排。但体内试验中,TS的添加对奶牛瘤胃内甲烷菌没有显著影响。     

A calculation method for coalbed permeability by using drainage data

In order to more accurately calculate the changes in the permeability of coalbed during production process, a calculation method for coalbed permeability based on production data is established by combining with material balance equations and production equations, and it gives the fact that the output data can be a good reflection of the inner permeability of coalbed. The average pressure of coalbed in production process can be calculated through material balance equation. Dimensionless water production index is introduced into the production equation in the stage only with water production. In the next stage with both gas and water, gas and water production ratio is introduced to eliminate the influence of flush-flow radius, skin factor as well as other uncertain factors on the calculation of CBM permeability. The relationship between permeability and surface cumulative liquid production can be described as a single-variable cubic equation by derivation. There is a trend that the permeability declines firstly and then increases after wells in Qinshui CBM field are calculated. The results show that reservoir permeability increase after drainage stage, but the growth rate decrease gradually. The regression result of the permeability ratio and surface cumulative fluid production agrees with the theoretical mathematic relationship.     

水稻品种对稻田甲烷排放的影响

在大田条件下，应用甲烷自动测试系统在水稻生育期内持续测定3个水稻品种的甲烷排放通量。试验结果表明:水稻品种对稻田甲烷排放通量有明显的影响，品种间差异高达2.26倍；根量大的水稻品种，甲烷排放通量高，稻田气泡排放甲烷强度大，土壤水溶液中水溶甲烷浓度也高。试验证明，水稻根系的大小是导致水稻品种间甲烷排放通量差     

稻田耕作制度对CH4气体排放影响的研究进展

甲烷是重要的温室气体,其辐射增温效应是CO2的20~30倍。稻田是CH4的重要排放源之一。稻田CH4的排放是稻田CH4产生、氧化和传输综合作用的结果。影响稻田CH4释放的因素众多。本研究从水稻的农耕制度角度总结近年来关于稻田CH4排放的影响因素的研究,系统地归纳了水稻生物学特性、品种栽种方式、水肥管理等方面对CH4气体排放影响,同时从耕作角度提出了稻田CH4减排的技术措施。     

稻田甲烷排放与减排的研究进展

水稻作为最主要的粮食作物之一,对保证粮食供应和社会稳定起十分积极的作用。但稻田也是农田甲烷排放的主要来源,对全球温室效应有重要作用。从稻田甲烷排放机理、影响稻田甲烷排放的因素以及稻田甲烷减排的技术措施等方面综述了稻田甲烷的研究进展,并提出了未来开展稻田甲烷的研究方向,以期为进一步控制稻田甲烷排放提供一定参考。     

水稻植株甲烷传输能力与根系特性的相关性分析

为了探明影响水稻植株甲烷传输的关键根系特性,以推广面积较大的水稻品种为研究对象,在水培条件下研究不同品种水稻根系指标与甲烷传输能力的相关性。结果表明,与早稻甲烷传输能力呈极显著、显著正相关关系的根系指标分别是根系比表面积、根系活跃吸收面积,即早稻甲烷传输能力与水稻根系活力有显著正相关关系;与早稻甲烷传输能力呈极显著、显著负相关关系的根系指标分别是根重、最长根长。因此,根系活力较低、根重较大的早稻品种植株可能具有较弱的甲烷传输能力。     

多孔保鲜膜MA机理与数学模型研究

针对不同类型的保鲜膜气体分子吸附→溶解→扩散→解析的特征,研究分析了多孔保鲜膜MA机理,建立特征数学模型,从而为保鲜膜的研制和科学的使用奠定了理论基础.     

Character of Coalbed Methane Enrichment Controlled by Hydrological Geology in Libi Gorge Anticlines

The drain character and hydraulic linking are studied by analyzing the property of water-bearing and water-resisting, groundwater flowing and hydrochemistry character in Libi Gorge anticline. According this, the character of methane enrichment controlled by hydrological geology in the region is researched. It is indicated that Libi Gorge belongs to block anticline gas pool sealed by water pressure. In shallow layers, the water-bearing layers are controlled obviously by atmospheric water. The groundwater flows actively, drains nearby, but has no influence on the coalbed methane; in middle layers, the coal-bearing layers contain water weakly and the water flows slowly. The water has a roof and bottom enclosed effect on gas in water network ; in deep layers, the layers contain water weakly. The groundwater stops running and has a bottom enclosed effect on gas in water network. The most of faults are pressure faults, upper of them is water guiding, lower of them resisting. They enclose the gas by pressure. In addition, it is important for thickening rock character to enclose the gas.     

The Kinetic Study of Adsorption of Methane on Anthracite and Its Char

The adsorption quantities of methane on anthracite and its char at different tem-perature and time were measured by using volumetric niethod. The corresponding adsorption formula-is presented. The experimental results have shown that the diffusion acti-vation energies of methane in the anthracite and its char are 14.3 kJ/mol and 26. 3 kJ/mol.It issuggested that the diffusion process of methane could be the flow through the micropores in the an-thracite and its char.     

The Experiment of Prevention Accumulated Methane by Means of Abnormal Y Pattern Ventilation Method

In this paper, according to the experiment of abnormal Y pattern ventilation method in Coal Face 22160, Mine 10, Pingdingshan Coal Group Ltd. Co. , it is discussed that the effect of ventilation method on fugitive air and gas emission. It is discovered that Y pattern ventilation method can not only decrease air break in mine goaf by means of declining intake air in drawing road, and alleviate gas emission in gob area, but also wash the accumulated methane in upper corner by means of fresh air in middle road, and reduce the gradient of gas concentration greatly in direction of dip in upper half part of mining face and the gas concentration in upper corner. That can effectively prevent gas accumulation in mechanized high gas faces and provide reliable guarantee for high production and high effectiveness in mechanized high gas faces.     

Study on the Factors Affecting Gas Permeability of Coal

In this paper,the permeability of coal from Nantong colliery is studied in a labo-ratory. The effects of desorbed gas temperature and water content on gas permeability were investi-gated. The results of experiments indieatd that decreasing gas pressure without desorption , the permeability of coal decreases, However, below the desorption pressure, the permeability of coal formethane increases, The reaults suggest that the logarithm of permeability of coal is a linear functionof the temperature and the permeability of coal saturated with water is lass than the permeability ofdry coal; with the increase of water content, the permeability of coal for methane is increasing.     

Dynaical Mathematical Model of String

In the process of oil drilling, drilling string and rock bit are main drilling tools. The fact of their failure would cause serious accidents. To solve this problem, the vibration law of string should be found. The longitudinal vibration model, torsional model and lateral vibration model are founded simultaneity. Many methods are used to build up this model, including finite element technique, numerical technique and computer simulation. The dynamic model reveals the dynamic action of string, it is instructive to design new rock bit and study drilling mechanics.     

Adsorption and Seepage Characteristics of Coal to Methane under Electric Field

Based on two-phase anaerobic mechanism, a processing reactor was designed;and the waste water with high concentration discharged in the process of production of Chinese traditional medicine is carefully analyzed by the use of GC-MS.The results obtained in the experiment show that the by-products of hydrolization and acidification increase instead of the reduction of organic matters' sort,and at the same time that the number and the amount of compounds in the eventual processed water are apparently reduced,the acid-producing reactor may decompose compounds with great molecule into those with small molecule and accordingly improve the biologically processing ability.