高压气体在膜式螺旋管环形通道中的对流换热特性

在加压的条件下试验研究了膜式螺旋管环形通道内的对流换热特性,试验气体有单质气体He和N2,也有混合气体如He+N2,试验压力为0.5～3.5 MPa,给出了不同螺旋管结构、不同气体和压力下的对流换热系数,以及典型冲刷形式的对流换热关联式及其适用条件.试验研究表明,气体压力、气体组分、冲刷形式对换热系数均有影响,特别是气体压力的影响最为突出.由数据分析得出了膜式螺旋管环形通道的对流换热关联式,该关联式可以适用于各种气体成分.     

民用煤燃烧污染物排放因子研究

根据自行设计的模拟燃烧-稀释通道采样系统,选用河南、山西、陕西和武汉不同煤种模拟民用燃煤的不同燃烧状态,采集了2种烟煤、2种无烟煤、2种蜂窝煤和1种型煤燃烧排放的颗粒物和气态污染物。将不同煤种燃烧排放物进行了对比分析,结果表明:明烧时不同煤种燃烧排放颗粒物差异明显,烟煤燃烧PM_(10)排放因子明显高于无烟煤和蜂窝煤;燃煤PM_(10)排放因子与燃煤挥发分含量相关。不同煤种燃烧时气体污染物排放因子与煤的形态无明显关联,SO_2排放与燃煤硫含量正相关。不同燃烧状态对燃煤气体污染物排放影响不明显。     

新疆低渗透油田注气提高采收率技术筛选(英文)

针对新疆低渗透油藏,利用油藏数值模拟技术筛选不同注气提高采收率方案,包括CO2、空气、N2和烟道气,评价其技术和经济的可行性。采用改进的Corey模型计算各种气体在不同混相条件下的开发效果,重点分析温室气体CO2的埋存及提高采收率机制。在无廉价气源条件下,可以选取注空气低温氧化技术,直接注入电厂排放的烟道气也是一种不错的提高采收率技术并可减少温室气体的排放,但烟道气运输成本过高。通过可行性分析认为,不同注气开发方案在技术上是可行的,但在经济上受到一定限制。     

信湖3煤抽提后低温氧化特性变化实验研究

为了研究煤中低分子化合物对煤低温氧化规律的影响,选用四氢呋喃溶剂对信湖3煤进行微波辅助抽提,通过低温氧化实验,测试了煤样抽提前后煤体耗氧特性及气体产物释放规律。结果表明,抽提前后煤样在低温氧化过程中产生的气体主要有CO、CO_2等气体氧化产物和CH_4、C_2H_4、C_2H_6、C_3H_8等烷烃类气体,煤样抽提后这些气体的产生量均有不同程度的降低;抽提后残煤的耗氧量和耗氧速率明显要低于抽提前原煤。可见,煤中低分子化合物的存在对信湖3煤的自燃有一定的促进作用。     

天然气中SF_6等多种氟化物气体示踪剂的气相色谱检测

为了监测气驱油藏中的气体示踪剂,利用GC/ECD建立了一种分析天然气中多种氟化物气体示踪剂的方法。该方法选用GDX-104色谱柱,排除了样品中空气峰对检测的干扰,通过正交试验优化最低灵敏度组分的检测条件,并以此作为同时检测天然气或空气中多种气体示踪剂(SF_6、CF_2Br_2和C_4F_8)的条件,其中SF6、CF_2Br_2和C_4F_8的检出限分别为1×10~(-6)、1×10~(-5)和1×10~(-3)μg/L,重复进样7次的相对标准偏差不大于7%。通过对中原油田天然气驱油藏的气体示踪剂的监测,得到了示踪剂的产出曲线,弄清了该区块的非均质性和注采井的连通关系。该检测方法快速、简便,所需样品量少,可实现多种示踪剂同时检测,不仅适用于天然气中微量气体示踪检测,而且适用于大气环流的微量气体示踪检测。     

生物滴滤塔处理含H_2S气体的实验研究

选用陶粒,阶梯环,陶瓷锯鞍环,金属锯鞍环,粉煤灰块五种填料分别装入生物滴滤塔进行进行处理含H2S气体的实验研究。从气体入口浓度,营养盐喷淋量和气体流量三个方面探讨了其与H2S气体处理效率之间的关系。     

焊缝气孔缺陷的形成原因及防治措施

焊接制造技术是一门理论性和实践性较强的综合性技术。论述焊缝气孔缺陷的类型及形成条件，如何限制熔池溶入或产生气体以及排除熔池中存在的气体，选用与母材匹配的焊接材料，制定并控制焊接工艺条件，可以有效的控制焊接工程中的气孔缺陷的产生。     

介电泳操控不同基团修饰多壁碳纳米管气体传感器对SO_2的气敏性能

利用介电泳法在铬-银-金微电极上制备了本征多壁碳纳米管(MWNTs)气体传感器及不同基团修饰多壁碳纳米管(MWNTs-x,x:NH2,OH,COOH)气体传感器,考察了MWNTs和MWNTs-x在非均匀电场中的介电响应行为,将8 V,2 MHz的电泳参数确定为多壁碳纳米管气体传感器的制备条件;在介电泳力作用下MWNTs和MWNTs-x的颗粒均被捕获到电极尖端,发生了正介电泳(p-DEP).室温下研究了制备的气体传感器对不同浓度二氧化硫(SO2)的气敏性能,研究发现传感器对SO2的响应时间、恢复时间和灵敏度随SO2气体浓度的增加而增大,不同基团修饰MWNTs气体传感器对SO2的灵敏度较本征MWNTs传感器的灵敏度显著提高,氨基修饰MWNTs(MWNTs-NH2)气体传感器的灵敏度最高,为本征MWNTs气体传感器的17–23倍,碳管与SO2间的毛细力、表面张力、氢键、化学键等相互作用为影响传感器气敏性能的因素.     

煤炭自燃火源探测示踪气体的筛选研究

本文通过对SF_6、CF_2ClBr、CF_2Br_2、CF_2Cl_2四种气体的色谱分析研究,探讨了它们在电子捕获检测器、5A分子筛柱上的响应特性,并根据煤矿井下实际,最终优选出SF_6和CF_2ClBr两种示踪气体。同时实验研究了分析SF_6和CF_2ClBr示踪气体的色谱操作条件,提出了最佳色谱操作条件。     

纳米TiO2的流化床渗氮反应

研究了气固流化床中TiO2渗氮反应的工艺条件。通过小型冷模实验比较了不同气速下包裹型纳米TiO2床层的流化状态和膨胀情况,依据流化情况选择了操作空速;通过热模实验在不同反应温度、反应时间、反应气体等工艺条件下进行了渗氮反应,测试了产品TiO2-xNa对SO2的气相降解率,并进行了XRD,UV-Vis分析,据此得到较佳的反应温度为400℃、而反应时间与气体组成对反应的影响不大,并根据XPS结果推测了渗氮机理。     

非煤系地层隧道围岩有害气体形成机制

大量在建和拟建隧道面临非煤系地层有害气体的挑战，厘清非煤系地层隧道围岩有害气体形成机制是解决该问题的基础。基于此，综述了我国非煤系地层隧道围岩有害气体形成机制研究的最新进展，总结了非煤系地层有害气体主要类型，探讨了地质条件对于有害气体形成的影响机理，分析了有害气体的孕育机制，展望了非煤系地层隧道有害气体问题的研究方向。研究表明：非煤系地层隧道有害气体大体可按照成因分为构造连通型、围岩变质型和综合成因型；大型断裂、褶皱及深部循环的水热型高温导热带等地质构造对非煤系地层隧道围岩有害气体的形成、赋存和溢出起到关键作用；CH4、H2S和CO2等的来源相似，但物理化学性质的差异导致其形成机制不同；复杂地质构造、复合组分隧道围岩有害气体的孕育及运移模式、固-液-热-力多场耦合机制等方面值得进一步研究。研究对于非煤系地层隧道围岩有害气体防治的实践和研究具有积极意义。     

Groundbreaking gas source rock correlation research based on the application of a new experimental approach for adsorbed gas

Many years of experimentation have led to the development and improvement of equipment and methods used to make gas source rock correlations.By crushing samples using a ball mill and directly collecting adsorbed gases in the absence of aqueous media under high vacuum conditions,most possible interference factors,such as atmospheric pollution,crushing-induced pyrolysis,and gas collection by aqueous media are eliminated.This greatly enhances the volume percentage of hydrocarbon gas in the acquired adsorbed gases,with maxima up to more than 80%.The actual measurement of carbon isotopic series can be carried out to such an extent as to be δ13C1-δ13C5.A preliminary study using newly established equipment and methods has indicated the following.(1) The carbon isotopic composition of ethane in adsorbed gases on hydrocarbon source rocks can be used to distinguish the types of source rocks.This is consistent with results obtained by using organic geochemical parameters for source rocks,and illustrates that it is highly feasible to use the carbon isotopic composition of ethane in natural gases as a parameter for distinguishing the types of source rocks.(2) The thermal evolution degree(Ro) of hydrocarbon-source rocks calculated in terms of the carbon isotopic composition of methane in adsorbed gases on hydrocarbon source rocks agrees well with the vitrinite reflectance actually measured in the source rocks.This confirms the reliability of the relationship between the carbon isotopic composition of methane in natural gases and the thermal evolution degree determined using statistics.(3) Finally,a direct gas source correlation method for natural gases has been established,and the expression of log Ro vs.δ13C1 established in terms of actually measured δ13C1 values of methane in absorbed gases.Ro values of hydrocarbon source rocks have been established as well,thus creating favorable conditions for precise oil-and-gas source correlations in exploration areas.     

Discussion of gas enrichment mechanism and natural gas origin in marine sedimentary basin,China

There are abundant natural gas resources in Chinese marine sedimentary basin. The exploration hot shots of natural gas are the Palaeozoic marine strata here in recent years, and several large scale gas fields have been discovered. Chinese Palaeozoic high-post matured and coal measure hydrocarbon source rocks are mainly prone to gas generation in the present. This research considered that gas source rocks and TSR are the key cause of gas enrichment of marine strata. High-quality argillaceous and coal measure hydrocarbon rocks are distributed widely in the Palaeozoic marine strata, which have been in highly matured phase in the present. The argillaceous source rock generally contains various sulfates that could accelerate crude oil cracking to gas for TSR occurrence, and coal measure source rock mainly generates gas, so Chinese marine basin gives priority to accumulating gas. Marine strata have not founded oil reservoirs in the Sichuan Basin and Ordos Basin, and they consist mainly of dry gas. Marine natural gases are the mixed gases of oil cracking gas and coal-formed gas in a general way, oil cracking gases contain usually some H2S and CO2. Hydrocarbon carbon isotopes are very complicated, and methane and ethane isotopic values bear apparent reversal caused by thermal evolution and mixing among different genetic types of natural gas. Coal-formed gases are the main component of Chinese marine natural gas. The Upper Permian of the Sichuan Basin and the Carboniferous-Permian of the Ordos Basin coal measure hydrocarbon source rock present large hydrocarbon generation potential, which are the prospecting highlight of marine natural gas hereafter. Oil cracking gas exploration will be paid much attention to in the Tarim Basin because of the lack of coal measure hydrocarbon source rock.     

Characteristics of gas geochemistry in Yangbajing geothermal field, Tibet

CO 2 is a main component of gases in the Yangbajing geothermal field, usually higher than 85 in volume; others are N 2, H 2S, H 2, CH 4, etc. Helium R/R a ratios, ranging from 0.14 to 0.46, indicate a crustal component to be dominant in the gases. δ 13C-CO 2 values and δ 34S-H 2S values are in the range -7.72‰--11.33‰ and 0.2‰-8.3‰, respectively. The gases are inferred to mostly derive from the partial melting of the Nyainqentanglha core complex. The gases of shallow and deep reservoirs are distinctive in chemical compositions and δ 34S-H 2S values, which shows their different flowing paths and physical-chemical processes. Sulphur does not approach isotopic equilibrium between H 2S and SO 2- 4 species in both reservoirs. Significance of steam chemical monitoring is also discussed.     

Discussion of gas enrichment mechanism and natural gas origin in marine sedimentary basin, China

There are abundant natural gas resources in Chinese marine sedimentary basin. The exploration hot shots of natural gas are the Palaeozoic marine strata here in recent years, and several large scale gas fields have been discovered. Chinese Palaeozoic high-post matured and coal measure hydrocarbon source rocks are mainly prone to gas generation in the present. This research considered that gas source rocks and TSR are the key cause of gas enrichment of marine strata. High-quality argillaceous and coal measure hydrocarbon rocks are distributed widely in the Palaeozoic marine strata, which have been in highly matured phase in the present. The argillaceous source rock generally contains various sulfates that could accelerate crude oil cracking to gas for TSR occurrence, and coal measure source rock mainly generates gas, so Chinese marine basin gives priority to accumulating gas. Marine strata have not founded oil reservoirs in the Sichuan Basin and Ordos Basin, and they consist mainly of dry gas. Marine natural gases are the mixed gases of oil cracking gas and coal-formed gas in a general way, oil cracking gases contain usually some H2S and CO2. Hydrocarbon carbon isotopes are very complicated, and methane and ethane isotopic values bear apparent reversal caused by thermal evolution and mixing among different genetic types of natural gas. Coal-formed gases are the main component of Chinese marine natural gas. The Upper Permian of the Sichuan Basin and the Carboniferous-Permian of the Ordos Basin coal measure hydrocarbon source rock present large hydrocarbon generation po- tential, which are the prospecting highlight of marine natural gas hereafter. Oil cracking gas exploration will be paid much attention to in the Tarim Basin because of the lack of coal measure hydrocarbon source rock.     

Influence of laser doping on nanocrystalline ZnO thin films gas sensors

The effect of laser doping of Al on the gas sensing behavior of nanocrystalline ZnO thin films is reported. The doping of Al was carried out by the spin-coating of Al-precursors on nanocrystalline ZnO films followed by a pulsed laser irradiation. The laser-doped films were characterized as a function of laser power density by measuring the optical, structural, electrical, morphological and gas sensing properties of ZnO films. It was found that the laser doping process resulted in an increase of electrical conductivity of ZnO films. The performance of gas sensor was investigated for different concentrations of H2 and NH3 in the air. The results indicate that the laser doping process can be utilized to improve the sensor characteristics such as sensitivity and response time by optimization of laser power density. The optimum laser power is interpreted as the critical power level required to compete the effective doping versus developing the effective grain boundaries. Also, the selectivity of laser-doped ZnO sensors for H2 was studied for a likelihood practical gas mixture composed of H2, NH3 and CH4. It is found that these films can be optimized to develop H2 and NH3 sensors in PPM level with a higher selectivity over other reducing gases.     

甲醛气体传感器的研究

以纳米材料SnO_2、Zn O为原料的气敏传感器对大多数VOC气体具有敏感性.以SnO_2和ZnO为基料制作旁热式甲醛气敏元件,并比较二者的气敏特性.选用对甲醛敏感的SnO_2材料作为元件基料,为改善其对甲醛的气敏特性,选择0.3%La_2O_3、0.5%La2O3、0.7%La_2O_3的3种比例掺杂,运用控制变量法分别在不同烧结温度和不同工作温度下进行测试.结果表明:掺杂0.3%La_2O_3的SnO_2气敏元件在烧结温度为700℃,工作温度为300℃下对甲醛的气敏特性良好.     

Thermal simulation of the formation and evolution of coalbed gas

Thermal simulation experiment of gas generation from the peat and the coals were performed using the high temperature and pressure apparatus, at temperature ranging from 336.8-600℃, a pressure of 50MPa and two heating rates of 20℃/h and 2℃/h, and the evolution and formation of coalbed gas components were studied. Results show that for the coals, the gaseous products are mainly composed of hydrocarbon gases. However, for the peat the content of hydrocarbon gases in gaseous products is lower than that of non-hydrocarbon components. In the generated hydrocarbon gases methane is predominant and heavy hydrocarbon gases (C2-5) are present in small amount. Meanwhile, carbon dioxide (CO2) predominates the generated non-hydrocarbon gases, and hydrogen (H2) and sul-furated hydrogen (H2S) are existent in trace amount. It is also observed that temperature is the main factor controlling the evolution of coalbed gas generation. With increasing vitrinite reflectance, methane rapidly increases, CO2 sightly increases, and C2-5 hydrocarbons first increase and then decrease. The peat and Shanxi formation coal have a higher generative potential of coalbed gases than coals and Taiyuan formation coal, respectively, reflecting the effect of the property of organic matter on the characteristics of coalbed gas component generation. In this study, it is found that low heating rate is favorable for the generation of methane, H2 and CO2, and the decomposition of C2-5 hydrocarbons. This shows that heating time plays an important controlling role in the generation and evolution of coalbed gases. The results obtained from the simulation experiment in the study of coalbed gases in natural system are also discussed.     

变压器油纸绝缘沿面放电特性及其产气规律

基于油纸绝缘沿面放电模型,在实验室模拟变压器油箱内进行局部放电试验,研究油纸绝缘沿面放电发展特性及其特征量的变化规律,并着重研究放电发展过程中油中溶解气体的变化特性。实验结果表明,油纸绝缘沿面放电幅值在放电起始阶段呈上升的趋势,放电2～3h幅值达到最大,然后放电强度开始慢慢减弱;随着油纸绝缘局部放电的发展,CO的绝对产气速率以一个值为中心上下波动,变化幅值较小;而油中沿面放电H2和CH4的绝对产气速率先增加再减少,放电谱图变化与油中溶解气体绝对产气速率变化表现出较高的相似性。     

基于应变角度分析N_2和CO_2对煤层透气性的影响

为深入了解煤在注入提高煤层气产能的N2、CO2气体后,煤的应变及透气性系数的变化情况,采用实验的方法研究了注入N2、CO2气体后应变的变化及对透气性系数的影响。结果表明:煤对氮气的透气性系数最高,其次是甲烷,再次是二氧化碳。这与煤对二氧化碳的吸附能力最强,甲烷次之,氮气最弱是相一致的,然而,注入三种气体煤样所产生的应变变化比例与透气性变化比例却不尽一致。因此,从应变角度建立的对透气性系数影响的分析模型,对于注入N2、CO2后透气性系数变化的分析适用做进一步研究。