天然气大气式灶具的CO排放特性预测

CO是城市燃气燃烧过程中生成的主要污染物之一,必须对其排放量进行严格的控制。随着我国气源多样化格局的形成,不同组分的天然气在同一管网中运输,可能会引发末端设备的互换性问题,造成CO排放量的不稳定。为此,通过实验分析了天然气组分与大气式灶具CO排放特性之间的关系,并提出CO排放特性的预测公式。实验分为3个阶段:(1)在设计的大气式基准燃烧器上,测试了2 kPa条件下CH_4掺混单一组分时CO的排放特性,确定了C_2H_6、C_3H_8、C_4H_(10)、N_2和H_2各自对CO排放量的影响;(2)进行以CH_4为主要成分的多组分随机掺混配气CO的排放实验测试,并对实验结果进行多元线性回归分析,确定CO排放量与天然气各组分含量之间的数学关系;(3)选取3台结构型式具有代表性的实际天然气灶具,进行不同组分天然气的CO排放特性测试,验证提出的数学关系式的通用性。实验验证结果表明:实验回归得到的计算公式具有一定的通用性,可以很好地预测天然气组分变化时燃烧器的CO排放性能。     

Circumventing fuel-NOx formation in catalytic combustion of gasified biomass

It has been shown that it is possible to decrease fuel-NO_x produced from NH₃ using catalytic combustion of a synthetic gasified biomass at fuel-lean conditions. In a certain temperature regime where the conversion of fuel components, such as CO, H₂ and CH₄, is low and conversion of NH₃ is high, it is suggested that the formed NO_x is reduced by the remaining fuel components, mainly hydrocarbons. With oxide catalysts only ca. 10% of the NH₃ was converted to NO_x, the rest to N₂. It has also been shown that the ignition sequence of CO, H₂ and CH₄ varied for different catalysts and different experimental conditions, and that methane coupling and methanation reactions occurred before ignition of CH₄.     

Development of thin‐film composite membranes for carbon dioxide and methane separation using sulfonated poly(phenylene oxide)

Novel membranes based on sulfonated poly (phenylene oxide) (SPPO) was developed. SPPO membranes in the hydrogen form were converted to metal ion forms. The effect of exchange with metal ions including monovalent (Li⁺, Na⁺, K⁺), divalent (Mg²⁺, Ba²⁺, Ca²⁺) and trivalent (Al³⁺) ions was investigated in terms of permeation rate and permeation rate ratios for CO₂ and CH₄ gases. Both dense homogeneous membranes and thin‐film composite (TFC) membranes were studied for their gas separation characteristics. The effect of membrane preparation conditions and operating parameters on the membrane performance were also investigated. The selectivity of the TFC membrane increased as the cationic charge density increased as a result of electrostatic cross‐linking. TFC membrane of very high selectivity was achieved by coating a thin layer of SPPO‐Mg on a PES substrate. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 735–742, 2000     

德国污泥处置技术的分析与研究

分析德国的污泥处置技术,旨在对我国的污泥处置方式进行改进．德国采用的污泥处理技术为：污泥消化发酵产甲烷气用于发电;消化后的污泥,利用垃圾焚烧厂烟气废热干燥,干燥的污泥颗粒作为燃料用于发电厂或水泥厂,或直接作为燃料应用于发电厂．但是,在甲烷气进入发电机前,首先必须对其采用活性炭吸附技术净化,净化后可保证含Si有机物质量分数小于0．6mg／L;不然,该物质将对发电机正常运行造成危害．研究表明,德国技术在我国的应用是可行的、实用的．     

基于可调谐半导体激光吸收光谱技术的甲烷气体监测研究

设计了一种基于可调谐半导体激光吸收光谱技术的甲烷(CH4)气体监测装置,该装置具有温度监测范围大、监测精度高和实时监测的优点。监测装置的激光光源为波长1650 nm的反馈式激光器,应用波长调谐与锁相放大器技术,对周围环境进行温度补偿与背景扣除,可以较准确地测量周围环境中CH4的体积分数。实验表明,当CH4体积分数小于1%时,该装置的监测精度为±0.02%;当CH4体积分数大于1%时,装置监测误差小于±0.8%,实时监测的最长响应时间为10 s。装置的温度范围为0~40℃,可满足大多数工业生产中对CH4等气体体积分数的监测需求。     

钙钛矿敏化太阳电池制备工艺的优化研究

近年来,有机金属卤化物钙钛矿太阳电池因制备条件温和、光吸收强、能耗低、光电转化效率高等优点成为备受瞩目的研究热点。本文采用一步法制备钙钛矿材料甲胺碘化铅（CH3NH3PbI3）,并以廉价的聚（3-己基噻吩） （P3HT）为空穴传输材料在大气环境下制备钙钛矿敏化太阳电池。其中,通过调控TiO2浆料与松油醇、乙基纤维素的配比,分别制备具有250 nm、600 nm和1 000 nm三种不同厚度的TiO2纳米颗粒多孔薄膜光阳极,并系统考察钙钛矿前驱体溶液旋涂量对敏化电极结构形貌及光吸收性能的影响。太阳电池光电特性测试结果表明：当TiO2多孔层厚度为600 nm、钙钛矿前驱体溶液的旋涂量为40 μl时,CH3NH3PbI3能够较为完全地覆盖在多孔TiO2的表面,且钙钛矿材料的晶粒尺寸合适,TiO2孔道结构未被堵塞,有利于空穴导体的填充以及空穴的转移与传输,优化后的太阳电池光电转化效率达到5.17%。     

量热法多孔沉积物内CH4水合物生成过程中的放热行为

掌握天然气水合物在多孔沉积物生成过程中的放热规律对于天然气水合物的资源开发和了解水合物的成藏规律都具有重要意义。本研究通过高压微量热仪考察了石英砂粒径、初始含水率、温度及含盐条件对CH₄水合物在多孔沉积物内生成过程中放热行为的影响。实验结果表明,随着石英砂粒径的减小,水合物生成的放热速率随之增加。随着初始含水率的降低,水合物的放热峰明显增大,但在实验考察时间内,最终的累积放热量和含水率并没有呈现出明显的相关性。当温度在263.15K时,CH₄水合物生成过程中不存在明显的放热。对于在3.35% NaCl盐溶液体系中进行的甲烷水合物生长放热实验,发现其放热规律与在纯水体系下的放热规律具有较高的一致性,但其总体放热速率和累积放热量较纯水体系更低。实验结果呈现了良好的规律性,对进一步开发量热仪在水合物生成动力学方面的应用具有一定的参考价值。     

MWD GAMMA 测量技术在地质导向钻井中的应用

MWD GAMMA测量是MWD无线随钻仪在完成井眼井斜、方位、工具面等定向参数测量的基础上,对MWD仪器的GAMMA测量功能加以开发应用。地质人员利用测量的地层自然伽马值可以及时分析地层岩性变化,进行地层对比,为地质决策提供科学的参考。目前,该技术已在濮侧平130井和桥69-平1井得到了成功应用。     

基于二阶矩封闭湍流模型的非预混湍流火焰的数值模拟

Turbulent nonpremixed CH4/H2 flame has been simulated using several typical differential secondmoment turbulence closure (SMTC) models. To clarify the applicability of the various models, the LRR-IP model,JM model, SSG model as well as two modified LRR-IP models were tested. Some of above-mentioned SMTC models cannot provide the overall satisfactory predictions of this challenging case. It is confirmed again that the standard LRR-IP model considerably overpredict the centerline velocity decay rate, and therefore performs not well. Also it is interesting to observe that the JM model does not perform well in this challenging test case, although it has already been proved successful in other cases. The SSG model produces quite satisfactory prediction and performs equally well or better than the two modified LRR-IP models in the reacting case. It can be concluded that the modified LRR-IP models as well as the SSG model are superior to the other SMTC models in the turbulent nonpremixed CH4/H2 flame.     

基于ADuC834单片机的瓦斯气体检测仪的设计

介绍了一种基于ADuC834单片机的瓦斯气体检测仪硬件结构与软件设计的方法,该检测仪采用传统的黑白元件作为传感器来实现对瓦斯气体的检测,整个检测仪具有体积小、功耗低、A／D转换速率快及良好的应用前景等特点。