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细菌能变残油为燃油最近,以色列科学家研制成了一种用生化技术制得的药剂,该药剂能除去油舱里残存下来的油,使其不污染海洋,而加药后生成的混合液可作为动力装置的燃油。他们还把此药称作乳化剂。罗森堡教授及其合作者于80年代发现：“吃油”细菌可用来作为环境“油拖把”,以消除油舱里残存的油。经过数年的试验,发现这种微生物分泌出一种非常强的生化清洁剂,在分析了它的化学组成后,他们制成了这种化合物,即乳化剂。当他们把乳化剂投入油舱时,油滴浮上水面,这种油滴的表面包上一层薄薄的乳化剂,成为稳定的油水乳化液。目前正在…     

单孔喷油嘴直喷式燃烧系统的初步研究

本文介绍一种新型单孔喷油嘴直喷式燃烧系统的初步研究结果。该燃烧系统的特点是在普通轴针式喷油嘴头部附加一个喷注挡块，从而使其改变方向并在撞击挡块时产生油滴的二次雾化，以达到加大喷注在空气中的散布面积，提高油与气混合速率的目的。试验是在一台多孔喷油直喷式燃烧系统的单缸柴油机上进行了。初步试验结果表明，该系统是可行的，并具有对燃油品质要求不高，工作可靠，起动性好等特点。与多孔喷油嘴式燃烧系统相比，目前该     

伞喷油雾与热多孔介质相互作用的数值模拟

为深入认识多孔介质发动机中均匀混合气的形成，用改进的KIVA-3V详细模拟了伞喷油雾与热多孔介质之间的相互作用．在KIVA-3V中增加了油滴碰撞热多孔介质壁面的碰撞模型、传热模型．为检测数值模型的合理性，在Senda等人的实验条件下进行了数值计算．油束碰壁后油滴和油蒸气分布的数值计算结果与实验结果吻合较好．在简化多孔介质结构的基础上和不同的环境压力及喷雾锥角时，模拟了伞喷油雾与热多孔介质的碰撞过程．计算结果表明，伞喷油雾的喷雾锥角及空间压力对油滴在多孔介质中的分布有着很大的影响，在多孔介质厚度一定时，通过调节这些参数，能够形成均匀混合气．     

细菌能变残油为燃油

最近，以色列科学家研制了一种用生化技术制得的药剂，该药剂能除去油舱里残存下来的油，使其不污染海洋，而加药后生成的混合液可作为动力装置的燃油。特拉维夫大学的科学家把此药称作乳化剂（Emulsan）。罗森堡教授及其合作者与八十年代发现，“吃油”细菌可用来作为环境“油拖把”，以消除油舱里残存的油。为了弄清楚细菌清扫油舱的机理，他们又做了数年的试验，发现这种微生物分泌一种非常强的生化清洁剂，在分析了它的化学组成后，他们制成了这种化合物，即乳化剂。当他们把乳化剂投入油舱时，油滴浮上水面，这种油滴的表面裹上一层薄…     

一种研究喷油嘴油束发展过程的新方法

介绍了一种利用动量的观点来研究燃油的喷射过程的方法，即根据动量定理，利用传感器测量油束撞击传感器上的力的来得到油束的瞬时动量，通过对一次喷油过程中的动量求和，使可计算出冲击到传感器上油束的总动量，通过在喷油泵试验台上实测的油束的运量，验证了燃油在喷射的过程中存在着后喷出的油滴赶上并超过前面的油滴的现象，并定量化分析了柴油机多孔式喷油嘴各油束之间的差别。     

空心喷雾油滴碰撞热多孔介质的数值研究

为加深对多孔介质发动机中均匀混合气形成的了解,用改进的KIVA-3V详细模拟了空心喷雾油滴碰撞热多孔介质的过程。在KIVA-3V中增加了油滴碰撞热多孔介质壁面的碰撞模型、传热模型及空心喷雾的线性不稳定性液膜破碎(LISA)模型。油滴与热壁的碰撞模型和传热模型经检验证明了其合理性。在简化多孔介质结构的基础上,在不同的环境压力及喷雾锥角下,模拟了空心喷雾与热多孔介质的相互作用。计算结果表明:油雾在碰撞到热多孔介质后,发生分裂的油束和多孔介质区域的高温,促使油滴实现快速蒸发并为油蒸汽与空气充分混合创造了前提。不同的空间压力及喷雾锥角直接影响到油滴在多孔介质中的分布。     

表面特性对含水多孔介质的气体扩散特性的影响

为研究多孔介质材料的表面特性即亲水性和疏水性对其含水状态下的扩散特性的影响,基于材料的气孔分布特性,利用材料表面特性不同其液态水充填方式的差异,分析了不同接触角对多孔材料在含水状态下扩散特性的影响。结果表明,不同表面性质的多孔材料其扩散特性差异很大,疏水性多孔介质的渗透性能和扩散性能均低于亲水性多孔介质。     

TiO2涂层自洁净玻璃的制备及其特性研究

采用Ｓｏｌ－ｇｅｌ工艺在玻璃表面制得均匀透明的多孔ＴｉＯ２纳米薄膜，其纳米颗 在小在５０－１００ｎｍ范围。该玻璃透光性较好，在可见光范围内相对于范围内相对于普通４玻璃的透光率在６３％以上，同时可以阻挡紫外线的透过。两种有机磷农药水溶液的光催化降解实验表明：随着镀膜次数的增加，光催化效率提高，当镀膜次数达到５次以上时，其光解率提高就比较缓慢。     

碰撞型喷油嘴在柴油机上的应用

本文介绍形成碰撞式油束，其部加一挡块的轴针式喷油嘴在柴油机上应用的试验研究。该喷油嘴的特点是自喷同的燃油直接撞击在部挡块上，以其改变喷束的方向并产生油滴的二次雾化，从而达到加大喷束在空气中散布面积，提高燃民空气混合速率的目的。初步的试验研究结果表明，这种喷油嘴用于涡流室式柴油机，可以降低其燃油消耗率和排因度；用于直喷式柴油机，可以取代多孔喷油嘴使发动机良 地运转，但与多孔式油嘴的直式燃烧系统相比，     

梯度多孔材料部分填充圆管强化换热的研究

基于GPM(梯度多孔材料)的优良特性,本工作设计了GPM部分填充圆管强化换热的结构。当Rp(多孔材料填充率)为0.8时,结合管内充分发展段的速度分布图、管内流动阻力系数和平均Nu数,分别研究了dp(填充梯度孔径)多孔材料、ε(梯度孔隙率)多孔材料对于管内流体流动以及传热特性的影响规律,并将其与HPM(均匀多孔材料)填充圆管时的结果做了对比分析。在此基础上,比较了各种多孔材料填充结构的换热与流动综合评价性能(简称PEC)。结果表明,通过合理设计GPM的结构,能够在强化换热的基础上,有效地降低圆管流动阻力,从而得到较好的综合评价性能(PEC)。     

Combustion of liquid fuel inside inert porous media: an analytical approach

This paper presents a numerical analysis of combustion of liquid fuel droplets suspended in air inside an inert porous media. A one-dimensional heat transfer model has been developed assuming complete vaporization of oil droplets prior to their entry into the flame. The effects of absorption coefficient, emissivity of medium, flame position on radiative energy output efficiency and optimum oil droplet size at the entry, defined as the maximum size for complete vaporization before entering the combustion zone, have been presented. The inert porous medium with low absorption coefficient will produce high downstream radiative output with large oil droplet sizes.     

杜84块兴Ⅵ组油水界面认识研究

杜84块兴Ⅵ组油层以蒸汽吞吐开发为主,后期将转入直平组合SAGD开发。该油层埋深范围-710~-840m,以厚层块状为主,厚度一般在30~80m,油水关系复杂,为底水油藏,已进入中后期开发阶段。兴Ⅵ组共有直井382口,水平井54口。目前已转入SAGD生产的直井有143口,水平井有21口,累计注汽480.4×104t,累计产油76.1×104t,累计产水403.3×104t,油汽比为0.16,日产液为4118.9t/d,日产油为545.8t/d,含水达到86.7%。兴Ⅵ组油层油水关系复杂,个别直井和水平井长期高含水生产,影响整体开发动用效果。通过测井资料,从电性和物性上深入研究兴Ⅵ组底部油水界面,建立统一的油水识别标准,并借助钻井取心、生产动态资料进一步验证,确定全区油水界面。运用新技术对油水发育进行三维地质建模,为后期兴Ⅵ组整体开发及转入SAGD开发后提供可靠依据。     

Numerical method for interfacial heat transfer in an oil-water displacement flow

A numerical study of interfacial heat transfer is performed in an oil-water displacement flow. The process of oil-water displacement is one of the key technologies for the underwater tank in offshore oil exploitation. There is a need to investigate the interfacial heat transfer between oil and water as the wax precipitation and solidification of high pour point crude oil at low temperature will particularly affect the flow of oil. Before the numerical simulation is performed, it is necessary to find out the optimal numerical method. For the volume of fluid method, the property parameters in the temperature equation are mixture ones weighted by each fluid. When the unsteady term, convective term, and diffusion term are considered, there are three property parameters that are the coefficient of each term. For each coefficient, whether an algebraic scheme or a harmonic scheme could be used. When the three coefficients are considered together, there would be eight combinations of weighting form. A numerical method is developed by exploring an optimal combination of the weighting form. The results are demonstrated with an analytical solution. It is found that the combination of three harmonic schemes will significantly improve the error. The maximum and total error from this combination are reduced by 62% and 79% compared to the second-best one and by 86% and 93% compared to the worst one. Meanwhile, the clock time only increases by 1.6% and 0.4%. The combinations of three harmonic schemes will result in the largest order of accuracy which is as large as 1.60. The harmonic scheme should be used for the property parameter of all the three terms in the vertical oil-water flow.     

高含水采油期油气水混输水平管路压降试验研究

随着油田开发的不断深入,大庆油田原油综合含水不断提高,许多区块的水的质量分数已达到90%,有的甚至达到或超过了95%.由于缺乏对特高含水采油期油气水混输水平管路压降的研究,制约了高含水采油期不加热集输规模的扩大.针对大庆采油六厂高含水采油期油气水混输管道,设计了一套试验装置,试验研究高含水采油期油气水混输水平管路压降.对试验测试数据进行了回归处理及分析,得出了百米压降及油气水三相压降与油水两相压降的关系.     

汽油单液滴撞击不同壁面试验研究

为明确汽油单液滴撞壁特性,设计了单液滴撞壁系统,分析了汽油液滴撞壁现象及不同壁面对汽油液滴撞壁结果转捩的影响。研究表明:汽油液滴撞击干壁面时在壁面粘附铺展成一层附壁油膜,附壁油膜促使液滴再次撞壁时发生皇冠射流飞溅现象。附壁油膜越薄,飞溅越剧烈,飞溅持续时间越短。相比硅油膜动力黏度,硅油膜厚度对汽油液滴撞壁后形态演变过程影响更大。汽油液滴撞击硅油膜会稀释硅油膜,稀释前后射流分别为碗状射流、皇冠状射流。随着稀释程度增加,皇冠状射流的二次液滴数量增加,二次液滴中含有壁面硅油组分。无量纲时间τ1时,Rioboo模型能较好地预测铺展因子变化规律,但若超过此时间则Rioboo模型预测不准。     

Modelling of a porous flowing electrolyte layer in a flowing electrolyte direct-methanol fuel cell

The flowing electrolyte-direct methanol fuel cell is a developing technology that may have practical uses in the future. Its main advantage over a direct methanol fuel cell is that it limits methanol crossover using a flowing electrolyte layer. The flowing electrolyte layer (or flowing electrolyte channel) involves an ion-conducting fluid that allows protons to be transported from the anode to the cathode, and flows through a porous material to wash away crossed-over methanol. In this study, the flowing electrolyte layer is modelled as a porous domain in ANSYS CFX. General flow behaviour and the effects of volume flux, channel thickness, and porous material properties are investigated. It is found that the flow has a flattened velocity profile with thin boundary layers that are virtually independent of volume flux and channel thickness. The pressure drop is mainly dependent on the volume flux and the permeability. It is recommended that cell performance could be improved by using a flowing electrolyte channel that is thinner, and selecting a sufficiently high volume flux and a sufficiently permeable porous material to achieve an optimal combination of pressure drop and methanol removal characteristics.     

Multiobjective optimization study of jet impingement heat transfer through a porous passage configuration

The present study reports an optimized configuration of multijets impinging through porous passages, providing a viable solution for applications requiring localized heat transfer. The cascaded collision lattice Boltzmann numerical method is initially validated with the in-house experimental results of single jet impinging through a porous passage configuration. A multiobjective optimization study using Kriging-GA algorithm is conducted on a single jet impinging through a porous passage at a Reynolds number of 400, considering Darcy number, porosity, and porous passage height as variables and Nusselt number, nondimensional pressure drop as the conflicting objectives. The optimal parameters from the generated pareto plot are chosen attributing equal weightage to Nusselt number and nondimensional pressure drop. Finally, an optimal pitch for multijets impinging through optimized porous passages is determined to maximize heat transfer performance.     

锅炉水质安全与节能

锅炉作为能源消耗大户,其节能、节水十分重要。通过对锅炉水质的软化以及提高蒸汽凝结水的回收率,可收到较好的节能降耗效果,冷凝水回收率在80%时,每年可节约燃料油470t,每年再生剂用量从200t降到140t左右。     

一种新型水滴迷宫式调节阀流场特性研究

针对超(超)临界工况下调节阀压降大、流速高的特点,以传统迷宫碟片式调节阀为基础,提出一种新型水滴迷宫式碟片调节阀。利用Fluent软件进行数值模拟,研究阀门在不同开度下的流通性能及不同水滴级数对阀门降压控速能力的影响。研究表明,新结构碟片流通性能良好,可以满足阀门工作条件要求,增加水滴级数会降低阀门流通性能;随着水滴级数的增加,各级水滴间的压降和阀内流速均呈现减小的趋势,五级水滴介质平均压降为5.08MPa,比二级水滴降低了6.26 MPa;最大速度为108m/s,降低了40%;碟片流道出口处存在气蚀现象,水滴级数的增加可减小气蚀区域。     

MRI investigation of the evaporation of embedded liquid droplets from porous surfaces under different drying regimes

A combination of in situ one-dimensional ¹H magnetic resonance profiling and two-dimensional imaging has been applied to study the shape and subsequent dynamic evaporation behaviour of a single liquid droplet after impact onto a porous surface. Diethyl-malonate (DEM) droplets are initially embedded in the porous substrate by impingement, and are then evaporated over a period of several hours; the surface of the substrate being ventilated by a controlled airflow. The configuration is intended to mimic the behaviour of droplets evaporating into atmospheric flows. In order to evaluate the influence of the airflow at the surface of the porous medium, different experimental configurations were tested by varying the speed of the airflow stream above the porous surface. The method produces several types of data, including images of impinged droplets inside the porous substrate and their development with time during the evaporation episode, one-dimensional concentration profiles through the substrates, and corresponding estimates of the mass fraction of liquid remaining, evaporation rate and mass flux per unit area. The results obtained show that although liquid droplets tend to evaporate faster and present larger evaporation rates when exposed to a more efficient removal of vapour from the surface, the limiting effects of the porous medium are even more evident.