进口糊树脂单体泵机械密封失效分析及改造

针对进口糊树脂单体泵在特定使用工况条件下所造成的机械密封失效进行分析,提出了机械密封的改造方案,改进了弹簧的形式并采用浮装结构,解决了机械密封的短期失效问题。     

重整循环氢压缩机干气密封改造

通过干气密封在连续重整装置改造成功的实例,阐述了浮环密封使用的缺陷、干气密封的工作原理、改造过程、运行情况及改造后的经济效益。     

氮肥厂脱硫循环泵的改造

针对中、小型化肥厂生产中脱硫循环泵泄漏的问题,分析了造成泄漏的主要原因是机械密封的动、静环失效与弹性压紧元件的失效或由于种种原因造成的动环比压不足。提出了通过改变动、静环材料,提高压紧元件比压,防止弹性元件失效等措施,改进离心泵的密封结构,改善机械密封的工作环境,使脱硫循环泵的泄漏问题得到了解决。     

石油化工泵备用机械密封及报警系统的研究

为防止和监控关系泵用机械密封的突然失效，研制了备用机械密封及提警系统，该系统是在主密封后面安装一个非接触式备用机械密封，主密封与备用密封间有一个辅助密封腔，与压力报警装置相连，当主密封失效时，辅助密封腔内压力上升，驱动备用密封的两端面立即贴合进入工作状态，起到二次密封的作用，阻止危险介质向大气泄漏保证主机连续运转，此系统比传统的双端面密封及串联密封的结构简单，安装方便，给出了非接触式备用机械密封的     

机械密封的失效模式与临界平衡比的计算

介绍了与机械密封面积比有关的几种主要失效模式，如密封面开启失效，早期磨损，干运转，疱疤，相态失稳，倾斜失稳，液膜失稳，液膜破裂，汽化和丧失密封性等，并提出考虑主要失效现象的临界平衡比公式，根据临界面积比的大小，要以判断所选用的机械密封平衡比是否合理，并进一步来确定该机械密封的合适面积比。给出了计算实例，计算结果可供机械密封设计时选用。     

CCUS地质封存下水泥环密封完整性失效机理及控制措施

CO₂封存过程中,水泥环作为套管-水泥环-地层组合体中最薄弱的环节,在压力变化尤其是交变压力的作用下,水泥环密封完整性失效的风险极大,其完整性失效容易导致CO₂从环空中泄露至地表,严重影响CO₂的封存。基于已建立的水泥环组合体弹塑性模型,利用MATLAB进行模拟分析,研究了全井段水泥环密封完整性失效机理以及相应的控制措施。研究结果表明,水泥环密封完整性失效主要与水泥环进入塑性产生的塑性应变累积有关,并且无论是在浅层段还是深层段,只要水泥环进入塑性,在多次交变压力的作用下,就有产生“界面应力反转”的风险,导致水泥环密封完整性的失效。要想避免水泥环密封完整性的失效,应首先避免水泥环进入塑性状态,即提高水泥环屈服内压；浅层段,低弹性模量的水泥环可增加水泥环屈服内压；深层段,在水泥环泊松比“临界点”之上,降低水泥环弹性模量可有效提高水泥环屈服内压,在水泥环泊松比“临界点”之下,增加水泥环弹性模量可提高水泥环屈服内压。当由于套管压力过大,水泥环不得不进入塑性状态时,低弹性模量和高泊松比的水泥环可以降低卸载后的水泥环残余应力,延缓“界面应力反转”现象的发生。     

高压分离器双锥环密封失效的数值模拟

针对国内某厂一台双锥环密封的高压分离器在非正常操作中出现的泄漏失效,采用ＰＡＦＥＣ大型有限元程序进行了模拟全操作过程的ＦＥＭ分析。在按实际建立的力学与传热计算模型上,数值模拟了包括预热、正常操作和急冷等工况下典型节点的温度－时间变化,垫片应力－介质内压变化的关系,同时探讨了双锥环内侧与端盖圆柱面之间的间隙与密封性能的关系。计算结果表明,双锥环密封结构的温度改变导致垫片应力的改变是密封失效的重要原因     

油田大功率注水柱塞泵柱塞密封的设计研究

对大功率油田注水柱塞泵柱塞密封的失效机理进行了论述,分析了现有几种典型的密封结构.在此基础上,设计了一种新型高压柱塞密封装置.其主要特点是:组合使用几种不同材料,采用合理的反向加载方式,使用了特殊结构的异向套和优质隔环等.     

羰基合成高速离心压缩机干气密封的研制与应用

干气密封由旋转环、静环、弹簧、密封圈以及弹簧座和轴套组成。干气密封旋转环密封面经过研磨、抛光处理，并在其上面加工出有特殊作用的流体动压槽。干气密封旋转环旋转时，密封气体被吸入动压槽内，由外径朝向中心，径向分量朝着密封堰流动。由于密封堰的节流作用，引入密封面的气体被压缩，气体压力升高。在该压力作用下，密封面被推开，流动的气体在两个密封面间形成一层很薄的气膜，该气膜实现密封作用。     

机械密封的失效模式与临界平衡比的计算

介绍了与机械密封面积比（平衡比）有关的几种主要失效模式，如密封面开启失效、早期磨损、干运转、热裂、疱疤、相态失稳、倾斜失稳、液膜失稳、液膜破裂、汽化和丧失密封性等，并提出了考虑主要失效现象的临界平衡比公式。根据临界面积比的大小，可以判断所选用的机械密封平衡比是否合理；并进一步来确定该机械密封的合适面积比，给出了计算实例，计算结果可供机械密封设计时选用。     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

正~~     

An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.