降膜蒸发多效回热型太阳能海水淡化装置的测试与分析

对利用太阳能驱动的横管降膜蒸发多效回热型海水淡化装置进行了实际天气条件下的动态测试.对影响产水率的主要因素作了探索与分析,给出了合理的取值范围.实验结果证明,由于采用了多效回热以及其他强化系统产水性能的措施,使系统的产水效率比传统的盘式太阳能蒸馏器提高了近2.5倍.     

负压多级降膜蒸发在太阳能海水淡化中的应用研究

深入分析了海水在水平管外蒸发以及饱和水蒸气在水平管内冷凝的机理。分析表明：采用负压多级降膜蒸发，在加热水温度一定的情况下可大大强化传热传质过程，提高海水的蒸发量；利用饱和水蒸气在水平管内加压冷凝，可有效地促进热质交换过程，提高冷凝的效果。在该理论指导下设计制造的具有闪蒸与压缩蒸馏性能的太阳能海水淡化装置，不仅比传统的盘式太阳能淡化装置效率提高很多，而且可利用较低温度的太阳能加热水进行海水淡化，淡化效率保持在70％以上。     

一种新型多效内回热式太阳能海水淡化装置

设计建造了一台具有三效回热性能的紧凑式小型太阳能海水淡化装置,在稳态和实际天气条件下对装置的性能进行了测试.该装置的蒸馏系统采用了多级降膜蒸发及降膜凝结技术,使其中大部分蒸气潜热及部分盐水的显热得到了多次重复利用.实验测试表明,当系统在稳态温度70～75 ℃附近运行时,其性能系数可达2.0左右,在晴朗天气下,实际每平方米太阳能集热器的产水量可达10 kg.     

双塔竖直蒸发管高温多效蒸发海水淡化实验系统

低温核供热堆与高温竖直蒸发管多效蒸发(VTE-MED)耦合的方案,是国际原子能机构推荐的核能海水淡化优选方案之一。在清华大学核能技术设计研究院建立了双塔VTE-MED实验系统,其最高设计咸水温度为120℃,原料海水循环流量为3300kg/h,3效的产水量约180kg/h。该文介绍了海水蒸发器、预热器、终端冷凝器、海水箱等系统主要设备及海水淡化蒸发工艺流程。针对实验系统的运行稳定性实验研究,表明这一实验系统已能建立起稳定的工作状态,可利用该系统在真实流动参数下,进行诸如多孔孔板节流特性关键技术的热态实验研究及蒸发工艺流程等实验研究。     

LiBr溶液高温竖管降膜吸收过程的实验研究

针对吸收式太阳能海水淡化系统,设计了一套竖管降膜吸收实验装置,以溴化锂溶液为工质对装置进行了实验研究.通过改变水和溶液温度、喷淋量及溶液的浓度,测试了不同工况下系统的运行情况,得出溶液具有较好吸收率的基本条件,给出了系统最佳运行的参数范围.实验表明,在运行压力达到10 kPa和溶液浓度为50%左右的情况下,当被吸收水的温度高于30℃时,溶液已有较好的吸收速率,此时热源的温度仅为45℃～55℃,这十分有利于太阳能集热系统发挥供热效率.     

三维光热材料的制备及其太阳能脱盐性能

光热多孔材料是太阳能海水淡化应用的关键所在,受生物质天然多孔互联结构的启发,通过冷冻干燥和高温碳化工艺制备具有三维互联孔道结构的生物质碳基蒸发器,研究其微结构特征、水输送和蒸发性能以及三维结构对材料蒸发性能的增强作用。结果表明：该蒸发器具有高度互联的孔道结构和高达95.5%太阳光吸收率,在太阳光下实现了1.71 kg/(m²·h)的蒸发速率和89%的光热转换效率,可以有效蒸发和淡化海水。此外,在三维结构特征下,实现了高达2.65 kg/(m²·h)的蒸发速率,三维结构有效提升了材料的蒸发性能,显示了优异的太阳能蒸发/脱盐效果。     

管式太阳能海水淡化装置的实验研究

针对淡水资源短缺的问题,设计制作了一种利用太阳能或者其他余热驱动的管式海水淡化装置.通过对装置的每小时产水量及装置内各测点温度进行测试,对装置的性能进行了定功率和定温度供热的实验研究.定功率实验结果表明,实验装置的性能系数最高能达到1.5左右;装置的产水量达到了20.078 kg/(m2.d),相比传统装置有很大的提高.定温加热的实验结果表明,运行温度的增加可以提高装置的产水量.在相同实验条件下,多级装置相比单级装置能获得更高的产水量.     

太阳能海水淡化蒸馏器的传热实验研究

利用科研项目设计制造的太阳能海水淡化装置进行实验教学,由学生完成太阳能热水系统的测试,海水淡化蒸馏系统的运行,并进行实验数据整理和分析,得出实验结论.     

水平管外海水降膜蒸发传热特殊现象分析

以低温多效蒸发海水淡化装置中的水平管降膜蒸发过程为研究对象,对海水水平管降膜蒸发的传热系数在不同蒸发温度、雷诺数(Re)等条件下沿圆周角方向的分布特征进行了实验研究.研究结果表明:海水作为实验流体时,传热系数随蒸发温度的升高而降低,随Re的增大而呈现先升高,达到最大值后略微降低的趋势,随圆周角的增大而先减小后增大.     

聚能式多效太阳能海水淡化系统性能研究

提出了一种聚能式多效太阳能海水淡化系统,利用太阳能加热海水至蒸发沸腾以达到淡化海水的目的,同时采用多效结构,利用了蒸汽凝结时的冷凝潜热,提高能量利用效率.在典型冬季晴朗天气条件下运行,系统全天淡水产量为10.79 L,集热效率最高达到35％.     

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).     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

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.