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1.
无泵溴化锂吸收式制冷机二次发生器的实验研究   总被引:3,自引:0,他引:3  
在太阳能无泵溴化锂吸收式制冷系统降膜吸收器、降膜蒸发器、弦月形热虹吸提升管、冷凝器等主要部件的基础上,设计了一套二次发生器,有效地降低了热源温度(最低启动温度为68℃,稳定运行温度范围为80-93℃),提高了太阳能的利用率.二次发生器在提高系统冷凝器与蒸发器间压差的同时,使系统能在较低的溶液初始质量分数范围(46%~54%)下运行,放气范围可达6%,吸收率是二次发生器关闭时的3倍,有助于提高吸收器性能;冷剂水产量提高,是相应未开二次发生装置时冷剂水产量的1.68倍,蒸发效果明显改善;随着加热水温度和吸收器浓溶液温度的升高,吸收器冷却水温差和冷媒水温差均增大,冷媒水出口温度降低,改善了制冷系统的整体运行性能,平均制冷系数可达0.725.  相似文献   

2.
根据系统各单元对压力的需求以及系统设计参数与流型参数之间的内在关系,对小型太阳能无泵溴化锂(LiBr)吸收式制冷机中受全程加热的溶液提升管所需的最低高度进行了理论计算,给出了算例.计算结果说明,对溶液提升管高度提出要求的主要是稀溶液的设定浸没高度和吸收器的设计高度,分别占总高度要求的50%和25%左右.在提升管中为弹状流的形态下,所需溶液提升管的高度可以比传统装置的设计高度降低20%。  相似文献   

3.
太阳能混合吸收式制冷空调系统的性能研究   总被引:3,自引:0,他引:3  
提出了一种新型太阳能混合吸收式制冷空调系统,可以较好地利用太阳能制冷,克服传统吸收式系统在利用太阳能实现制冷时存在整体效率低的弊端.混合吸收式制冷循环增设附加高压发生器,同时使高压发生器再生出LiBr溶液与低压吸收器的吸收后的溶液混合,进入高压吸收器,提高了高压吸收器中LiBr溶液的浓度使其压力降低.研究结果表明,新型制冷循环的制冷系数高达0.61,驱动热源的可利用温差最高可达33.2℃,新型太阳能混合吸收式空调系统的整体效率比两级吸收式太阳能空调系统有较大提高,最大提高幅度为94.5%,能更好地发挥太阳能空调的优势.  相似文献   

4.
提出了一种新型高效太阳能LiBr吸收式制冷循环.在传统的两级吸收式循环的基础上,将高压发生器发生出的LiBr溶液与低压吸收器吸收后的溶液混合,在发生温度与压力允许的范围内,使高压吸收器的吸收剂浓度较两级吸收式循环高,从而在相同的冷凝条件下减小了其压力.分析了新型循环的性能,并与传统的两级吸收式制冷循环进行比较,结果表明影响系统性能的主要因素是溶液浓度及低压发生器压力,新型吸收式循环的发生热源温度在75~85℃,系统的热力系数最高可达0.605,其热源可利用温差最大可达33.5℃,其性能在传统循环基础上有较大提高,效果较明显.  相似文献   

5.
依据溴化锂溶液的热力学性质和热力学第二定律,对具有一种新的溶液循环的双吸收式热变换器的热力过程进行了炯分析.结果表明:与普通循环相比,新的溶液循环不仅具有更高的性能系数和炯效率,而且吸收蒸发器具有更宽的操作范围.当热源温度、冷凝温度和吸收器的温度分别为70、25和150℃时,普通循环的炯效率是56.2%,而新循环的炯效率是65.7%.当在吸收蒸发器和再生器之问增加第二溶液热交换器时,新循环的炯效率可以达到69.6%,而且吸收蒸发器的操作范围进一步增加.同时也讨论了其他操作参数对系统炯效率的影响.  相似文献   

6.
为了降低汽车液压动力转向系统中存在的较大能量损失,整个转向系统要消耗原动机约3%的能源,但真正转向消耗的能量只占其中不到40%的问题,提出了一种含有浮动块的新型汽车转向泵。同时研究新型转向叶片泵变量机构的动力学特性,分别建立了变量机构的动力学和叶片泵流量模型,并对泵在液压转向系统向系统执行机构的输出流量进行仿真. 结果表明该泵能有效降低转向系统的能量损失,是一种较有应用前景的新型叶片式转向泵.  相似文献   

7.
对船坞泵站泵装置进行了模型试验,讨论了水泵参数换算、试验结果及误差分析等问题,研究了导流方案与悬空高度对泵装置性能的影响.为提高泵装置性能,将原出水管道虹吸下降段及出口管径设计成渐扩管.试验结果表明,在悬空高度hp=0.76D0时,各种工况下进水流态平顺,流道内无涡带发生,水泵运行平稳,装置效率可提高0.5%-1.5%.  相似文献   

8.
为避免CO2跨临界循环运行因高低压差增大而导致压缩过程偏离等熵过程太远,减小CO2跨临界循环系统损失,提高系统性能并降低系统成本,采用带节能器的CO2跨临界制冷循环,对其热力学模型进行计算分析,并与基本带膨胀机循环进行对比.结果表明,不同于传统工质带节能器制冷循环的补气压力介于系统高压和低压之间,带节能器CO2跨临界制冷循环的补气压力应介于临界压力和低压之间;其制冷系数与膨胀机效率为0.6的系统性能相当;制冷性能随蒸发温度的升高而提升,随气体冷却器出口温度的升高而降低;相对补气压力对系统性能的影响较大,当相对补气压力为0.9~1.1时制冷性能较高,在较低蒸发温度下降低压缩机排气温度的优势明显.  相似文献   

9.
LiCl水溶液垂直降膜吸收过程的实验与模拟   总被引:3,自引:0,他引:3  
文中介绍了以空气除湿为目的的LiCl水溶液的吸收实验和模拟工作。建立了垂直结构的吸收器实验系统;研究了LiCl水溶液与空气的液气体积流量比和溶液初始浓度对垂直降膜结构吸收器性能的影响;发现垂直降膜结构的吸收器优于鲍尔环填料结构的吸收器。实验与一维稳定分子扩散原理的模拟结果表明,在实验的操作条件下,该装置可以使空气的相对湿度下降6%~35%。  相似文献   

10.
为研究水平管束式吸收器二元溶液两相流动传热传质规律及部件仿真与可视化方法,将水平管束式吸收器降膜吸收过程分为3个区域,即沿管壁的降膜吸收区、管底部的液滴形成区以及管与管之间的液滴降落区,应用Matlab ODE45求解器仿真求解,并将仿真结果可视化,得到了水平管上溶液温度、浓度、质量流量以及冷却水温度的变化规律,分析了不同溶液质量流量、蒸发温度对吸收器和蒸发器性能的影响.结果表明:每根水平管上的溶液温度都会有一个先降后增的过程,以第1根水平管为例,溶液质量流量为0.024kg/ms,蒸发温度为12℃,润湿率WR=0.8时,经过降膜区后温度从56℃下降到47.5℃.经过液滴形成区以后.温度又从47.5℃升至51.5℃.不同蒸发温度工况下的制冷量仿真结果表明,实际运行条件下润湿率维持在WR=0.6-0.8之间.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
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.  相似文献   

13.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
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。  相似文献   

18.
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.  相似文献   

19.
20.
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  相似文献   

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