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1.
通风模式对室内环境品质及建筑运行能耗均有重要影响。文章在采用非稳定传热方法得到建筑围护结构热边界条件的基础上,对比研究了寒冷地区某办公室分别采用置换通风和层式通风的通风效果和节能特性。结果表明:在保证舒适性的前提下,研究对象采用置换通风的送风温度范围为13.0~27.0℃,采用层式通风的送风温度范围为19.0~24.0℃。采用实时调整送风温度的措施可以使置换通风中处理送风的机械制冷量日平均节约率达到2.87%,使层式通风中处理送风的机械制冷量日平均节约率达到5.16%,与基准送风温度对应的送风量相比,两种通风模式下的送风量均有所下降,其风量节约率可分别达到22.65%和32.14%。置换通风的室内温度更接近舒适,两种通风模式下室内污染物浓度均未超标。  相似文献   

2.
目的研究夏季办公室置换通风、侧送风和混合通风的特点及效果,探索不同通风方式对室内空气品质和热环境的影响,设计有效的办公室通风系统,创造良好的室内环境.方法利用Airpak软件对置换通风和侧送风进行模拟计算,得出了两种送风方式下室内温度场、速度场以及PMV-PPD指标分布.结果侧送风形式下,空调送风运动轨迹呈抛物线分布,新风抛物线以下工作区域温度较低,主要分布在24~28℃,在人体经常活动的范围内速度大小为0.25 m/s,PMV-PPD指标接近于0.置换通风热力分层,温度自下而上升高,工作区内风速为0.096 m/s,温度为26℃,PMV-PPD指标小于侧送风形式的PMV-PPD指标.混合通风工作区温度分布比较均匀,为28℃左右,但是工作区风速较高,为0.6 m/s.结论办公室采用置换通风方式活动区空气品质好,既能营造良好的工作环境又可利用空气自身浮升力达到节能目的,是一种理想的通风方式.  相似文献   

3.
置换通风在纺织厂应用的探讨   总被引:7,自引:0,他引:7  
从置换通风的基本理论和纺织厂空气调节的具体情况出发,借助CFD手段,研究了采用置换通风时纺织厂各车间的送风量的确定,能源消耗,气流组织,温度分布以及空气品质等问题,结果表明,大多数车间在应用置换通风系统后有较为明显的节能效果,且在空气品质方面也具有一定的优势。  相似文献   

4.
以两开口单区建筑为研究对象,采用理论分析方法,推导出风机与热压共同驱动的复合置换通风的非稳态数学模型。研究了机械风量、两开口面积比和无量纲特征时间对室内热分层高度和自然通风量的影响。研究结果表明:在复合置换通风中,增大机械风量使热分层高度增大而自然通风量减小。无量纲特征时间增大,使热压主导通风模式存在所对应的机械风量的上限值减小。对于机械送风,开口面积比增大引起热分层高度和自然通风量随机械风量的变化率增加,热压主导模式存在所对应的机械风量的上限值增大,而对于机械排风,情况相反。当两开口面积相等时,采用机械送风和机械排风的效果是一样的。  相似文献   

5.
比较了混合通风、置换通风、地板送风和碰撞射流通风这4种送风方式的特点,利用试验方法实测了这4种方式下空调房间的室内温度、气流速度和CO2质量浓度分布,讨论了室内热环境特点的异同,对比分析了4种送风方式下室内热舒适性、污染物分布特征,并对送风能量利用情况做了估计.  相似文献   

6.
以低冷负荷住宅建筑为研究对象,采用计算流体动力学(CFD)方法,研究送风末端与冷吊顶结合时,最小新风量的有效利用,通过数值模拟得出了上送风、置换通风、下送风三种气流组织形式与冷吊顶相结合时室内各位置的风速、温度、相对湿度、污染物浓度等参数,对三种气流组织下的室内空气质量水平和热舒适水平进行了综合评价.研究结果表明,与冷吊顶结合时,采用置换通风和下送风形式,室内可获得更佳的室内空气品质,最小新风量可获得更有效的利用.  相似文献   

7.
为了研究大空间建筑在分层空调环境下的室内空气垂直温度分布特性及其影响因素,该文对某大空间建筑在夏季工况不同喷口送风下的室内温度进行了试验测试。通过对喷口高度、送风量、室外综合温度等参数的分析,获得了室内空气垂直和水平温度场分布特性。研究结果表明,喷口高度和送风量的增加会引起温度分层面升高和垂直温度分布不均匀,且导致较大的对流转移热负荷,但水平温度分布趋于均匀;室外综合温度与非空调区的温度及梯度密切相关。该文研究结果可为喷口送风的气流组织设计提供参考。  相似文献   

8.
地板送风室内温度不均匀分布特性的实验研究   总被引:1,自引:0,他引:1  
通过变化送风参数和室内热源,对6种典型工况的实验结果进行了分析,得到了地板送风室内温度分布的一些特性.针对地板送风室内温度分布的不均匀性,采用工作区垂直温差和0.1m高度处的空气温度与送风温度之差来表征工作区温度分布.实验结果表明:单位送风量的室内热源散热越大,不仅室内垂直温度梯度较大,而且工作区垂直温差增加的幅度比送回风温差增加的幅度更大,当室内冷负荷从324W逐渐增大到468W时,工作区垂直温差与其送回风温差之比从0.468增大到0.573;室内工作区垂直温度分布的形状与室内热源分布情况有关,当热源位于吊顶上时,工作区上下垂直温度梯度较大,中间垂直温度梯度较小;当送风温度提高5.7℃时;工作区垂直温差减小70%;工作区0.1m高度处的空气温度与送风温度之差约占送回风温差的50%.  相似文献   

9.
针对装配式建筑特殊结构形式对暖通空调(heating,ventilating and air conditioning,HVAC)系统新的挑战与机遇,结合置换通风优势以及装配式住宅建筑墙体空间结构特征,开展了装配式住宅侧墙通风系统集成研究.采用数值建模研究手段,基于计算流体力学(computational fluid dynamics,CFD)计算平台,在诠释系统架构与运行方式基础上,重点分析了该新型系统运行效果表征关键环节,即室内气流组织效果.选择了夏季室内三种不同送风模式以及传统射流送风方式进行对比分析,并以风速不均匀系数、空气扩散性能指标以及通风效率等作为系统性能评价指标.研究结果表明:在相同的制冷量限定条件下,大面积侧墙下送上回和中送风工况的风速不均匀系数、空气扩散性能指标、通风效率分别为0.432、0.963、1.279和0.386、0.926、1.574,优于传统射流送风方式的0.552、0.483、1.081.尤其采用中送风模式下,室内工作区内温度较低,在满足室内设计温度的条件下具有节能潜力.该装配式住宅侧墙送风系统,不仅可提高室内热舒适性,而且能一定程度上降低建筑能耗,为装配式建筑与暖通系统的融合与一体化设计开拓了新思路.  相似文献   

10.
影剧院建筑内置换通风方式的优化设计   总被引:1,自引:0,他引:1       下载免费PDF全文
为了更好地研究置换通风方式在影剧院建筑内的应用,采用CFD方法,对影剧院内采用地面附近侧送风形式的置换通风进行了数值模拟.计算结果显示,CFD技术能够较好地应用在影剧院建筑内置换通风方式的优化设计方面,并能够得出比较合理的设计参数.在原有设计的基础上,通过合理地调整风口位置及送风参数获得了较好的通风效果.把CFD技术引入到对影剧院建筑内空调系统气流组织方案的设计中,有利于地面附近侧送风方式的应用,也有助于节能措施的推广与实施.  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.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

14.
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   

15.
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   

16.
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   

17.
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   

18.
19.
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   

20.
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  相似文献   

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