太阳辐射对南方多层墙体热湿性能影响的研究

本文以空气含湿量和温度为驱动势建立模型对南方地区典型多层墙体进行了动态模拟。在主模型中,将太阳辐射总热量分解,得到了建筑不同朝向外墙的太阳辐射得热量,进而分析了在太阳辐射影响下墙体的热湿性能;在子模型中,不考虑太阳辐射得热对墙体热湿性能的影响。将模拟结果同实验测试数据进行对比后可知,太阳辐射得热对多层墙体外层的温度影响较明显,而墙体温度的升高会造成墙体内空气含湿量的增大。     

内置保温系统在严寒寒冷地区被动式超低能耗建筑的模拟研究

采用Flixo软件对内置保温系统层间结构受力挑板热桥部位进行模拟研究,得出挑板外侧无保温、挑板外侧粘贴不同保温材料及上下延伸不同尺寸、挑板厚度不同等构造做法下的线性热桥值和内表面温度,及其变化规律;采用DeST软件针对被动式超低能耗建筑能效指标模拟得到能耗计算时较合适的外墙传热系数限值,进而反推得到内置保温系统用于严寒寒冷地区被动式超低能耗建筑中的可行性方案.     

EPS外墙外保温系统的温度场与温度应力研究

基于有限单元法,建立了考虑太阳辐射和大气温度变化的EPS外墙外保温系统的温度效应有限元模型。以东北大庆地区某住宅建筑为例,对带有窗洞外墙外保温墙体的温度效应进行了研究。结果表明:保温墙面层和基层墙体内温度沿墙厚均基本呈均匀分布,保温层内部温度基本呈线性分布,且变化幅度约等于墙体的内外表面温差;夏季和冬季墙体内外表面温差分别可达-30.5℃和48.8℃;温度作用下,窗洞四角部位的面层极易发生斜向裂缝,上下部位的面层易发生竖向裂缝,左右部位的面层易发生水平向裂缝;为避免保温墙面层收缩引起裂缝,应尽量避免在夏季进行保温墙面层施工。     

双层定型相变围护结构夏季热特性实验研究

以石蜡作为相变材料(Phase Change Material,PCM),高密度聚乙烯作为支撑材料,膨胀石墨作为导热增强剂,制成定型相变板。将制备的相变材料板以"三明治"形式贴于轻质实验房南墙内外侧,实验房内侧相变板相变温度约为17～26℃,在冬季发挥保温作用;外侧相变板相变温度约为26～36℃,在夏季发挥隔热作用。对其在夏热冬冷典型城市武汉地区应用的热特性进行实验研究,结果表明,定型相变材料板状态稳定、性能优良。夏季外侧相变墙发挥作用,能够很好地吸收太阳辐射的热量,降低并延缓室内温度峰值,可降低建筑冷负荷,提高室内环境热舒适性。     

多孔盖板型太阳能平板空气集热器热性能模拟

建立多孔盖板型太阳能平板空气集热器的数值计算模型,利用已有实验数据验证模型的准确性。基于该数值模型研究单位面积系统风量、太阳辐射照度和集热层吸收率对集热器热性能的影响。结果表明,多孔盖板型太阳能平板空气集热器的热性能较普通平板集热器有明显改善。系统风量增大,集热效率相应地增大,而空气通过集热器的压力降也会迅速增大,从而造成系统风机耗电量增加,所以应综合考虑系统的热性能和风机耗电量,合理选择系统风量。空气温升随太阳辐射照度增大而升高,并且接近线性增长,集热效率随着辐射照度增大呈缓慢下降趋势。集热效率随着集热层吸收率增大而显著增大,且接近线性增长。     

被动式太阳能建筑中特朗伯墙体的研究综述

Trombe wall(特朗伯墙)是被动式太阳能建筑集热蓄热的围护结构,能够充分利用太阳能降低建筑能耗,因此受到了广泛关注。本文从理论计算、运行性能研究、CFD模拟研究、评估指标四大方面综述了近20年来与特朗伯墙相关论文的研究成果。总结了影响特朗伯墙系统运行性能的三大因素:材料(集热罩材质、墙体材质)、墙体尺寸参数(集热墙体厚度、空气层宽度、特朗伯墙体与整个南墙墙体面积之比)、建筑所在室外环境即气候特征(太阳辐射强度、室外风向风速);提出了利用CFD模拟研究时边界条件设定的注意事项。通过具体可行的结论为建筑师或相关工程设计人员在特朗伯墙设计阶段提供技术参考。     

软索连接装配式混凝土圆孔墙抗震性能试验研究#br#

为研究软索连接装配式圆孔剪力墙的抗震性能,分析翼墙对主墙的影响,设计一字形、L形、工字Ⅰ形和工字Ⅱ形4类共8个足尺装配式圆孔剪力墙试件,进行拟静力试验,通过对试验现象和数据进行分析,研究构件的破坏形态、特征荷载、变形性能、受剪承载力等特性。结果表明：采用软索连接的翼墙能有效提高主墙的抗裂性能,有效避免主墙沿圆孔的竖向裂缝,同时能改变主墙的应力分布和破坏形态;翼墙能够有效提高主墙的屈服荷载和极限荷载,但对屈服位移、延性的影响不明显;墙体弹性层间位移角能够满足我国规范中对剪力墙的要求,弹塑性层间位移角较小,宜提高软索锚固设计;墙体中的圆孔会大大降低墙体的受剪承载力;通过规范公式对该类型墙体进行受剪承载力计算,发现多数墙体的计算值远大于试验值,基于试验结果,建议将规范公式进行05倍折减后,再用于该类型墙体的受剪计算。     

被动式太阳能集热蓄热墙对室内湿环境调节作用的研究

长期以来,关于被动式采暖降温技术的研究,主要集中在不同结构、材料等对室内热环境影响的分析评价方面,而关于被动式集热蓄热墙体对室内湿环境调节作用的性能研究很少.由于外围护结构的结露现象影响建筑的寿命、室内空气品质和人体舒适性而被人们广泛关注.为了解决结露的问题,通常采用的方法是加强外围护结构的绝热保温性能或适时地进行通风换气.在我国寒冷地区,随着建筑节能相关的规范标准的颁布实施,外墙的结露问题得到了较好的解决,但外窗的结露现象依然普遍存在.本研究在两间分别采用被动式集热蓄热墙体和普通保温节能墙体的同实体大的实验房屋中,利用多点温湿度及风速的计算机巡回监测系统等,对室内外温湿度、风速、太阳辐射强度及墙体内温度等参数在采暖期进行了长期实测,并通过对大量测试数据的分析,对被动式太阳能集热蓄热墙体对室内湿环境的调节作用进行了深入地实验研究,同时对由于采用集热蓄热墙体所带来的湿环境的明显改善进行了机理分析.     

软索连接装配式混凝土圆孔墙抗震性能试验研究

为研究软索连接装配式圆孔剪力墙的抗震性能,分析翼墙对主墙的影响,设计一字形、L形、工字Ⅰ形和工字Ⅱ形4类共8个足尺装配式圆孔剪力墙试件,进行拟静力试验,通过对试验现象和数据进行分析,研究构件的破坏形态、特征荷载、变形性能、受剪承载力等特性。结果表明:采用软索连接的翼墙能有效提高主墙的抗裂性能,有效避免主墙沿圆孔的竖向裂缝,同时能改变主墙的应力分布和破坏形态;翼墙能够有效提高主墙的屈服荷载和极限荷载,但对屈服位移、延性的影响不明显;墙体弹性层间位移角能够满足我国规范中对剪力墙的要求,弹塑性层间位移角较小,宜提高软索锚固设计;墙体中的圆孔会大大降低墙体的受剪承载力;通过规范公式对该类型墙体进行受剪承载力计算,发现多数墙体的计算值远大于试验值,基于试验结果,建议将规范公式进行0.5倍折减后,再用于该类型墙体的受剪计算。     

严寒地区太阳能通风墙的热性能试验研究

以太阳能通风墙为研究对象,利用已建成的1∶1实体模型,针对不同构造的集热板、集热罩和热传输方式对太阳能通风墙热性能的影响进行了试验研究。试验结果表明,集热墙与地下蓄热式通风口同时开启的工况下,白天室内平均温度提高了7.6℃,夜间提高了1.8℃,且温度下降速率缓慢,有效地抑制了室温的波动;单框双玻塑钢集热罩腔体内温度白天的峰值为62.3℃,在20:00室外温度为6.1℃的情况下仍能达到16.5℃左右,比Ⅰ型高1.8℃,阻止了腔体热量损失的减少,提高了建筑的热稳定性;蓝膜集热板白天的集热效率比普通集热板高3%左右,夜间的保温性能更是比其高出了一倍。     

新建节能建筑墙体材料层及排布对干燥过程的影响

建筑围护结构内的热湿耦合传递是一个非常复杂的过程,其研究是降低建筑能耗、评估和预防湿害、提高室内热舒适性、室内卫生及优化围护结构性能的基础。新建节能建筑墙体具有初始含湿量大的特点,若墙体湿积累过大,则容易出现墙体表面剥蚀、渗漏、发霉甚至结构出现损坏的现象。墙体干燥时,传热传质过程同时发生且相互耦合。目前相关热物性仿真软件、理论研究和设计规范主要建立在热传递的基础上,忽略了湿传递的影响,对新建建筑墙体干燥不适用。WUFI~? Pro热湿仿真软件充分考虑了材料本身含湿量、风驱雨、太阳辐射、长波辐射、毛细传输和夏季结露等典型气候的影响,实现了对自然气候条件下建筑构件非稳态热湿性能的真实计算。节能墙体多在外墙添加内外保温层来增加围护结构的传热热阻,且在保温层内外两侧分别添加隔汽层和空气层的措施来防止保温层受潮,最终提高围护结构的保温性能。为墙体美观,多在围护结构的内外两侧分别黏贴墙纸和釉面砖。采用WUFI~? Pro对北京地区2种典型的建筑墙体进行热湿耦合传递模拟,分析新建建筑墙体在不同保温层材料和位置时的干燥过程,以及保温层两侧的隔汽层和空气层、墙体两侧的墙纸和釉面砖对墙体干燥过程的影响。模拟用室外条件为北京典型气象年小时室外气象参数,室内条件设定室内冬季供暖温度T_1=20℃,夏季室内温度设计值T_2=25℃,全年平均相对湿度为50%。模拟外围护结构属于西向,墙体温湿度初始条件为:相对湿度为100%,温度为15℃。模拟结果表明:内保温层的设置非常不利于围护结构的干燥,容易在内保温层和砌块之形成湿积累,降低围护结构的耐久性;EPS、PU和XPS都能降低围护结构含湿量,但EPS更有利于墙体干燥;隔汽层和空气层的添加可一定程度上阻止保温层受潮,避免造成湿积累,进而提高围护结构的保温性能;釉面砖和墙纸的黏贴将严重延缓围护结构的干燥过程,降低围护结构的保温性能,缩减建筑构件的使用寿命。     

A simple procedure for selection and sizing of indirect passive solar heating systems

Equivalent sol-air temperatures have been defined for four indirect gain passive solar heating concepts, namely, mass wall, water wall, Trombe wall and solarium. Steady state thermal efficiencies have also been defined as a measure of the ability of each system to deliver heat into the living space.

Design curves have been developed which relate the average instantaneous solar radiation incident on the passive element to thermal efficiency for different values of ambient temperature. These curves are useful in selection of an appropriate passive heating concept for a particular location.

It is inferred that a solarium is most effective at very low levels of incident radiation and low ambient temperature. Water walls and Trombe walls are most efficient at higher levels of incident radiation.

A simple procedure has been developed for a first approximation of sizing the selected system using these design curves and a minimum of meteorological information, namely, monthly average of daily global solar radiation, monthly average maximum and minimum ambient temperatures.     

垂直绿化改善建筑室内、外热环境效果分析

垂直绿化已成为一种节省空间的节能措施。为研究夏热冬暖地区垂直绿化改善室内热环境和周围热环境的效果,对用爬山虎绿化的建筑的内外壁温及建筑周围室外温度进行实测分析;并用CFD模拟了有、无绿化房间的辐射温度,室内空气温度,PMV、PPD热舒适性指标进行对比分析。测试结果表明,垂直绿化建筑周围热岛效应仅为0.9℃;不同朝向的有绿化墙壁比没绿化的壁面温度有不同程度的降低。效果最好的外壁温平均降低了6.8℃,内壁温平均降低了1.72℃。CFD模拟结果显示,绿化后房间空气温度和辐射温度的平均值分别降低了0.4℃和1℃;PMV-PPD也有改善,而且舒适指标的最大值也减小了。分析可得垂直绿化是一种绿色有效、主动的隔热节能方式。     

Solar heating and night radiation cooling by a Roof Radiation Trap

The paper describes a new system, the Roof Radiation Trap, which utilizes solar energy for heating of buildings in winter and nocturnal radiation for cooling in summer. The radiation trap consists of fixed insulating layer separated from the flat roof and glazing, protected by hinged insulating panel, in the southern gap between the roof and the fixed insulation. This fixed insulating layer is covered by corrugated metal sheets, painted white, which serve as nocturnal radiators in summer.The radiation trap is integrated with the building, thermally as well as architecturally. In winter the sun energy penetrates through the glazing and is absorbed directly in the roof, which serves as a combined collector, storage for one night and heat distribution system.The hot air in the space between the flat roof and the fixed insulation is blown into a thermal storage of gravel, under the floor or inside the building. The stored heat is “recovered” by forced convection during cloudy days.In summer the penetration of solar radiation during daytime is prevented by the hinged insulating panel. At night the painted external metal layer is cooled by outgoing radiation and the air under the corrugations is blown into the space of the radiation trap and cools the roof, which, in turn, serves as a heat sink during the next day. Nocturnal evaporative cooling can supplement the radiant cooling.     

Heat transfer modelling on windows and glazing under the exposure of solar radiation

Due to the effect of solar radiation on windows and glazing system the evaluation of heat flow is of primary importance in modeling the thermal performance within building interiors to account thermal comfort and overall energy consumption of a building. In this context the optical properties of window glazing are measured to determine the percentage absorption of incident solar radiation. An experimental study was performed in a room to measure the glazing surface temperature due to the global radiation on it. The corresponding window plane global radiation and horizontal global radiation were measured outside for simulation. Mathematical models have been developed to simulate the window plane solar radiation and corresponding glazing surface temperature aiming at validating the measured values. The thermal model is concerned with laminar heat transfer for natural and forced convection process according to the ambient conditions. The estimated errors between experimental and simulated values of window plane radiation and glazing temperature are shown to be within ±5%. Using the developed thermal model the heat flow inside the room through windows is determined. Thus overall heat transfer coefficient of glazing (U-factor) and the Solar Heat Gain (SHG) of building interior have been predicted from the simulation.     

考虑太阳辐射的保温墙体温度场温度应力及其计算软件

考虑太阳辐射建筑外墙温度场及温度应力的计算是进行保温墙体设计、研究的基础。以热传导理论为基础,建立了保温墙体变温环境下的时时温度场、温度应力计算模型。在此模型基础上,编制了保温墙体温度场、温度应力计算软件。软件可实现典型保温墙体及用户自行设计的保温墙体在给定环境条件下墙体内各功能层温度场、温度应力的时时计算。     

特朗贝墙体冬季集热性能的计算及预测

特朗贝墙体的集热性能对特朗贝墙式被动式太阳能建筑的热性能具有重要影响。本文借助计算程序采用一维热网络模型对特朗贝墙体的集热性能进行了分析计算,计算中考虑了被绝大多数同类研究忽略的空气间层内玻璃盖板侧的自然对流换热,以及玻璃盖板与吸热面的辐射换热。在被动式太阳能建筑中用实测值对被动式太阳房的热性能进行了验证;并基于此计算方法,对特朗贝墙式被动式太阳能建筑的热性能进行了讨论。     

办公建筑外墙外保温系统绝热层经济厚度研究

以重庆地区某办公建筑为研究对象,采用能耗模拟软件eQuest,对采用不同绝热层(膨胀聚苯板)厚度(0～70 mm)外墙外保温系统的供暖、供冷能耗进行了模拟.通过节能效益及经济性综合分析,得到该办公建筑外墙外保温系统绝热层的经济厚度为30 mm.     

被动除湿太阳能房

提出了一种新型被动除温太阳能房。这种房屋的墙体构造是在Ｔｒｏｌｍｂｅ墙的空气间屋内插入一块含盐多孔板，从而形双层空气间层。     

A parametric study of Trombe walls for passive cooling of buildings

Air movement in a naturally-ventilated room can be induced through the use of a solar chimney or Trombe wall. In this work Trombe walls were studied for summer cooling of buildings. Ventilation rates resulting from natural cooling were predicted using the CFD (computational fluid dynamics) technique. The renoramlization group (RNG) k-ε turbulence model was used for the prediction of buoyant air flow and flow rate in enclosures with Trombe wall geometries. The CFD program was validated against experimental data from the literature and very good agreement between the prediction and measurement was achieved. The predicted ventilation rate increased with the wall temperature and heat gain. The effects of the distance between the wall and glazing, wall height, glazing type and wall insulation were also investigated. It was shown that in order to maximize the ventilation rate, the interior surface of a Trombe wall should be insulated for summer cooling. This would also prevent undesirable overheating of room air due to convection and radiation heat transfer from the wall.