济南办公建筑自然通风工况下自然室温的研究

针对济南地区一办公房间,讨论不同的换气次数、围护结构和建筑朝向对自然室温影响的变化规律。指出夜间通风和节能50%的围护结构能获得适宜的自然室温,建筑朝向对自然室温的影响较小。     

薄板钢骨体系外围护结构对流通风层的传热计算

本文利用传热学知识计算得出薄板钢骨外围护结构墙体对流通风层的复合传热系数,证明外围护结构设置对流通风层是降低外围护热损耗的有效方法.     

考虑建筑房间内导热辐射与自然对流耦合时外围护结构对对流换热的影响

对具有导热和表面辐射换热相互耦合的建筑房间内的自然对流进行了数值研究。计算采用层流模型,为SIMPLE算法,QUICK差分格式。计算结果表明,辐射参与换热对流动将产生显著影响,会使房间内形成二次涡流。在自然对流的房间内,辐射换热比对流换热更占主导地位。当具有外围护结构时,导热效应使总对流换热有所增长(曲线的初始部分),但当导热系数比超过一定值时(kr≥10),再增加固体的导热性能,对房间内的流动和换热的影响就不明显了。从数值上证实了在实际建筑环境中,只要外围护结构的厚度达到一定数值就可达到隔热保温的要求。再增加厚度并不会得到更好的效果。     

严寒地区农村住宅围护结构保温改造分析

严寒地区多数农村住宅建筑围护结构热损失严重,造成其采暖能耗增加,强化建筑围护结构的保温性是提高建筑采暖效率的方式之一。以位于严寒地区的安达市某传统农宅为研究对象,采用EnergyPlus对该住宅围护结构的保温性能进行研究,并分析了建筑能耗情况,获得了建筑墙体、玻璃、屋顶等围护结构部位采用保温后的节能效率。研究结果表明：安达地区节能效率较好的墙体和屋顶保温材料为XPS保温板、玻璃窗结构形式为6mm+12mm+6mmLow-E低辐射玻璃;传统农宅采用建筑保温材料后,其节能率可达72.0%,从而降低了农村住宅采暖能耗,并可维持室内良好的热环境。     

夏热冬暖地区办公建筑围护结构改造节能经济性分析

对夏热冬暖地区某办公建筑进行能耗测试,利用能耗模拟软件TRNSYS对该建筑空调能耗进行模拟,分析空调冷负荷对于各围护结构的敏感性,对影响能耗显著的外墙、遮阳系数及建筑渗透率进行改造。利用NPV动态经济评价体系,在建筑运行时间内对26种改造方案进行节能经济性分析。结果表明,外墙中度强化、建筑渗透率高度强化及遮阳系数高度强化方案的经济收益值最大,改造成本回收年限较短,为经济性最优改造方案。     

太阳辐射下建筑围护结构的动态热平衡模型及实例分析

区别以往仅考虑太阳辐射的静态方法,建立了一个考虑围护结构蓄热和传热的动态的建筑围护结构热平衡模型,并用该模型计算了济南夏季某日某单栋建筑各围护结构外表面的温度。     

夏热冬冷地区变电站建筑围护结构传热系数测量

介绍了热流计法检测建筑围护结构传热系数的原理,通过现场检测某变电站建筑围护结构的传热系数,理论计算分析现场检测的传热系数的可信度,为变电站建筑节能检测工作指出一条可行的方法。     

广州地区建筑围护结构能耗分析

分析总结出广州地区建筑围护结构中不透明部分、半透明部分(玻璃窗)和朝向三个因素对建筑整体能耗的影响规律:围护结构中半透明部分比不透明部分的建筑整体能耗大,东西朝向比南北朝向的建筑能耗大。     

既有建筑的围护结构节能改造分析

以某办公建筑和住宅楼为模型,对其进行围护结构节能改造分析.通过计算比较改造前后室内负荷的变化,发现节能效果相当显著,证明在我国既有建筑围护结构节能改造存在相当大的潜力.     

自然通风条件下建筑围护结构及室内空气的温度计算

建立太阳照射和自然通风条件下建筑与室内、外环境的空气平衡方程与热平衡方程,以及沿围护结构厚度的非稳态一维导热方程,求解得到建筑围护结构和室内空气的温度。选取广州夏季某一天的气象参数,计算围护材料分别采用钢筋混凝土、灰砂砖砌体、浮石混凝土、橡木和平板玻璃情况下,从7时至19时一单室建筑围护结构及室内空气的温度。     

人工环境库诱导式温湿调控系统设计探讨

针对人工环境库温湿调控的特殊要求，设计了空气诱导式湿度调节与空气干式集中升降温处理的诱导式温湿度调控系统；对四种方向的温湿度调控过程进行了理论分析及设计计算，进而设计了“先调温后调湿”的配套自动控制流程，并以试验实例结果进行了讨论。结果说明该系统可提高人工环境库温湿调控可靠性及控制品质。     

自然对流温度场节能改造

本文通过热流理论分析和传热计算,指出了某一运行多年的自然对流温度场的不足,为了节能增效,采取了快捷的改造措施。工程竣工后试运转表明节能率可达50%,对所有自然对流温度场的改造具有普遍指导意义和重要参考借鉴作用。     

A new apparatus for measuring total hemispherical emittance of surfaces at room temperature

Radiation heat transfer is an important mode of heat transfer even in our life space at room temperature. Such radiation heat transfer is evaluated mostly by calculating the radiation energy exchange among surfaces in an enclosure. For this evaluation, knowledge of the hemispherical emittances of the constituent life surfaces is needed. However, there has not been a suitable technique for measuring the emittance of each surface in the life space at room temperature. In the present work we develop a new apparatus for measuring total hemispherical emittances of real surfaces at room temperature. The apparatus consists of a total radiation flux meter and a Peltier element cooler to cool the flux meter surface from the back, and measure the net total radiation flux from the specimen surface to the surrounding surfaces to determine the total hemispherical emittance of the specimen surface. This apparatus is effective to measure total hemispherical emittances of surfaces at room temperature on site. We apply the developed apparatus to measure the total hemispherical emittances of various surfaces in the life space, such as metals, human skin, cloth, floor mat, wood, glass, brick tile, stone, cement, plant leaves, etc., and demonstrate the feasibility of the apparatus. © 2011 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library ( wileyonlinelibrary.com/journal/htj ). DOI 10.1002/htj.20349     

Analytical optimization of interior PCM for energy storage in a lightweight passive solar room

Lightweight envelopes are widely used in modern buildings but they lack sufficient thermal capacity for passive solar utilization. An attractive solution to increase the building thermal capacity is to incorporate phase change material (PCM) into the building envelope. In this paper, a simplified theoretical model is established to optimize an interior PCM for energy storage in a lightweight passive solar room. Analytical equations are presented to calculate the optimal phase change temperature and the total amount of latent heat capacity and to estimate the benefit of the interior PCM for energy storage. Further, as an example, the analytical optimization is applied to the interior PCM panels in a direct-gain room with realistic outdoor climatic conditions of Beijing. The analytical results agree well with the numerical results. The analytical results show that: (1) the optimal phase change temperature depends on the average indoor air temperature and the radiation absorbed by the PCM panels; (2) the interior PCM has little effect on average indoor air temperature; and (3) the amplitude of the indoor air temperature fluctuation depends on the product of surface heat transfer coefficient h_in and area A of the PCM panels in a lightweight passive solar room.     

自然通风的策略形式及模拟分析

介绍了自然通风的策略形式 ,阐述了采用网络法和CFD对自然通风的模拟分析。最后提出了自然通风的策略选择和模拟分析中要注意的几个问题。     

An experimental and mathematical study of efforts of a novel photovoltaic‐Trombe wall on a test room

A novel photovoltaic‐Trombe wall (PV‐TW) is proposed and investigated experimentally and theoretically in this paper. The PV‐TW was installed at the south‐facing external wall of an environmental chamber that carried two identical test rooms. Both of the test rooms have a double window of the same size. One test room was installed with the PV‐TW (known as the PV‐TW room), and the other without PV‐TW (known as the reference room). The influence of the PV‐TW on the thermal environment of the test room was investigated under different operating conditions. The experimental results show the dual benefits of the PV‐TW system: improving the room thermal condition and at the same time generating electricity. Compared with the reference room, the maximum indoor temperature was found to be 5–7°C higher in winter, and the daily electrical output reached about 0.3 kWh with a PV cell area of 0.72 m². Also, a detailed model is given to evaluate the performance of PV‐TW theoretically, and the PV‐TW room is simulated under one certain operating condition. The simulated and measured air temperatures of PV‐TW room are found to be in good agreement. Copyright © 2007 John Wiley & Sons, Ltd.     

自然工质低温复叠式制冷循环的热力学分析与比较

介绍了用于低温环境下采用自然工质CO2、NH3和R2903的复叠式制冷循环，介绍和分析了CO2、R290和NH3的物性特征，并且进行了复叠式制冷循环的热力学理论分析，通过计算得出了不同蒸发温度下的最佳低温循环的冷凝温度和最流量比。通过CO2－NH3，CO2－R290和NH3－NH3复叠式循环的比较，可以看出CO2－NH3、CO2－R290的复叠式制冷循环在低温制冷条件下有明显优势。     

户内主变压器室通风散热优化设计研究

建立某110 kV户内主变压器室通风散热三维模型,利用计算流体力学方法研究了变压器室自然通风临界温度,机械排风速率,进、出风口位置及大小对其散热特性的影响,并分析了原始方案与优化后方案中变压器室内的流动特性。结果表明：原始方案中变压器自然通风临界温度约为22℃,且随着室外环境温度升高,自然通风时室内变压器靠近底部区域易出现热量堆积,造成变压器散热量无法及时排出,进而对变压器的安全、稳定运行造成危害。在自然通风临界温度为22℃时,所需最小机械排风速率为2.56 m·s^-1。增大进、出风口面积以及降低出风口位置均有利于增强变压器室内散热效果,使变压器室排风温度显著降低。将两个风机位置调低可使出风口平均温度降低1～2℃。与原始方案(风量2.56 kg·s^-1)相比,优化后方案(风量降低至1.50～2.00 kg·s^-1)可满足该变压器室通风散热需求,从而达到优化风量、降低噪声的目的。