高大钢结构厂房通风防结露问题的研究

本文探究上海某钢铁厂的某冷轧轧后库厂房的结露问题,对该厂房的室内温湿度、室外温湿度、壁面温度、门窗进出风状态等进行了长期测量。在此基础上,运用CFD模拟对该厂房实际测试工况与假设的屋顶机械通风工况分别进行模拟分析。同时结合露点温度和内壁面温度的计算,得出机械通风对钢结构屋顶结露问题的影响规律。     

浅谈工业厂房的通风设计

介绍了工业厂房通风的主要形式为自然通风、机械通风和混合通风,并对三种通风形式设计应注意的问题进行了探讨。对于工业厂房通风的设计,必须结合实际进行综合考虑,正确选择通风方式,达到改善室内空气环境的目的。     

某柴油发动机试验厂房通风降温的数值模拟分析

针对某柴油发动机试验厂房试验过程产生大量余热问题,进行该厂房通风降温方案的数值模拟分析。通过建筑环境和工艺过程建立可供分析的物理模型,选用计算流体动力学的Realizable k-ε模型和组分运输模型作为计算工具。设计了传统的全新风、室外新风蒸发冷却、室外新风蒸发冷却+热污染区环境蒸发冷却三种技术方案进行模拟计算。结果表明,以传统的全新风通风方式尽管能够把室内的热量排出,但未解决人员工作区环境温度超标问题。室外新风蒸发冷却通风方式对比全新风方式,通风量下降31%,可以解决大部分人员工作区环境温度问题。室外新风蒸发冷却+热污染区环境蒸发冷却对比全新风方式,通风量下降43%,可以完全满足人员工作区环境温度要求。     

冷轧厂某机组对室内热环境影响的研究

通过现场实测和理论分析,对冷轧厂某机组的散热机理进行了研究,发现炉膛内温度在800 ℃左右变化时,机组散热对厂房内环境温度的影响基本是恒定的,主要影响区域集中在炉体周围各层工作平台;厂房内工作平台环境温度与室外温度相关,炉体周围工作平台温度在高度方向上梯度明显.运用CFD软件进行了数值模拟,模拟结果与实测和理论分析结果有很好的一致性.指出对厂房进行合理通风改造能改善室内热环境.     

核电厂常规岛汽轮机房通风系统设计模拟

介绍了该汽轮机房的工程概况、通风量的计算及主要发热设备的布置。根据屋顶通风机位置和风量的不同设计了7种工况,采用CFD软件对其室内热环境进行了模拟。基于对模拟结果的分析评价,提出了增设诱导风机和新风机的优化方案,模拟结果表明厂房内的温度达到设计要求。     

白鹤滩水电站通风空调系统设计

白鹤滩水电站地下厂房的洞室群布置复杂,洞室气流交错连通,厂内电气设备多且发热量大,通风空调系统设计尤为重要。确定了地下厂房采用机械通风为主、空调和除湿为辅的通风空调设计方案,提出了地下厂房“四进五排”的气流组织。结合厂房布置、电气设备发热量和通风空调系统划分情况,完善了各区域通风空调系统的设计方案和气流组织,分析了各区域通风空调系统的通风量和设备布置,提出了按季节调节风机和空调的运行方案,通风空调系统能满足地下厂房的温度、湿度和通风换气要求。     

柴油发电机厂房通风和冷却系统的设计探讨

本文介绍了为柴油发电机厂房服务的通风和冷却系统的设计要求和设计思路，详细分析了系统通风量等参数的计算方法，并提出了合理化建议。通过系统的合理设置，能够使柴油发电机厂房的环境满足设计要求，为柴油发电机组及辅助设备的正常运行提供必要的保障。     

抽水蓄能电站地下主厂房通风空调运行优化

根据抽水蓄能电站的运行调度方式和厂房通风流程的特点,提出将进风洞末端的空气温度作为控制电站通风空调系统运行方案转换的参数,按照满足所有场所的温度参数不超过设计值的原则,推导出通风和空调方案转换的临界温度的计算方法,给出了各温度阶段对应的通风空调运行方案.以南方某装机容量为1200MW的抽水蓄能电站为例,根据计算所得的临界温度,将进风洞末端全年空气温度划分为4个温度阶段,得到优化后的运行方案,其年运行费用将显著下降.     

工业热厂房热压通风与机械排风联合运行研究

为研究热压通风与机械排风联合运行下的复合通风系统在工业热厂房中的作用规律,搭建了具有集中热源和屋顶机械排风装置的复合通风实验台,并在实验基础上利用CFD数值模拟技术建立了复合通风数值预测模型。提出了有效通风量和有效通风比两个参数并结合温度效率对室内通风进行评价,得到了工业热厂房中机械排风口数量及其分布形式和机械排风量对复合通风效果的影响规律。研究结果为工业热厂房中热压通风与机械排风联合运行下的复合通风设计提供参考。     

大空间热压通风与局部机械通风耦合换气研究

本文采用计算流体动力学方法模拟研究了热压自然通风和局部机械送风相结合的复合通风工业厂房室内气流组织和热流分布特征。研究了在不同热源强度,不同机械送风压力下厂房内气流分布,通风量,温度垂直分布以及排温效率的变化规律。结果表明:排温效率随着热源强度的增加而降低,随着机械送风强度的增大,排温效率先升高后降低再升高最后趋于平稳。研究结果可以为工业厂房通风系统设计提供一定的参考。     

Improvement of natural ventilation in a large factory building using a louver ventilator

When heat generated from facilities inside a large factory building is not discharged outside the building due to a stagnant ventilation flow, the working environment of workers becomes worse, and the cooling of high-temperature products is delayed. In this study, wind tunnel tests were conducted to investigate the natural ventilation of entrained air inside a large factory building. The scale-down factory-building models were embedded in a simulated atmospheric boundary layer (ABL), and the mean and fluctuating velocity fields were measured using a two-frame particle image velocimetry (PIV) technique. For the original factory model, some of the outdoor air came in the factory building through the one-third open windward wall, while the stagnant flow region existed in the rear part of the target area. In order to improve the indoor ventilation environment of the present factory building, three different types of the louver ventilator were attached at the upper one-third open windward wall of the factory model. Among the three louver ventilators tested in this study, the ventilator model ?3 with the outer louver (θ_o=90°) and the inner louver (θ_i=−70°) was found to improve the natural ventilation inside the target factory-building model. It increased the flow rate of the entrained air by aligning the outer louver blades with the oncoming wind and guiding the entrained air down to the ground surface with the elongated inner louver blades.     

Coupling of thermal mass and natural ventilation in buildings

The coupling of thermal mass and natural ventilation is important to passive building design. Thermal mass can be classified as external thermal mass and internal thermal mass. Due to great diurnal variation of ambient air temperature and solar radiation intensity, heat transfer through building envelopes, which is called external thermal mass, is a complex and unsteady process. Indoor furniture are internal thermal mass, affecting the indoor air temperature through the process of absorbing and releasing heat. In this paper, a heat balance model coupling the external and internal thermal mass, natural ventilation rate and indoor air temperature for naturally ventilated building is developed. In this model, the inner surface temperature of building envelopes is obtained based on the harmonic response method. The effect of external and internal thermal mass on indoor air temperature for six external walls is discussed of different configurations including lightweight and heavy structures with and without external/internal insulation. Based on this model, a simple tool is developed to estimate the indoor air temperature for certain external and internal thermal mass and to determine the internal thermal mass needed to maintain required indoor air temperature for certain external wall for naturally ventilated building.     

冷却顶板-置换通风空调系统分析

介绍了一种冷却顶板设计样式,同时对冷却顶板进行了换热分析。冷却顶板只能除去显热负荷,无法除去湿负荷,置换通风的除湿能力受到送风量的限制,当整个制冷系统处于温度最低点时,冷却顶板表面温度可能会降到室内空气露点温度以下,而出现结露的危险。为了保证冷却顶板表面不结露特别是在湿负荷较高的状况下, 本文提出了在冷却顶板表面形成干燥空气保护层的建议,同时以计算流体力学(CFD)的模型为基础,采用有限容积法对具有干燥空气保护层的冷却吊顶一置换通风系统的气流分布进行了模拟分析。     

Thermal simulation: Response factor analysis using three-dimensional CFD in the simulation of air conditioning control

The heat generated from an air-conditioning equipment or other thermal loads is distributed throughout a room by a three-dimensional airflow. This three-dimensional airflow creates a three-dimensional heat distribution in a room. To better understand building performance, we must integrate this spatial distribution into building simulations. Thus, three-dimensional computational fluid dynamics (CFD) analysis is necessary in design process because most conventional building energy simulations still employ a temperature that is averaged across the space of a room. However, usually only a few cases of CFD analyses are executable in real design process because of the large computational load they require. This paper presents a new, simplified method to calculate heat transport phenomena in rooms, based on a few cases of CFD analysis, and to integrate data into a nodal analysis. This method can be used to calculate an indoor environment, including the spatial distribution of temperature, with a computational load that is much lighter than it is in a simulation using CFD alone. Furthermore, in terms of precision, it is a far more reliable method than the conventional simulation, which assumes the perfect mixing of heat in a room. In the paper, we apply this method to simulate the control of air conditioning. Ordinarily, the reproduction of the phenomena shown in the calculation examples requires substantial manpower and costly computing resources for experimentation or CFD analysis. With our calculation method, it is possible to reproduce the same calculation results in a very short time with a PC. And we checked the potential to the practical use through a verification calculation with CFD analysis.     

武汉高校公共教室夏季热环境的实测研究

在对武汉某高校公共教学楼内多个公共教室进行室内热环境调查和实测的基础上,选择一间实验教室进行对比测试,测试结果证明该实验方法可靠。通过对公共教室和实验教室实测数据的分析和比较,指出无法进行夜间通风和不适宜的开窗方式是公共教室热环境不佳的主要原因。最后根据武汉地区气象资料,结合高校教学时段提出加强通风散热,缩小室内外温差以提高公共教室自然通风效率不仅能够改善公共教室室内热环境,也是减少空调能耗的关键。     

简易阳光间的太阳能应用分析

住宅的南向阳台对于住户来说,虽然使用面积有限,但带来的益处是人所共知的,可供人们眺望户外景致、打破的闭塞感以及丰富建筑立面造型等。如果合理地把阳台封闭起来,形成一个附加的过渡空间,在冬季,夜间有利于保持室内温度,减少热损失;白天还可收集太阳直接辐射并转化为热能,对房间起到加热作用,提高室内热环境水平。同样在夏季,利用封闭阳台与室内温度不同产生的热压作用,亦可达到通风致凉的目的。若再采取适当构造措施,如增加吸风口、扩大气流出入口的高度差,就可以大大改善室内通风效果。然而,寒冷、严寒地区封闭阳台在改善室内热环境方面有利人们早已认同,但对其原理却知之甚少,也没有理论、技术来指导设计和建设。因此,该文通过理论分析,总结出一些合理的构造措施,来指导设计、建设,使南向封闭式阳台能真正成为简易阳光间,改善室内热环境。     

Investigating the potential use of natural ventilation in new building designs in Turkey

The most economic air conditioning of living and working places can be achieved by natural ventilation if sufficient. This provides not only the circulation of clear air, but also the decrease of indoor temperature, especially, during hot summer days, provided that the temperature of clear air is lower than that of indoor. From the geometric optimization point of view, both size and position of windows in buildings are important parameters to obtain a uniform indoor air velocity distribution.In this study, the potential use of natural ventilation as a passive cooling system in new building designs in Kayseri, a midsize city in Turkey located at 38.44°N and 35.29°W, was investigated by computational fluid dynamics (CFD). Using the FLUENT 6.2 program, which employs finite element methods, indoor air velocity distributions with respect to changing wind direction and magnitude were obtained in living places of different dimensions. The simulation results suggest that natural ventilation can be used to provide a thermally comfortable indoor environment during the summer season in the study area. The study presents useful design guidelines for natural ventilation at both site planning and individual building levels.     

热源面积对室内热压自然通风的影响

针对具有内热源的民用建筑,采用计算流体力学(CFD)方法,通过改变热源面积对热压自然通风流场进行数值模拟分析,得出了不同热源面积下的通风量、排风温度及其变化规律,分析了不同工况下的温度场和速度场,得出了中和面高度和有效热量系数随热源面积的变化规律。结果表明:热源面积的变化主要影响房间下部的温度场,对通风量和排风温度的影响不大,对中和面高度和有效热量系数均有一定的影响。该结论为民用建筑自然通风系统的设计提供了理论依据。     

过渡季节应用自然冷源的设计方法

在计算通风空调切换温度基础上,提出过渡季应用自然冷源的设计及节能评估方法,通过采用过渡季通风量控制策略减少风机运行能耗.上海地区某高大厂房采用此方案,与过渡季空调方案相比,负荷率0.8时,空调主机年节能率为29.3％,卸载控制策略时的风机能耗为风机满载运行时的41％～56％.提出以日期作为通风空调运行切换依据,并定量分析不保证率与节能率的关系.     

开窗位置对室内风环境的影响

通过STAR-CCM+计算流体模拟软件,基于不同开窗位置的通风效果比较,以室内平均风速等参数作为通风效果的评价指标,对室内风环境进行了模拟与分析,提出关于建筑自然通风设计中开窗优化在实际项目中运用的必要性。