具有过滤功能的通风墙体性能研究

基于实现建筑物建能减排的目的,考察了具有过滤功能的通风墙体的引风性能,通过实验测试了热压、风压及热压风压耦合工况条件下通风墙体的引风量,为其在建筑中的实际应用提供可靠的理论基础。实验结果表明风压的驱动可在一定程度上补充室内环境对室外新风量的要求,但是热压的单独引风作用相对较小,尚需配合自然或半机械的通风方式共同作用。除此之外,研究发现集热面的保温隔热问题对引风量的大小有很大的影响。     

基于CFD的恶臭气体排风系统的模拟分析

以武汉某污泥好氧发酵项目为研究对象，利用CFD数值模拟技术，以发酵槽排风管路及风口的布置形式作为切入点，对厂房内排风系统进行模拟、分析。结果表明，该工程排风系统无法实现各点位均匀排风，靠近排风风机的风口风量大，而远离风机的排风口风量小，这与实际工程情况符合。针对分析结果，提出了优化方法并进行分析，模拟结果表明调整风口开度和风管尺寸两种优化方法都可以实现风口均匀排风目的。     

循环流化床锅炉风机节能改造及效果

单机效率低、风量风压富裕度大、风门挡板节流调节是CFB锅炉风机电耗大的主要原因,根据2台75 t/h CFB锅炉实际运行情况和测试结果,通过量体定做高效节能型风机提高单机效率,采用变频调速改造降低节流损失,采取优化运行方式对风机进行节能降耗,这些措施获得了成功,取得了良好的经济效果和社会效益.     

净化空间系统的数学模型与变频应用

对初效、中效和高效过渡器及通风管路，送风机建立数学模型，分析了过渡器和通风管道在系统运行过程中阻力变化对送风量、室内洁净度、室内正压、新风量的影响。提出应用变频调速技术使系统送风风机达到恒送风量，解决系统运行中送风量的衰减问题，达到节能目的。     

送风管系统水力平衡及风口风量实验测试

送风管系统是将空调集中处理后的空气送入室内的系统。送风管系统保证了人们对室内环境舒适性及卫生要求,而风管水力平衡能使空调通风性能达到最佳状态。为得到送风管系统的水力平衡规律以及风口风量的变化关系,文中通过对安装有多翼式离心通风机DT-(A)-18的送风管系统调试测量,整理分析各个风口之间的风量随阀门开度变化的管网阻力特性。风管系统在特定风量下运行,利用基准风口调整法调节阀门,进而改变管网中管段的阻力,保证系统更好地满足用户的需求     

通风设施管理规定

a）通风部门做好系统的调整,尽量减少风卡以自然分配风量为主; b）爱护通风设施做到：风门严禁同时打开或用车撞风门,风门损坏及时汇报通风调度,如果影响系统风量受影响区域停电、撤人修复后再生产,安监调度组织分析处理; c）通风设施由通风部门管理,其它单位无权移动、拆除等权力，如需要拆除、移动需要提前和通风部门联系； d）严禁跨入栏杆、拆除栏杆、闭墙、风卡等通风设施。     

通风设施管理规定

<正>a)通风部门做好系统的调整,尽量减少风卡以自然分配风量为主;b)爱护通风设施做到:风门严禁同时打开或用车撞风门,风门损坏及时汇报通风调度,如果影响系统风量受影响区域停电、撤人修复后再生产,安监调度组织分析处理;c)通风设施由通风部门管理,其它单位无权移动、拆     

浅谈高层建筑防烟系统

论述高层建筑防烟系统土建设计、施工质量以及风压、风量的计算对防烟系统的影响。     

浅谈高层建筑防烟系统

论述高层建筑防烟系统土建设计、施工质量以及风压、风量的计算对防烟系统的影响。     

净化空调系统的数学模型与变频应用

对初效、中效和高效过滤器及通风管路 ,送风机建立数学模型 ,分析了过滤器和通风管道在系统运行过程中阻力变化对送风量、室内洁净度、室内正压、新风量的影响。提出应用变频调速技术使系统送风风机达到恒送风量 ,解决系统运行中送风量的衰减问题 ,达到节能目的     

脉动热管用于空调排风余冷回收的试验研究

设计加工1台脉动热管式换热器,用于夏季工况空调排风的余冷回收。通过实验,分析了风速、新排风温差等因素对余冷回收效率的影响,以及两侧压力损失随风速的变化情况。结果表明,余冷回收效率随新风、排风温差增大而升高,随风速的增大而降低。该换热器具有一定的优势,但还需进一步改进结构,以提高其效率。     

Numerical simulation of cooling performance of wind tower (Baud-Geer) in hot and arid region

In the present study, an attempt is made to study the cooling performance of a wind tower in a hot and dry region, Yazd, in Iran. For the relevant experiments and numerical studies, at first, the temperature and wind velocity inside and outside of the wind tower measured. Based on four-day measurements during last summer, a computer program was designed with language C⁺⁺ to solve the equations. Also in the study the effects of parameters including wind tower height, variety of the materials used in the wind tower walls, the amount of vaporized water, the temperature of input and output air, the wind velocity and the relative humidity were investigated.Furthermore, to develop, a natural flow of air, for days without blowing a wind the role of solar chimney was considered.Finally, to evaluate the method of integral view and take information about streamlines of airflow in wind tower (Baud-Geer), velocity, pressure, humidity, temperature and density profile of fluid, Fluent software is applied to analyze the air flow in the wind tower in differential view for three-dimensional and steady state conditions with water spraying at the top of wind tower.The results indicate that the evaporative cooling is very effective in a hot and dry region. The temperature decreases considerably, if the wind towers are equipped with the water vaporization system. This causes the air becomes heavier and a natural motion of air through downside of wind tower to be produced.     

微细管束换热器结霜及流动对流换热特性实验研究

利用可视化换热器性能实验台测试了微细管束表面在无换热、大温差、凝露条件下不同风速工况的流动损失与空气侧换热系数。同时探究了超低温工况下,相对湿度和风速对微细管束换热器流动换热特性影响。相对湿度增大,湿空气释放潜热增加,结霜量增大,换热器前后压损增加。高速气流具有剪切作用,风速增大会导致结霜迟滞。     

Session A: Les matières premières alcooligènes

Various commercially available natural ventilation devices supply fresh air without mechanical assistance. These devices offer a low-energy alternative to mechanical air handling units. However, they often cannot satisfy recommended ventilation rates due to their dependence on both macro- and microclimate wind speeds. This work examines the feasibility of achieving the recommended fresh air delivery rates without impacting on the device energy requirements. A numerical investigation is carried out using a standard passive stack device geometry combined with a simulated low-powered axial fan. The investigation shows that a low-induced pressure of 20 Pa is enough to satisfy the legislative requirements. Depending on the macroclimate conditions, this induced pressure could be generated from a commercially available solar-powered system. As the fan system is only used in periods of low external wind velocities (1 m/s), it is termed a passive-assisted stack.     

Effects of stacked condensers in a high-rise apartment building

The effects of condensers installed in the stacked air-conditioning plant rooms of a high-rise apartment building were studied numerically. The performance of the condensers was evaluated using the coefficient of performance (COP) and condenser group performance indicator (CGPI) parameters. The effects of wind direction, wind velocity, and the arrangement and location of the condensers were investigated. The performance of condensers above the 30th floor was seriously degraded due to the stacking effects. The heat dissipation performance of the condensers in the higher floors dropped significantly when the frontal wind was greater than 4 m/s and the side wind was greater than 8 m/s. The condenser should be arranged in such a manner that the fan of the condenser faces the outside of the building to exhaust the hot air directly to the outside. To prevent the hot air from reentering the air-conditioning plant room and to allow fresh air to enter instead, the condenser considered in this study must be located at the lower left corner of the air-conditioning plant room.     

Evaluation of pressure coefficients and estimation of air flow rates in buildings employing wind towers

Wind pressure coefficients at various openings of a wind tower were determined by testing a scale model of the building in a boundary layer wind tunnel. Wind towers (or Baud-Geers) are structures which have been employed in Iran and neighbouring countries for natural ventilation and passive cooling. Tests were conducted on an isolated tower, the tower and adjoining house, and the tower and house surrounded by a courtyard. The wind pressure coefficients at the tower and house openings were determined at various wind angles for two types of terrain: suburban and open country. The air flow rates were then estimated from a knowledge of the wind pressure coefficients at the building apertures. It was concluded that the presence of a courtyard around the structure and the angle of incidence of the wind influence the rate and the direction of air flowing from the tower to the house. If leeward openings of the tower can be closed (for example, by automatic dampers) restricting the air leaving these apertures, the air flow rate from the tower to the house can be greatly increased. The results of this investigation are believed to provide assistance to architects and engineers in the design of wind towers for desired ventilation rates in buildings.     

垂直轴风力机叶片翼型结冰的数值计算

为研究寒冷气候条件对直线翼垂直轴风力机叶片表面结冰的影响,对该种风力机叶片常用的NACA0015翼型进行了翼型结冰的数值模拟计算.计算基于二维定常不可压缩流体的N-S方程,并引入离散相模型DPM.参照实际风力机野外工作环境参数,通过改变风速和空气中水滴流量等条件,计算了在8种典型攻角下的翼型表面结冰分布情况.结果表明:气流中所含的过冷水滴量和风速是影响风力机翼型表面结冰的关键因素;风速较低时,水滴流量的影响占主导作用;翼型攻角不同,其表面结冰的厚度、面积和生长趋势不同.在一定攻角范围内,翼型表面的结冰面积随翼型迎风面积、风速和空气中水滴流量的增加而增大.在一定条件下,结冰面积可达到翼型面积的30%以上.     

风力机叶片周围流场的PIV测试

在直流式低速风洞中,应用二维PIV系统,对水平轴风力机叶片周围流场进行了测试,揭示了在设计风速下,气流以相对风速流过叶片时,叶片周围流场的分布规律.在各个测试截面内,吸力面气流速度均高于相对风速,压力面气流速度均低于相对风速;气流沿叶片表面流动未发生分离时,叶片吸力面速度最大区域位于截面翼型最大厚度处;发生分离时,越靠近叶根位置,吸力面速度最大区域越向下游迁移,且分离点越靠近翼型前缘;叶尖部位存在从翼型后缘看为逆时针旋转的涡流,呈螺旋状向下游传播.PIV测试分析为叶片最佳空气动力学特性的设计提供了指导,并取得了大空间单烟雾发生器直流风洞的PIV实验经验.     

Development of a flow distribution and design model for transpired solar collectors

Unglazed, transpired solar collectors offer a low-cost, high-efficiency means for preheating outside air for ventilation and crop drying applications. Although large building wall applications for these collectors have generally performed well in the field, many have exhibited poor flow distribution which can prevent maximum efficiency from being achieved. The objective of this work was to develop a computer model which would run quickly on a personal computer and allow designers of transpired collectors to easily adjust geometric parameters to achieve reasonable flow uniformities and to determine efficiencies. This paper describes how this model was developed and includes results from model runs. In order to allow the model to run quickly on the PC, pipe network methods were used to develop a set of simultaneous equations in the unknown flow rates. Previous research results on heat exchange effectiveness, pressure drop, and wind heat loss were incorporated.     

单侧进风层燃炉的横向均匀配风的试验研究

改善单侧进风层燃炉的横向配风均匀性可以提高锅炉运行效率。利用测压探针和示踪粒子,实测了空风室、流线型隔板、上直隔板、下直隔板等四种风室模型结构多个工况下的配风均匀性。对风室进口处隔板的具体结构进行了分析讨论和多次试验改进,提出了一种可以兼顾气流平衡和均流的结构。通过对比发现,下直隔板风室是一种比较理想的风室结构,给出了结构尺寸的建议,可用于层燃炉风室的设计和节能改造。