床头送风改善夏季睡眠舒适度及质量的探索研究

从人体对送风的感知出发,基于安全和舒适的原则,通过短期的送风暴露实验确定整晚睡眠实验工况范围。对不同工况下整晚睡眠实验下的睡眠舒适性和质量数据进行对比分析,进而得到床头送风对睡眠的影响及合理的送风参数范围。研究得到夏季的最优工况为:环境温度为22℃,设计送风温度为21℃,控制目标(面部)风速在0.1±0.05m/s的范围之内。在最优床头送风工况下,主观睡眠质量和热舒适水平较高;同时送风对人体的皮肤温度影响不明显。不同年龄阶段的人群受床头送风影响程度存在差异。床头送风对儿童的积极影响较为明显,其次是成年人,而对老年人的睡眠影响则较不显著。床头送风能为夏季人体睡眠舒适度和质量带来积极的影响,有一定的应用价值。     

板式叉-逆-叉流新风换气机换热性能仿真

本文根据厂家新风换气机实物原型,建立计算模型。通过FLUENT数值模拟软件,对板式叉流-逆流-叉流空气．空气换热器送风面和排风面的速度场、温度场和压力场进行仿真。根据仿真结果得出换热器的热交换效率及送风面与排风面阻力,为新风换气机的设计和生产应用提供参考。     

夏季空调房间气流组织的数值模拟

应用计算流体力学方法对夏季空调房间两种送风参数下的室内气流组织进行了数值模拟,给出了速度场和温度场的分布状况,通过对比分析,指出舒适性空调夏季采用较低的送风速度能使室内温度场和速度场分布更均匀。     

会议室夏季空调送风方式的模拟分析

利用CFD软件分别对旋流风口送风方式和喷口送风方式下的会议室内的送风效果进行数值模拟,分析两种送风方式下的温度场和速度场,同时对气流分布性能和热舒适性评价指标进行比较,确定合适的送风方式。结果表明,旋流风口送风方式下的温度场和速度场更加均匀,热舒适性优于喷口送风方式。     

夏季空调送风参数对室内温度场影响的分析

空调的送风参数对室内热环境有着重要的影响,特别是对温度场的影响尤为显著.以在夏季空调房间有新风引入的情况下.着重比较了不同送风角度、送风速度下的室内温度场的分布.以此为基础,得出最佳的送风速度与送风角度.     

室内机位置对室内热舒适影响数值模拟分析

用CFD方法数值模拟了分体式空调器室内机在室内摆放位置不同时,在相同送风温度和送风速度下,对室内温度场、速度场以及热舒适性的影响.模拟结果表明:相同送风温度和送风速度情况下,不同的室内机位置产生了不同的室内温度场、速度场;与室内布局相适宜的室内机摆放位置可以改善室内舒适度.     

使用风机盘管的房间的舒适性实测研究

本文运用实测方法,对一采用风机盘管设备的办公室内的温度场、速度场进行了测量,并运用实测数据对风机盘管的舒适性进行了分析,结果表明舒适性不能满足要求。设备选择过大、送风温差过大、新风短路是造成这一现象的主要原因。在实际工程中,对风机盘管的使用应注意舒适性的要求,风机盘管的选择要恰当,同时应注意配套的新风机组。     

工位空调送风气流微环境评价

模拟了三种送风速度下送风气流在人体活动区形成的速度场、温度场及PMV的分布，结果表明人员活动区存在送风不均匀和温度分层现象，有助于解决吹风感；PMV值在 1和-1之间，可以满足人体热舒适要求。     

条缝型送风的船用VAV系统热舒适性研究

针对船舶舱室的特点,本文分析了舱室内采用可使送风气流均匀的条缝型送风方式的VAV空调系统的气流组织,并用CFD研究了舱室分别在100%、81%、60%送风量时的热舒适性,得出了舱室在四个典型截面处的速度场、温度场、平均空气龄、PPD和PMV的分布。结果显示,在工作区内,风速均小于0.3 m/s,且在1.2 m与0.2 m处的温度差小于3℃,速度场和温度场分布都比较较均匀;PMV指标在0左右,人体感觉舒适;PPD指标在10%以下,证明采用条缝型送风方式的各个气流组织评价指标完全符合热舒适性规范要求。     

隔断式风机盘管工位空调系统气流组织与微环境评价

采用K-ε三维湍流模型对一典型办公室工作区微环境进行了数值模拟,对三种送风速度下工作区的温度场、速度场以及人体吹风感和预期不满意百分率进行了分析研究。结果表明,房间温度呈分区分布,工位送风效率较高,可实现总体节能;在合适的送风速度下,可避免吹风感,保证良好的热舒适性。     

Displacement Ventilation - the Influence of the Characteristics of the Supply Air Terminal Device on the Airflow Pattern

Displacement ventilation is acknowledged to be an efficient system for the removal of contaminants and excess heat from occupied zones of rooms. However, airflow rates, temperature and the design of the air supply device strongly influence the parameters which determine thermal comfort. This paper reviews experiments and theoretical models which show the connection between these parameters. The width and shape of the air supply device have been varied, and a porous media has been used on the inlet area of the air supply device. The velocity and temperature profiles have been measured. The results presented show also that the flow can be described with respect to width and form of the profiles for temperature and velocity. The flow does not operate like a turbulent jet due to thermal stratification. It is shown that the Archimedes number of the supply air is the parameter which determines the air velocity in the area close to the floor. (The Archimedes number is here defined as the ratio between buoyancy and inertia forces.) The results show that it is possible to remove considerable amounts of excess heat from a room, typically 40-50 W/m², without exceeding the limits for thermal comfort. However, this requires relatively high airflow rates and supply air terminal units at least along one of the walls.     

厦门某海滨住宅夏季自然通风与室内热环境实测与分析

本文采用自动记录仪,对厦门某海滨住宅夏季自然通风与室内热环境进行实测。根据测得的自然通风时段,分析了自然通风对房间风速及室内热环境的影响。主要结论有:(1)在自然通风条件下,房间白天室内风速均值及波动值较夜间大。(2)房间在自然通风时段,室内气温均值略低于室外,室内气温波动明显低于室外且各房间气温波动差别不大;房间在非自然通风时段,室内气温均值与室外气温相当,室温变化相当平缓。(3)无论是自然通风还是非自然通风,房间的黑球温度与室内空气温度差别很小。(4)当房间处于非自然通风状态时,室内热环境总是处于"不可接受"水平,当房间处于自然通风状态时,其室内热环境几乎全时段达到"可接受"水平,且有的房间在某些时段可达到"热舒适"水平。     

南方民宅屋顶架空遮阳网对室内外热环境的影响

为了解南方民宅屋顶自发搭建的黑色遮阳网对室内外热环境的防热效果,以两个典型民宅为研究对象对其进行实测研究,一个是厦门集美兑山村民宅,另一个是厦港片区民宅为研究对象,在晴热天气测试其室内外气候参数,对比包括遮蔽房和无遮蔽房的空气温度、湿度、黑球温度、风速、顶棚表面温度、室内热舒适PMV值、屋顶地表温度、屋顶室外热舒适SET值,结果表明黑色遮阳网对室内的遮蔽房具有明显的防热效果,白天及其他大部分时间遮蔽房比无遮蔽房的空气温度、黑球温度、顶棚表面温度、室内PMV值都明显较低,并且下午随着日照减弱各个指标的降温也更快、幅度更大、显著缩短高温的持续时间;证实黑色遮阳网的防热效果对于屋顶灰空间作用不明显,却对于灰空间下方的遮蔽房间有明显作用。     

Thermal Comfort in the Near-Zone of a Radiator Air Device

Abstract The near-zone of an air inlet device is the most critical part of a room as regards fulfilment of the thermal conform demands. An acceptable solution for residential buildings can be to supply the outdoor air through an air device placed behind a radiator. Such a device provides a mechanical exhaust system that supplies pre-heated outdoor air. Normally radiator air devices are located below a window and a window-sill. To examine the influence of a window-sill placed above an air device, several different positions and breadths of sills were tested. Air velocities and air temperatures were measured at distances within 0.50 m from the device. The measurements show that thermal comfort is strongly dependent on the location of the window-sill in relation to the air device. The degree of turbulence intensity affects the percentage of dissatisfied people due to draught. The velocity measurement system used in this study allows variation of the time constant of the system. When different time constants were used, the measured turbulence intensity varied considerably. Some measurements were carried out with the radiator switched off. In these cases different air velocities were measured, depending on the orientation of the sensors. This seems to be due to the temperature and velocity gradients at the measuring points.     

独立新风系统(DOAS)研究(2):设计方法

介绍了低温送风独立新风系统的组成及全热交换器、新风机组、末端设备、风道的设计计算，分析了其热湿平衡，给出了一个工程设计实例。     

Determination of particle concentration in the breathing zone for four different types of office ventilation systems

Many factors affect the airflow patterns, thermal comfort, contaminant removal efficiency and indoor air quality at individual workstations in office buildings. In this study, four ventilation systems were used in a test chamber designed to represent an area of a typical office building floor and reproduce the real characteristics of a modern office space. Measurements of particle concentration and thermal parameters (temperature and velocity) were carried out for each of the following types of ventilation systems: (a) conventional air distribution system with ceiling supply and return; (b) conventional air distribution system with ceiling supply and return near the floor; (c) underfloor air distribution system; and (d) split system. The measurements aimed to analyse the particle removal efficiency in the breathing zone and the impact of particle concentration on an individual at the workstation. The efficiency of the ventilation system was analysed by measuring particle size and concentration, ventilation effectiveness and the indoor/outdoor ratio. Each ventilation system showed different airflow patterns and the efficiency of each ventilation system in the removal of the particles in the breathing zone showed no correlation with particle size and the various methods of analyses used.     

Thermal comfort and IAQ assessment of under-floor air distribution system integrated with personalized ventilation in hot and humid climate

The potential for improving occupants’ thermal comfort with personalized ventilation (PV) system combined with under-floor air distribution (UFAD) system was explored through human response study. The hypothesis was that cold draught at feet can be reduced when relatively warm air is supplied by UFAD system and uncomfortable sensation as “warm head” can be reduced by the PV system providing cool and fresh outdoor air at the facial level. A study with 30 human subjects was conducted in a Field Environmental Chamber. The chamber was served by two dedicated systems – a primary air handling unit (AHU) for 100% outdoor air that is supplied through the PV air terminal devices and a secondary AHU for 100% recirculated air that is supplied through UFAD outlets. Responses of the subjects to the PV-UFAD system were collected at various room air and PV air temperature combinations. The analyses of the results obtained reveal improved acceptability of perceived air quality and improved thermal sensation with PV-UFAD in comparison with the reference case of UFAD alone or mixing ventilation with ceiling supply diffuser. The local thermal sensation at the feet was also improved when warmer UFAD supply air temperature was adopted in the PV-UFAD system.     

昆明地区夏季居住建筑室内热环境测试及热舒适调查

对昆明市200户住宅夏季室内热环境参数进行了实测,并进行了现场问卷调查。分析了室内温度、相对湿度、风速、人员服装热阻的分布频率,统计得出了昆明地区住宅夏季室内热环境及人体热舒适的基本情况,并分析了室内热环境改善措施。调查发现,昆明市居民夏季普遍通过开窗进行自然通风以降低室内温度,在非空调条件下约有90%的居民的热感觉在舒适范围内。     

下送风空调气流组织设计方法

介绍了下送风气流组织中影响人体热舒适的四个主要因素：送风口型式，送风口到人体的距离，送风速度，送风温度。按因素重要性和最佳舒适性要求，提出了两种气流组织设计方法。     

一次回风送风再热与新风预冷互补的节能研究

对于一次回风空调系统,夏季工况,当空调区湿负荷较大时,采用露点送风只能保证设定温度,而湿度将会偏大,影响人体热舒适;若增加再热,又会出现冷热抵消现象。提出了利用室外新风热量再热来改善室内热舒适状况的方案。通过工程案例计算分析,结果表明:利用新风再热可减少再热送风系统6%~15%的能耗,认为送风再热与新风预冷互补措施能在一定程度上降低空调能耗,提高室内热舒适。