采光顶下微气候形成效果测试与分析

为了分析采光顶下微气候的形成效果,对沈阳万达广场室内步行街的普通玻璃采光顶和外镀吸热膜采光顶两种工况下的垂直温度分布、照度、平均辐射温度等参数进行了现场实测,对人体舒适性与热感觉进行了问卷调查,同时对不同遮阳形式采光顶进行了对比分析。结果表明:采用外镀吸热膜的采光顶,室内温度波动最小,平均辐射温度最低,人员活动区最高位置温度仅为27. 5℃,人体热舒适和热感觉最好。内遮阳对室内热环境有一定积极的影响,但很难在根本上消除室内辐射得热。外镀吸热膜和内遮阳工况对室内照度均能维持在4. 18 klux左右,普通玻璃采光顶室内照度最高。为现代大型商业建筑不同形式采光顶的选择提供了参考。     

外窗遮阳对室内温度的影响

建筑遮阳系数对建筑能耗和室内热环境均有影响,而室内空气温度作为影响热舒适的主要因素与窗户遮阳存在必然联系.采用DOE-2软件计算方法分析遮阳系数变化时室内温度降低的分布情况,说明夏季设置外遮阳对室内热环境改善的效果.     

广东地区农村居住建筑热环境现状及改善措施

对广东地区农村居住建筑及其热环境现状进行了调查,发现农村居住建筑普遍缺乏有效的遮阳隔热措施,仅22.1%的居民对热环境感到满意,居民普遍期待改善室内温度。通过对26~30℃条件下、29℃及30℃辅助机械通风条件下的环境进行热感觉投票实验,结果表明,当室内温度在28℃以下时,开启门窗进行自然通风可达到热舒适要求;室内温度在29~30℃时,利用电风扇可达到热舒适要求。农村地区居住建筑热环境改善重点在于采用良好的自然通风、建筑遮阳及隔热措施,有效降低室内温度。     

内遮阳加屋顶排风对中庭热环境的影响效果分析

内遮阳在减少由于太阳直射引起的室内得热的同时会使遮阳材料与玻璃之间形成高温空气层,并以长波辐射的形式向中庭传热,继续影响室内热环境和人体热舒适性条件。通过模拟计算的方法分析在内遮阳与玻璃之间加装排风机后室内热环境与人体辐射换热量的改善效果。结果证明,顶排风机可以将内遮阳与玻璃之间的高温空气及时排出,降低中庭高楼层环境的平均辐射温度,并且能够显著降低高楼层环境与人体的辐射换热量,提高中庭环境的热舒适性。     

建筑中庭玻璃屋面内遮阳对室内环境影响分析

针对中庭玻璃屋面内遮阳对室内环境以及能耗的影响,在有无内遮阳工况下分别进行了自然采光照度测试、中庭玻璃屋面内表面温度测试、室内温度测试以及中央空调冷量监测。结果表明,在遮阳工况下,区域1的照度全天有3.5h满足采光标准,超过了300 lux,区域3在17∶00前均满足标准;遮阳卷帘内表面温度降低了0.6~7.7℃,钢结构表面温度降低了4.3~12.5℃;区域2温度在同一时刻最高降低了5.9℃,区域1温度在2种工况下基本维持在27℃左右,同时有遮阳时的空调能耗比未设置内遮阳时下降了6.67%,说明内遮阳可以改善室内热环境,并对降低室内空调冷负荷具有一定的作用。     

日较差对居住建筑夜间通风室内热环境的影响

为了研究不同日较差情况下,夜间通风对室内热环境的影响,采用Energyplus软件对西安地区某公寓室内空气温度、平均辐射温度进行了模拟研究。结果表明,与无夜间通风相比,夜间通风时室内最高气温、最高平均辐射温度分别降低了0.32℃、0.34℃。室内空气温度、平均辐射温度随日较差的增大而降低,且机械通风时段比渗透通风时段降低显著。当日较差为4℃、6℃、8℃、10℃、12℃时,室内处于热舒适时段的比例分别为0,16.11%,28.06%,32.01%和34.86%。     

重庆地区某建筑不同内遮阳调控策略节能效果分析

建筑内遮阳,可以降低室内平均温度,遮挡太阳辐射,降低室内空调能耗。只有研究不同内遮阳方式和不同控制策略下的节能效果,才能更好地选择遮阳产品和控制遮光角度。该文采用金属百叶帘、布艺帘和卷帘三类内遮阳产品,选取九种不同遮阳调控策略,通过测量室内外逐时温度、墙内外壁逐时温度、玻璃内外壁逐时温度等,计算逐时温差,研究内遮阳对室内热环境变化的影响。通过比较计算,得出布艺帘全闭和卷帘全闭是最优的遮阳策略,全天平均温差高达1℃左右;布艺帘全闭策略节能率最高,达到11.3%,卷帘全闭策略次之,而百叶90°节能率最低,仅有3.6%。     

地板辐射供冷室内热环境改善研究

在地板辐射供冷中,室内空气温度常出现较大的竖直温差,使人产生头热脚冷的不舒适感。为改善地板辐射供冷中竖直温度分布不均匀的状况,采用吊扇通风和风机盘管侧吹通风来优化气流组织,改善室内温度场及舒适度。实验结果表明:与无通风相比,有通风时室内竖直温差由5℃左右降到1℃以下,显著改善了室内空气竖直温度分布不均匀的现象;供水流量与温度相同时,与无通风和风机盘管侧吹通风相比,吊扇通风时地板温度最高、空气温度最低、竖直温差最小,室内热环境最舒适,环境质量改善显著。     

分时分区毛细管辐射供暖模式下农村建筑室内热环境与能耗研究

针对北京一典型农村合院建筑,采用TRNSYS对其采用毛细管辐射分时分区供暖模式时的室内热环境与建筑能耗进行了研究。结果表明,采用毛细管辐射供暖时,停止与恢复供暖后房间温度变化较快。在最冷日采用分时分区供暖模式时,停止供暖后房间温度最低降至约12℃。综合全年统计,采用分时分区供暖模式各房间有人活动的时段温度达标率仍能保持90%以上,建筑全年总能耗可降低约8.83%。     

严寒地区教学空间夏季热舒适分析及改善策略

受全球变暖影响,哈尔滨虽地处严寒地区但近年夏季气温不断升高,导致教室热环境不再利于学生身心健康及学习效率,为改善教室热环境,文章综合分析了哈尔滨某一教室夏季室内热环境,结果发现:(1)教室热环境分布不均匀:靠窗区受太阳直射温度最高(30.6℃),与靠门区最大温差可达0.7℃;(2)教室人员热感觉分布不均匀:靠窗区热感觉最高(MTSV=2.6),靠门区最低(MTSV=1.8)。针对此现象,文章提出热环境改善策略:(1)设置可调式外遮阳构件;(3)夏季适当配合课间自然通风;(3)合理规划室内工作区位置。     

Indoor thermal environmental conditions near glazed facades with shading devices – Part I: Experiments and building thermal model

This paper presents an experimental study of indoor thermal environment near a full-scale glass facade with different types of shading devices under varying climatic conditions in winter. Interior glazing and shading temperature, operative temperature and radiant temperature asymmetry were measured for façade sections with roller shades and venetian blinds at different positions. Interior glass surface temperatures can be high during sunny days with low outdoor temperature. Shading systems significantly improved operative temperature and radiant temperature asymmetry during cold sunny days, depending on their properties and tilt angle. During cloudy days the impact was smaller, however the shading layers could still decrease the amount of heat loss through the façade. A transient building thermal model, which also calculates indoor environmental indices under the presence of solar radiation, was developed and compared with the experimental measurements. Part II of this paper uses this validated model with a transient, two-node thermal comfort model (including transmitted solar radiation) for assessment of indoor environmental conditions with different building envelope and shading properties, façade location and orientation.     

Indoor thermal environmental conditions near glazed facades with shading devices – Part II: Thermal comfort simulation and impact of glazing and shading properties

This second part of the study uses a validated dynamic building thermal model for perimeter zones with glass facades (described in Part I) and combines it with a transient two-node thermal comfort model. The objective is to investigate the impact of varying exterior climatic conditions, glazing properties and shading properties on indoor thermal comfort and heating demand in such spaces under the presence of transmitted solar radiation. It is evident that selecting appropriate fenestration components becomes a trade-off between energy, thermal comfort, and lighting needs. Facades with insulating and low transmittance glass create more comfortable and stable conditions; however, there is a relationship between lower transmittance of the glazing and increased demand of primary heating needed, as well as with lighting energy use. Regardless of glazing type, shading can improve comfort conditions by decreasing radiant temperature asymmetry and extremes in operative temperature. The results show that perimeter building zones with high-performance facades (glazing and shading) can maintain comfortable conditions and even eliminate the need for secondary perimeter heating in cold climates.     

哈尔滨地区既有住宅冬季室内热环境研究及其优化设计

2013年对哈尔滨地区部分既有住宅室内温度测试发现:典型起居室室内平均温度16.2℃,点测90%室内不足18℃;遂采用正交实验法和全因素实验法对哈尔滨地区既有住宅就围护结构及采暖方式进行优化。对比Fluent模拟结果发现,当使用壁挂式采暖器时,采暖温度起主要影响作用,以EPS保温板为例:370 mm外墙选用90 mm厚保温层、PVC三玻窗、采暖器表面温度65℃。当采用表面温度23℃低温辐射供暖时,保温层对其影响较大,370 mm外墙选用100 mm厚保温层、20 mm双玻塑钢窗,当墙体厚度为490 mm时将保温层减少5 mm。     

Measured radiant thermal fields in industrial spaces served by high intensity infrared heater

Work stations in industrial spaces are frequently arranged at a significant distance from each other. Local heating applying, among others, the gas-fired direct radiant heaters, is a viable alternative to the central heating. Radiant heaters provide heat comfort to workers and guarantee the maintenance of higher temperatures of the surrounding walls at a lower indoor temperature. The advantage of heating by gas-fired radiant heaters is the lower operational cost comparing to another systems. It uses less energy to obtain 2-3 K lower indoor temperature than in case of heating by conventional systems.The radiant temperature at work stations should be high enough to eliminate thermal discomfort, which in particular, is a result of radiant temperature asymmetry that may be caused by excessive and asymmetric overheating of the human body by a radiant heater.This paper includes formulas, based on the results of the self-designed test, which are then used in the calculation of the radiant temperature and the radiant temperature asymmetry, depending on the radiant heater position and the indoor temperature.This paper presents also the most recognized interrelations between the radiant temperature and its asymmetry. The discussed parameters are particularly significant in the heating process using high-temperature radiant heaters.     

住宅节能改造中外遮阳形式对热工性能的影响分析

根据成都地区气候特点,以减少夏季室内辐射热、同时保证冬季室内日照为目标,以一典型既有住宅户型为对象,以Ecotect环境设计分析软件建立一简化模型,对水平矩形遮阳、带有竖向构件的综合遮阳、活动百叶遮阳三种外遮阳方式做仿真模拟及计算分析,优选出热工综合性能最佳的改造方案。     

Facade design optimization for naturally ventilated residential buildings in Singapore

Parametric studies of facade designs for naturally ventilated residential buildings in Singapore were carried out to optimize facade designs for better indoor thermal comfort and energy saving. Two criteria regarding indoor thermal comfort for naturally ventilated residential buildings are used in this study. To avoid the perception of thermal asymmetry, temperature difference between mean radiant temperature and indoor ambient air temperature should be less than 2 °C [F.A. Chrenko, Heated ceilings and comfort. J. Inst. Heat. Ventilating Eng. 20 (1953) 375–396; F.A. Chrenko, Heated ceilings and comfort. J. Inst. Heat. Ventilating Eng. 21 (1953) 145–154]. Thermal comfort regression model for naturally ventilated residential buildings in Singapore was used to evaluate various facade designs either. Facade design parameters: U-values, orientations, WWR (window to wall ratio) and shading device lengths are considered in the investigation. The building simulation results for a typical residential building in Singapore indicated that the U-value of facade materials for north and south orientations should be less than 2.5 W/m² K and the U-value of facade materials for north and south orientations should be less than 2 W/m² K. From the coupled simulation results, it was found that the optimum window to wall ratio is equal to 0.24. Optimum facade designs and thermal comfort indexes are summarized for naturally ventilated residential buildings in Singapore.     

寒冷地区居室热舒适设计温度的研究

根据寒冷地区人类居住特点,利用VB语言编程,以ISO7730为理论依据,通过PMV和PPD模拟计算了寒冷地区室内热环境,给出了寒冷地区人体不同代谢率条件下常规采暖和地板辐射采暖的舒适性温度。结果表明,在PPD≤20%的前提下,寒冷地区满足人体热舒适的室内常规采暖设计温度推荐值为20℃,地板辐射采暖设计温度推荐值为19℃,明显高于我国现行的设计温度。     

地板辐射与置换通风空调系统运行参数

建立了基于EnergyPlus的地板辐射供冷加置换通风空调系统模型,模拟得到的室内温度和辐射地板所承担冷量与实验结果的误差小于±7%。在此模型基础上,改变送风参数和供水参数,得到置换通风供冷量、辐射地板供冷量、地板表面温度、室内空气平均温度、AUST温度等参数的变化规律。结合热舒适性模型,得到满足室内热舒适性(-0.5≤PMV≤0.5)条件下,置换通风的送风参数和辐射地板的供水参数范围,为复合系统设计和应用提供依据。     

上海地区双层垂直绿化办公建筑实测研究

本文通过实测,研究了夏季工况下双层垂直绿化对上海地区办公建筑热工环境的影响。实验结果表明,带有双层垂直绿化的办公室室内空气温度较普通房间平均降低了1.5℃,外墙外表面温度平均降低了1.3℃,双层垂直绿化可以有效改善上海地区办公建筑夏季热环境。本文通过实测探索了双层垂直绿化应用于办公建筑的节能潜力,并对双层垂直绿化植被选择、种植方式给出建议。