种植屋面热工参数

针对建筑节能工程应用的需要,研究了种植屋面节能设计热工参数,包括种植土导热系数和植被层附加热阻。采用实验方法测量了6种种植土试样材料在不同湿度下的导热系数,回归分析得到了由干密度和重量湿度确定的种植土导热系数计算式,提出了2类常用种植土的导热系数参考值:改良土为0.51 W/(m·K),无机复合种植土为0.25 W/(m·K)。采用现场测量与模拟分析相结合的方法,研究了种植屋面当量热阻与热流的关系,针对不同的植物覆盖状态,提出植被层附加热阻参考值为0.3~0.5m~2·K/W。     

南海岛礁地区种植屋面适应性浅析

结合南海岛礁地区的环境气候特性分析平屋顶简单式种植屋面、平屋顶花园式种植屋面、平屋顶蓄水种植屋面、坡屋顶种植屋面和容器式种植屋面的技术特点和经济成本,为在我国南海岛礁地区开展种植屋面应用提供参考。     

夏热冬暖地区屋顶隔热构造措施探讨

根据夏热冬暖地区气候的特点,介绍分析了适合该地区气候条件的被动蒸发隔热屋面、种植屋面、反射阳光隔热屋面三种屋面的隔热构造技术措施,并对这几种屋面的隔热效果进行了比较。     

种植屋面的构造与层次

根据不同地区的气候特点（气温和降雨），分别提出种植屋面的设计构造，对地下室顶板上作种植及种植屋面各层次所用材料也作了介绍。     

夏热冬暖地区屋顶隔热构造措施探讨

根据夏热冬暖地区气候的特点，介绍分析了适合该地区气候条件的被动蒸发隔热屋面、种植屋面、反射阳光隔热屋面三种屋面的隔热构造技术措施，并对这几种屋面的隔热效果进行了比较。     

建筑用隔热涂料热工性能评价方法分析

外墙及屋面通过采用热反射隔热涂料来提高太阳光反射比和半球发射率,从而达到了隔热降温效果,结合上海的气候特点对此进行了理论分析。参考国内外隔热涂料相关标准,提出了涂层稳态表面温度、等效热阻、热惰性修正系数等评价指标及方法,为隔热涂料的效果评价提供了理论依据。     

茂名地区住宅屋面节能设计

建筑物的屋面是外围护结构中受室外热作用影响最大的部位.文中根据茂名地区气候的特点及住宅建筑可推行的条件,分析了适合该地区气候条件的大阶砖通风屋面、阁楼通风屋面、种植屋面等三种屋面的隔热构造技术措施,并对这三种屋面的隔热效果进行了比较.     

种植屋面构造层研究

由于地域气候等条件的不同,各地种植屋面的构造做法也不尽相同。在此,论述种植屋面特点及其常见类型,并以典型工程为例,提出了四种类型种植屋面构造做法。探讨了保温层的设置原则、层次及适用材料,以及防根系穿刺防水层或替代层的设置方法等。     

倒置式屋面防水找平层的施工优化

随着具有吸湿性低、压缩强度高、耐气候性强、热阻率高、有憎水特性的新型保温材料出现(如聚苯乙烯泡沫塑料板或聚氨酯泡沫塑料板),使得倒置式屋面做法从技术层面上成为可能,目前倒置式屋面在实际工程中已得到普遍应用.     

郑州地区种植屋面不必设计防冻胀层

介绍种植屋面的组成,分析了气温、土壤水分及土壤组分等冻土产生膨胀力的3个条件,并结合郑州地区的气候特征,认为郑州地区的种植屋面不必设计防冻胀层.     

Study on evaporative cooling effect of roof lawn gardens

In a very hot climate equivalent to a Japanese summer, the reduction of heat coming into rooms is very important with respect to thermal comfort and energy efficiency. The objective of this study is to investigate the evaporative cooling effect from roof lawn gardens planted in non-woven fabric as one mode of passive cooling. It was confirmed by field measurements during the summer that the amount of heat coming into the rooms was reduced by a roof lawn garden. That is, the surface temperature of the roof slab decreased from about 60 to 30°C during day time, which was estimated to be followed by a 50% reduction in heat flux into the room by simple calculation. The evaporative cooling effect from roof lawn gardens is considered to play an important role in reducing heat flux. In order to evaluate the evaporative cooling effect of a roof lawn garden, analysis of the heat and moisture transport in the lawn garden is required. Thus, along with those field measurement, a wind tunnel experiment in a room was carried out in order to obtain the basic information for understanding and predicting the heat and moisture transport in the lawn. Furthermore, a numerical calculation by a simultaneous transport model of heat and moisture was carried out using the results of the wind tunnel experiment. The calculated results were in fairly good agreement with the measured values, and the evaporative cooling effect by the roof lawn garden was shown. For more accurate and quantitative evaluation and prediction, sensitivity analysis of the transport parameters and the examination of the proposed model including measurements are required.     

某住宅楼保温种植屋面改造设计及实测数据分析

以不采暖住宅楼保温种植屋面设计改造工程为例,论述了其构造层次的可行性。通过计算该屋面构造方案的总热阻值及传热系数等,确定该方案满足国家现行规范要求的节能标准。分析对比了该种植屋面改造前后冬季最冷月四天的室内外实测数据,验证了保温种植屋面改造方案的保温效果。     

室内气温对绿化屋顶当量热阻的影响

绿化屋顶在节能设计中以附加当量热阻增大屋顶总热阻值,有效减少由屋顶进入室内的热量,降低室内空气温度。但根据已有的实验研究,绿化屋顶隔热特性与室内气温是耦合关系,随室内气温的变化,绿化屋顶会呈现出不同的隔热特性。用实验测试与数值模拟相结合的方法,分析在不同室内气温下绿化屋顶、参照屋顶与等效保温屋顶内表面温度与热流的变化。结果表明:室内气温会显著改变绿化屋顶的隔热性能,其当量热阻为与室内温度正相关的变量。在被动式建筑中,绿化屋顶更能充分发挥隔热功效,且具有不向室内传热的特性。     

基于屋顶绿化热工性能研究节能降温效应

随着建筑能耗比例持续增高,屋顶绿化作为节能设计重点技术之一,具有巨大的节能潜力。通过屋顶绿化的构造及各层参数来分析屋顶绿化的隔热原理,并结合外表面温度、内表面温度和当量热阻3个影响因素阐释屋顶绿化对室内空调能耗的影响。以杭州市某住宅项目为研究对象,运用PHOENICS软件模拟整个住区环境的建筑实况,验证有无屋顶绿化时室内温度差值,来证明屋顶绿化确实减少室内空调运行能耗,一定程度上缓解周围热岛,为夏热冬冷地区隔热节能设计提供理论基础。     

Thermal analysis of vaulted roofs

In hot arid regions, cooling buildings by passive techniques is very important regarding energy saving and the need to keep clean the environment. In such areas, domed and vaulted roofs are widely used for centuries, such as in the Middle East region and central part of Iran. In this article analysis is made to explore east–west direction of wind flow around north–south vaulted roofs and flat roof buildings. Combined convection and solar radiation over the roofs is considered to studying thermal performances of vaulted roofs and comparing their heat transfer with flat roofs. Two-dimensional RNG k–? turbulence model is incorporated to predict turbulent flow field as well as separation and recirculating patterns around the vaulted roofs and flat roof buildings. Solar radiation distribution over the roofs is determined based on an appropriate model applicable to hot arid regions of Iran. Pressure differences above the vaulted roof are compared with flat roof for various rim angles and different wind speeds. Heat transfer to the building with respect to time is determined for a certain inside ceiling design temperature, various wind flows and vault shapes, and results are compared with corresponding flat roof. It was found that daily average heat flux for all vaulted roofs, except vaulted roof of rim angle 180° is less than flat roof and it reduces further by increasing wind speed.     

秦皇岛体育场膜结构挑篷的抗风分析与设计

结合秦皇岛体育场膜结构挑篷的风洞试验研究,以挑篷上的典型膜面的风荷载特性和风荷载响应为研究对象,直接采用风洞试验测量所得到的风荷载数据,对膜面进行了详尽的静力风荷载响应分析和非线性风振响应分析;试验结果分析表明,挑篷前缘膜面的负压风荷载数值最大,是膜结构挑篷设计的控制荷载。非线性分析表明,通过设置抗风索可以有效提高膜结构的抗风性能;膜面的风振动力效应并不显著,可以近似采用阵风系数来考虑脉动风的瞬时增压作用。这些结果可为类似结构的抗风设计提供参考。     

隧道仰拱及基底能量桩热致应力与换热效率现场试验

依托黄土塬区银川—西安高铁驿马一号隧道工程,在隧道仰拱和基底桩基内埋设换热管,搭建能源隧道仰拱-基底能量桩联合热泵系统,实测不同进口温度作用下换热管的进出口水温、隧道仰拱结构和基底桩基的温度、热致应力,探讨黄土塬区隧道仰拱结构及基底桩基的换热效率、热力响应特性与变化规律。结果表明:在现场特定条件下,进口温度与初始地温差值分别为4.7 ℃和14.7 ℃时,隧道仰拱结构温度升幅分别约为3.8 ℃和11.4 ℃,热致轴向应力分别为3.13 MPa和13.86 MPa,热致环向应力分别为2.85 MPa和9.93 MPa,隧道仰拱换热效率分别约为7.86 W?m^-1和24.15 W?m^-1; 单位温升条件下热致轴向应力和热致环向应力分别为0.44 MPa?℃^-1和0.35 MPa?℃^-1; 恒功率运行下仰拱基底能量桩换热效率随进口温度与初始地温差值的变化近乎为一条斜率k=4.1过原点的直线,换热效率维持在50～70 W?m^-1之间,与常规能量桩的换热效率规律基本一致; 桩基周围土体的力学性质受能量桩运行影响有限。     

Behavior of a mechanically anchored waterproofing membrane system under wind suction and uniform Pressure

A pressure and wind tunnel test was conducted to obtain the basic data for wind resistance design of a mechanically anchored waterproofing membrane system. The test specimen was a flat roof with the following dimensions: 2.4 m in width, 3 m in length and 0.29 m in height. The waterproofing material was polyvinyl chloride sheet reinforced with polyester fiber (PVC sheets). In the pressure test, because the applied pressure was equivalent to the pressure on the entire surface area of the roof, the billowing heights of the PVC sheet around the fastener had almost the same maximum values; therefore, the axial force at the fastener was also similar to the pressure induced by a compressor, and no lateral forces were measured. On the other hand, in the wind tunnel test, the strain of the PVC sheet around the fastener at windward side was larger than that of the leeward side. The lateral force was 70% of the axial force at a mean wind speed of 38.6 m/s. Therefore, it was clear that the characteristics of the mechanically anchored waterproofing membrane system in the pressure test and the wind tunnel test were different.     

Smoke spreading characteristics during a fire in a shallow urban road tunnel with roof openings under a longitudinal external wind blowing

A series of fire experiments was conducted using a 1:12 scale model of a shallow urban road tunnel with roof openings to clarify the flow structure of smoke and fresh air during a fire with a longitudinal external wind blowing above the roof openings. The model tunnel consisted of two road tubes separated by a pillar-type median structure. Five fire test cases were conducted by changing the heat release rate as the experimental parameter. When the smoke produced by a fire in the tunnel tube was exhausted by natural ventilation through the roof openings of the tunnel tube, fresh air was sucked in from the roof openings of the opposite tunnel tube. The flow of exhausted smoke and sucked-in fresh air created a complex three-dimensional flow structure inside the tunnel tubes. Stratified smoke that had formed under the ceiling of the tunnel tube was disturbed by the flow of sucked-in fresh air and was diffused on the upstream side of the fire. Compared to the condition without a longitudinal external wind, when a longitudinal external wind blew over the tunnel with the pillar median structure, the smoke spreading distance on the upstream side was longer than that without the external wind due to the diffusion of smoke. On the other hand, the smoke spreading distance on the downstream side of the fire was shorter than that without the external wind due to the improved smoke extraction performance by the Venturi effect of the longitudinal external wind. Furthermore, the smoke spreading distance on the downstream side was nearly constant and independent of the heat release rate of the fire, within the scope of our experimental conditions.     

串/并联运行下能源管廊相对热效率及热致应力现场试验

依托南京雨花台区软件谷杆线迁移地下综合管廊工程,在管廊的底板、侧板及顶板内埋设换热管形成能源管廊,并通过恒定输入功率加热循环液体,对明挖施工能源管廊的换热规律进行现场试验; 实测能源管廊的换热系统进/出口水温、底板温度及热致应力等变化规律,初步探讨并联和串联的能源管廊段连接形式下,系统运行过程中的相对热效率及热致应力响应性能,以及能源管廊段运行过程中对周围管廊段结构造成的影响。结果表明:试验条件下并联和串联运行下能源管廊的相对线热效率分别为39.68、31.27 kW?m^-1,并联较串联运行模式提高了约26.9%,即并联运行的换热性能相对较好; 并联和串联运行过程中底板产生的最大轴向热致应力分别为1.30、1.24 MPa(两者相差小于10%),由于叠加效应,邻近管廊段产生0.33 MPa的最大压应力,对地下综合管廊结构安全性的影响较小; 相关结论可为依托城市地下综合管廊开展能源管廊或隧道的设计和计算提供参考。