共查询到16条相似文献,搜索用时 281 毫秒
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建筑墙体的室内表面温度直接反映墙体的保温隔热性能,并且作为室内平均辐射温度的主要组成部分对室内热环境有重要影响。针对建筑工程中大量使用的空心砖墙体具有表面温度不均匀的特点,采用ThermaCAM P20型红外热像仪和ThermaCAM Reporter分析软件,研究应用红外热像法测量空心砖墙体的表面温度,分析空心砖墙体的温度特征以及空心砖、 砌筑砂浆、 配砖等组成材料对表面温度分布的影响。在高层住宅建筑工程现场,选择三层住宅的填充外墙位置,使用不同的烧结页岩空心砖、 砌筑砂浆和配砖砌筑成三种空心砖墙体进行传热实验。通过采集三种烧结页岩空心砖墙体在冬季室内采暖条件下的内表面温度红外热像图,对比分析了两种空心砖和两种砂浆砌筑的墙体表面温度特性数据以及温度均匀性和温度频率分布。结果表明:提高空心砖和砌筑砂浆的保温性,能够有效提高墙体内表面温度,改善室内热环境;由保温砂浆代替水泥砂浆砌筑的节能型烧结页岩空心砖墙体,表面温度的不均匀性从0.6 ℃下降为0.4 ℃,并使表面温度频率分布发生变化,从非对称分布变为正态分布;随着表面温度均匀性的提高,平均温度所占的频率增大。本研究为空心砖墙体热功能的提高和优化提供了依据。 相似文献
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唐鸣放尹轶华 《光谱学与光谱分析》2015,(5):1228-1232
建筑墙体的室内表面温度直接反映墙体的保温隔热性能,并且作为室内平均辐射温度的主要组成部分对室内热环境有重要影响。针对建筑工程中大量使用的空心砖墙体具有表面温度不均匀的特点,采用ThermaCAM P20型红外热像仪和ThermaCAM Reporter分析软件,研究应用红外热像法测量空心砖墙体的表面温度,分析空心砖墙体的温度特征以及空心砖、砌筑砂浆、配砖等组成材料对表面温度分布的影响。在高层住宅建筑工程现场,选择三层住宅的填充外墙位置,使用不同的烧结页岩空心砖、砌筑砂浆和配砖砌筑成三种空心砖墙体进行传热实验。通过采集三种烧结页岩空心砖墙体在冬季室内采暖条件下的内表面温度红外热像图,对比分析了两种空心砖和两种砂浆砌筑的墙体表面温度特性数据以及温度均匀性和温度频率分布。结果表明:提高空心砖和砌筑砂浆的保温性,能够有效提高墙体内表面温度,改善室内热环境;由保温砂浆代替水泥砂浆砌筑的节能型烧结页岩空心砖墙体,表面温度的不均匀性从0.6℃下降为0.4℃,并使表面温度频率分布发生变化,从非对称分布变为正态分布;随着表面温度均匀性的提高,平均温度所占的频率增大。本研究为空心砖墙体热功能的提高和优化提供了依据。 相似文献
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Lightweight inner leaves contribute more than heavier inner leaves to thermal insulation, but there are reasons for expecting that they may adversely affect the sound insulation of party floors. The most sensitive indicator of the influence of inner leaves is provided by differences, if any, between the performance of centre block and end block floors tested in the same block of flats. Analysis of data from all blocks where floors in both situations were tested shows that, on average, the airborne insulation of end floors is significantly poorer than that of centre floors when the party walls are heavier than the inner leaves. Impact insulation is affected to a smaller extent. The airborne insulation of end floors adjacent to plastered inner leaves of surface mass less than 120 kg/m2 is found to be significantly worse than that of end floors adjacent to heavier inner leaves.When party wall leaves are similar to inner leaves differences are not significant and the two situations may be treated as equivalent. The effect of plasterboard internal partitions is also assessed and found to be beneficial. 相似文献
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基于绝热过程(火积)耗散极值原理, 分别在对流传热和复合传热(对流和辐射传热)边界条件下, 对轧钢加热炉壁变截面绝热层进行构形优化, 得到(火积)耗散率最小的绝热层最优构形. 结果表明: 与等截面绝热层相比, (火积)耗散率最小的变截面绝热层整体绝热性能更优. 热损失率最小和(火积)耗散率最小的绝热层最优构形是不同的. 热损失率最小的绝热层最优构形使得其能量损失减小, 而(火积)耗散率最小的绝热层最优构形使得其整体绝热性能提高. (火积)耗散率最小和最大温度梯度最小的变截面绝热层最优构形差别较小, 此时(火积)耗散率最小的绝热层最优构形在提高绝热层整体绝热性能的同时也提高了其热安全性. 基于(火积)理论的绝热层构形优化为绝热系统的优化设计提供了新的指导. 相似文献
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基于变换热力学, 采用坐标斜变换和旋转变换得到定向传热结构单元的热导率分布表达式, 并利用隔热材料和铜分层排布实现了定向传热结构单元. 将定向传热结构单元周期性排列, 得到二维平板定向传热结构. 数值计算结果表明: 当外部热流流向该结构上表面时, 热量主要向两侧流动, 从而使上下表面保持低温. 与同厚度二氧化硅气凝胶隔热材料相比, 上表面温度降低33.3%, 下表面温度降低4.3%, 而侧面温度上升40.1%. 定向传热结构上表面温度的降低表明能够及时导走热量, 从而降低上表面的红外辐射; 下表面温度的降低说明定向传热结构比二氧化硅隔热材料具有更好的隔热效果; 上表面热量主要向两侧传输造成侧面温度急剧升高, 有利于热能的有效利用. 定向传热结构在红外隐身、热防护领域具有潜在的应用价值. 相似文献
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The control of sound transmission through panels is an important noise control problem in the aerospace, aeronautical, and automotive industries. The trend towards using lightweight composite materials that have lower sound insulation performance is a negative factor regarding low frequency transmission loss. Double-panel partitions with the gap filled with sound absorption materials are often employed to improve the sound insulation performance with reduced added weight penalty. However, in the low frequency range, the strong coupling between the panels through the air cavity and mechanical paths may greatly reduce the sound transmission performance, making it even lower than the performance of a single panel in some frequency ranges. In this work, an experimental investigation of a new kind of hybrid (active/passive) acoustic actuator is presented. The idea consists of replacing the acoustic absorption material by a hybrid actuator aiming at improving the transmission loss at low frequencies without altering the passive attenuation. A prototype of the system is tested in a plane wave acoustic tube setup. Different kinds of SISO feedforward control implementations were used to attenuate the sound power transmitted through the hybrid active–passive panel using an error microphone or a particle velocity sensor placed downstream with respect to the sample panel. Measurement results of the transmission loss with active and hybrid attenuation are presented and discussed. 相似文献
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基于现有冷屏结构,结合CFETR聚变堆装置的结构特点,提出了一种沿冷却板厚度方向钻冷却通道的深孔结构方案.对内冷屏各部件设计了并联加串联的特殊流道,采用有限元法计算了该方案内冷屏各部件的温度分布.结果表明,采用深孔法冷却方式,冷屏温度分布更均匀,降温效果更好.在输出辐射功率相近的条件下,深孔法的冷却方式可将表面辐射率上... 相似文献