...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Building and Environment >Enhancement of natural ventilation rate and attic heat gain reduction of roof solar collector using radiant barrier
【24h】

Enhancement of natural ventilation rate and attic heat gain reduction of roof solar collector using radiant barrier

机译：使用辐射屏障提高屋顶通风器的自然通风率并减少阁楼热量获取

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Presented in this paper are the experimental results on natural ventilation flow rate enhancement and attic heat gain reduction of a roof solar collector equipped with a radiant barrier (RB). Investigation was conducted using an open ended inclined rectangular channel with an RB. The RB was used on the lower plate while the upper plate was heated with constant heat flux intensity. The channel dimensions are 1.5 x 0.70 x 0.19m. The slope of the channel was fixed at 30° from horizontal plane. Four heat flux (190.5, 285.7, 380.9 and 476.2 W m~(-2)) and five air gap space (3, 5, 7, 9 and 11 cm) were considered. Data analysis was made to determine the free convection heat transfer coefficient and induced airflow rate using two dimensionless parameters, viz., Nusselt number (Nu) and Reynolds number (Re). The Nu and Re were correlated as a function of Ra sin 30 and channel aspect ratio defined as the ratio of air gap space to the channel length. The relations obtained were as follows: Nu = 0.371(Ra sin 30)~(0.2223) (S/L)~(0.0469) and Re = 191.68(Ra sin 30)~(0.1213)(S/L)~(-0.085). When compared to a conventional roof solar configuration with gypsum board on the lower part, it was observed that the use of RB increased convective heat transfer and airflow rate by about 40-50%, thereby increasing heat transfer reduction through the lower plate by about 50%. The developed correlations are useful for the design of such open-ended channels like the roof solar collector for passive ventilation of houses.
机译：本文介绍的是安装有辐射屏障（RB）的屋顶太阳能集热器的自然通风流量增加和阁楼热增益降低的实验结果。使用带有RB的开放式倾斜矩形通道进行研究。 RB用于下板上，同时以恒定的热通量强度加热上板。通道尺寸为1.5 x 0.70 x 0.19m。通道的坡度固定为与水平面成30°。考虑了四个热通量（190.5、285.7、380.9和476.2 W m〜（-2））和五个气隙空间（3、5、7、9和11 cm）。使用两个无因次参数，即Nusselt数（Nu）和Reynolds数（Re），进行数据分析，以确定自由对流换热系数和诱导气流速率。将Nu和Re作为Ra sin 30的函数和定义为气隙空间与通道长度之比的通道长宽比相关。得到的关系如下：Nu = 0.371（Ra sin 30）〜（0.2223）（S / L）〜（0.0469）和Re = 191.68（Ra sin 30）〜（0.1213）（S / L）〜（-0.085） ）。与下部带有石膏板的传统屋顶太阳能配置相比，观察到，使用RB可提高对流传热和气流速率约40-50％，从而将通过下板的传热减少量提高约50％。 ％。所建立的相关性对于此类开放式通道的设计很有用，例如用于房屋被动通风的屋顶太阳能收集器。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号