کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1551414 998131 2010 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Daylight illuminance on horizontal and vertical surfaces for clear skies. Case study of shaded surfaces
موضوعات مرتبط
مهندسی و علوم پایه مهندسی انرژی انرژی های تجدید پذیر، توسعه پایدار و محیط زیست
پیش نمایش صفحه اول مقاله
Daylight illuminance on horizontal and vertical surfaces for clear skies. Case study of shaded surfaces
چکیده انگلیسی

This paper presents the results of a study on daylight illuminance levels measured on horizontal and vertical surfaces. Firstly, an attempt to know the behavior of the daylight illumination in a specific area, as the ‘Castilla-Leon’ region, Spain, is made in order to determine the representative values of this parameter in this geographical area. With this aim, a series of measurements of global illuminance on a horizontal surface and on vertical surfaces oriented to the four cardinal points (N, S, E and W) have been collected and analyzed. In the paper, the daily evolution of this parameter is reported considering different times of the year so that a global annual behavior can be established. The study is focused on clear days. The collected data correspond to 10 min measurements carried out during the year 2007 in a rural area close to the city of Valladolid, Spain, in the mentioned region. In addition to that, the data have been treated in order to analyze the relationship between the global vertical illuminance and the corresponding horizontal illuminance. In case that no direct sunlight is reaching a vertical surface, that is, for a shaded surface, a simple parametric equation is proposed in order to predict the vertical illumination. The expression obtained shows a high correlation coefficient. It relates the ratio between vertical and horizontal illuminances versus the solar altitude; so, it permits to calculate vertical illuminance if horizontal illuminance is known.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Solar Energy - Volume 84, Issue 1, January 2010, Pages 137–143
نویسندگان
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