梭形翻板太阳直射辐射传输计算模型及实现

Calculating Model of Solar Direct Radiation Transporting Through Shuttle Louvers and Realization

摘要:

首先，取相邻2块遮阳翻板为研究对象, 采用解析法建立直射辐射直接透过部分的计算模型，采用光线追踪法得到的反射次数和方向建立直射镜面反射部分的计算模型，采用净辐射法建立直射漫反射部分的计算模型；其次,在模型分析基础上，用MATLAB软件编制了能描述翻板形状、尺寸、倾角、表面光学特性的梭形翻板直射辐射传输计算程序；最后，分析了传统计算方法对梭形翻板进行平板假设所带来的误差，认为用“平板假设”模型的计算结果偏大，特别是在翻板开口朝向正对太阳光线入射方向时误差值最大,其余情况相对误差都在5%以上。

Abstract:

Firstly, two adjacent shuttle louvers were taken as the research object, the new model employed analytical method to analysis the fraction of beam radiation passing directly through the louvers, specular reflection fraction of beam radiation using the number and direction of reflection based on ray-tracing method, and net-radiation method was used to analysis diffuse reflection fraction. Secondly， based on the model analysis, the calculating program of solar direct radiation was developed with the MATLAB software to describe the shape, size, tilt angle and surface optical properties of shuttle louvers. Finally, the errors of the traditional calculation methods were analyzed , and found that “flat hypothesis ” model would overvalued results of solar transmission, especially when the opening is directly?facing?the incident beam radiation. And the relative error is 5% or more for the rest situation.