文档介绍：外文翻译
学院: 嘉兴学院
专业: 建筑环境与设备工程
班级: 建环121
学号: 201251645123
姓名: 陈晨
指导教师: 阳季春
5
Radiation Transmission through
Glazing: Absorbed Radiation
The transmission, reflection, and absorption of solar radiation by the various parts of a solar collector are important in determining collector performance. The transmittance, reflectance, and absorptance are functions of the ing radiation, thickness, refractive index, and extinction coefficient of the material. Generally, the refractive index n and the extinction coefficient K of the cover material are functions of the wavelength of the radiation. However, in this chapter, all properties initially will be assumed to be independent of wavelength. This is an excellent assumption for glass, the mon solar collector cover material. Some cover materials have significant optical property variations with wavelength, and spectral dependence of properties is considered in Section . Incident solar radiation is unpolarized (or only slightly polarized). However, polarization considerations are important as radiation es partially polarized as it passes through collector covers.
The last sections of this chapter treat the absorption of solar radiation by collectors, collector-storage walls, and rooms on an hourly and on a monthly average basis.
Reviews of important considerations of transmission of solar radiation have been presented by Dietz (1954, 1963) and by Siegel and Howell (2002).
REFLECTION OF RADIATION
For smooth surfaces Fresnel has derived expressions for the reflection of unpolarized radiation on passing from medium 1 with a refractive index to medium 2 with refractive index :
()
()
()
where θ1 and θ2 are the angles of incidence and refraction, as shown in Figure . Equation represents the ponent of unpolarized radiation , and Equation represents the ponent of unpolarized radiation . (Parallel and perpendicular refer to the plane defined by the incident beam and the surface