I Am calculating the temperature rise in optical lens due to solar radiation in CPV system and I need the energy generated by radiation per volume unit, I need that because the lens is considered somehow thick 88mm, how I can calculate energy or heat generated in Concentrating lens under solar irradiance condition?
If you know, from the lens factory or from measurement, the absorption coefficient for solar radiation of your lens material, the heat released in the lens is simply the product of the solar irradiation on the lens (i.e the lens arrea multiplied by the irradiance in W/m²) by the absorption coefficient.
Thank you so much for your answer, in this case the material used is BK7 glass, based on this I only have to multiply the aperture area of the lens with the absorption coefficient with the radiation value. but will this take into consideration the depth of the glass and the change in temperature throughout the lens? and is there any reference or article you advice of reading it about this matter ?
If you have the absorption coefficient of the BK7 material (see second attached link) and not that of the lens itself, you should first calculate the absorption coefficient of the whole lens. See the attached document (word and pdf formats).
The temperature may have an effect if the absorption coefficient changes with the temperature. Unfortunately, I did'nt found any information on the variation of the absorption coefficient with temperature in BK7 glass. In fused silica, it approximately doubles between 500 K and 1000 K (see first attached link).
http://refractiveindex.info/?shelf=glass&book=BK7&page=SCHOTT
Article 3D Finite Element Model for Writing Long-Period Fiber Gratin...
- Badges
- Science topic