Primerjava in ovrednotenje izotropnega in anizotropnega modela sončnega obsevanja

Mekuč, Miha (author), Prek, Matjaž (mentor), Butala, Vincenc (comentor)

Za dimenzioniranje solarnih naprav in preračunavanje rabe energije v stavbah potrebujemo podatke o jakostih sevanja in obsevanja različno nagnjenih in usmerjenih ploskev. Izmerjeni podatki so na razpolago samo za vodoravne ploskve. Za drugače nagnjene in usmerjene ploskve moramo podatke preračunati. Raziskovalci so razvili več modelov, ki se v grobem ločijo na izotropne in anizotropne. Najbolj popularna modela sta Liu-Jordanov med izotropnimi in Perezov med anizotropnimi. V zadnjem času anizotropni modeli zamenjujejo izotropne modele. V tem delu je izvedena primerjava izračunanih in izmerjenih vrednosti za različno nagnjene in usmerjene ploskve. S primerjavo izračunanih vrednosti po več modelih in izmerjenih vrednosti je ovrednoten in potrjen smisel prehoda in izboljšanje zaradi prehoda na Perezov anizotropni model. Preračunan je tudi vpliv zamenjave modela na prestop sevanja skozi zastekljeno okno. Ugotovljeno in pokazano je, da Perezov anizotropni model daje bolj zanesljive in tehnično uporabne rezultate. Kot praktični primer je izveden preračun sončnega sevanja za zimski vrt, ki bo zgrajen na južni strani stanovanjske stavbe.

• Language: Slovenian
• Keywords: sevanje, obsevanje, sončno, model, izotropni, anizotropni, okno
• Work type: Master's thesis/paper
• Organization: FS - Faculty of Mechanical Engineering
• Year: 2017
• PID: 20.500.12556/RUL-94858
• Publication date in RUL: 08.09.2017

Secondary language

• Language: English
• Title: Isotropic and anisotropic solar model comparison and evaluation

Abstract

To design solar equipment and calculate energy performance of buildings solar radiation and irradiation to inclined and diferent oriented surfaces are needed. Measured data exist for horizontal surfaces only. For inclined and diferent oriented surfaces values have to be calculated. Researchers developed many models, which can be divided into two groups: isotropic and anisotropic. Most popular isotropic and anisotropic model are Liu-Jordan and Perez respectively. In several times isotropic models are replaced by anisotropic. In this work calculations and measurements for vertical and inclined surfaces with different orientations were compared. Sense and improvement of calculations due to change to Perez anisotropic model are evaluated with comparison of with some models calculated and measured data. It is confirmed, that change to Perez anisotropic model is reasonable. Transmission of radiation through the glass window was recalculated too to evaluate model change impact. It is found out that, Perez anisotropic model gives more reliable and technical usefull results. As real example, impact of solar radiation on energy performance of greenhouse built at south side of dwelling house, is evaluated.

• Keywords: radiation, irradiation, solar, model, isotropic, anisotropic, window