TRNSYS MODELING OF A HYBRID LIGHTING SYSTEM: BUILDING ENERGY LOADS AND CHROMATICITY ANALYSIS

摘要

The TRNSYS program provides algorithms to calculate the beam and diffuse radiation on any surface as a function of time based on horizontal radiation measurements. However, no methods are currently provided in TRNSYS to determine the spectral distribution of solar radiation. This paper describes the inclusion of a spectral model in TRNSYS. The model uses Gueymard's SMARTS2 (Simple Model of the Atmospheric Radiative Transfer of Sunshine) algorithm to calculate the spectral power density of sunlight as a function of solar position, atmospheric turbidity, moisture content, and other atmospheric parameters. The inclusion of the spectral model was necessary to perform building illumination and energy load analyses on a 2500 m~2 office building equipped with a hybrid lighting system (HLS). The HLS uses two-axis tracking collectors to collect beam normal radiation that is later divided into visible and infrared components. The visible radiation is piped to luminaires inside the building using optical fibers, while the infrared radiation is focused on thermal photovoltaic arrays and used to generate electricity. The TRNSYS model was used to calculate annual building energy loads (lighting, cooling, and heating) and illumination chromaticiry values (correlated color temperature and color rendering index) for office buildings in Tucson, AZ and Seattle, WA. These locations were selected to exemplify best and worst case results, respectively. Annual energy savings and chromaticity values for office buildings located in these cities are presented.