태양열 계간축열 시스템 적용에 의한 시설원예 난방의 에너지 절감 효과 분석

Abstract

Seasonal thermal energy storage (STES) is widely researched because it utilizes excess energy that would be wasted otherwise. The purpose of this study is to analyze the energy efficiency of seasonal solar thermal energy systems as heating systems for greenhouses and to compare it with conventional variable air volume (VAV) heating systems. A greenhouse was chosen as a simulation model, because it requires constant and stable heating through the winter to extend the growing season and also because greenhouses can provide enough area to install solar collectors and heat storage tanks. When STES is used in greenhouse buildings to control the temperature, it is expected to perform at its full capacity, because greenhouses only need heating, and a large amount of heating is needed. The proposed seasonal solar thermal energy storage system consists of a solar thermal collector, fully mixed heat storage tank, and VAV heating system. Energy simulation was conducted in two steps: heat storing throughout the year and heating in the winter. 125 greenhouses with area of 32 m2 each, 125 solar thermal collectors of 10 m2 each, and heat storage tank of 2000 m3 was designed. TRNSYS 18 and an engineering equation solver were implemented for simulation and calculation of the system’s thermal data. Simulation results showed STES heating contributing to 29% of the total heating load.