시설원예 에너지자립형 계간축열기반 신재생 융복합시스템 적용성 분석

Abstract

This study investigated the energy performance of renewable energy convergence system based on the seasonal thermal energy storage for zero energy greenhouse. The proposed system was integrated with photovoltaic and solar thermal (PVT) system, solar thermal (ST) system, two types of seasonal thermal energy storages, and hybrid source heat pumps. The flat-plate type ST panel is integrated with tank type seasonal thermal energy storage (TTES) and the PVT is integrated on the borehole type seasonal thermal energy storage (BTES). The produced thermal energy through the ST system is mainly stored into the TTES. When the temperature of TTES is higher than the target temperature, the produced thermal energy from ST is stored into the inner BTES. The produced thermal energy through the PVT system, mainly stored into the outer BTES. The three types of heat pumps were used to assist the TTES and BTES. The one hybrid heat pump uses the air source and heat of TTES to produce the cooling and heating water for greenhouse. Another hybrid heat pump uses the air source and heat of BTES, and the other heat pump uses ground source. The energy performance of the proposed system was analyzed by TRNSYS software. The test site of greenhouse has 3,942 m² of total area and the proposed system serves cooling and heating energy. It was found that the proposed system showed 10.0 % of direct solar fraction and 41.2 % of total solar fraction.