A solar-heat-driven ejector-assisted combined compression cooling system for multistory building - Application potential and effects of floor numbers

Solar-powered hybrid ejection-compression refrigeration system is an important energy-saving technology in space cooling. However, the system is barely reported to be used in multi-storey building and its application in multi-storey building is limited in crowed city, as it requires large area of solar collector because of low thermal efficiency. To fill this research gap, a solar-heat-driven ejector-assisted combined compression (SECC) cycle specially designed for multistory buildings is investigated in this paper. Based on SECC, a cooling system for a 5-storey office building located in Shanghai is designed, optimized and also compared to conventional ejection compression refrigeration cycle (CEC). The overall cooling system using SECC can reduce 203.17 MJ (11.8%) electricity than the cooling system based on CEC, in one day. The effects of building height on system performance is also reported which is seldom found in published references. The cooling system with SECC always consumes less electric energy than the one with CEC, when the building height is larger than 2 floors. It has a best improvement of 21.2% at 3-floor height and has 11.1% good improvement even at 15-floor height, comparing with vapor compression cycle. The results show that SECC has important advantage and is particularly suitable for multi-storey building.