Analysis on operation characteristics of photovoltaic-driven electricity-oxygen-humidity cogeneration system for office buildings in Tibetan Plateau

In view of the low pressure, hypoxia, dry climate characteristics and the shortage of conventional energy in Tibetan Plateau, this paper proposes a photovoltaic-driven electricity-oxygen-humidity cogeneration system. Through the analysis of the energy balance process, a mathematical model of the system is established. Taking an office building in Qamdo, Tibet as an example, the annual energy flow characteristics of the system and the influence of different equipment capacities on its operating performance are analysed by numerical simulation. Finally, the system is compared with the traditional municipal power supply system. The research results show that when the roof of the case building is fully covered with photovoltaic arrays, the photovoltaic power generation can meet about 57% of the energy demand of the building. When the oxygen storage capacity of the oxygen storage tank is 3 times the daily average oxygen load, the oxygen supply rate of the oxygen storage tank increases by 18% at most. When the power of the oxygen generator increases from 10 kW to 72 kW, the oxygen supply dissatisfaction rate decreases by about 71%. Compared with the traditional municipal power supply system, the cogeneration system saves 25.4% of the net economic cost and reduces the carbon dioxide emission by 56.4%. This study can provide theoretical support for the design of photovoltaic-driven electricity-oxygen-humidity cogeneration systems in Tibetan Plateau.