| Under the double pressure of energy and the environment, Governments around the world pay more and more attention to the development and utilization of clean and renewable energy. Undoubtedly, solar energy is a typical representative of clean and renewable energy, with the advantages of rich resources and clean pollution-free. And solar power technology has got extensive development and application. But at the same time, solar energy is intermittent and unstable by the influence of external environment, in this connection, a hybrid generation system combined photovoltaic (PV) and solid oxide fuel cell (SOFC) is designed in this paper. SOFC is a high temperature and zero emissions battery. The distributed combined cooling heating and power (DCCHP) hybrid generation has a much higher efficiency by making use of high temperature exhaust gas of SOFC. It has a great significance to ease the energy crisis and environmental pollution.Up to now, the technology of PV/SOFC hybrid generation system is immature in our country and so does the DCCHP technology. In comparison, the foreign relative research is advance. A further study of relevant literature both at home and abroad is studied deeply and a DCCHP system based on PV/SOFC is proposed in this paper.The system designed in this paper mainly includes photovoltaic array, solid oxide fuel cell, lithium-bromide absorption chiller, heat exchanger, electrolytic cell, activated carbon hydrogen storage, power conversion device, etc. The working principle of hybrid generation system is as follow:electric power is provided by the photovoltaic array and solid oxide fuel cell according to certain control law. Heat quantity is provided by heat exchanger taking use of high temperature exhaust gas of solid oxide fuel cells. Cooling quantity is provided by lithium-bromide absorption chiller using the high temperature flue gas at export side of heat exchanger. One part of the energy generated by photovoltaic array is used for user power supply, and the other part is used for electrolytic cell to produce hydrogen which is used as fuel for solid oxide fuel cell. Finally, the energy control method of whole system is proposed which mainly includes the island operation and parallel operation and realizes the cooling heating and power triple co-generation.The main works of this paper are shown as follows:The working principle of DCCHP system based on PV/SOFC is studied intensively and a system overall structure is proposed according to certain design principles and design basis; Dynamic simulink models of photovoltaic cell, solid oxide fuel cell, lithium-bromide absorption chiller, electrolytic cell and activated carbon hydrogen tanks are established and corresponding performance is analyzed; The SOFC model is integrated by power model and thermodynamic model, and the lithium-bromide absorption chiller model is the double effect of parallel process steam model; The power control device system is instituted, including the maximum power point tracking (MPPT) strategy of PV and the power conversion device; MPPT of PV is realized by three different methods which are analyzed in comparison; The rectifier unit and the inverter for 220V/50Hz is designed; The energy control strategy of whole system is proposed and analyzed in detail, including island operation and parallel operation. |
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