Research On The Modeling And Performance Simulation For DCCHP System Based On SOFC/MGT Technology

At present, the requirement of global energy is increasing. The energy utilization efficiency of traditional ways is low, and they seriously affect the living environment of mankind. Therefore, the important development goals are developing new clean energy, finding a reasonable way to use the energy and protecting the environment. Because of the long development period and poor stability of new clean energy, increasing energy utilization is a reasonable way to alleviate the energy shortage. SOFC is a kind of efficient and clean energy technology, which can directly convert the fuel chemical energy into electrical energy. And when combined with MGT power generation, the energy utilization rate can be further improved. The high temperature exhausted gas of SOFC/MGT combined power generation system can be used as the input of refrigeration and heating system. And it can improve the energy efficiency of entire system. Therefor, the CCHP system is significant for alleviating the energy crisis.Nowadays, the theoretical research and practical application of CCHP system abroad are relatively mature, but it is still relatively less in our country. So. on the basis of the relevant literature and application example at home and abroad, a SOFC/MGT CCHP system is proposed in this paper.The main components of CCHP system in this paper include power generation device, refrigeration device and heating device. Power generation device main include solid oxide fuel cell and micro-gas turbine. Refrigeration device is lithium bromide absorption refrigeration machine. And heating device is the heat exchanger. The main idea of CCHP system is cascade utilization of energy. SOFC/MGT combined system use fuel and compressed air to generate power. And the high temperature exhausted gas after reaction is used to refrigeration or heating.The main works of this paper includes:According to the comparison and analysis,the components of CCHP system was selected and the topping cycle connection way of SOFC and MGT was determined, then the overall system structure was proposed; According to the working principle of each device in system, the mathematical models were deduced respectively; In MATLAB/Simulink simulation platform, simulation models were established based on mathematical models by means of modular modeling, and single models of SOFC and MGT were performance simulated and analyzed; Then the SOFC and MGT were integrated by the topping cycle mode, and its performance is simulated and analyzed; In the end, the whole CCHP system was integrated and simulated; Finally, according to the simulation analysis results of the whole system, the energy management strategy of system was studied which include the island operation mode and grid connected operation mode, and the running process of the system under the two ways were analyzed.