Research On The Capacity Configuration Of CCHP System

With the development of the economy, the issue of energy crisis and environmental pollution becomes increasingly prominent end emergency, therefore, more and more countries have focused on the distributed generation system. Distributed generation (DG), which takes advantage of the renewable energy as the input fuel, can provide the users with various kinds of demands in the local neighborhood and reduce the energy loss on the transmission procedure. One of the most typical applications of DG is the combined cooling, heating and power (CCHP) system, which use the generated high-grade thermal energy for generation and the low-grade thermal energy to meet the heating and cooling demand. Thus the CCHP system can realize a cascade utilization of energy and reduce the emissions.CCHP system can provide the users with the cooling, heating and power demands; therefore it is a high coupling system with multiple equipment and complicated structure, which poses a challenge for the optimal configuration and the performance evaluation of system. The main contents of this paper are structured as follows:1) We choose economy as the performance indicator for the CCHP system in this paper, which corresponds to the configuration, operation strategy of the tri-generation system. For the system operating under FEL and FTL mode, the configuration of the system can be determined by α(β) percentage of the thermal (electricity) demand. The simulation result shows that simple FET and FTL mode are not always the best operation modes.2) For the optimal operation mode, establish a CCHP optimal configuration model with economy as the objective, energy balance and equipment operation constraints by mathematical programming. The final optimal configuration results are given by simulation.3) The optimal configuration of CCHP system not only related to the choice of the equipment and the operation strategy, but also corresponding to the price of the energy; therefore, a sensitivity analysis of the price of electricity and natural gas was made. The simulation result shows that with the increase of the price of the electricity, the economy of CCHP system become better and better compared with the SP system and with the increase of the price of the natural gas, the economy of CCHP system shows a certain decline.4) The combination between CCHP system and renewable energy is one of the main development direction of future CCHP system. Therefore, the capacity configuration of combined cooling heating and power system containing photovoltaic is studied in the paper. The results show that the economic characteristic of combined cooling heating and power system containing photovoltaic is better than that not containing photovoltaic, due to its advantage of selling electricity to the power grid.