Dynamic Energy And Operating Economy Analysis Of Micro-turbine CCHP System

Micro-turbine CCHP system based on the concept of energy cascade utilization which provided users with electricity,cooling and heating.It was an integrated energy system and had good energy efficiency and economic benefits.The domestic economic studies of micro-turbine CCHP system were often static economic analysis based on estimated building loads.It didn’t reflect the actual operation of the unit’s performance.Therefore,the dynamic simulation model of micro-turbine CCHP system was built based on dynamic building loads and dynamic operating economy was calculated in this paper.The main results were listed as follows:Firstly,hourly load of the three official buildings in Hangzhou Gas Group was obtained by combining measurement and EnergyPlus simulation.The results showed that the simulation loads agreed well with measured loads of the third floor.The parameters in EnergyPlus were reasonably and could be used for full-year hourly loads simulation of three buildings.The hourly loads could be used for dynamic simulation of micro-turbine CCHP system.Secondly,based on the modular idea,the simulation model of micro-turbine CCHP system was built with Matlab/Simulink.The model was validated by measured data.The results showed that the deviation of the simulation and measured value was within 10%,in a good agreement.The simulation date contained the crucial performance parameter of micro-turbine and gas-direct-fired machine.Therefore,it could be used for micro-gas turbine CCHP dynamic energy simulation.Thirdly,operating economy of CCHP system was analyzed by thermodynamic and technical economy according to the simulation results of micro-turbine CCHP system in Hangzhou Gas Group.The results showed that the primary energy utilization rate of micro-turbine CCHP system in summer was higher than that in winter.Absorption refrigeration cycle was benefit to improve primary energy utilization rate.Compared with two conventional energy supply systems,the annual energy saving ratio of micro-turbine CCHP system was 2.29%and 3.5%respectively.The exergy effciency of micro-turbine CCHP system was slightly higher than two conventional supply systems with minor difference.When all of the flue gas was used,the annual energy saving ratio of micro-turbine CCHP system was 18.69%and 20.13%respectively compared with two conventional energy supply systems.Therefore,the optimization of plant operation would improve the energy efficiency of CCHP system in the current configuration.Based on the current energy prices in Hangzhou,compared with two conventional energy supply systems,the annual operating costs of micro-turbine CCHP system could save 50,500 Yuan and 37,000 Yuan respectively.Currently,due to the high initial investment of micro-turbine CCHP system,the additional payback period of CCHP system was still too long.Therefore,it was necessary to develop a reasonable energy prices or obtain subsidies from the government to improve the economy of CCHP system.