Simulation Research On CCHP System Based On The Gas Engine And Lithium Bromide Chiller

Traditional points for energy production mode. By burning coal and natural gas, the power plants drive generators to meet the energy needs of the user. Through the combustion, the most chemical in fossil fuel energy is converted into heat, but energy utilization efficiency of the heat energy into electrical is low, most of the heat is not recycled. High temperature flue gas emission to the atmospheric environment not only causes huge energy waste, but also produces environmental pollution.Combined Cooling Heating and Power (CCHP) system is a concept based on the energy cascade utilization, based on a small-scale, decentralized arranged in the vicinity of the user, the refrigeration, heating (heating and hot water) and the integration of the power generation process even more total energy supply system, The purpose is to improve energy efficiency, reduce carbon and harmful gas emissions.CCHP system consist of gas engine and lithium bromide absorption chiller is established, as the power system, gas engine drives the generator subsystem, the absorption chiller uses the gas engine exhaust as the input energy. System provides air-conditioning cooling load in summer and heating load in winter for the users. When the system power shortage, electricity is purchased from power grid; when cold, heat supply is short, the electric refrigerator and boiler can provide cool and heat energy. CCHP system can meet the cooling, heating load, life hot water and electrical loads of the building or district.In this paper, the gas engine and lithium bromide absorption refrigerator mathematical model was established. Simulation study of its cogeneration system is used by MATLAB software. Under the condition of cooling load, the heat load and afterburning conditions changes, System main parameters changes are obtained.First of all, cooling, heating and power system cases are collected.I summarize the advantages of cogeneration systems compared to separate generation systems. Based on the principles of integrated cogeneration system, the system composition is thermally coupled calculation. I sum up reasonable cogeneration system composition.Secondly, compared to CCHP system power subsystem other equipment, gas engine has advantage:gas engine power efficiency can reach 45%, and start quickly, good part load characteristics, strong thermal conversion capability; another advantage is more recyclable waste heat.As the starting point of cogeneration system, gas engine has a direct impact on the downstream lithium bromide refrigerator. While the lithium bromide refrigerator has volume inertia, dynamic response time is far behind gas engine. The quasi steady state model can meet the gas engine modeling demand.The volume inertia of lithium bromide refrigeration machine determines the corresponding lag. The detailed modeling of volume characteristic requires a large number of equations, the complicated calculating process, large amount of calculation. Lumped parameter method of dynamic simulation modeling can basically meet the demand.Finally, cogeneration system composed of gas engine and the lithium bromide absorption chiller dynamic response is simulated. In sequentially changing electrical load, cooling load, the effect of pressure generator, the chilled water outlet temperature, cooling capacity and COP are analyzed. Under the situation of reducing electrical load and unchanging cooling load, lithium bromide chiller start up combustion device, system cooling capacity rises, the simulation results show that the parameters of system back to full capacity, COP coefficient decreased slightly.