Performance Optimization Of A Phosphoric Acid Fuel Cell/Absorption Refrigerator Hybrid System

Twenty-first Century is the energy century,the world is committed to the development of new energy technologies to get rid of the traditional fossil energy pollution,low efficiency and other issues.The distributed energy system,especially fuel cellsenergy system with high energy density,become the focus of research in the field of energy because of its flexible configuration,clean environment,safety and other advantages,.In the future,China will increase the investment and construction of the smart grid,and the small fuel cell cogeneration project will be a great development prospects.Therefore,it is of great practical significance to study the fuel cell and the absorption refrigerator hybrid system.The hybrid system model that consists ofa phosphoric acid fuel cell and absorption refrigerator is established in this paper.The phosphoric acid fuel cell output power and waste heat at the same time.Absorption Chiller is driven by the released heat,to provide cooling for a building room.The general performance of the hybrid system is analyzed.Specific work:The first chapter introduces the development history of the century development characteristics of new energy and fuel cell technology,and briefly introduces the application of Fuel Cell Combined Cooling Heating and Power for commercial,both at home and abroad.Finally,the development advantage and research significance of the fuel cell cogeneration project in China are discussed.The working principle of PAFC is studied in the second chapter,consideri ng theinfluence of the electrochemical and thermodynamic irreversibilities.Therm odynamic performance determine the reversible voltage of PAFC.The electroch emical analysis of three kinds of potential battery voltage: activation overpotent ial,concentration overpotential and ohmic overpotential are discussed.The effec ts of different operating parameters such as temperature,pressure and electrolyt e concentration on the performance of fuel cell are analyzed.In the third chapter,a model of the absorption refrigerator with a heat source which is much closer to the actual cooling cycle than the three heat source cycle system is established.The effects of various operating parameters on the performance of the refrigerator are analyzed,and the refrigerating capacity and coefficient of performance are optimized.The equivalent power and efficiency of the hybrid system are calculated,and the results show that the efficiency decreases with the increase of the current density,while the power of the composite system has the extreme value.The corresponding current density corresponding to the maximum cooling capacity is lower than the maximum output power,energy waste,presented a collection of fuel cells in excess heat release high current density area using hot water system.The results show that the proposed method improves the system efficiency by about 10%.In the fourth chapter,the unsteady heat transfer model is established,and the relationship between the room temperature and time is obtained,and the target temperature TSET is set up to optimize the time to reach the target temperature.Analysis of different irreversible factors,working temperature,condenser heat absorber allocation rate,as well as the wall thermal conductivity effect on non steady state,the calculation results show that the influence of non steady characteristics.It is found that the irreversibility factor and temperature have great influence on the non steady state performance,while the heat transfer rate of the condenser has little effect.Under different operating conditions,the allowable current density range is different.Different from the steady state characteristics,it is necessary to optimize the non steady state characteristics.The fifth chapter makes a summary of the research content of this paper,and analyzes the advantages and disadvantages of this study.In this paper,the future research directions are put forward.