Optimum Analysis On The Performances Of A Solar Thermophotovoltaic Cell And A Solid Oxide Fuel Cell Coupling System

Energy is the most significant foundation to the survival of humans.In a certain extent,the long-term development of human society depends on the application of high quality energies and the innovation of energy technologies.On the one hand,the renewable energy becomes the main source of energy application in the future individually,whose emergence has solved some problems such as the limitation of the conventional energy,the deterioration of the environment caused by combustion,and so on;On the other hand,optimizing the design of energy consumption devices and improving the energy conversion efficiency are increasingly becoming an interesting topic attracting researchers.The performance of a solar thermophotovoltaic cell is evaluated and the model of a solid oxide fuel cell-based hybrid system is proposed,in which the main irreversible heat losses are taken into consideration.Through calculation and analysis,the maximal efficiency or power output density of systems are determined by optimally designing the important parameters.The concrete research contents include following two parts.In the first part of this article,we study the optimal performance of a novel solar thermophotovoltaic cell.Considering the optical losses of the lens,the irreversible reflection and the radiation heat flux from the surfaces of the absorber and the emitter to the environment,we derive the expressions of the efficiency and output power of the system.Through optimizing the temperatures of the emitter and photovoltaic cell,concentrating ratio of the optical lens,area ratio of the absorber to emitter,and the energy gap of semiconductor material,the maximal efficiency of the system is calculated,and the best working ranges of main parameters are determined.The results obtained can provide some useful methods for deeply researching the performance of solar thermophotovoltaic cells.In the second part of this article,the optimal performance of a coupling system consisting of a solid oxide fuel cell and a thermophotovoltaic cell is investigated.On the basis of the existing models of a reforming solid oxide fuel cell and a thermophotovoltaic cell,we establish the new model of a reforming solid oxide fuel cell-thermophotovoltaic cell coupling system.Considering the effects of the main irreversible losses in two subsystems and heat losses between the two subsystems on the whole performance of the system,we derive the expressions of the efficiency and power output.The power output density is taken as an objective function to evaluate the systemic performance.The maximum power output densities of the coupling system at the different temperatures of the fuel cell are calculated and the optimal regions of main parameters are determined.The proposed model is directly extended to discuss the performance of the solid oxide fuel cell-thermophotovoltaic cell coupling system using hydrogen as a fuel.The results obtained show that the optimal performances of a reforming solid oxide fuel cell-thermophotovoltaic cell coupling systems or a solid oxide fuel cell-thermophotovoltaic cell coupling system are better than those of the other coupling systems of the solid oxide fuel cell reported in literature.The main irreversible losses existing in actual systems have been considered in the two models proposed here.The results obtained not only have theoretical significance but also may provide some references for the practical design and manufacture of solar thermophotovoltaic cells and solid oxide fuel cell-thermophotovoltaic cell coupled systems.