Performance Optimization And Parameter Design Of A Hybrid Converter Consisting Of A Thermionic Generator With A Graphene-Based Anode And A Thermophotovoltaic Cell

The problem of energy sources has always been the most critical factor in the human development process.At this stage,the main energy sources in the world,including fossil energy of oil,coal,and natural gas,are non-renewable energy sources.The use of new energy sources such as wind power,geothermal energy,hydraulic power,nuclear energy,and biomass energy has developed considerably in recent years,but the development is still limited due to the disadvantage of the technology.The exploration of energy sources is closely related to the long-term development of human society.Due to the intensification of environmental pollution and energy crisis,the development of green energy and the improvement of energy utilization rate have become the issues of great concern to scholars.In this paper,based on a full investigation of the current research status and development prospects of thermophotovoltaic cell and thermionic generator,and the applications of graphene,a novel model of the hybrid converter consisting of a thermionic generator with a graphene-based anode and a photovoltaic cell(TIPV)is proposed.Through theoretical analysis and numerical simulation,the optimized analysis is done on the performance of the system,in which the optimal working region of the relevant performance parameters is determined,and the maximum efficiency and maximum output power density of the system are obtained.The main contents are given as follows:The novel model of the hybrid converter consisting of a thermionic generator with a graphene-based anode and a photovoltaic cell is established and the performance characteristics of the system are studied.The expressions for the power output densities and efficiencies of two single subsystems and the hybrid converter are derived.The effects of the emitter temperature,voltage outputs,and band gap energy on the performance of the hybrid converter are analyzed.The optimally operating bounds of several critical parameters,including the power output density,efficiency,and voltage outputs of the hybrid converter,are determined.It is found that in the optimally working region,the performance of the hybrid converter with a graphene-based anode is obviously better than that with a metallic anode.It is also found that in a certain temperature range,the maximum efficiency and power output density of the hybrid converter may significantly exceed those of the single thermionic generator or photovoltaic cell.The thesis proposes a new idea of using graphene as a collector material in a hybrid TIPV system.The superiority of graphene in the improvement of the performance of the TIPV system is demonstrated by numerical simulation.The result obtained may provide theoretical guidance to the practical design and production of the coupling system composed of Thermionic generator and Thermophotovoltaic cell.