Research On Influencing Factors Of Thermophotovoltaic System Efficiency

Thermophotovoltaic is a technology that converts the radiant energy generated by a heat source into electricity through the photoelectric effect by photovoltaic cell.The technology not only has a wide range of radiation sources,but also has high energy output density and high theoretical efficiency.It can also be coupled with traditional Rankine cycle and Stirling machine to realize cogeneration,which has great potential application value.This paper first designed and built a complete thermophotovoltaic system,which includes burner,radiator,photovoltaic cells,cooling facility and integrated facility.The performance test of the burner and the radiator was carried out.The problem of low burner power was directly solved by increasing the burner nozzle,and it was determined that the heat sink connected to the parallel flow passage had better heat dissipation effect.In order to obtain a uniform radiation source and reduce the power loss caused by uneven radiation,the classical two-color method is used to measure the axial temperature of the radiator,and the influence of the porous medium on the uniformity of the temperature distribution of the radiator is studied.The experimental results show that the 10 ppi porous medium has better heat transfer performance than 20 ppi,and the minimum temperature gradient radiation source can be obtained by penetrating different aperture through holes at the center of 10 ppi and varying pore size distribution from 28 mm/20 mm/12mm.Then,the paper studied the effects of methane flow,equivalence ratio,and pore density on the TPV system.The experimental results show that the temperature of the silicon carbide tube,stainless steel tube and porous silicon carbide are improved to different degrees with the increase of fuel flow rate.The radiation performance of the porous silicon carbide radiator is obviously better than the other two types of radiators.When the gas flow rate is 4L/min,the porous silicon carbide radiator has the largest system point efficiency?0.0235%?.There is an optimum equivalent ratio for gas combustion.The study found that the performance parameters of the TPV system were the highest when the equivalent was 0.9.Compared to the combustion at a stoichiometricratio,the system power generation efficiency is increased by 20%at a 0.9equivalent ratio.Immediately after comparing the effect of pore density on the TPV system,it was found that the power generation efficiency of the porous medium with 10 ppi at 0.9 equivalent ratio can be further increased by 29%.The performance of the above variable aperture filled radiators in a series battery system was also tested.It has been found that this method has lower radiator temperature,and the output power of the battery is less than that of the unpenetrated 10ppi porous silicon carbide.At the end of the paper,the one-dimensional Si/SiO₂ photonic crystal filter matched with Si battery was designed by using TFCalc software to solve the problem of excessive battery temperature by reflecting ineffective radiant energy.Taking the?1/2LH1/2L?symmetric film system as the basic unit,it is determined that the film layers of the five basic units have the best frontal reflectance curve.In addition,the secondary peaks in the transmission band are successfully compressed by applying a matching layer between the film and the incident medium and the substrate.Finally,changing the thickness of the film,a filter matching the GaSb battery was designed.