Research Of Solar Thermal Efficiency Of The Solar Stirling Power Generation System

Solar thermal power generation is one of the most popular topic in the currentnew energy field.“Disc condenser+Stirling heat engine” solar thermal powergeneration mode for efficient, clean and non-polluting characteristics is increasinglybeing grown more and more attention. The solar thermal energy conversion is themost important joint in the solar thermal power generation system and its thermalefficiency will directly determine the success or failure of the performances of thesolar thermal power generation system. Therefore, the thesis will take38KW level ofthe solar stirling power generation system as the research object and attempt toinvestigate its solar thermal energy conversion efficiency for the mechanism andnumerical analysis deeply.The article analyzed causes and transfer and conversion paths of the solarthermal energy flow of the solar stirling power generation system. Firstly, dividedeffectively the system as the dish condenser energy unit and the stirling heat engineenergy unit, carried on the qualitative analysis to the power loss and thermalefficiency of each unit. Then, form the perspective of energy transfer mechanism,summarized and analyzed power loss of each unit. The mathematical model of powerloss and thermal efficiency of each unit was established from input solar energy tooutput heat energy in the dish condenser energy unit, input heat energy to outputmechanical energy in the stirling heat engine energy unit through the use of thethermodynamics theory and practical isothermal method and were closely related tostructural parameters and performance parameters of each unit. Using the MATLABnumerical analysis software, with the38KW level of solar stirling power generationsystem as the instance, numerical analyzed power loss and thermal efficiency of eachunit and obtained the significant results of each unit and feature relationship ofstructure, operation parameters between power loss and thermal efficiency. Finally,the significant effect of power loss was analyzed. It was concluded that theregenerator was the biggest impact of power loss in a variety of components. For thepurpose of improving the thermal efficiency, the structural parameters of the regenerator had been optimized.The study showed that condenser optical loss, heat reflective heat loss andradiation heat loss of the heat absorber are more amount than all kinds of heat loss ofthe dish condenser energy unit and condenser optical loss was the most significant. Avariety of power loss of the stirling heat engine energy unit was segmented into flowresistance loss and heat loss, flow resistance loss of the regenerator was the biggestpower loss in many of flow resistance loss. Heat conduction loss and shuttle heat losswere main heat loss and heat conduction loss of the regenerator was the biggestimpact heat loss among all kinds of heat loss. Power loss and thermal efficiency ofeach unit were closely related to structural parameters and performance parameterswithin the system. The collector optical errors and aperture diameter of the heatabsorber were the key factors influencing power loss and thermal efficiency of thedish condenser energy unit. Condenser optical loss fell along with the increase ofaperture diameter, different optical errors corresponded the best aperture diameter.Reducing the optical errors could reduce properly the power loss and improve thethermal efficiency of the dish condenser energy unit. The solar radiation intensity andthe average pressure were main performance parameters impacting on power loss andthermal efficiency of the stirling heat engine energy unit. Increasing the averagepressure would add the flow resistance loss and reduce the thermal efficiency with thesolar radiation intensity was constant. When the work cycle power of the stirling heatengine energy unit were guaranteed, the thermal efficiency would be improvedthrough reducing the average pressure.After optimization, main structure parameters of the regenerator had beenchanged. The length of the regenerator was3.3cm, the diameter of the regeneratorwas6.6cm, the packing was made of stainless steel wire mesh and the porosity was0.708. Compared to the original data, the pressure drop loss and uneven temperatureloss were decreased significantly by27.82%and19.63%, the total power loss wasdecreased by19.96%and the solar thermal conversion efficiency of the solar stirlingpower generation system had been improved.Through the study of the solar thermal conversion efficiency of the solar stirlingpower generation system, numerous research results had been obtained that wouldprovide the theoretical support and guidance significance to design a kind of solar stirling power generation system which has the characteristics of efficient, reliableand stable work.