| In recent years,the photovoltaic power generation technology develops rapidly.Because of the growing tension in the world today,Solar photovoltaic power generation has been vigorously promoted around the world,its overall energy structure in the proportion of steadily.In the overall energy structure,the proportion of photovoltaic power generation is increasing steadily.As the long-term exposure to solar modules outside the solar radiation,a lot of dust and other impurities in the air will be deposed in the photovoltaic panel surface.Not only it will affect the efficiency of photovoltaic power generation,but also it affects the life of PV modules.Aiming at the problem that the dust removal efficiency of the dust collector of the surface of the photovoltaic module is low and the surface of the module is damaged.In this paper,the dust removal mechanism and device design of PV modules based on pulsed airflow are studied systematically and deeply.Therefore the best effect of removal of adhesion particles can be achieved without damaging the surface of the photovoltaic panel.Firstly,the origin of dust particles is analyzed.From the surface energy of the solid mechanism,the reason why the dust particles adhere to the surface of the photovoltaic panel is explained intuitively.The model of adhesion was established and the source and influence of adhesion force on solid particles were analyzed.The adhesion force of different sizes of particles on the surface of PV panels was calculated and the model of the adhesion of the solid particles on the PV panel was established.Secondly,by analyzing the working principle of the wind knife,the distribution model of the gas dynamic pressure generated by the air knife on the surface of the PV panel is established,and the validity of the dust removal is verified by the theory.The FLUENT and EDEM software was used to establish the fluid-solid coupling simulation model of the dust removal system based on the air knife.The removal of adhesion particles on the PV panel surface was simulated and the removal rule and removal rate of the dust particles were obtained.Thirdly,a simplified experimental scheme based on air knife dedusting system was designed.The experiment platform of dust removal was set up on the surface of photovoltaic panels.The experiments were carried out to verify the accuracy of the simulation results.Through the orthogonal test,the factors that affect the dust removal of photovoltaic panels were studied.By the analysis of range and variance,the influence of PV panel inclination on the dust removal of photovoltaic panels was obtained.Finally,through the simulation analysis of various types of expansion chamber nozzle,and determine the three-stage triangular expansion chamber nozzle FLUENT flow field analysis to determine the optimal size.Then the CFD-DEM coupling in the gas-solid two-phase flow was used to analyze the removal of the dust particles adhering to the photovoltaic panel in the triangular expansion cavity.So the relationship between the removal rate of dust particles and the input pressure of nozzle is theoretically proved to be better than that of air knife in dedusting system. |
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