Numerical Simulation Of Dust Deposition On The Photovoltaic Panels Under Windy And Dusty Environment

With the increase in global energy demand and the shortage of fossil energy,renewable energy sources such as solar,wind,and hydropower have attracted more and more attention.Many desert areas in Northwest my country,with abundant solar irradiance and cheap land resources,are very suitable for the construction of large-scale photovoltaic power stations.However,the harsh climate conditions in Northwest China will have a negative impact on the power generation efficiency of photovoltaic modules.Especially,the deposition of sand particles on the surface of photovoltaic panels will greatly reduce the power generation efficiency of photovoltaic modules.At present,the development prospects of technologies for improving the utilization rate of solar photovoltaics have been limited,and people have turned their attention to how to improve the operation of photovoltaic systems and the maintenance of photovoltaic modules in the later period.In this paper,the surface settlement distribution of photovoltaic panels is simulated and analyzed by numerical simulation.As the wind field around the photovoltaic module and the sand settling process will have an impact on the sand settling on the surface of the photovoltaic panel,these two aspects are studied and analyzed in the previous paper.The main contents of the article are as follows:Firstly,the relevant research status is summarized and analyzed.In addition,taking a photovoltaic module in a photovoltaic power station in Zhongwei as a model,the DPM model was used to analyze the flow field distribution around the photovoltaic panels,and the effects of incoming wind speed,incoming wind direction and photovoltaic panel height on the wind speed profile between photovoltaic panels were simulated and analyzed.The results show that:(1)the wind speed profiles between photovoltaic panels are very similar at different wind speeds;(2)When the incoming wind direction is different,the wind speed profiles between photovoltaic panels differ greatly;(3)The friction wind speed of the wind profile increases exponentially with the increase of the height of the photovoltaic panel.According to the fitting curve,the friction wind speed of the wind profile at this moment can be deduced from the height of the photovoltaic panel.(4)The installation height of photovoltaic panels also has an impact on the wind speed profile between photovoltaic panels.On this basis,the influence of the installation Angle of photovoltaic panels on the wind speed profile between photovoltaic panels is studied.It is found that the installation Angle has a small impact on the friction wind speed,but a greater impact on the roughness.Secondly,based on the Euler model,the wind-sand two-phase flow around the photovoltaic array was simulated,and the volume fraction distribution of sand phase and the velocity distribution of sand particles between photovoltaic panels were simulated with different installation angles,different sand particle sizes,different incoming wind directions,different incoming wind speeds,as well as the different layout of photovoltaic panels.The results show that:(1)The larger the installation Angle of photovoltaic panels,the smaller the distribution of sand volume fraction on the leeward side of photovoltaic panels;(2)The larger the incoming wind speed,the greater the difference in the distribution of the volume fraction of sand particles at different locations around the photovoltaic panel;(3)The installation spacing of photovoltaic panels also has an effect on the distribution state of sand particles,which is not involved in previous studies;(4)When the inflow wind direction and sand particle size are different,the velocity distribution of sand particles and the volume fraction distribution of sand phase are also different between photovoltaic panels.Finally,the sand deposition state on the surface of photovoltaic panels under different installation angles,different inlet wind directions and different display layouts was simulated.The research shows:(1)When the installation Angle of photovoltaic panels increases from 25° to 60°,the deposition mass of sand particles on the surface of photovoltaic panels increases first and then decreases;When the installation Angle is 30°,the deposition quality of sand particles on the surface of photovoltaic panels reaches the maximum.The deposition distribution of sand particles on the surface of photovoltaic panels is different with different installation angles.(2)The wind direction angle has a relatively small impact on the deposition quality of sand particles on the surface of the photovoltaic panel,and has a greater impact on the distribution of deposition on the surface of the photovoltaic panel.(3)There is an optimal installation spacing at different installation angles to minimize the deposition mass on the surface of photovoltaic panels;Taking PV panels with 35° installation inclination as an example,the total deposition amount of PV panels reached the minimum when the height to plate spacing ratio was 0.945.The above research lays the foundation for further analysis of the impact rate of sand and dust deposition on the power generation efficiency of photovoltaic modules,and also provides a theoretical basis for the cleaning and maintenance of photovoltaic modules in the later stage of photovoltaic power plants.