Solar energy is one of the most potential renewable energy sources to solve energy and environmental crises. Dust deposition on the photovoltaic mirrors greatly decreases the working performance of the mirror and the efficiency of photovoltaic power generation. In this paper, the particle settlement–adhesion evolution mechanism in the flow field of photovoltaic mirrors at night is studied using the computational fluid dynamics-discrete element method. In addition, the effects of air inlet velocity, air relative humidity, particle size and mirror installation inclination on particle settlement–adhesion laws are discussed. The research results show that in the free/nonfree settlement–adhesion motion process, due to the great effect of the relative humidity of air, dust particles can settle and adhere to the photovoltaic mirror by the leading role of the particle gravity force and liquid bridge force, respectively. Dust particles can leave from the flow field of the photovoltaic mirror due to the great effects of the particle collision force and drag force. Decreasing the particle settling velocity or dust deposition density can reduce the dust deposition degree on the photovoltaic mirrors. The research results can provide important theoretical guidance for the removal of dust particles from photovoltaic mirrors.

太阳能是解决能源和环境危机最有潜力的可再生能源之一。灰尘沉积在光伏反射镜上会大大降低反射镜的工作性能和光伏发电效率。本文利用计算流体动力学离散元方法研究了夜间光伏反射镜流场中的颗粒沉降-黏附演化机理。此外，还讨论了进气速度，空气相对湿度，颗粒大小和反射镜安装倾斜度对颗粒沉降-粘附规律的影响。研究结果表明，在自由/非自由沉降—黏附运动过程中，由于空气相对湿度的影响较大，灰尘颗粒可以分别通过颗粒重力和液桥力的作用而沉降并附着在光伏镜上。由于颗粒碰撞力和拖曳力的巨大影响，灰尘颗粒可能会从光电镜的流场中逸出。降低颗粒沉降速度或灰尘沉积密度可降低光伏镜上的灰尘沉积度。研究结果可为光电反射镜中粉尘的去除提供重要的理论指导。降低颗粒沉降速度或灰尘沉积密度可降低光伏镜上的灰尘沉积度。研究结果可为光电反射镜中粉尘的去除提供重要的理论指导。降低颗粒沉降速度或灰尘沉积密度可降低光伏镜上的灰尘沉积度。研究结果可为光电反射镜中粉尘的去除提供重要的理论指导。