Node Document

荒漠化地区大气环境对光伏板发电性能影响研究

Study on the Influence of Atmospheric Environment on the Power Generation Performance of Photovoltaic Panel in Desertification Areas

To avoid encountering 504 error when downloading big files,please take CAJ download or PDF download by chapter as your first priority.

【Author in Chinese】 刘天胜

【Supervisor】 李兴财

【Author's Information】 宁夏大学, 凝聚态物理, 2020, 硕士

【Abstract in Chinese】 光伏发电在众多新型绿色能源中有着许多优点,如清洁无污染、技术最为成熟、装置结构简单适用推广等。荒漠化地区有着丰富的太阳能资源,光照强、空气湿度低等有利环境条件,为光伏电站的发展提供了得天独厚的条件,但环境条件和其自身性能对其发电量也有一些限制因素,如光伏板温度、入射辐照度和空气中悬浮的沙尘颗粒等因素。因此,如何准确预测光伏模块发电效率是近些年来相关领域众多学者研究的热门课题。入射辐照度的预测已取得了良好进展,但是光伏电池温度的预测模型问题仍是这一领域的研究热点。本文针对光伏电站内沙尘沉积、沙尘颗粒对光伏板影响机理以及光伏板温度预测模型三个方面的基本问题进行了研究。主要工作有:首先,通过野外试验与数值建模和分析相结合的方法研究了光伏电站内的风速廓线和沙尘沉降量计算问题,研究结果表明:(1)光伏板阵列中风速廓线服从改进的普朗特模型形式;(2)基于粗糙面条件下沙尘干沉降速率公式分析了不同条件下的沙尘干沉降速率,基于此可初步实现对大气降尘水平通量的预测;(3)光伏板倾角会影响积尘的分布规律,且随着倾角从0度增加到50度,光伏板表面的沙尘由其顶端逐渐向底端转移,在30度时相对集中于板的中轴线处,且积尘量呈现先增加后减小的变化规律,在30度角时积尘量最小。基于此可近似建立水平面内沙尘沉积量和倾斜平面沙尘沉积量的转化关系,从而为光伏阵列中光伏板表面积尘量的预测提供基础。其次,基于MIE散射理论,研究了太阳光照射下颗粒外部电磁场分布规律,发现沉积沙尘对光伏板具有聚光增温效应,且沿光入射方向,随着到颗粒径向距离的增加,这种现象急剧减弱,但随着颗粒粒径与入射波波长比值的增加,这种效应会增强。同时结合相关理论分析,我们认为通过设计特殊的光伏板结构有可能逆转积尘对光伏板的负面影响。这些结果对于准确认识和有效遏制积尘对光伏系统的负面影响有着重要意义。最后,基于宁夏中卫腾格里沙漠光伏产业园的实测数据建立了一种能定量反映太阳辐射强度、环境温度、风速和风向对沙漠光伏电站光伏板温度影响的回归预测模型。在此基础上,结合光伏电池的等效电路模型讨论了沙漠光伏组件在不同环境因素下的电能输出特性。相关数值仿真结果表明:光伏组件输出功率的准确预测必须考虑到太阳辐射强度、气温、风速、风向以及沉积物质量和透明度;随着沉积物颗粒透明度的降低,光伏组件的最大输出功率有不同程度的降低。同时我们发现,对于具有相同透光率的表面沉积不同类型颗粒的光伏玻璃板,随着颗粒透明度比值的增加,沉积物质量密度比呈指数增长。这一结果可以解释当前许多文献中相同透光率的积尘光伏玻璃上沉积物的质量分布密度相差数个量级的现象。本文研究在光伏电站积尘量的预测和积尘对光伏系统影响机理方面进行了初步的讨论,并给出了一种适用于荒漠化条件下的光伏模块温度预测模型,有助于建立更有效的沙漠环境下光伏发电量预测模型。

【Abstract】 Photovoltaic power generation has many advantages in many new green energy sources such as cleanness and no pollution,the most mature technology,simple device structure,application and popularization,etc.Desertification areas have abundant solar energy resources,strong illumination,low air humidity and other favorable environmental conditions,which provide unique conditions for the development of photovoltaic power stations.However,environmental conditions and their own performance also have some limiting factors on their power generation,such as photovoltaic panel temperature,incident irradiance and dust particles suspended in the air.Therefore,how to accurately predict the power generation efficiency of photovoltaic modules is a hot topic for many scholars in related fields in recent years.Good progress has been made in the prediction of incident irradiance,but the prediction model of photovoltaic cell temperature is still a research hotspot in this field.In this paper,the basic problems of dust deposition in photovoltaic power station,the influence mechanism of dust particles on photovoltaic panels and the temperature prediction model of photovoltaic panels are studied.The main tasks include:Firstly,the calculation of wind speed profile and dust settlement in photovoltaic power station is studied by combining field test with numerical modeling and analysis.The results show that:(1)the wind speed profile in photovoltaic panel array obeys the improved Prandtl model;(2)Based on the formula of dry dust deposition rate under rough surface condition,the dry dust deposition rate under different conditions is analyzed,and the horizontal flux of atmospheric dust deposition can be preliminarily predicted based on this formula.(3)The inclination angle of the photovoltaic panel will affect the distribution law of dust accumulation.With the increase of the inclination angle from 0 degree to 50 degree,the dust accumulation on the surface of the photovoltaic panel gradually shifts from the top to the bottom,and is relatively concentrated at the central axis of the panel at 30 degree,and the dust accumulation shows a change law of increasing first and then decreasing,and the dust accumulation is the smallest at 30 degree.Based on this,the conversion relationship between the dust deposition in horizontal plane and the dust deposition in inclined plane can be approximately established,thus providing a basis for the prediction of the dust deposition on the surface area of photovoltaic panels in photovoltaic arrays.Secondly,based on MIE scattering theory,the distribution law of electromagnetic field outside the particles under sunlight irradiation is studied.It is found that the deposited dust has a condensing and warming effect on photovoltaic panels,and this phenomenon weakens sharply along the incident direction with the increase of the radial distance to the particles,but this effect will increase with the increase of the ratio of particle size to incident wave wavelength.At the same time,combined with relevant theoretical analysis,we believe that it is possible to reverse the negative impact of dust accumulation on photovoltaic panels by designing a special photovoltaic panel structure.These results are of great significance for accurately understanding and effectively containing the negative impact of dust accumulation on photovoltaic systems.Finally,based on the measured data of Tengger Desert Photovoltaic Industrial Park in Zhongwei,Ningxia,a regression prediction model is established,which can quantitatively reflect the influence of solar radiation intensity,ambient temperature,wind speed and wind direction on photovoltaic panel temperature of desert photovoltaic power station.Therefore,combined with the equivalent circuit model of photovoltaic cells,the power output characteristics of desert photovoltaic modules under different environmental factors are discussed.Relevant numerical simulation results show that the accurate prediction of photovoltaic module output power must take into account solar radiation intensity,air temperature,wind speed,wind direction,sediment quality and transparency.With the decrease of the transparency of sediment particles,the maximum output power of photovoltaic modules decreases to varying degrees.At the same time,we found that for photovoltaic glass plates with the same light transmittance and different types of particles deposited on the surface,the sediment mass density ratio increases exponentially with the increase of the particle transparency ratio.This result can explain the phenomenon that the mass distribution density of deposits on dusty photovoltaic glass with the same light transmittance differs by several orders of magnitude in many literatures.In this paper,the prediction of dust accumulation in photovoltaic power stations and the influence mechanism of dust accumulation on photovoltaic systems are preliminarily discussed,and a temperature prediction model of photovoltaic modules suitable for desertification conditions is given,which is helpful to establish a more effective prediction model of photovoltaic power generation in desert environment.

【Keywords in Chinese】 沙尘沉降温度MIE理论辐照度风速廓线
【Key words】 Dust DepositionTemperatureMie theoryIrradianceWind Profile
  • 【Contributor】 宁夏大学
  • 【Year of Internet Publish】202103
Snapshot search of full-text: 

Knowledge network:

Citation network of current document
网页聊天
live chat
在线营销
live chat