建筑阴影影响下半透明晶硅光伏幕墙热电耦合机理与实验研究

Semi-transparent crystal silicon photovoltaic façade is widely used, but the electrical performance of the semi-transparent crystal silicon photovoltaic façade under building shaded conditions, especially its thermal performance, is not well understood. System mismatch and hot spot which caused by building shadow have seriously affected the power generation efficiency of facade and building energy consumption. In this proposal, investigation of thermal-electrical coupled mechanism and experiment of semi-transparent crystal silicon photovoltaic façade under building shaded conditions are to be carried out. The theoretical model, numerical methodology and experimental method of the façade affected by building shadow are to be established. The semi-transparent crystal silicon photovoltaic façade is to be regarded as a multilayer transparent control unit with a series of equally spaced spontaneous heating elements, and each element changes temperature itself. The radiation transfer relationship of semi-transparent crystal silicon photovoltaic façade is to be calculated by applying the energy balance relation of multilayer transparent system and the optic-electro and optic-thermal transfer equation of distributed photovoltaic under building shaded conditions is to be established. Coupling the process of PV thermal and electrical generation, heat transfer and radiation transfer to establish a thermal-electrical coupled model which can accurately describe the performance of semi-transparent crystal silicon photovoltaic façade affected by building shadow. The model and numerical methodology are to be verified by experiments. On this basis, calculating the shadow distribution of the facade and solar radiation, the performance of semi-transparent crystal silicon photovoltaic façade is to be simulated and analyzed, and the internal structure parameters and operating modes of the semi-transparent crystal silicon photovoltaic façade are to be optimized, providing theoretical guidance for its engineering application.

半透明晶硅光伏幕墙应用广泛，然而其在建筑阴影影响下的发电特性，特别是热特性并未得到很好的理解，由建筑阴影引起的系统失配和热斑效应已严重影响其发电效率和建筑能耗。本项目开展建筑阴影影响下的半透明晶硅光伏幕墙的热电耦合机理与实验研究，建立幕墙的理论模型、数值分析与实验方法。将半透明晶硅光伏幕墙看成内部存在一系列等间距变温自发热体的多层半透明控制单元，应用多层透过体系界面能量平衡关系，计算半透明晶硅光伏幕墙的辐射传递，建立建筑阴影影响下的分布式光伏光电光热转换方程，将发电发热过程、传热过程和辐射传递过程耦合，建立能准确描述受建筑阴影影响的半透明晶硅光伏幕墙热电耦合模型，并通过实验对模型和数值方法进行验证。在此基础上，计算幕墙的阴影分布和太阳辐照，模拟分析和优化半透明晶硅光伏幕墙的内部结构和运行模式，为半透明晶硅光伏幕墙的工程应用奠定理论基础。

建筑光伏幕墙在建筑中已得到广泛应用，然而经常受周围建筑物、建筑本身和建筑屋檐等物体遮挡形成的阴影影响，而且较小面积的阴影遮挡会造成系统较大发电损失，引起光伏电池出现热斑现象。本研究在长沙建立了半透明晶硅光伏幕墙的试验测试平台，开展建筑阴影影响下的半透明晶硅光伏幕墙热电耦合机理与实验研究，建立一套能够正确描述受建筑阴影影响的半透明晶硅光伏幕墙的理论模型和数值分析方法。主要成果与结论如下：1）建立了屋檐阴影和城市建筑群对光伏幕墙遮挡的动态阴影模型，用来实时计算半透明晶硅光伏幕墙阴影分布，为半透明晶硅光伏幕墙在阴影影响下的性能模拟提供基础；2）建立了半透明晶硅光伏幕墙在阴影影响下的发电模型、传热模型和光学模型，并将上述模型进行耦合，建立了光伏幕墙光电光热耦合模型；3）建立了光伏幕墙在阴影影响下的实验测试平台，测试了光伏幕墙的全年性能，并利用实验数据验证了光伏幕墙光电光热耦合模型；4）研究了屋檐阴影对光伏幕墙性能的影响，优化了屋檐阴影影响下的系统参数；5）研究了城市建筑群对光伏幕墙性能的影响，模拟分析和优化各个参数对光伏幕墙性能的影响。本研究为半透明晶硅光伏幕墙的设计和应用提供理论基础和指导。