PV-ETFE气枕屋顶系统性能研究

发布时间：2018-05-19 22:07

本文选题：ETFE气枕 + 柔性非晶硅太阳能电池　；参考：《上海交通大学》2015年博士论文

【摘要】：乙烯-四氟乙烯(ethylene tetrafluoroethylene,ETFE)气枕膜结构具有轻质、高透光、自洁性能好等优点,广泛应用于大型体育场馆和机场航站楼等对建筑美学、建筑采光物理和结构性能有较高要求的建筑结构体系。ETFE气枕结构的特点有:ETFE薄膜的高透光率使得气枕内温度较高,ETFE气枕具有模块化、标准化和工厂预制,可适应于复杂大跨空间网格结构。这些特点与非晶硅太阳能电池(Photovoltaic,PV)的柔韧性和高温适应性相匹配,将ETFE气枕和PV结合为光伏膜结构一体化建筑。利用PV的光电光热效应将太阳能转化成电能和热能,降低建筑能耗,使建筑成为低耗能、可持续和对环境友好的建筑。基于此,本文提出了将柔性PV与三层ETFE气枕结合的新型光伏一体化膜结构(简称PV-ETFE气枕屋顶),具有利用电能、收集热能、避免外界环境对PV的不利影响和PV高温对结构用ETFE薄膜的直接影响的特点。考虑PV将对建筑体系产生新的系统性能和结构行为,本文围绕相关问题开展了试验、分析和理论研究,并取得了一些具有研究意义和工程价值的成果。首先,第三章进行了不同加载速度和加载温度下ETFE薄膜单轴拉伸试验,提出了一种基于数学拟合求屈服点和弹性模量的方法。通过分析所得力学性能和对比已有文献值证明了该方法的正确性和合理性,表明该方法可较为准确和快速确定ETFE薄膜的力学参数。基于宏观现象、各向同性材料小应变和Clausius-Duhem不等式,推导了ETFE薄膜的应力应变关系,编写了基于两步法确定本构方程参数的程序。与单轴拉伸力学性能不同,ETFE薄膜单轴循环拉伸力学性能可用于分析ETFE结构受循环荷载作用的结构行为。因此,第四章进行了8组不同加载应力幅值的试验,编写了计算材料常数的程序,通过对弹性模量、屈服应力、屈服应变、棘轮应变和滞回环面积的的研究,揭示了ETFE薄膜粘弹塑性力学机理。为了研究PV-ETFE气枕屋顶的系统性能,第五章设计研制了一套由三层ETFE气枕和柔性PV结合的建筑屋顶系统及其综合测试系统,进行了冬季和夏季典型天气条件的实测试验,测得了系统的电气参数、热参数和结构参数,分析了系统的光电性能、光热性能和气枕压力性能等。试验结果分析验证了该PV-ETFE气枕屋顶系统的可行性,揭示了该系统独特的技术特征。PV温度值及其变化规律是分析气枕结构温度场的基础,而ETFE气枕结构的温度场是研究系统建筑热物理和热结构分析的必要条件。因此,第六章首先基于能量守恒法推导了PV的动态热模型,研究了冬夏季晴和晴转多云天气的温度变化规律。然后在稳定温度边界条件和不可压缩流体的假定下,建立二维模型分析了在夏季晴11:30~12:30气枕内空气温度场和速度场的特征,基于该温度场计算了气枕上层膜和下层膜的表面热传递系数,结果表明PV-ETFE气枕的表面热传递性能优于常规ETFE单层结构的热传递性能。最后,第七章基于ETFE薄膜不同温度测得的非线性本构模型,以计算流体动力学方法模拟得到的气枕表面温度作为温度边界条件,分析了气枕结构在内压250Pa和膜面预应力1.0MPa下气枕的应力、应变和变形。为了得到PV-ETFE气枕结构性能在压力和预应力变化下的合理规律,即压力250Pa~450Pa和膜面预应力1.0MPa~3.0MPa,本文通过25种工况分析了气枕应力和应变的安全系数以及变形的使用性能,揭示了PV-ETFE气枕结构的力学行为特征。
[Abstract]:Ethylene tetrafluoroethylene (ethylene tetrafluoroethylene, ETFE) gas pillow membrane has the advantages of light quality, high light transmittance and good self cleaning properties. It is widely used in the construction aesthetics of large sports venues and airport terminal buildings. The structure of building structure with high requirements for the physical and structural properties of building lighting and structure system.ETFE gas pillow structure are: ETFE film High transmittance makes the temperature of the air pillow high, the ETFE gas pillow is modularized, standardized and factory prefabricated. It can adapt to the complex and large span space grid structure. These features match the flexibility and high temperature adaptability of the amorphous silicon solar cells (Photovoltaic, PV). The ETFE gas pillow and PV are integrated into the integrated architecture of the photovoltaic membrane structure. The use of PV The photoelectric and photothermal effect transforms solar energy into electric energy and heat energy, reduces building energy consumption and makes buildings become low energy consumption, sustainable and environmentally friendly buildings. Based on this, a new type of photovoltaic integrated membrane structure (called PV-ETFE pillow roof), which combines flexible PV with three layers of ETFE gas pillow, is proposed in this paper. The adverse effect of boundary environment on PV and the direct influence of PV high temperature on the structure of ETFE film. Considering that PV will produce new system performance and structure behavior to the architecture system, this paper carried out experiments, analysis and theoretical research around the related problems, and obtained some achievements with research meaning and engineering value. First, third chapters are carried out. A single axis tensile test of ETFE films at different loading speeds and loading temperatures was carried out. A method of calculating the yield point and elastic modulus based on mathematical fitting was proposed. The correctness and rationality of the method were proved by analyzing the mechanical properties and comparing the existing literature values. It shows that the method can accurately and quickly determine the mechanics of ETFE film. Parameters. Based on macroscopic phenomena, small strain of isotropic material and Clausius-Duhem inequality, the stress-strain relation of ETFE thin film is derived. A program based on two step method to determine the constitutive equation parameters is written. The mechanical properties of ETFE thin films are different from the uniaxial tensile mechanical properties. The mechanical properties of the single axis cyclic stretching can be used to analyze the cyclic loading of the ETFE structure. Therefore, the fourth chapter carries out the experiment of 8 groups of different loading stress amplitude, and writes the program to calculate the material constant. Through the study of the elastic modulus, yield stress, yield strain, ratcheting strain and hysteresis loop area, the viscoelastic plasticity mechanism of ETFE film is revealed. In order to study the system performance of the PV-ETFE air pillow roof, The fifth chapter designs and develops a set of building roof system and its comprehensive testing system, which is combined with three layers of ETFE gas pillow and flexible PV. The test of typical weather conditions in winter and summer is carried out. The electrical parameters, thermal parameters and structural parameters of the system are measured, and the system's photoelectricity, photothermal performance and pressure performance of the gas pillow are analyzed. The result analysis proves the feasibility of the PV-ETFE air pillow roof system, and reveals that the unique technical characteristics of the system.PV temperature value and its variation law are the basis of the analysis of the temperature field of the air pillow structure, and the temperature field of the ETFE pillow structure is the necessary condition for the study of the thermal physical and thermal structural analysis of the system building. Therefore, the sixth chapter is first based on the analysis of the thermal physical and thermal structure of the system. The dynamic thermal model of PV is derived by the energy conservation method. The temperature change law of clear and cloudy and cloudy weather in winter and summer is studied. Under the assumption of stable temperature boundary condition and incompressible fluid, a two-dimensional model is established to analyze the characteristics of air temperature field and velocity field in the Xia Jiqing 11:30~12:30 gas pillow. The temperature field is calculated based on the temperature field. The surface heat transfer coefficient of the upper and lower layers of the gas pillow shows that the heat transfer performance of the surface heat transfer of the PV-ETFE gas pillow is better than that of the conventional ETFE single layer structure. Finally, the seventh chapter is based on the nonlinear constitutive model measured at different temperatures of the ETFE film, and the temperature of the surface of the pillow is calculated by the calculation of the hydrodynamics method as the temperature. The stress, strain and deformation of the air pillow structure under the internal pressure of 250Pa and the film surface prestressed 1.0MPa are analyzed by the boundary conditions. In order to obtain the reasonable law of the structure performance of the PV-ETFE pillow under pressure and prestress, that is, the pressure 250Pa~450Pa and the membrane surface prestress 1.0MPa~3.0MPa, the stress and strain of the air pillow are analyzed by 25 working conditions. The safety factor and the performance of deformation reveal the mechanical behavior characteristics of PV-ETFE air cushion structure.
【学位授予单位】：上海交通大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TU38

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