PV/T太阳能光伏光热系统关键参数影响特性研究

利用PV/T太阳能光伏光热系统实验平台针对空气质量流量、太阳辐照强度、环境温度和大气降尘 4种影响系统性能的关键工况参数进行了实验研究。结果表明:在实验设定的流量范围内,PV/T系统的光热和光电效率都随着空气质量流量增大而稳步上升;太阳辐照强度增大时,系统输出电功率随之增大,光热效率变化较小,光电效率有一定程度的降低;环境温度在一定范围内时,系统的输出电功率和集热效率都随着环境温度的增大而增大,而当环境温度超过一定值后,系统的光伏模块受面板温度升高的影响光电转换效率呈下降趋势;随着积尘密度的增大,玻璃盖板的透射率减小,一个月的积尘量会导致系统光电效率和输出电功率分别下降17.84%和18.25%,若以光电效率衰减20%为界限,清洁周期为5周左右。     

太阳能PV/T系统电热输出性能及其Matlab仿真研究

建立了太阳能PV/T(Photovoltaic/Thermal)系统的热电模型,编制了Matlab程序,采用迭代法对电热参数进行耦合求解。研究了PV/T系统在呼和浩特不同季节下的热电效率,电池温度和性能曲线的变化,通过与实验数据对比,验证了该模型具有较高的精度。实验结果显示了环境温度、风速、入射辐射量对太阳能PV/T系统热、电以及综合性能的影响:PV/T系统夏季的日平均电效率、热效率及正午组件最大功率分别为14.1%、34.5%和180.8 W,冬季的日平均电效率、热效率及正午组件最大功率分别为16.1%、24.8%和190.3 W。     

无盖板型水冷式PV/T模块光电/光热综合性能实验研究

无盖板PV/T组件相比于盖板式PV/T组件有更高的光电转换效率,在电能输出方面的优势明显。基于此,提出一种无盖板型水冷式PV/T模块,并搭建由光伏对比模块、水冷式PV/T模块以及无冷却水循环的PV/T对比模块构成的实验平台开展对比实验,研究温度、流量对无盖板PV/T模块电、热转换效率的影响。结果表明,在水冷作用下,PV/T模块的光伏组件温度显著降低,与PV/T对比模块相比发电效率提升11.54%;环境平均温度为21.7 ℃、平均辐照度650 W/m²的测试条件下,流量0.12 m³/h时模块的电效率为17.44%,热效率为19.80%,综合效率达到65.69%,考虑到循环泵消耗的电能,表面积1.93 m²的水冷式PV/T模块全天可存储有效能3.72 MJ。     

基于方管平板光伏光热系统的电热耦合性能对比研究

为了探究方管平板PV/T系统的电热综合性能,基于PV/T系统的能量转换过程,建立PV/T组件电热耦合系统的数学模型,构建了设计工况下PV/T系统的性能评估方法,分析关键参数对PV/T系统性能的影响规律,并对比不同结构下PV/T系统的变工况特性。结果表明：在设计工况下,单方管及多方管结构的PV/T系统电效率在15%左右,总效率在78%以上;随着太阳辐照强度的增大,2种系统下光伏板温度和流体出口温度均会升高,系统总效率也会提高;可以通过提高进口体积流量或者降低进口温度来提高电效率及总效率,在相同运行工况下,单方管平板PV/T系统的总效率低于多方管平板PV/T系统3.1%,且多方管平板PV/T系统的光伏板温度比单方管平板PV/T系统低9.72 K,可见多方管平板PV/T系统的综合性能更优。     

基于相变流体的热管式太阳能PV/T热电联供系统实验研究

文章分别搭建了基于水和相变流体的热管式PV/T热电联供系统实验台,测试分析了相同工况下两个系统的光伏板表面温度、换热水箱温度、热/电功率、热/电效率及综合效率。研究结果表明,在测试工况下,与基于水的热管式PV/T热电联供系统相比,基于相变流体的热管式PV/T热电联供系统光伏板表面温度降低了2℃,蓄热水箱水温升高了1.3℃,日均电效率相对升高了0.8%,日均热效率相对升高了7%,日均综合效率相对升高了10.2%。该研究结果为相变流体在太阳能储存领域的应用提供参考。     

太阳能光伏光热一体化PV/T组件的实验研究

为提高太阳能的综合利用效率及光伏组件的可靠性,设计并搭建了空气型太阳能光伏光热PV/T组件的实验测试平台,并对常规PV组件和空气型PV/T组件的转化效率进行了实验测试,测试结果表明:以空气为传热介质的PV/T组件在被动循环情况下,组件的板温下降约8℃,比普通PV组件的电效率提高约0.1%,PV/T组件通风后的热效率在25%左右,综合效率最高可达72%。分析结果可为空气型PV/T组件的结构优化和建筑供暖提供参考。     

非晶硅太阳能光伏/光热空气集热器性能对比实验研究

文章设计了新型非晶硅太阳能PV/T空气集热器,该空气集热器能够解决传统太阳能PV/T热水器在高温波动情况下,晶硅电池热应力大的问题,同时避免了冬季管道发生霜冻的现象。文章通过实验对比,分析了非晶硅太阳能PV/T空气集热器、单独非晶硅光伏电池和传统太阳能空气集热器的能量效率和[火用]效率的差异。分析结果表明:非晶硅太阳能PV/T空气集热器的平均热效率为45.70%,比传统太阳能空气集热器的平均热效率降低了约25.88%;当空气质量流量增大至0.048 kg/s时,非晶硅太阳能PV/T空气集热器中的非晶硅光伏电池的平均电效率高于单独非晶硅光伏电池,它们的平均电效率分别为4.70%,4.54%;非晶硅太阳能PV/T空气集热器的总[火用]效率高于传统太阳能空气集热器的热[火用]效率和单独非晶硅光伏电池的电[火用]效率,非晶硅太阳能PV/T空气集热器总[火用]效率最大值为7.14%。文章的分析结果为非晶硅太阳能PV/T空气集热器的推广提供了参考。     

板管-铝槽式水冷PV/T集热器优化设计与研究

设计了一种板管-铝槽式结构的太阳能光热光电一体化系统(PV/T),通过数值模拟的方法,获得水流量、管间距、保温层厚度以及入口水温对出口水温、电效率和热效率的影响规律,最终得出该PV/T系统的优化设计方案为:水流量20L/h,管间距80mm,入口水温为环境温度(模拟设置为18℃),保温层厚度30mm。并且发现电效率对水流量的敏感度最大,对保温层厚度的敏感度最小,而热效率对保温层厚度的敏感度最大,对入口水温的敏感度最小。该数值模拟优化设计对实际PV/T系统的进一步设计,实验具有重要的参考价值。     

热管式太阳能PV/T热泵系统的性能研究

文章搭建了热管式太阳能PV/T热泵系统的实验装置,并根据实验装置建立了系统的数学模型,通过实验测试对数学模型进行了验证。研究了系统的热效率、电效率和COP等主要性能参数在全天的变化规律,分析了系统COP偏低的原因和改进措施。结果表明,在测试工况下,日平均热效率为35.4%,日平均电效率为11.0%,日平均COP为2.77,实验值与模拟值的误差均在±15%以内。该研究为热管式太阳能PV/T热泵系统的设计优化与性能研究提供了参考。     

管板式PV/T组件结构参数优化

以无玻璃盖板管板式PV/T组件为研究对象,采用Trnsys软件仿真与实验测试相结合的方法,从发电角度确定吸热板厚度、换热管数量及换热管管径;从成本角度提出适用于不同效率组件、不同光资源区域工况下的最佳设计参数。结果表明：换热管管间距、吸热板厚度和换热管内径对管板式PV/T组件发电性能的影响程度依次减小;以实现PV/T发电性能不低于传统PV组件为目标,换热器结构参数建议为吸热板厚度0.4 mm、换热管管径6 mm及换热管管间距不大于99.2 mm;以全生命周期内总投入最低为目标,Ⅱ类光资源地区最佳管间距为70.86 mm,Ⅲ类和Ⅳ类光资源地区的最佳管间距为82.67 mm;优化后PV/T组件的太阳能利用率达到42.75%～48.69%,发电效率比传统PV高1.17%～2.08%。     

Performance assessment of an integrated PV/T and triple effect cooling system for hydrogen and cooling production

In this paper we study an integrated PV/T absorption system for cooling and hydrogen production based on U.A.E weather data. Effect of average solar radiation for different months, operating time of the electrolyzer, air inlet temperature and area of the PV module on power and rate of heat production, energy and exergy efficiencies, hydrogen production and energetic and exergetic COPs are studied. It is found that the overall energy and exergy efficiency varies greatly from month to month because of the variation of solar radiation and the time for which it is available. The highest energy and exergy efficiencies are obtained for the month of March and their value is 15.6% and 7.9%, respectively. However, the hydrogen production is maximum for the month of August and its value is 9.7 kg because in august, the solar radiation is high and is available for almost 13 h daily. The maximum energetic and exergetic COPs are calculated to be 2.28 and 2.145, respectively and they are obtained in the month of June when solar radiation is high for the specified cooling load of 15 kW.     

蓄冷降温式太阳电池组件的实验研究

根据太阳电池温度特性,研究通过工程热物理途径来提高太阳电池光电转换效率的方法,开发出新型蓄冷降温式太阳电池组件,利用夜间大气自然冷量吸收太阳电池热量,降低其工作温度。室外试验于07年10月～08年11月在广州地区进行,测试分析了该组件及对照组平板式太阳电池组件的温度—电能输出及转换效率特性。结果表明:与平板式组件相比,蓄冷降温式太阳电池组件工作温度大大降低,效率相应提高。蓄冷降温式组件最大温降达26.5℃,瞬时电能输出相对提高18%,全天电能输出增长14%以上。     

太阳能光热与光电/光热系统在中国不同建筑气候带下的性能研究

文章利用TRNSYS动态模拟软件研究了在我国不同建筑气候带条件下,不同类型的太阳能PV/T集热系统和普通太阳能PT集热系统的各项性能.其中,太阳能PV/T集热系统分为基于普通玻璃型太阳能PV/T集热系统和基于Low-e型太阳能PV/T集热系统.文章探究了基于普通玻璃型太阳能PV/T集热系统和基于Low-e型太阳能PV/...     

Thermal modeling of a combined system of photovoltaic thermal (PV/T) solar water heater

In this paper, an integrated combined system of a photovoltaic (glass–glass) thermal (PV/T) solar water heater of capacity 200 l has been designed and tested in outdoor condition for composite climate of New Delhi. An analytical expression for characteristic equation for photovoltaic thermal (PV/T) flat plate collector has been derived for different condition as a function of design and climatic parameters. The testing of collector and system were carried out during February–April, 2007. It is observed that the photovoltaic thermal (PV/T) flat plate collector partially covered with PV module gives better thermal and average cell efficiency which is in accordance with the results reported by earlier researchers.     

Performance evaluation of photovoltaic thermal solar air collector for composite climate of India

The objective of present study is to evaluate the performance of the photovoltaic (PV) module integrated with air duct for composite climate of India. In this case, thermal energy is produced along with electrical energy generated by a PV module with higher efficiency. An analytical expression for an overall efficiency (electrical and thermal) has been derived by using energy balance equation for each component. Experimental validation of thermal model of hybrid photovoltaic/thermal (PV/T) system has also been carried out. It has been observed that there is a fair agreement between theoretical and experimental observations. Further it is concluded that an overall thermal efficiency of PV/T system is significantly increased due to utilization of thermal energy in PV module.     

Photovoltaic/thermal solar hybrid system with bifacial PV module and transparent plane collector

Electric energy production with photovoltaic (PV)/thermal solar hybrid systems can be enhanced with the employment of a bifacial PV module. Experimental model of a PV/thermal hybrid system with such a module was constructed and studied. To make use of both active surfaces of the bifacial PV module, we designed and made an original water-heating planar collector and a set of reflecting planes. The heat collector was transparent in the visible and near-infrared spectral regions, which makes it compatible with the PV module made of crystalline Si. The estimated overall solar energy utilization efficiency for the system related to the direct radiation flux is of the order of 60%, with an electric efficiency of 16.4%.     

Exergetic optimization of a solar photovoltaic thermal (PV/T) air collector

In this paper, an exergetic optimization has been developed to determine the optimal performance and design parameters of a solar photovoltaic thermal (PV/T) air collector. A detailed energy and exergy analysis has been carried out to calculate the thermal and electrical parameters, exergy components, and exergy efficiency of a typical PV/T air collector. The thermal and electrical parameters of a PV/T air collector include solar cell temperature, back surface temperature, outlet air temperature, open‐circuit voltage, short‐circuit current, maximum power point voltage, maximum power point current, etc. An improved electrical model has been used to estimate the electrical parameters of a PV/T air collector. Furthermore, a new equation for the exergy efficiency of a PV/T air collector has been derived in terms of design and climatic parameters. A computer simulation program has been also developed to calculate the thermal and electrical parameters of a PV/T air collector. The results of numerical simulation are in good agreement with the experimental measurements noted in the previous literature. Moreover, the simulation results obtained in this paper are more precise than the one given by the previous literature, and the new exergy efficiency obtained in this paper is in good agreement with the one given by the previous literature. Finally, exergetic optimization has been carried out under given climatic, operating, and design parameters. The optimized values of inlet air velocity, duct length, and the maximum exergy efficiency have been found. Parametric studies have been also carried out. Copyright © 2010 John Wiley & Sons, Ltd.