基于方管平板光伏光热系统的电热耦合性能对比研究

Comparison of Electrothermal Coupling Performance Based on Flat Plate PV/T System of Square-tube

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。

In order to explore the comprehensive electrothermal performance of square-tube flat plate PV/T system,a mathematical model of electrothermal coupling system in a PV/T module was established according to the energy conversion process of the PV/T system.A performance evaluation method of the PV/T system under design condition was proposed to analyze the influence of key parameters on the system performance.And the variable condition characteristics of the PV/T system under different structures were compared.Results show that under the design condition,the electrical efficiency of PV/T system with multi and single square-tube is about 15%,and the total system efficiency is more than 78%.With the increase of solar radiation intensity,the temperature of photovoltaic panel and the outlet temperature of fluid increase in these two structures,which increase the total system efficiency subsequently.The electrical efficiency and total system efficiency can be improved by increasing the inlet volume flow rate or reducing the inlet temperature.Under the same operation condition,the total efficiency of single square-tube flat plate PV/T system is 3.1% lower than that of multi square-tube one,and the photovoltaic panel temperature of multi square-tube flat plate PV/T system is 9.72 K lower than that of single square-tube one.Therefore,better comprehensive performance is achieved by multi square-tube flat plate PV/T system.