两级反射线性菲涅尔中高温集热系统热性能

Thermal behavior of two-stage linear Fresnel reflector concentrator

针对复合抛物面集热器(compound parabolic collector,CPC)作为二级反射器和单层玻璃盖板的反射式线性菲涅尔中高温集热系统(linear Fresnel reflector concentrator,LFRC)的集热性能,基于稳态传热平衡原理,建立了集热系统稳态传热模型。系统地研究了风速、温度、太阳辐照度、聚光比、传热工质流速和流体进口温度等参数对接收器集热性能的影响,并给出了沿接收器管长的温度和能量分布情况。数值模拟结果表明:对于该集热系统,太阳辐照度、聚光比和工质进口温度是影响集热性能的关键影响因素,最高可达到72%,风速和环境温度对集热效率影响较小。因此增加接收器的长度能够很好地提高集热温度。

The thermal performance of linear Fresnel reflector concentrator（LFRC） with secondary compound parabolic collector （CPC） reflector and a single-layer glass cover were studied. A heat transfer model of LFRC system in steady state had been established according to energy balance principle. Based on this model, the influence of wind speed, en- vironment temperature, solar radiation intensity, concentration ratio, working fluid speed and inlet temperature etc. on concentrator thermal performance had been analyzed systematically, and the temperature and energy distribution along the receiver tube were also given. The results showed that through the numerical simulation, the solar radiation intensi- ty, concentration ratio and inlet temperature were recognized as the key factors affecting the thermal performance of this targeted of LFRC, which could reach 72%, while the environment factors such as wind and temperature had less influ- ences. So it was helpful to increase the length of the receiver to improve the thermal performance.