线性菲涅尔式太阳能聚光器传热及能流均匀化研究
Linear Fresnel Solar Concentrator Heat Transfer and Energy Flow Homogenization Research

对线性菲涅尔式太阳能聚光器的传热性能进行研究，在该系统下建立传热模型并对吸热管壁面温度、热量损失随传热介质对流换热系数上升时的变化规律进行研究。研究结果表明：当辐射到吸热管表面的能流密度恒定时，随着吸热管内传热介质温度上升和换热系数增加，集热管内壁温度逐渐下降并达到极值，如果继续采用强化传热的方法来降低系统热损，会使得效果逐渐减弱；针对吸热管周向能流非均匀问题，本文提出了一种基于粒子群算法的优化方法，通过改变主镜场中一次反射镜的瞄准点，使得接收器表面能流分布标准偏差达到最小，从而使得吸热管周向的能流分布更加均匀。通过优化使得当系统光学效率达到79.75%时，吸热管上半部分的能流分布由36.6%上升到了39.5%。以上研究结果将为线性菲涅尔式太阳能集热器的优化设计和应用提供理论支撑。
The heat transfer performance of the linear Fresnel solar concentrator is studied, a heat transfer model is established under this system and the variation law of the wall temperature and heat loss of the collector tube with the increase of the convective heat transfer coefficient of the heat transfer medium is studied. The research results show that when the energy flux density radiated to the surface of the collector tube is constant, as the temperature of the heat transfer medium in the collector tube increases and the heat transfer coefficient increases, the temperature of the inner wall of the collector tube gradually decreases and reaches the extreme value. If the method of enhancing heat transfer is continued to reduce the heat loss of the system, the effect will gradually weaken. Aiming at the problem of the non-uniformity of the circumferential energy flow of the collector tube, an optimization method based on particle swarm optimization is proposed. By changing the aiming point of the primary mirror in the primary mirror field, the standard deviation of the energy flow distribution on the receiver surface can be minimized, so that the energy flow distribution in the circumferential direction of the collector tube is more uniform. Through optimization, when the optical efficiency of the system reaches 79.75%, the energy flow distribution in the upper half of the heat absorption tube increases from 36.6% to 39.5%. The above research results will provide theoretical support for the optimal design and application of linear Fresnel solar collectors.