采用锯齿型颗粒释放模式的下落式颗粒吸热器的热性能分析

Thermal performance analysis of a falling particle receiver using a zigzag particle release pattern

针对塔式太阳能热发电系统中下落式颗粒吸热器辐射损失大、热效率低的问题,研究了一种改善吸热器中颗粒帘幕光热转换特性的锯齿型颗粒释放模式以提高吸热器热性能。首先,针对塔式系统中的光热耦合过程建立了一个耦合蒙特卡洛光线追迹法和有限体积法的数值集成模型;然后,基于此模型分析了采用不同振幅和波长的锯齿型颗粒释放模式对下落式颗粒吸热器热性能的影响。结果表明:当波长为0.2 m且振幅大于0.3 m时,锯齿型颗粒释放模式可以提高吸热器热性能。最优锯齿型模式的波长为0.2 m、振幅为0.4 m,其吸热器效率相较于传统的直线型模式提高了0.91%。

In order to improve the problem of high radiation loss and low thermal efficiency of the falling particle receiv-er in the solar power tower system,a zig-zag particle release pattern,which can improve the optical-thermal conversion characteristics of particle curtain of the receiver,is investigated in this paper to improve the thermal performance of the receiver.A numerical integrated model coupling Monte Carlo ray tracing method and finite volume method is firstly es-tablished for the optical-thermal coupling process in the solar power tower system;and based on this model,the thermal performance of the falling particle receiver with zigzag particle release pattern using different geometric factors(ampli-tude and wavelength)is analyzed.The results show that the zigzag particle release pattern can improve the receiver per-formance when the wavelength is 0.2 m and the amplitude is greater than 0.3 m.The optimal zigzag pattern with a wave-length of 0.2 m and an amplitude of 0.4 m improved the receiver efficiency by 0.91%compared with the conventional straight-line pattern.