Enhanced heat transfer in a parabolic trough solar receiver by inserting rods and using molten salt as heat transfer fluid
Enhanced heat transfer in a parabolic trough solar receiver by inserting rods and using molten salt as heat transfer fluid
复制标题
通过插入棒并使用熔盐作为传热流体来增强抛物面槽式太阳能接收器中的传热
DOI：
10.1016/j.apenergy.2018.03.091
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发表时间：
2018
期刊：
影响因子：
11.2
通讯作者：
Ding Yulong
中科院分区：
文献类型：
--
作者：
Chang Chun;Sciacovelli Adriano;Wu Zhiyong;Li Xin;Li Yongliang;Zhao Mingzhi;Deng Jie;Wang Zhifeng;Ding Yulong
为了提高槽式抛物面接收器的可靠性和整体传热性能，引入同心杆和偏心杆作为湍流器，分析了槽式抛物面接收器内熔盐的流动和对流换热特性。开发了三维模型，并通过实验结果和经验方程进行了验证。新型抛物线槽集热器提供了高度不均匀的热通量。结果表明，同心嵌棒和偏心嵌棒均能有效提高传热性能。对于带有同心杆插入件的抛物面槽式接收器，随着无量纲直径B的增加，归一化努塞尔数约为普通抛物面槽式接收器的1.10至7.42倍。性能评价标准无法合理评价Bgrowth对综合传热性能的影响。通过引入综合性能因子，可以给出合理的解，结果表明，当Bi大于0.8时，综合性能因子随着雷诺数的增加而显着减小。随着B的增加，同心杆插入式抛物面槽式接收器在一定雷诺数下的综合性能因数减小。对于偏心杆插入件，在一定的无量纲偏心距H下，性能评价标准和综合性能因子随着雷诺数的增加而减小。当Hi为0.8时，性能评估标准从普通抛物面槽式接收器的大约1.84倍下降到1.68倍。而且在一定雷诺数下，随着BandH的增加，温度分布可以更加均匀，吸热管的最高温度也可以显着降低，这有助于减少热变形，提高抛物槽式接收器的可靠性。
With the aim to enhance the reliability and overall heat transfer performance of a parabolic trough receiver, concentric rod and eccentric rod are introduced as turbulators, and the flow and convective heat transfer characteristics of molten salt in a parabolic trough receiver are analyzed. A three-dimensional model was developed and has been validated with experimental results and empirical equations. Highly non-uniform heat flux was provided by a novel parabolic trough collector. The result shows that both concentric rod insert and eccentric rod insert can enhance the heat transfer performance effectively. For a parabolic trough receiver with a concentric rod insert, with the increasing of dimensionless diameterB, the normalized Nusselt number is about 1.10 to 7.42 times over a plain parabolic trough receiver. The performance evaluation criteria can't reasonably evaluate the effect ofBgrowth on the comprehensive heat transfer performance. By introducing integrated performance factor, it can give a reasonable solution, and it shows that the integrated performance factor has a significance decreases with the increase of Reynolds number whenBis larger than 0.8. WithBincreasing, the integrated performance factor of parabolic trough receiver with concentric rod insert decreasing under a certain Reynolds number. For an eccentric rod insert, the performance evaluation criteria and the integrated performance factor decrease with the increasing of Reynolds number under a certain dimensionless eccentricityH. The performance evaluation criteria decreases from about 1.84 to 1.68 times over a plain parabolic trough receiver whenHis 0.8. Moreover, the temperature distribution can be uniformed and the maximum temperature on the absorber tube also can be remarkably reduced with the increasing ofBandHunder a certain Reynolds number, which helps to reduce the thermal deflection and increase the reliability for a parabolic trough receiver.