东南大学学报（英文版）2016，Vol.32Issue(4)：489-495,7.DOI:10.3969/j.issn.1003-7985.2016.04.016
全玻璃真空管太阳能集热器流动换热的试验和数值模拟
Experiment and numerical simulation on flow and heat transfer in all-glass evacuated tube solar collectors
摘要
Abstract
The experimental study of natural convection in all-glass evacuated tube solar collectors is performed through the experimental platform of the solar-assisted fuel cell system. The experimental facility includes solar collectors with different length and diameter tubes, different coating materials, and with/without guide plates, respectively. Three-dimensional mathematical models on natural and forced convections in the solar collectors are established and the experimental data is validated by field synergy and entransy principles. The results of natural convection show that the water temperature increases and thermal efficiency decreases gradually with the evacuated tube length. The thermal efficiency increases when absorption rates increase from 0. 95 to 1. 0 and emission rates decrease from 0. 16 to 0. 06. The thermal efficiency of solar collectors is increased after being equipped with the guide plate, which is attributed to the disappearance of the mixed flow and the enhancement of the heat transfer at the bottom of the evacuated tube. The results of forced convertion indicate that the Reynolds, Nusselt and entransy increments of the horizontal double collectors are higher than those of the vertical single collector while the entransy dissipation is lower than that of the vertical single collector. It is concluded that the solar collectors with guide plates are suitable for natural convection while the double horizontal collectors are suitable for forced convection in the thermal field of solar-assisted fuel cell systems with low and medium temperatures.关键词
全玻璃真空管太阳能集热器/太阳能耦合燃料电池/场协同/火积耗散Key words
all-glass evacuated tube solar collectors/the solar-assisted fuel cells/field synergy principle/entransy dissipation分类
能源科技引用本文复制引用
张涛,韩吉田,陈常念,孔令健,刘洋..全玻璃真空管太阳能集热器流动换热的试验和数值模拟[J].东南大学学报（英文版）,2016,32(4):489-495,7.基金项目
The National Natural Science Foundation of China ( No.51376110,51541604), the Major International ( Regional) Joint Research Project of the National Natural Science Foundation of China ( No.61320106011) （ No.51376110,51541604）
