Exergy analyses of heat pipe evacuated tube collector with heat shield

被引：0
|
作者：
Zhong S. [1 ]
Pei G. [1 ]
Wang Q. [1 ]
Yang H. [1 ]
机构：
[1] Department of Thermal Science and Energy Engineering, University of Science and Technology of China, Hefei
来源：
Taiyangneng Xuebao/Acta Energiae Solaris Sinica | 2021年 / 42卷 / 05期
关键词：
Efficiency; Exergy; Radiation shielding; Solar collector; Vacuum tube;
D O I：
10.19912/j.0254-0096.tynxb.2019-0114
中图分类号：
学科分类号：
摘要：
The study used an exergy analysis model to investigate two different heat pipe evacuated tube collectors (HPETCs) with and without a heat shield. The heat loss and exergy analysis models of HPETCs were established, and verified by experimental results. The exergy efficiencies of the two different HPETCs were compared. In addition, the effects of the solar irradiance and operating temperature on the exergy efficiency of HPETC with a heat shield were also explored. The results showed that the inserted heat shield in the heat pipe evacuated tube can effectively enhance the exergy efficiency of the HPETC. When the solar irradiance is 800 W/m2, the absolute exergy efficiency of the HPETC with a heat shield can increase by 0.8% at the operating temperature of 80℃ and 4.7% at the operating temperature of 80℃ compared with the HPETC without a heat shield. In the case of the solar irradiance of 800 W/m2, furthermore, the HPETC with a heat shield can increase the maximum exergy efficiency from 14.6% to 17.5%, and the corresponding temperature increases from 135℃ to 156℃. The reason for the effective enhancements of the exergy efficiency in the HPETC with a heat shield is that the heat shield plays an important role in reducing the irreversible heat losses of the glass tube and absorber plate. The parametric analyses on the HPETC with a heat shield showed that the exergy efficiency and the operating temperature corresponding to maximum exergy efficiency get higher with increasing solar irradiance, and the effect of solar irradiance on the exergy efficiency is more significant at higher temperature. © 2021, Solar Energy Periodical Office Co., Ltd. All right reserved.
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页码：295 / 301
页数：6
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