摘要
为了研究石墨蓄热对太阳能集热管内流动沸腾传热特性的影响,采用对比实验方法,通过改变热流密度设计4种不同的加热阶段,以石墨蓄热对集热管出口蒸汽温度、集热管均温性的改善为依据对石墨蓄热集热管性能进行评价,并重点分析石墨蓄热对集热管内流动沸腾不稳定性特征与管内换热系数的影响.实验结果表明,石墨蓄热导致辐照(热流密度)突降时集热管出口蒸汽温度降低时间延长了30.0%.与此同时,石墨蓄热对集热管轴向和径向温差均有明显的改善.在高热流密度条件下,集热管均温性的改善有效地抑制管内流动沸腾传热不稳定性,使得集热管的平均换热系数提高了7.23%.
A comparative experiment was conducted to investigate the effects of heat storage of graphite on flow boiling heat transfer characteristics in solar receiver. Improvement of thermal performance of receiver was verified by the outlet temperature and the isothermal performance of receiver by setting a four - stage heating process with different heat flux. The effects of thermal energy storage of graphite on flow instability and heat transfer were analyzed. Results showed that the thermal energy storage of graphite resulted in a time prolongation of outlet temperature decline by 30. 0% when a sudden drop of solar radiation （or heat flux） happened. Heat storage of graphite improved the isothermality of receiver in both radius and axis direction. The isothermality improvement effectively restrained the flow boiling instabilities in receiver for the case of higher heat flux condition. A heat transfer coefficient enhancement by was obtained 7. 23%.
出处
《浙江大学学报（工学版）》
EI
CAS
CSCD
北大核心
2016年第11期2087-2093,共7页
Journal of Zhejiang University：Engineering Science
基金
国家自然科学青年基金资助项目(51406177)
中国博士后科学基金资助项目(2014M551734
2015T80613)
