Open AccessInfluence of void ratio on phase change of thermal energy storage for heat pipe receiver
Author(s) -
Xingmin Gui,
Xiaoguo Song,
Tie Li,
Liang Shan,
Dingsheng Yuan,
Dawei Tang
Publication year - 2015
Publication title -
thermal science/thermal science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.339
H-Index - 43
eISSN - 2334-7163
pISSN - 0354-9836
DOI - 10.2298/tsci130627135x
Subject(s) - phase change material , materials science , thermal energy storage , porosity , void (composites) , void ratio , thermal , heat transfer , phase change , mechanics , thermodynamics , composite material , physics
In this paper, influence of void ratio on phase change of thermal storage unit for heat pipe receiver under microgravity is numerically simulated. Accordingly, mathematical model is set up. A solidification-melting model upon the enthalpy-porosity method is specially provided to deal with phase changes. The liquid fraction distribution of thermal storage unit of heat pipe receiver is shown. The fluctuation of melting ratio in PCM canister is indicated. Numerical results are compared with experimental ones in Japan. The results show that void cavity prevents the process of phase change greatly. PCM melts slowly during sunlight periods and freezes slowly during eclipse periods as void ratio increases. The utility ratio of PCM during both sunlight periods and eclipse periods decreases obviously with the improvement of void ratio. The thermal resistance of void cavity is much higher than that of PCM canister wall. Void cavity prevents the heat transfer between PCM zone and canister wall