Experimental Research on the Flow and Heat Transfer Characteristics of Subcritical and Supercritical Water in the Vertical Upward Smooth and Rifled Tubes

Autor: Xiaocheng Du, Weiteng Li, Xirong Zhang, Jingrong Chen, Tingyu Chen, Dong Yang
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Energies, Vol 15, Iss 21, p 7941 (2022)
Druh dokumentu: article
ISSN: 1996-1073
DOI: 10.3390/en15217941
Popis: Experiments were conducted to investigate the heat transfer and flow characteristics of the vertical upward smooth and rifled tubes from subcritical to supercritical pressure. The distributions of wall temperature and heat transfer coefficient (HTC) were obtained, and the HTC correlations and friction resistance coefficient correlations were fitted with experimental data. In addition, the influences of heat flux and type of tube on heat transfer performance were analyzed. The research shows that heat flux has different influences on the heat transfer characteristics under different pressures. The increase in heat flux improves the heat transfer characteristics in the nucleate boiling region, yet it leads to the advance in heat transfer deterioration. However, for supercritical water, the increase in heat flux reduces the heat transfer ability. In addition, using the rifled tube not only improves the heat transfer performance, but also inhibits the occurrence of heat transfer deterioration. The fitted correlations have great predictive ability for the heat transfer coefficient and friction resistance coefficient, and the average relative fitting errors are limited to 20%.
Databáze: Directory of Open Access Journals
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