Numerical Investigation of Gas Flow Distribution and Thermal Mixing in Helically Coiled Tube Bundle

• Published in: Journal of nuclear science and technology 2008-07, Vol.45 (7), p.704-711
• Main Authors: DUAN, Ri-Qiang, JIANG, Sheng-Yao
• Format: Article
• Language: English
• Subjects: Applied sciences; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fission nuclear power plants; gas flow distribution; helically coiled tube bundle; Installations for energy generation and conversion: thermal and electrical energy; steam generator; thermal mixing
• ISSN: 0022-3131; 1881-1248
• DOI: 10.1080/18811248.2008.9711470

In this study, we carried out the numerical simulation of gas flow across a helically coiled tube bundle, which is fitted in the annular space between a central spine and an outer casing. We focused on the effect of clearances at the inner and outer radial boundaries on the gas flow distribution and thermal mixing in the tube bundle. The conservation equations of mass, momentum and energy were numerically solved by computational fluid dynamics. It was demonstrated from the numerical simulation results that (i) the gas flow distribution in the tube bundle is very sensitive to clearances at the inner and outer radial boundaries, and even a very small variation of clearances would lead to a considerable change in the average velocity profile, which correspondingly leads to a great deviation of the gas flow distribution away from the original one; (ii) the clearance effect on thermal mixing is not as strong as that on gas flow distribution;(iii) the Reynolds number has little effect on the gas flow distribution and thermal mixing, the latter of which is in agreement with the results of Achenbach experiments.