Experimental study on single- and two-phase flow behaviors within porous particle beds

• Published in: Nuclear engineering and technology Vol. 55; no. 3; pp. 1105 - 1117
• Main Authors: Jong Seok Oh, Sang Mo An, Hwan Yeol Kim, Dong Eok Kim
• Format: Journal Article
• Language: Korean
• Published: 2023
• Subjects: Severe accident; Two-phase flow; Counter-current flooding limit; Porous particle bed
• ISSN: 1738-5733; 2234-358X

In this study, the pressure drop behavior of single- and two-phase flows of air and water through the porous beds filled with uniform and non-uniform sized spherical particles was examined. The pressure drop data in the single-phase flow experiments for the uniform particle beds agreed well with the original Ergun correlation. The results from the two-phase flow experiments were analyzed using numerical results based on three types of previous models. In the experiments for the uniform particle beds, the data on the two-phase pressure drop clearly showed the effect of the flow regime transition with a variation in the gas flow rate under stagnant liquid condition. The numerical analyses indicated that the predictability of the previous models for the experimental data relied mainly on the sub-models of the flow regime transitions and interfacial drag. In the experiments for the non-uniform particle beds, the two-phase pressure loss could be predicted well with numerical calculations based on the effective particle diameter. However, the previous models failed to accurately predict the counter-current flooding limit observed in the experiments. Finally, we propose a relation of falling liquid velocity into the particle bed by gravity to appropriately simulate the CCFL phenomenon.