Development of a one-dimensional system code for the analysis of downward air-water two-phase flow in large vertical pipes
In nuclear thermal-hydraulic system codes, most correlations used for vertical pipes, under downward two-phase flow, have been developed considering small pipes or pool systems. This suggests that there could be uncertainties in applying the correlations to accident scenarios involving large vertica...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2024-01-01
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| Series: | Nuclear Engineering and Technology |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S1738573323003856 |
| _version_ | 1797355256628117504 |
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| author | Donkoan Hwang Soon Ho Kang Nakjun Choi HangJin Jo |
| author_facet | Donkoan Hwang Soon Ho Kang Nakjun Choi HangJin Jo |
| author_sort | Donkoan Hwang |
| collection | DOAJ |
| description | In nuclear thermal-hydraulic system codes, most correlations used for vertical pipes, under downward two-phase flow, have been developed considering small pipes or pool systems. This suggests that there could be uncertainties in applying the correlations to accident scenarios involving large vertical pipes owing to the difference in the characteristics of two-phase flows, or flow conditions, between large and small pipes. In this study, we modified the Multi-dimensional Analysis of Reactor Safety KINS Standard (MARS-KS) code using correlations, such as the drift-flux model and two-phase multiplier, developed in a plant-scale air-inflow experiment conducted for a pipe of diameter 600 mm under downward two-phase flow. The results were then analyzed and compared with those based on previous correlations developed for small pipes and pool conditions. The modified code indicated a good estimation performance in two plant-scale experiments with large pipes. For the siphon-breaking experiment, the maximum errors in water flow for modified and original codes were 2.2% and 30.3%, respectively. For the air-inflow accident experiment, the original code could not predict the trend of frictional pressure gradient in two-phase flow as ⟨jg⟩/⟨j⟩ increased, while the modified MARS-KS code showed a good estimation performance of the gradient with maximum error of 3.5%. |
| first_indexed | 2024-03-08T14:08:38Z |
| format | Article |
| id | doaj.art-09bdd20d95434013ac19ca4e79819691 |
| institution | Directory Open Access Journal |
| issn | 1738-5733 |
| language | English |
| last_indexed | 2024-03-08T14:08:38Z |
| publishDate | 2024-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Nuclear Engineering and Technology |
| spelling | doaj.art-09bdd20d95434013ac19ca4e798196912024-01-15T04:20:41ZengElsevierNuclear Engineering and Technology1738-57332024-01-015611933Development of a one-dimensional system code for the analysis of downward air-water two-phase flow in large vertical pipesDonkoan Hwang0Soon Ho Kang1Nakjun Choi2HangJin Jo3Division of Advanced Nuclear Engineering, POSTECH, Pohang, 790-784, Republic of KoreaKorea Institute of Nuclear Safety (KINS), Daejeon, 305-338, Republic of KoreaDivision of Advanced Nuclear Engineering, POSTECH, Pohang, 790-784, Republic of KoreaDivision of Advanced Nuclear Engineering, POSTECH, Pohang, 790-784, Republic of Korea; Department of Mechanical Engineering, POSTECH, Pohang, 790-784, Republic of Korea; Corresponding author. Division of Advanced Nuclear Engineering Department of Mechanical Engineering POSTECH, Pohang, 790-784, South Korea.In nuclear thermal-hydraulic system codes, most correlations used for vertical pipes, under downward two-phase flow, have been developed considering small pipes or pool systems. This suggests that there could be uncertainties in applying the correlations to accident scenarios involving large vertical pipes owing to the difference in the characteristics of two-phase flows, or flow conditions, between large and small pipes. In this study, we modified the Multi-dimensional Analysis of Reactor Safety KINS Standard (MARS-KS) code using correlations, such as the drift-flux model and two-phase multiplier, developed in a plant-scale air-inflow experiment conducted for a pipe of diameter 600 mm under downward two-phase flow. The results were then analyzed and compared with those based on previous correlations developed for small pipes and pool conditions. The modified code indicated a good estimation performance in two plant-scale experiments with large pipes. For the siphon-breaking experiment, the maximum errors in water flow for modified and original codes were 2.2% and 30.3%, respectively. For the air-inflow accident experiment, the original code could not predict the trend of frictional pressure gradient in two-phase flow as ⟨jg⟩/⟨j⟩ increased, while the modified MARS-KS code showed a good estimation performance of the gradient with maximum error of 3.5%.http://www.sciencedirect.com/science/article/pii/S1738573323003856Thermal-hydraulic system codeFrictional pressure gradient in two-phase flowLarge vertical pipesTwo-phase flowTwo-phase multiplierDrift-flux model |
| spellingShingle | Donkoan Hwang Soon Ho Kang Nakjun Choi HangJin Jo Development of a one-dimensional system code for the analysis of downward air-water two-phase flow in large vertical pipes Nuclear Engineering and Technology Thermal-hydraulic system code Frictional pressure gradient in two-phase flow Large vertical pipes Two-phase flow Two-phase multiplier Drift-flux model |
| title | Development of a one-dimensional system code for the analysis of downward air-water two-phase flow in large vertical pipes |
| title_full | Development of a one-dimensional system code for the analysis of downward air-water two-phase flow in large vertical pipes |
| title_fullStr | Development of a one-dimensional system code for the analysis of downward air-water two-phase flow in large vertical pipes |
| title_full_unstemmed | Development of a one-dimensional system code for the analysis of downward air-water two-phase flow in large vertical pipes |
| title_short | Development of a one-dimensional system code for the analysis of downward air-water two-phase flow in large vertical pipes |
| title_sort | development of a one dimensional system code for the analysis of downward air water two phase flow in large vertical pipes |
| topic | Thermal-hydraulic system code Frictional pressure gradient in two-phase flow Large vertical pipes Two-phase flow Two-phase multiplier Drift-flux model |
| url | http://www.sciencedirect.com/science/article/pii/S1738573323003856 |
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