Investigation on Regime of Vertical Downward Submerged Steam-Direct Contact Condensation
Direct contact condensation affects the performance of pressure suppression system of nuclear reactor. Since the heat and mass transfer varies with the condensation regimes as well as steam-water interface shapes, the identification and classification of the condensation regimes are important. The e...
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| Format: | Article |
| Language: | English |
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Editorial Board of Atomic Energy Science and Technology
2022-08-01
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| Series: | Yuanzineng kexue jishu |
| Subjects: | |
| Online Access: | https://www.aest.org.cn/CN/10.7538/yzk.2022.youxian.0397 |
| _version_ | 1798015710287364096 |
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| author | LIU Haiqiang;GUO Zhangpeng;QIU Meiming;WANG Shengfei;NIU Fenglei;HUANG Yanping |
| author_facet | LIU Haiqiang;GUO Zhangpeng;QIU Meiming;WANG Shengfei;NIU Fenglei;HUANG Yanping |
| author_sort | LIU Haiqiang;GUO Zhangpeng;QIU Meiming;WANG Shengfei;NIU Fenglei;HUANG Yanping |
| collection | DOAJ |
| description | Direct contact condensation affects the performance of pressure suppression system of nuclear reactor. Since the heat and mass transfer varies with the condensation regimes as well as steam-water interface shapes, the identification and classification of the condensation regimes are important. The experiment of steam direct contact condensation was carried out and the corresponding condensation regimes were studied. Specifically, the experiment was studied by injecting steam vertically into a wet well with subcooled water. The physical process of steam condensation phenomenon with varying undercooling degree of wet well was recorded by high-speed camera. According to the location of the steam-water interface and the shape of the steam bubble, the four condensation regimes were studied, namely internal chugging, external necking, spheroidal upward bubble and T-shaped upward bubble. Besides, it is found that thermal stratification occurs in the wet well at low steam mass flux, the influence of each condensation regime on the thermal stratification of wet well was studied. The experimental results show that the internal chugging and external necking cause a large downward circulation of subcooled water, which enhance the flow mixing around the discharge tube and the bottom of the wet well. Consequently, the thermal stratification phenomenon does not happen in those condensation regimes. However, the regimes like spheroidal upward bubble and T-shaped upward bubble cause the upward circulation of subcooled water in wet well, which cause the thermal stratification. The critical Richardson number (Ri) determines the condensation regimes. Furthermore, when the Ri is smaller than 1, the condensation regime is external necking. Besides, when the Ri is greater than 1, the condensation regimes are spheroidal upward bubble and T-shaped upward bubble. |
| first_indexed | 2024-04-11T15:39:07Z |
| format | Article |
| id | doaj.art-5eb06733fb0e433c9b2ede139f0f74bd |
| institution | Directory Open Access Journal |
| issn | 1000-6931 |
| language | English |
| last_indexed | 2024-04-11T15:39:07Z |
| publishDate | 2022-08-01 |
| publisher | Editorial Board of Atomic Energy Science and Technology |
| record_format | Article |
| series | Yuanzineng kexue jishu |
| spelling | doaj.art-5eb06733fb0e433c9b2ede139f0f74bd2022-12-22T04:15:53ZengEditorial Board of Atomic Energy Science and TechnologyYuanzineng kexue jishu1000-69312022-08-0156815591565Investigation on Regime of Vertical Downward Submerged Steam-Direct Contact CondensationLIU Haiqiang;GUO Zhangpeng;QIU Meiming;WANG Shengfei;NIU Fenglei;HUANG Yanping 0Beijing Key Laboratory of Passive Safety Technology for Nuclear Energy, North China Electric Power University, Beijing 102206, China；CNNC Key Laboratory on Nuclear Reactor Thermal Hydraulics Technology, Nuclear Power Institute of China, Chengdu 610041, ChinaDirect contact condensation affects the performance of pressure suppression system of nuclear reactor. Since the heat and mass transfer varies with the condensation regimes as well as steam-water interface shapes, the identification and classification of the condensation regimes are important. The experiment of steam direct contact condensation was carried out and the corresponding condensation regimes were studied. Specifically, the experiment was studied by injecting steam vertically into a wet well with subcooled water. The physical process of steam condensation phenomenon with varying undercooling degree of wet well was recorded by high-speed camera. According to the location of the steam-water interface and the shape of the steam bubble, the four condensation regimes were studied, namely internal chugging, external necking, spheroidal upward bubble and T-shaped upward bubble. Besides, it is found that thermal stratification occurs in the wet well at low steam mass flux, the influence of each condensation regime on the thermal stratification of wet well was studied. The experimental results show that the internal chugging and external necking cause a large downward circulation of subcooled water, which enhance the flow mixing around the discharge tube and the bottom of the wet well. Consequently, the thermal stratification phenomenon does not happen in those condensation regimes. However, the regimes like spheroidal upward bubble and T-shaped upward bubble cause the upward circulation of subcooled water in wet well, which cause the thermal stratification. The critical Richardson number (Ri) determines the condensation regimes. Furthermore, when the Ri is smaller than 1, the condensation regime is external necking. Besides, when the Ri is greater than 1, the condensation regimes are spheroidal upward bubble and T-shaped upward bubble.https://www.aest.org.cn/CN/10.7538/yzk.2022.youxian.0397direct contact condensationvertical downwardcondensation regimerichardson number |
| spellingShingle | LIU Haiqiang;GUO Zhangpeng;QIU Meiming;WANG Shengfei;NIU Fenglei;HUANG Yanping Investigation on Regime of Vertical Downward Submerged Steam-Direct Contact Condensation Yuanzineng kexue jishu direct contact condensation vertical downward condensation regime richardson number |
| title | Investigation on Regime of Vertical Downward Submerged Steam-Direct Contact Condensation |
| title_full | Investigation on Regime of Vertical Downward Submerged Steam-Direct Contact Condensation |
| title_fullStr | Investigation on Regime of Vertical Downward Submerged Steam-Direct Contact Condensation |
| title_full_unstemmed | Investigation on Regime of Vertical Downward Submerged Steam-Direct Contact Condensation |
| title_short | Investigation on Regime of Vertical Downward Submerged Steam-Direct Contact Condensation |
| title_sort | investigation on regime of vertical downward submerged steam direct contact condensation |
| topic | direct contact condensation vertical downward condensation regime richardson number |
| url | https://www.aest.org.cn/CN/10.7538/yzk.2022.youxian.0397 |
| work_keys_str_mv | AT liuhaiqiangguozhangpengqiumeimingwangshengfeiniufengleihuangyanping investigationonregimeofverticaldownwardsubmergedsteamdirectcontactcondensation |