Understanding triggering mechanisms for critical heat flux in pool boiling based on direct numerical simulations
© 2020 Boiling is a ubiquitous process in many applications including power generation, desalination, and high-heat flux electronic cooling. At the same time, boiling is a complicated physical process involving hydrodynamics and interfacial heat and mass transfer on multiple scales. One of the key l...
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | English |
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Elsevier BV
2022
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| Online Access: | https://hdl.handle.net/1721.1/142060 |
| _version_ | 1811088730710081536 |
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| author | Gong, Shuai Zhang, Lenan Cheng, Ping Wang, Evelyn N |
| author2 | Massachusetts Institute of Technology. Department of Mechanical Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Mechanical Engineering Gong, Shuai Zhang, Lenan Cheng, Ping Wang, Evelyn N |
| author_sort | Gong, Shuai |
| collection | MIT |
| description | © 2020 Boiling is a ubiquitous process in many applications including power generation, desalination, and high-heat flux electronic cooling. At the same time, boiling is a complicated physical process involving hydrodynamics and interfacial heat and mass transfer on multiple scales. One of the key limiting factors of boiling is the critical heat flux (CHF), beyond which a vapor blanket forms on the heating surface and catastrophic device burnout occurs. Yet, detailed understanding of the mechanism that triggers CHF remains elusive. In this paper, we elucidate the CHF mechanism by studying the evolution of wet/dry region on the heater surface using lattice Boltzmann simulations. We incorporate the equation of state for real gases in the liquid-vapor phase change model for direct numerical simulations of the CHF phenomenon. The results of this framework clarify the difference between the triggering mechanism of CHF and film boiling by analyzing the pool boiling curve. We demonstrate that the heat flux of the wet region on the heater surface increases while the wet area fraction decreases with superheat, leading to the CHF. We show that a vapor recoil force due to the interfacial heat and mass transfer plays an important role for the evolution of wet area fraction and therefore contributes to the occurrence of a second transition regime and CHF. Compared with previous CHF models which treat CHF as an isolated point on the boiling curve, this work elucidates the triggering mechanism of CHF from a perspective of the dynamic evolution of the wet/dry region with increasing superheat, which could potentially serve as a guideline for future CHF enhancement designs. |
| first_indexed | 2024-09-23T14:06:38Z |
| format | Article |
| id | mit-1721.1/142060 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T14:06:38Z |
| publishDate | 2022 |
| publisher | Elsevier BV |
| record_format | dspace |
| spelling | mit-1721.1/1420602023-01-27T20:48:37Z Understanding triggering mechanisms for critical heat flux in pool boiling based on direct numerical simulations Gong, Shuai Zhang, Lenan Cheng, Ping Wang, Evelyn N Massachusetts Institute of Technology. Department of Mechanical Engineering © 2020 Boiling is a ubiquitous process in many applications including power generation, desalination, and high-heat flux electronic cooling. At the same time, boiling is a complicated physical process involving hydrodynamics and interfacial heat and mass transfer on multiple scales. One of the key limiting factors of boiling is the critical heat flux (CHF), beyond which a vapor blanket forms on the heating surface and catastrophic device burnout occurs. Yet, detailed understanding of the mechanism that triggers CHF remains elusive. In this paper, we elucidate the CHF mechanism by studying the evolution of wet/dry region on the heater surface using lattice Boltzmann simulations. We incorporate the equation of state for real gases in the liquid-vapor phase change model for direct numerical simulations of the CHF phenomenon. The results of this framework clarify the difference between the triggering mechanism of CHF and film boiling by analyzing the pool boiling curve. We demonstrate that the heat flux of the wet region on the heater surface increases while the wet area fraction decreases with superheat, leading to the CHF. We show that a vapor recoil force due to the interfacial heat and mass transfer plays an important role for the evolution of wet area fraction and therefore contributes to the occurrence of a second transition regime and CHF. Compared with previous CHF models which treat CHF as an isolated point on the boiling curve, this work elucidates the triggering mechanism of CHF from a perspective of the dynamic evolution of the wet/dry region with increasing superheat, which could potentially serve as a guideline for future CHF enhancement designs. 2022-04-25T16:55:01Z 2022-04-25T16:55:01Z 2020 2022-04-25T16:49:42Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/142060 Gong, Shuai, Zhang, Lenan, Cheng, Ping and Wang, Evelyn N. 2020. "Understanding triggering mechanisms for critical heat flux in pool boiling based on direct numerical simulations." International Journal of Heat and Mass Transfer, 163. en 10.1016/J.IJHEATMASSTRANSFER.2020.120546 International Journal of Heat and Mass Transfer Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Elsevier BV Prof. Evelyn Wang |
| spellingShingle | Gong, Shuai Zhang, Lenan Cheng, Ping Wang, Evelyn N Understanding triggering mechanisms for critical heat flux in pool boiling based on direct numerical simulations |
| title | Understanding triggering mechanisms for critical heat flux in pool boiling based on direct numerical simulations |
| title_full | Understanding triggering mechanisms for critical heat flux in pool boiling based on direct numerical simulations |
| title_fullStr | Understanding triggering mechanisms for critical heat flux in pool boiling based on direct numerical simulations |
| title_full_unstemmed | Understanding triggering mechanisms for critical heat flux in pool boiling based on direct numerical simulations |
| title_short | Understanding triggering mechanisms for critical heat flux in pool boiling based on direct numerical simulations |
| title_sort | understanding triggering mechanisms for critical heat flux in pool boiling based on direct numerical simulations |
| url | https://hdl.handle.net/1721.1/142060 |
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