Wall heat transfer in gas-fired furnaces: Effect of radiation modelling
The purpose of this work is to study heat transfer to cooled walls in a MW-scale laboratory furnace with a dominating thermal radiation component. Experiment is performed in a specially designed combustion chamber with segmental water-cooled walls and profile of absorbed heat flux is measured along...
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| Format: | Article |
| Language: | English |
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University of West Bohemia
2015-06-01
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| Series: | Applied and Computational Mechanics |
| Subjects: | |
| Online Access: | http://www.kme.zcu.cz/acm/acm/article/view/276/322 |
| _version_ | 1819018464133644288 |
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| author | Vondál J. Hájek J. |
| author_facet | Vondál J. Hájek J. |
| author_sort | Vondál J. |
| collection | DOAJ |
| description | The purpose of this work is to study heat transfer to cooled walls in a MW-scale laboratory furnace with a dominating thermal radiation component. Experiment is performed in a specially designed combustion chamber with segmental water-cooled walls and profile of absorbed heat flux is measured along the flame. Non-premixed natural gas flame is stabilized by a guide-vane swirler. The unsteady governing equations of turbulent flow are solved by a finite-volume code with a two-equation k-ε realizable turbulence model, a combination of first-order and second-order upwind schemes and implicit time integration. The coupling of pressure with velocity is treated by SIMPLE (semi-implicit method for pressure-linked equations) algorithm. Radiative heat transfer as the main heat transfer method is modelled with special care by discrete ordinates method and gas absorption coefficient is calculated by two alternatives of WSGGM (weighted sum of grey gases model). The predicted total heat transfer rate is found to depend strongly on method chosen for the computation of mean beam length. The results of numerical simulations show that overall heat transfer in a process furnace can be successfully predicted, while heat flux profile along the flame is more difficult to predict accurately. Good engineering accuracy is nevertheless achievable with reasonable computational resources. The trend of deviations is reported, which is useful for the interpretation of practical predictions of process furnaces (fired heaters). |
| first_indexed | 2024-12-21T03:19:50Z |
| format | Article |
| id | doaj.art-726cc1873da9467cb2c78a711d9f7fbf |
| institution | Directory Open Access Journal |
| issn | 1802-680X 2336-1182 |
| language | English |
| last_indexed | 2024-12-21T03:19:50Z |
| publishDate | 2015-06-01 |
| publisher | University of West Bohemia |
| record_format | Article |
| series | Applied and Computational Mechanics |
| spelling | doaj.art-726cc1873da9467cb2c78a711d9f7fbf2022-12-21T19:17:43ZengUniversity of West BohemiaApplied and Computational Mechanics1802-680X2336-11822015-06-01916778Wall heat transfer in gas-fired furnaces: Effect of radiation modellingVondál J.0Hájek J.1Brno University of Technology, Faculty of Mechanical Engineering, Brno, Czech RepublicBrno University of Technology, Faculty of Mechanical Engineering, Brno, Czech RepublicThe purpose of this work is to study heat transfer to cooled walls in a MW-scale laboratory furnace with a dominating thermal radiation component. Experiment is performed in a specially designed combustion chamber with segmental water-cooled walls and profile of absorbed heat flux is measured along the flame. Non-premixed natural gas flame is stabilized by a guide-vane swirler. The unsteady governing equations of turbulent flow are solved by a finite-volume code with a two-equation k-ε realizable turbulence model, a combination of first-order and second-order upwind schemes and implicit time integration. The coupling of pressure with velocity is treated by SIMPLE (semi-implicit method for pressure-linked equations) algorithm. Radiative heat transfer as the main heat transfer method is modelled with special care by discrete ordinates method and gas absorption coefficient is calculated by two alternatives of WSGGM (weighted sum of grey gases model). The predicted total heat transfer rate is found to depend strongly on method chosen for the computation of mean beam length. The results of numerical simulations show that overall heat transfer in a process furnace can be successfully predicted, while heat flux profile along the flame is more difficult to predict accurately. Good engineering accuracy is nevertheless achievable with reasonable computational resources. The trend of deviations is reported, which is useful for the interpretation of practical predictions of process furnaces (fired heaters).http://www.kme.zcu.cz/acm/acm/article/view/276/322gas combustionwall heat fluxswirling diffusion flameradiative heat transfernumerical modelling |
| spellingShingle | Vondál J. Hájek J. Wall heat transfer in gas-fired furnaces: Effect of radiation modelling Applied and Computational Mechanics gas combustion wall heat flux swirling diffusion flame radiative heat transfer numerical modelling |
| title | Wall heat transfer in gas-fired furnaces: Effect of radiation modelling |
| title_full | Wall heat transfer in gas-fired furnaces: Effect of radiation modelling |
| title_fullStr | Wall heat transfer in gas-fired furnaces: Effect of radiation modelling |
| title_full_unstemmed | Wall heat transfer in gas-fired furnaces: Effect of radiation modelling |
| title_short | Wall heat transfer in gas-fired furnaces: Effect of radiation modelling |
| title_sort | wall heat transfer in gas fired furnaces effect of radiation modelling |
| topic | gas combustion wall heat flux swirling diffusion flame radiative heat transfer numerical modelling |
| url | http://www.kme.zcu.cz/acm/acm/article/view/276/322 |
| work_keys_str_mv | AT vondalj wallheattransferingasfiredfurnaceseffectofradiationmodelling AT hajekj wallheattransferingasfiredfurnaceseffectofradiationmodelling |