Heat Transfer Analysis for Combustion under Low-Gradient Conditions in a Small-Scale Industrial Energy Systems
The issue of maintaining low-gradient combustion in the conditions of high heat extraction has been investigated numerically in this work. The analyses include the application of a convective boundary condition at the wall (with estimated boiling heat transfer coefficient); analysis of the Internal...
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| Format: | Article |
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MDPI AG
2023-12-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/17/1/186 |
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| author | Mieszko Tokarski Rafał Buczyński |
| author_facet | Mieszko Tokarski Rafał Buczyński |
| author_sort | Mieszko Tokarski |
| collection | DOAJ |
| description | The issue of maintaining low-gradient combustion in the conditions of high heat extraction has been investigated numerically in this work. The analyses include the application of a convective boundary condition at the wall (with estimated boiling heat transfer coefficient); analysis of the Internal Recirculation Device’s impact on combustion products and heat transfer under low-gradient conditions; and comparison of both traditional and low-gradient combustion modes. It was shown that the Internal Recirculation Device material and geometry has a significant impact on the nitrogen oxide (NO<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>x</mi></msub></semantics></math></inline-formula>) formation mechanism, as NO<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula> emission becomes predominant and can rise up to several hundreds ppm. What is more, along with decrease in thermal resistance of the IRD, CO emissions also increase rapidly, even achieving over 2000 ppm. Additionally, the convective heat transfer rate decreased by about 25% after switching from traditional to low-gradient combustion, whereas the radiative mechanism increased by ≈40% compared to traditional mode. It should also be mentioned that the low-gradient combustion applied in this work achieved approximately 10% higher efficiency than conventional combustion. |
| first_indexed | 2024-03-08T15:08:31Z |
| format | Article |
| id | doaj.art-803831056a474ecb93d0a0aec666cdf0 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-08T15:08:31Z |
| publishDate | 2023-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-803831056a474ecb93d0a0aec666cdf02024-01-10T14:56:09ZengMDPI AGEnergies1996-10732023-12-0117118610.3390/en17010186Heat Transfer Analysis for Combustion under Low-Gradient Conditions in a Small-Scale Industrial Energy SystemsMieszko Tokarski0Rafał Buczyński1Department of Fuels Technology, Faculty of Energy and Fuels, AGH University of Kraków, al. Adama Mickiewicza 30, 30-059 Cracow, PolandDepartment of Fuels Technology, Faculty of Energy and Fuels, AGH University of Kraków, al. Adama Mickiewicza 30, 30-059 Cracow, PolandThe issue of maintaining low-gradient combustion in the conditions of high heat extraction has been investigated numerically in this work. The analyses include the application of a convective boundary condition at the wall (with estimated boiling heat transfer coefficient); analysis of the Internal Recirculation Device’s impact on combustion products and heat transfer under low-gradient conditions; and comparison of both traditional and low-gradient combustion modes. It was shown that the Internal Recirculation Device material and geometry has a significant impact on the nitrogen oxide (NO<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>x</mi></msub></semantics></math></inline-formula>) formation mechanism, as NO<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula> emission becomes predominant and can rise up to several hundreds ppm. What is more, along with decrease in thermal resistance of the IRD, CO emissions also increase rapidly, even achieving over 2000 ppm. Additionally, the convective heat transfer rate decreased by about 25% after switching from traditional to low-gradient combustion, whereas the radiative mechanism increased by ≈40% compared to traditional mode. It should also be mentioned that the low-gradient combustion applied in this work achieved approximately 10% higher efficiency than conventional combustion.https://www.mdpi.com/1996-1073/17/1/186CFDcombustionlow-gradient combustionheat transferfire-tube boiler |
| spellingShingle | Mieszko Tokarski Rafał Buczyński Heat Transfer Analysis for Combustion under Low-Gradient Conditions in a Small-Scale Industrial Energy Systems Energies CFD combustion low-gradient combustion heat transfer fire-tube boiler |
| title | Heat Transfer Analysis for Combustion under Low-Gradient Conditions in a Small-Scale Industrial Energy Systems |
| title_full | Heat Transfer Analysis for Combustion under Low-Gradient Conditions in a Small-Scale Industrial Energy Systems |
| title_fullStr | Heat Transfer Analysis for Combustion under Low-Gradient Conditions in a Small-Scale Industrial Energy Systems |
| title_full_unstemmed | Heat Transfer Analysis for Combustion under Low-Gradient Conditions in a Small-Scale Industrial Energy Systems |
| title_short | Heat Transfer Analysis for Combustion under Low-Gradient Conditions in a Small-Scale Industrial Energy Systems |
| title_sort | heat transfer analysis for combustion under low gradient conditions in a small scale industrial energy systems |
| topic | CFD combustion low-gradient combustion heat transfer fire-tube boiler |
| url | https://www.mdpi.com/1996-1073/17/1/186 |
| work_keys_str_mv | AT mieszkotokarski heattransferanalysisforcombustionunderlowgradientconditionsinasmallscaleindustrialenergysystems AT rafałbuczynski heattransferanalysisforcombustionunderlowgradientconditionsinasmallscaleindustrialenergysystems |