Numerical Study of the Influence of Secondary Air Uniformity on Jet Penetration and Gas-Solid Diffusion Characteristics in a Large-Scale CFB Boiler
The uniformity of secondary air (SA) in large-scale CFB boilers has an important influence on gas-solid flow and combustion, but was seldom considered in previous studies. Numerical simulation based on the Eulerian–Eulerian and RNG k-ε turbulence models was conducted to explore the influence of SA u...
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MDPI AG
2021-09-01
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| Online Access: | https://www.mdpi.com/1996-1073/14/18/5679 |
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| author | Xiong Zheng Jin Yan Jinping Wang Xiaofeng Lu |
| author_facet | Xiong Zheng Jin Yan Jinping Wang Xiaofeng Lu |
| author_sort | Xiong Zheng |
| collection | DOAJ |
| description | The uniformity of secondary air (SA) in large-scale CFB boilers has an important influence on gas-solid flow and combustion, but was seldom considered in previous studies. Numerical simulation based on the Eulerian–Eulerian and RNG k-ε turbulence models was conducted to explore the influence of SA uniformity and load variation on jet penetration, diffusion characteristics and gas-solid mixing in the first 600 MW supercritical CFB boiler. The results showed that better SA uniformity was conductive to the uniformity of SA penetration and gas-solid mixing along the furnace height, although the penetration depth and diffusion distance showed an opposite trend. In addition, the penetration depth and diffusion distance got enhanced with higher boiler load. The inner and outer SA jets could not cover the furnace width, and the uneven SA uniformity led to a huge deviation of the solid concentration within 10 m of the air distributor. Eventually, a calculation model was successfully established for predicting the penetration depth of inclined thermal SA jets during boiler operation. |
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| id | doaj.art-4237d349dac544aa80bd3be0b5b3070c |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-10T07:43:21Z |
| publishDate | 2021-09-01 |
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| series | Energies |
| spelling | doaj.art-4237d349dac544aa80bd3be0b5b3070c2023-11-22T12:51:17ZengMDPI AGEnergies1996-10732021-09-011418567910.3390/en14185679Numerical Study of the Influence of Secondary Air Uniformity on Jet Penetration and Gas-Solid Diffusion Characteristics in a Large-Scale CFB BoilerXiong Zheng0Jin Yan1Jinping Wang2Xiaofeng Lu3Key Laboratory of Low-Grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education of PRC, Chongqing 400044, ChinaKey Laboratory of Low-Grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education of PRC, Chongqing 400044, ChinaNanjing Institute of Technology, College of Energy and Power Engineering, Nanjing 211167, ChinaKey Laboratory of Low-Grade Energy Utilization Technologies and Systems, Chongqing University, Ministry of Education of PRC, Chongqing 400044, ChinaThe uniformity of secondary air (SA) in large-scale CFB boilers has an important influence on gas-solid flow and combustion, but was seldom considered in previous studies. Numerical simulation based on the Eulerian–Eulerian and RNG k-ε turbulence models was conducted to explore the influence of SA uniformity and load variation on jet penetration, diffusion characteristics and gas-solid mixing in the first 600 MW supercritical CFB boiler. The results showed that better SA uniformity was conductive to the uniformity of SA penetration and gas-solid mixing along the furnace height, although the penetration depth and diffusion distance showed an opposite trend. In addition, the penetration depth and diffusion distance got enhanced with higher boiler load. The inner and outer SA jets could not cover the furnace width, and the uneven SA uniformity led to a huge deviation of the solid concentration within 10 m of the air distributor. Eventually, a calculation model was successfully established for predicting the penetration depth of inclined thermal SA jets during boiler operation.https://www.mdpi.com/1996-1073/14/18/5679CFB boilersecondary air uniformitygas-solid flowjet penetrationlateral diffusion |
| spellingShingle | Xiong Zheng Jin Yan Jinping Wang Xiaofeng Lu Numerical Study of the Influence of Secondary Air Uniformity on Jet Penetration and Gas-Solid Diffusion Characteristics in a Large-Scale CFB Boiler Energies CFB boiler secondary air uniformity gas-solid flow jet penetration lateral diffusion |
| title | Numerical Study of the Influence of Secondary Air Uniformity on Jet Penetration and Gas-Solid Diffusion Characteristics in a Large-Scale CFB Boiler |
| title_full | Numerical Study of the Influence of Secondary Air Uniformity on Jet Penetration and Gas-Solid Diffusion Characteristics in a Large-Scale CFB Boiler |
| title_fullStr | Numerical Study of the Influence of Secondary Air Uniformity on Jet Penetration and Gas-Solid Diffusion Characteristics in a Large-Scale CFB Boiler |
| title_full_unstemmed | Numerical Study of the Influence of Secondary Air Uniformity on Jet Penetration and Gas-Solid Diffusion Characteristics in a Large-Scale CFB Boiler |
| title_short | Numerical Study of the Influence of Secondary Air Uniformity on Jet Penetration and Gas-Solid Diffusion Characteristics in a Large-Scale CFB Boiler |
| title_sort | numerical study of the influence of secondary air uniformity on jet penetration and gas solid diffusion characteristics in a large scale cfb boiler |
| topic | CFB boiler secondary air uniformity gas-solid flow jet penetration lateral diffusion |
| url | https://www.mdpi.com/1996-1073/14/18/5679 |
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