Application of the NOx Reaction Model for Development of Low-NOx Combustion Technology for Pulverized Coals by Using the Gas Phase Stoichiometric Ratio Index
We previously proposed the gas phase stoichiometric ratio (SRgas) as an index to evaluate NOx concentration in fuel-rich flames. The SRgas index was defined as the amount of fuel required for stoichiometric combustion/amount of gasified fuel, where the amount of gasified fuel was the amount of fuel...
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doaj-90e73cc2993946adb2ae29a7d04172332020-11-25T00:37:43ZengMDPI AGEnergies1996-10732011-03-014354556210.3390/en4030545Application of the NOx Reaction Model for Development of Low-NOx Combustion Technology for Pulverized Coals by Using the Gas Phase Stoichiometric Ratio IndexKenji YamamotoHironobu KobayashiTsuyoshi ShibataYuki KamikawaMasayuki TaniguchiWe previously proposed the gas phase stoichiometric ratio (SRgas) as an index to evaluate NOx concentration in fuel-rich flames. The SRgas index was defined as the amount of fuel required for stoichiometric combustion/amount of gasified fuel, where the amount of gasified fuel was the amount of fuel which had been released to the gas phase by pyrolysis, oxidation and gasification reactions. In the present study we found that SRgas was a good index to consider the gas phase reaction mechanism in fuel-rich pulverized coal flames. When SRgas < 1.0, NOx concentration was strongly influenced by the SRgas value. NOx concentration was also calculated by using a reaction model. The model was verified for various coals, particle diameters, reaction times, and initial oxygen concentrations. The most important reactions were gas phase NOx reduction reactions by hydrocarbons. The hydrocarbon concentration was estimated based on SRgas. We also investigated the ratio as an index to develop a new low-NOx combustion technology for pulverized coals. We examined the relation between local SRgas distribution in the fuel-rich region in the low-NOx flame and NOx emissions at the furnace exit, by varying burner structures. The relationship between local SRgas value and local NOx concentration was also examined. When a low-NOx type burner was used, the value of SRgas in the flame was readily decreased. When the local SRgas value was the same, it was difficult to influence the local NOx concentration by changing the burner structure. For staged combustion, the most important item was to design the burner structure and arrangement so that SRgas could be lowered as much as possible just before mixing with staged air. http://www.mdpi.com/1996-1073/4/3/545/low-NOx combustionpulverized coalsNOx reductiongas phase stoichiometric ratiohydrocarbons |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Kenji Yamamoto Hironobu Kobayashi Tsuyoshi Shibata Yuki Kamikawa Masayuki Taniguchi |
spellingShingle |
Kenji Yamamoto Hironobu Kobayashi Tsuyoshi Shibata Yuki Kamikawa Masayuki Taniguchi Application of the NOx Reaction Model for Development of Low-NOx Combustion Technology for Pulverized Coals by Using the Gas Phase Stoichiometric Ratio Index Energies low-NOx combustion pulverized coals NOx reduction gas phase stoichiometric ratio hydrocarbons |
author_facet |
Kenji Yamamoto Hironobu Kobayashi Tsuyoshi Shibata Yuki Kamikawa Masayuki Taniguchi |
author_sort |
Kenji Yamamoto |
title |
Application of the NOx Reaction Model for Development of Low-NOx Combustion Technology for Pulverized Coals by Using the Gas Phase Stoichiometric Ratio Index |
title_short |
Application of the NOx Reaction Model for Development of Low-NOx Combustion Technology for Pulverized Coals by Using the Gas Phase Stoichiometric Ratio Index |
title_full |
Application of the NOx Reaction Model for Development of Low-NOx Combustion Technology for Pulverized Coals by Using the Gas Phase Stoichiometric Ratio Index |
title_fullStr |
Application of the NOx Reaction Model for Development of Low-NOx Combustion Technology for Pulverized Coals by Using the Gas Phase Stoichiometric Ratio Index |
title_full_unstemmed |
Application of the NOx Reaction Model for Development of Low-NOx Combustion Technology for Pulverized Coals by Using the Gas Phase Stoichiometric Ratio Index |
title_sort |
application of the nox reaction model for development of low-nox combustion technology for pulverized coals by using the gas phase stoichiometric ratio index |
publisher |
MDPI AG |
series |
Energies |
issn |
1996-1073 |
publishDate |
2011-03-01 |
description |
We previously proposed the gas phase stoichiometric ratio (SRgas) as an index to evaluate NOx concentration in fuel-rich flames. The SRgas index was defined as the amount of fuel required for stoichiometric combustion/amount of gasified fuel, where the amount of gasified fuel was the amount of fuel which had been released to the gas phase by pyrolysis, oxidation and gasification reactions. In the present study we found that SRgas was a good index to consider the gas phase reaction mechanism in fuel-rich pulverized coal flames. When SRgas < 1.0, NOx concentration was strongly influenced by the SRgas value. NOx concentration was also calculated by using a reaction model. The model was verified for various coals, particle diameters, reaction times, and initial oxygen concentrations. The most important reactions were gas phase NOx reduction reactions by hydrocarbons. The hydrocarbon concentration was estimated based on SRgas. We also investigated the ratio as an index to develop a new low-NOx combustion technology for pulverized coals. We examined the relation between local SRgas distribution in the fuel-rich region in the low-NOx flame and NOx emissions at the furnace exit, by varying burner structures. The relationship between local SRgas value and local NOx concentration was also examined. When a low-NOx type burner was used, the value of SRgas in the flame was readily decreased. When the local SRgas value was the same, it was difficult to influence the local NOx concentration by changing the burner structure. For staged combustion, the most important item was to design the burner structure and arrangement so that SRgas could be lowered as much as possible just before mixing with staged air. |
topic |
low-NOx combustion pulverized coals NOx reduction gas phase stoichiometric ratio hydrocarbons |
url |
http://www.mdpi.com/1996-1073/4/3/545/ |
work_keys_str_mv |
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