Effect of the distance between fuel and oxidizer nozzles on NOx emissions from spray combustion furnaces incorporating high-temperature preheated oxidizers
The objective of the present study was to investigate the effect of the distance between fuel and oxidizer nozzles on NOx emissions from a laboratory-scale spray combustion furnace simulating an industrial high-temperature air combustion (HiTAC) furnace. The furnace employed in these trials was fuel...
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| Format: | Article |
| Language: | English |
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The Japan Society of Mechanical Engineers
2015-03-01
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| Series: | Journal of Thermal Science and Technology |
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| Online Access: | https://www.jstage.jst.go.jp/article/jtst/10/1/10_2015jtst0007/_pdf/-char/en |
| _version_ | 1818313018503593984 |
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| author | Yuzuru NADA Shintaro SHIBATA Masahiko IMAOKA Yoshiyuki KIDOGUCHI |
| author_facet | Yuzuru NADA Shintaro SHIBATA Masahiko IMAOKA Yoshiyuki KIDOGUCHI |
| author_sort | Yuzuru NADA |
| collection | DOAJ |
| description | The objective of the present study was to investigate the effect of the distance between fuel and oxidizer nozzles on NOx emissions from a laboratory-scale spray combustion furnace simulating an industrial high-temperature air combustion (HiTAC) furnace. The furnace employed in these trials was fueled with commercially obtainable kerosene in combination with highly preheated oxidizer gases. The oxidizer was pre-diluted by the addition of nitrogen in order to produce dilution levels equivalent to those in industrial HiTAC furnaces. The resulting NOx measurements indicate a trend opposite to that reported by previous studies, such that increasing the distance between the nozzles increases the NOx emissions, and a theory is advanced to explain this unusual observation. In a furnace within which the nozzle distance in the burner is small, the properties of the oxidizer supplied from the nozzle located near the spray nozzle greatly affect NOx emissions. The use of an oxidizer with a much lower preheat temperature and a lower O2 concentration induces flame lifting further downstream, which significantly reduces NOx emissions through the formation of an invisible flame exhibiting a uniform temperature distribution throughout the furnace. In contrast, in a furnace in which the burner has a large nozzle distance, a highly luminous flame is anchored near the spray nozzle exit due to ignition of fuel vapor by high-temperature burned gases recirculated to the lower section of the furnace. This flame represents a zone with high combustion intensity and generates significant NOx emissions. In such cases, the influence of the oxidizer properties is moderated due to the widely separated nozzle locations. |
| first_indexed | 2024-12-13T08:27:04Z |
| format | Article |
| id | doaj.art-a535a303ef8c40acb1482d4284838197 |
| institution | Directory Open Access Journal |
| issn | 1880-5566 |
| language | English |
| last_indexed | 2024-12-13T08:27:04Z |
| publishDate | 2015-03-01 |
| publisher | The Japan Society of Mechanical Engineers |
| record_format | Article |
| series | Journal of Thermal Science and Technology |
| spelling | doaj.art-a535a303ef8c40acb1482d42848381972022-12-21T23:53:52ZengThe Japan Society of Mechanical EngineersJournal of Thermal Science and Technology1880-55662015-03-01101JTST0007JTST000710.1299/jtst.2015jtst0007jtstEffect of the distance between fuel and oxidizer nozzles on NOx emissions from spray combustion furnaces incorporating high-temperature preheated oxidizersYuzuru NADA0Shintaro SHIBATA1Masahiko IMAOKA2Yoshiyuki KIDOGUCHI3Department of Energy System, The University of TokushimaDepartment of Energy System, The University of TokushimaDepartment of Energy System, The University of TokushimaDepartment of Energy System, The University of TokushimaThe objective of the present study was to investigate the effect of the distance between fuel and oxidizer nozzles on NOx emissions from a laboratory-scale spray combustion furnace simulating an industrial high-temperature air combustion (HiTAC) furnace. The furnace employed in these trials was fueled with commercially obtainable kerosene in combination with highly preheated oxidizer gases. The oxidizer was pre-diluted by the addition of nitrogen in order to produce dilution levels equivalent to those in industrial HiTAC furnaces. The resulting NOx measurements indicate a trend opposite to that reported by previous studies, such that increasing the distance between the nozzles increases the NOx emissions, and a theory is advanced to explain this unusual observation. In a furnace within which the nozzle distance in the burner is small, the properties of the oxidizer supplied from the nozzle located near the spray nozzle greatly affect NOx emissions. The use of an oxidizer with a much lower preheat temperature and a lower O2 concentration induces flame lifting further downstream, which significantly reduces NOx emissions through the formation of an invisible flame exhibiting a uniform temperature distribution throughout the furnace. In contrast, in a furnace in which the burner has a large nozzle distance, a highly luminous flame is anchored near the spray nozzle exit due to ignition of fuel vapor by high-temperature burned gases recirculated to the lower section of the furnace. This flame represents a zone with high combustion intensity and generates significant NOx emissions. In such cases, the influence of the oxidizer properties is moderated due to the widely separated nozzle locations.https://www.jstage.jst.go.jp/article/jtst/10/1/10_2015jtst0007/_pdf/-char/enhigh temperature air combustionspray combustionnox emissionnozzle distanceburned gas recirculation |
| spellingShingle | Yuzuru NADA Shintaro SHIBATA Masahiko IMAOKA Yoshiyuki KIDOGUCHI Effect of the distance between fuel and oxidizer nozzles on NOx emissions from spray combustion furnaces incorporating high-temperature preheated oxidizers Journal of Thermal Science and Technology high temperature air combustion spray combustion nox emission nozzle distance burned gas recirculation |
| title | Effect of the distance between fuel and oxidizer nozzles on NOx emissions from spray combustion furnaces incorporating high-temperature preheated oxidizers |
| title_full | Effect of the distance between fuel and oxidizer nozzles on NOx emissions from spray combustion furnaces incorporating high-temperature preheated oxidizers |
| title_fullStr | Effect of the distance between fuel and oxidizer nozzles on NOx emissions from spray combustion furnaces incorporating high-temperature preheated oxidizers |
| title_full_unstemmed | Effect of the distance between fuel and oxidizer nozzles on NOx emissions from spray combustion furnaces incorporating high-temperature preheated oxidizers |
| title_short | Effect of the distance between fuel and oxidizer nozzles on NOx emissions from spray combustion furnaces incorporating high-temperature preheated oxidizers |
| title_sort | effect of the distance between fuel and oxidizer nozzles on nox emissions from spray combustion furnaces incorporating high temperature preheated oxidizers |
| topic | high temperature air combustion spray combustion nox emission nozzle distance burned gas recirculation |
| url | https://www.jstage.jst.go.jp/article/jtst/10/1/10_2015jtst0007/_pdf/-char/en |
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