Experimental Study on Chemiluminescence Properties of Ammonia-Methane Non-Premixed Laminar Flames

The fundamental investigation on the chemiluminescence characteristics of NH<sub>3</sub>-based flames is essential for the development of low-cost, real-time optical diagnostic sensor technologies. In this study, we have experimentally examined the chemiluminescence properties of non-pre...

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Main Authors: Haihang Su, Yuxuan Wu, Jinzhi Yan, Liqiao Jiang
Format: Article
Language:English
Published: MDPI AG 2025-01-01
Series:Energies
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Online Access:https://www.mdpi.com/1996-1073/18/2/402
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author Haihang Su
Yuxuan Wu
Jinzhi Yan
Liqiao Jiang
author_facet Haihang Su
Yuxuan Wu
Jinzhi Yan
Liqiao Jiang
author_sort Haihang Su
collection DOAJ
description The fundamental investigation on the chemiluminescence characteristics of NH<sub>3</sub>-based flames is essential for the development of low-cost, real-time optical diagnostic sensor technologies. In this study, we have experimentally examined the chemiluminescence properties of non-premixed ammonia-methane laminar jet flames under various initial NH<sub>3</sub> blending ratios (<i>X<sub>NH</sub></i><sub>3</sub> from 0.2 to 1.0 in volume) by conducting the emission spectrum analysis within the 200–800 nm band and capturing the distribution images of key excited radicals. The results revealed that the emission spectra of OH*, CH*, CN*, NH*, and NH<sub>2</sub>* were clearly identifiable. As anticipated, the chemiluminescence characteristics of NH<sub>3</sub>-CH<sub>4</sub> non-premixed flames were significantly influenced by <i>X<sub>NH</sub></i><sub>3</sub>; i.e., the overall signal intensity decreased monotonically within the 200–400 nm band but increased within the 400–800 nm band as <i>X<sub>NH</sub></i><sub>3</sub> increased. The signal intensity characteristics of OH*, CH*, NH*, and NH<sub>2</sub>*, indicated by radical images, were consistent with the spectrometer measurements. Particularly, it was found that the intensity ratio of CH*/NH<sub>2</sub>* was an ideal marker of initial <i>X<sub>NH</sub></i><sub>3</sub> in present flames, given their sensitivity with <i>X<sub>NH</sub></i><sub>3</sub> and relative ease of measurement with the cost-effective sensors designed for invisible wavelengths. Moreover, in the flame front, CH* was located in the oxidant side, while NH<sub>2</sub>* was in the fuel side with a broader distribution zone. An increase of <i>X<sub>NH</sub></i><sub>3</sub> led to greater flame thickness and shifted the peak position of excited radicals far away from the fuel side.
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spelling doaj-art-8cf4ff3630aa472e93af2b0828908c1e2025-01-24T13:31:22ZengMDPI AGEnergies1996-10732025-01-0118240210.3390/en18020402Experimental Study on Chemiluminescence Properties of Ammonia-Methane Non-Premixed Laminar FlamesHaihang Su0Yuxuan Wu1Jinzhi Yan2Liqiao Jiang3College of Energy and Power Engineering, Shenyang University of Chemical Technology, Shenyang 110142, ChinaGuangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, ChinaCollege of Energy and Power Engineering, Shenyang University of Chemical Technology, Shenyang 110142, ChinaCollege of Energy and Power Engineering, Shenyang University of Chemical Technology, Shenyang 110142, ChinaThe fundamental investigation on the chemiluminescence characteristics of NH<sub>3</sub>-based flames is essential for the development of low-cost, real-time optical diagnostic sensor technologies. In this study, we have experimentally examined the chemiluminescence properties of non-premixed ammonia-methane laminar jet flames under various initial NH<sub>3</sub> blending ratios (<i>X<sub>NH</sub></i><sub>3</sub> from 0.2 to 1.0 in volume) by conducting the emission spectrum analysis within the 200–800 nm band and capturing the distribution images of key excited radicals. The results revealed that the emission spectra of OH*, CH*, CN*, NH*, and NH<sub>2</sub>* were clearly identifiable. As anticipated, the chemiluminescence characteristics of NH<sub>3</sub>-CH<sub>4</sub> non-premixed flames were significantly influenced by <i>X<sub>NH</sub></i><sub>3</sub>; i.e., the overall signal intensity decreased monotonically within the 200–400 nm band but increased within the 400–800 nm band as <i>X<sub>NH</sub></i><sub>3</sub> increased. The signal intensity characteristics of OH*, CH*, NH*, and NH<sub>2</sub>*, indicated by radical images, were consistent with the spectrometer measurements. Particularly, it was found that the intensity ratio of CH*/NH<sub>2</sub>* was an ideal marker of initial <i>X<sub>NH</sub></i><sub>3</sub> in present flames, given their sensitivity with <i>X<sub>NH</sub></i><sub>3</sub> and relative ease of measurement with the cost-effective sensors designed for invisible wavelengths. Moreover, in the flame front, CH* was located in the oxidant side, while NH<sub>2</sub>* was in the fuel side with a broader distribution zone. An increase of <i>X<sub>NH</sub></i><sub>3</sub> led to greater flame thickness and shifted the peak position of excited radicals far away from the fuel side.https://www.mdpi.com/1996-1073/18/2/402chemiluminescenceexcited radicalsammonia-methane rationon-premixed flame
spellingShingle Haihang Su
Yuxuan Wu
Jinzhi Yan
Liqiao Jiang
Experimental Study on Chemiluminescence Properties of Ammonia-Methane Non-Premixed Laminar Flames
Energies
chemiluminescence
excited radicals
ammonia-methane ratio
non-premixed flame
title Experimental Study on Chemiluminescence Properties of Ammonia-Methane Non-Premixed Laminar Flames
title_full Experimental Study on Chemiluminescence Properties of Ammonia-Methane Non-Premixed Laminar Flames
title_fullStr Experimental Study on Chemiluminescence Properties of Ammonia-Methane Non-Premixed Laminar Flames
title_full_unstemmed Experimental Study on Chemiluminescence Properties of Ammonia-Methane Non-Premixed Laminar Flames
title_short Experimental Study on Chemiluminescence Properties of Ammonia-Methane Non-Premixed Laminar Flames
title_sort experimental study on chemiluminescence properties of ammonia methane non premixed laminar flames
topic chemiluminescence
excited radicals
ammonia-methane ratio
non-premixed flame
url https://www.mdpi.com/1996-1073/18/2/402
work_keys_str_mv AT haihangsu experimentalstudyonchemiluminescencepropertiesofammoniamethanenonpremixedlaminarflames
AT yuxuanwu experimentalstudyonchemiluminescencepropertiesofammoniamethanenonpremixedlaminarflames
AT jinzhiyan experimentalstudyonchemiluminescencepropertiesofammoniamethanenonpremixedlaminarflames
AT liqiaojiang experimentalstudyonchemiluminescencepropertiesofammoniamethanenonpremixedlaminarflames