2022 Fiscal Year Annual Research Report
Experimental and numerical study on the interactions between liquid ammonia flashing spray and flame properties for carbon-free technologies.
| Project/Area Number |
21K14085
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| Research Institution | Tohoku University |
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Principal Investigator |
COLSON SOPHIE 東北大学, 流体科学研究所, 特任助教 (60898386)
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| Project Period (FY) |
2021-04-01 – 2023-03-31
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| Keywords | liquid ammonia / spray combustion / flash-boiling spray / spray modeling / spray characteristics / model validation |
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| Outline of Annual Research Achievements |
After the burner realization and the preliminary study conducted on a range of commercial pressure swirl atomizer nozzles during the first year of the project, simple injection nozzles were designed and manufactured for studying the effect of flash-boiling for ammonia spray on a more fundamental approach during this second year of the project. The effect of the aspect ratio and diameter of the orifice of the nozzle on the transition to flash-boiling was studied. In addition, the impact of the injection temperature was also considered. The liquid ammonia jet was observed using backlit imaging. Both temperature and orifice aspect ratio affected the transition to flashing of the liquid ammonia jet, whereas the orifice diameter had a lower impact. Existing transition criteria could not capture the effect of the change in the aspect ratio observed in this study and further discussion on the impact of in-nozzle geometry on flash-boiling is needed. The data obtained in this study also constitute a valuable database for numerical modeling validation, with actual flow rate value and spray angles determined for the various geometry considered. To study the effect of the in-nozzle geometry, glass nozzles were also realized, and two-phase flow could be observed in the nozzle, and associated with a broader spray angle and finer atomization. Combustion experiments in an oxygen-enriched coflow were also realized with a focus on the change in the range of stabilization of the flame when both injection temperature and orifice geometry were changed.
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| Remarks |
Journal paper currently under review (Fuel)
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