Combustion characteristics of ammonia–air in a heat-recirculating Swiss-roll burner DOI

Bowen Sun,

Xin Kang, Yu Wang

et al.

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(11)

Published: Nov. 1, 2024

Ammonia has emerged as a promising carbon-free fuel for mitigating greenhouse gas emissions. However, its application in practical combustion systems is limited by several issues including low heating value and slow flame propagation speed, which have posed challenges maintaining stable combustion. As an attempt to resolve these issues, we numerically investigated premixed ammonia–air using detailed chemical mechanism heat-recirculating, Swiss-roll burner that was proposed based on the concept of “excess-enthalpy.” The main focus put stabilizations well characteristics NO/N2O emissions across wide range operational conditions. results showed use led significantly broadened stability regime pure ammonia combustion, could be attributed effective preheating from products unburnt mixture. relationship between dimensionless heat transfer parameter excess-enthalpy quantified linear correlation revealed. In addition, flow expansion recirculation within chamber generation vortices, also beneficial stabilizations. NO at outlet were witnessed growth laminar region, gentler increase flow-transition stage, final leveling off turbulent condition with Reynolds number. For given number, emission non-monotonic variation equivalence ratios, relatively levels either fuel-lean or fuel-rich another major concern, N2O found more significant region conditions, both should avoided operations.

Language: Английский

Investigation on thermophotovoltaic performance enhancement of the hydrogen fueled micro combustors with the center-cleared twisted tapes for micro-thermophotovoltaic system DOI
Jintao Li,

E Jiaqiang,

Jiangjun Ding

et al.

Applied Thermal Engineering, Journal Year: 2025, Volume and Issue: 264, P. 125483 - 125483

Published: Jan. 9, 2025

Language: Английский

Citations

3
Effects of deformed twisted tapes on thermal performance enhancement of hydrogen fueled micro combustor for micro-thermophotovoltaic system DOI
Jintao Li,

E Jiaqiang,

Jiangjun Ding

et al.

Applied Thermal Engineering, Journal Year: 2025, Volume and Issue: 264, P. 125413 - 125413

Published: Jan. 5, 2025

Language: Английский

Citations

2
Optimization of a miniature tubular combustor filled with a T-shaped porous zone for flame stability enhancement DOI
Guangyao Yang, Aiwu Fan

Fuel, Journal Year: 2025, Volume and Issue: 391, P. 134610 - 134610

Published: Feb. 20, 2025

Language: Английский

Citations

0
Dynamics of unsteady premixed flames in meso-scale channels and the effects of varying the wall heating conditions DOI
Akhil Aravind, Gautham Vadlamudi, Saptarshi Basu

et al.

Journal of Fluid Mechanics, Journal Year: 2025, Volume and Issue: 1008

Published: April 2, 2025

Understanding the dynamics of flames at small scales opens up opportunities to enhance performance small-scale power generation devices, micro-reactors, fire safety devices and numerous other systems that confine combustion micro/meso scales. The current study investigates laminar premixed methane–air in meso-scale channels. A cylindrical quartz tube, functioning as an optically accessible combustor, is externally heated by a primary heater facilitate auto-ignition reactant mixture flowing through tube. Experiments were conducted over wide range Reynolds numbers ( $Re$ ) equivalence ratios $\Phi$ ). Apart from previously documented observations unsteady with repetitive extinction ignition (FREI) characteristics, this identifies additional propagating flame (PF) regime. While FREI appeared stoichiometric fuel-rich conditions, PFs observed ratio $0.8$ . Unlike regime, where extinguishes after characteristic travel distance, continue till they reach upstream end combustor extinguish upon encountering meshed constriction. These are associated heat release rate oscillation couples pressure fluctuations frequencies close natural harmonic further how variations wall temperature profile affect PF regimes. To achieve this, secondary introduced varying distances heater, effectively imposing distinct bimodal heating profiles trends justified using simplified theoretical arguments based on estimate mean flow propagation model accounts for losses. novel findings work provide valuable insights can significantly impact design development advanced micro/meso-scale systems.

Language: Английский

Citations

0
Numerical investigation on the combustion characteristics and NOx emission of non-premixed H2/NH3/air in vase-shaped micro combustor DOI
Yi Zhang,

Yang Yang,

Junjie Weng

et al.

International Journal of Hydrogen Energy, Journal Year: 2024, Volume and Issue: 91, P. 539 - 547

Published: Oct. 16, 2024

Language: Английский

Citations

3
Effect of water vapor addition on the combustion characteristics in partially premixed swirling ammonia/methane/air flames DOI
N. Li, Yueru Chen, Jieyu Jiang

et al.

International Journal of Hydrogen Energy, Journal Year: 2025, Volume and Issue: 128, P. 10 - 21

Published: April 15, 2025

Language: Английский

Citations

0
Experimental evaluation and mechanism analysis of combustion performance enhancement in composite wall-assisted methane/air mixtures DOI
Tao Cai,

Lingjie Gao,

Aikun Tang

et al.

Energy, Journal Year: 2024, Volume and Issue: unknown, P. 133944 - 133944

Published: Nov. 1, 2024

Language: Английский

Citations

1
Combustion characteristics of ammonia–air in a heat-recirculating Swiss-roll burner DOI

Bowen Sun,

Xin Kang, Yu Wang

et al.

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(11)

Published: Nov. 1, 2024

Ammonia has emerged as a promising carbon-free fuel for mitigating greenhouse gas emissions. However, its application in practical combustion systems is limited by several issues including low heating value and slow flame propagation speed, which have posed challenges maintaining stable combustion. As an attempt to resolve these issues, we numerically investigated premixed ammonia–air using detailed chemical mechanism heat-recirculating, Swiss-roll burner that was proposed based on the concept of “excess-enthalpy.” The main focus put stabilizations well characteristics NO/N2O emissions across wide range operational conditions. results showed use led significantly broadened stability regime pure ammonia combustion, could be attributed effective preheating from products unburnt mixture. relationship between dimensionless heat transfer parameter excess-enthalpy quantified linear correlation revealed. In addition, flow expansion recirculation within chamber generation vortices, also beneficial stabilizations. NO at outlet were witnessed growth laminar region, gentler increase flow-transition stage, final leveling off turbulent condition with Reynolds number. For given number, emission non-monotonic variation equivalence ratios, relatively levels either fuel-lean or fuel-rich another major concern, N2O found more significant region conditions, both should avoided operations.

Language: Английский

Citations

0