Work

Numerical Analysis of Combustion and Thermal Performance of a Bluff-Body and Swirl-Stabilized Micro-Combustor with Premixed NH3/H2/Air Flames

Year: 2025

Type: article

Abstract: A bluff-body and swirl stabilized micro combustor fueled by ammonia/hydrogen mixture has been proposed as a novel flame stabilization technique for zero-carbon micro combustion-based power generators. This study numerically explores how variations in bluff-body geometry, inlet mass flow rate, vane angle, and material influence the combustion and thermal efficiencies of the micro combustor. Key findings indicate that bluff body geometry significantly influences combustion and thermal performances, and cone-shaped bluff-body results in the lowest radiation efficiency among other studied geometries. Furthermore, variations in the inlet mass flow rate were shown to directly impact mean outer wall temperature and emissions, with a marginal effect on combustion efficiency, which remained relatively stable across different flow rates. An inlet mass flow rate of was identified as optimal for achieving the highest combustion efficiency of and the most uniform mean outer wall temperature. Additionally, the study also unveiled that modifying the vane angle of the swirler from 15 degrees to 60 degrees significantly enhances mean outer wall temperature, outer wall temperature uniformity, combustion and radiation efficiencies, along with emissions, and a 60-degree swirler was particularly effective, achieving around radiation efficiency. Lastly, the choice of combustor material was found to be pivotal, with silicon carbide material outperforming others by delivering the highest mean outer wall temperature (approximately 910 K), radiation efficiency (around 38.5%), and the most uniform outer wall temperature. In contrast, stainless steel displayed the lowest thermal performance metrics. This research offers valuable insights and guidance for the development and optimization of micro combustion-based power generators, aiming to minimize carbon emissions and improve energy efficiency.

Source: Energies

DOI: 10.3390/en18040780

Authors: Soroush Sheykhbaglou, Pavlos Dimitriou

Institutions: Guangdong Technion-Israel Institute of Technology, Technion – Israel Institute of Technology

Language: English

Topic: Combustion and flame dynamics

Subfield: Computational Mechanics

Field: Engineering

Domain: Physical Sciences

SDGs: Affordable and clean energy, Climate action

Open Access status: gold

Estimated APC paid: $3,137