Numerical study on inter-particle effects for multiple reacting biomass and coal particles based on Micro-CT...

Area of Science:

• Combustion science
• Computational fluid dynamics (CFD)
• Renewable energy engineering

Background:

• Co-firing biomass with coal offers environmental benefits and high energy density.
• Conventional numerical simulations often use simplified, ideal particle shapes (e.g., spheres).
• Real biomass and coal particles exhibit complex, non-smoothed, and irregular morphologies.

Purpose of the Study:

• To investigate the impact of realistic particle morphology on interparticle effects during biomass-coal co-firing.
• To analyze fluid dynamics, including temperature distribution, flow patterns, and drag coefficients.
• To inform the development of more accurate computational models for co-firing systems.

Main Methods:

• Particle-scale computational fluid dynamics (CFD) simulations were employed.
• Micro-computed tomography (micro-CT) imaging was used to capture realistic particle shapes.
• Simulations focused on analyzing species transportation, flow fields, and thermal profiles.

Main Results:

• Realistic particle shapes lead to nonuniform flow fields and temperature distributions.
• Irregular particle structures create varied reaction zones and affect overall combustion dynamics.
• Particle orientation significantly influences neighboring particle combustion, an effect missed by spherical models.

Conclusions:

• Realistic particle morphology critically impacts drag and heat transfer in co-firing systems.
• Traditional spherical models are insufficient for accurately capturing these complex interparticle effects.
• A paradigm shift towards realistic particle representation in CFD modeling is essential for improving co-firing efficiency predictions.