Masterarbeit (laufend)

Abrham Tadesse Gebrekristos

Numerical Modeling of Wood Pellet Combustion on Commercial and Lab Scale Using DEM/CFD Simulation

The combustion of woody biomass, particularly wood pellets, plays a pivotal role in the decentralized application of renewable energy, especially in the heat market. Understanding and optimizing combustion processes are critical for improving the efficiency and sustainability of pellet combustion systems. Experimental studies, while insightful, often face limitations in capturing the intricate thermochemical processes involved in combustion.
This research leverages a combined numerical approach integrating the Discrete Element Method (DEM) and Computational Fluid Dynamics (CFD) to overcome these limitations. By employing this approach, the work aims to provide a detailed understanding of wood pellet combustion under lab-scale and commercial conditions. The need for such research stems from the increasing global demand for renewable energy sources and the necessity of optimizing combustion systems to reduce emissions and improve energy efficiency.
The primary objective of this master’s Thesis is to model wood pellet combustion using the DEM/CFD approach developed by the Institute for Energy Systems and Energy Process Engineering (LEAT). Key tasks include:

1. Fitting of the chemical reaction based on experimental data from single-particle combustion
2. Modelling the combustion of wood pellets in the lab-scaled reactor using the DEM/CFD approach including comparison to experimental data
3. Meshing of the combustion chamber of three commercially used pellet boilers
4. DEM/CFD-Simulation of the selected cases for the commercial pellet boilers

The outcomes are expected to enhance current knowledge of combustion dynamics and contribute to the development of efficient, scalable renewable energy solutions.