Title:
Moving Grate Combustion Optimisation with CFD and PIV
Author(s):
Nussbaumer, T., Kiener, M
Document(s):
Paper
Abstract:
Grate boilers are often applied for biofuels with high ash and moisture content. In heating applications, part load operation often occurs. The paper presents measures to optimise the fluid dynamics in moving grate boilers to improve the part load capability. For this purpose, the secondary air injection and obstacles in the combustion chamber are investigated by Computational Fluid Dynamics (CFD) and validated by model experiments with Particle Image Velocimetry (PIV). The most promising concepts are implemented in a 1.2 MW boiler and experimentally validated. The results show that the combustion quality can be improved by a factor of 4 compared to a reference case with already low emissions. In addition, the boiler can be operated at lower excess air ratio, which enables an efficiency increase. By implementation of the presented measures, a stable operation from little below 30% load to full load can be achieved with CO emissions below 15 mg/mn3 at 11 Vol.-% O2 at an excess air ratio of 1.8. However, beside optimum fluid dynamics, undisturbed grate coverage is advantageous to achieve good combustion quality.
Keywords:
emissions, modelling, grate combustion, modeling, part load
Topic:
R&D on Biomass Conversion Technologies for Heating, Electricity and Chemicals
Subtopic:
Solid biofuel combustion for small and medium scale applications
Event:
21st European Biomass Conference and Exhibition
Session:
2DV.3.15
Pages:
1112 - 1117
ISBN:
978-88-89407-53-0
Paper DOI:
10.5071/21stEUBCE2013-2DV.3.15
Price:
FREE
