Simulation of Combustion Air Flow in the Gasification Biomass Boiler

Marek Patsch,Peter Pilát,M Malcho,J Jandačka,P Ďurčanský,P Pilát,R Lenhard,R Nosek,P Nemec,L Orman,M Holubčík,M Patsch,K Kaduchová,A Čaja

doi:10.1051/matecconf/201816802015

Abstract

The article deals with the optimization of biomass combustion in a small heat source by means of an optimal distribution of combustion air. The uneven distribution of combustion air has been observed in certification tests and in real operation of used heat source and it has an influence on uneven combustion of biomass in the gasification chamber, on increase emissions and combustion losses. At this stage of the research, optimization of the combustion air distribution is performed by CFD simulations, which will be later verified by PIV measuring of the velocity fields in gasification and combustion chambers of the experimental heat source. CFD simulations and subsequent PIV measurements on the experimental device are realized without real combustion, only the air flow in the empty gasification chamber and in the combustion chamber is investigated. This approach has been chosen to simplify calculations and experiments, and on the assumption that when the combustion air distribution is optimal in empty chambers, it will be optimal even during real combustion. The primary air flow in the gasification chamber is in real operation affected by the size and shape of the inserted biomass and its placement in chamber and this effect is accidental and difficult to verifiable.

Highlights

Gasification heat sources are a modern way of biomass energy utilization where combustion is with high efficiency and low emissions [6]
Simulations have shown in particular the uneven distribution of primary air flow in the gasification chamber at higher volumetric air flow through the combustion air fan
The more uneven distribution of primary air is more apparent in vertical cross-sections which are guided closer to the wall of the gasification chamber

Summary

Introduction

Gasification heat sources are a modern way of biomass energy utilization where combustion is with high efficiency and low emissions [6]. In the third zone there is a total burning of gases in the boiler's combustion chamber and the removal of flue gases through the pipe heat exchanger into the chimney.

Results

Conclusion