ACARP Project Number: C18045
Published: October 11
Anthony Williams, Johan Kosasi, Philip
Bennett, Don Holcombe
Extended
Abstract
The Australian export thermal seaborne coal
market has grown significantly over the last 25 years and apart
from the growth of the market, there have been a number of
significant developments in the industry over the last couple of
decades. Technology utilised by end users of Australian coals has
advanced significantly during this timeframe and producers need
access to a test facility that can simulate these to maintain
competiveness. The ALS-ACIRL pilot scale combustion test facility
is one of the few independent facilities available in the world for
testing thermal coals. Since its construction and commissioning in
1985, is has been used extensively to evaluate coal quality,
investigate beneficiation and blending options, and conduct
numerous research programmes aimed at improving the understanding
of aspects of thermal coal combustion. The primary objective of the
research project was to upgrade ALS-ACIRL's pilot scale combustion
facility to simulate modern power plant technology. The upgrade
proposed a modification of the burner from the conventional burner
to a low-NOx burner.
CFD modelling was performed by the University of
Newcastle to assess potential design modifications and recommend a
design. The design was validated with a series of combustion tests
to investigate NOx reduction potential and impact on burnout
efficiency. The validation tests confirmed NOx reductions in the
order of 30 percent could be made with only a small impact on
burnout efficiency.
Modifications were made to the combustion furnace
to allow tertiary air flow through eight nozzles located around the
burner. Two nozzles diameters were investigated. Several validation
tests with two test coals showed NOx emissions could be reduced by
approximately 30 percent but with a detrimental effect on burnout
efficiency. Utilising the larger diameter nozzle which produced a
lower tertiary air velocity, the deterioration in burnout
efficiency was acceptable.
ALS-ACIRL's combustion test facility was
successfully upgraded to simulate a first generation low-NOx
combustion burner which is capable of reducing NOx emissions by up
to 30 percent. The upgraded facility is capable of differentiating
coal quality performance between different coals.
