Abstract: This paper is aimed to study combustion characteristics
of low NOx burner using petroleum cokes as fuel. The petroleum coke,
which is produced through the oil refining process, is an attractive fuel
in terms of its high heating value and low price. But petroleum coke is
a challenging fuel because of its low volatile content, high sulfur and
nitrogen content, which give rise to undesirable emission
characteristics and low ignitability. Therefore, the research and
development regarding the petroleum coke burner is needed for
applying this industrial system. In this study, combustion and emission
characteristics of petroleum cokes burner are experimentally
investigated in an industrial steam boiler. The low NOx burner is
designed to control fuel and air mixing to achieve staged combustion,
which, in turn reduces both flame temperature and oxygen. Air
distribution ratio of triple staged air is optimized experimentally. The
result showed that NOx concentration is lowest when overfire air is
used, and the burner function at a fuel rich condition. That is, the
burner is operated at the equivalence ratio of 1.67 and overall
equivalence ratio including overfire air is kept 0.87.
Abstract: This study is aiming at establishing the relationship
between the optical signal of flame and an equivalent ratio of flame. In
this experiment, flame optical signal in a furnace is measured using
photodiode. The combustion system is composed of metal fiber burner
and vertical furnace, and flame chemiluminescence is measured at
various experimental conditions. In this study, the flame
chemiluminescence of laminar premixed flame is measured using
commercially available photodiode. It is experimentally investigated
the relationship between equivalent ratio and photodiode signal. In
addition, the strategy of combustion control method is proposed using
the optical signal and fuel pressure.
The results showed that certain relationship between optical data of
photodiode and equivalence ratio exists, and this leads to the
successful application of this system for instantaneous measurement of
equivalence ration of the combustion system.
Abstract: A noble low NOx combustion technology, based on
partial oxidation combustion concept in a fuel rich combustion zone, is
successfully applied in this research. The burner is designed such that
a portion of fuel is heated and pre-vaporized in the furnace then
injected into a fuel rich combustion zone so that a partial oxidation
reaction occurs. The effects of equivalence ratio, thermal load, and
fuel distribution ratio on the emissions of NOx and CO are
experimentally investigated. This newly developed combustion
technology showed very low NOx emission level, about 12 ppm, when
light oil is used as a fuel.