High intensity combustion of coal with water injection

Liu, Da-Hua; Zghoul, A.M.; Li, Zongwen; Tan, Bon-Siau; Lockwood, Karl L.; Essenhigh, Robert H.

doi:10.1016/0010-2180(86)90110-0

Cited by 7 publications

(2 citation statements)

References 4 publications

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“…During combustion of such slurries, reduced NO x formation has been observed mainly as a result of lower flame temperatures. , In this respect, combustion tests in a pilot-scale burner found the NO x level to be less than 500 ppm . The burner configuration is also an important parameter for the oxides formation related to the air excess or secondary and tertiary air inlet in the combustion zone .…”

Section: Introductionmentioning

confidence: 99%

Preparation and Rheological Characterization of Lignite−Water Slurries^†

Goudoulas¹,

Kastrinakis²,

Nychas³

2010

Energy Fuels

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This paper reports the preparation of lignite-water slurries (LWS) and critical characteristics affecting their rheology. The slurries were prepared using wet grinding in a ball mill, having particle size distributions up to 300 μm and concentrations up to 50 wt % in solids. Surfactants and polyelectrolytes were used as additives in the slurryfication process to achieve acceptable rheological behavior and stability. Rheological measurements were performed using parallel disks geometry, and the typical shear rates were on the order from 10 -2 to 10 3 s -1 . The effect of the particle size distribution was investigated, and the apparent viscosity of the slurries, for the same solids volume fraction, was found to be lower for broad multimodal distributions. In addition, oscillatory rheological measurements were carried out to investigate the microstructure of the slurries, and it was observed that, for dense LWS (φ > 0.40), the viscoelastic behavior was controlled by the elastic contribution than the viscous one. When the experimental results of the lignite slurries were compared to rheological models of viscosity, satisfactory agreement was found, although relatively low values of φ max were observed, attributed to the physicochemical properties and the shape of the lignite particles. The results of the present study point out that, with an adequate protocol of measurement and, in turn, reproducible data, the apparent viscosity curves of LWS can be effectively described, qualitatively as well as quantitatively, by a well-established model.

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Section: Introductionmentioning

confidence: 99%

Preparation and Rheological Characterization of Lignite−Water Slurries^†

Goudoulas¹,

Kastrinakis²,

Nychas³

2010

Energy Fuels

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“…In another study, the dilution extinction limits of H 2 −O 2 diffusion flames were assessed by mixing water with the fuel, where H 2 O modeled combustion products [28]. Other reasons for water injection into the combustion chamber include decreasing exhaust temperature and associated NOx emissions, flame extinguishment, or studying combustion efficiency [29][30][31][32].…”

Section: Introductionmentioning

confidence: 99%

Pressure effects on real-gas laminar counterflow

Juanós

Sirignano

2017

Combustion and Flame

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Two important problems are studied: the combustion of hydrocarbons at higher pressures and the burning of hydrocarbon/water-vapor mixtures both of which are relevant to many applications including diesel combustion and hydrate fuels. To study both of these problems, a numerical analysis of a steady laminar methane-air counterflow diffusion flame at high pressure is presented. The mathematical model is based on the well-known similar solution for counterflow with special considerations given to the high density and to detailed transport and chemistry. Modifications of transport properties and associated time scales with increasing pressure are considered. Real gas behavior is examined through the use of a cubic equation of state and an enthalpy departure function. A more complete version of the energy equation is presented. The effects on flame structure, location, and peak temperature are analyzed for a range of pressure from 1-100 atm. Assessment of the different high-pressure corrections indicate that introduction of the cubic equation of state is the most profound adjustment, while the correction of transport properties is the least significant. The use of the enthalpy departure function is important. The flame structure and heat-release rate are confirmed to follow previously identified correlations with the pressure-weighted strain rate. Extinction occurs when the mass fraction of H 2 O vapor in the methane stream is greater than 67% and the mixture impinges against air. Small differences in results occur between the classical chemical equilibrium employing partial pressures versus the non-ideal formulation that uses fugacities. The Soret effect and radiative heat losses are shown to be negligible, even at the highest pressures. An order of magnitude analysis shows that turbulence generation is practically inconsequential.

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