Combustion of coal/water mixtures with thermal preconditioning. Final report
Thermal preconditioning is a process in which coal/water mixtures are vaporized to produce coal/steam suspensions, and then superheated to allow the coal to devolatilize producing suspensions of char particles in hydrocarbon gases and steam. This final product of the process can be injected without atomization, and burned directly in a gas turbine combustor. This paper reports on the results of an experimental program in which thermally preconditioned coal/water mixture was successfully burned with a stable flame in a gas turbine combustor test rig. Tests were performed at a mixture flowrate of 300 lb/hr and combustor pressure of 8 atmospheres. The coal/water mixture was thermally preconditioned and injected into the combustor over a temperature range from 350 to 600/sup 0/F, and combustion air was supplied at between 600 to 725/sup 0/F. Test durations generally varied between 10 to 20 minutes. Major results of the combustion testing were that: a stable flame was maintained over a wide equivalence ratio range, between phi = 2.4 (rich) to 0.2 (lean); and, combustion efficiency of over 99% was achieved when the mixture was preconditioned to 600/sup 0/F and the combustion air preheated to 725/sup 0/F. Measurements of ash particulates captured in the exhaust sampling probe located 20 inches from the injector face, show typical sizes collected to be about 1 micron, with agglomerates of these particulates to be not more than 8 microns. The original mean coal particle size for these tests, prior to preconditioning was 25 microns. System studies indicate that preconditioning can be incorporated into either stationary or mobile power plant designs without system derating. On the basis of these results, thermal pretreatment offers a practical alternative to fuel atomization in gas turbine applications. 20 figs., 4 tabs.
- Research Organization:
- General Applied Science Labs., Inc., Westbury, NY (USA)
- DOE Contract Number:
- AC21-84MC21390
- OSTI ID:
- 5060511
- Report Number(s):
- DOE/MC/21390-2025; ON: DE86006153
- Resource Relation:
- Other Information: Portions of this document are illegible in microfiche products. Original copy available until stock is exhausted
- Country of Publication:
- United States
- Language:
- English
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Combustion of coal/water mixtures with thermal preconditioning
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FUEL SLURRIES
COMBUSTION
EVAPORATION
SUPERHEATING
AIR HEATERS
ATOMIZATION
COAL
COMBUSTORS
DEVOLATILIZATION
FUEL-AIR RATIO
GAS TURBINES
MEDIUM PRESSURE
MIXTURES
WATER
CARBONACEOUS MATERIALS
CHEMICAL REACTIONS
DISPERSIONS
ENERGY SOURCES
FOSSIL FUELS
FUELS
HEATERS
HEATING
HYDROGEN COMPOUNDS
MACHINERY
MATERIALS
OXIDATION
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
SLURRIES
SUSPENSIONS
THERMOCHEMICAL PROCESSES
TURBINES
TURBOMACHINERY
014000* - Coal
Lignite
& Peat- Combustion