Experimental evaluation of process parameters influencing ash deposition in pulverized coal-fired utility boilers and gas turbines

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6247946

Conn, R E

The tube furnace was capable of simulating most of the operating conditions of both utility boilers and gas turbines. A thin stream of pulverized coal was combusted in the furnace and the fly ash was impacted on metal substrates to form deposits. The results of these tests were then compared with a qualitative model involving (1) fly ash generation, (2) particle transport to a surface and (3) particle adhesion to the surface and deposit build-up. The generation of fly ash from a western U.S. lignite was proposed to occur by partial coalescence of mineral inclusions and organically bound metals in the char. Test results indicated that finer grinding of some low rank coals may reduce the interactions of inorganic constituents and fly ash particle size. For an eastern bituminous coal, it appeared that coalescence of minerals in the char did not occur. The dominant mechanism of particle transport to surfaces at conditions similar to utility boilers and gas turbines was observed to be by inertial impaction. The tube furnace was a simple system for studying the relationship between coal particle size and resultant fly ash particle size. The fly ash particle size distributions obtained in these tests can be utilized in aerodynamic models which predict collection efficiencies of boiler and gas turbine surfaces. The retention of fly ash particles which impacted upon a metal surface was enhanced by the presence of a liquid phase on either the fly ash particles or on the metal surface. In tests simulating both boilers and gas turbines, the amount of deposition and strength of deposits were found to be inversely proportional to the viscosity of liquid specie predicted to occur at chemical equilibrium.

• Research Organization: Pennsylvania State Univ., Middletown, PA (USA)
• OSTI ID: 6247946
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010800 -- Coal
Lignite
& Peat-- Waste Management
014000* -- Coal
Lignite
& Peat-- Combustion
20 FOSSIL-FUELED POWER PLANTS
200202 -- Fossil-Fueled Power Plants-- Waste Management-- Noxious Gas & Particulate Emissions
ADHESION
AEROSOL WASTES
ASHES
BENCH-SCALE EXPERIMENTS
BITUMINOUS COAL
BLACK COAL
BOILERS
BROWN COAL
CARBONACEOUS MATERIALS
CHEMICAL REACTION KINETICS
COAL
COAL-FIRED GAS TURBINES
COALESCENCE
COMBUSTION KINETICS
COMMINUTION
CRYSTALS
DEPOSITION
DEPOSITS
DISTRIBUTION
ENERGY SOURCES
ENERGY TRANSFER
FLUIDS
FLY ASH
FOSSIL FUELS
FOSSIL-FUEL POWER PLANTS
FOULING
FUELS
FURNACES
GAS TURBINES
HEAT TRANSFER
KINETICS
LIGNITE
LIQUID CRYSTALS
LIQUIDS
MACHINERY
MASS TRANSFER
MATERIALS
MINERALS
PARTICLE SIZE
POWER PLANTS
PULVERIZED FUELS
REACTION KINETICS
RESIDUES
SIZE
SUBBITUMINOUS COAL
SYNTHESIS
THERMAL POWER PLANTS
TURBINES
TURBOMACHINERY
WASTES