98/03982 Method and assembly for increasing the capacity of a boiler plant

• Publisher: Elsevier Science
• Year: 1998
• Weight: 208 KB
• Volume: 39
• Category: Article
• ISSN: 0140-6701
• DOI: 10.1016/s0140-6701(98)93977-7

✦ Synopsis

08 Steam raising (boiler operation/design)

An eight-week test programme was carried out on a test burner with 2.5 MW thermal output in the IFRF test furnace in Ijmuiden, The Netherlands. The burner test was accompanied by numerical calculations and cold flow experiments. This led to the application of the burner in a utility boiler with a thermal capacity of 32 MW per burner, recommissioned in summer 1995 after retrofitting the burners. Burner operation performance did not experience problems. Experimental data are reported and the possibilities of adapting the burner to existing units are addressed.

9aio3971

Effect of pressure on char combustion in a pressurized circulating fluidized bed boiler MacNeil, S. and Basu, P. Fuel, 1998, 77, (4) 269-275. Under simulated pressurized circulating fluidized bed conditions, coal char combustion was studied at furnace temperatures between 700 and 850°C. At 1,3,5, and 7 atmospheres and oxygen concentrations of 10 and 21%, the kinetic rates of char combustion were measured. The surface reaction rates increased with pressure up to a pressure of 5 atm, but decreased with higher pressures. Pressure was found to exert a strong influence on the kinetic parameters.

The chars burned primarily under kinetically controlled conditions. Traditional char oxidation models cannot adequately predict the variation of reaction rates with pressures. Mass transfer rates were measured for comparison with those obtained from previous studies. These results show a marked difference in comparison with calculated values.