Measurements and computer calculations of pulverized-coal combustion at Asnaes Power Station 4

摘要

Measurements have been performed on a front-fired 270 MW (net electrical out-put) pulverized-coal utility furnace with 24 swirl-stabilized burners, placed in four horizontal rows. Apart from continuous operational measurements, special measurements were performed as follows. At one horizontal level above the upper burner row, gas temperatures were measured by an acoustic pyrometer. At the same level and at the level of the second upper burner row, irradiation to the walls was measured in ten positions by means of specially designed 2 (pi)-thermal radiation meters. Fly-ash was collected and analysed for unburned carbon. Coal size distribution to each individual burner was measured. Eight different cases were measured. On a Columbian coal, three cases with different oxygen concentrations in the exit-gas were measured at a load of 260 MW, and in addition, measurements were performed at reduced loads of 215 MW and 130 MW. On a South African coal blend measurements were performed at a load of 260 MW with three different oxygen exit concentrations. Each case has been simulated by a three-dimensional numerical computer code for the prediction of distribution of gas temperatures, species concentrations and thermal radiative net heat absorption on the furnace walls. Comparisons between measured and calculated gas temperatures, irradiation and unburned carbon are made. Measured results among the cases differ significantly, and the computational results agree well with the measured results. (au)