面的辐射散热损失为994.5kJ/(h?m)。55.某600MW汽轮发电机组,锅炉主汽流量Gb=1823t/h,再热蒸汽流量Grh=1470t/h,主蒸汽焓为hms=3394.4kJ/kg,再热蒸汽冷端焓为hrh=3014.7kJ/kg,再热蒸汽热端焓为hrhr=3336.03kJ/kg,给水流量Gfw=1826t/h,给水焓hfw=1210kJ/kg,锅炉连续排污量Gb1=18t/h(汽包饱和水焓为hb1=1848kJ/kg),锅炉过热器减温水量Gss=34t/h,减温水焓tss=745kJ/kg,汽轮机热耗量为4688x106kJ/h,求锅炉热负荷和答案:(1)锅炉热负荷为[■IIMMGG-151■]=(1823×3394.4+1470×521.33+18×1848-1826×1210-34×745)×10[■IIMMGG-152■]=4752.82×10[■IIMMGG-153■](kJ/h)(2)管道效率[■IIMMGG-154■]答:锅炉热负荷为4752.82×106kJ/h,管道效率为98.64%。56.某600MW汽轮发电机组,汽轮机热耗率q=7813.33kJ/(kWh),锅炉热效率;ηb1=92.5%,管道效率ηgd=98.64%,求机组热效率、电厂热效率和发电煤耗。答案:(1)机组热效率为[■IIMMGG-155■](2)电厂热效率为[■IIMMGG-156■]=0.9864×0.925×0.4607=42.04%(3)发电煤耗率为[■IIMMGG-157■]答:机组热效率为46.07%,电厂热效率为42.04%,发电煤耗率为292.2g/(kWh)。57.某火电厂锅炉额定蒸发量为907t/h,发电机额定功率为300MW,烟煤收到基灰分Aar=17.5%,水分Mar=5.5%、,ar=23470kJ/kg,锅炉实际蒸发量为700t/h,飞灰可燃物Cfh=