蒸汽抽取位置对抽蒸汽干化污泥耦合发电机组影响

Effects of steam extraction position on sludge-coal blending combustion generating unit

为了掌握蒸汽抽取位置对抽蒸汽干化污泥耦合发电燃煤机组运行参数的影响,针对某电厂300 MW等级燃煤机组,以能量守恒定律为基础,通过锅炉热力校核和机组热力系统计算分析了机组在BMCR、90%THA、75%THA、50%THA和30%THA工况下,从不同位置抽蒸汽干化污泥掺烧后的锅炉热效率、发电煤耗、燃煤量、烟气温度、烟气量及减温水量等参数的变化。结果表明:掺烧污泥会导致锅炉主要运行参数的恶化,变化幅度随着负荷的降低和湿污泥处理量的增加而增大;高负荷时从四抽抽汽对机组煤耗影响较小,中负荷从三抽抽汽对机组煤耗影响较小,低负荷只能选择再热器冷段作为抽汽点。

In order to study the influence of steam extraction location on operation parameters of the coal-fired boiler co-firing steam desiccation sludge,thermal calculation for boiler and thermal system of a 300 MW coal-fired power unit was carried out in this paper,based on the energy conservation equation.Under the load of BMCR,90%THA,75%THA,50%THA and 30%THA,the boiler parameters such as boiler thermal efficiency,coal amount of the unit,coal consumption,flue gas temperature,gas flow and spray water flux were studied when the sludge dried by steam extracted from different positions were blended.The results show that,blending sludge would cause deterioration of boiler main parameters,and the variation range increased with the decrease of unit load and growth in wet sludge treatment capacity.At high load,steam extraction from the fourth-stage extraction point of steam turbine had little effect on coal consumption of the unit.At middle load,steam extraction from the third-stage extraction point of the steam turbine had little effect on coal consumption of the unit.At low load,cold reheat steam pipe could only be selected as extraction point.