某600 MW超临界锅炉综合降排烟温度改造方案及节能效果

Scheme and Energy-saving Effect of Exhaust Temperature Reduction Modification for 600MW Supercriticai Boiler

针对某600 MW超临界锅炉实际情况,介绍了实现全负荷脱硝和大幅度降低排烟温度提升经济性能的综合技术改造方案,论述了水媒烟气/空气换热器系统的节能原理和措施,并对锅炉完成改造后的实际运行情况和效果进行了说明。方案大幅度降低锅炉排烟温度20~30℃,并满足全工况脱硝要求,采用机炉耦合方式实现不同季节、不同负荷、不同煤种,在保证低温受热面安全的情况下自动调整锅炉排烟损失与汽机冷端损失,维持机组经济性能,增加了锅炉适应运行条件变化的能力。在相同末端受热面低温腐蚀及堵灰条件下,环境温度越低、煤种腐蚀性越强,本方案的节煤潜力越大。

Accordingto theactual situationofa6ooMW supercritical boiler,a comprehensivemodification schemeto achieve full load denitration and greatly reduce exhaust gas temperature is introduced.The energy saving theory and method of water medium flue gas/air heat exchange system are expounded,the actual effect of the modification is described.The modification scheme greatly reduced the boiler exhaust gas temperature by 20-30℃,achieved full load denitration and automatically adjusted boiler exhaust loss and turbine cold end loss to maintain unit economic performance under different seasons,loads and coal types on the premise of ensuring the safety of low-temperature heating surface,increased the ability to adapt to changes in operating conditions.Under the same conditions of low temperature corrosion and ash blockage of the last heating surface,the lower the ambient temperature is and the stronger the corrosivity of coal is,the greater the coal saving potential of this scheme will be.