低温省煤器联合暖风器在630 MW超临界机组锅炉烟气余热利用系统中的应用

Application of Low Temperature Economizer and Heater in Boiler Flue Gas Waste Heat Utilization System of 630 MW Supercritical Unit

燃煤锅炉过高的排烟温度不仅使锅炉效率大幅降低,而且使脱硫系统耗能、耗水加剧,导致除尘器效率下降,同时使得风机、除尘器寿命缩短。对一种低温省煤器联合暖风器的投用模式方案进行了分析。该方案通过回收排烟热量、加热凝结水及二次风,提高了锅炉效率。经测算,在设计工况下,该方案将降低发电煤耗约2.424g/kWh。测算结果论证了低温省煤器联合暖风器投用具有较高的热经济性和实施可行性。

Excessive exhaust smoke temperature of coal-fired boilers not only reduces boiler efficiency greatly,but also leads to more energy and water consumption of the desulfurization system,which reduces dust collector efficiency.Meanwhile,the life of the fan and the dust collector is shortened.A low-temperature economizer combined with air heater is analyzed,and the boiler efficiency is improved by recovering heat from smoke exhaust to heat condensate water and secondary air.According to calculation,this scheme will reduce the coal consumption of power generation by about 2.424 g/kWh under THA condition.The high thermal economy and feasibility of low-temperature economizer combined with air heater are demonstrated.