电站锅炉省煤器设计与改造对过热汽温的影响

根据锅炉蒸发受热面工质侧产汽量与过热汽温之间的内在依赖关系 ,从热量和质量平衡原理出发 ,讨论了自然循环锅炉给水温度不变而省煤器出口水温偏离设计值时对过热汽温间接的影响规律。在电站锅炉尾部受热面的改造或设计中 ,为考虑其它因素而不得不改变省煤器的吸热量时 ,建议将锅炉烟气侧热力计算与工质侧的吸热产汽量计算结合起来 ,验算省煤器出口水温的变化对炉膛蒸发受热面工作以及过热汽温的影响。

Effect of Economizer Heat Transfer Design and Retrofitting on Superheated Steam Temperature for the Utility Boiler

According to internal relations between steam production of the evaporator and superheater steam temperature, indirect effect of economizer exit water temperature variation on superheated steam temperature at boiler exit are discussed based on heat and mass balance. It is proposed that in the designing or retrofitting of economizer, if heat transfer surface have to be changed it is necessary to implement the thermal calculation in both flue gas side and water/steam side. The calculation emphasizes on the effect of water temperature variation at economizer exit of evaporator working condition and superheated steam temperature.