提高空气入炉温度对芳烃加热炉能耗的影响

Impact of elevated inlet air temperature on energy consumption of aromatic heater

芳烃联合装置产生的0.72 MPa,167℃凝结水直接送出装置,这部分余热没有充分利用。通过以加热炉区的凝结水为热源加热鼓风机出口空气来回收凝结水余热,同时提高空气进入炉膛的温度。以加热炉系统为计算实例,采用对数平均温差法,探讨了芳烃联合装置加热炉系统提高空气进空气预热器温度后的空气入炉温度、排烟温度、加热炉综合热效率及节约燃料气量的变化情况,最终得出结论:当温度提高50℃时,每年可多回收热水余热2 196.70 kW,节约燃料气量1 509.30 t,余热回收率达34.4%。

The condensate water of 0.72 MPa pressure and 167℃ temperature of an aromatic complex is directly sent out of the unit without recovery of waste heat. This paper provides a study on using the condensate water from heater area as the heat source to heat up the air from outlet of air blower to recover the waste heat from condensate water and raise the inlet air temperature of the heater. In a case study of F-401 heater and by application of logarithmic mean temperature method, the changes of inlet air temperature of heater, flue gas emission temperature, thermal efficiency of heater and saved fuel gas after raising air temperature of air preheater of heater system in aromatic complex are explored. It is concluded that, when the temperature is elevated by 50 ℃, the annual recovery of waste heat from hot water is 2 196.70 kW, the saved fuel gas is 1 509.30 tons and waste heat recovery is 34.4%.