基于Aspen Plus的超临界循环流化床锅炉特性分析

Exergy Analysis of Supercritical Circulating Fluidized Bed Boiler Based on Aspen Plus

为了探索超临界循环流化床锅炉的分布特性,利用Aspen Plus对350 MW超临界循环流化床进行建模,模型考虑了煤的热解燃烧过程、烟气换热以及灰循环过程,在燃烧过程中对密相区和稀相区的燃烧及换热分别进行建模,并通过该模型对循环流化床锅炉的分布特性和损失的影响因素进行了详细分析。结果表明:超临界循环流化床的效率为51.68%,循环流化床的循环灰较大,占密相区输入的52.43%。空气预热器的排烟损失较大,排烟损失为46.22 MW,占总输入的3.12%。分析可以更全面有效的揭示各种损失及损失发生的部分。

In order to explore the exergy distribution characteristics of supercritical circulating fluidized bed boilers,the 350 MW supercritical circulating fluidized bed（CFB）is modeled by Aspen Plus.This model considers the pyrolysis and combustion processes of coal,the flue gas heat exchange and ash circulation.The combustion and heat transfer in the dense and dilute phases were modeled respectively during the combustion process.The exergy distribution characteristics and the influencing factors of the CFB boiler were analyzed in detail.The results show that the exergy efficiency of the supercritical circulating fluidized bed is 51.68%,and the circulating ash exergy is greater,accounting for 52.43% of the input exergy in the dense zone.The exhaust exergy loss of the air preheater is 46.22 MW,which is3.12% of the total exergy input.Exergy analysis can be more comprehensive and effective to reveal a variety of exergy loss and exergy loss occurs part.