摘要
基于能量梯级利用的原理提出了一种新型的污泥干化焚烧余热回收系统,充分利用了污泥焚烧后烟气中的高温热量,同时能满足焚烧炉和干化机运行的条件。相比于常规的污泥干化焚烧系统,新系统在干化机后增加了换热单元,充分利用了蒸汽中热量,提升了进焚烧炉污泥的热值;通过设置两级余热锅炉以及调整空气预热器的换热位置,改善了空气预热器和余热锅炉中存在的较大换热温差。基于某污泥干化焚烧项目的设计参数建立了热力计算模型,并基于热力学第二定律建立了余热回收系统的热力性能评价指标,结果显示:随污泥中可燃质含量的增加,余热回收系统的火用效率升高;相比于常规系统,新系统的热力学火用效率提升了1.72%,由于蒸汽品质得到提升并且用于小汽机做功,运行经济性得到提升。
Based on the principle of gradient utilization of energy,a novel heat recovery system of sludge incineration process fully utilizing the high quality thermal enegy is proposed in this paper,which can fufill the operating conditions of incinerator and dryer.Compared to conventional sludge drying incineration system,a heat transfer unit is added to the outlet of sludge dryer in the new system,which will fully utilize the amount of heat that the steam carries and increase the heat value of dried sludge.Through the setting of two-stage heat recovery steam generator and adjusting the position of air pre-heater,high temperature differentials in air pre-heater and heat recovery steam generator have been improved.Thermal model is established based on design conditions of a specific project and thermodynamic performance index of the heat recovery system has been proposed based on the second law of thermodynamics.The result shows that with the increase of the combustible compound of the sludge,exergy efficiency of the heat recovery system is improved correspondingly.Compared to conventional system,the new system has an exergy efficiency increment of 1.72% and the operation cost is improved due to the stream parameter enhancement and power generation.
作者
刘宇佳
王飞
赵旭东
LIU Yu-jia;WANG Fei;ZHAO Xu-dong(Tongfang Environment Co.Ltd.,Beijing, 100083,China;State Key Laboratory of Clean Energy Utilization,Zhejiang University,Hangzhou,310027,China)
出处
《热能动力工程》
CAS
CSCD
北大核心
2020年第5期245-252,共8页
Journal of Engineering for Thermal Energy and Power
基金
国家自然科学基金(91741203)
浙江省科技计划项目(2018C03041,2018C03007)。
关键词
污泥焚烧
余热回收系统
热力建模
热力分析
sludge incineration
heat recovery system
thermal modeling
thermodynamic analysis
