基于机械蒸汽再压缩的两级污泥干化系统的模拟研究

A numerical study of the two-stage sludge drying system based on mechanical vapor recompression

提出一种基于机械蒸汽再压缩的两级污泥干化系统,用于解决市政污泥深度热法干化处理中存在的二次蒸汽利用率低和"黏滞区"污泥的黏结问题。以某污水处理厂经过机械脱水预处理后的污泥为例,采用Aspen Plus软件建立相关工艺流程模型,通过模拟计算验证工艺的可行性,并探究第一段干化系统污泥出口含水率对系统能耗及外来补充蒸汽量的影响。模拟结果表明:二次蒸汽的潜热及显热得到高效利用,关键参数满足设计要求,工艺流程具有可行性;随着第一段干化系统污泥出口含水率的增加,压缩机电耗降低,加热装置能耗增加;当含水率高于60%时,此时系统需要补充外来蒸汽才能维持运行。

A two-stage sludge drying system based on mechanical vapor recompression,which is used to solve the low secondary steam utilization rate and the adhesion of sludge in the"viscosity zone"in the deep thermal drying treatment of municipal sludge problem.Taking the sludge pretreated by mechanical dehydration in a sewage treatment plant as an example,the Aspen Plus software was used to establish the relevant process flow model,and the feasibility of the process was verified through simulation calculation,and the water content at the sludge outlet of the first stage drying system was explored.The influence of the rate on the energy consumption of the system and the amount of external supplementary steam.The simulation results show that the latent heat and sensible heat of the secondary steam are efficiently used,the key parameters meet the design requirements,and the process flow is feasible;as the moisture content of the sludge outlet of the first stage drying system increases,the compressor power consumption decreases,and the heating device increases.When the water content is higher than 60%,the system needs to supplement external steam to maintain operation.