三效精馏优化专家系统的设计

将三效精馏流程分为5类,研究了进料温度、进料组成、进料相对挥发度对节能效率的影响。结果表明:三效精馏更适宜于进料相对挥发度小于6的物系,节能率可达50%以上;除逆流三效塔釜进料精馏适用于常温进料外,其余各流程均适用于泡点及以上温度进料;除顺流三效塔顶进料精馏外,其余各流程均适用于进料中轻组分摩尔分数大于重组分摩尔分数的情况。进料温度对节能率的影响比进料相对挥发度和进料组成要显著,是关键的影响因素。根据三效精馏节能规律,设计了三效精馏优化专家系统,本系统由用户界面、知识库和推理机3部分组成,其开发基于Windows XP操作系统,以Visual Basic 6.0作为开发工具,实现推理机对知识库的访问,实现VB 6.0与工程模拟软件(PRO/Ⅱ)之间的数据传输,从而实现对最优流程的智能选择,为三效精馏的应用设计、流程选择提供了平台。

Design of expert system for optimizing three-effect distillation

Three-effect distillation is classified into five different processes.The influences of feed-in temperature,feed-in composition and feed-in relative volatility on the energy-saving efficiency of three-effect distillation were researched through optimizing simulation by using PRO/Ⅱ.The results indicate that three-effect distillation is much suitable for the feeding fluid with a volatility of less than 6,and its maximum energy-saving efficiency is more than 50%.All processes are applicable to the conditions that the feed-in temperature is higher than bubble-point temperature,except for the backward-bottom-feed process that is used for the feeding at normal temperature.All the processes except for forward-overhead-feed process should be better used under the conditions that the feed-in composition has more light-component.The influences of feed-in temperature on energy-saving efficiency are more notable than feed-in composition and feed-in volatility.According to the variations of energy-saving efficiency,the expert system for optimizing three-effect distillation was designed.The system includes three parts of user-interface,knowledge-base and inference-engine.Based on the operation system of Windows XP,the system,developed by software of Visual Basic 6.0,realized the visit of inference-engine to knowledge-base and the data transport of VB 6.0 with PRO/Ⅱ.Then the optimum process of three-effect distillation can be selected.The expert system supplies the flat for the application design and process selection of the three-effect distillation.