基于Aspen Plus平台与CFD技术相结合的反应精馏模拟研究

采用过程系统模拟软件Aspen Plus对反应精馏过程进行了模拟计算,与计算流体力学CFD软件的模拟结果进行了对比.然后,根据2种软件的特点,将Aspen Plus的模拟结果有选择性地作为输入变量导入CFD软件中,进行再次模拟,2种软件模拟结果吻合较好.最后,以干气制乙苯的反应精馏过程为例说明上述模拟研究.     

Strategy for Synthesis of Flexible Heat Exchanger Networks Embedded with System Reliability Analysis

System reliability can produce a strong influence on the performance of the heat exchanger network (HEN). In this paper, an optimization method with system reliability analysis for flexible HEN by genetic/simulated annealing algorithms (GA/SA) is presented. Initial flexible arrangements of HEN is received by pseudo-temperature enthalpy diagram. For determining system reliability of HEN, the connections of heat exchangers(HEXs) and independent subsystems in the HEN are analyzed by the connection sequence matrix(CSM), and the system reliability is measured by the independent subsystem including maximum number of HEXs in the HEN. As for the HEN that did not meet system reliability, HEN decoupling is applied and the independent subsystems in the HEN are changed by removing decoupling HEX, and thus the system reliability is elevated. After that, heat duty redistribution based on the relevant elements of the heat load loops and HEX areas are optimized in GA/SA. Then, the favorable network configuration, which matches both the most economical cost and system reliability criterion, is located. Moreover, particular features belonging to suitable decoupling HEX are extracted from calculations. Corresponding numerical example is presented to verify that the proposed strategy is effective to formulate optimal flexible HEN with system reliability measurement.     

考虑系统可靠性分析的柔性换热网络综合

基于虚拟温-焓图法与遗传/模拟退火算法,提出了一种考虑系统可靠性水平的柔性换热器网络综合方法。为简化求解问题的复杂度,首先通过虚拟温-焓图法得到了柔性网络匹配,对于得到的网络结构,通过网络结构的连接矩阵分析网络之中的连接状况,搜索出换热网络中存在关联的换热器单元,以关联的换热器作为主线识别出网络之中不相关的子系统,根据包含换热器单元个数最多的不相关的子系统含有换热器的数量,计算出换热网络系统的可靠性。对于未能满足网络系统可靠性要求的网络结构,通过去掉与其它换热器相关联总数最多的换热器,进行网络解耦,改变换热网络的关联状况,提高了系统的可靠性。换热网络结构改变后,采用遗传/模拟退火算法对热负荷回路中相关换热器的热量分配和换热面积进行计算,得出满足系统可靠性需求,并且总费用最为节约的网络结构。本文所提出的方法可以将需要改善系统可靠性的网络结构系统可靠性提高至设计的容许范围,适用于包含系统可靠性分析的柔性换热网络综合。计算实例表明了所提方法的实用性与可行性。     

骨架镍催化环戊酮液相加氢动力学研究

用骨架镍催化剂对环戊酮液相加氢动力学进行研究.分别考察该催化剂体系的加氢活性和加氢速率.经加氢实验表明,该催化剂对环戊酮加氢的较佳工艺条件为:氢气压力3.5 MPa,温度190℃,可使环戊酮加氢转化率大于90%.根据实验数据进行参数估算,求得各影响因素的动力学模型参数,并得到该催化剂的加氢动力学方程:-dc环戊酮/dt=kc环戊酮pH22.经统计检验表明,所得动力学模型较为合适.反应温度160-190℃时的加氢反应活化能为42.53 kJ/mol.反应速率常数为287.798 exp(-42 530/RT).