面向对象方法在SPEEDUP中的应用

SPEEDUP是目前唯一采用面向方程法进行动态模拟的商品化软件，该软件也可对化工过程进行稳态模拟以及优化分析，是一个非常有前途的软件，但该软件使用起来很不方便，主要原因是输入困难。本文首次采用面向对象的方法在OOME（面向对象建模环境）下，为生成SPEEDUP的输入文件和建立新模型提供了一个很方便的接口，这可以促进SPEEDUP软件在我国的推广使用，为在线优化、控制提供良好的工具。结果表明，采用面向对象方法不仅程序层次清晰，而且复用度可比传统方法提高2－3倍。     

A simple approach to improve the robustness of equation-oriented simulators: Multilinear look-up table interpolators

Equation-oriented simulators have some advantages over the modular sequential ones, but improvements are still necessary to deal with nonlinearities, while preserving the robustness of the solver. Linear approximations and/or surrogate models can be used in place of nonlinear models, but the loss of predictive accuracy may be a drawback. An alternative to circumvent this problem is the use of grid-based look-up tables for interpolating responses from rigorous models. This methodology was integrated in an equation-oriented simulator (EMSO). A case study involving the production of bioethanol from sugarcane is used to demonstrate the robustness of this approach. Look-up tables replaced the models of two distillation column trains and of the cellulose hydrolysis reactor. These models were included into the global process and an optimization problem aiming at the maximum production of ethanol was successfully solved by a PSO algorithm varying the solid mass fraction in the hydrolysis reactor.     

Optimal design of extractive dividing-wall column using an efficient equation-oriented approach

The extractive dividing-wall column(EDWC)is one of the most efficient technologies for separation of azeotropic or close boiling-point mixtures,but its design is fairly challenging.In this paper we extend the hybrid feasible path optimisation algorithm(Ma Y,McLaughlan M,Zhang N,Li J.Computers&Chemical Engineering,2020,143:107058)for such optimal design.The tolerances-relaxation integration method is refined to allow for long enough integration time that can ensure the solution of the pseudo-transient continuation simulation close to the steady state before the required tolerance is used.To ensure the gradient and Jacobian information available for optimisation,we allow a relaxed tolerance for the simulation in the sensitivity analysis mode when the simulation diverges under small tolerance.In addition,valid lower bounds on purity of the recycled entrainer and the vapour flow rate in column sections are imposed to improve computational efficiency.The computational results demonstrate that the extended hybrid algorithm can achieve better design of the EDWC compared to those in literature.The energy consumption can be reduced by more than 20%compared with existing literature report.In addition,the optimal design of the heat pump assisted EDWC is achieved using the improved hybrid algorithm for the first time.     

Computer Simulation of Industrial Dryers

ABSTRACT

The use of computers to perform simulation of chemical engineering processes has lead to the development of software tools that Perform most tedious computations in the field of process analysis and design. The most popular Structures regarding process simulation of conventional and specialized processes are analyzed properly by considering the basic parts of commercial programs. Computational procedures. graphical aspects. management of properties database are outlined. Modeling aspects of drying technology regarding simulation are summarized and classified. The need for specialized software and development efforts in the field of commercial dryers simulation are enlohasized and nppropriately addressed. Moderm aspects. such as obiectoriented programming in simulation of industrial dryers are suitably presented and various case studies are used to indicate the effectiveness of modern simulation methods in the field of dryers operation.     

基于“场流”理论的面向对象建模方法初探

引　言工艺模拟开始进入面向方程法的时代[1].面向方程法在工艺设计和优化方面具有突出的优越性 ,然而基于面向方程法的软件一般必须由“专家”使用 ,普遍应用有较大限制 .在过程优化、动态仿真及复合过程 (如反应蒸馏和膜蒸馏等 )中应用面向方程法对建立充分透彻的过程模型也提出了更多要求[2 ].瓶颈在于传统的建模工具不能满足实际需要 ,模型可重用性不足[2～ 3].因此 ,计算机建模成为面向方程法亟需解决的最重要问题[4 ].当前解决建模问题的主要手段是面向对象技术[4～ 7].以面向对象技术为指导开发的商品化软件将代表物化关系的方程作为…     

面向方程联立求解的精馏塔模拟与优化一体化算法

在精馏塔机理模型的基础上,提出了面向方程联立求解的精馏塔模拟与优化一体化算法.精馏塔模型方程的特殊结构使得可以进行一定的变量分解和降维,采用面向方程联立求解的技术,使模拟计算和寻优搜索在同一层迭代中完成,避免了双层法每一步优化搜索都需进行模型收敛计算的缺点.从而大大提高了计算效率.同时,这样的联立法提供了一种开放式的统一框架.无论是模拟计算、操作优化还是设计优化都可以毫无困难地利用这个灵活的计算结构进行解算.文中用两个计算实例说明了这个方法的有效性.     

模拟常减压蒸馏装置的物性计算方法和模型结构

不同物性计算方法对常减压蒸馏装置的模拟,尤其对减压塔模拟的准确性影响较大。实践中常遇到模拟计算的减压渣油流量值低于现场实际数据。采用Aspen Plus软件,结合某炼油厂常减压蒸馏装置的标定数据,建立了联立方程法（EO）模型。在数据整定（Reconciliation）模式下,通过选用不同的物性计算方法和建立特殊的减压部分模型结构,给出了在Aspen Plus软件中模拟常减压蒸馏装置误差最小的物性计算方法,并从理论上解释了不同物性计算方法对常减压蒸馏装置模拟计算结果的影响。