3. METSIM requires the engineer to develop a detailed understanding of the process and provides a format for evaluating process design criteria.
METSIM 需要工程师逐步深入详细地理解工艺过程，并提供一个可用于 评估工艺设计标准的开本。
Some advantages of using METSIM are: 使用 METSIM 的优点：
1. Computer simulation is less costly than operating a pilot plant. 计算机模拟的成本低于半工业试验工厂
2. METSIM facilities extrapolation and scale-up of process options. METSIM 便于按比例扩大工艺参数
METSIM originated as a metallurgical process simulation program, written to perform mass balances around the major unit operations of complex process flowsheets. Application of the program proved so successful that it was expanded to include detailed heat balances, chemistry, process controls, equipment sizing, cost estimation, and process analysis. The unique nature of the programming language, APL, allows modification and expansion of the system with minimum effort and permits the incorporation of continuing technological innovations in process simulation. METSIM 起初是一种为了进行复杂工艺流程（图）主操作单元的物料平衡计算而编 写的冶金过程的模拟程序软件。该程序软件的应用取得了极大的成功，（以至于）它 被扩展到包括详细热平衡、化学、过程控制、设备规格、投资估算和过程分析。独 特的程序设计语言 APL 允许不需要花费大力气就可以使得系统得到修订和扩充，同 时也允许在过程模拟方面连续不断的创新和积累。
3. Pilot plant data evaluation. 半工业试验工厂数据评估
4. Full scale plant design calculations. 全比例工厂设计计算
5. Operating plant improvement studies. 生产运行工厂改进研究
6. Actual plant operations. 现行工厂的操作
供了各种组成单元所需要的详细数据和在 METSIM 程序中输入过程模型数据的方 技巧。
METSIM provides the power of the largest computers with the complexity of advanced engineering mathematics. METSIM was designed to take full advantage of the work space characteristics, interactive capabilities and functional power of APL. The need for complicated job control language, file handling, text editing, and debugging programs has been eliminated. METSIM 提供了采用复杂而先进的工程数学方法的强大计算机能力。在特有的工作 空间、交互能力和 APL 的函数其余求解能力上，METSIM 具有全面的优势，免除 了对复杂工作控制语言、文件处理、文本编辑和调试程序方面的要求。
1. Introduction
引言
The basis for analysis of all chemical and metallurgical processes is the mass and energy balance. Plant design, capital costs, and technical evaluations are all dependent on such calculations. METSIM is a general-purpose process simulation system designed to assist the engineer in performing mass and energy balances of complex processes. METSIM uses an assortment of computational methods to effect an optimum combination of complexity, user time, and computer resources usage. 根据分析和研究，所有化学的和冶金的反应过程都是质量平衡和能量平衡的。工厂 设计、投资成本以及技术评估都是基于这样的计算。MWTSIM 是一种多用途工艺过 程模拟系统，该系统的建立是为了帮助工程师进行复杂工艺过程质量和能量平衡计 算。METSIM 使用一系列计算方法以实现复杂性、用户时间以及计算机等各种使用 的资源得到合理地优化。
In conformance with the sequential modular approach, METSIM comprises modules containing subsets of equations describing the design specifications and performance characteristics for each process step. The system solves the equation subset for each module, allowing for an individual analysis of each unit operation in the flow-sheet. Given data on design variables and input stream composition, each module calculates all of the output stream variables, which can then be used as input stream values for the next process step. The modules access data on all independent stream variables from the data arrays contained within the APL global workspace. Additional input data required to solve the equations in each module are requested by the program and are stored as global variables. The user may supply actual data obtained from operating or pilot plants, from similar processes, or from estimates supplied by the engineer. 与连续数模逼近法一致，METSIM 由数模所组成，这些数模含有设计规范描述的子 集和每一步工艺过程执行特性。该系统求解每一个模块的方程子集，允许对流程中 的每一个操作单元进行单独地分析。给定数据关于设计变量，输入物料流组成成分， 每一个模块计算产出物流变量，这些输出的物料流再作为下一个工艺单元的输入物 料流。模块存取所有独立的物流变量数据均来自包含在 APL 语言的整个工作空间 （the APL global workspace）的数据矩阵。为了求解模块的方程式，程序需要另外 附加输入数据，并被储存为全局变量。用户可以提供从操作或试验工厂、类似工艺 过程，或从工程师提供的评估报告中获得的数据。
METSIM performs mass and energy balances for chemical processes using the sequential modular approach. This method is used because of its elegance and to simplify divers and complex flowsheets. METSIM can easily be expanded to encompass new processes and techniques. A major advantage of this approach is that intermediate results may be obtained from any stage of the process in an intelligible form. This attribute of METSIM is invaluable when attempting to detect possible modeling or specification errors. METSIM 为化学过程进行物料的和热量的衡算采用的是连续数模逼近的方法。之所 以采用这种方法是因为它方法巧妙和对种种复杂的流程能简单化一。METSIM 能够 简单方便地扩展应用于新工艺和新技术。这种逼近法的最主要的优点是能够以可理 解的形式获得任意一个中间过程的数据。METSIM 这一特征的价值是无法估量的， 尤其是在试图查找问题模型和说明书的错误时。