长网造纸机数学模型的开发

Development of the Mathematic Model for Fourdrinier Papermachine

造纸生产过程是一个复杂的传质传热过程。本文采用机理分析与测量辨识相结合的方法,建立了纸机的整机数学模型。该模型形式简单,又具有一定的准确度。据此模型设计的微机控制系统投入运行六年来已取得很大的经济效益,并深受厂方和操作工的欢迎。

Paper-making process is very complex with mass and heat transfer. It is very difficult to build a mathematic model of this process merely by mechanism analysis, and people often get it using identification techniques. The mathematic model built by identification is usually a imput-output model so that the inner states of papermaking process could not be obtained.In this paper, a mechanism analysis and identification combined method is used to build the mathematic model of a four-drinier paper-making process. The whole process is divided into four subsections: the pre-wire section, the wire and press section , the first drying section and the second drying section. For each subsection a submodel is built with its structure determined by mechanism analysis and its parameters identified from the daily record data. The four submodels together compose the global model of the process. This model with enough accuracy is simple, and the inner states can be obtained from it. The basis weight and moisture content system of the papermaking process based on this model has already made high economic benefits since its first operation more than six years ago.