Abstract

Modeling of the dryer section of a paper machine is of high importance in both designing and operation points of view. In this research, a novel thermodynamic and heat and mass transfer model has been introduced. The model is based on empirical equations of the literature and does not need fine discretization techniques such as finite difference method. The method used for calculation of convective heat and mass transfer coefficients of the dryer is a modification of the methods utilized in the literature. The trend of paper and air temperature in the dryer, the steam consumption of each cylinder, as well as the trend of drying process throughout the dryer has been calculated. Overall results of the dryer such as the total evaporated water and the specific steam consumption of the dryer have been obtained too. The results have been validated with experimental data of a previous research in the literature and show a relatively good agreement with the experimental data. Finally, the sensitivity of the results to some main parameters has been analyzed.

摘要

造纸机干燥部的建模在设计和操作方面都非常重要。在这项研究中，引入了一种新的热力学和传热传质模型。该模型基于文献的经验方程，不需要有限差分法等精细的离散化技术。用于计算干燥器的对流传热和传质系数的方法是对文献中使用的方法的修改。计算了烘干机内纸张和空气温度的变化趋势，每个滚筒的蒸汽消耗量，以及整个烘干机的干燥过程趋势。还获得了干燥机的总体结果，例如总蒸发水量和干燥机的比蒸汽消耗量。该结果已与文献中先前研究的实验数据进行了验证，并与实验数据具有较好的一致性。最后，分析了结果对一些主要参数的敏感性。