PAPER making! FROM THE PUBLISHERS OF PAPER TECHNOLOGY INTERNATIONAL Volume 6, Number 1, 2020
Enhancement of drying of paper with phase change material: A numerical study, Alireza Mahdavi Nejad, International Journal of Heat and Mass Transfer, Vol.149 . This work numerically investigates the transport characteristics associated with the drying process of paper in the presence of a phase change material (PCM). The presence of PCM is studied in two different configurations: a layer of PCM embedded in the middle of paper and the PCM particles dispersed uniformly within the paper. This unique concept offers a new approach to paper drying by utilizing the latent-heat of fusion associated with the PCM, favorably impacting the energy efficiency of the drying process. The results indicate that the PCM acts as a heat source and a heat sink throughout the drying process, enhancing the drying rate. This study also includes the presence of an infrared emitter within the drying process. The corresponding absorption coefficient of PCM is measured experimentally. This paper is not concerned with the impact of presence of PCM on paper sheet properties. The proposed operating conditions and configuration presented here are solely for the purpose of illustration of the concept of drying in the presence of PCM. A sampling-based stochastic optimization for a boiler process in a pulp industry, Gustavo Matheus de Almeida et al, Korean Journal of Chemical Engineering, Vol.37(4) . Our Aim was to find the stochastic optimal solution for a boiler process in order to maximize steam generation while complying with pollutant emissions regulations. For a simulation base-model, support vector regression (SVR) is employed to present a general discrete-time dynamical system of a boiler, and a stochastic optimization was performed to take inherent process uncertainties into account. To generate a stochastic optimization problem, sample average approximation (SAA) based on Monte-Carlo sampling was introduced due to the properties of a SVR. Moreover, a gradient free-based particle swarm optimization (PSO) technique was applied to find the optimal parameters of SVR and investigate the stochastic optimal solution for the boiler process. The results show that the stochastic optimal solution provides almost 2% more steam generation under uncertainties: this indicates that the stochastic optimal solution provides more realistic results compared to the deterministic approach. The proposed methodology can be applied straightforwardly to black box models, or when the use of gradient-based optimization solvers is restricted. Multidimensional Interpolation Decoupling Strategy for CD Basis Weight of Papermaking Process, Wenjuan Shan & Bing Liu, Symmetry, 12(1) . With a focus on the multivariable coupling characteristics in a cross-directional (CD) basis weight control system, we study the coupling characteristics of a CD control system and decoupling control, and we propose a novel multivariable interpolation decoupling control strategy and a real-time decomposition algorithm in this paper. Based on a model of the CD basis weight profile, a system non-square interaction matrix of high-dimensional data is analyzed by experimental studies and numerical simulation. Along the diagonal of the interaction matrix, the matrix block method is adopted to reduce the system dimension and convert it into a square system. A multivariable control system with high dimensionality is divided into several subsystems. For the high-dimensional Toeplitz symmetric subsystem with small-scale coupling characteristics, an interpolation decoupling algorithm is proposed. Then, a decoupling compensator with the structure of a symmetric Toeplitz matrix was obtained. Compared with the conventional diagonal decoupling matrix, the branch number of the new decoupling network is reduced from 2408 to 186, which realizes the fast decoupling of multivariable systems. The results were even better when we used a double size interaction matrix obtained by interpolation between actual values. By designing the diagonalized controller for the new decoupled system, a decouped CD control system for
Technical Abstracts
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