UBC Theses and Dissertations
Achieving energy efficiency and quality control during industrial veneer drying with data-driven approaches Qing, Qiu
Veneer drying plays an essential role in manufacturing veneer-based composites and consumes a significant amount of energy from burning fossil fuels, wood residues and electricity. The soaring energy price, the growing carbon tax rate, and the substantial social-environmental concerns regarding fossil fuel use have urged veneer manufacturers to adapt and become more efficient in energy consumption. Therefore, the ultimate objective of this research was to provide solutions for the industrial veneer drying process to reduce energy use without encumbering product quality. Unlike the physics-based methods commonly seen in the literature, this research embraced a data-driven approach for its promising potential in modelling a dynamic, complicated, and interrelated process such as veneer drying. In partnership with a veneer manufacturer in British Columbia, industrial drying data and climatic information corresponding to a several-month period were extracted, processed, compiled, and cleaned in two formats for analyzing unit energy consumption and drying quality turnout. Both parametric and non-parametric algorithms were deployed to predict the unit gas and electricity usage of each dryer. Based on cross-validation evaluations, the random forest model with all explanatory variables slightly outperformed two linear models regarding almost all accuracy metrics, but linear models had the advantage of providing an easy-to-interpret solution. In parallel, logistic regression classifiers and a random forest classifier were developed to estimate the quality level of individual veneer sheets, but the classification ability of all models was limited. Nonetheless, the results suggested that a more refined sorting of the initial moisture content of veneers could reduce unit energy consumption and lessen the number of re-dries and over-dries, thus improving quality turnout. Besides, the relations between unit energy consumption and Zone 1a temperature or drying speed were not consistent among different types of veneer products or between dryers, which posed challenges in modifying the veneer drying schedule for energy savings. Finally, models predicting energy consumption and veneer quality were combined in a preliminary assessment to optimize the drying schedule for reducing energy use.
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Attribution-NonCommercial-NoDerivatives 4.0 International