Modelling techniques to minimise operational costs in energy intensive industries / Jan Adriaan Swanepoel
| Autor: | Swanepoel, Jan Adriaan |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Druh dokumentu: | Diplomová práce |
| Popis: | Energy cost savings are key for South African industry to remain competitive in an international market. The South African gold-, platinum, and cement industries are three such examples. Recent electricity price increases have forced these industries to focus on reducing operational costs. Various methods of energy cost reduction are utilised in modern industry, usually with extended payback periods. Efficient operation planning and optimisation can however reduce energy costs with instant payback. Operations modelling and computer-assisted optimisation allow plant personnel to schedule plant activities more effectively. Most literature steers research towards the modelling of specific applications, instead of widening the analysis for application on various systems. As a result, and due to the complexity of these modelling techniques, modelling and operations interventions are costly, as they are mostly implemented by expert personnel and consultants. This thesis presents the compilation of integrated modelling techniques that simplifies modern methods. The simplification makes widespread implementation by less knowledgeable personnel possible. Unique component descriptions are developed that reduce the complexity of the mathematical representation of the real-world plants. New process- and link component descriptions are generated. These describe real-world components accurately which are flexible to characterise a multitude of plant designs. As part of the study, a new continuous-time modelling approach was generated that reduces processing time. This time modelling approach is flexible to optimise any extent of time, using a continuous-time approach. This new optimisation and scheduling algorithm calculates lowest cost operations while considering continuously variable plant settings and interlinked component response, such as buffer levels. The modelling techniques are implemented using an automated energy management system. The new techniques are compared to existing linear optimisers and show a reduction in processing time and complexity. The thesis describes the application of the modelling techniques on four cement production plants and generated energy cost savings of more than 10%, or R8.5 million p.a.. Further benefits include higher production outputs, improved product quality and the reduction of operational risks. The application on gold mining, platinum concentration and ore distribution logistics are also investigated. Industrial processes are simulated to determine the savings potential of the new modelling techniques and the effectiveness of managing operations by integrated modelling of a system of components. The modelling technique is simple enough for plant personnel to compile. Conclusively, the new modelling techniques showed general energy savings of up to 6% and large potential for industry-wide cost savings, accounting for up R100-million p.a. in the considered South African businesses. PhD (Mechanical Engineering), North-West University, Potchefstroom Campus, 2015 |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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