Optimised dynamic control philosophy for improved performance of mine cooling systems

• Published in: Applied thermal engineering Vol. 150; pp. 50 - 60
• Main Authors: Crawford, J.A., Joubert, H.P.R., Mathews, M.J., Kleingeld, M.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 05-03-2019; Elsevier BV
• Subjects: Algorithms; Competitive; Cooling; Cooling systems; Dynamic; Dynamic control; Electricity; Electricity consumption; Electricity generation; Electricity pricing; Energy consumption; Energy costs; Gold; Mine cooling; Mine ventilation; Optimised; Reduction; Studies; Sustainability; Competitive; Dynamic; Optimised; Performance; Mine cooling; Sustainability
• ISSN: 1359-4311; 1873-5606
• DOI: 10.1016/j.applthermaleng.2018.12.160

•An integrated control strategy for improved mine cooling performance was employed.•An ambient DB temperature prediction model was developed, tested and implemented.•A dynamic temperature set point algorithm for chillers was formulated.•The dynamic control approach was validated on a South African mine cooling system.•Improved chiller COP was attained with no capital expenditure.
Mine workers require substantial cooling and ventilation to work in a safe and habitable environment. Deep level mine cooling systems were identified as significant energy-intensive consumers to supply such cooling. Mine cooling systems can make up to 25% of a mine’s total electricity consumption. Coupled with increasing electricity costs, deep level gold mines are struggling to remain competitive. Literature reveals a need for a simple and practical solution to optimise deep level mine cooling systems for improved system performance. In this paper, an optimised dynamic control strategy is presented to optimise the control of mine cooling systems. An integrated dynamic temperature set point algorithm and ambient dry-bulb (DB) temperature prediction model was formulated, implemented and verified. The optimised dynamic control model, when compared to existing control practises, attained a chiller coefficient of performance (COP) improvement and compressor power reduction of 7% and 4% respectively. Implementation results also showed a power demand reduction of 45.7% during the evening high electricity cost period. This strategy demonstrated to be simple and cost effective while showing significant performance improvements for South African mines.