Benefits of improved performance monitoring of mine cooling systems

Abstract

Mine cooling system components are an integral part of a mine's ventilation system. A mine's reliance on these capital intensive components are set to increase as mines deepen. Mine cooling systems consume up to a quarter of the electricity used on mines. Component efficiency should be monitored to ensure optimum utilisation. Downtime should be minimised so that production is not negatively influenced. Replacing expensive components in an age of severe economic pressure should be avoided altogether. In this study, the performance of mine cooling system components was monitored. The effects of various operational and maintenance interventions on component performance have been quantified. Quantifying the effects of management decisions led to the refining of operational procedures, the optimisation of future maintenance, and the subsequent identification of electrical energy savings potential without the need for expensive modifications. Investigations show that a mine could realise a saving of up to nine hundred thousand rand annually by optimising the maintenance schedule of chillers. Extrapolated results estimate an electrical energy saving of 52 127 MWh per year if the strategy were implemented on twenty of South Africa's biggest mines. In addition, a monetary saving in excess of five hundred thousand rand could be saved through refining operational procedures. These strategies will be possible without the need for expensive installations or complicated modifications. Monitoring cooling system performance allows management to identify trends in performance, to understand component inter-dependence, and to allow for informed decision-making. In addition, performance monitoring allows for the identification of component and instrumentation faults. Statistical control charts and simulation modelling are some of the tools that have been employed in this study. These tools assist management formulate strategies and decisions with a higher degree of confidence.