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Energy audit of mine refrigeration water systems by means of simulation. 16 August 2012 Dr. Herman van Antwerpen Pr.Eng M-Tech Industrial. Introduction. Purpose of this paper: Demonstrate the benefits of integrated system simulation,
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Energy audit of mine refrigeration water systems by means of simulation 16 August 2012 Dr. Herman van AntwerpenPr.Eng M-Tech Industrial
Introduction • Purpose of this paper: • Demonstrate the benefits of integrated system simulation, • Its use in energy assessment of a mine refrigeration system. • Type of simulation: • Conservation of mass, energy and momentum at system level, • i.e. flow rates, temperatures and pressures
Motivations for simulating a system • On a new design: • Do component sizing • Verify component selection, control philosophies, etc. • On an existing plant: • Compile the data set that describes system operation • Develop good understanding of system operation • Check instrumentation consistency / high-level fault finding • Assess changes at a system-level • Identify savings opportunities: survival of deep mines
Classification of loads and savings Peak load Energy efficiency Baseload “DSM valves”
Water distribution system Manos Engineering, Welkom
Network for level Network for level Network for level Network for level
Required phenomena • Elevation differences • Cooling car characteristics • Heat pickup along pipes in haulages
Chilled water heating along haulages Journal of the SA Institute of Mining and Metallurgy: Rawlins, C.A. (2007) “Mine cooling and insulation of chilled water transport pipes” Jones, M.Q.W. (2003) “Thermal properties of stratified rocks from Witwatersrand gold mining areas”
Cooling car control 25ºC Reference data With thermostatic control
Conclusions • Regarding mine refrigeration • Opportunity: “Mine-proof” cooling car flow control. • For some mine layouts: • Minimum refrigeration cost: highest possible chilled water temperature. • Constraint: cooling car inlet pressure. • Regarding simulation • Industrial Energy Efficiency projects or system-level optimisation requires integrated simulation: flow rate, temperature and pressure.
Acknowledgements Questions?