Using specific energy as a metric to characterise compressor system performance

Mine compressed air systems are inefficient and complex to analyse. There is no clear method which can be used to characterise the total performance of the supply side system in terms of the air supplied and energy consumed. A simplified and unbiased performance measuring method was lacking from research. An important implication of this study was to develop a simplified method which uses a single metric to determine the performance of a compressed air system relative to the compressor air supply and energy consumption. This metric used minimal information and can be used as a guide to improve performance as well. A compressed air system was analysed before and after project implementation, using the simplified method. The simplified method gave a good indication of the performance change as projects were implemented on the compressed air system, with an improvement of 6% on the average total specific energy from 104 to 98 Wh/m3. The off-peak specific energy decreased from 103 to 94 Wh/m3 which illustrates a 9% improvement. This study showed the possibility to characterise the performance of complex compressed air systems using a simplified metric. It can also be utilised to verify whether supply side initiatives were effective.