Abstract:
In the current situation of the energy crisis, the mining industry has been identified as a promising area
for application of demand side management (DSM) techniques. This paper investigates the potential for
energy-cost savings and actual energy savings, by implementation of variable speed drives to ventilation
fans in underground mines. In particular, ventilation on demand is considered in the study, i.e., air volume
is adjusted according to the demand at varying times. Two DSM strategies, energy efficiency (EE)
and load management (LM), are formulated and analysed. By modelling the network with the aid of
Kirchhoff’s laws and Tellegen’s theorem, a nonlinear constrained minimization model is developed, with
the objective of achieving EE. The model is also made to adhere to the fan laws, such that the fan power at
its operating points is found to achieve realistic results. LM is achieved by finding the optimal starting
time of the mining schedule, according to the time of use (TOU) tariff. A case study is shown to demonstrate
the effects of the optimization model. The study suggests that by combining load shifting and energy
efficiency techniques, an annual energy saving of 2540035 kW h is possible, leading to an annual cost
saving of USD 277035.