Simulation of Airflow Changes in a VOD System and Evaluation of Energy Benefits Through VREX Modeling
Gary Li, CanmetMINING, Natural Resourced Canada
The ventilation-on-demand (VOD) system has proven to be more efficient in operating the fans and supplying the amount of air corresponding to the mine activities taking place. To properly manage and evaluate such an advanced system, a dynamic modeling package VREX has been developed to simulate the mine activities in underground workings and determine the air volumes required to meet the distribution demand for a new production scenario. VREX incorporates the mine development data in the modeling through a discrete event simulation (DES) and solves the ventilation network using the CANVENT simulator. As the model tracks the air demand for equipment, it is able to assess the economic and environmental benefits for using electric and low emission vehicles in new and existing mine operations. A case study was performed to demonstrate the capabilities of the software and determine the potential energy savings for implementing VOD in a deep mine operation. A rules script is responsible for processing the production scenarios generated from the DES, applying the ventilation constraints for fans and regulators, and executing the ventilation solver to balance the network at each control time interval (CTI). The simulation results were analyzed to evaluate the performance of the network and determine the cost savings for operating the fan system based on air demand. It was concluded that the CTI should be 10 30 minutes to react the vehicle activities properly; the energy savings in operating the VOD system were 28%, compared to the results from a baseline model for a 31-day period; and the air demands for diesel engines dictated by regulations affected the total energy cost of the system.