Automatic control of the coal mining drainage installation taking into account the trison tariff for electricity

Abstract

Objective is to reduce the specific energy consumption for dewatering in coal mines by minimizing time intervals of the switched-on pumps during the peak load hours when the electric energy cost reaches its maximum. Research methodology. Simulation modelling of water pumping from a water intake facility at a mining enterprise has been used to study automotive control of a water-removal plant. In this context, simulation of the whole system of automatic control is performed involving the proposed algorithm of pump switching on/off in terms of the criteria of entering the peak load hours according to the seasonal electric energy tariff with minimal water level in a water intake facility. The simulation modeling has helped analyze the effect of changeable characteristics of water inflow into the water intake facility upon the water level at the moment of entering the peak load hours to prove the efficient operation of the automatic control system according to the proposed algorithm with the help of simulation modelling. Findings. The carried out analysis of the operation of an automatic system to control a dewatering plant according to the proposed control algorithm has proved the efficiency of the use of a movable pump with the determination of its switch-on time on the basis of prognosis of water level dynamics in a water intake facility taking into account the pump characteristics and water inflow to provide minimal water level in a water intake facility at the moment of entering the peak load hours. The conditions of getting more positive effect from the use of the proposed algorithm for the dewatering plant control have been specified depending on the pump characteristics and water inflow. Originality. The time necessary for a movable pump for dewatering aimed at entering the “peak load hours” zone with the minimal water level in a water intake facility is directly proportional to the difference between the current water volume in a water intake facility and the water volume, corresponding to a minimal level, and inversely proportional to the movable pump output as well as the rate of current water volume increment in a water intake facility. In this context, it has been identified that in terms of the transfer from the available control algorithm to the proposed one, the value of reduction of the consumed electric energy costs and the pumped water costs is in direct proportional dependence upon the duration of time intervals of the switched-on states of main pumps – the shorter that duration is, the longer time interval of the operation of main pumps during the peak load hours is, and, correspondingly, the lower value of the reduction of electric energy cost is. Practical implications. An algorithm of automatic control of a dewatering plant at a mining enterprise involving the criterion that combines the rate of water level increment and electric energy cost at different day parts has been improved. The simulation modeling has made it possible to study and confirm the following: the developed algorithm of control at the expense of switching-on of a movable pump before the “peak load hours” zones aimed at entering the zones with minimal water volume level in a water inlet facility while calculating the costs of electric energy consumed by the pumps in terms of seasonal tariffs helps reduce the consumed energy costs by 10%, if water inflow is less than the one-pump output, and by 5%, if water inflow is more than the one-pump output.