Energies, Vol. 12, Pages 606: Analysis of the Peak Load Leveling Mode of a Hybrid Power System with Flywheel Energy Storage in Oil Drilling Rig (Energies)

The load frequently oscillates in large amplitude like pulses when the draw-works lift or lower in the oil well drilling rig, and that makes the diesel engine run uneconomically. A new solution for the pulse load problem is to add a motor/generator set and a flywheel energy storage (FES) unit to the diesel engine mechanical drive system to form a hybrid power system with energy storage. The storage capacity of the power and energy, and the charging-discharging operation modes are discussed for the first time. The engine power output in frequent fluctuation was measured in the oil well drilling engineering practice. The configuration and the theoretical model of the hybrid power system with energy storage and peak load leveling were established. Furthermore, 1% to 12% saving of fuel is possible for the case of single engine in the load leveling running mode compared to bi-engines in a traditional running mode for the peak load between 900 to 1200 kW and the valley load between 200 to 600 kW. The experimental verification of the load leveling with FES confirmed that the diesel engine worked more smoothly with less smoke emission. In addition, 5% to 10% more fuel was consumed in the load leveling test compared to the traditional running mode with the drive-by 800 kW diesel engine. However, 21% fuel saving was obtained in the load leveling test with the drive-by 400 kW diesel generator.