World's Largest Tonnage Range-Extended Rotary Drilling Rig Rolls Off Production Line in Changsha, Hunan

The world's largest tonnage range-extended rotary drilling rig has been launched in Changsha, Hunan. This drilling rig has an operating weight of 200 tons, a torque of 620,000 Newton-meters (Nm), and a hole diameter of 3,500 millimeters. It has achieved key core technology breakthroughs in multi-motor synchronization, transient large load buffering control, and main hoist potential energy recovery, among other areas. The rig has obtained over ten related authorized patents and has achieved high-precision synchronization of multi-motor speed and torque with a dual closed-loop system. The lifespan of the drill pipes and tools has been extended by 20%, impact and vibration have been reduced by 15%, and the energy recovery rate reaches over 70%. Each descent can recover up to 5 kWh of electricity, which is used for cabin heating and auxiliary battery heating in low-temperature environments, leading to an overall energy saving of 5%-10%. (CCTV News)