Improved accuracy for turbine oil supply at Chinese Power Station
Rotork Process Controls LA-2490 modulating electric actuators have been installed to improve the speed adjustment on the hydraulic drive scoops that control the supply of oil to the turbines at the Qing Huan Giao Power Station in China.
The new units have replaced locally manufactured electric actuators that had limited modulating performance and lacked positional accuracy.
Operating from a 4-20mA control signal, the LA-2490 actuators are linked to the scoop tubes by external linear drives. Moving a pick up scoop into the oil chamber allows oil to be drawn up the tube and into the working chamber of a turbine. A maximum amount of oil in the chamber results in the maximum speed output.
Withdrawing the tube from the reservoir chamber allows oil to return to the reservoir, decreasing the amount in the oil chamber and reducing the speed output. The force required to push or pull the rods connected to the scoop tube can vary by a factor of 10 up to a maximum of 4.5kN (1000 lbf).
Further benefits of the LA-2490 include a small footprint that can be mounted in any position, simple push-button set-up procedure, easy fine tuning in the field and a low cost of ownership.