Analysis and Improvement of the High-speed Switching Program for Booter Fans

Baosteel Power Plant Unit 4 is the first one in the world that has a BFG generator with the maximum flow rate of 1 031 km3/h.It is equipped with three dual-speed BFG booster fans.When the supplier designed the switching program for the BFG booster fans,it was to use the solenoid valve circuit to attain the stability and controllability of the BFG pressure through fast switching the valve position at the fan inlet,either half opened or fully opened.In the debugging process,it was found that there were some defects with the original switching design.The engineers of Baosight Software Company broke through the original design concept,discarded the switchover technology of the solenoid valve,adopted the two-step method of analogy command switching,successfully achieved the auto-switching of the booster fan between high speed and low speed,and the stable control of the BFG pressure.