Nonlinear control of vaporized cooling level

In the converter steelmaking vaporized cooling process, the serious ldquofalse water levelrdquo phenomenon appears at the drum water level of waste heat recovery boiler as the gas is burnt completely. According to the energy conversation law, a steam flow feed-forward compensator is designed as the open-loop controller to improve the previous control system. It is used to overcome the great nonlinearity of drum water level. Comparing the simulation results of three element control system and open-loop feed-forward compensation control system, it shows that the drum ldquofalse water levelrdquo phenomenon can be restrained by the new control system. The safety problem caused by low water level is improved by this design. It ensures the process stability. This design was successfully applied at Hangzhou steel Ltd.