Identification and control of blast furnace gas top pressure recovery turbine unit

Abstract

Blast Furnace (BF) Gas Top pressure Recovery Turbine (TRT) unit is the most popular energy-saving equipment in iron making process. It is desired to control top pressure of BF precisely and reliably after installing TRT. The dynamic mathematical model of top pressure with TRT is the key point of controller design. However, it is difficult to establish the dynamic mathematical model of TRT from first principles. In this paper, the dynamic mathematical model of No. 1 TRT in Hangzhou Iron & Steel Group Company is first estimated by subspace identification method. For safety reasons, we adopt closed-loop identification method. Then a model predictive controller is proposed based on the identified model. Results show that the identified model can capture the dynamic properties of top pressure process accurately. Moreover, the model predictive controller gives excellent performance. © 2012 ISIJ.