The advanced process control systems for the SC-1 type ethylene cracking heaters at Lanzhou Petrochemical Company 460KTA Ethylene Plant were designed

including the average coil outlet temperature controllers

the pass outlet temperature balance controllers

the total throughout controllers. The software and hardware structure of the control systems

the switching logic between advanced control and DCS regular control

the DCS operation interface for advanced control were introduced. The control steadiness and control accuracy for cracking heaters are greatly improved by using the advanced process control systems

and remarkable economic benefit is obtained.