Abstract:

 Taking the ethylene cracking furnaces in the 1500 kt/a ethylene plant at Hengli Petrochemical (Dalian) Chemical Co., LTD. as the example, this paper introduces in detail the process flow of the ethylene cracking furnaces, analyzes the problems in the conventional control scheme and re-designs the control system which includes the average COT temperature control, the branch temperature balance control, the branch temperature "high control" and "low control" and the total feed flow control. The implementation of advanced process control system, such as the hardware and software platform of advanced process control system, the switching logic between advanced control and conventional control and the operation interface of advanced process control system, is introduced. The application of this system improves the control stability of cracking furnace, prolongs the operation cycle of cracking furnace and brings remarkable economic benefits.

Key words: ethylene cracking furnace')">

ethylene cracking furnace, advanced process control/APC, temperature control