Application Of PKS Distributed Control System In DCU

The Delayed Cooking (DCU) Unit in Shandong Binhua Binyang Gas and Chemical Limited Company is characterized with complex technological process and harsh operational constraints. It consists of heating furnance and coke drum, fractionating tower, absorbing and stabilizing unit. There are many control loops in reaction with many control schemes and control loops in DCU. This raise higher demand on operators. In order to ensure the process to work normally and continuously, DCS must be used. This dissertation investigates the application of Honeywell PKS DCS in DCU. Database configuration, flowchart configuration and control configuration, etc, have been completed in this dissertation.This thesis introduces in detail the operation of PKS system and superiority of PKS's control and management network. The design and implementation of the the control and management network has also been discussed. Basing on the actual requirement of 1000 kt/a DCU, the configuration scope of PKS, function of PKS was analyzed. Then configurations of the system have been completed, including system configuration, database configuration, flowchart configuration, alarm and display configuration, trend and report configuration, etc. The thesis focuses on analysation of control scheme. Control configuration has been completed using Control Builder. Important maintenance of DCS is introduced after the DCS has been committed into action, especially maintenance of IOP.In this thesis nonlinear level control algorithm has been studied to cope with strongly coupled properities in absorbing and stabilizing unit. Comparing with PID cascade control scheme, the nonlinear level control algorithm can maintain the level between the desired high limit and low limit. Thus the flow will not fluctuate rigorously. This can bring benefit to the downstream unit.The implementation scheme baseing on OPC has been researched.Since the DCU has been put into production, the reliability of PKS DCS system has been proved. The control results reach the anticipate goal. This lays a foundation to implement the nonlinear level controlscheme.