A distributed control system for control and protection of boiler plant

A description is given of a project to replace the control, interlock and protection equipment on a boiler plant with a distributed control system to perform these functions. The project location was BP Sullom Voe in Shetland. The control system refurbishment was part of the Terminal Reinstrumentation and Advanced Control (TRAC) project. The site receives oil from the Brent and Ninian pipeline systems and provides processing, storage and tanker loading facilities. Power, steam and other site utilities are provided by an on-site power station. There is no import or export of power, steam or utilities from the site. The TRAC project was centred around using the PLC in the Honeywell TDC3000 DCS for plant wide control and monitoring functions. The boilers were similarly to use this equipment. As part of the review of the control strategy a HAZOP study was performed on the boiler and associated plant to identify any hazard which were previously not catered for and to confirm the requirements for the existing interlock and protection schemes.<>