Page 180 - Offshore Electrical Engineering Manual

Process Shutdown System 167

devices deliver predictive alerts, millisecond data capture, validated data, field-based
control, diagnostics, and asset information bi-directionally with the DeltaV system.
DeltaV Ff I/O communicates digitally with field devices, increases your input/output
capacity, and provides access to more information about your process than conventional
I/O subsystems. DeltaV Ff I/O enhances device diagnostics that affect the control strat-
egy and alert operators to device malfunctions’ (Emerson Process Management DeltaV
system overview). These instruments have the ability to self-diagnose faults and report
back to the control system the nature of the fault and the time of occurrence. The facil-
ity to time-stamp in real time at the instant an alarm level being reached is invaluable in
tracing the cause of any process upset and is a basic requirement of an effective alarm
management system. Alarm management systems are necessary to prevent operator
information overload and assist in the detection of the cause of the alarm event to
ensure safe and speedy rectification of the problem. The ability to store real-time pro-
cess information and display in detail the chronological sequence of events leading up
to an alarm after the event is also helpful in analysing the root cause of the problem.
Information on plant status can also be made available at a remote location such as
the shore support base, engineering centre or company management offices. Details
such as real-time process operations, historical data, and operational efficiency can
be made available to the relevant departments to assist with problem solving, main-
tenance planning and resource availability without having to visit the installation.
This reduces the number of personnel required on the installation, thus increasing
safety by reducing the risk to personnel and reduces the time taken to identify and
rectify problems, further reducing risk and maximising the availability of the plant.
‘Honeywell’s Experion ® Process Knowledge System (PKS) with unique distributed
system architecture and digital video management enables real-time remote monitor-
ing, maintenance and operation of offshore facilities from a centralized onshore con-
trol centre. With this solution, you can leverage expertise across remote sites, make
faster and more effective decisions, and achieve greater productivity. Additionally,
you can reduce helicopter flights, ship movements and supply of material to your off-
shore platform, and above all, improve safety in hazardous environments by remov-
ing personnel from remote locations’ (Honeywell Offshore Oil and Gas Solutions).
These sophisticated process control systems are available from several sources; those
that are most commonly found in North Sea oil and gas installations are ABB’s Advanced
Process Control System, Emerson Process Management’s DeltaV Digital Automation
System and Honeywell’s Experion Process Knowledge System. All systems offer similar
performance and expansion capabilities; all systems can also offer an integrated process
shutdown capability with fire and gas detection as part of the package.

PROCESS SHUTDOWN SYSTEM
This by definition is a safety-related system, as it is there to shut down the process when
predetermined conditions occur that risk a loss of containment. As a safety-related sys-
tem, it should be designed, operated and maintained in accordance with IEC 61508,