Calibration Equipment at Seabank Power Station.
Seabank Power is a recently commissioned CCGT
(Combined Cycle Gas Turbine) electricity generating plant
situated in Hallen near Bristol within site of the new impressive
Severn Bridge.
The station was built as a 'turn-key' contract by
Siemens Power Generation and runs 24 hours a day,
365 days a year barring routine maintenance outages.
Seabank Power consists of two generating modules
the second of which is in final commissioning and is
due for hand-over by the end of the year.
The first module has two single shaft gas turbines
with HRSG (heat recovery steam generators) on the
exhaust end supplying steam to the single steam turbine.
The arrangement is highly efficient as the waste gasses from the
combustion process are used to heat water to create steam for the
stream turbine. This arrangement produces approximatley 75 5MW
epending on ambient conditions. The station will become a 1200WM
site when the second modules' generation is included.
The Gas Turbines uses odourless natural gas, which is transferred
to the Main site at Hallen from the Gas Compression site at Pucklechurch
through a purpose built 27km pipeline. This provides approximately
8 hours of running on stored gas in the pipe.
Seabank Powers water cooling system uses secondary treated sewage
water which is further treated on site to a very high standard and recycled
in the system which improves efficiency and increases water purity as the
water changes state.
Due to the complexity of the process the control system is very measurement
intensive meaning that Seabank Power's Maintenance Department has a full
time job providing calibration, repair and routine servicing of these devices
around site.
Plant Measurement Equipment
Most measurements are performed by sensors and transmitters situated
around the plant. In total, there are over 4000 of these devices in use,
60% of which are monitoring pressure, 30% temperature and the remaining
10% measuring other parameters such as vibration, pH, flow etc.
The pressure transmitters, most of which are 4-2OmA devices
from a mixture of suppliers, monitor pressure of water, steam,
gases (natural gas, hydrogen, carbon dioxide) and oil
(for lubrication and cooling). Pressure ranges vary from vacuum
through to 250bar, in gauge, absolute or differential modes.
Maintenance Department
The maintenance department was designed to handle these activities,
which needed to be furnished with suitable equipment to perform calibration,
management and repair servicing.
In the process of selecting the equipment for the department several
suppliers were considered including Beamex, Druck, Fluke and
Haven Automation. The chosen supplier would need to have the
capability of supplying portable calibration instruments for on-site work,
a comprehensive test bench for the department and calibration management
software to control effectively and simply the large number of sensors and
transmitters. It was important for the equipment in all these tasks to be up
to date and supported by an experienced engineering supplier team.
After careful study and negotiation with several suppliers,
it was decided that Beamex could fulfil all the
requirements in offering a complete package with
their new MC5 portable calibrator, the comprehensive
and flexible facilities of their test benches, and the
QM6 calibration management software.
The chosen Beamex equipment is now in regular use, with the MC5
portable calibrator proving ideal for use around the plant performing
calibration and operational checks for transmitters in-situ, saving
considerable time in avoiding removal of the unit and returning to the
workshop for investigation.
Dave Avent of Seabank Power commented...
"Beamex visited our site with their demonstration
trailer, where we were able to see and discuss
their wide range of calibration equipment and software".
Dave continued... "We were one of the first to
purchase the new MC5 calibrator and it has more
than proved itself in its portable role.
At present we use the standard model with 2 bar and 20 bar internal sensors,
together with the optional external module giving us pressure calibrations up
to 160 bar. We simply download calibration management information for
particular transmitters from the QM6 software on the test bench computer
and perform all the checks we need at the transmitter point on the plant.
We hope to increase our number of MC5's in the near future.
The test bench performs many functions and is fitted with a choice of
supplies and calibration procedure equipment, including a PC loaded with
the QM6 software package. This contains a database of all the transmitters
in use containing a history of calibration information together with dating
details to initiate when calibration checks are needed to be performed.
This software is an invaluable tool in the calibration process, particularly
with logging characteristics of the large number of transmitters present
on the station.
With all of these Beamex facilities, the maintenance engineers can undertake
many activities including calibration, general service and some repair work
such as resetting of zero and span controls, through to a complete instrument
calibration.
Dave agrees that their present set-up is more than fulfilling the tasks that
they present to it and foresees extension in the future to include more
MC5 portable calibrators and making use of their second license on the
QM6 calibration software by bringing in a second PC system.
Successful Combination
A successful combination of Beamex's comprehensive calibration systems
being used by Seabank Power Station, an up to date electricity generating
plant employing the latest methods in efficiency, technology and
environmental friendly procedures.
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For more information, please contact:-
Beamex Ltd.
Tel: +44(0) 1455 821920
November 2000
