Measuring microns to produce megawatts.
When engineers at British Energy's Heysham 1
Power Station in Lancashire were given the task
of designing a new measurement system for a
boiler they knew that the job would not be easy.
Faced with finding a reliable and accurate method of recording
microscopic variations in the displacement of the outer concrete
shell of the boiler, they first enlisted the assistance of the
Department of Civil Engineering at the University of Strathclyde
to advise on the most appropriate state of the art technologies
and components available.
Exhaustive evaluation to find the right solution
After a comprehensive analysis of the issues involved, they were
presented with a choice of technologies including contact
displacement measurement where RDP Electronics was one
of a number of potential suppliers of LVDTs with products to
meet the specification. As Wyn Roberts, Reactor Systems
Engineer for British Energy at Heysham 1 explained, "We took
the university's recommendations and ran a series of trials
based on a selection of products they had identified."
"Our aim was to measure and record
variations in displacement of only about
100 microns across the concrete surface
while compensating for variations in
ambient temperature."
Engineering the best method for mounting RDP transducers
University engineers worked with Wyn and his team to develop
special supporting brackets needed to minimise the effects of
fluctuating temperatures. Expansion and contraction of the
mounting surface could easily swamp the accuracy of delicate
measurements. A solution was found using Invar 36 - a nickel/iron
alloy with very low thermal expansion - on which the LVDT
transducers were mounted.
Then came the choice of transducer, and after further trials the RDP
solution was chosen, combining GTX in displacement of only about
gauging probes and a Modular 600 conditioning interface unit
linked to an external data recorder. "We chose the RDP solution
on the basis of its performance, accuracy and reliability; it also
proved to be a suitable, practical solution for this application,"
said Wyn.
Heysham 1 supplies the National Grid using two AGRs (advanced
gas-cooled reactors) consisting of eight boilers per reactor,
and two 660MW generators producing up to 1250MW of power.
The first of the new measurement systems was commissioned in
August 2001. Wyn concluded, "We have been very pleased with
the results and are planning to replicate the measuring system for
the second reactor in May."
Further information about Heysham 1 power station is available
from www.british-energy.com
_________________________________________________________
For sales and technical information contact:-
RDP Electronics Limited
Grove Street, Heath Town, Wolverhampton WV10 0PY. UK.
Tel: +44(0) 1902 457512. Fax: +44(0) 1902 452000
E-mail: sales@rdpelectronics.com
Website: www.rdpelectronics.com
August 2005
