MEASUREMENT & MONITORING
MONITORING HOT SPOTS
ADVANCED ENERGY - LUMASENSE
CVM SYSTEM FROM LUMASENSE ALLOWS OPERATORS
TO MONITOR THE TEMPERATURE AND INTEGRITY OF
CRITICAL ASSETS SAFELY AND ACCURATELY
In petrochemical and refining facilities, the
monitoring of critical assets such as reformer
furnaces and gasification vessels is crucial
to maximising efficiency and minimising
system downtime and potential safety issues.
The extreme temperatures and pressures
involved in these processes can result in high
exterior skin temperatures on these assets
and their supporting manifolds, piping and
joints. Such intense stresses can then lead to
damage and failure of the vessels.
Areas of poor combustion mean cooling can
be as much of a problem as overheating. If
temperatures are too low, condensate can
build up between the shell and refractory,
leading to corrosion and lower pressure
containment capability. Corrosion can also
cause the refractory to flake off, allowing
sudden burn-through of the shell.
With this in mind, accurate temperature
measurement is a vital part of keeping
production running. Yet these extreme
temperatures and non-uniform gradients
mean obtaining accurate data at multiple
critical points is a difficult task. Traditionally,
thermocouple systems and fibre optic
distributed sensing systems have been used
for temperature measurement on critical
vessels, but these sensors can be unreliable
and prohibitively expensive to install and
operate.
Typically, they employ wired or fibre optic
networks with point sensors which only
monitor the temperature of discrete points
on the outside of a vessel, often with
poor spatial resolution. This can result in
inaccurate measurements owing to skin
temperature gradients. In addition, the
failure of thermocouples or fibre breakage
can leave dangerous gaps in entire
monitoring systems until they are replaced
or repaired.
Instead, innovative thermal imaging systems
have demonstrated how radiometric
thermography has evolved into a mature
and cost-competitive alternative. The
non-contact nature of infrared thermal
imaging is more robust, more reliable and
easier to maintain than wired networks. It
also presents a number of technological
advantages, such as graphical visual displays,
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historical archiving and trending, hot-spot
tracking and easy integration into existing
control systems.
THE BIGGER PICTURE
Advanced Energy’s LumaSense
ThermalSpection CVM system uses micro-
bolometer-based imagers to collect thermal
infrared radiation emitted from monitored
components, giving accurate temperature
readings at up to 500°C or more.
With multiple imagers placed strategically
around the vessel perimeter, a user can build
a complete thermal image, with special
resolution down to 5cm or less – all without
direct contact. Each camera is mounted
in a sealed, ATEX- or Class I, Div 2-certified
housing. This unit includes internal cooling
and a positive pressure purge to prevent
flammable gases or dust from entering the
enclosure.
With one-second response times, the
ThermalSpection CVM system provides
continuous coverage with alarm generation
functions. Output options include OPC to the
plant DSC, Analog and relay outputs. Custom
software options build on this platform
provide displays of thermal profiles, historical
trends which can be compared against
baseline performance and developing hot
spots can be tracked in real time.
A further benefit of remote monitoring is
that the system can be installed, upgraded
and serviced in the field, with the vessels
remaining in full operation. Each client’s site
is custom-modelled, with optics and camera
mounting locations chosen to guarantee the
best spatial coverage and resolution.
www.lumasenseinc.com