maintenance and observation of the running process, CCC
identified a problemwith a throttle valve setting. The ‘low clamp’
(also referred to as the minimum level of allowed valve opening)
was much higher than required. This was due to the fact that the
original setting was based on plant conditions that no longer
existed. The low clamp setting led to excessive recycling in order
to reduce discharge pressure. After calculating and reconfiguring
the appropriate value for the low clamp, recycling was greatly
reduced. The customer achieved significant energy savings and
was surprised that a routine re-tuning resulted in an increased
efficiency of the process.
This is another case where the systemworked as designed. It
provided timely response and did what it was asked to do
flawlessly. Without application knowledge, the plant missed the
opportunity to adapt set points when process conditions
changed. Unfortunately, the static set points resulted in
considerable cost until the issue was successfully rectified.
Utilising features
A plant experienced a series of unwanted shutdowns due to
running a critical axial compressor in choke condition for an
extended period of time. This condition caused excessive blade
stress and eventually led to a major machine failure, with a very
significant lost production cost impact, even without accounting
for the large compressor repair bill. The plant performed a root
cause analysis with CCC’s support. After accurately identifying
the actual choke line for the compressor control system, the unit
was able to return to safe operation. Tremendous expense would
have been prevented had the value of the simple feature, a choke
line alarm, been understood and utilised.
Collaboration
A plant operator contacted CCC requesting assistance
in troubleshooting operational and control issues in a
remote location. The compressors were shipped with OEM
standard controls. For the first eight months after the original
commissioning date, the OEM and end user engineers had little
to no success in starting up the compressor. As the platform
was failing to produce tens of thousands of condensate per day,
losses were beginning to stack up into the tens of millions of
dollars, with no end in sight.
Upon review, it was discovered that the problems affecting
the platformwere mainly due to lack of controls flexibility. They
could have been avoided with better collaboration between the
OEM, control system vendor and end user in the early design
stages. The review of the piping layout resulted in the addition of
suction throttle valves and modifications to the controls
algorithms that enabled the plant’s successful start-up. Lost
production could have been avoided with better design
oversight.
Conclusion
Keeping technology up to date is in a plant’s best interest;
however, technology alone cannot effectively control critical
machinery without the right application knowledge and process
know-how. Combining the right expertise and the latest
technology will help owners/operators achieve their safety goals
and production targets.
Reference
1. For a more detailed explanation, visit
WHERE THE WORLD’S LNG LEADERS MEET
PRODUCED BY
Celebrating
15
Years
�
DISTINGUISHED SPEAKERS INCLUDE:
Sunao Nakamur
Executive Officer, Vice President
Fuel & Power Company
Tokyo Electric Power
Company, Inc.
Ryo Minami
Director for Oil & Gas
Ministry of Economy,
Trade & Industry (METI)
Philippe Sauquet
President Gas & Power
Total
Sukjoo Kim
Vice President &
Head of LNG Procurement
KOGAS
Yenni Andayan
SVP Gas & Power - Gas
Directorate
PT Pertamina (Persero)
Meg Gentle
President
Cheniere Marketing
Visit
to view the World LNG Summit sponsors
at InterContinental Paris - Le Grand Hotel
To secure your participation, contact
Tyler Forbes
on
+44 20 7978 0061
or email
