Fantastic fin fans

​​​​​It’s a fact that summers in Karratha are long, hot and humid.

And at the Karratha Gas Plant, our ability to cool our process directly impacts our ability to produce LNG. This production-critical cooling power is delivered by some 800 fin fans.

Cooling is achieved by forcing or fanning air over tubes which contain hot process fluids. The tubes have small fins on the outside surface to support more efficient heat exchange.

“When ambient temperatures rise in summer, we need as much cooling power as we can get because achieving 100% production relies on 100% fin fan reliability,” says Aaron Bruce, maintenance superintendent LNG.

Since 2016, significant improvement in the reliability of fin fans has been achieved, reducing summer production losses.

During the 2017/18 summer, fin fan production losses were 2.53 kilotons (kT). This is a whopping improvement from 36.42kT in the summer of 2015/16, and 18.82 kT in the summer of 2016/17. “This is a great outcome – I’ve never seen this level of summer performance from our fin fans,” says Phil Reid, vice president Australia Operations.

Across LNG Trains 1-5, located 30m above the ground, are 800 fin fans – each with six blades. That adds up to a lot of moving parts and due to exposure and wear, a bearing can fail and the fin fan will trip.

Fixing the right fans at the right time is a big job and it’s the key to the new approach. “All fans are not created equal,” Aaron notes. “Some have a bigger impact on production and knowing this allows us to prioritise our work.”

To understand this and execute a new approach, Maintenance collaborated with Operations and Engineering. From Operations, panel operators helped identify priorities, supported safe execution of works with optimised permit structures and further enabled maintenance productivity with fan grouping.

Engineering conducted failure mode analysis that confirmed the bearings were the number one cause of failure, and recommended the maintenance strategies and supported critical spares analysis.

A core team of 12 from Maintenance, including personnel from our main maintenance services contractor Monadelphous, then got to work.
During the winter months, when ambient temperatures were less extreme, an eight-week nightshift campaign executed large, complex repairs on the priority fans. This was called the summer readiness campaign.

This work is largely informed by the condition monitoring program, which is performed by a small team moving across the fin fan decks. This team inspects the fans for early signs of wear and tear to help prioritise maintenance work.

During the critical summer months, there is an agile front line fin fan response or “SWAT” team which rapidly responds to repair production critical fans and keep the cooling power at a maximum.

Ragan Stonier, general manager Maintenance, noted: “There is a growing culture of our people at KGP with an underlying determination to solve problems and continuously improvement our plant and equipment.”

The SWAT team’s impressive reduction in production losses hasn’t stopped its members from continuing to look at new ways to improve performance. “We have line of sight to our next wave of improvements,” says Aaron. “We like it when no one talks about fin fans and the impact they are having. “This summer, no one was talking about fin fans.”

Now that’s something worth talking about.

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Trunkline Q2 2018