March 2009 - Issue #5
Laser metal repair ready for world power
Story by Karin Derkley
View articles in related topics: Energy, Industry Collaboration
Whirring away at AGL Energy’s Torrens Island power station are several huge turbines that supply peak-period electricity to Adelaide. Each steam-driven turbine unit is as big as a shipping container and comprises hundreds of tightly fitted blades. When even one has to be replaced it is a hugely expensive exercise.
In 2005 this was the prospect facing AGL’s turbine management team. The leading edges of some of the stainless steel blade units were eroding – victims of condensing steam. Replacing each metre-long blade – there are hundreds – would cost several thousand dollars, plus 10 weeks in lost production time.
Low-pressure turbine blade erosion caused by condensing or wet steam is a problem facing many power stations operating similar turbines around the world. At forums run by the federally funded Cooperative Research Centre (CRC) for Welded Structures under the leadership of Dr Colin Chipperfield, this problem was identified in 2000 as the number-one maintenance issue facing the electricity industry. It was so pressing a problem that 11 members of the group, including AGL, agreed to fund the research needed to find ways of solving the problem other than replacing the blades with new ones, or removing them from the rotor and repairing off-site.
“You’re working on an operational turbine and there are significant implications if something goes wrong. You really need a champion within the industry like AGL to support new technology while you are refining it.”
Professor Milan Brandt
The research team, involving CSIRO and Swinburne University of Technology’s Professor Milan Brandt, believed it had an answer. Professor Brandt, an expert in laser technology, had been conducting research for some years on the use of laser technology to repair steel surfaces. The advantage of using laser surfacing technology is that it is able to deposit a wear-resistant coating on the blade surface without distorting the metal, thus retaining the blade material’s mechanical properties. The new method uses high-power laser energy to fuse a metal alloy powder to the turbine blade’s surface. The laser supplies a high-energy stream into which a metal alloy powder is directed, fusing the metal to the blade’s surface.
Tests by Professor Brandt and his team at Swinburne’s Industrial Research Institute proved that the laser resurfacing technology worked well in a laboratory setting, but the laser equipment was too large to dismantle and ship to the power station. The breakthrough came when Professor Brandt was able to buy a portable diode laser unit in 2003, with the help of an Australian Research Council grant. The transportable unit meant laser-resurfacing technology could be applied at a power station using a robotic arm. After extensive laboratory experiments all that was needed was a company prepared to run a field trial.
AGL’s asset manager for turbines Kym Wickstein says he was impressed by the potential of the technology. He was also aware that working with Professor Brandt’s Swinburne team offered a unique opportunity to help shape the new technology to the company’s particular needs. He recognised that working with a public university offered a rare opportunity to have input into how a technology was to be developed. “It might have been a different experience had we been dealing with a single private entity, but this gave us the opportunity to tap extensive research and development work,” he says.
In 2004 Professor Brandt’s team was asked to repair seven of the most eroded blades using the laser resurfacing technology. When, a year later, the resurfacing was holding up, the team resurfaced another 15 blades.
Around this time, the CRC for Welded Structures that initiated and funded the laser-resurfacing project was wound up (CRC centres have a statutory seven-year life), which meant that while Swinburne was still the mainstay for the research work, the project would need to be ‘spun-off’ into a commercial project.
Robert Small, a metallurgist with engineering consultancy Connell Wagner, was involved with one of the 11 sponsor groups (Pacific Power) when Professor Brandt was first trialling his laser resurfacing technology with AGL. He agreed to come on board, together with the CRC’s Dr Chipperfield, to help establish a new entity – Hardwear Pty Ltd – to commercialise the process. “The project was already developed enough by that stage to ‘hatch it off’, but it needed a lot more development in the real-world engineering area,” Mr Small says.
What was needed was an investor prepared to extend the money to take it to this next stage. Swinburne had already agreed to be a shareholder in Hardwear and Dr Chipperfield, Mr Small and Professor Brandt were able to convince Cleantech Ventures, which manages the Centre for Energy and Greenhouse Technologies, to become a venture-capital partner. Having Cleantech on board was enormously helpful in getting the technology into the industrial marketplace, Mr Small says: “They were able to give us valuable guidance as to how to commercialise the business.”
In 2007, with the support of Cleantech as well as Swinburne, Hardwear carried out its biggest job to date, again with AGL, resurfacing an entire set of last row blades on one of its 200-megawatt turbines – 180 blades in all. Early in 2008 another set of blades was resurfaced using Professor Brandt’s laser-resurfacing technology.
Having AGL as its first real customer has boosted the start-up company financially and is leading the way for other power station operators to adopt the laser-resurfacing technology, says Bruce Whan, director of Swinburne’s commercialisation arm, Swinburne Knowledge. Mr Whan is also Hardwear’s commercial manager.
Professor Brandt says that without AGL the commercialisation simply would not have got off the ground: “You’re working on an operational turbine and there are significant implications if something goes wrong. You really need a champion within the industry like AGL to support new technology while you are refining it.”
For AGL, the new technology has meant a saving of millions of dollars and added 15 to 20 years to the life of the plant. But, says Mr Wickstein, it has also demonstrated the benefit of the three-way partnership between the university-supported research team, the industry group and a customer prepared to step forward and try something new.
With Professor Brandt, Mr Whan and Mr Small working so closely with the power station industry, winning the interest of power station operators has been a result of strong networking as well as successful demonstrations of the technology’s effectiveness.
To John Beynon, Dean of the Faculty of Engineering and Industrial Sciences and executive chairman of Hardwear, the success of Hardwear shows the importance of the team approach in commercialising an invention. “It’s not an easy thing to turn an invention into a successful business. But Milan [Professor Brandt] understood that he needed the help of others with the commercial nous to get the business up and running.”
The challenge now is to take Hardwear to the next step, to spin it off from what Mr Small describes as the Swinburne “mothership”.
“I think Swinburne has benefited enormously from being associated with Hardwear. But I don’t think the university sees itself as a long-term owner of a turbine repair company, so there will be a point where it needs to become an independent business.”
Taking the technology overseas will be essential to its long-term commercial future, Mr Whan says. “Blade erosion is a problem that only emerges in a power plant once every 10 to 15 years, so you really need to be conducting this kind of business globally to make it work.”
Mr Small says the company is intending to appoint a consultant to look at ways of broadening the market for Hardwear’s laser-resurfacing technology. Laser resurfacing is suitable for any fixed machinery with metal surfaces that wear out. “We’ve established a long-term relationship with AGL as a customer, and in this process we’ve been so busy that we haven’t been able to look at other areas.” Hardwear is seeking to establish commercial partnerships and welcomes enquiries from interested parties.
When the company is finally spun off from Swinburne, it is not only the financial return that the university will benefit from, Professor Beynon says. Seeing research applied so profitably to industry also demonstrates the relevance of the university’s research program to the real world. “It is part of the university’s mission to make sure research is not just about producing a journal article,” he says. “But to see it turned into practice and making a difference.”
