A well-timed boost gives Wärtsilä 46 engines a midlife power up
3 min read
22 Jan 2021
3 min read
22 Jan 2021
With operators facing increasing cost pressures and tightening environmental regulations, upgrading older engines is an attractive and often necessary way of meeting the twin goals of cutting OPEX and reducing emissions. Our latest upgrade gives some key elements of the trusty Wärtsilä 46 a well-deserved makeover.
People have mid-life crises, but engines have mid-life opportunities – to get a new lease of life and emerge fitter, leaner and more powerful than when they first rolled off the production line. First introduced in the late 80s, the Wärtsilä 46 has proved to be a hugely popular medium-speed engine, particularly in the cruise and ferry sectors, favoured for its combustion performance and reliability. But technology has changed a lot over three decades.
A new performance upgrade from Wärtsilä, developed together with turbocharger manufacturer ABB Turbocharging, who manufacture the TPL turbocharger used in the Wärtsilä 46, makes it possible to cut operational costs and emissions while boosting engine performance and efficiency.
“This upgrade is a great investment in the future of the engine – one that addresses the economic and environmental issues simultaneously by reducing fuel consumption and therefore emissions,” explains Jyrki Salo, Senior Product Manager, Wärtsilä 46 engines. “Aside from the obvious advantages related to emissions reductions, there is the potential for competitive advantage too. The overcapacity in the shipping market right now means vessels that can offer an edge in terms of fuel consumption will win out,” he highlights.
The nuts and bolts
The ‘Wärtsilä 46 Performance upgrade – TPL 73-A4X + short overlap Miller timing’ replaces the performance-related parts of the engine’s turbocharger and the camshaft pieces that operate the inlet and exhaust valves. Replacing the camshaft pieces enables short overlap timing, which allows the engine to take full advantage of the increased charging pressure provided by the upgraded turbocharger unit. The upgrade typically takes five days from start to finish for each engine.
“In a cost-sensitive market anything that helps to cut down operating costs is well worth considering,” says Jari Välirinne, General Manager, Product Sales, Europe & Africa. “The upgrade also extends the maintenance interval for the turbocharger’s rotating parts from 50,000 to 75,000 (SIKO) running hours and resets the camshaft lifetime. Of course, new parts mean there’s less risk of an unexpected breakdown too, which can cut costs even further,” he continues.
A full, certified health check for your engine
As part of the upgrade Wärtsilä experts also give the Wärtsilä 46 a thorough health check-up and perform fine tuning to verify the current fuel injection timing and to make sure that the parameters that affect factors such as emissions are ticking the right boxes. Wärtsilä also applies for a new technical file for the engine with EIAPP (Engine International Air Pollution Prevention) certification from the class society.
“When designing an upgrade like this we always take the big picture into account. The significant improvements that this upgrade delivers are a result of the combination of the new turbocharger components, new camshaft pieces and adjusted valve timing,” Salo says. “It’s easy to lose sight of the fact that an engine needs far more air than fuel to operate. By looking at the overall system we have created a solution that increases the charge air pressure in the right place at the right time and makes sure the engine can take maximum advantage of this increase.”
While the improvements might seem small at first glance, when you consider the amount of fuel used every day by a large cruise ship or passenger ferry the savings can make all the difference. “After the upgrade the turbocharger efficiency can be three to four percent higher and the fuel consumption as much as 3.5 g/kWh less,” Välirinne points out.
All tests passed with flying colours
The upgrade concept was developed over a period of 18 months including ideation, simulation and hardware design and manufacturing. At the end of the process come the critical stages – testing, validation and certification. In Wärtsilä’s case this takes place at the very location where the Wärtsilä 46 engine is manufactured, Trieste in Italy, home to the company’s Validation Centre and one of the largest engine factories of its kind in Europe.
“The Validation Centre is a world-class facility that plays a very important role in developing these kinds of upgrade concepts,” explains Andrea Visintin, manager of the testing validation centre. “Thanks to the thorough testing by our team of experts here, we can fine tune the concept and stand behind the claims we are making in terms of turbocharger efficiency and reduction in fuel consumption and emissions.”
Collaboration with the various classification societies is another important part of this validation process, because they are the bodies that issue the EIAPP certification and approval for the new engine technical file. “We have enjoyed very smooth cooperation with the classification societies during this project and highly appreciate their expert input in helping us get this concept from drawing board to final product,” Visintin says.
“Verification and validation via compliance testing is becoming increasingly important to the shipping industry, especially in its pursuit of decarbonisation and emissions-reduction strategies,” explains Dr. Fabian Kock, DNV GL – Maritime Head of Section Environmental Certification. “DNV GL is playing an active role in this respect and works closely with engine manufacturers towards the common purpose of helping shipping to become smarter and greener.”
With the IMO’s ambitious targets of reducing CO2 by at least 40% by 2030 and 70% by 2050, anything that owners and operators can do now to cut their carbon footprint is a step in the right direction. “In many ways this is an easy win. You have to invest in maintenance regardless, and this upgrade – which can be timed to coincide with a planned overhaul – is a relatively simple way to gain a significant operational performance boost while simultaneously reducing an engine’s environmental footprint,” Salo concludes.