Collaboration produces breakthrough energy-saving solution for ships
Together with long-time partners MARIN and Grimaldi, Wärtsilä has succeeded in developing a device that takes another step towards lowering the energy consumption and exhaust emissions of shipping.
Modifying the rotational inflow of a ship’s propeller is one way to cut down on fuel costs, a high priority for ship operators. Fitted in front of a propeller, a pre-swirl stator is an Energy Saving Device (ESD) that helps to achieve greater propulsive efficiency by optimising the inflow.
During the EU-funded research project Green Retrofitting through Improved Propulsion (GRIP), carried out from 2011 to 2015, Wärtsilä, together with partners including the Netherlands based Maritime Research Institute MARIN, developed an ESD for ships fitted with fixed pitch propellers. This resulted in full-scale demonstrations that achieved a reduction of almost seven percent in the required power of a bulk carrier vessel.
To increase the total impact of ESDs on shipping energy consumption in additional markets, Wärtsilä went on to investigate the energy-saving potential of ESDs for ships with controllable pitch propellers.
“The LeanShips project offered a logical next step for our previous work with MARIN. In this project, we were joined by Grimaldi, one of our long-standing customers and close partners, who provided the vessel for carrying out demonstrative sea trials of the ESD,” says Michel Ebben, Product Manager for Propulsion at Wärtsilä Marine.
Completed in April 2019, the four-year LeanShips project was part of the EU’s Horizon 2020 framework programme for research and innovation. The aim of LeanShips was to demonstrate the effectiveness and reliability of technologies that offer energy savings and emission reductions on a large scale. It involved altogether around 40 partners and was divided into seven separate demo cases.
“The actual physical product may simply look like a piece of steel, but behind it is a huge amount of expertise and shared knowledge.”
More efficient, less polluting
As a result of the trials with Italian ship owner Grimaldi’s ‘Grande Portogallo’ – a 165-metre-long Pure Car & Truck Carrier with an 11 megawatt two-stroke diesel engine sailing 19 knots – fuel efficiency gains of 3.5 percent were confirmed. According to Ebben, this translates into a payback period of only 1.3 years.
“We consider this a significant breakthrough and demonstration of our capabilities to provide such a solution in collaboration with our partners. The energy-saving, and thus pollution-reducing potential of the product may even be higher than originally reported, as results from Grimaldi suggest a five percent decrease in fuel consumption,” Ebben adds.
Senior Project Manager Berend de Bot from Wärtsilä Netherlands was responsible for the LeanShips work package, a project divided into two main segments: a hydrodynamic and a mechanical part.
“This was, in effect, an entire R&D project, where we firstly had to develop a design and shape with the required energy-saving capabilities, and then fix it to an existing installation so that it, for example, would remain secure and not break off in extreme weather conditions,” de Bot explains.
The work included model testing at an early stage, both to find a working design and to determine the strength and load resistance of the device in various speeds and motions of the vessel. Several production and testing locations and experts in various fields, such as welding, were utilised to make sure that the product would last for the lifetime of a vessel.
“In the end, the most significant achievement of the project was that we were able to validate the potential of the solution with a demonstrative case – a full-size working example on Grimaldi’s vessel,” de Bot points out.
In Ebben’s view, the way the project succeeded in bringing together a wide range of know-how, both from within Wärtsilä and between partners, is noteworthy.
“The actual physical product may simply look like a piece of steel, but behind it is a huge amount of expertise and shared knowledge. The end result is a good example of creating substantial customer benefits by enabling both cost savings and better environmental performance,” says Ebben.
“The end result is a good example of creating substantial customer benefits by enabling both cost savings and better environmental performance.”