|The Ross Barlow hydrogen hybrid canal boat is the outcome of the Protium Project at the University of Birmingham. Click to enlarge.|
Engineers at the University of Birmingham (UK) have developed a zero-emission hydrogen hybrid canal boat. The boat, called The Ross Barlow, is fully operational and demonstrates how a combination of magnet and fuel cell technologies could be used to power inland waterways craft.
The Ross Barlow was created by converting a standard maintenance boat which was donated to the University’s Protium Project by British Waterways. Engineers replaced the diesel engine with a NdFeB permanent magnet electric motor, lead-acid battery stack, metal hydride store, and 5 kW PEM fuel cell.
|Schematic for the propulsion system. Click to enlarge.|
The motor is designed by the Lynch motor company, and is based on a brushed 4-quadrant axial flux motor, with a power output of 10 kW (13 hp) with a maximum efficiency of 89%. The NdFeB sintered magnets for the motor were manufactured by the Hydrogen Decrepitation process (HD process).
Hydrogen can play a role in the processing of NdFeB magnets by either the hydrogen decrepitation process (HD) or by the hydrogenation, disproportionation, desorption and recombination (HDDR) process to produce high energy magnets.
|The HD process.|
In the HD process, an as-cast ingot is exposed to hydrogen, which is absorbed at the surface. The hydrogen enters the material in the spaces between the atoms and causes the material to expand. The differential expansion generates stress in the ingot and the alloy breaks down into a fine powder. The HD powder is then broken up further by a jet milling stage which reduces the particle size to around 5mm.
When the powder has been broken down to so fine a size, each particle of powder is a single crystal, which can be aligned in a magnetic field. This alignment is held in place by pressing the powder into a green compact, which is about 60% dense. The compact is then heated in vacuum to ~1,060ºC for 1 hour. During the heating stage the hydrogen comes out of the material and is pumped away. When held at ~1,060ºC for 1 hour sintering occurs and the compact densifies, with the assistance of a liquid formed by the melting of the Nd-rich phase. After sintering the magnets are quenched and then heat treated in order to achieve the optimum magnetic properties.
Another important on-board application for NdFeB magnets is in the guidance system where the conventional tiller can be replaced by a permanent magnet actuator.
The hydrogen is stored on board in a 5-cylinder, 130 kg Ti-V-Mn-Fe metal hydride storage system which was developed by the Birmingham group with Swiss collaborators at EMPA Laboratories in Zurich. The system yields about 2.5 kg of hydrogen. Operating pressure is less than 10 bar and the 5 units together store the equivalent of 4 fully charged standard gas cylinders at a pressure of 200 bars. To the knowledge of the team, this is by far the largest solid state hydrogen store being employed in any transport application within the UK.
The hydrogen is provided by Beacon Energy Ltd based in Loughborough, Leicestershire, and is produced by electrolysis powered by electricity from wind turbines (“green” hydrogen).
It is widely recognized that the world has no more than twenty years to meet the urgent challenges of climate change and oil depletion. Much can be gained from the operation of hydrogen-based demonstrators and the canal boat project represents one step in the journey towards a hydrogen society.
Studies on the performance of the boat will establish the viability of hydrogen for energy storage and as a fuel. We wanted to improve the science and engineering in this field by creating a real working example of this type of transport application and to enhance the public’s understanding and acceptance of hydrogen.
One of the most energy efficient means of moving goods is by canal and the threats of global warming and oil depletion are resulting in a resurgence of interest in this means of transportation.—Professor Rex Harris, project leader
Longer terms aims of the project include the development of a canal-side hydrogen refuelling infrastructure and to generate green hydrogen on suitable sites throughout the canal network. The boat will also be used as an educational tool. It features an LCD screen which displays information about sustainable technologies involving hydrogen and magnets and how these new technologies come together on the boat.
Ross Barlow was a postgraduate student who worked on the Hydrogen Hybrid Canal Boat project in its early stages and was an enthusiastic supporter of sustainable energy. Ross also helped out with many community projects in the Birmingham area. He was killed in a hang gliding accident in March 2005 at the age of 25. With strong support from his family, the project team decided to name the boat after him as a tribute.