DELIVERABLES REPORT D1
Results of the redesign for manufacture
FCH JU Grant Agreement number: 256856
Project acronym: NH34PWR
Project title: Ammonia based, Fuel Cell Power for Off-Grid Cell
Funding Scheme: JTI-FCH
Period covered:
from: 1st September 2010
to: 30th September 2011
Mr P Wilby
Tel: +44 1403 792010
Fax: +44 1403 792011
E-mail: pwilby@diverse-energy.com
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D1.
Results of the redesign for manufacture – complete
The work undertaken within this activity has focused mainly on the redesign work to achieve improved
performance (Africa 2). Major components that have been reviewed include the fuel cell stack and module,
the ammonia cracker and the recirculating condenser. The fuel cell stacks have been re-specified to
improve assembly and to deliver 1.2kW of power. The plumbing, piping and interconnects of the fuel cell
services (i.e. gases and liquids) now facilitate assembly by push fit with the construction of sub-assemblies
to de-skill the manufacturing process. Assembly drawings and process assembly sheets have been
constructed.
The hydrogen throughput for the cracker has been uprated to serve the increase power rating of the fuel
cell module. A laser welding process has been introduced in the construction of the cracker core and this in
turn will provide a more precisely controlled product. Engineering drawings and drawings and descriptions
of assembly for manufacture are complete.
The recirculating condenser is a bought in item and this can now operate over a wider ambient
temperature range (i.e. climate) than previously.
Further design advances have now been completed, the most notable being the palladium filter design and
the fuel stack size. Both of these components are high cost and clearly their operational efficiency needs to
be optimised. Thus, the fuel stack size has increased from 36 cells to 44 for the latest batch of
PowerCubes™. This in turn will provide increased efficiency to the end-user, the design value being 1.2kW
continuous. Similarly, the palladium filter design changes will derive increased separation between the
hydrogen fuel and the ‘waste’ nitrogen from the ammonia cracker. Initial tests have confirmed the new
design has met its design criteria of 1,200W continuous. Indeed, if higher pressure ammonia is available at
high flow rates (see task 6.1 below) the design is capable of reaching a higher power output with 1,3501,500 W continuous being within range for the design.
A key task on the design review was a full FMEA of the design. The analysis brought to light about 5
important and 28 minor design changes. Design modifications were completed to address the issues raised
and design modifications released to the assembly floor while the first PowerCubes were being assembled.
Further work was completed to improve the manufacturability for the Fuel cell module, moving from
conventional pipes, with Barbed fittings and crimped clamps to a push-fit assembly process allowing subunits to be assembled outside the module and then fitted.
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