Feature 5 | SUBMARINE PROPULSION
Hybrid nuclear/fuel-cell submarine
proposed
At the RINA Warship 2008 conference in Bath in the UK earlier this year,
a paper was given that described a design for an innovative hybrid nuclear/
fuel-cell power plant for a submarine.
his new hybrid nuclear/fuel cell
would be capable of nuclear-
Tpowered high-speed transits and
fuel-cell-powered slow-speed operations.
As the authors of the paper, Rob
Goodenough, a technology development
officer in the Fleet Wide Engineering
IPT, UK Ministry of Defence, and
Alistair Greig, a senior lecturer in the
Department of Mechanical Engineering
at University College London (UCL)
explained, the concept also provides a fully
air-independent auxiliary power source to
increase safety in the event of unplanned
reactor shutdowns during under-ice
operations and high sea states.
The Proton Exchange Membrane fuel
cells (PEM FC) provide 477kW, suffi cient For the purposes of the study, the exact displacement was not required but was assumed
to power the 3000tonne submarine to a to be similar to a small SSN/large SSK, such as this Collins class submarine.
maximum sustainable 8knot dived speed.
Sufficient hydrogen and compressed
oxygen is carried to provide seven-days increasing complexity and innovation the lithium-ion batteries
fuel-cell operations at an average 6knots; the possible options for a fuel-cell-equipped
•
Option 2: replace the diesel generators
fuel-cell system could either be distributed SSN are as follows: with a fuel-cell system to reduce noise,
around the hull or inserted as a 5.6m plug.
•
Option 1: partially replace the battery vibrations, maintenance requirements
Th e selection of reversible fuel cells allows with a fuel-cell system to provide longer and air dependence
onboard hydrogen and oxygen regeneration duration/higher available power during
•
Option 3: design a hybrid nuclear/
whilst in nuclear mode, negating the a reactor scram (unplanned reactor fuel-cell plant for a submarine capable
requirement for separate electrolysers. shut-down for safety purposes) than of high-speed transits and quiet
As the authors of the paper pointed out, is possible with existing lead-acid or operations. Th ough of a similar system
increasing environmental concerns and
dwindling fossil fuel reserves are driving
Low-speed power-
demand for cleaner, more effi cient power 600
speed curve.
generation. As a result a number of recent
ship designs have incorporated fuel cells into
500
their power plants, either as a prime mover
) 400
or an auxiliary power generator.
W
r (k
The hybrid submarine design they
300
e
w
proposed is reliant on a number of
o
P
200
novel technologies and raises serious
safety concerns, which were addressed
100
in the paper, as were basic calculations
0
to provide an indication of weight and
024681012
volume requirements of the fuel-cell plant
Speed (knots)
and to quantify the safety risk. In order of
42 Warship Technology October 2008
WT_Oct08_p42+43+44+46+47+50+51.indd Sec1:42 10/10/08 1:17:13 PM
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