Truck & Off-Highway Engineering - April 2024 - 6

TECHNICAL INNOVATIONS
An employee monitors progress of fuel-cell electrodes in the stack
assembly room at FCSM.
From left to right, GM Executive Director Global Hydrotec and GM Defense
Charlie Freese, FCSM President Suheb Haq, FCSM Vice President Tetsuo
Suzuki and American Honda Vice President of Sustainability & Business
Development Jay Joseph at a GM-Honda announcement of the start
of production at their 50-50 joint venture production facility, Fuel Cell
System Manufacturing LLC (FCSM) in Brownstown, Michigan. FCSM is the
first large-scale manufacturing joint venture to build fuel cells.
An employee assembles a fuel-cell system in the build room at FCSM.
made up of hydro-entangled carbon-fiber filaments that
change the distribution of the water and gases flowing
through the system.
Valve and switching technologies, as well as coolant management
overall, are also critical in fuel-cell systems, and new
innovations are in demand, Freese said. The valves used in
Hydrotec " deal with a lot of water, but they're not like those in
a typical automotive coolant system. Some are bespoke for
the fuel-cell application. "
There are also fuel-cell-specific components related to system
safety, including pyro switches: " We're dealing with hydrogen
and electricity. In the event of a vehicle crash, we have to
be able to discharge all the energy safely and quickly, " Freese
asserted. " Pyro switches kind of borrow from airbags, but
they've never been used in an engine configuration before. "
Automation, simulation keys
Fuel-cell modules also offer new applications for " old tech "
such as aluminum casting, used in the stack housing and in
6 April 2024
the cradles, which resemble IC-engine cradles but are different.
" We do development with the supply base " in these areas,
Freese said. He predicts that as volume demands rise for
fuel-cell power applications, " some of the smaller specialist
suppliers will have to be brought into a higher-volume realm
- or perhaps some of the larger suppliers will step in. "
GM and Honda engineers developed new manufacturing
techniques and approaches to automation that Freese claims
enable reductions in fuel-cell cost and increased productivity.
For example, the coated membrane film arrives at the
70,000-sq.ft. Brownstown, Michigan, plant in large rolls.
Feeding off the roll at a rate of seven meters per minute, the
film is automatically scanned to detect any defects at the micron
level, Freese explained. It is then cut to length, shaped
and a gasket layer is applied. The membrane then moves into
a highly robotized stacker. In 10-second intervals, robots take
the elements and build them into the Hydrotec stacks.
The GM-Honda fuel-cell development team is co-located
with the manufacturing engineers and benefits from a dedicated
software-engineering group. " We don't share the software
group - that's a key advantage for us, " he said. While
the Hydrotec team relies on some off-the-shelf simulation and
modeling tools, much of the " sim " and modeling toolbox for
fuel cells " had to be invented. "
Freese noted that the 400,000-plus hours of testing behind
the Hydrotec production launch " is more than any ICE
program I'm aware of. "
Lindsay Brooke
TRUCK & OFF-HIGHWAY ENGINEERING
CLOCKWISE FROM TOP LEFT: GM; SANTA FABIO FOR GENERAL MOTORS; GM
Truck & Off-Highway Engineering - April 2024

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