Truck & Off-Highway Engineering - October 2022 - 6

TECHNICAL INNOVATIONS
" We got a head start
on the industry from a
testing perspective;
we'll be able to capitalize
on those gains with this
hydrogen capability. "
- David Proctor, Allison VE+ET
general manager
exhaust-scavenge system clears the
dyno cell air " very quickly " when a trace
of gas is detected, Szilveszter said.
" It's been a little more than what we
anticipated when we planned to add
the hydrogen test component to the
facility, but it's essential for a safe test
environment, " Proctor said.
H2-fueled ICE testing
Allison's Tim Szilveszter (at left) and David Proctor with some of the Vehicle Electrification
+ Environmental Test Center's hydrogen-test safety equipment.
The second cell, configured for the
most powerful vehicles, has two 72-in.
rolls, capable of handling 900 kW and
1180 kW. The dynos are calibrated to
regenerate electric power back into the
grid, and their rollers can be moved 330
in. (8382 mm) longitudinally in their
subfloor saddles to accommodate long
wheelbases such as found on hydrogen
and EV buses.
" We can test from Class 3 delivery
vans to very heavy vehicles, " Szilveszter
noted, in a temperature range from -54
to +125 deg. F (-48 to +52 deg. C), with
full simulation of altitudes up to 18,000
ft (5,486 m) and replicating duty cycles
necessary for regulatory compliance.
The largest chunk of investment for
the VE+ET's hydrogen/CNG testing was
aimed at ensuring that safety is para6
October 2022
mount in all testing related to the gaseous
fuels. During SAE Media's tour,
Proctor detailed the integrated technologies
that virtually wallpaper the
dyno cells, as well as those related to
the in-plant fueling system. " We've implemented
hydrogen-gas detection in
case of leak in our chassis test cell, including
thermal imaging cameras.
Hydrogen burns invisibly, " he explained.
" If you had a leak and it ignites, you
may not know it. "
The camera array covers the entire
vehicle as it sits in the dyno cell. The
camera inputs are sent to a sophisticated
monitoring system that will trigger an
alarm when a leak is detected. The system's
sensing capabilities also detect
methane, in the case of a leak during
CNG-fueled engine testing. A 2,500-CFM
Allison Transmission also is interested in
testing hydrogen-fueled combustion
engines, based on discussions with
OEM customers. " We're looking into
whether our emissions equipment can
support hydrogen-ICE testing, " Proctor
said. " The flow rates of a fuel cell and
ICE are different. Unlike in a fuel cell,
burning hydrogen in an ICE creates a
byproduct. We're learning more about
the consumption of hydrogen; we might
have to expand our system to add an
accumulating tank for constant flow, to
keep up with the demand. But we're
open to testing anything that's got a
hydrogen system on a chassis. "
According to Szilveszter, there is a
growing list of OEMs seeking HFCV
testing with Allison's full environmental
capabilities. " We've prepared our
capabilities to be ready for the needs
of alternate-fuel testing and upcoming
emission standards.
" While the regulatory community is
still in the process of determining what
the industry's needs are and the technical
reality [for future rulemaking] is, "
he noted, " with this new facility Allison
is well positioned to meet the needs of
alternate-fuel development at the
chassis level. "
Lindsay Brooke
TRUCK & OFF-HIGHWAY ENGINEERING
LINDSAY BROOKE

Truck & Off-Highway Engineering - October 2022

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