Truck & Off-Highway Engineering - August 2023 - 20

BOSCH HIGH on HYDROGEN
Dr. Markus Heyn, chairman
of the Mobility Solutions
business sector.
" Over the long term as well,
we want more than half of the
fuel-cell powertrain by value to
be created internally. "
said Hans-Joachim Schulz, director in product management. " Our second
generation will be shorter in height - it will be flatter - and it will
have the flexibility to put the modules side by side like here [on the current
truck] or on top of each other, or to separate them even. "
The heart of the FCPM is the stack, specifically designed for comFour
hundred and fifty-five PEM fuel cells are combined to form a
stack, providing more than 100-kW net output. Two such stacks
comprise the fuel-cell power module, delivering more than 200 kW.
In the initial stages, the Stuttgart-Feuerbach site will
produce up to 5,000 modules per year at full capacity.
" In the years thereafter, hopefully we will add another
digit to that, " Heyn said. Bosch expects that China initially
will show the strongest growth potential.
The Iveco Heavy Duty FCEV for the European market
was on display at the Bosch Tech Day. With a payload
of roughly 154 pounds (70 kg) of hydrogen from
five tanks, the truck reportedly can travel up to 497
miles (800 km) without refueling. It takes about
20 minutes to refuel.
The fuel-cell power module comprises several hundred
individual parts, weighs more than 1,102 pounds
(500 kg) and has a surface area of roughly 161 square
feet (15 square meters). The current module was designed
to fit the envelope previously occupied by the
truck's combustion engine.
" The idea behind this [current system] was time to
market. This is the ideal solution for existing new trucks,
but we also are working on our next generation already, "
20 August 2023
mercial-vehicle applications. Several hundred PEM (polymer exchange
membrane) fuel cells - 455, to be exact - are combined to
form a stack, providing more than 100-kW net output (130-kW
gross). Two such stacks comprise the FCPM, thus delivering more
than 200-kW net (260-kW gross).
Peak efficiency of the stack is about 63%, according to Jan
Buechner, product manager for the fuel-cell power module. " But you
would not usually run the stack in that power area because that
would be at relatively low power output, " he explained to Truck &
Off-Highway Engineering. " Usually, this system is run at about 40%
power, if cruising on a highway - that's the sweet spot. Then you get
roughly 52% system-level efficiency. " For the next generation,
Bosch's target is to increase the efficiency by 3-5%, he said.
" Of course, in the future we see even higher power demand, "
Buechner shared. " The question is how we want to achieve higher
power output. We could increase the number of cells, increase the
size of the actual cells, we could go higher with the current and so
on. So, we are now investigating different possibilities. "
He added that Bosch already has received feedback, particularly from
the North American market, to go up to 300 kW net with a twin system.
" So, the stack would have to increase the [gross] power output to about
200 kW - it's at 130 kW now - that's the target, " Buechner said.
Smaller stack sizes also will be available for light commercial vehicle
(LCV) applications, with 275, 335 or 419 cells. Each PEM fuel cell is roughly
the size of an envelope and weighs less than 3.5 ounces (99 grams).
TRUCK & OFF-HIGHWAY ENGINEERING
FROM LEFT: SAE/RYAN GEHM; BOSCH
Truck & Off-Highway Engineering - August 2023

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