Truck & Off-Highway Engineering - February 2021 - 10

Dr. Marco Warth expressed a very positive
outlook for hydrogen fuel cell technology:
" From 2030 onward, we are going to see even
higher volumes, at least in Europe. "
commitment from the Paris Climate
Agreement to be CO2 neutral by 2050. "

Unique FC engineering

The air management within fuel cells
places extremely high demands on the

components used. To prevent damage
to the cell, harmful gases such as SO2,
O3, NOx and NH3 as well as particulates,
need to be separated reliably. For this
purpose, Mahle has developed a multilayer filter medium that Warth describes as " highly effective. " In this design, a substrate material ensures mechanical stability, a particulate filter layer removes NaCl, a molecular layer prevents NH3 from entering the fuel cell, an
activated carbon layer absorbs unwanted hydrocarbons, and an additional,
specially impregnated activated carbon
layer adsorbs SO2, H2S and NOx.
There is also the critical issue of managing humidity. " The water balance of a
polymer electrolyte fuel cell significantly affects efficiency and service life, "
Warth explained. " If the membrane
dries out, this will lead to a gas breakthrough, while surplus water has the
undesired effect of blocking the gases
to freely enter the fuel cell. Therefore,

it's not sufficient to filter the external air
supplied to the fuel cell - its humidity
must also be precisely controlled. "
For this purpose, Mahle - together
with affiliated partners and with funding from the German Federal Ministry of
Economics and Technology - has developed a flat membrane humidifier to
ensure that the supplied air is humidified reliably. In this device the exhaust
and supply air are in cross flow and
separated by the membranes. A moisture exchange takes place across the
membrane material. Deionized coolant
is used to cool the fuel cell; it is not
electrically conductive and thus will not
cause short-circuit current flow in the
fuel cell.
As a result, the components used in
the coolant circuit must be resistant to
ionized water. Mahle has developed a
special process that ensures component durability. To ensure the non-conductivity of the coolant, the company

The power behind it all.

- 17.8 kW
3C 8.8
.99L - 1.6L

- 49 kW
4L 30
2.2L
2L

- 84 kW
4J 52
3.0L

- 140 kW
4H 129
5.2L

- 210 kW
6H 130
7.8L

4HV1

Natural Gas / Propane

- 270 kW
6U 170
9.8L

- 382 kW
6W 250
15.7L

NG
78.4 HP (58.5 kW) @ 1800 RPM
79.8 HP (59.5 kW) @ 2200 RPM
4.6 L

LP
82.5 HP (61.5 kW) @ 1800 RPM
56.3 HP (41.9 kW) @ 2200 RPM
4.6 L

Technologically

MAHLE

TECHNICAL INNOVATIONS

Truck & Off-Highway Engineering - February 2021

Table of Contents for the Digital Edition of Truck & Off-Highway Engineering - February 2021