H2 ICE Competences
IAA Transportation 2022

MAHLE H2 ICE Competences

H2 ICE System Approach
Power Cell Unit& Valve TrainComponents

Test Cell
Test bench for Heavy
Duty H2-ICE engines
In-house testing to apply
MAHLE expertise for
optimization in system
environment

PistonValve setSystemApproach
Liner

Piston rings

Bearings

Possibility for joint
development withindustry partners

Holistic investigationof H2 ICE with partners
Rig tests

Crank Case
Ventilation

Engine testing onbench
Demonstrator vehicles

MAHLE provides Power Cell Unit, Valve Train and Crank Case
ventilation components embedded in a strong system approach
High Pressure Impactor
2|

MAHLE components

3|04

MAHLE H2 ICE Competences

Light Duty Vehicle H2 ICE activities
MAHLE competences

Benefits▪ MAHLE competences applied to dedicated PCU, valve train
components and crank case ventilation for DI H2-ICE− Engine demonstrator (I4, 2.0l)− Engine for a PHEV vehicle demonstrator (I3, 1.0l)▪ Material and coating solutions based on MAHLE’s experience withgas engines (CNG and H2 enginecomponents)▪ 500 h endurance testing▪ Piston / valve temperature measurement carried out− Piston temperatures slightly lower than in gasoline operation− Intake and exhaust valve below thermal limit▪ Realization of an “Zero CO 2engine concept” by enabling
conventional engine components for Hydrogen combustion▪ Short lead time (approx. 2 years) until SOPOutlook▪ Project started to investigate material and tribology fundamentals

MAHLE H2 ICE system knowhow will support to decarbonize cost sensitive (TCO approach),high range and high payload LDV applications
4|

MAHLE H2 ICE Competences

Heavy Duty Vehicle H2 ICE activitiesMAHLE competences

Benefits▪ MAHLE competences applied to dedicated PCU, valve train
components and crank case ventilation for PFI / DI H2-ICE− ~13l H2-PCU developed− MAHLE internal combustion process investigations▪ Material and coating solutions based on MAHLE’s experience withgas engines (CNG and H2 enginecomponents)

H2 aluminum▪ Short lead time (approx. 3 years) until SOP
compression height: 80 mm

compression height: 75 mm

Diesel steel▪ Realization of an “Zero CO 2engine concept” by enabling conventional
engine components for Hydrogen combustion

MAHLE dedicated H2 HD aluminum piston (l) & comparison to diesel steel baseline (r)Outlook▪ Further projects started / planned to− investigate material and tribology fundamentals− measure piston temperatures, oil and particle emissions− test PCU variants− investigate NVH and cavitation behaviour

MAHLE H2 ICE system knowhow will support to decarbonize multiple high-load HD applications
5|

MAHLE H2 ICE Competences

MAHLE solutions and competences for PCU & valve setValve set:
▪ H2 compatible materials
Hydrogenembrittlement▪ Material combination for "dry"operation conditions

Combustion
anomalies▪ Corrosion resistant materials
against condensation

Ring package:▪ Coating against wear
caused by oil dilution▪ Blow-by reduction▪ Reduction of LOC1 &related emissions

Piston:▪ Optimized ring belt area
for reduced LOC1 & Bby2
Tribology

Corrosion

Liner:▪ Optimized shape & honing▪ No use of anti-polishing ring
1 LOC: Lube Oil ConsumptionI

2 Bby: Blow-byI▪ Low piston temperature
to reduce combustion
anomalies (use of Al)▪ Reduced CR3 & adaptedbowl geometry

3 CR: Compression Ratio

Evolutionary development: Optimized components for zero CO2 combustion technology− Holistic optimization and robustness increase required8|

MAHLE H2 ICE Competences

Piston for H2 ICE
Current Activities▪ Piston technology with aluminum base material due to lower temperature and PCPexpected▪ Engine testing to gather further experience and foster possible pre-development activities if needed~130 mm~150 mm~ 140mm

Engine running inside
MAHLE

Engine tests being carried out
outside MAHLE

Engine test planned inside
MAHLE

Aluminium
PistonStatus9|

MAHLE H2 ICE Competences

LV Experience in Throttled Condition
MHD Experience in Slobber Conditions
Current design

LV like design▪ Modify top ring from keystone to rectangular− Temperature, CBU expected▪ Adjust the second land volume for better pressurerelease− Guarantee top ring stability!
▪ Second ring with Napier design + drilled gas port
− Better oil scraping + avoid pressure increase + avoid 2nd ring collapse▪ Increase 3rd land height andvolume− Better pressure release + minimize oil filling▪ 3 piece OCR in case of PN/LOC issues with idle, motoring and lowerloads− Better axial conformability/sealing

10 |MAHLE H2 ICE Competences

H2-ICE: Valve set specification
Valve stem sealing:▪ Gas lip design for high LOP according to high boost▪ Minimum leakage rate for „zero emission“ approach• High boost levels combined with gaseous fuels impose tribological challenges in valve stem - valve
guide system• Strongly contradictory requirements regarding lube oil supply regarding tribology and emissions

Valve guide
Intake and exhaust valve:▪ Corrosion resistant materials▪ Fully nitrided for improved wear resistance according to gaseousfuelrequirements• No liquid fuel on intake side and no combustion residues on exhaust side aggravate tribological challenges
significantly• Strong condensate formation from EGR (exhaust gas recirculation) as exhaust gas is pure H 2O

Valve seat inserts:▪ Materials with high wear resistance and good corrosionresistance

Valve seat insert

Valve

A new combination of requirements compared to established fuels regarding tribology & corrosionin front of moderate thermal loads
11 |MAHLE H2 ICE Competences

MAHLE solutions and competences for crank case ventilation system & oil
Crank case ventilation:▪ Assure subcritical H2 concentration in crank caseby active purging

Safety▪ Variable scavenging air flow @ constant crankcase pressure▪ Avoid accumulation and condensation of humidity
to prevent oil dilution
MAHLE High-pressure impactor
Oil:Robustness

Blow-by▪ Composition of dedicated H2 oils can differ
completely from diesel / gasoline oils (oildilution, less soot formation, …)▪ MAHLE plans to investigate H2 specific oils
in cooperation with oil suppliers

Evolutionary development: Optimized components for zero CO2 combustion technology− System approach to meet safety and robustness requirements
12 |MAHLE H2 ICE Competences

Crankcase Ventilation for H2 ICEChallenges▪ Unburned hydrogen within the crankcase ▪ High water content of blow-by-gases ▪ Residual oil content risk of backfire

oil dilution

balancing of oil separation efficiency and water accumulation

Technology▪ Description− Electrically driven side channel blower with pressure regulated impactor− 24 V and 12 V application− Up to 120 W @ max flow capacity 400 l/min and 60 mbar pressurecreation− Integrated electronics and pressure sensor (active OBD check)− Independent positioning of drive and oil mist separator

MAHLE High-pressure impactor▪ Benefits− Scavenging flow independent from engine operating point− High separation efficiency− Reliable and robust design

High performance in combination of scavenging and cleaning crankcase gases
13 |