With the growing emission from the conventional internal combustion engines leading to global warming, a need for a cleaner emission from IC engines is required. HCCI engines offers the best of both world - emissions of gasoline engines and efficiency of a diesel engine.

1. GUIDED BY
PROF. RANGU P
The Oxford College of Engineering
Presented by
VOLLIN BRAGANZA
1OX13ME116
Technical
seminar on

2. HOMOGENEOUS CHARGE COMPRESSION
IGNITION ENGINES
(HCCI)

3. WHAT IS
HCCI ?
• HCCI is a low temperature, chemically
controlled combustion process.
• No spark plug or fuel injectors required to
ignite the fuel/air mixture.
• Creates the same amount of power output
as conventional engines, but uses less fuel
and less emission.

4. WHY HCCI ?
• High efficiency and ultra low emission w.r.t conventional
diesel engines.
• To achieve near zero Nox emission to achieve meet norms.
• To reduce fuel consumption, greenhouse gas emission.

5. WORKING
PRINCIPLE
• A given concentration of fuel and air
mixture will spontaneously ignite when
it reaches it auto ignition temperature.
• Combustion takes place when the
homogeneous fuel mixture has reached
its chemical activation energy and its
purely due to chemical kinetics.
• No spark plugs or fuel injectors used.

6. Illustration of the flame propagation in SI and
HCCI engines.

7. COMPARISON OF SI, CI AND HCCI ENGINES

8. CHALLENG
ES FACED
Control of
spontaneous
ignition
process.
01
High peak
pressure and
high heat
releases.
02
High CO
and HC
emissions.
03
Limited
operating
range.
04

9. CONTROL
MEASURES
•Variable compression ratio.
•Variable Valve actuation.
•Variable induction temperature.
•Exhaust gas re-circulation.
•Dual mode transition.

10. HCCI PROTOTYPES
• General Motors has demonstrated Opel Vectra and Saturn Aura with modified HCCI
engines.
• Mercedes-Benz has developed a prototype engine called Dies Otto, with controlled
auto-ignition. It was displayed in its F 700 concept car at the 2007 Frankfurt auto
show.
• Volkswagen are developing two types of engines for HCCI combustion. The first
called “Combined Combustion System” and the second called “Gasoline
Compression Ignition”.

11. CONCLUSION
• In HCCI engines, combustion process is an interesting option to
the conventional SI and CI processes.
• HCCI has the potential to match or exceed the efficiency of diesel
engines without the major challenge of Nox and PM emission
control or a major impact on fuel-refining ability.
• Achieving 15% better fuel economy than SI engines, HCCI engines
are definitely the future of IC engines.