homogeneous compression combustion ignition

1. Topic:- Homogeneous Charge
Compression Ignition (HCCI) Engines
Subject:- I.C. Engine
Submitted To, Submitted by,
Mr. Amardeep Sir Chinmay Sharma
UID:- K-10881
Sem./ Year:- 6th
/ 3rd

2. What is an HCCI Engine?
• HCCI is a form of internal
combustion in which the fuel
and air are compressed to the
point of auto ignition.
• That means no spark is required
to ignite the fuel/air mixture
• Creates the same amount of
power as a traditional engine,
but uses less fuel.
Traditional combustion
(left) uses a spark to
ignite the mixture. HCCI
(right) uses piston
compression for a more
complete ignition.

3. How Does It Work?
• A given concentration of fuel and
air will spontaneously ignite
when it reaches its auto-ignition
temperature.
• The concentration/temperature
can be controlled several ways:
– High compression ratio
– Preheating of induction gases
– Forced induction
– Retaining or reintroducing exhaust
gases
Click here for a nice animation

4. Advantages
• Can achieve up to 15% fuel
savings
• Lower peak temperature
leads to cleaner
combustion/lower emissions
• Can use gasoline, diesel, or
most alternative fuels
HCCI automobiles could
reduce greenhouse gas
emissions

5. Disadvantages
• Higher cylinder peak
pressures may damage the
engine
• Auto-ignition is difficult to
control
• HCCI Engines have a
smaller power range
Prototype HCCI car from Saturn

6. The Future of HCCI
• The future of HCCI looks
promising
• Major companies such as
GM, Mercedes-Benz, Honda,
and Volkswagen have
invested in HCCI research.
• Preliminary prototype figures
show that HCCI cars can
achieve in the area of 43
mpg

7. Works Cited
• “Homogeneous Charge Compression Ignition”
http://en.wikipedia.org/wiki/Homogeneous_Char
ge_Compression_Ignition November, 2008.
• “New HCCI Engine”
http://videos.howstuffworks.com/multivu/3284-
new-hcci-engine-video.htm November, 2008
• “GM Takes New Combustion Technology Out of
the Lab and Onto the Road”
http://www.gm.com/experience/fuel_economy/
news/2007/adv_engines/new-combustion-
technology-082707.jsp