Presentation on HCCI and CAI engines.

1. A Seminar Report
on
“HCCI AND CAI ENGINES”
by
Saurabh Y. Joshi
Submitted in partial fulfillment of the requirement for the degree of
Bachelor of Engineering (Mechanical)
Year 2016-2017
1

2. CONTENT:
 Introduction
 Basics of HCCI & CAI
 Working Principle
 CAI Gasoline Engine
 Method to Obtain CAI
 Emission With CAI & SI Engine
 Merits
 Demerits
 Future Scope
 Conclusion
 References
2

3. INTRODUCTION
 HCCI-Homogeneous Charge Compression Ignition
 For Diesel Engines
 CAI-Controlled Auto-Ignition
 For Gasoline Engines
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4. Basics of HCCI & CAI
 HCCI is a form of internal combustion in which fuel and
air are compressed to the point of auto ignition
 Spark plug is not required
 Creates same power as conventional engines but has high
efficiency
4

5. Fig.1 Difference between SI,CI & HCCI Engines
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6. Working Principle
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 4-stroke engine
1)Suction
2)Compression
3)Expansion
4)Exhaust
 Compression Stroke : A given concentration of fuel
and air will spontaneously ignite when it reaches its
auto-ignition temperature.

7. Fig 1. Working of HCCI engine
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8. CAI Gasoline Engines
 Compression ignition in gasoline engines
 Requires high compression ratio
 Used in dual mode at high load
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9. METHODS TO OBTAIN CAI
 Residual gas content or EGR
 Compression ratio
 Intake mixture temperature
 Intake mixture pressure
 Fuel-air ratio
 Coolant temperature
 Injection timing in gasoline direct injection engines
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10. EMISSIONS WITH CAI AND
SI ENGINE OPERATION
 The NOx emissions with CAI operation are extremely
low.
 HC emissions were higher as use of very lean mixtures
results in partial misfired combustion increasing HC
emissions.
 High HC & CO emission.
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11. Figure 3-Comparison of indicated specific emissions of CAI & SI engine
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12. Merits
 Extremely low NOX emissions
 High fuel efficiency & High part load efficiency
 Possibility of knocking is avoided
 No problems of flame propagation and burn duration
 Fuel flexibility
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13. Demerits
 Controlling Ignition Timing over a Range of Speeds and
Loads
 Smaller Power Output
 Cold-Start Capability
 High HC and CO emissions
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14. Challenges of HCCI/CAI
 Control over HCCI is major problem
 High peak pressure & high heat release rate
 Engine has to be stronger so heavier
 Low power range
 High carbon monoxide (CO) & Hydrocarbon (HC)
emission
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15. Future Scope
 Japan and European countries have aggressive research and
development (R&D) programs in HCCI, including both public-
and private-sector components.
 It is announced that: Ford, Nissan, Toyota, Caterpillar, Volvo,
VW, General Motors Daimler-Chrysler and Cummins Engine
Company have been performing research on HCCI
combustion.
 Recent research has greatly expanded toward understanding of
HCCI, but additional research will be required to resolve the
technical barriers, including: control of combustion timing
across the load speed map; controlling the heat release for high
load operation; cold-start and control during rapid transient
states; unburned hydro carbon emissions.
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16. Companies using HCCI engines
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COMPANY MODEL TECHNOLOGY
YEAR OF
COMMERSIALISAT
ION
General Motors
Saturn-Aura pHCCI
Test Vehicle is on the
Road
Opel-vectra pHCCI 2015
Mercedes
Dies-otto pHCCI
Test Vehicle is on the
Road
Volkswagen
Touran
CCS(Combined
Combustion Spark)
2015
GCI(Gasoline
Compression Ignition)
Ford pHCCI 2015

17. Conclusion
 The HCCI, combustion process is an interesting option to
the conventional SI and CI processes.
 HCCI engines have the potential to match or exceed the
efficiency of diesel engines without the major challenge of
NOx and PM emission control
 A high-efficiency, gasoline-fueled HCCI engine represents
a major step beyond CRDI engines for light-duty vehicles.
 HCCI engines are a promising technology that can help
decrease some of our energy issues in the near years.
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18. REFERENCES
 [1] SuyinGan, HoonKiat Ng, KarMun Pang,Homogeneous Charge Compression
Ignition (HCCI) combustion:Implementation and effects on pollutants in direct
injection diesel engines Applied Energy 88 (2011) 559–567
 [2] Xing- Cai Lu, Wei Chen, Zhen Huang A fundamental study on the control of the
HCCI combustion and emissions by fuel design concept combined with controllable
EGR. Fuel 84 (2005) 1074–1083
 [3] H Z HAO, Brunel University West London, UKOverview of CAI/HCCI gasoline
engines
 [4] Sandesh Pokharkar, Shailesh Pansare, Tushar Khandve, Manthan Pagare Review
on hcci engine ijates vol.4, issue no3, March 2016
 [5] Swapnil P. Awate, Shreya B. Bhangare, Dhairya S. Deore Homogeneous Charge
Compression Ignition Engines
 [6]Mohammad Izadi Najafabadi and Nuraini Abdul Aziz Review Article
Homogeneous Charge Compression Ignition Combustion: Challenges and Proposed
Solutions Hindawi Publishing Corporation Journal of Combustion Volume 2013,
Article ID 783789
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