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Hcci ppt by pallav


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Hcci ppt by pallav

  1. 1. Homogeneous charge Compression Ignition (HCCI) Engine A New Trend in Automobile field By Pallav V. Barhate Roll No. :- 71 PVG’s COET
  2. 2. Demerits of existing I.C.Engine <ul><li>Spark Ignition Engine- </li></ul><ul><li>1. Losses during gas exchanges </li></ul><ul><li>2. Poor Thermodynamic efficiency </li></ul><ul><li>3. Low combustion efficiency </li></ul><ul><li>Compression Ignition engine </li></ul><ul><li>1. Emission of NOx,Soot particles and PM </li></ul>
  3. 3. Diesel Engines Contribute to Multiple Air Pollutants Carbon monoxide (CO) Ozone ( NOx) Particles (PM ) ( NOx, SOx, ) Toxics - Diesel particles Greenhouse Gases - CO2, methane
  4. 4. To meet demand <ul><li>Reduction in exhaust emission ( CO2 & NOx) </li></ul><ul><li>To achieve EURO5 norms by 2010 </li></ul><ul><li>Higher Thermal efficiency </li></ul><ul><li>Energy Economy </li></ul>
  6. 6. Why HCCI Engine ? <ul><li>High efficiency and ultra low emission w.r.t conventional Diesel engine. </li></ul><ul><li>To achieve near zero NOx and soot emission to achieve latest Euro Norms ( E5) </li></ul><ul><li>To reduce fuel consumption, greenhouse gas emission. </li></ul><ul><li>( Law of Diesel HCCI – In Germany, every one percent increase of diesel HCCI car saves 90 million liters of fuel per year. This corresponds to emission saving of some 210000 metric tones of Co2 ) </li></ul><ul><li>Source- BOSCH news letter-GmbH- April 2008 </li></ul>
  7. 8. What Is HCCI? <ul><li>HCCI is a combustion process. HCCI is not an engine concept. HCCI must be incorporated in an engine concept. </li></ul><ul><li>HCCI is a low temperature chemically controlled (flameless) combustion process. </li></ul><ul><li>HCCI can be considered as a hybrid form between the diesel and Otto combustion process. </li></ul><ul><li>However combustion process is different. So there is neither Diffusion flame (as in a diesel engine) nor a flame front traveling through a premixed charge ( as in SI engine). </li></ul>
  8. 10. WORKING PRINCIPLE OF HCCI <ul><li>Homogenous charge(mixture of air & fuel) should be mixed before combustion and compress to high enough temperature to achieve spontaneous ignition of the charge. </li></ul><ul><li>Thus HCCI is similar to SI in the sense that both processes use premixed charge and that of CI as both rely on autoignition for combustion initiation. </li></ul>
  9. 11. HCCI WORKING <ul><li>Fuel injected through fuel injectors. </li></ul><ul><li>Air induction through intake plenum. </li></ul><ul><li>Air & Fuel mixed in combustion chamber. </li></ul><ul><li>As piston moves back up(compression stroke) sufficient heat has accumulated. </li></ul><ul><li>This heat (no spark) spontaneously combust A/F mixture which forces piston down for power stroke. </li></ul><ul><li>This process is lean , low temp. ,flame-less energy released. </li></ul><ul><li>Entire mix. burned simultaneously produces equivalent power using much less fuel & low emissions. </li></ul><ul><li>At exhaust stroke , exhaust valves closes early ,trapping some latent combustion heat & preserved. </li></ul><ul><li>Now small amount of fuel injected in chamber for pre-charging before next stroke. </li></ul>
  10. 12. ADVANTAGES <ul><li>15% increase in fuel efficiency over SI engines. </li></ul><ul><li>Can be operated at high compression ratios(>15). </li></ul><ul><li>Can be operate on gasoline , diesel fuel and most alternative fuel. </li></ul><ul><li>Omission of throttle losses improves efficiency. </li></ul><ul><li>No shock wave propagation ,so no knocking. </li></ul><ul><li>Cleaner combustion and lower emission . </li></ul>
  11. 13. DISADVANTAGES <ul><li>High in-cylinder peak pressure. </li></ul><ul><li>Engine wear due to high heat release and pressure rise. </li></ul><ul><li>Auto-ignition is difficult to control. </li></ul><ul><li>Small power range, constrained at low loads,high loads. </li></ul><ul><li>Carbon Monoxide(CO) & Hydrocarbons(HC) emissions are higher. </li></ul>
  12. 14. CHALLENGES OF HCCI <ul><li>Control over HCCI is major problem. </li></ul><ul><li>High peak pressure & high heat release rate. </li></ul><ul><li>Engine has to be stronger so heavier. </li></ul><ul><li>Low power ranges. </li></ul><ul><li>High Carbon Monoxide(CO) & Hydrocarbon(HC) emissions </li></ul>
  13. 15. CONTROL APPROACHES <ul><li>Variable compression ratio (VCR) </li></ul><ul><li>Variable exhaust gas percentage </li></ul><ul><li>Variable valve actuation </li></ul><ul><li>Variable fuel ignition quality </li></ul><ul><li>Direct injection PCCI or PPCI combustion </li></ul><ul><li>Variable induction temp </li></ul><ul><li>Controlling exhaust gas emissions </li></ul><ul><li>Strategies to lower rate of combustion &to reduce high peak pesssure </li></ul><ul><li>Different ways to increase the power </li></ul>
  14. 16. PROTOTYPES <ul><li>The future of HCCI looks promising specially with partial HCCI mode. </li></ul><ul><li>Major companies such as GM, Mercedes-Benz, Honda, and Volkswagen have invested in HCCI research. </li></ul>
  15. 17. CONCLUSION <ul><li>HCCI engines are more efficient than SI and CI engines. </li></ul><ul><li>Lower emission of PM and NOx to meet future norms (Euro 5 Norms ). </li></ul><ul><li>It has fuel flexibility. </li></ul><ul><li>HCCI engines will be cheaper than the presently used engines because of simplicity. </li></ul><ul><li>But </li></ul><ul><li>Control on Ignition timing is essential. </li></ul>
  16. 18. Thank you