Process of COMBUSTION of internal engines.pptx

Engine combustion process

1. STAGES OF COMBUSTION IN SI AND CI ENGINES G Nagarajan Professor & Head I . C . Engg . Division Dept. of Mech. Engg . Anna University Chennai 600025

2. COMPONENTS OF BASIC COMBUSTION

3. COMPLETE COMBUSTION

4. INCOMPLETE COMBUSTION

5. CLASSIFICATION OF I C ENGINES Spark Ignition Engine (SI engine ) Combustion process in each cycle is started by an external spark . Compression Ignition Engine (CI engine ) Combustion process starts when the air-fuel mixture self ignites due to high temperature in the combustion chamber caused by high compression.

6. TYPE OF FUEL VS COMBUSTION STRATEGY Highly volatile with High self Ignition Temperature : Spark Ignition. Ignition after thorough mixing of air and fuel. Less Volatile with low self Ignition Temperature : Compression Ignition .

7. Working of a Four Stroke SI engine

8. Combustion in SI Engines

9. CONVENTIONAL SI ENGINE

10. THEORETICAL P- θ DIAGRAM

11. STAGES OF COMBUSTION

12. DETAILS OF FLAME TRAVEL

13. KNOCK shock P,T time time P,T end-gas flame

14. ABNORMAL COMBUSTION IN SI ENGINE

15. ENGINE DAMAGE FROM SEVERE KNOCK Piston Piston crown Cylinder head gasket Aluminum cylinder head

16. Combustion in CI Engines

17. CONVENTIONAL SI ENGINE

18. DESCRIPTION OF EVENTS IN CI COMBUSTION

19. 25 Combustion in CI Engine In a CI engine the fuel is sprayed directly into the cylinder and the fuel-air mixture ignites spontaneously. These photos are taken in a RCM under CI engine conditions with swirl air flow 0.4 ms after ignition 3.2 ms after ignition 3.2 ms after ignition Late in combustion process 1 cm

20. 26 Direct Injection quiescent chamber Direct Injection multi-hole nozzle swirl in chamber Direct Injection single-hole nozzle swirl in chamber Indirect injection swirl pre-chamber

21. STAGES OF COMBUSTION

22. 28 FOUR STAGES OF COMBUSTION IN CI ENGINES Start of injection End of injecction -10 TC -20 10 20 30

23. Mixing Controlled Combustion : Spray diffusion flame. DIESEL COMBUSTION Ignition Delay Period : Fuel is injected, it does not ignite immediately. Premixed Combustion : Flame initiation event. Rapid burning of fuel prepared during ignition delay period.

24. IGNITION DELAY The fuel which enters the cylinder must undergo : Atomisation Vapourisation Mixing with air Precombustion reactions prior to autoignition

25. SCHEMATIC REPRESENTATION OF A FUEL JET

26. FUEL SPRAY

27. DISINTEGRATION OF FUEL JET

28. DISINTEGRATION OF FUEL JET

29. STEPS OF COMBUSTION PROCESS

30. KNOCKING COMBUSTION IN SI & CI ENGINES

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