1. Performance and Emission Analysis on Oxygen Enriched variable
compression ratio Diesel Engine
SREESANKAR J
M.E THERMAL ENGG
SNS COLLEGE OF TECHNOLOGY
COIMBATORE-35

2. Abstract
In this work, the investigation is carried out in variable compression ratio diesel engine with air side oxygen enrichment.
This investigation aims to find out the optimum level of performance with various flow rates of oxygen and for various compression ratios.
Initially the base line engine performance and emission characteristics are determined at different loads with different flow rates of oxygen.

3. Abstract The experimental investigation shows that :
Increase brake thermal efficiency of the engine
brake specific fuel consumption and total fuel consumption decreases
The emission result indicates that there is a significant amount of reduction in CO emissions with the increase in flow rate of oxygen.

4. INTRODUCTION
Diesel engines have considerable advantages in the market in the form of its power output, fuel economy and durability.
environmental concerns and the emission regulations, said that to reduce emission of diesel engine simultaneously while keeping up a good fuel economy and power output.
The IC engine is to produce mechanical power from chemical energy which is contained in the fuel.
In recent years, growing concerns about environmental preservation have created a demand for a lower pollution automotive diesel engine.

5. LITERATURE REVIEW
Watson, et al conducted experiments with oxygen-enriched air (up to 30% O2 by volume). They achieved about 80% reduction in smoke at full load and 5% to 12% increase of thermal efficiency and also a decrease of CO and HC emissions. However, NOx emission increased due to the increase of oxygen concentration and cycle temperatures.
Poola, et al conducted experiments with oxygen enriched air in SI engine to reduce HC and CO emissions. It had a great advantage in the period where the catalytic converter temperature was below light off level. They achieved about 60% to 70% reduction in HC and CO emission levels with an increase of 23% of oxygen by volume.

6. EXPERIMENTAL SETUP
An oxygen cylinder is connected to the inlet manifold of the diesel engine.
oxygen flow meter is connected at the beginning of the connection from the oxygen cylinder.
A mixing chamber is fixed to the inlet manifold of the engine for effective mixing of oxygen and air.

7. Engine configurations

8. Experimental Setup

9. Oxygen flow meter

10. Mixing Chamber

11. Experimental Setup
Initially the experiment is conducted on a baseline engine which means without making any hardware modifications on the engine and the performance and emission characteristics are measured.
The oxygen flow meter is used for setting up the various flow rates of oxygen in litres per minute.
The flow rate of the oxygen is varied from 1 litre per minute to 7 litres per minute.

12. Experimental Setup
For each flow rate of the oxygen the load is varied from no load to 8 kg and at each load condition, the performance and emission characteristics of the engine is examined and the results are compared with the performance and emission characteristics of the baseline engine which is not connected with the oxygen cylinder.
The same procedure is applied to five different compression ratios which vary from 14:1 to 18:1 and the performance and emission characteristics are examined with oxygen being injected into the inlet manifold of the engine through a mixing chamber at various flow rates.

13. Measuring Methods
brake thermal efficiency and fuel consumptions are calculated by measuring the fuel inlet flow rate to the engine which is measured using a burette along with scale.
the exhaust emissions are measured with the help of exhaust gas analyzer (Kane-May 900 Combustion Analyzer and smoke meter.

14. RESULTS AND DISCUSSION
The brake thermal efficiency of the engine was found to have a gradual increase with increase in oxygen flow rate.

15. Load vs brake thermal efficiency (C.R.14:1)

16. Load vs brake thermal efficiency (C.R.15:1)

17. Load vs brake thermal efficiency (C.R.16:1)

18. Load vs brake thermal efficiency (C.R.17:1)

19. Load vs brake thermal efficiency (C.R.18:1)

20. RESULTS AND DISCUSSION
The maximum brake thermal efficiency was experienced at flow rate of 7 liters/minute at the Compression ratio of 17:1

21. RESULTS AND DISCUSSION
The specific fuel consumption decreases with increase in the flow rate of oxygen.

22. Load vs Specific fuel consumption (C.R.14:1)

23. Load vs Specific fuel consumption (C.R.15:1)

24. Load vs Specific fuel consumption (C.R.16:1)

25. Load vs Specific fuel consumption (C.R.17:1)

26. Load vs Specific fuel consumption (C.R.18:1)

27. RESULTS AND DISCUSSION
The lowest specific fuel consumption was experienced at an oxygen flow rate of 7 liters/minute and at a compression ratio of 18:1.

28. RESULTS AND DISCUSSION
The emission analysis shows that with the increase in oxygen flow rate there was a significant reduction in CO emissions.

29. Load vs CO (C.R.14:1)

30. Load vs CO (C.R.15:1)

31. Load vs CO (C.R.16:1)

32. Load vs CO (C.R.17:1)

33. Load vs CO (C.R.18:1)

34. CONCLUSION
The brake thermal efficiency is increased with increase in load and oxygen flow rate and the maximum of which was experienced at oxygen flow rate of 7 liters/minute and at the Compression ratio of 17:1.
The specific fuel consumption was gradually reduced with increase in load and oxygen flow rate and it was lowest at the oxygen flow rate 7 litres per minute.

35. CONCLUSION
The CO emissions were found to be reduced gradually with increase in oxygen flow rate and it was lowest at the oxygen flow rate of 7 liters per minute.
The NOx emissions were found to be increasing gradually with increase in load and oxygen flow rate and which is due to increased combustion temperatures and oxygen concentration.

36. CONCLUSION
The performance and emission characteristics of the engine were found to be optimum at the Compression ratio of 16:1.
So, the engine can be operated efficiently by setting the compression ratio to 16:1.

37. REFERENCES
G A Karim and G Ward., ”The Examination of the Combustion Process in a Compression Ignition Engine by Changing the Partial Pressure of Oxygen in the Intake Charge,” SAE Paper No
H C Watson, et al., ”A New Look at Oxygen Enrichment in Diesel Engine,” SAE Paper No
R B Poola, et al., ”Utilizing Intake Air Oxygen-enrichment Technology to Reduce Cold-phase Emissions,” SAE Paper No
R J Donahue and D E Foster., ”Effect of Oxygen Enhancement on the Emission from DI Diesel via Manipulation of Fuel and Combustion Chamber Gas Composition,” SAE Paper No
Theodoros C. Zannis and Dimitrios T.Hountalas., ”DI Diesel Engine Performance and Emissions form the Oxygen Enrichment of fuels with Various Aromatic Content,”.. ACS Paper No
Sekar, R., Murr, W., Schaus, J., Cole, R. et al., "Cylinder Pressure Analysis of a Diesel Engine Using Oxygen-Enriched Air and Emulsified Fuels," SAE Technical Paper , 1990, doi: /

38. REFERENCES
Marr, W., Sekar, R., Cole, R., Marciniak, T. et al., "Oxygen-Enriched Diesel Engine Experiments with a Low-Grade Fuel," SAE Technical Paper , 1993, doi: /
Virk, K., Kokturk, U., and Bartels, C., "Effects of Oxygen-Enriched Air on Diesel Engine Exhaust Emissions and Engine Performance," SAE Technical Paper , 1993, doi: /
Desai, R., Gaynor, E., Watson, H., and Rigby, G., "Giving Standard Diesel Fuels Premium Performance Using Oxygen-Enriched Air in Diesel Engines," SAE Technical Paper , 1993, doi: /
Desai, R. and Watson, H., "Effects of Fuel Composition on D.I. Diesel Engine Particulates and Study of Oxygen-Enriched Diesel NO Formation," SAE Technical Paper , 1997, doi: /

39. THANK YOU