1. COMPRESSED AIR ENGINE (An engine which runs on Air only)
(to Develop a compressed air engine)
Jitin yadav
Automobile Engineer

2. In India …… Increasing Fuel Price Increasing Global warming
Increasing Emission
Increasing Transportation
So, We are putting effort to find out the solution…

3. Introduction If the engine runs on compressed air then there is …
Zero Emission
Outlet have low temperatures so ambient temperature can be reduced
Outlet air can be recycled to it feed again in induction
Eco friendly
Clean India………

4. Principles and Laws
An increase in pressure equals a rise in heat and compressing air creates a proportional increase in heat.
If a volume of air is halves during compression, then the pressure is doubled.
Volume of a gas changes in direct proportion to the temperature.
Compressed air is normally used in pressure ranges from 1 bar to 414 bar (14 to 6004 psi) at various flow rates.

5. Basic Thought Pressure develop in S.I. engine is about 14 to 20 bar
So for same power, we needed more than 20 bars.
As pressurized air comes in there is expansion of about 5 times so the air pressure reduces by 5 times.
So we have to supply 5 times more pressure as required.
Their will be leakage of about 15% in the engine .

6. Requirements for AIR ENGINE
Air tank (300 bar for tank)
High Pressure Air (30 bar for inlet)
Engine (Modification Required)
Pressure Gauges (upto 500 bar)
Air feed lining (hoses)
Nozzle
Safety valves
Dynamometer

7. Technical Considerations
Sealing of Joints and leakage
Machine oil lubrication because of low temperature operation
Remove all the restriction from intake and silencer
To make more power stroke we have to redesign the camshaft for double the lift in 720 degree revolution of 4 stroke engine

8. Compressed Air Pressure
Required Tank Pressure is 300 bar and Pressure at delivery 20 to 30 bar
Required Tank Capacity – 55 to 300 liters
Desired if air is preheated before supplying it in cylinder
Available Tank – 55 liters, Max pressure – 150 bar

9. Old Engine Design Consideration
Old Engine – Bajaj Boxer, Single Cylinder, 4 Stroke
Specification – 7 HP, and Torque 7.44 Nm at 5500rpm
Compression ratio - 10
The old camshaft has only one lift for each valve for 720 degree revolution.

10. Valve timing for 4 stroke engine
Old Camshaft Design
4 Stroke cam shaft
Valve timing for 4 stroke engine
Operation

11. New Concept Engine Decided to convert the engine in 2 stroke engine
Changed its camshaft
Two lift for both intake and exhaust valve (720 degree revolution of crankshaft)
Removed all the intake air restriction exhaust manifold and silencer

12. New Camshaft Profile Design
Dia. Of base circle – 20mm, Dia of pitch curve – 30 mm
Dwell Period – 5 degree, Motion of follower - Uniform Velocity
Angle of ascent (a) – 87.5 degree Angle of descent (b) – 87.5 degree
Lift or stroke – 5mm

13. New Camshaft Design New Camshaft Design and Dimensions
Inlet Cam Dimensions
Base Diameter : 20 mm.
Lift : 5 mm
Open/Close : 5 degree / 90 degree
Thickness : 12 mm
Outlet Cam Dimensions:
Base Diameter: 20 mm
Lift : 5 mm
Open/Close : 85 degree / TDC
Thickness : 12 mm.
New Camshaft Design and Dimensions

14. Assembling the components
Material for new camshaft - Die steel
Old camshaft is replaced by new cam shaft at same place
New bearing is used (6002 or 6003)
Same mounting are used for the new camshaft with new design
Mounted the engine on the frame.
Connected it with Air tank via hoses.

15. Complete Setup

16. Data Compatibility

17. Calculations Mass Flow Rate = Amount of air consume/ Time Taken
It takes 16.2 seconds for reducing pressure from 9 bar to 5 bar
From mole calculation or pV=nRT
T=Constant in expansion process
Volume V = 50liter
Mass flow rate = 960 gm per min.
Mean effective pressure
= area in PV curve (net work done)/Swept volume
Area in PV diagram = 0.5*Base*Height
Swept Volume = 90cc
Mean Effective pressure = (0.5*90cc*10 bar)/90cc 
= 5 bar

18. Calculations (Contd.) Indicated power (I.P.)
= P mean *cylinder volume * no. of power stroke per sec.
= (5 bar*100cc*810)/60
= kW
Brake Power = Brake torque* RPM
=(2*3.14*N*W*L)/60
=0.33kW
Mechanical Efficiency
= Brake Power/ Indicated Power
= 0.33/0.675
=48.8%

19. Operational Video

20. Future development in Our project
High pressure Tank for air supply
Double staging of the compression air
Preheating of air supply for winter operations
Recycling of air by using any free energy
Diagnosis of Air filter

21. Advantages and Benifits
Compressed air technology reduces the cost of vehicle production by about 20%, because there is no need to build a cooling system, fuel tank, spark plugs or silencers.
Transportation of the fuel would not be required due to drawing power off the electrical grid. This presents significant cost benefits.
Pollution created during fuel transportation would be eliminated.
Air, on its own, is non-flammable, abundant, economical, transportable, storable and, most importantly, non polluting.
High torque for minimum volume.

22. Potential Advantages over Electric Vehicle
No degradation problems associated with current battery systems.
Much like electrical vehicles, air powered vehicles would ultimately be powered through the electrical grid which makes it easier to focus on reducing pollution from one source, as opposed to the millions of vehicles on the road.
Compressed-air tanks can be disposed of or recycled with less pollution than batteries.
The tank may be able to be refilled more often and in less time than batteries can be recharged, with re- fuelling rates comparable to liquid fuels.
The tanks used in a compressed air motor have a longer lifespan in comparison with batteries, which, after a while suffer from a reduction in performance.

23. Thank You
Q&A