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

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

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………

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.

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 .

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

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

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

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.

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

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

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

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

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.

Complete Setup

Data Compatibility

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

Calculations (Contd.) Indicated power (I.P.) = P mean *cylinder volume * no. of power stroke per sec. = (5 bar*100cc*810)/60 = 0.675 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%

Operational Video

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

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.

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.

Thank You Q&A