ELECTRICITY GENERATION BY COMPRESSED AIR DEPARTMENT OF MECHANICAL ENGINEERING Group Members: Neeraj Yadav Rakshit Sehgal M. Srikanth Mahesh Yadav Aakriti Rupal

INTRODUCTION Since it is a known fact that the fossil fuels (petrol, diesel etc.) are like blood for the automobiles and are going to get dried up by the end of this present century, so it is very important to venture new concepts, ideas and designs for building automobiles for the future which would run without the use of the fossil fuels.If we succeed in creating such a machine then it will revolutionalise the whole world. The question that remains is what is the idea ? The answer lies ahead in the following slides of this presentation. The Compressed Air Engine and use it to produce electricity.

PURPOSE OF OUR PROJECT The purpose of making a compressed air engine is to produce electricity that is available at cheap rates and is environment friendly.

INTRODUCTION Before going to the main project we first see how an engine works in a nutshell The parts of an internal combustion engine are as follows:- Cylinder Piston Connecting rod Camshaft Inlet & Exhaust valves Crank & Crankshaft

INTRODUCTION The piston moves from Top Dead Center (T.D.C.) to Bottom Dead Center (B.D.C.). The inlet valve opens allowing fresh mixture of air and water known as charge to enter the cylinder. The piston moves from B.D.C to T.D.C thereby compressing the charge. The spark plug sets off a spark thus the charge combusts and pushes the piston down thereby producing power. The reciprocating motion of the piston is converted into the rotary motion of the crankshaft. The waste gases are pushed out by the piston via exhaust valve when again the piston moves from B.D.C to T.D.C. The opening and closing of the valves is controlled by the camshaft.

Explanation via Video with an explicit view of working of cams

THE AIR ENGINE First of all we will see why this air engine is required, here are some points supporting it: To save fossil fuels for the future. This concept can be used to reduce pollution caused due to emission of poisonous gases by these fuels. Although CNG (compressed natural gas) has turned out to be an alternative for petrol and diesel but natural gas itself is a fossil fuel which will get exhausted. Automobiles and other machines can become very economical. Probability for the engine to blow due to any reason can be reduced to nil. Last but not the least for the production of electricity for domestic purpose which is our project.

MAKING THE AIR ENGINE In order to give a practical sense to the conceptual idea of compressed air engine we make a model by conducting an experiment on a 4-stroke engine by modifying its “camshaft”. A camshaft is basically a shaft to which a cam is fastened or which a cam forms an integral part. In internal combustion engines with pistons the camshaft is used to operate poppet valves (these are the valves which regulate the flow of fuels).It then consists of a cylindrical rod running the length of the cylinder bank with number of oblong lobes or cams protruding from it, one for each valve. The cams force the valves open by pressing on the valve, or on some intermediate mechanism as they rotate. Now back to the model the camshaft modifications are done in order to eliminate the compression cycle, thus making the 4-stroke engine to a 2- Stroke engine.The basic idea of eliminating this cycle is that the compression cycle would try to compress the air that has been forced to the engine, which would cause the engine to stall. The advantage is that there is no point in the cycle where both valves are closed, thus eliminating any compression or suction that could slow down the piston.

A 3D MODEL OF THE CAM

MAKING THE AIR ENGINE In the previous animation we saw how a standard camshaft is made with special view of the cams which helps the poppet valves to open and close and how the whole camshaft is assembled. For the success of our project we have to modify these cams only by using different manufacturing processes. In the following slide we see the image of a modified camshaft.

MODIFIED CAMSHAFT Unmodified cam shaft Top view of modified cam (we see the cam is rugby ball shaped)

ELECTRICITY PRODUCTION An induction generator or asynchronous generator is a type of AC electrical generator that uses the principles of induction motors to produce power. Induction generators operate by mechanically turning (i.e. air engine) their rotor in generator mode. In generator operation, a prime mover (Air engine) is driving the rotor above the synchronous speed. Stator flux still induces currents in the rotor, but since the opposing rotor flux is now cutting the stator coils, active current is produced in stator coils, and motor is now operating as a generator, and produce electricity.

Use Of Induction Generator Induction generators have the ability to produce useful power at varying rotor speeds. These are mechanically and electrically simpler than other generator types.

Overview of a Typical Generator

PROJECT FLOWCHART Compressed air from tank Air enters the modified engine Modified Cam controls the inlet and outlet valves Reciprocating motion of the engines Crank shaft is rotated Shaft coupled with generator armature Armature coil rotate in magnetic field Electricity produced