28-05-2014, 12:16 PM
Technical paper On STIRLING ENGINE
STIRLING ENGINE[.pptx (Size: 665.49 KB / Downloads: 30)
INTRODUCTION
Doubtful that any of us would be able to imagine modern travel without an internal combustion cycle. Hell if we ask our mechanic if he has ever seen a vehicle without any exhaust then he is probably going to refer to you to the nearest shrink.
So an engine without any exhaust gas is a mirage or it can be a reality? The answer for this is definitely yes. We can have an engine without any exhaust gas and that is what a Stirling engine is.
STIRLING ENGINE
The Stirling engine is a heat engine that is vastly different from an internal combustion engine. Stirling engines have two pistons that create a 90-degree phase angle and two different temperature spaces. The working gas in the engine is perfectly sealed, and doesn't go in and out to the atmosphere. The Stirling engine uses a Stirling cycle, which is unlike the cycles used in normal internal combustion engines.
The gas used inside Stirling engine never leaves the engine. There are no exhaust valves that vent high-pressure gases as in petrol or diesel engine, and there are no explosions taking place.
The Stirling cycle uses external heat source, which could be anything from gasoline to solar energy to heat produced by decaying plants. No combustion takes place inside cylinder of the engine.
TWO PISTON TYPE STIRLING ENGINE
The two-piston type Stirling engine uses two power pistons. Out of the two pistons one is hot piston, which is used in hot chamber, and the other one is a cold piston used in cold chamber. The space above a hot piston is always heated by a heat source. The space above a cold piston is cooled always by cold air.
DISPLACER TYPE STIRLING ENGINE
cooled always by cold air. The displacer piston displaces hot air and cold air.The displacer type Stirling engine uses a power piston and a displacer. The space below a displacer piston is always heated by a heat source.
PARTS OF A STIRLING ENGINE
Main chamber: It is the chamber where a fixed amount of gas is sealed initially. Inside this chamber only expansion and compression of gas takes place.
Output Shaft: It is horizontal and mounted several inches above the main chamber. The end of shaft centered over the main chamber has a crank and connecting rod, which drives the displacer.
Displacer: This is the large piston in the drawing. This piston is very loose in its cylinder, so air can move easily between the heated and cooled sections of the engine as the piston moves up and down.
Power piston: This is the smaller piston at the top of the engine. It is a tightly sealed piston that moves up as the gas inside the engine expands.
Crankshaft: The crankshaft is made up of steel, which passes through the bearing and receives the crank disc .the crank disc forms mount for flywheel.
Regenerator: The regenerator is constructed of material that readily conducts heat and has a high surface area.
STIRLING CYCLE
The key principle of Stirling engine is that a fixed amount of gas is sealed inside the engine.
The Stirling cycle involves a series of events that change the pressure of gas inside the engine, causing it to work.
Stirling engine uses two cylinders, one cylinder is heated by an external heat source and the other is cooled by an external cooling source. A linkage that determines how they will move in relation one another connects the gas chambers of the two cylinders to each other mechanically.
SUMMARY
The Stirling engine, types, parts; working cycle, advantages along with recent applications has been empounded in this paper.
The Stirling engine is the engine, which uses the gas sealed inside the cylinder. The expansion and contraction of the gas, using heat from external source, creates the useful work. This engine can work on any type of fuel whether it is conventional or non-conventional fuel. And the basic advantage of this engine is that the amount of gas inside the chamber remains fixed that is there is no exhaust and hence this engine is pollution less.
Due to this pollution free and use of any type of fuel characteristics the Stirling engine has greater potential over any other type of engine existing today. Hence this engine is highly preferred in automobile sector finding its application in submarines to hybrid cars. Due to the above specified advantages the striling engine is giving a cutting edge to all other engine existing today and is viewed as an answer to the existing energy crisis.