Stirling Engine - Perpetual but Expensive

Stirling Engine involves a great concept and that concept is the reason why it is a forever-running and eco-friendly machine. The reason why you may not have heard about this is because its not widely used nor produced. Its applications are mainly in sub-marines or other operations where quiet operation is necessary. Although it has more potential than normal car engines its use is much less. Some reasons for that are that its expensive and difficult to maintain. You will see why as you read more. Its use is mainly by rich institutions like the Army or NASA. As you will read further you will realize that the working of this engine is really innovative and can be classified as a great innovation. Read more to know more about it.

Robert Stirling

Given the rise, in recent years, of liquid fuel prices and concerns such as peak oil and climate change, it is no wonder there has been a tremendous interest on new ways to produce energy. One of them can be the Stirling Engine.


The Stirling engine was invented by Robert Stirling in 1816 and it has many advantages. Some of them are:

• It runs on any provided heat source
• Last Longer
• Runs forever unless there is a problem
• Simpler Engine Mechanics
• Runs Quietly
• No Environmental Damage
• Needs no air supply
• Extremely Flexible

As you can see these are the very things that the world need from engines today but still Stirling Engine is not used. Why! Well there are many reasons for it:

A Small Model Showing SE'sConcept

• Size Issues
• Expensive
• Power And Torque Issues
• Requires Expert Help when gives a problem

So, now you know what is a sterling engine, who invented it, what is it and what are its advantages and disadvantages. One thing that is left is that how does it work? Well the concept behind it is simple to imagine.

The key principle of a Stirling engine is that a fixed amount of a gas is sealed inside the engine. The Stirling cycle involves a series of events that change the pressure of the gas inside the engine, causing it to do work.

                             

In order to run, the engine above requires a temperature difference between the top and the bottom of the large cylinder. In this case, the difference between the temperature of your hand and the air around it is enough to run the engine.

In the figure on this page, you can see two pistons:

1. The 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.
2. The 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.

The displacer moves up and down to control whether the gas in the engine is being heated or cooled. There are two positions:

1.  When the displacer is near the top of the large cylinder.Inside the engine most of the gas has been heated by the heat source and it expands. This causes the pressure to increase which forces the piston up.
2. When the displacer is near the bottom of the large cylinder.Most of the gas in the engine has now cooled and contracts causing the pressure to decrease, which in turn allows the piston to move down and compress the gas.

To know more about this great invention watch this planet mechanics episode in which two men try to power a farm in spain through sun's energy. One uses Solar Panels, other stirling engine.

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