The Stirling Engine was invented in 1816, and has the potential to be far more fuel efficient than gasoline and diesel engines.
The major features of the Stirling Engine
· The gasses that are inside the Stirling Engine never actually leave.
· There is no internal combustion – no explosions – so the Stirling Engine is very quiet.
· The Stirling Engine uses an external heat source, which can be non renewable sources such as gasoline, or renewable sources such as solar power.
The science behind the Stirling Engine
There is a fixed amount of gas in the Engine. As the temperature rises, the gas expands and pressure increases. As the temperature cools, the gas cools and the pressure decreases.
A simple Stirling Engine would consist of 2 cylinders and a gas chamber connecting these 2 cylinders. One cylinder is heated using an external heat source. The other is cooled using an external cooling source. The Stirling Cycle is as follows:
1. The heat in the first chamber heats and expands the gas, forcing the piston in thefirst chamber down. This action does the work of the engine.
2. As the first piston moves back up, the second piston moves down and the gas enters the second chamber where it is cooled.
3. As the gas is cooled it is compressed and the second piston moves back up. The gas is forced back into the gas chamber.
4. As the gas starts to heat up again it moves into the first chamber pushing the first piston down, repeating the cycle.
The advantages for the Stirling Engine is that it is very quiet and that it can be carbon neutral if the external sources are emission free.
The disadvantages are that the gas is heated and cooled by external sources, it takes time to respond. The engine needs time to warm up before producing power that can be utilised. The engine also takes time to change power output.
Although the Stirling Engine probably won’t replace the internal combustion engine, it is possible to be used in a hybrid powered vehicle.