Single Cylinder Stirling Engine

What's Single Cylinder Stirling Engine？

Stirling engines generate power by expanding gas when heated and compressing when cold. This is an external combustion engine that continuously burns the fuel, and the vaporized expanded hydrogen (or helium) acts as a motive gas to move the piston, and the expanded gas cools in a cold air chamber, and the cycle is repeated. The single-cylinder engine is the simplest of all engines, it has only one cylinder and is the basic form of the engine. This type of Stirling engine, known as the beta configuration, features just one cylinder with a hot end and a cool end. The working gas is transferred from one end of the cylinder to the other by a device called a displacer.

The simplified model of Stirling engine can be divided into two categories: ① hot and cold cylinder split type (Alpha-type) ② cold and hot cylinder integrated type (Beta-type).

How does a single cylinder Stirling engine work?
Step 1: Most of the gas is located in the hot cylinder and is in large-area contact with the high temperature cylinder. The gas expands after being heated. Since the hot cylinder has reached the maximum volume and the cold cylinder is at the minimum volume, the gas rushes into the cold cylinder and drives the flywheel to rotate. similar to an isothermal expansion process.

Step 2: After the heated gas rushes into the cold cylinder, it contacts with the low temperature cylinder in a large area to reduce the temperature. Due to the flywheel's moment of inertia, the hot cylinder is ready to start shrinking. It is similar to an isovolumetric exothermic process.

Step 3: Most of the gas enters the cold cylinder. After sufficient cooling, the pressure begins to decrease. Combined with the rotational inertia factor of the flywheel, the gas is compressed in the cold cylinder. similar to an isothermal compression process.

Step 4: The volume of the gas is the smallest at this time, and the gas in the hot cylinder expands after being heated. Due to the position of the crank rocker, the capacity of the cold cylinder is almost unchanged, and the capacity of the hot cylinder becomes larger, returning to the state of the first step. It is similar to an isovolumic endothermic process.

The above four stages are a cycle, which constitutes the complete working process of a single-cylinder Stirling engine. The multi-cylinder Stirling engine just connects several Stirling engines of different phases to the same set of flywheels, and there is not much difference in principle.