Brainstorming
Researching on the Stirling Engine
A Stirling engine is a regenerative external combustion engine which converts heat to work through the cyclic compression and expansion of air at different temperatures. There are three basic models of the Stirling engine: Alpha, Beta and Gamma. We have carried out an analysis of each type below to determine which to base our project on.
Alpha          Beta        Gamma
Alpha
Characteristics:
Two power cylinders in V-shape
Pistons in separate cylinders
Both pistons connected to crankshaft
Advantages: ​
High power-to-volume ratio
Easy to manufacture and maintain
Disadvantages:
Durability of seal is compromised due to constant exposure to hot gas
More dead space due to the presence of 2 cylinders
Beta
Characteristics:
One displacement piston and one power piston
Pistons in the same cylinder
Both pistons connected to crankshaft
Advantages:
Seal is not exposed to hot gas
Less dead space as only one cylinder is used
Disadvantages:
Lower power density
Technical challenge due to lack of insulation between hot and cold ends
Gamma
Characteristics:
One displacement piston and one power piston
Pistons in separate cylinders
Both pistons connected to crankshaft
Advantages:
Seal is not exposed to hot gas
Mechanically simpler
Disadvantages:
Lower power density
More dead space due to the presence of 2 cylinders, reducing the maximum pressure of the system
Our Decision:
Taking our limited budget and resources into account, we feel that it would be the most feasible to construct a Beta-type Stirling engine.