Analysis Of Stirling Engine

3.1 THE STIRLING CYCLE

Stirling engines exhibit the same processes compression, heating, expansion and cooling. Stirling engines operate on a closed thermodynamic cycle. Working fluid undergoes cyclic compression and expansion in separate chambers with varying volume. In a typical Stirling engine, a fixed amount of gas is sealed within the engine, and a temperature difference is applied between two piston cylinders. As heat is applied to the gas in one cylinder, the gas expands and pressure builds. This forces the piston downwards, performing work. The two pistons are linked so as the hot piston moves down, the cold piston moves up by an equal distance. This forces the cooler gas to exchange with the hot gas. The flow passes through the regenerator, where heat is

Process 1-2: Isothermal compression. Cold piston compresses the working fluid within the compression volume. This increases the pressure of the system at a constant temperature.

2. Process 2-3: Isochoric transfer I. Both pistons move in opposition (90° out of phase) to transfer the working fluid from compression to expansion volume. The regenerator, in an ideal situation, raises the fluid temperature to 3’ using heat stored from process 4-1.

3. Process 3-4: Isothermal expansion. The expansion piston is moved by the expanding fluid, which is maintained at a constant temperature by the external heat source. Work is done in this stage on the piston by the working fluid.

4. Process 4-1 Isochoric transfer: Both pistons work to transfer the fluid from the expansion to the compression space. The regenerator absorbs heat from the fluid, reducing the fluid temperature to that at 1’.

3.2 Selection of Stirling engine The type of stirling engine is most important thing for the project. We have referred different books and literature. We saw the videos and read the articles about the stirling engine. Finally, we decided to built the Alpha type stirling engine from the two cylinder V type air