Kentucky Engine Project Report

CHAPTER 1

1. INTRODUCTION: Stirling engine is an engine that works on the principle of pressure difference caused due to the temperature difference between the two chambers, such that there is a net conversion of heat energy to mechanical work. The Stirling engine is a closed cycle regenerative heat engine in which the working fluid is permanently contained within the system. The air inside the chamber expands due to the heat source and pushes the piston, thus achieving a perpetual motion. The Stirling engine is noted for high efficiency when compared to the steam engines and it has an ability to use almost any heat source. Since the Stirling engine is compatible with various energy sources such as alternative and renewable energy it

The simplified Stirling engine consists of two cylinders. One cylinder is heated by an external heat source and the other is placed at a normal temperature .the gas chambers of the two cylinders are connected and the pistons are connected to each other by a linkage that determines how they will move in relation to one another. When air inside the hot chamber expands it pushes the piston downwards allowing the air to pass through the another cylinder .The hot air cools down to the temperature of the air inside that cylinder and isothermal compression takes place and the air is passed to the hot chamber by a transfer port and thus the process undergoes simultaneously. Stirling originally regarded his engine as a perpetual motion machine ie all heat supplied would be converted into work. Due to the invention of more powerful internal combustion engine at the middle of the 19th century, the Stirling engine was abandoned. But even though, the Stirling engine had an advantage over steam engine due to its low operation cost, the only major problem with the Stirling engine was its tendency to fail when the cylinder was too hot

The beta configuration has a single cylinder with a hot end and a cold end, containing a power piston and a 'displacer ' that drives the gas between the hot and cold ends. It is typically used with a rhombic drive to achieve the phase difference between the displacer and power pistons, but they can be joined 90 degrees out of phase on a crank shaft. In a beta type the expansion and compression actions are performed in the same cylinder with only a single piston to drive. As the working fluid expands and contracts ,it drives the power piston. Beta type engines have a benefit of noy having a hot seal, since the only seal in the system. A concern though with this design is that with healing and cooling occurring in the same