Design and Development of Low Temperature Zero Watt Alpha Type Stirling Engine

The design and development of a low temperature alpha type Stirling engine is to be conducted. The design criterion for the engine is to produce about 10 Watts of power at 60 rpm or about 10 Joules per cycle. An 80K temperature difference is assumed with an input temperature of 380K and an output temperature of 300K. The pistons and cylinders were sourced from a high pressure foot pump to reduce fabrication time. Due to the size constraints of the purchased piston-cylinder assembly, the piston size was changed from 6.0cm bore and 5.5 cm stroke to 5.5cm bore and 6.0cm stroke. Due to the change in piston size, the work done per cycle was reduced from 10.5 Joules to 9.7 Joules. The engine failed to run during the testing stage due to poor sealing between the piston and cylinder. This prevented adequate pressure to be built in the cylinder to turn the crankshaft. It is recommended that the pistons and cylinders be replaced with either custom made components with good sealing or with pistons and cylinders sourced from high pressure pneumatic actuators. A redesign of the crank linkage to reduce side thrust might also help with the piston sealing problem. In conclusion, the engine shows promise if the problem of piston sealing can be overcome. The advantages of low noise and low maintenance allows the placement of the engine in places in accessible to conventional heat engines such as in domestic living areas as combined heat and power (CHP) generators.