A medium temperature solar powered Stirling engine – a case of project based learning

Abstract

This paper describes the design, construction and testing of a small solar powered gamma type Stirling engine within the context of a final year degree project. The main aim was to engage the student in using theoretical and practical aspects he or she had learned in various engineering topics. The objective of the project was to size, design and construct a paraboloidal dish concentrator connected to a solar powered Stirling engine. The paraboloidal dish concentrates the sun’s energy on the hot expansion side of the engine. The engine has a capacity of 196 cubic centimetres and is tested at atmospheric pressure. Variations of its torque, power and efficiency with rotational speed are presented. A comparison between the actual and the theoretically predicted performance is also made in an attempt to validate the basic equations used for the mathematical model of the engine. At the end it is concluded that the project has provided the student with a good insight of the theory and construction of a solar powered Stirling Engine.