Design Of Hybrid Striling Engine

Abstract

This project was set out to with an objective to explore the practicality of power production from a Hybrid Stirling engine. This would include research, design and fabrication. Hybrid here meant that the engine model would run on different sources of sufficient external heat to generate the desired motion. This was done to supplement the government‟s efforts to provide affordable electricity to rural and marginalized parts of Kenya. With this end in sight, a thorough and comprehensive research was carried out on the working and configurations of Stirling engines. Research sources included the internet, engineering books on thermodynamics and engine machines as well consulting the project supervisor. In total, knowledge gathering took about six weeks. After it was decided that the Gamma configuration would best achieve the intended objective, sketches were made. This was then followed by the first design that was drawn up using the Rhinoceros Software, that led to the second and later third (final) designs using the Autodesk Inventor Software. After all the designs were approved by the project supervisor, an acquisition was made for funds and materials. This was then followed by fabrication, assembly and testing that span a period of 8 weeks. Test results revealed that the assembled engine had air leaks that mostly emanated from the piston cylinder. The piston cylinder was the highest precision part and also most expensive. The setback meant that the project needed more investment. Constrained by monetary resources, the project was concluded and further recommendations were drawn. From the theoretical analysis, the Stirling engine designed had and efficiency of about 7.7%. This was pointed out that there were energy losses, which were attributed to friction and the engine having some out-of-balance masses. To rectify this, it was proposed that a kinematic assessment of the engine be carried out to eliminate any out of balance masses. Upon completion of the project, it was recommended that more investment in the Stirling engine project needs to be made. Emerging economies such as India have turned to use of Stirling engines to provide electricity to the rural poor. In addition, developed economies such as the United States are taking advantage of this technology to generate electricity in „solar farms‟ using large solar powered stirling engines