Session: IMECE Undergraduate Research and Design Exposition

Paper Number: 113997

113997 - Analysis of Heat Transfer in a Hot Chamber of the Stirling Engine 

The need to search for new alternatives for the generation of mechanical energy through methods that have a low detrimental impact on the environment, this is, with the reduction of polluting emissions, has been observed.

External combustion engine has little application in our country, such as the Stirling engine, which is a good option for cogeneration. Therefore, the use of heat energy from main processes with a large flow of fluid at high temperatures and residuals, can improve performance from the overall process, and/or the use of renewable energy such as solar energy, biomass, among others.

This kind of energy generation can be beneficial for developing countries because it can easily find these energy sources from heat energy generated in the local industries.

Based on the known low efficiency of Stirling engines, i. e., not exceeding 25% and, its inefficiency in the use of heat transferred to the system through external combustion, this study performs an analysis of the most significant variables in heat transfer in a hot chamber of Stirling engine.

The boundary conditions considered according to the hot fluid, whether water or air, are the flow, pressure, and temperature. In addition it was compared different design of the hot chamber, e. g., smooth, with fins, and the material from which the chamber is made (Aluminum alloys).

This work is based on the recommendations for improvements mentioned in the capstone project tittled "Design of a Stirling engine" (Vives Miguel Angel, 2016). A CFD computational fluid dynamics and modeling was carried out in a commercial simulation software solidworks.

A control volume that surrounds the chamber was designed with the aim that the fluid at high temperature (which must be between 200° and 500° C) is in contact as much as possible to the surface and, make wall temperature uniform. This is, to a achieve better heat transfer to the fluid that is inside the chamber.

It should be noted that due to the design of this control volume, a variable added to our system are the fluid inlet and outlet holes (in terms of quantity, size, and location).

This work is done with a focus on the process that occurs externally to the Stirling engine.

The simulations were run fixing the value of one of the boundary conditions, making the others vary in search of the best possible result.

Finally, a comparison between the best output obtained in terms of heat transfer simulations is shown.

Presenting Author: Jonathan Amarilla Facultad de Ingenieria - Universidad Nacional de Asuncion

Presenting Author Biography: Mechanical Engineering student of the Faculty of Engineering of the National University of Asunción
Teaching Assistant for the subjects Technical Drawing and Physics 2
Metalworking Laboratory Assistant

Authors:

Jonathan Amarilla Facultad de Ingenieria - Universidad Nacional de Asuncion
Jorge Kurita Facultad de Ingenieria - Universidad Nacional de Asuncion