S O L A R P O W E R E D S T I R L I N G E N G I N E 1 A. PROJECT MEMBERS LIST SOLAR POWERED STIRLING ENGINE RESEARCH PROJECT A GREEN FUND MINI-GRANT PROPOSAL UA Student Project Leader Megan McHugh 5 th year undergraduate student, Sustainable Built Environments meganmchugh@email.arizona.edu Role: Project Organizer and Student Worker Supporting Faculty Dr. Cho Lik Chan Department of Aerospace and Mechanical Engineering Professor, Associate Head for Graduate Studies, Chair of the Graduate Studies and Research Committee cholik@email.arizona.edu Role: Project Director Joseph Hartley Machine Shop Supervisor, Department of Aerospace and Mechanical Engineering hartley2@email.arizona.edu Role: Project Manager Joseph Iuliano College of Architecture, Planning and Landscape Architecture jiuliano@email.arizona.edu Role: Project Coordinator Business Manager Elizabeth Cordova College of Architecture, Planning and Landscape Architecture ecordova@email.arizona.edu Role: Business Manager B. PROJECT DESCRIPTION Overview. Funding will be used to develop a solar powered Stirling engine, which will showcase the ability of the renewable energy to be used in conjunction with external heat engines. It will be used as a demonstration on the UA mall for students and for the American Society of Mechanical Engineers (ASME) Stirling Engine Interest Group. Details of the construction of the solar powered Stirling engine, its applications, and information regarding testing and research will be recorded in a literature review and research report. The methodology section will be detailed so the machine shop supervisor, Joseph Hartley, may use it as the design piece for the class AME 313: Machine Shop in the future. The solar powered Stirling engine currently planned for construction will demonstrate the wide applications of the engine. Furthermore, it will serve as an educational demonstration to a diverse group of students at relevant UA events, such as when a prepared presentation is given to the Stirling Engine Interest Group
S O L A R P O W E R E D S T I R L I N G E N G I N E 2 members or when local high schools take part in the Stirling engine design competition being held in the spring semester of 2017. Stirling engines. In 1816, Robert Stirling invented the Stirling engine, a device that has cyclic compression and expansion of the working fluid at different temperature levels. 1 This operation is known as a closed regenerative thermodynamic cycle, and a net conversion of heat to work is accomplished by the volume change regulating the flow. 2 Low-power range solar thermal conversion units consist of three main sub-systems: the solar receiver, the thermodynamic gas circuit, and the drive mechanism. Stirling engines are considered among the most effective of these units and improvements in performance can be made based on changes in the main sub-systems. 3 A prototype Stirling engine has been constructed and is currently undergoing testing and is shown in Fig. 1. Fig. 1. Completed small-scale Stirling engine, powered here by ethanol flame although the future design will be modified to be solar powered instead. Solar power generation. The main focus of the research will be optimizing a solar powered modification of the base Stirling engine. The solar powered Stirling engine was patented in 1987 by Roelf J. Meijer. Using a large dish facing the sun, the rays of sunlight can be reflected onto a focus point at the center of the dish to collect solar energy as a source of heat. The heat then powers the Stirling engine connected to the solar dish collector and produces electricity, which makes the system a viable alternative energy source. 4 The solar powered Stirling engine has other applications as a pump, which is important as it is cost effective and can be used for water pumping in areas of the world where there is low access to 1 Stirling, R. (1816). Patent No. 4081. Edinburgh, Scotland: Chancery. 2 Thombare, D.G., & Verma, S.K. (2006). Technological development in the Stirling cycle engines. Renewable & Sustainable Energy Reviews. 12, 1-38. 3 Mancini, T., & Heller, P. (2003). Dish Stirling systems: an overview of development and status. Journal of Heat Transfer, Trans. ASME. 125, 135-51. 4 Meijer, R.J. (1987). U.S. Patent 4707990. Washington, DC: U.S. Patent and Trademark Office.
S O L A R P O W E R E D S T I R L I N G E N G I N E 3 clean water. Pumping systems employed in sunbelt countries have a maximum water cost target of 6 cents/m 3, as set by the World Bank based on their study that shows photovoltaic pumping systems currently cost 8.4 cents/m 3 and gasoline pumping systems at 8.58 cents/m 3. Sunvention Sunpulse Water has designed and constructed a prototype solar thermal water pump, which consists of a solar collector directly coupled to a slow-speed Stirling engine that can then be coupled to the water pump, or anything else that requires mechanical power. TUV labs assessed the Sunvention system and found it works at a cost of 2.4 cents/m 3 an amount that meets the World Bank target. This means that there are a large number of applications for the solar powered Stirling engine outside of electricity production and water pumping, since it can serve as an air pump for fish farms or to fulfill mechanical requirements such as milling, grinding, and compressing. 5 Designing a solar powered Stirling engine that can also meet these targets after optimization is part of the goal for continued research on the engine after its completed construction. Future directions. The solar powered Stirling engine will be constructed with the funding from the Green Fund and completed by the target deadline. However, after completion, administrative co-leader Megan McHugh and other students in the Stirling Engine Interest Group will continue the modification and optimization of the design with the supervision of Joseph Hartley and Dr. Chan. The potential applications for sunbelt countries such as producing electricity, water pumping, and mechanical operations can all be experimented with as well. Once the solar powered Stirling engine has been optimized for any of those applications, it can then potentially be used on the UA campus as a permanent sustainable installation. C. UA STUDENT INVOLVEMENT/BENEFIT Administrative Co-Leader. The administrative co-leader for this project is undergraduate student, Megan McHugh in the Sustainable Built Environments program, who will take a leadership role in the research, design development, construction, and testing of the solar powered Stirling engine. The role will also require documenting the research process and completing a research report detailing the development of the solar powered Stirling engine. This provides an educational opportunity for the student to conduct original research in the field of sustainable engineering. Student Volunteers. Student volunteers will consist members of the ASME Stirling Engine Interest Group, which includes several UA undergraduate students and a few students from local high schools. They will help by constructing various Stirling engine prototype models and providing research results and observations from testing in order to influence the modification choices made in the optimization of the solar powered Stirling engine. Experiential Learners. The ASME Stirling Engine Interest Group is developing a Stirling engine design competition for local Tucson high school and some middle school students to engage in during spring semester 2017. The solar powered Stirling engine will serve as a sustainable model for the students to learn about and will open the door to the discussion of sustainable engineering. This will be an educational opportunity to get high school students not just involved in STEM, but to get them to think about how sustainable alternatives can be implemented in traditional fields such as mechanical engineering. High school students who are participating in the Stirling engine design competition will be informed about the solar powered Stirling engine through presentations given by the administrative coleader, Megan McHugh, which will include demonstrations of the engine working. Once the website for 5 Ardron, Mitra. Sunvention SunPulse Water Solar Thermal Pump. 2010. Print.
S O L A R P O W E R E D S T I R L I N G E N G I N E 4 the UA Stirling engine competition is running, a page will be dedicated to an accessible explanation of what the solar powered Stirling engine is and what the sustainable applications are. The model will also remain on display in the machine shop of the UA Aerospace and Mechanical Engineering building. D. PROJECT TIMELINE October 2016 (completed) November 2016 December 2016 January 2017 February 2017 March 2017 April 2017 Complete base model of the Stirling engine and make sure that it is working; research solar powered modifications and begin designing the optimal small scale solar powered Stirling engine; begin writing literature review for the final research report. Green Fund Committee open public meeting decision on funding; order parts and materials needed for the project; begin work in the machine shop on the Stirling engine modifications for any materials that come in. Complete construction of the base solar powered Stirling engine; finish writing the introduction, literature review, and up to date methodology section of the research report. Run tests and collect data on the base model; make modifications to the solar powered Stirling engine to optimize its efficiency; prepare presentations to explain the engine to students. Continue modifications, testing, and data collection in order to confirm any changes are increasing the engine efficiency; write the data and results section of the research report; demonstrate working engine to students. Finalize the solar powered Stirling engine design and complete its construction; write the discussion and conclusion of the research report and have it edited. Create a poster detailing what the solar powered Stirling engine is, what the research project accomplished, and what the sustainable applications of engine are; upload the research report and poster to the UA Repository; display the final model in the Aerospace and Mechanical Engineering building where it can be reused to demonstrate its solar powered applications in the future. E. MARKETING The Green Fund will be listed as a sponsor with the logo displayed on the final poster and on any presentations that are given involving the solar powered Stirling engine. The Green Fund logo will also be engraved in the base of the solar powered Stirling engine. An example of the current engraving on the base Stirling engine model is shown in Fig. 2.
S O L A R P O W E R E D S T I R L I N G E N G I N E 5 Fig. 2. Engraving of wildcat logo and University of Arizona text currently on the base Stirling engine model. F. METRICS Desired Impacts. The solar powered Stirling engine will be used to demonstrate new renewable energy technologies on campus and bring awareness to students about the positive impacts solar power generation can have along with the additional applications the Stirling engine provides to sunbelt countries. Outreach will be made through the ASME Stirling Engine Interest Group with a presentation given to the students there and later given to the high school students who will be competing in the Stirling engine design competition. Strategies. To accomplish the desired impacts a presentation and poster will be made as part of the completion of the project by the deadline. Scheduled times to present the solar powered Stirling engine to the various student groups will be set throughout the spring semester. The engine will remain in the machine shop of the AME building and can continued work on its modification and optimization will be done by the Stirling Engine Interest Group as supervised by Joseph Hartley and Dr. Chan. Plan for Measuring and Reporting. The number of students who attend presentations and witness the demonstration of the solar powered Stirling engine working will be measured and recorded. It may also inspire students to look for alternative energy solutions where applicable in engineering and use a
S O L A R P O W E R E D S T I R L I N G E N G I N E 6 renewable strategy such as solar power for their Stirling engines entered into the design competition. Any of these quantitative or qualitative impacts will be included in the final report submitted to the Green Fund after the completion of the project.