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Samuel Bolufemi
The Technical and Economic Analysis of Vapor Compression Systems in Refrigeration Samuel Bolufemi
Mentor: Shahin Shafiee Department of Mechanical Engineering
Introduction: Vapor-compression systems transport heat through a closed-loop cycle by compressing, condensing, expanding, and evaporating a working fluid (refrigerant). While vapor-compression equipment can use many working fluids, most systems use several conventional fluorocarbon refrigerants explicitly designed for HVAC applications. Unfortunately, these traditional refrigerants used in vapor-compression systems have detrimental environmental impacts when released into the atmosphere through leaks and other losses during installation, repair, and removal. Addressing the issues with conventional refrigeration will require significant action within the HVAC industry to balance high-GWP refrigerants' phase-down with the rising consumer demand for HVAC and other refrigeration systems. Researchers have identified several low-GWP alternatives; however, many of these systems suffer from undesirable characteristics, which poses significant concerns. Although work is underway to develop alternative refrigerants and improve refrigerant management strategies, HFCs' phase-down will impose constraints on vapor-compression equipment that will require trade-offs among cost, efficiency, and safety. These constraints could present market opportunities for alternative space-conditioning technologies. Some alternative technologies are impractical for spaceconditioning applications due to low efficiencies and capacities (e.g., pulse-tube and vortex-tube cycles). Some are too early in their development cycle to be fully evaluated (e.g., Bernoulli heat pump, critical-flow cycle, and electrocaloric heat pump). Solid-state, electro-mechanical, and thermally driven technologies. The work will show the advantages and disadvantages of conventional and non-conventional refrigeration systems with an aim for them to be applicable in air conditioning. This knowledge helps better understand potential development and research directions in this field. The idea will help address excessive energy consumption, carbon footprint, and environmental hazards with conventional refrigeration. Materials and Methods: An extensive literature review was conducted to gather information for the research topic. This literature review focused primarily on two cases; Conventional refrigeration systems used in industry and Refrigeration systems currently in the research and development phase. For each refrigeration system discussed, a complete study of its working principle, advantages, and disadvantages, as well as challenges, were documented and collected in an organized report. Information was gotten from a large variety of sources; journals, websites, technical papers, e.t.c. All sources identified and used were properly cited using ASME format. Results and Discussion: This project's primary aim was to research an alternative form of refrigeration that would be less energy extensive and more efficient than the commonly used systems available in today's market. After studying a good number of systems, it was found that magnetic refrigeration, despite its limitations, had a lot of potentials and could be a very efficient alternative. As of today, vapor compression is the most common and efficient form of refrigeration, but its refrigerants are very harmful to the environment when exposed. It also uses up a lot of energy. On the other hand, magnetic refrigeration does not require any refrigerant to operate; it works using the magnetocaloric effect – applying an electromagnetic field to a particular solid to change its temperature. Although magnetic refrigeration has its challenges with cost and availability, a fully operational system can yield a higher COP ( Coefficient of Performance ) than other systems, and it's a much more environmentally friendly alternative. Research on magnetic refrigeration has barely scratched the surface, so it is an up-and-coming prospect. Conclusion(s) or Summary: This project did not require experiments of any sort; it was purely a literature review of different refrigeration systems. As it stands, the research project is not complete. Due to
graduation, I will be handing over my work to another student on our research team to continue next semester. From my findings, the conclusion is that there is a lot of potential with the refrigeration systems in research and development because they can significantly lower energy consumption while being more efficient. The main challenge is enabling these systems to compete in the market and become an affordable option for household/ conventional use. This is where the next phase of this research project, the economic analysis, becomes very critical. References: The references for this project are all listed in the actual report.
