Elbel makes case for two-phase ejector technology
Stefan Elbel, a research assistant professor and lecturer in MechSE, was recently invited to write a guest column for the September issue of Accelerate America, a print and online industry magazine that promotes the use of sustainable, natural refrigerants in North America.
In his article, “Ejectors: Solution to the CO2-Equator Conundrum,” he noted that, “two-phase ejector technologies can bring COP [coefficient of performance] improvements on the order of 20 to 30 percent in the most demanding outdoor conditions. Numerous studies carried out at universities, such as the Air Conditioning and Refrigeration Center (ACRC) at the University of Illinois at Urbana-Champaign (UIUC), and also at independent third-party industry labs, such as Creative Thermal Solutions, Inc. (CTS), have confirmed these results.”
He earned his MS (2003) and PhD (2007) in mechanical engineering from Illinois. He is interested in experimental and numerical research in the areas of thermodynamics, fluid mechanics, and heat transfer. His focus is on energy conversion systems with specialization in vapor compression technology using synthetic and natural refrigerants. He conducts both fundamental and applied research on components and systems used in mobile, residential, commercial, and industrial heating and cooling applications.
Elbel has been researching transcritical carbon dioxide cooling and heating cycles for a large variety of applications for more than 15 years. He has worked extensively on designing and improving refrigerant ejector systems to increase the energy efficiency of vapor compression cycles. His interest in expansion work recovery has been extended to vortex tubes that offer attractive improvement potentials at very low cost. He is also working on waste heat recovery systems that allow the efficient generation of waste heat driven cooling as a promising alternative to absorption cooling systems.