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The Topology of Positive Displacement Compressor Technology and its Impact on Decarbonization and Energy Efficiency

Event Type
Mechanical Science and Engineering
4100 Sidney Lu Mechanical Engineering Building
Feb 13, 2024   4:00 pm  
Professor Craig Bradshaw, Mechanical and Aerospace Engineering, Oklahoma State University
Amy Rumsey
Originating Calendar
MechSE Seminars


Heat pump systems have the potential to reduce global carbon emissions by at least 500 million tons by 2023 (IEA). Compressors can consume up to 80% of heat pump energy consumption, making efficient compression a critical component for decarbonization goals. This talk will explore the connection between the geometric features positive displacement compressor technologies and explore the impact on a decarbonized future. Three compressor technologies, scroll, spool, and peristaltic, are discussed and analyzed using the mechanistic chamber modeling approach. The scroll and spool are traditional positive displacement compressors that each uniquely optimized based on manufacturing and thermodynamic constraints. Then they are each analyzed at various scales with a wide variety of low-Global Warming Potential (GWP) refrigerants and compared against each other and other technologies such as centrifugal and piston machines. The results show that the spool compressor behaves like other positive displacement machines, with limitations in efficiency.  The behavior of scroll compressors, at larger geometries, suggests limitations of application of this technology. Additionally, the results lead to a hypothesis of an over-arching geometric topology that governs compression that may be optimized to further improve efficiency. To that end, the discussion is extended by introducing an entirely new positive-displacement compressor, the peristaltic compressor.  The operation of this novel compressor is introduced along with a mechanistic chamber model, validated with data from a prototype. The energy savings potential of this compressor is explored, relative to legacy compressor technologies.

 About the Speaker

Craig Bradshaw is the Director of the Center for Integrated Building Systems (CIBS) and an Associate Professor of Mechanical and Aerospace Engineering at Oklahoma State University (OSU). He earned his BSME and PhD from Purdue University in 2007 and 2012, respectively. Prior to joining the faculty at OSU, he was the Manager of Research and Development at Torad Engineering from 2012-2016. At Oklahoma State, Dr. Bradshaw founded the industry/university cooperative research center, CIBS, in 2020 and continues as its director. Dr. Bradshaw has expertise in compressor modeling and development for heat pump, air-conditioning, refrigeration, waste-heat recovery and industrial air applications. His work has led to over 80 publications and 4 patents.

Host: Professor Nenad Miljkovic 

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