TY - GEN
T1 - Performance measurements of transcritical R744 system using low-complexity ejector
AU - Botticella, Francesco
AU - Liu, Zishen
AU - Elbel, Stefan
N1 - Publisher Copyright:
© 2020 International Institute of Refrigeration. All rights reserved.
PY - 2020
Y1 - 2020
N2 - CO2 is a promising refrigerant for numerous applications within the cold chain. The inherent throttling losses of the transcritical cycle can be mitigated by using two-phase ejectors. However, ejectors have yet to be successfully applied to mass-produced systems. Complex ejector designs drive product cost and reduce the likelihood of their widespread use. The focus of this paper is to systematically determine the performance trade-offs of less complex ejector designs. Various simplified motive nozzle and diffuser designs were experimentally investigated. While there are differences in ejector efficiency between the different motive nozzle designs on the order of 10 percent points, the effects on system performance (capacity and COP) are far less pronounced. That is especially true when a needle mechanism is used to control the high-side pressure. Therefore, the study demonstrates that reasonable system improvements can be achieved even with less complex ejector designs, enabling a more widespread use.
AB - CO2 is a promising refrigerant for numerous applications within the cold chain. The inherent throttling losses of the transcritical cycle can be mitigated by using two-phase ejectors. However, ejectors have yet to be successfully applied to mass-produced systems. Complex ejector designs drive product cost and reduce the likelihood of their widespread use. The focus of this paper is to systematically determine the performance trade-offs of less complex ejector designs. Various simplified motive nozzle and diffuser designs were experimentally investigated. While there are differences in ejector efficiency between the different motive nozzle designs on the order of 10 percent points, the effects on system performance (capacity and COP) are far less pronounced. That is especially true when a needle mechanism is used to control the high-side pressure. Therefore, the study demonstrates that reasonable system improvements can be achieved even with less complex ejector designs, enabling a more widespread use.
KW - Capacity and COP
KW - Carbon Dioxide (CO, R744)
KW - Ejector
KW - Ejector Efficiency
KW - Low-cost Design
KW - Performance Trade-offs
UR - http://www.scopus.com/inward/record.url?scp=85098117418&partnerID=8YFLogxK
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U2 - 10.18462/iir.iccc.2020.292574
DO - 10.18462/iir.iccc.2020.292574
M3 - Conference contribution
AN - SCOPUS:85098117418
T3 - Refrigeration Science and Technology
SP - 189
EP - 196
BT - 6th IIR Conference on Sustainability and the Cold Chain, ICCC 2020 - Proceedings
PB - International Institute of Refrigeration
T2 - 6th IIR Conference on Sustainability and the Cold Chain, ICCC 2020
Y2 - 26 August 2020 through 28 August 2020
ER -