Multiphase Mixture Simulations of a Specific Two-Phase R-744 Ejector Geometry

Baris Burak Kanbur; Alexander  Busch; Ekaterini E. Kriezi; Wiebke Brix Markussen; Martin Ryhl Kærn; Jens Honore Walther; Jóhannes  Kristófersson

doi:10.1007/978-3-031-66609-4_42

Multiphase Mixture Simulations of a Specific Two-Phase R-744 Ejector Geometry

Baris Burak Kanbur^*, Alexander Busch, Ekaterini E. Kriezi, Wiebke Brix Markussen, Martin Ryhl Kærn, Jens Honore Walther, Jóhannes Kristófersson

^*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceeding › Article in proceedings › Research › peer-review

Abstract

Carbon dioxide (R-744 or CO₂) is a so-called ‘natural refrigerant’ in vapor-compression refrigeration systems often used due to its environment-friendly properties and therefore supporting sustainability. Due to its low critical point, R-744 is often operated in transcritical conditions, which results in energy loss at the throttling stage. To counteract the energy loss, two-phase ejectors are preferred to improve the overall coefficient of performance of the system, but the understanding of the two-phase mixture inside the ejector geometry is complex from the viewpoints of multiphase turbulent mixing, transcritical expansion, and high-velocity flow profile. This study reports on Computational Fluid Dynamics (CFD) simulations for a specific two-phase R-744 ejector geometry. Four opera-tionally different cases are investigated, all of them featuring supercritical motive nozzle inlet conditions and saturated gas suction nozzle inlet conditions. The CFD study is performed in the Simcenter STAR-CCM+ CFD environment using the Two-Phase thermodynamic equilibrium model. Comparison of the results with experimental data from the litererature show that the mass entrainment ratio deviate between 3.2 % to 8.3 %. The relative errors of the motive and suction mass flow rates are in the ranges of 15.7 % to 21.7 % and 0.1 % to 12.4 %, respectively. Detailed analysis of the fields of pressure and velocity are provided.

Original language	English
Title of host publication	Proceedings of the 14th International Conference on Computational Heat and Mass Transfer
Editors	A. C. Benim, R. Bennacer, A. A. Mohamad, P. Ocłoń, SH. Suh, J. Taler
Publisher	Springer
Publication date	2024
Pages	456–465
ISBN (Print)	978-3-031-66608-7
ISBN (Electronic)	978-3-031-66609-4
DOIs	https://doi.org/10.1007/978-3-031-66609-4_42
Publication status	Published - 2024
Event	14th International Conference on Computational Heat and Mass Transfer - Düsseldorf, Germany Duration: 4 Sept 2023 → 8 Sept 2023

Conference

Conference	14th International Conference on Computational Heat and Mass Transfer
Country/Territory	Germany
City	Düsseldorf
Period	04/09/2023 → 08/09/2023

Series	Lecture Notes in Mechanical Engineering
ISSN	2195-4356

Keywords

Multiphase Mixture
Two-phase Ejector
Natural Refrigerants

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Kanbur, B. B., Busch, A., E. Kriezi, E., Markussen, W. B., Kærn, M. R., Walther, J. H., & Kristófersson, J. (2024). Multiphase Mixture Simulations of a Specific Two-Phase R-744 Ejector Geometry. In A. C. Benim, R. Bennacer, A. A. Mohamad, P. Ocłoń, SH. Suh, & J. Taler (Eds.), Proceedings of the 14th International Conference on Computational Heat and Mass Transfer (pp. 456–465). Springer. https://doi.org/10.1007/978-3-031-66609-4_42

Kanbur, Baris Burak ; Busch, Alexander ; E. Kriezi, Ekaterini et al. / Multiphase Mixture Simulations of a Specific Two-Phase R-744 Ejector Geometry. Proceedings of the 14th International Conference on Computational Heat and Mass Transfer . editor / A. C. Benim ; R. Bennacer ; A. A. Mohamad ; P. Ocłoń ; SH. Suh ; J. Taler. Springer, 2024. pp. 456–465 (Lecture Notes in Mechanical Engineering).

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title = "Multiphase Mixture Simulations of a Specific Two-Phase R-744 Ejector Geometry",

abstract = "Carbon dioxide (R-744 or CO2) is a so-called {\textquoteleft}natural refrigerant{\textquoteright} in vapor-compression refrigeration systems often used due to its environment-friendly properties and therefore supporting sustainability. Due to its low critical point, R-744 is often operated in transcritical conditions, which results in energy loss at the throttling stage. To counteract the energy loss, two-phase ejectors are preferred to improve the overall coefficient of performance of the system, but the understanding of the two-phase mixture inside the ejector geometry is complex from the viewpoints of multiphase turbulent mixing, transcritical expansion, and high-velocity flow profile. This study reports on Computational Fluid Dynamics (CFD) simulations for a specific two-phase R-744 ejector geometry. Four opera-tionally different cases are investigated, all of them featuring supercritical motive nozzle inlet conditions and saturated gas suction nozzle inlet conditions. The CFD study is performed in the Simcenter STAR-CCM+ CFD environment using the Two-Phase thermodynamic equilibrium model. Comparison of the results with experimental data from the litererature show that the mass entrainment ratio deviate between 3.2 % to 8.3 %. The relative errors of the motive and suction mass flow rates are in the ranges of 15.7 % to 21.7 % and 0.1 % to 12.4 %, respectively. Detailed analysis of the fields of pressure and velocity are provided.",

keywords = "Multiphase Mixture, Two-phase Ejector, Natural Refrigerants",

author = "Kanbur, {Baris Burak} and Alexander Busch and {E. Kriezi}, Ekaterini and Markussen, {Wiebke Brix} and K{\ae}rn, {Martin Ryhl} and Walther, {Jens Honore} and J{\'o}hannes Krist{\'o}fersson",

year = "2024",

doi = "10.1007/978-3-031-66609-4_42",

language = "English",

isbn = "978-3-031-66608-7",

series = "Lecture Notes in Mechanical Engineering",

publisher = "Springer",

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editor = "Benim, {A. C.} and R. Bennacer and Mohamad, {A. A.} and P. Oc{\l}o{\'n} and SH. Suh and Taler, {J. }",

booktitle = "Proceedings of the 14th International Conference on Computational Heat and Mass Transfer",

note = "14th International Conference on Computational Heat and Mass Transfer , ICCHMT 2023 ; Conference date: 04-09-2023 Through 08-09-2023",

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Kanbur, BB, Busch, A, E. Kriezi, E, Markussen, WB, Kærn, MR, Walther, JH & Kristófersson, J 2024, Multiphase Mixture Simulations of a Specific Two-Phase R-744 Ejector Geometry. in AC Benim, R Bennacer, AA Mohamad, P Ocłoń, SH Suh & J Taler (eds), Proceedings of the 14th International Conference on Computational Heat and Mass Transfer . Springer, Lecture Notes in Mechanical Engineering, pp. 456–465, 14th International Conference on Computational Heat and Mass Transfer , Düsseldorf, North Rhine-Westphalia, Germany, 04/09/2023. https://doi.org/10.1007/978-3-031-66609-4_42

Multiphase Mixture Simulations of a Specific Two-Phase R-744 Ejector Geometry. / Kanbur, Baris Burak; Busch, Alexander ; E. Kriezi, Ekaterini et al.
Proceedings of the 14th International Conference on Computational Heat and Mass Transfer . ed. / A. C. Benim; R. Bennacer; A. A. Mohamad; P. Ocłoń; SH. Suh; J. Taler. Springer, 2024. p. 456–465 (Lecture Notes in Mechanical Engineering).

Research output: Chapter in Book/Report/Conference proceeding › Article in proceedings › Research › peer-review

TY - GEN

T1 - Multiphase Mixture Simulations of a Specific Two-Phase R-744 Ejector Geometry

AU - Kanbur, Baris Burak

AU - Busch, Alexander

AU - E. Kriezi, Ekaterini

AU - Markussen, Wiebke Brix

AU - Kærn, Martin Ryhl

AU - Walther, Jens Honore

AU - Kristófersson, Jóhannes

PY - 2024

Y1 - 2024

N2 - Carbon dioxide (R-744 or CO2) is a so-called ‘natural refrigerant’ in vapor-compression refrigeration systems often used due to its environment-friendly properties and therefore supporting sustainability. Due to its low critical point, R-744 is often operated in transcritical conditions, which results in energy loss at the throttling stage. To counteract the energy loss, two-phase ejectors are preferred to improve the overall coefficient of performance of the system, but the understanding of the two-phase mixture inside the ejector geometry is complex from the viewpoints of multiphase turbulent mixing, transcritical expansion, and high-velocity flow profile. This study reports on Computational Fluid Dynamics (CFD) simulations for a specific two-phase R-744 ejector geometry. Four opera-tionally different cases are investigated, all of them featuring supercritical motive nozzle inlet conditions and saturated gas suction nozzle inlet conditions. The CFD study is performed in the Simcenter STAR-CCM+ CFD environment using the Two-Phase thermodynamic equilibrium model. Comparison of the results with experimental data from the litererature show that the mass entrainment ratio deviate between 3.2 % to 8.3 %. The relative errors of the motive and suction mass flow rates are in the ranges of 15.7 % to 21.7 % and 0.1 % to 12.4 %, respectively. Detailed analysis of the fields of pressure and velocity are provided.

AB - Carbon dioxide (R-744 or CO2) is a so-called ‘natural refrigerant’ in vapor-compression refrigeration systems often used due to its environment-friendly properties and therefore supporting sustainability. Due to its low critical point, R-744 is often operated in transcritical conditions, which results in energy loss at the throttling stage. To counteract the energy loss, two-phase ejectors are preferred to improve the overall coefficient of performance of the system, but the understanding of the two-phase mixture inside the ejector geometry is complex from the viewpoints of multiphase turbulent mixing, transcritical expansion, and high-velocity flow profile. This study reports on Computational Fluid Dynamics (CFD) simulations for a specific two-phase R-744 ejector geometry. Four opera-tionally different cases are investigated, all of them featuring supercritical motive nozzle inlet conditions and saturated gas suction nozzle inlet conditions. The CFD study is performed in the Simcenter STAR-CCM+ CFD environment using the Two-Phase thermodynamic equilibrium model. Comparison of the results with experimental data from the litererature show that the mass entrainment ratio deviate between 3.2 % to 8.3 %. The relative errors of the motive and suction mass flow rates are in the ranges of 15.7 % to 21.7 % and 0.1 % to 12.4 %, respectively. Detailed analysis of the fields of pressure and velocity are provided.

KW - Multiphase Mixture

KW - Two-phase Ejector

KW - Natural Refrigerants

U2 - 10.1007/978-3-031-66609-4_42

DO - 10.1007/978-3-031-66609-4_42

M3 - Article in proceedings

SN - 978-3-031-66608-7

T3 - Lecture Notes in Mechanical Engineering

SP - 456

EP - 465

BT - Proceedings of the 14th International Conference on Computational Heat and Mass Transfer

A2 - Benim, A. C.

A2 - Bennacer, R.

A2 - Mohamad, A. A.

A2 - Ocłoń, P.

A2 - Suh, SH.

A2 - Taler, J.

PB - Springer

T2 - 14th International Conference on Computational Heat and Mass Transfer

Y2 - 4 September 2023 through 8 September 2023

ER -

Kanbur BB, Busch A, E. Kriezi E, Markussen WB, Kærn MR, Walther JH et al. Multiphase Mixture Simulations of a Specific Two-Phase R-744 Ejector Geometry. In Benim AC, Bennacer R, Mohamad AA, Ocłoń P, Suh SH, Taler J, editors, Proceedings of the 14th International Conference on Computational Heat and Mass Transfer . Springer. 2024. p. 456–465. (Lecture Notes in Mechanical Engineering). doi: 10.1007/978-3-031-66609-4_42

Multiphase Mixture Simulations of a Specific Two-Phase R-744 Ejector Geometry

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