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• 2017

  Measurement of heat transfer coefficient and pressure drop during evaporation of R134a in new type facility with one pass flow through microchannel tube

  Li, H. & Hrnjak, P., Jan 1 2017, In: International Journal of Heat and Mass Transfer. 115, p. 502-512 11 p.

  Research output: Contribution to journal › Article › peer-review

  • pressure drop
  • Microchannels
  • heat transfer coefficients
  • microchannels
  • Evaporation
• 2019

  Numerical study of steam condensation inside a long inclined flattened channel

  Abadi, S. M. A. N. R., Davies, W. A., Hrnjak, P. & Meyer, J. P., May 2019, In: International Journal of Heat and Mass Transfer. 134, p. 450-467 18 p.

  Research output: Contribution to journal › Article › peer-review

  • Steam
  • steam
  • Condensation
  • condensation
  • Cooling
• 2020

  Local heat transfer coefficient during stratified flow in large, flattened-tube steam condensers with non-uniform heat flux and wall temperature

  Davies, W. A. & Hrnjak, P., Jan 2020, In: International Journal of Heat and Mass Transfer. 146, 118854.

  Research output: Contribution to journal › Article › peer-review

  • Condenser tubes
  • stratified flow
  • condensers
  • wall temperature
  • heat transfer coefficients
• 2019

  Analysis and quantification of generated bubbles for flow boiling through diabatic visualization

  Yang, C. M. & Hrnjak, P., Jan 1 2019, ICR 2019 - 25th IIR International Congress of Refrigeration. Minea, V. (ed.). International Institute of Refrigeration, p. 1239-1245 7 p. 858. (Refrigeration Science and Technology; vol. 2019-August).

  Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

  • Boiling liquids
  • boiling
  • heat transfer
  • Visualization
  • bubbles
• 2020

  Nouvelle cartographie de la configuration d'écoulement pour l'ébullition de R410A en écoulement dans des tubes horizontaux à micro-ailettes tenant compte de l'effet de l'angle d'hélice

  Yang, C. M. & Hrnjak, P., Jan 2020, In: International Journal of Refrigeration. 109, p. 154-160 7 p.

  Research output: Contribution to journal › Article › peer-review

  • Boiling liquids
  • Flow patterns
  • Vapors
  • Mass transfer
  • Visualization
• 2018

  Method for evaluating the effect of inclination on the performance of large flattened-tube steam condensers with visualization of flow regimes

  Davies, W. A., Kang, Y., Hrnjak, P. & Jacobi, A. M., Jun 25 2018, In: Applied Thermal Engineering. 138, p. 934-941 8 p.

  Research output: Contribution to journal › Article › peer-review

  • Condenser tubes
  • Visualization
  • Heat transfer
  • Steam
  • Void fraction
• 2020

  Improvement of capacity and COP through use of two-stage compressor in transcritical R744 systems

  Elbel, S. & Hrnjak, P., 2020, IIR Rankine 2020 International Conference - Advances in Cooling, Heating and Power Generation, Rankine 2020. International Institute of Refrigeration, p. 157-164 8 p. (Refrigeration Science and Technology; vol. 2020-July).

  Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

  • compressors
  • Compressors
  • gas cooling
  • heat sinks
  • suction
• 2019

  Experimental investigations of the single-phase flow distribution in brazed plate heat exchangers and its impact on the heat exchanger

  Li, W. & Hrnjak, P., Jan 1 2019, ICR 2019 - 25th IIR International Congress of Refrigeration. Minea, V. (ed.). International Institute of Refrigeration, p. 2746-2753 8 p. 1564. (Refrigeration Science and Technology; vol. 2019-August).

  Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

  • single-phase flow
  • heat exchangers
  • Heat exchangers
  • flow distribution
  • headers
• 2018

  Visualisation et quantification de la séparation de l’écoulement diphasique liquide-vapeur dans un collecteur vertical à faible qualité d'entrée

  Li, J. & Hrnjak, P., Jan 2018, In: International Journal of Refrigeration. 85, p. 144-156 13 p.

  Research output: Contribution to journal › Article › peer-review

  • Two phase flow
  • Vapors
  • Visualization
  • Liquids
  • Microchannels

• Application of Intermediate Vapor Bypass to Mobile Heat Pump System: Extending Operating Range to Lower Ambient Temperature with Low Pressure Low GWP Fluid

  Feng, L. & Hrnjak, P., Jan 1 2018, In: SAE Technical Papers. 2018-April

  Research output: Contribution to journal › Conference article › peer-review

  • Heat pump systems
  • Vapors
  • Heating
  • Fluids
  • Temperature
• 2017

  Efficiency Improvement by Separation of Vapor and Liquid in Condenser Headers

  Li, J. & Hrnjak, P., Jan 1 2017, In: SAE International Journal of Materials and Manufacturing. 10, 3

  Research output: Contribution to journal › Article › peer-review

  • Vapors
  • Liquids
  • Flow rate
  • Microchannels
  • Refrigerants

• Effet de l'écoulement inversé périodique sur la performance du transfert de chaleur des évaporateurs à microcanaux

  Li, H. & Hrnjak, P., Dec 2017, In: International Journal of Refrigeration. 84, p. 309-320 12 p.

  Research output: Contribution to journal › Article › peer-review

  • Heat transfer performance
  • Microchannels
  • Evaporators
  • Heat exchangers
  • Heat transfer

• Effect of inclination on heat transfer in large flattened-tube steam condensers

  Davies, W. A., Kang, Y., Hrnjak, P. & Jacobi, A. M., Jan 1 2017, Energy. American Society of Mechanical Engineers (ASME), (ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE); vol. 6).

  Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

  • Condenser tubes
  • Steam
  • Visualization
  • Heat transfer
  • Void fraction
• 2020

  Heat transfer and flow regimes during counter-flow steam condensation in flattened-tube air-cooled condensers

  Davies, W. A. & Hrnjak, P., Feb 2020, In: International Journal of Heat and Mass Transfer. 147, 118930.

  Research output: Contribution to journal › Article › peer-review

  • Steam
  • counterflow
  • condensers
  • heat transmission
  • steam
• 2017

  Régimes d'écoulement lors de la condensation dans une zone de surchauffe

  Meyer, M. & Hrnjak, P., Dec 2017, In: International Journal of Refrigeration. 84, p. 336-343 8 p.

  Research output: Contribution to journal › Article › peer-review

  • Condensation
  • Visualization
  • Flow visualization
  • Film thickness
  • Refrigerants
• 2019

  Modified flow pattern maps for flow boiling in horizontal micro-finned tubes considering the effect of helix angle

  Yang, C. M. & Hrnjak, P., Jan 1 2019, ICR 2019 - 25th IIR International Congress of Refrigeration. Minea, V. (ed.). International Institute of Refrigeration, p. 1231-1238 8 p. 857. (Refrigeration Science and Technology; vol. 2019-August).

  Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

  • Boiling liquids
  • helices
  • boiling
  • Flow patterns
  • flow distribution
• 2020

  Advanced R744 technology applied to a multi-temperature refrigerated container

  Lawrence, N., Elbel, S. & Hrnjak, P., 2020, 14th IIR Gustav-Lorentzen Conference on Natural Fluids, GL 2020 - Proceedings. International Institute of Refrigeration, p. 622-627 6 p. (Refrigeration Science and Technology; vol. 2020-December).

  Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

  • Refrigerated containers
  • containers
  • ambient temperature
  • Temperature
  • ejectors
• 2019

  Heat transfer coefficient, pressure drop, and flow visualization for some new low GWP refrigerants during evaporation in small tube

  Li, H. & Hrnjak, P., Jan 1 2019, ICR 2019 - 25th IIR International Congress of Refrigeration. Minea, V. (ed.). International Institute of Refrigeration, p. 1499-1506 8 p. 1255. (Refrigeration Science and Technology; vol. 2019-August).

  Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

  • refrigerants
  • flow visualization
  • Flow visualization
  • pressure drop
  • heat transfer coefficients
• 2021

  An experimentally validated model for microchannel condensers with separation circuitry

  Li, J. & Hrnjak, P., Jan 25 2021, In: Applied Thermal Engineering. 183, 116114.

  Research output: Contribution to journal › Article › peer-review

  • Microchannels
  • Pressure drop
  • Phase separation
  • Finite volume method
  • Fluid dynamics
• 2020

  Ammonia chiller performance enhancement by implementation of ejector overfeed cycle with brazed plate evaporator

  Lawrence, N., Elbel, S., Zheng, J., Wenzel, M. & Hrnjak, P., 2020, 14th IIR Gustav-Lorentzen Conference on Natural Fluids, GL 2020 - Proceedings. International Institute of Refrigeration, p. 423-428 6 p. (Refrigeration Science and Technology; vol. 2020-December).

  Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

  • ejectors
  • evaporators
  • Evaporators
  • Ammonia
  • cycles
• 2019

  Flow patterns and plug/slug flow characteristic of R134a in a 0.643 mm microchannel tube

  Li, H. & Hrnjak, P., Apr 2019, In: International Journal of Heat and Mass Transfer. 132, p. 1062-1073 12 p.

  Research output: Contribution to journal › Article › peer-review

  • flow characteristics
  • plugs
  • Microchannels
  • microchannels
  • Flow patterns

• Void fraction and flow regime of in-tube condensation in a vapor-compression system

  Xiao, J. & Hrnjak, P., Jan 1 2019, ICR 2019 - 25th IIR International Congress of Refrigeration. Minea, V. (ed.). International Institute of Refrigeration, p. 1141-1149 9 p. 809. (Refrigeration Science and Technology; vol. 2019-August).

  Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

  • condensing
  • Void fraction
  • Condensation
  • Vapors
  • condensation
• 2017

  Numerical simulation of three dimensional two-phase flow and prediction of oil retention in an evaporator of the automotive air conditioning system

  Stevanovic, V. D. & Hrnjak, P., Jan 1 2017, In: Applied Thermal Engineering. 117, p. 468-480 13 p.

  Research output: Contribution to journal › Article › peer-review

  • Evaporators
  • Two phase flow
  • Air conditioning
  • Refrigerants
  • Oils

• Régulation d'un système CMA avec bipasse de gaz à évaporation instantanée, en mettant l'accent sur le démarrage et les régimes transitoires

  Li, Y. & Hrnjak, P., Dec 2017, In: International Journal of Refrigeration. 84, p. 1-12 12 p.

  Research output: Contribution to journal › Article › peer-review

  • Gases
  • Refrigerants
  • Air conditioning
  • Automobiles
  • Compressors
• 2019

  Steam condensation heat transfer coefficient in large, flattened-tube steam condensers

  Davies, W. A. & Hrnjak, P., Jan 1 2019, ICR 2019 - 25th IIR International Congress of Refrigeration. Minea, V. (ed.). International Institute of Refrigeration, p. 1263-1270 8 p. 898. (Refrigeration Science and Technology; vol. 2019-August).

  Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

  • Condenser tubes
  • condensers
  • heat transfer coefficients
  • steam
  • Condensation

• A flow regime map for condensation in macro and micro tubes with non-equilibrium effects taken into account

  Xiao, J. & Hrnjak, P., Mar 2019, In: International Journal of Heat and Mass Transfer. 130, p. 893-900 8 p.

  Research output: Contribution to journal › Article › peer-review

  • Condensation
  • Macros
  • condensation
  • tubes
  • Visualization

• Flow patterns and pressure drop of vertical upward flows in a tube with header-like protrusions with R134a

  Qian, H. & Hrnjak, P., Jan 1 2019, ICR 2019 - 25th IIR International Congress of Refrigeration. Minea, V. (ed.). International Institute of Refrigeration, p. 1223-1230 8 p. 844. (Refrigeration Science and Technology; vol. 2019-August).

  Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

  • headers
  • pressure drop
  • Flow patterns
  • mass flow rate
  • Pressure drop
• 2020

  A correlation for heat transfer coefficient during stratified steam condensation in large flattened tubes with variable inclination and wall temperature

  Davies, W. A. & Hrnjak, P., Jan 2020, In: International Journal of Heat and Mass Transfer. 146, 118666.

  Research output: Contribution to journal › Article › peer-review

  • Steam
  • wall temperature
  • heat transfer coefficients
  • steam
  • Condensation
• 2019

  Flow regimes during condensation from superheated vapor

  Xiao, J. & Hrnjak, P., Apr 2019, In: International Journal of Heat and Mass Transfer. 132, p. 301-308 8 p.

  Research output: Contribution to journal › Article › peer-review

  • Transition flow
  • Condensation
  • Vapors
  • condensation
  • vapors

• Performance evaluation on heat pump water heater with drop-in refrigerant R1234yf and condenser size modification

  Shi, C. & Hrnjak, P., Jan 1 2019, ICR 2019 - 25th IIR International Congress of Refrigeration. Minea, V. (ed.). International Institute of Refrigeration, p. 1813-1820 8 p. 1686. (Refrigeration Science and Technology; vol. 2019-August).

  Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

  • heat pumps
  • Water heaters
  • refrigerants
  • condensers
  • Refrigerants
• 2017

  Oil flow at the scroll compressor discharge: Visualization and CFD simulation

  Xu, J. & Hrnjak, P., Sep 6 2017, In: IOP Conference Series: Materials Science and Engineering. 232, 1, 012051.

  Research output: Contribution to journal › Conference article › peer-review

  • Scroll compressors
  • Discharge (fluid mechanics)
  • Oils
  • Visualization
  • Computational fluid dynamics
• 2019

  Performance evaluation and validation of a novel heat pump water heater with rotary compressor and D-shaped condenser coils

  Shi, C. & Hrnjak, P., Jan 1 2019, ICR 2019 - 25th IIR International Congress of Refrigeration. Minea, V. (ed.). International Institute of Refrigeration, p. 4389-4398 10 p. 584. (Refrigeration Science and Technology; vol. 2019-August).

  Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

  • heat pumps
  • Water heaters
  • condensers
  • compressors
  • heaters

• Effect of helical micro-fins on two-phase flow behavior of R410A evaporating in horizontal round tubes obtained through visualization

  Yang, C. M. & Hrnjak, P., Dec 2019, In: International Journal of Heat and Mass Transfer. 144, 118654.

  Research output: Contribution to journal › Article › peer-review

  • fins
  • two phase flow
  • Two phase flow
  • Visualization
  • tubes
• 2021

  Optimization of a microchannel condenser with separation circuitry

  Li, J. & Hrnjak, P., Feb 5 2021, In: Applied Thermal Engineering. 184, 116273.

  Research output: Contribution to journal › Article › peer-review

  • Microchannels
  • Velocity distribution
  • Vapors
  • Flow rate
  • Liquids
• 2019

  Séparateur d'huile par coalescence pour compresseurs

  Xu, J. & Hrnjak, P., Oct 2019, In: International Journal of Refrigeration. 106, p. 41-53 13 p.

  Research output: Contribution to journal › Article › peer-review

  • Separators
  • Compressors
  • Oils
  • Coalescence
  • Wire
• 2018

  Design and validation of a transcritical CO2 mobile refrigerated container system for military applications

  Lawrence, N., Elbel, S. & Hrnjak, P., Jan 1 2018, 13th IIR Gustav Lorentzen Conference on Natural Refrigerants: Natural Refrigerant Solutions for Warm Climate Countries, Proceedings. International Institute of Refrigeration, p. 882-890 9 p. (Refrigeration Science and Technology; vol. 2018-June).

  Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

  • Refrigerated containers
  • Military applications
  • containers
  • refrigerants
  • Refrigerants
• 2019

  Performance optimization of two-stage compressor system using transcritical R744

  Elbel, S. & Hrnjak, P., Sep 3 2019, In: IOP Conference Series: Materials Science and Engineering. 604, 1, 012034.

  Research output: Contribution to journal › Conference article › peer-review

  Open Access

  • Compressors
  • Temperature
  • Heat sinks
  • Hot Temperature
  • Gases
• 2017

  Experimentally Validated Effects of Separation of Liquid and Vapor on Performance of Condenser and System

  Li, J., Feng, L. & Hrnjak, P. S., Mar 28 2017, In: SAE Technical Papers. 2017-March, March

  Research output: Contribution to journal › Conference article › peer-review

  • Vapors
  • Liquids
  • Heat exchangers
  • Microchannels
  • Refrigerants
• 2019

  Numerical simulation of two-phase flow in the second header of MAC condenser

  Li, J. & Hrnjak, P., Apr 2 2019, In: SAE Technical Papers. 2019-April, April

  Research output: Contribution to journal › Conference article › peer-review

  • Two phase flow
  • Air conditioning
  • Phase separation
  • Vapors
  • Computer simulation
• 2017

  Refrigerant Charge Imbalance in a Mobile Reversible Air Conditioning-Heat Pump System

  Feng, L. & Hrnjak, P. S., Mar 28 2017, In: SAE Technical Papers. 2017-March, March

  Research output: Contribution to journal › Conference article › peer-review

  • Heat pump systems
  • Refrigerants
  • Air conditioning
  • Heating
  • Cooling

• Amélioration de la performance d'un condenseur par séparation de phase confirmée par étude expérimentale et par modélisation

  Li, J. & Hrnjak, P., Jun 1 2017, In: International Journal of Refrigeration. 78, p. 60-69 10 p.

  Research output: Contribution to journal › Article › peer-review

  • Phase separation
  • Heat exchangers
  • Flow rate
  • Microchannels
  • Refrigerants

• La séparation dans les condenseurs pour une efficacité accrue

  Li, J. & Hrnjak, P., Jul 1 2017, In: International Journal of Refrigeration. 79, p. 1-9 9 p.

  Research output: Contribution to journal › Article › peer-review

  • Vapors
  • Flow rate
  • Heat transfer performance
  • Microchannels
  • Refrigerants
• 2018

  Formation, distribution et circulation des gouttelettes d'huile dans le plénum de compresseur

  Xu, J. & Hrnjak, P., Sep 2018, In: International Journal of Refrigeration. 93, p. 184-194 11 p.

  Research output: Contribution to journal › Article › peer-review

  • Compressors
  • Oils
  • Fog
  • Visualization
  • Atomization

• A pressure drop model for condensation accounting for non-equilibrium effects

  Xiao, J. & Hrnjak, P., Nov 2018, In: International Journal of Heat and Mass Transfer. 126, p. 421-430 10 p.

  Research output: Contribution to journal › Article › peer-review

  • pressure drop
  • Condensation
  • Pressure drop
  • condensation
  • condensing
• 2019

  Characterization of wire mesh structure for coalescing oil separation

  Xu, J. & Hrnjak, P., Sep 3 2019, In: IOP Conference Series: Materials Science and Engineering. 604, 1, 012037.

  Research output: Contribution to journal › Conference article › peer-review

  Open Access

  • Oils
  • Characterization (materials science)
  • Wire
  • Coalescence
  • Separators
• 2020

  Visualization of R410A Flow Boiling Inside Horizontal Smooth Tubes under Diabatic Conditions

  Yang, C. M. & Hrnjak, P., 2020, (Accepted/In press) In: Heat Transfer Engineering.

  Research output: Contribution to journal › Article › peer-review

  • flow visualization
  • Boiling liquids
  • boiling
  • Vapors
  • Visualization
• 2019

  Thermo-hydraulic model for steam condensation in a large, inclined, flattened-tube air-cooled condenser

  Davies, W. A. & Hrnjak, P., Feb 25 2019, In: Applied Thermal Engineering. 149, p. 745-756 12 p.

  Research output: Contribution to journal › Article › peer-review

  • Hydraulic models
  • Condensation
  • Steam
  • Air
  • Heat transfer coefficients
• 2017

  Thermosiphon with vapor separation: Experimental comparison to conventional type

  Zhu, L. & Hrnjak, P., 2017, In: Applied Thermal Engineering. 121, p. 879-886 8 p.

  Research output: Contribution to journal › Article › peer-review

  • Thermosyphons
  • Vapors
  • Flow rate
  • Thermal load
  • Pressure drop
• 2019

  Effect of inclination on heat transfer and flow regimes in large flattened-tube steam condensers

  Davies, W. A., Kang, Y., Hrnjak, P. & Jacobi, A. M., Feb 5 2019, In: Applied Thermal Engineering. 148, p. 999-1006 8 p.

  Research output: Contribution to journal › Article › peer-review

  • Condenser tubes
  • Heat transfer
  • Steam
  • Void fraction
  • Condensation

• Effects of Airflow Profile and Condensation Pressure on Performance of Air-Cooled Condensers

  Davies, W. A. & Hrnjak, P., Jan 1 2019, (Accepted/In press) In: Heat Transfer Engineering.

  Research output: Contribution to journal › Article › peer-review

  • condensers
  • Condensation
  • condensation
  • air
  • tubes