Pega Hrnjak

Best Publications

• Experimental validation of a prototype ejector designed to reduce throttling losses encountered in transcritical R744 system operation

  Stefan Elbel;Pega Hrnjak

  550
  Citations

• Frost, defrost, and refrost and its impact on the air-side thermal-hydraulic performance of louvered-fin, flat-tube heat exchangers

  Y. Xia;Y. Zhong;P.S. Hrnjak;A.M. Jacobi

  214
  Citations

• R-744 gas cooler model development and validation

  Jian Min Yin;Clark W. Bullard;Predrag S. Hrnjak

  193
  Citations

• CO2 and R410A flow boiling heat transfer, pressure drop, and flow pattern at low temperatures in a horizontal smooth tube

  C.Y. Park;P.S. Hrnjak

  189
  Citations

• Experimental and numerical study on microchannel and round-tube condensers in a R410A residential air-conditioning system

  Chang Yong Park;Pega Hrnjak

  147
  Citations

• Single phase pressure drop in microchannels

  Predrag Stojan Hrnjak;Xiao Tu

  137
  Citations

• Flash gas bypass for improving the performance of transcritical R744 systems that use microchannel evaporators

  Stefan Elbel;Predrag Stojan Hrnjak

  129
  Citations

• Contribution of Internal Heat Exchanger to Transcritical R-744 Cycle Performance

  D. E. Boewe;C. W. Bullard;J. M. Yin;P. S. Hrnjak

  126
  Citations

• Microchannel heat exchangers for charge minimization in air-cooled ammonia condensers and chillers

  Pega Hrnjak;Andy D. Litch

  121
  Citations

• Flash gas bypass in mobile air conditioning system with R134a

  Hanfei Tuo;Predrag Stojan Hrnjak

  119
  Citations

• Experimental results of transcritical CO2 heat pump for residential application

  M. R. Richter;S. M. Song;J. M. Yin;M. H. Kim

  109
  Citations

• Experimental investigation on two-phase flow boiling heat transfer of five refrigerants in horizontal small tubes of 0.5, 1.5 and 3.0 mm inner diameters

  Jong Taek Oh;Agus Sunjarianto Pamitran;Kwang Il Choi;Pega Hrnjak

  108
  Citations

• CO2 flow condensation heat transfer and pressure drop in multi-port microchannels at low temperatures

  Chang Yong Park;Predrag Stojan Hrnjak

  106
  Citations

• Effect of the header pressure drop induced flow maldistribution on the microchannel evaporator performance

  Hanfei Tuo;Predrag Stojan Hrnjak;Predrag Stojan Hrnjak

  103
  Citations

• Effect of the condenser subcooling on the performance of vapor compression systems

  Gustavo Pottker;Predrag Stojan Hrnjak

  103
  Citations

• Characteristics of two-phase flow pattern transitions and pressure drop of five refrigerants in horizontal circular small tubes

  Agus Sunjarianto Pamitran;Kwang Il Choi;Jong Taek Oh;Pega Hrnjak

  98
  Citations

• Experiment and visualization on R134a upward flow in the vertical header of microchannel heat exchanger and its effect on distribution

  Yang Zou;Predrag Stojan Hrnjak;Predrag Stojan Hrnjak

  95
  Citations

• Experimental investigation of the effect of condenser subcooling in R134a and R1234yf air-conditioning systems with and without internal heat exchanger

  Gustavo Pottker;Pega Hrnjak

  94
  Citations

• Air-side performance evaluation of three types of heat exchangers in dry, wet and periodic frosting conditions

  Ping Zhang;Ping Zhang;Predrag Stojan Hrnjak

  89
  Citations

• Ejector Refrigeration: An Overview of Historical and Present Developments with an Emphasis on Air-Conditioning Applications

  Stefan Elbel;Predrag Hrnjak

  87
  Citations