A New Two-Phase Multiplier for Flow Pressure Drop in Multiport Minichannel Condensers and Evaporators

Abstract

Due to flow maldistribution, the condensation and evaporation flow patterns in multiport minichannels are considerably different from single minichannels or macrochannels. This article compiled the friction pressure drop data from experimental phase-change investigations in multiport minichannel condensers and evaporators over the past two decades. The data was reduced to friction pressure gradients, and a new two-phase multiplier was proposed for estimating the phase-change pressure drop in multiport condensers and evaporators. Thirteen hundred and forty-four condensation pressure drop and six hundred and twenty-three evaporation pressure drop data from twenty-nine studies were correlated to yield four predictive two-phase multiplier equations in the laminar and turbulent flow regimes. The predictive correlations fit 67% of the laminar condensation and 80% of the turbulent pressure drop data within ±50%. Further, 57% of the laminar evaporation and 100% of the turbulent evaporation pressure drop data were fit within ±50%. The correlations were compared with widely published correlations and were a significant improvement. Meta-analysis revealed that multiport minichannels are most effective for reducing turbulent flow condensation pressure drop and laminar flow evaporation pressure drop. The compiled data and presented correlations and analysis should be helpful to the process, electronics packaging, aviation, and aerospace industries designing compact, lightweight, and high-efficiency condensers, and evaporators.

Acknowledgments

The authors wish to thank the University of Pretoria and the Vellore Institute of Technology for providing the resources for conducting this research. No conflicts of interest are reported.

Additional information

Notes on contributors

Yagnavalkya Mukkamala

Yagnavalkya Mukkamala is a Professor of Mechanical Engineering at Vellore Institute of Technology, India. He received his Ph.D. in Mechanical Engineering from the same institute in 2008 and M.S. in Mechanical Engineering from Virginia Polytechnic Institute and State University, USA in 1993. He has published over fourteen articles in various peer-reviewed journals and numerous peer-reviewed conference articles. He has completed several funded projects as a principal investigator for the Government of India and numerous as a student investigator for the US Department of Energy and NASA. He has been cited over a hundred seventy times and has an h-index over seven. His research interests include enhanced heat transfer, the design of enhanced heat exchangers, and automotive aerodynamics.

Jaco Dirker

Jaco Dirker is an Associate Professor in Mechanical Engineering at the University of Pretoria. He received his Ph.D. from Rand Afrikaans University (University of Johannesburg) in 2004. He has published over 40 articles in peer-reviewed journals and 40 peer-reviewed conference articles. He has completed over five research projects, with the most recent project being funded by the Royal Society of the United Kingdom for over R 9 million (South African Rand). He is clean energy and enhanced heat transfer specialist and has supervised several doctoral theses and post-doctoral scholars. He is a registered professional engineer at the Engineering Council of South Africa.