A general three-dimensional simulation approach for micro-channel heat exchanger based on graph theory

Abstract For meeting the requirements of quickly designing high performance micro-channel heat exchanger, a general three-dimensional simulation approach considering the factors of heat conductions via fins, quality distribution among micro-channel tubes and flexible flow circuit arrangements is proposed in this paper. In the simulation approach, an approximate analytical solution for describing the three-dimensional heat conductions via fins is presented, having higher computation speed over the numerical method of directly calculating heat conductions; a theory-based refrigerant distribution model for predicting the quality distribution among micro-channel tubes is established instead of using homogeneous quality distribution, resulting in the improvement of evaporator model accuracy; and a graph-theory based computation algorithm is developed to calculate any possible flow circuit conveniently and quickly. The presented model is validated by experiments, and the deviations of the predicted heat capacity of micro-channel evaporator, condenser and gas cooler from the measured ones are within ±5%.

[1]  Vikrant Aute,et al.  CoilDesigner: a general-purpose simulation and design tool for air-to-refrigerant heat exchangers , 2006 .

[2]  Charles E. Goodremote,et al.  Compact Air Cooled Air Conditioning Condenser , 1988 .

[3]  R. Radermacher,et al.  Microchannel Heat Exchangers with Carbon Dioxide , 2001 .

[4]  V. Gnielinski.  New equations for heat and mass transfer in turbulent pipe and channel flow , 1976 .

[5]  P. Hrnjak,et al.  Periodical reverse flow and boiling fluctuations in a microchannel evaporator of an air-conditioning system , 2013 .

[6]  Yang Zou.  Performance measurement and visualization on the refrigerant distribution in the vertical manifold of the microchannel tube heat exchanger , 2010 .

[7]  Clark W. Bullard,et al.  Development of a microchannel evaporator model for a CO2 air-conditioning system , 2001 .

[8]  Chun-Lu Zhang,et al.  A general steady state mathematical model for fin-and-tube heat exchanger based on graph theory , 2004 .

[9]  Srinivas Garimella,et al.  Condensation Pressure Drop in Circular Microchannels , 2005 .

[10]  K. Gungor,et al.  A general correlation for flow boiling in tubes and annuli , 1986 .

[11]  Predrag Stojan Hrnjak,et al.  Experimentally Validated Model of Refrigerant Distribution in a Parallel Microchannel Evaporator , 2012 .

[12]  Yu Zhao,et al.  Development of a mini-channel evaporator model using R1234yf as working fluid , 2012 .

[13]  Reinhard Radermacher,et al.  Refrigerant Distribution in Minichannel Evaporator Manifolds , 2007 .

[14]  P. Hrnjak,et al.  R-744 gas cooler model development and validation , 2001 .

[15]  C. Oliet,et al.  Two-phase flow distribution in multiple parallel tubes , 2010 .

[16]  Davide Del Col,et al.  Condensation of Halogenated Refrigerants Inside Smooth Tubes , 2002 .

[17]  F. Vera-García,et al.  Compact heat exchangers modeling: Condensation , 2010 .

[18]  Ovadia Shoham,et al.  Two-phase flow splitting in a tee junction—experiment and modelling , 1987 .

[19]  José Gonzálvez-Maciá,et al.  Numerical model for microchannel condensers and gas coolers: Part I – Model description and validation , 2013 .

[20]  Predrag Stojan Hrnjak,et al.  Flash gas bypass in mobile air conditioning system with R134a , 2012 .

[21]  Xiaohong Han,et al.  Investigating the thermal-hydraulic performance of new refrigerant mixtures through numerical simulation of minichannel and microchannel evaporators , 2013 .

[22]  Dae-Hyun Jin,et al.  Investigation on Refrigerant Distribution in Evaporator Manifolds , 2006 .

[23]  Piotr A. Domanski,et al.  Impact of classical assumptions in modelling a microchannel gas cooler , 2011 .

[24]  Armin Hafner,et al.  Development of compact heat exchangers for CO2 air-conditioning systems☆ , 1998 .

[25]  Z. Qi,et al.  Performance enhancement study of mobile air conditioning system using microchannel heat exchangers , 2010 .

[26]  Liang-Liang Shao,et al.  Numerical modeling of serpentine microchannel condensers , 2009 .

[27]  Richard T. Lahey,et al.  Phase separation in dividing two-phase flows , 1988 .

[28]  Guoliang Ding,et al.  Pressure drop during horizontal flow boiling of R410A/oil mixture in 5 mm and 3 mm smooth tubes , 2009 .

[29]  Chi-Chuan Wang,et al.  A generalized heat transfer correlation for Iouver fin geometry , 1997 .

[30]  P. Hrnjak,et al.  Developing Adiabatic Two Phase Flow in Headers—Distribution Issue in Parallel Flow Microchannel Heat Exchangers , 2004 .

[31]  Brian Elmegaard,et al.  Modelling refrigerant distribution in microchannel evaporators , 2009 .

[32]  Guoliang Ding,et al.  Recent developments in simulation techniques for vapour-compression refrigeration systems , 2007 .

[33]  Predrag Stojan Hrnjak,et al.  Experimental and numerical study on microchannel and round-tube condensers in a R410A residential air-conditioning system , 2008 .

[34]  Pietro Asinari,et al.  Effects of thermal conduction in microchannel gas coolers for carbon dioxide , 2004 .

[35]  Pega Hrnjak.  Developing Adiabatic Two Phase Flow in Headers , 2003 .