Optimization criteria for the performance of heat and mass transfer in indirect evaporative cooling systems

The wide application of evaporative cooling techniques in which the optimization criteria form the theoretical basis for improving evaporative cooling performance is essential for energy conservation and emission reduction. Based on exergy analysis and the entransy dissipation-based thermal resistance method, this contribution aims to investigate the effects of flow and area distributions in the optimization of the performance of indirect evaporative cooling systems. We first establish the relationships of exergy efficiency, entransy dissipation-based thermal resistance and cooling capacity of a typical indirect cooling system. Using the prescribed inlet parameters, the heat and mass transfer coefficients and the circulating water mass flow rate, we then numerically validate that when the cooling capacity reaches a maximum, the entransy dissipation-based thermal resistance falls to a minimum while the exergy efficiency is not at an extreme value. The result shows that the entransy dissipation-based thermal resistance, not the exergy efficiency, characterizes the heat transfer performance of an evaporative cooling system, which provides a more suitable method for evaluating and analyzing the indirect cooling system.

[1]  J. Yellott,et al.  Investigation of a plate-type indirect evaporative cooling system for residences in hot and arid climates , 1987 .

[2]  J. R. Watt.  Nationwide evaporative cooling is here , 1987 .

[3]  M. S. Sodha,et al.  Recent research on an indirect evaporative cooler (IEC). Part 1: Optimization of the COP , 1997 .

[4]  M. S. Sodha,et al.  Recent research on an indirect evaporative cooler. Part VI: Evolution of design pattern for indirect evaporative cooler , 1999 .

[5]  Ruzhu Wang,et al.  Use of liquid desiccant cooling to improve the performance of vapor compression air conditioning , 2001 .

[6]  Li Nianping,et al.  Principles of exergy analysis in HVAC and evaluation of evaporative cooling schemes , 2002 .

[7]  FAISAL AL-JUWAYHEL,et al.  Experimental Evaluation of One, Two, and Three Stage Evaporative Cooling Systems , 2004 .

[8]  Somchai Wongwises,et al.  AN EXERGY ANALYSIS ON THE PERFORMANCE OF A COUNTERFLOW WET COOLING TOWER , 2007 .

[9]  Qun Chen,et al.  Field synergy equation for turbulent heat transfer and its application , 2007 .

[10]  XinGang Liang,et al.  Entransy—A physical quantity describing heat transfer ability , 2007 .

[11]  Somchai Wongwises,et al.  Effects of inlet relative humidity and inlet temperature on the performance of counterflow wet cooling tower based on exergy analysis , 2008 .

[12]  M. Boumaza,et al.  Experimental analysis of heat and mass transfer phenomena in a direct contact evaporative cooling tower , 2009 .

[13]  Qun Chen,et al.  The extremum principle of mass entransy dissipation and its application to decontamination ventilation designs in space station cabins , 2009 .

[14]  Ning Pan,et al.  A new approach to analysis and optimization of evaporative cooling system I: Theory , 2010 .

[15]  Fengrui Sun,et al.  Entransy dissipation minimization for liquid-solid phase change processes , 2010 .

[16]  Qun Chen,et al.  Moisture transfer resistance method for liquid desiccant dehumidification analysis and optimization , 2010 .

[17]  Ning Pan,et al.  A comparison of optimization theories for energy conservation in heat exchanger groups , 2011 .

[18]  Mingtian Xu,et al.  Entransy dissipation minimization for optimization of heat exchanger design , 2011 .

[19]  XueTao Cheng,et al.  Entransy flux of thermal radiation and its application to enclosures with opaque surfaces , 2011 .

[20]  L. Xie,et al.  Erosion of the prismatic layer by the organic matrix during the formation of the nacre-prism transition layer in the shell of Pinctada fucata (Bivalvia, Mollusca) , 2011 .