Experimental analysis of a cross flow indirect evaporative cooling system

Abstract Indirect evaporative cooling is an effective way to increase energy efficiency of air conditioning systems. This technology is particularly suitable for data centers applications, where the indoor temperature can be higher than the one adopted in residential and commercial buildings. In this work an indirect evaporative cooling system based on a cross flow heat exchanger has been widely tested. The system has been designed in order to minimize water consumption, with water mass flow rate between 0.4% and 4% of the secondary air one. On the whole, 112 experiments have been carried out in different working conditions of data centers. The effects of variation of water flow rate, humidification nozzles setup and secondary air temperature, humidity and flow rate have been widely investigated. Results put in evidence that performance is slightly dependent on nozzles number and size but it is strongly influenced by the water flow rate. In addition, nozzles in counter flow arrangement perform better than in parallel flow configuration. Depending on working conditions and equipment setup, the wet bulb effectiveness varies between 50% and 85%.

[1]  Eloy Velasco Gómez,et al.  Experimental characterisation of an indirect evaporative cooling prototype in two operating modes , 2012 .

[2]  E. Iso,et al.  Measurement Uncertainty and Probability: Guide to the Expression of Uncertainty in Measurement , 1995 .

[3]  Sergey Bolotin,et al.  Comparative analysis of the cross-flow indirect evaporative air coolers , 2015 .

[4]  Kuei-Peng Lee,et al.  Analysis of energy saving potential of air-side free cooling for data centers in worldwide climate zones , 2013 .

[5]  Shahram Delfani,et al.  Energy saving potential of an indirect evaporative cooler as a pre-cooling unit for mechanical cooling systems in Iran , 2010 .

[6]  Ala Hasan,et al.  Indirect evaporative cooling : Past, present and future potentials , 2012 .

[7]  Frank Bruno,et al.  On-site experimental testing of a novel dew point evaporative cooler , 2011 .

[8]  Wasim Saman,et al.  An experimental study of a cross-flow type plate heat exchanger for dehumidification/cooling , 2002 .

[9]  F. C. R. Martínez,et al.  Comparative study of two different evaporative systems: an indirect evaporative cooler and a semi-indirect ceramic evaporative cooler , 2004 .

[10]  Gerard F. Jones,et al.  A review of data center cooling technology, operating conditions and the corresponding low-grade waste heat recovery opportunities , 2014 .

[11]  Shailesh Kumar,et al.  An experimental study of a novel dew point evaporative cooling system , 2010 .

[12]  Shahram Delfani,et al.  Experimental investigation of two-stage indirect/direct evaporative cooling system in various climatic conditions , 2009 .

[13]  Sergey Anisimov,et al.  Performance investigation of a M (Maisotsenko)-cycle cross-flow heat exchanger used for indirect evaporative cooling , 2014 .

[14]  Donal Finn,et al.  Indirect evaporative cooling potential in air-water systems in temperate climates , 2003 .

[15]  Stefano De Antonellis,et al.  Desiccant wheels for air humidification: An experimental and numerical analysis , 2015 .

[16]  Luai M. Al-Hadhrami,et al.  Performance evaluation of an indirect evaporative cooler under controlled environmental conditions , 2013 .

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

[18]  Stefano De Antonellis,et al.  Desiccant wheels effectiveness parameters: Correlations based on experimental data , 2015 .

[19]  Jaume Salom,et al.  Energy efficiency and renewable energy integration in data centres. Strategies and modelling review , 2015 .

[20]  Jae-Weon Jeong,et al.  Experimental study on the heat exchange effectiveness of a dry coil indirect evaporation cooler under various operating conditions , 2011 .

[21]  Robert J. Moffat,et al.  Describing the Uncertainties in Experimental Results , 1988 .

[22]  Ana Tejero-González,et al.  Influence of constructive parameters on the performance of two indirect evaporative cooler prototypes , 2013 .

[23]  Zhang Hainan,et al.  Free cooling of data centers: A review , 2014 .