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The Effects of Capacity Coupling and Wet Air Return on the Energy Performance of Chiller-Cooling Tower Systems

Published online by Cambridge University Press:  07 December 2011

C.-W. Liu  and
Y.-K. Chuah
C.-W. Liu
Affiliation:
Graduate Institute of Mechanical and Electrical Engineering, National Taipei University of Technology, Taipei, Taiwan 10608, R.O.C.
Y.-K. Chuah*
Affiliation:
Department of Energy and Refrigerating Air-Conditioning Engineering, National Taipei University of Technology, Taipei, Taiwan 10608, R.O.C.
*
**Professor, Corresponding author
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Abstract

This study uses a novel concept of capacity coupling of chiller-cooling tower system to investigate the system energy performance. System performance factor (SPF) of the chiller-cooling tower system is used in the analysis. A regression function is obtained for hourly reset of condensing water temperature so to achieve maximum SPF. The regression function includes parameters such as ambient wet bulb temperature, chiller load ratio, tower capacity ratio, and a dimensionless relative efficiency of chiller and cooling tower. The regression function has an R2 close to 1 compared to the computed results. It is found that for capacity coupling ratio of 1.1 ∼ 1.6, SPF would increase by about 3 ∼ 6% compared with a typical base control. The effect of wet air return is presented as an equivalent wet bulb temperature. It has been found that SPF would decrease significantly when higher equivalent wet bulb temperature occurs at the tower inlet.

Keywords

Water chillerCooling towerCapacity couplingEnergy saving
Type
Technical Note
Information
Journal of Mechanics , Volume 27 , Issue 4 , December 2011 , pp. N25 - N31
Copyright
Copyright © The Society of Theoretical and Applied Mechanics, R.O.C. 2011

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References

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