Effects of discharge recirculation in cooling towers on energy efficiency and visible plume potential of chilling plants

Gaoming Ge, Fu Xiao, Shengwei Wang, Liang Pu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

11 Citations (Scopus)


Due to limited space and/or improper placement of evaporative cooling towers, discharge recirculation likely occurs in practical applications. The air recirculation may adversely affect energy efficiency of the chilling plants and increase the potential of visible plume around the towers. In this study, the amount of recirculation in a counter-flow cooling tower is evaluated by computational fluid dynamics (CFD) simulation tests under different enclosure structures and crosswind conditions. Then the effects of recirculation in cooling towers on energy performance of a chilling plant and plume potential are investigated. The evaluation is conducted on a dynamic simulation platform using the weather data in a typical meteorological year of Hong Kong. Results show that crosswind can enhance recirculation in cooling towers under lower air flow rate conditions. The recirculation ratio can reach up to 15%. Results also reveal that air recirculation in cooling towers could result in the increase of overall chilling plant energy consumption by over 1.5%. The recirculation also results in significant increase of plume occurrence frequency, particularly in spring season.
Original languageEnglish
Pages (from-to)37-44
Number of pages8
JournalApplied Thermal Engineering
Publication statusPublished - 1 Jun 2012


  • Control strategy
  • Energy efficiency
  • Evaporative cooling tower
  • Recirculation
  • Visible plume

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Industrial and Manufacturing Engineering

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