Journal of Central South University

, Volume 18, Issue 2, pp 573–579 | Cite as

Optimum control strategy for all-variable speed chiller plant

  • Xiao-qiang Jiang (蒋小强)Email author
  • Wei-ding Long (龙惟定)
  • Min Li (李敏)


The optimum control strategy and the saving potential of all variable chiller plant under the conditions of changing building cooling load and cooling water supply temperature were investigated. Based on a simulation model of water source chiller plant established in dynamic transient simulation program (TRNSYS), the four-variable quadratic orthogonal regression experiments were carried out by taking cooling load, cooling water supply temperature, cooling water flow rate and chilled water flow rate as variables, and the fitting formulas expressing the relationships between the total energy consumption of chiller plant with the four selected parameters was obtained. With the SAS statistical software and MATHEMATICA mathematical software, the optimal chilled water flow rate and cooling water flow rate which result in the minimum total energy consumption were determined under continuously varying cooling load and cooling water supply temperature. With regard to a chiller plant serving an office building in Shanghai, the total energy consumptions under different control strategies were computed in terms of the forecasting function of cooling load and water source temperature. The results show that applying the optimal control strategy to the chiller plant can bring a saving of 23.27% in power compared with the corresponding conventional variable speed plant, indicating that the optimal control strategy can improve the energy efficiency of chiller plant.

Key words

chiller plant control strategy variable speed cooling water flow rate chilled water flow rate 


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Copyright information

© Central South University Press and Springer-Verlag Berlin Heidelberg 2011

Authors and Affiliations

  • Xiao-qiang Jiang (蒋小强)
    • 1
    • 2
    Email author
  • Wei-ding Long (龙惟定)
    • 3
  • Min Li (李敏)
    • 1
  1. 1.College of EngineeringGuangdong Ocean UniversityZhanjiangChina
  2. 2.College of Mechanical EngineeringTongji UniversityShanghaiChina
  3. 3.Sino-German School of Applied SciencesTongji UniversityShanghaiChina

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