Online robust control of chilled water systems of buildings for energy performance enhancement

Dian Ce Gao, Shengwei Wang, Fu Xiao

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review


This paper presents two enhanced robust control strategies for building chilled water systems in order to enhance their overall energy performances. A fault-tolerant control strategy for secondary chilled water pumps is proposed to avoid the low temperature difference syndrome and deficit flow problem. This strategy employs the flow-limiting technique that can ensure the water flow of secondary loop not exceed that of the primary loop while still maintaining highest possible delivery capacity of cooling to terminals. This paper also presents an adaptive optimal control strategy for complex chilled water systems involving intermediate heat exchangers. This optimal control strategy determines the optimal settings of the heat exchanger outlet water temperature (hot side) and the required operating number of heat exchangers and pumps in order to minimize the total energy consumption of pumps under varying working conditions. Results show that both of the two strategies have enhanced control robustness and reliability, particularly in avoiding deficit flow problem. Significant energy of chilled water pumps is saved when compared with conventional methods.
Original languageEnglish
Title of host publication6th Asian Conference on Refrigeration and Air Conditioning, ACRA 2012
PublisherChinese Association of Refrigeration (CAR)
Number of pages8
ISBN (Print)9781632660152
Publication statusPublished - 1 Jan 2012
Event6th Asian Conference on Refrigeration and Air Conditioning, ACRA 2012 - Xi'an, China
Duration: 26 Aug 201228 Aug 2012


Conference6th Asian Conference on Refrigeration and Air Conditioning, ACRA 2012


  • Adaptive optimal control
  • Chilled water system
  • Deficit flow
  • Energy efficiency
  • Fault-tolerant control

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

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