Optimal Piping Design for Enhanced Energy Saving in District Cooling System – A Case Study
This study performs a numerical investigation into the power consumption characteristics of various primary-secondary chilled water circuit designs in a district cooling system (DCS) installed in six buildings located within the same block in Taipei, Taiwan. An E20-II model is created of the DCS and a series of simulations are performed to determine the primary-secondary chilled water piping design which maximizes the energy saving obtained in the DCS over the course of a typical year. It is shown that the use of a region-pumping system or a boost-pumping system reduces the power consumption of the secondary chilled water circuit by 26.5% and 29.9%, respectively, compared to that of a common-pumping system. In addition, the results show that for a practical chilled water system in which the temperature differential on the primary side is 5.0oC while that on the secondary side is 6.5oC, an average monthly energy saving of around 5~7% is obtained compared to a DCS with equal temperature differentials in the primary-secondary circuits provided that the flow rate and the temperature differential of the chilled water in the primary circuit are a little less than those in the secondary circuit.
Hao Zhang, Yang Fu and Zhong Tang
C. Y. Lee et al., "Optimal Piping Design for Enhanced Energy Saving in District Cooling System – A Case Study", Advanced Materials Research, Vols. 354-355, pp. 744-752, 2012