Modeling and optimization for the smart operation of a central chilled water system in a high-rise building

Abstract

Besides meeting the cooling demands of each terminal space in a high-rise building, the smart operation of a central chilled water system is also aiming at saving more electricity. Hence, it is the key issue to distribute proper amount of chilled water to each room according to its cooling load variations, i.e. achieve hydraulic balance in the chilled water network. To save electricity consumption of both chillers and circulation pumps in operation, in this paper, a supervisory optimization model is proposed for a general chilled water system. An improved node method is also presented to simulate the hydraulic behavior of the general chilled water pipe network, which is particularly adapted for a high-rise building with faster computation speed and fine accuracy. Then the proposed model is validated in a real high-rise hotel in Shanghai. In the case study, comparing with conventional operation method (On/Off or PID control), the proposed smart operation method can save 15.4-29.3% of electricity for the chilled water system in the typical days of cooling season.