Thermal management and heat transfer enhancement in air conditioning systems with chillers through smart control of chilled water backup systems

Air conditioning systems are significant contributors to electricity consumption in building operations, making thermal management and energy efficiency critical. This study focuses on enhancing the thermal performance and heat transfer efficiency of the chilled water system by implementing smart control of variable frequency chillers during low-load operations. Monthly cumulative cooling capacities and chilled water circulation data were analyzed, selecting January, February, March, November, and December for nighttime low-load energy-saving experiments. Regression models for each chiller were established, using indices such as R², P-value, YIF, and average error rate of Y-values to validate the performance equations. Results demonstrated a significant positive correlation between load rate and chiller efficiency. During the selected months, operational data revealed efficiency improvements and energy-saving cumulative effects. The findings indicate that employing the chilled water interconnection pipeline system for load transfer increases chiller load rates, enhancing overall system efficiency and reducing the total power consumption of auxiliary equipment. The total energy saved during the operation amounted to 607,738 kWh, leading to a reduction in carbon emissions of 257,681 kg-CO₂, equivalent to the annual carbon sequestration of Daan Forest Park (approximately 110.5–242.6 metric tons).