Study on energy-saving effect of a separate radiative cooling-air conditioning hybrid refrigeration system

To reduce energy consumption of air conditioning (AC) in buildings, a novel dynamic control-based hybrid refrigeration system is proposed by combining traditional high-energy-consumption AC and zero-energy-consumption radiative cooling (RC). This system leverages the zero-energy-consumption property of RC, and assists AC to cool the building to reduce the energy consumption of refrigeration. First, the RC-AC hybrid refrigeration system with constant flow rate of working fluid is applied to a small building. Secondly, a control experiment is conducted in the room with and without RC cycle to verify the energy-saving effect. Finally, a dynamic control device for working flow status is added to avoid the reverse heating effect caused by the RC due to the fluctuation of the environment. The system consists two separate circulation circuits, one for AC and the other for RC, to reduce its complexity and design and installation cost. Compared with the AC only system, the hybrid set up achieves a nearly 15. 0% energy-saving effect of AC. It further achieves an energy-saving of about 19. 1% . This system demonstrates the energy-saving benefits of RC, and provides a reference for its further development and application. © 2024 Southeast University. All rights reserved.