Experimental analysis of a novel cooling system driven by liquid refrigerant pump and vapor compressor

• A novel energy saving cooling system driven by a liquid refrigerant pump and vapor compressor is proposed.
• The energy efficiency ratio can be improved significantly compared with traditional compression cycle system.
• Its performances and energy saving under various shift temperature are discussed.
• The proposed novel cycle shows strong energy saving potential for its application in green data center.

This study introduced a novel energy saving cooling system, i.e. a combined cycle coupled with a traditional vapor compression cycle with a pumped liquid two-phase cooling cycle. The system has two operation modes, i.e. the compression cycle mode driven by compressor and the pump cycle mode driven by refrigerant pump. A multi-purpose test bench was constructed to experimentally evaluate the performance of the integrated cycle system under various operation conditions. The effects of cycle working condition and the shift temperature between the two operation modes on the overall cycle performance were investigated in detail. It is found that the novel cycle system has a higher EER compared to the traditional compressor system when the ambient temperature is relatively low. The further experimental results and comparative annual energy saving analysis also indicated that the proper shift temperature is about −5 °C from the system EER and cooling capacity point of view.