Article Heat recovery and heating system for liquid-cooled data center: Energy, economic, and environmental analysis

With the rapid growth of data centers driven by information technology development, a significant amount of waste heat generated by cooling systems is currently not effectively utilized and is often discarded. Recovering this waste heat is therefore of great importance for improving overall energy efficiency and promoting low-carbon operation. In this study, we simulate a cold plate liquid cooling system integrated with a waste heat recovery unit that utilizes different natural cooling sources, taking into account real-time fluctuations in thermal load demand.

The results show that, compared with conventional liquid-cooling systems without heat recovery, the proposed configurations reduce cooling system power consumption by approximately 20–30% across all operating conditions. The minimum partial Power Usage Effectiveness (pPUE) reaches 1.13, indicating a highly efficient cooling subsystem. Moreover, up to 23% of the energy consumed in the data center can be effectively reused when temperature constraints of the heat user are considered.

From an economic perspective, selling the recovered heat for domestic hot water production can reduce the annual operating cost of the liquid-cooling system by approximately ¥200,000, resulting in a short payback period. From an environmental perspective, the waste heat recovery system significantly supports low-carbon heating, reducing carbon emissions by about 110 tCO2 per year compared with conventional gas boilers and air-source heat pumps. Overall, this study demonstrates that liquid-cooled data centers can serve as reliable and economically attractive heat sources under realistic dynamic operating conditions, providing practical guidance for large-scale waste heat recovery deployment.