Performance modeling and advanced exergy analysis for low-energy consumption data center with waste heat recovery, flexible cooling and hydrogen energy

With the rapidly development of information service and artificial intelligence technology, the demand for data centers has dramatically increased, resulting in an increase of energy consumption and carbon emissions. This study proposed a power and cooling combined system with waste heat recovery, flexible cooling and hydrogen energy utilization used in data center to achieve the carbon peak and carbon neutralization. The integrated system mainly included the low temperature-proton exchange membrane fuel cell (LT-PEMFC) and the halfeffect absorption refrigeration system (HE-ABS). The lower-grade heat discharged from LT-PEMFC was utilized by HE-ABS system to provide the cooling power. The performance modeling and advanced exergy analysis of the combined system were carried out. It was showed that the total exergy efficiency of the integrated system achieved 60.55 % and the exergy efficiency of LT-PEMFC subsystem was increased by 9.78 % due to the waste heat recovery of LT-PEMFC. In order to investigate the improvement potential and the interaction between subsystems, the advanced exergy analysis of the combined systems was conducted. The results showed that the avoidable exergy destruction of high-pressure absorber and low-pressure absorber of HE-ABS accounted for 80.9 % and 68.95 % of the total exergy destruction of components, respectively. The endogenous exergy destruction of the PEMFC was greater than its exogenic exergy destruction, which indicated that the exergy destruction of PEMFC was caused by its irreversibility. The parameter analysis showed, as the operating temperature of LT-PEMFC was increased, the exergy efficiency of PEMFC first increased and then decreased, and the maximum exergy efficiency of PEMFC achieved 70.44 % when the operating temperature of LT-PEMFC was 363 K.