A review of challenging issues in the integration of absorption refrigeration and organic Rankine Cycle into a data center cooling system

Our theoretical studies showed that absorption refrigeration (AR) system and organic Rankine cycle (ORC) are the most promising technology candidates in utilizing the waste heat dissipated by data centers. Since both candidates work with heat of temperatures not less than ~65°C, this study is limited to water-cooled and hybrid two-phase cooled data centers. However, there exist challenges in the integration of these technologies into the data center design. The first issue is the scale at which the waste heat is extracted and recovered. Although the range of this scale can be from a single server to multiple racks, heat input of equipment required by AR and ORC manufacturers is the main limitation. The second issue is the method of transporting extracted waste heat from chip to either the generator of AR or the evaporator of ORC with minimum degradation of heat quality. In this paper the major focus is on the first issue.