The design and construction of a bench-top Organic Rankine Cycle for data center applications

The growing demand for data center utilization and the resulting increases in energy requirements are creating significant challenges for data center operators and for thermal designers. Design options which can cool the servers efficiently while also reducing electricity usage are thus of considerable interest. One potential technique is the use of Organic Rankine Cycle (ORC) technology which can absorb the server heat into an organic fluid and then use this heat in a power cycle to create electricity. The ORC has been found to match well with data center requirements and this paper presents the analysis of an ORC system matched with data center operating conditions and the design of an ORC test bed. The ORC test bed is designed for 20kW of waste heat collected from 2 full racks. The complete design includes the ORC power cycle and one secondary cycle as heat source. Component selection has been carefully studied in each of the two cycles. The main goals of this investigation are the steady-state characterization of an ORC under different data center operating conditions and the design of a test bed which will prove out the concept of mating ORC with data center conditions for potential customers who are seeking alternatives for data center waste heat recovery.