Solid oxide fuel cells, absorption chillers, data centers
Thermal integration of a solid oxide fuel cell and a lithium bromide absorption chiller is proposed for air conditioning at data centers. Solid oxide fuel cells (SOFC) can be effectively implemented as primary energy producers at data centers due to their efficiency, environmental friendliness, and fuel flexibility. This study focuses on row-level SOFC power in the range of 150 – 200 kW. Operating at temperatures greater than 700°C, SOFC systems can produce high quality heat that can be utilized by absorption technology to provide supplemental cooling for the servers. This study investigates the operation of a triple-effect absorption chiller (AC) in two possible configurations of a data center. The first configuration corresponds to traditional air-cooled servers. This configuration offers row-level cooling using a large-scale triple-effect lithium-bromide absorption chiller to provide cooling using traditional air handling units. The second configuration corresponds to newer liquid cooled servers, which can use chilling at higher temperatures. The study theoretically investigated the SOFC system and the useful heat within the exhaust stream. Exercising a mathematical model, we find that SOFC exhaust temperatures range from 250-350°C. Combining the exhaust heat characterization with waste heat recovery (WHR) from a triple-effect AC, we verify that the useful heat in the exhaust ranges between 80 and 120 kW. A mathematical model of a triple-effect AC investigates the operation of the AC between the varying exhaust temperatures and chilling temperatures. We concluded that at higher chilling temperatures, the integrated SOFC/AC system can fully offset the chilling and power demand of the server row in the data center.