Here is the abstract you requested from the thermal_2015 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Critical Non-Thermal Factors for Oil Immersion Cooled Data Center|
|Keywords: Oil Immersion Cooled Data Centers, Dielectric Mineral Oil, Material Properties|
|Full submersion of servers in dielectric oils offers an opportunity for significant cooling energy savings and increased power densities for data centers. The enhanced thermal properties of oil can lead to considerable savings in both the upfront and operating costs over traditional air cooling methods. Despite recent findings showing the improved cooling efficiency and cost savings of oil as a cooling fluid, this technique is still not widely adopted. Many uncertainties and concerns persist regarding the non-thermal aspects of an oil immersion cooled data center. This work presents useful information regarding a variety of factors related to the operation of an oil cooled data center. Pertinent material property considerations such as the chemistry, flammability, material compatibility, human health effects, and sustainability of mineral oil are discussed. A general introduction as to the chemical composition and production of mineral oils, synthetic oils, and other vegetable based oils is provided on a comparative basis. A discussion of the trade-offs in thermal performance based on pumping power and cost of various oils types is presented. The dielectric nature of oils is critical to their success as a cooling fluid for electronic applications. Factors such as temperature, voltage, and age that affect this property are reviewed. Flammability of oils is a valid concern when immersing costly IT equipment and the pertinent concerns of this aspect are reviewed. Leeching of materials, especially plastics, is a reoccurring concern expressed regarding mineral oil immersed IT equipment. The health implications associated with such mechanisms will be evaluated. Mineral oils are by products of petroleum refining processes and as such, may bring forth sustainability concerns associated with their use and disposal. The long term stability and performance of key physical and material parameters of oils used in applications such as high voltage power are typically monitored. The similarity and implications of longevity of oils when used for data center applications will be examined. Other issues related to the design, operation, and serviceability of submerged IT equipment and racks will also be addressed. Switching to an oil immersion cooled data center typically brings about several new design and operational changes compared to the well-established air cooling technology. Considerations regarding design issues such as secondary containment requirements are often not required in conventional facilities. A critical element of oil cooling often cited by opponents of the technology is the issue of serviceability of IT equipment. This presentation will discuss some of the additional features a data center may need in place to help alleviate these concerns, as well as, best practices based on experience and observations by the authors. The discussion presented here is based primarily on literature gathered on the subject and quantifiable data gathered by the authors.|
|Jimil M. Shah, Graduate Student
University of Texas at Arlington