Reliability Considerations for Oil Immersion-Cooled Data Centers

Abstract

The improved efficiency of mineral oil may offer simplicity in facility design compared to traditional air cooling and provide a means for cost savings. Despite its improved cooling efficiency and cost savings, a mineral oil immersion cooling technique is still not widely implemented and original equipment manufacturers are reluctant to jeopardize sales of existing air-based cooling system equipment. Only compelling physics regarding thermal performance of direct immersion cooling is not enough for data center operators. Many uncertainties and concerns persist regarding the effects of mineral oil immersion cooling on the reliability of information technology (IT) equipment both at the component and chassis level. This paper is a first attempt at addressing this challenge by reviewing the changes in physical and chemical properties of IT equipment materials like polyvinyl chloride (PVC), printed circuit board (PCB), and capacitors and characterizes the interconnect reliability of materials. The changes in properties of a mineral oil like kinematic viscosity and dielectric strength are also cited as important factors and discussed briefly. The changes in mechanical properties like elasticity, hardness, swelling, and creep are being shown in the paper for thermoplastic materials. The chemical reaction between material and mineral oil as a function of time and temperature is also conferred. The literature gathered on the subject and quantifiable data gathered by the authors provide the primary basis for this research document.

Computing systems in a pseudomarine operational environment: design and initial test results

“…Liquid immersion is recognized as a viable technological solution to enhance data centre performance usage effectiveness. In this regard, advanced hydro-fluorocarbon liquids 3 (Kawaguchi et al, 2017) and mineral oils (Shah et al, 2019) are reported to have been used. However, the use of these specialized fluids has high costs due to the high cost of fluid acquisition.…”

“…In transitioning from air cooled systems to liquid cooling systems or immersion oil-based cooling systems for data centers, the reliability is an important performance parameter that should be considered. The impact of mineral oil data center cooling on data center reliability receives consideration in (Shah et al 2019). Shah et al (2019) recognize the suitability of using mineral oil-based cooling for server farm operation.…”

“…The impact of mineral oil data center cooling on data center reliability receives consideration in (Shah et al 2019). Shah et al (2019) recognize the suitability of using mineral oil-based cooling for server farm operation. It is recognized that submerging servers in dielectric mineral oil reduces energy consumption of server farms.…”

“…It is recognized that submerging servers in dielectric mineral oil reduces energy consumption of server farms. The discussion in Shah et al (2019) recognizes that proprietary mineral oil cooling solutions have been designed and exist. However, it is recognized that mineral oil has the potential of reacting with components of the computing system.…”

“…direct to chip cooling and immersion cooling has been recognized. The study in Shah et al (2019) notes that direct to chip cooling has been adopted by a significant number of original equipment manufacturers. The identified challenges of direct to chip cooling are non-uniform heat dissipation, potential occurrence of vendor lock-in and risk of leak on critical components.…”