| Popis: |
The rapid growth in data centres has resulted in their consumption of up to 100 times more energy per square metre than office accommodation. IT equipment and systems, housed in data centres, consume a considerable amount of electricity. Energy consumption of data centres can be severely and unnecessarily high due to inadequate localised cooling and densely packed server rack layouts. To highlight the importance of cooling issues in data centres, operational data centres are studied using computational fluid dynamics (CFD). Field measurements of temperature are performed. Numerical analysis of flow and temperature fields is conducted in order to evaluate the thermal behaviour of the data centre. A number of undesirable hotspots are identified. To rectify the problem, a few practical design and remedial solutions to improve the cooling effectiveness are proposed and examined to allow a reduced air-conditioning power requirement. Rack-level architecture and layouts have also been found to have a significant impact on the performance of server cooling systems. In this regard, semi-populated racks are modelled with various server arrangements and void positioning accommodated in a prototype data centre. In raised-floor data centres, the perforated tile flow rate distribution is fundamentally a fluid mechanics problem. The effects of position of the under-floor blockages and percentage opening of perforated tile are studied using CFD. Detailed thermodynamic analysis of air-cooled raised-floor data centres for exploring their optimised performance is performed in this thesis. Exergy based performance metric (EPM) is proposed to assess the irreversibilities in the data centre airspace. Detailed comparison is undertaken of the performance metrics based on the first and Second Laws of thermodynamics. |
