Low Energy Dew Point Cooling for Computing Data Centres
Data Centre Open Stage
The cooling systems consume 30% to 40% of energy delivered into the Computing & Data Centres (CDCs), while electricity use in CDCs represents 1.3% of the world total energy consumption. The traditional vapour compression cooling systems for CDCs are neither energy efficient nor environmentally friendly. One of the most promising direction is the application of the dew point cooling system, which has been widely used in other industrial field and potentially has the highest efficiency (20-22 electricity based COP)out of other cooling systems if designed properly. Such a system, comprising a few critical and highly innovative components (i.e., dew point air cooler, adsorbent sorption/regeneration cycle, microchannel loop-heat-pipe (MCLHP) based CDC heat recovery system, paraffin/expanded-graphite based heat storage/ exchanger, and Internet-based intelligent monitoring and control system), is expected to achieve 60% to 90% of electrical energy saving and have a comparable initial price to traditional CDC air conditioning systems, thus removing the above outstanding problems remaining with existing CDC cooling systems. The super high performance has been validated by simulation and preliminary experiment carried out in Hull and other partners’ laboratory recently. The coefficient of performance (COP) of the proposed dew point cooling system reached as high as 37.4 in ideal weather condition, while the average COP of the traditional cooling system is around 3.0. The dynamic simulation also carried out under UK (London) climate for 4 scale type of CDCs (i.e. small, medium, large, super) and 5 application scenarios (room space level, row level, rack level, server level). The result shows dramatic annual electricity saving compare to the reference cases with traditional cooling plan, especially for the application at server level cooling. The results also show that the bigger the CDC`s scale the more electricity would be saved by applying this system. The estimated annual electricity saving for the reference Data centres in UK is 1196 MWh, 7503 MWh, 22524 MWh, and 75947 MWh for small, medium, large and super CDCs respectively.