Research On Directly Introducing Fresh Air System Used In Data Center Air Conditioning Scheme

The energy situation of China is severe, Energy conservation and emissionreduction has become a basic policy of our country. With the development andpopularization of information systems, the number and size of data centers areincreasing rapidly, the power consumption amount of data centers can be a very large.The emitting heat from equipments within data centers is considerable and huge amountof exccesive heat should be removed to outside during the whole year. To maintain thenormal operation of communication equipments, air-conditioning systems need to beequipped and operated throughout the whole year. Air-conditioning system has becomethe main power utilization part of a data center, and its energy consumption can accountfor nearly40%of the total. Reduceing the air conditioning energy consumption is ofgreat significance not only for the contribution to national energy conservation, but alsofor saving operating costs of the data center. Therefore, how to reduce the energyconsumption of air conditioning systems, is an important and worth studying objectivenowadays.Directly introducing fresh air system is mainly used in the winter and transitionalseasons, and the outdoor air is used as the natural cold source for room cooling. Whenthe outdoor air temperature is lower than a certain set value, after the outdoor cold airwas filtered by air filters, then open the air supply apparatus, send the outdoor cold airinto the room directly or after mixing with the return air, thereby the air temperatureinside the sever server room was reduced. Applying directly introducing fresh airsystem is not only to reduce the operation time of refrigeration, but also to extend theservice life of air-conditioning compressor and to reduce the operating systematicalenergy consumption and its costs.In this paper, a typical data center building model located in Beijing area has beenestablished, Energy consumption estimation of air conditioning system equipped byconventional designed method has been done, and then annual (8760h) building thermalload has been calculated and presented by simulation software DeST, energy savingpotentials of a new style air conditioning system with directly introducing fresh air forindoor cooling has also been analysized and illustrated. In the application process of thedirectly introducing fresh air system, fresh air filter must be very much concerned. Inthis paper, the performance of air filters were analyzed theoritically, and the filter resistance performance has been simulated and calculated by fluid dynamics simulationsoftware FLUENT, and the service life of air filters at all dust concentration levels arecalculated briefly. Finally, through comparative analysis of energy consumption on bothdirectly introducing fresh air system and conventional air conditioning system,economical efficiency and feasibility of using the directly introducing fresh air systemare expounded, and reference and guidence for the design and operation of directlyintroducing fresh air system used in data center can be obtained.