Here is the abstract you requested from the Thermal_2016 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.
|Optimization of water and energy usage for indirect evaporative cooling system using CFD techniques.|
|Keywords: Indirect evaporative cooling, CFD analysis , power and water consumption technique|
|Air-cooling is most efficient and economical way now a day though it has some limitations. Heat-exchanger design is a critical part of data center facility design in which air and liquid cooling are being used. Air to liquid cooling provides higher heat transfer rate and overcome limitations of air-cooling with high cost. Heat-exchangers are implemented with mechanical cooling systems where compressor- pump system uses refrigeration cycle to cool data center air, which consume more energy. Similar heat exchanger method of adiabatic cooling by evaporation of water into air which is evaporative cooling technique. Evaporative cooling has gained rapid acceptance because the process relies on the evaporation of water to produce significant cooling with extremely low energy consumption. Even with all the sophisticated technology available, evaporation is still one of the simplest methods of cooling air, and the principle of evaporative cooling remains a cost- effective method for environmental control. It includes two different kinds of methods- i) direct evaporative cooling(DEC) ii) Indirect evaporative cooling(IEC). Wet cooling media is being widely used in DEC. The media provides a durable, highly wettable, extended surface with low air-pressure drop. Wet cooling media reduces dry bulb temperature with expense of humidity increment. This can cause limitation in humid areas, thus IEC is good alternative. Indirect evaporative cooling sensibly cools the dry bulb temperature with use of water-to-air heat exchanger. Separate system had been studied previously for greenhouse application and cooling towers. For this type of application efficient operation of both units can reduce power and water usage significantly which is the purpose of this study. In this study, an existing IEC unit is modeled in a computational fluid dynamics(CFD) tool. Here use of IEC mainly focus on using as little energy and water as possible to dramatically reduce energy costs. For existing data centers ASHRAE recommends a humidity level of 41.9°F dew point to 60%RH and an allowable range of between 20-80%RH. In Indirect Evaporative cooling(IEC) unit, the recirculating pump is throttling chilled water to heat exchanger unit through nozzle, which cools the surface of the tube. These tubes sensibly cool the primary hot air stream on the exterior side of the tubes. Using psychrometric chart data in CFD model of IEC showing significant reduces in dry bulb temperature. Furthermore, Parametric study of water intake, inlet- outlet and operation for indirect cooling unit has been studied to optimize the cooling path. To cool dry bulb temperature up to psychrometric chart range, indirect unit can operate simultaneously with DEC unit or separately as per the ambient condition.|
|Mansi V Prajapati, Graduate Student
University of Texas at Arlington