scholarly journals Best Determined Position of Vents Based on Jet Cooling Model

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Na Huang
Keyword(s):  
Data Centers ◽  
Utilization Efficiency ◽  
Optimal Position ◽  
Cold Air ◽  
Jet Cooling ◽  
Hot Air ◽  
Cooling Model

 In some data centers, cold air is required to act on the cabinet to achieve cooling requirements, and the mixing of cold air and hot air reduces the utilization efficiency of cold air. In order to solve this problem, a jet cooling model is established to solve the optimal position of the outlet through the movement of cold air.

Optimization of Cold Aisle Isolation Designs for a Data Center With Roofs and Doors Using Slits

2009 ◽  
Author(s):  
Srujan Gondipalli ◽  
Bahgat Sammakia ◽  
Siddarth Bhopte ◽  
Roger Schmidt ◽  
Madhusudan K. Iyengar ◽  
...  
Keyword(s):  
Data Center ◽  
Data Centers ◽  
Heat Fluxes ◽  
Low Velocity ◽  
Cold Air ◽  
Average Temperature ◽  
Hot Air ◽  
Large Numbers ◽  
Typical Data ◽  
Air Streams

Data centers are facilities that house large numbers of computer servers that typically dissipate high power. With the rapid increase in the heat flux of such systems, their thermal management represents an economic and environmental challenge that needs to be addressed [2]. Considering the trends of increasing heat loads and heat fluxes, the focus for users is in providing adequate airflow through the equipment at a temperature that meets the manufacturers’ requirements. Data centers house IT equipment in racks typically arranged in rows which face one another. Alternating cold and hot aisles are formed and this pattern is repeated across the data center. This approach helps to separate cold and hot air streams; but this does not always suffice in the separation of cold and hot air. The mixing of hot rack exhaust air with cold supply air, short-circuiting of cold air to the coolers and the recirculation of hot air to racks’ inlet are the common phenomena that lead to thermal inefficiencies in a typical data center. Typically in a raised floor data center, increase in rack inlet air temperature is seen because of the infiltration of hot air into the cold aisle from the top (ceiling of the cold aisle) and from edges or sides. Infiltration can be reduced to a certain extent if cold aisles are isolated from ceiling and hot aisles using partially or fully closed doors with slits to manage the airflow. The key is to redistribute the cold air entering the cold aisle along with any infiltration such that the overall average temperature at the rack inlets is below a predefined level. In this paper, different designs were generated with the criteria of achieving no hotspots, a relatively low pressure drop across the servers and low velocity of the air in the cold aisle based on an actual data center model. Several designs are proposed that meet all of the defined constraints.

Impact of Tile Design on Thermal Performance of Open and Enclosed Aisles

2017 ◽  
Author(s):  
Sadegh Khalili ◽  
Mohammad I. Tradat ◽  
Kourosh Nemati ◽  
Mark Seymour ◽  
Bahgat Sammakia
Keyword(s):  
Data Centers ◽  
Area Ratio ◽  
Inlet Temperature ◽  
Open Area ◽  
Cfd Simulations ◽  
Physical Separation ◽  
Hot Air ◽  
Airflow Distribution ◽  
The Impact ◽  
Lower Noise

In raised floor data centers, tiles with high open area ratio or complex understructure are used to fulfill the demand of today’s high-density computing. Using more open tiles reduces pressure drop across the raised floor with the potential advantages of increased airflow and lower noise. However, it introduces the disadvantage of increased non-uniformity of airflow distribution. In addition, there are various tile designs available on the market with different opening shapes or understructures. Furthermore, a physical separation of cold and hot aisles (containment) has been introduced to minimize the mixing of cold and hot air. In this study, three types of floor tiles with different open area, opening geometry, and understructure are considered. Experimentally validated detail models of tiles were implemented in CFD simulations to address the impact of tile design on the cooling of IT equipment in both open and enclosed aisle configurations. Also, impacts of under-cabinet leakage on the IT equipment inlet temperature in the provisioned and under-provisioned scenarios are studied. Finally, a predictive equation for the critical under-provisioning point that can lead to a no-flow condition in IT equipment with weaker airflow systems is presented.

Air Flow Velocity Field Validation and Turbulence Studies on a Single Rack Model in Data Centers

2018 ◽  
Author(s):  
Long Phan ◽  
Beichao Hu ◽  
Cheng-Xian Lin
Keyword(s):  
Thermal Management ◽  
Large Scale ◽  
Data Centers ◽  
Turbulence Models ◽  
Airflow Rate ◽  
Cold Air ◽  
Large Scale Data ◽  
Air Supply ◽  
Equipment Failures ◽  
Air Flow Velocity

Due to the rapid growth in IT demands over the past few decades, the market for data centers also increases dramatically. However, thermal management remains a big issue in the design of large-scale data centers. Although best practices are deployed to utilize perforated tiles together with the hot and cold aisles configuration to improve the thermal management, thermal hotspots are inevitable in IT racks, which causes equipment failures and signal interruptions. Thermal hotspots in air-cooled data centers are due to many factors such as insufficient cold air supply from the raised-floor plenum, air recirculation from hot aisle into cold aisle, airflow non-uniformity at the perforated tiles, etc. One of the ways to mitigate such issues is to uniformly distribute the cold air by properly controlling the airflow rate through perforated tiles. In this study, a validation study of the tile airflow and the rack airflow rate ratio of 20% is carried out using an adopted tile model. Also, several turbulence models are thoroughly investigated, and recommendations are provided for the most accurate and less time-consuming turbulence model when applying to a single rack model.

Effects of Heating Vents in a Tunnel-Type Dryer

2011 ◽  
Vol 189-193 ◽  
pp. 1757-1760
Author(s):  
Chien Hsiung Tsai ◽  
Yao Nan Wang ◽  
Chang Hsien Tai ◽  
Jr Ming Miao ◽  
Jik Chang Leong
Keyword(s):  
Temperature Distribution ◽  
Fuel Consumption ◽  
Flow Rate ◽  
Heating Process ◽  
Computational Results ◽  
Cold Air ◽  
Hot Air ◽  
Air Intake

This work employs FDS to simulate the heating process of a tunnel-type dryer and visualizes the computational results using Smokeview. The inappropriate design of a tunnel-type dryer in a factory has motivated this work. This poorly designed dryer not only has caused terrible fuel consumption but also produced parts some of which are under- or over-cooked. These are caused by the terribly uneven temperature distribution within the dryer. In order to improve the evenness of temperature distribution, this work simulates and investigates the effects of various ventilation schemes. Based on the results, it is found that the hot air intake vent should be placed at the bottom whereas the cold air outtake vent at the top. The flow rate through the intake vents does not have a very significant effect on the temperature distribution after 40 s.

Effective Thermal Management of Data Centers Using Efficient Cabinet Designs

2009 ◽  
Author(s):  
Veerendra Mulay ◽  
Dereje Agonafer ◽  
Gary Irwin ◽  
Darshan Patell
Keyword(s):  
Thermal Management ◽  
Environmental Protection Agency ◽  
Data Center ◽  
Energy Use ◽  
Data Centers ◽  
Energy Usage ◽  
Protection Agency ◽  
Cold Air ◽  
New Concepts ◽  
Entire Nation

Rising heat load trends in data center facilities have raised concerns over energy usage. The environmental protection agency has reported that the energy used in 2006 by data center industry was 1.5% of the total energy usage by entire nation. The experts agree that by year 2010, this usage will approach 2% of the annual energy use nationwide. Although many new concepts such as airside economizers and cogeneration are gaining traction, many data center facilities spend considerable energy in cooling. In this study, various cabinet designs are discussed. Isolating the supplied cold air from hot exhaust air is always a challenge in thermal management of data center facilities. A cabinet design that employs chimney to aid the isolation of hot and cold air is discussed. A computational model of representative data center is created to study the effectiveness of design under various supply air fractions.

Thermal Management Issues in Operational Data Centers: Computational Fluid Dynamics Analysis and Experimental Study

2017 ◽  
Vol 9 (3) ◽  
Author(s):  
Babak Fakhim ◽  
Srinarayana Nagarathinam ◽  
Steven W. Armfield ◽  
Masud Behnia
Keyword(s):  
Thermal Management ◽  
Data Center ◽  
Data Centers ◽  
Electricity Consumption ◽  
Field Measurements ◽  
Hot Air ◽  
Computational Fluid Dynamics Analysis ◽  
Higher Power ◽  
Operational Data ◽  
Management Issues

The increase in the number of data centers in the last decade, combined with higher power density racks, has led to a significant increase in the associated total electricity consumption, which is compounded by cooling inefficiencies. Issues, such as hot air recirculation in the data center room environment, provide substantial challenges in thermal manageability. Three operational data centers have been studied to identify the cooling issues. Field measurements of temperature were obtained and were compared to numerical simulations to evaluate the overall thermal behavior of the data centers and to identify the thermal issues.

scholarly journals Robustness of the Storage in Cloud Data Centers Based on Simple Swarm Optimization Algorithm

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Alireza Chamkoori ◽  
Serajdean Katebi
Keyword(s):  
Data Centers ◽  
Spatial Information ◽  
Data Transfer ◽  
Data Communication ◽  
Pso Algorithm ◽  
Swarm Optimization ◽  
Optimal Position ◽  
Cloud Data ◽  
Learning Automaton ◽  
Cloud Data Centers

Storing extensive data in cloud environments affects service quality, transmission speed, and access to information in systems, which is becoming a growing challenge. In storage improvement, reducing various costs and reducing the shortest path in the storage of distributed cloud data centers are among the important issues in the field of cloud computing. In this paper, particle swarm optimization (PSO) algorithm and learning automaton (LA) are used to minimize the cost of a data center, which includes communication, data transfer, and storage and optimization of communication between data centers. To improve storage in distributed data centers, a new model called LAPSO is proposed by combining LA and PSO, in which LA improves particle control by searching for particle speed and position. In this method, LA moves each particle in the direction where it has the best individual and group experiences. In multipeak problems, it does not fall into local optimums. Results of the experiments are shown on the dataset of spatial information and cadastre of country lands, which includes 13 data centers. The proposed method evaluates and improves the optimal position parameters, minimum route cost, distance, data transfer cost, storage cost, data communication cost, load balance, and access performance better than other methods.

Hot air in Kyoto, cold air in The Hague—the failure of global climate negotiations

Energy Policy ◽  
2002 ◽  
Vol 30 (13) ◽  
pp. 1191-1199 ◽  
Author(s):  
Urs Steiner Brandt ◽  
Gert Tinggaard Svendsen
Keyword(s):  
Global Climate ◽  
Cold Air ◽  
Climate Negotiations ◽  
Hot Air ◽  
The Hague

Experimental Study on Cryogenic Gas Atomization Jet Cooling Difficult-to-Cut Material

2015 ◽  
Vol 1095 ◽  
pp. 736-740
Author(s):  
Xiao Yan Guan ◽  
Ai Sheng Wu
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Phase Change ◽  
Cooling Effect ◽  
Air Cooling ◽  
Gas Atomization ◽  
Cold Air ◽  
Jet Cooling ◽  
Nickel Base ◽  
Phase Change Heat Transfer

Based on pool film boiling, the model of boiling and vaporization to heat transfer is established When droplet jet into cutting zone to cool high temperature wall. Through the transient experiment of cryogenic gas atomization jet cooling high temperature nickel-base alloys and Titanium alloys surface with different water dose. The water dose achieving the best cooling effect is obtained at different temperature on surface of Nickel based alloys and TI-alloy. It is indicated that the water dose to the best cooling effect must be equivalent to the amount of water that materials can vaporize and participate in the phase change heat transfer under certain temperature. When achieving optimal cooling effect, the amount of droplets participating in phase change heat transfer to cool high temperature wall are the most , while comparing the cold air cooling effect and spraying cooling effect at low and high temperature. Result is that either low or high temperature, spraying cooling effect is superior than cold air cooling effect, but at a specific temperature, no lower the temperature of air, the better cooling effect, there is also an optimal air temperature values.

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