Design of Simulated Server Racks for Data Center Research

2011 ◽  
Author(s):  
James F. Smith ◽  
Waleed A. Abdelmaksoud ◽  
Hamza S. Erden ◽  
John F. Dannenhoffer ◽  
Thong Q. Dang ◽  
...  
Keyword(s):  
High Power ◽  
Data Center ◽  
Temperature Limit ◽  
Operating Conditions ◽  
Heating Power ◽  
Substantial Part ◽  
Thermal Mass ◽  
Safety Issues ◽  
Typical Data ◽  
Line Temperature

Conducting experiments on real high-density computer servers can be an expensive and risky task due to the risks associated with unintended inlet temperatures that exceed the server’s red-line temperature limit. Presented herein is the development of the simulated chassis that mimic real computer servers. Briefly, twelve high-power simulated chassis were designed and built to accurately simulate the actual operating conditions of a real computer chassis in a data center. Each simulated chassis is designed to have approximately 300 Pa pressure drop at a flow rate of 600 cfm to represent a real IBM server chassis. Additionally, the simulated chassis are designed to match the thermal mass of a real server. Eight of the simulated chassis were designed to have constant speed fans and variable heating power while the remaining four chassis were designed to have variable speed fans and variable heating power. Further discussions about the design phase of the simulated chassis are the substantial part of this paper. Underlining the challenges and safety issues with high-power chassis, guidelines for designing and constructing a chassis that simulates the real environment of a typical data center are presented.

Facility Cooling Failure Analysis of Direct Liquid Cooling System in Data Centers

2018 ◽  
Author(s):  
Sami Alkharabsheh ◽  
Udaya L. N. Puvvadi ◽  
Bharath Ramakrishnan ◽  
Kanad Ghose ◽  
Bahgat Sammakia
Keyword(s):  
Data Center ◽  
Cooling System ◽  
Rate Of Change ◽  
Operating Conditions ◽  
Thermal Mass ◽  
Liquid Cooling ◽  
Chip Temperature ◽  
Fan Speed ◽  
Liquid Cooling System ◽  
The Impact

This work experimentally studies the impact of facility cooling failure of a direct liquid cooling (DLC) system on the IT equipment (ITE). The facility side of a DLC system removes the heat from a secondary loop — in direct contact with the ITE — and discard it in a chiller loop or ambient. The CPU utilization and coolant set point temperature (SPT) are varied to understand the effect of failure under different operating conditions. The ITE response is studied in terms of chip temperature and power, and fan speed. It was found that failure of the facility cooling system is not hazardous to the IT operation. The rate of change in temperature after failure is low and is sufficient to turn the ITE off safely. This is attributed to the surrounding air in the data center and the thermal mass of the cooling system.

scholarly journals Decommissioning and Safety Issues of Liquid-Mercury Waste Generated from High-Power Spallation Sources with Particle Accelerators

2009 ◽  
Vol 168 (2) ◽  
pp. 264-269
Author(s):  
S. Chiriki ◽  
J. Fachinger ◽  
R. Moormann ◽  
H.-K. Hinssen ◽  
A. Bukaemskiy ◽  
...  
Keyword(s):  
High Power ◽  
Particle Accelerators ◽  
Safety Issues ◽  
Liquid Mercury

Prediction of Hot Aisle Partition Airflow Boundary Conditions

2013 ◽  
Author(s):  
Zhihang Song ◽  
Bruce T. Murray ◽  
Bahgat Sammakia
Keyword(s):  
Boundary Conditions ◽  
Data Center ◽  
Computation Time ◽  
Design Tool ◽  
Operating Conditions ◽  
Ann Model ◽  
Flow Rates ◽  
Level Model ◽  
Optimization Methodology ◽  
Artificial Neural Network Ann

The integration of a simulation-based Artificial Neural Network (ANN) with a Genetic Algorithm (GA) has been explored as a real-time design tool for data center thermal management. The computation time for the ANN-GA approach is significantly smaller compared to a fully CFD-based optimization methodology for predicting data center operating conditions. However, difficulties remain when applying the ANN model for predicting operating conditions for configurations outside of the geometry used for the training set. One potential remedy is to partition the room layout into a finite number of characteristic zones, for which the ANN-GA model readily applies. Here, a multiple hot aisle/cold aisle data center configuration was analyzed using the commercial software FloTHERM. The CFD results are used to characterize the flow rates at the inter-zonal partitions. Based on specific reduced subsets of desired treatment quantities from the CFD results, such as CRAC and server rack air flow rates, the approach was applied for two different CRAC configurations and various levels of CRAC and server rack flow rates. Utilizing the compact inter-zonal boundary conditions, good agreement for the airflow and temperature distributions is achieved between predictions from the CFD computations for the entire room configuration and the reduced order zone-level model for different operating conditions and room layouts.

The Effect of Under-Floor Obstructions on Data Center Perforated Tile Airflow

2011 ◽  
Author(s):  
James W. VanGilder ◽  
Zachary R. Sheffer ◽  
Xuanhang Simon Zhang ◽  
Collyn T. O’Kane
Keyword(s):  
Best Practices ◽  
Data Center ◽  
Flow Model ◽  
Design Parameters ◽  
Tile Type ◽  
Airflow Distribution ◽  
Specific Advice ◽  
Typical Data ◽  
Cfd Analyses ◽  
Potential Flow Model

Typical data center architectures utilize a raised floor; cooling airflow is pumped into an under-floor plenum and exits through perforated floor tiles located in front of IT equipment racks. The under-floor space is also a convenient place to locate critical building infrastructure, such as chilled-water piping and power and network cabling. Unfortunately, the presence of such objects can disrupt the distribution of cooling airflow. While the effects of other design parameters, such as room layout, plenum depth, perforated tile type, and leakage paths, have been systematically studied — and corresponding best-practices outlined, there is no specific advice in the literature with regard to the effect of under-floor infrastructure on airflow distribution. This paper studies the effects of such obstructions primarily through CFD analyses of several layouts based on actual facilities. Additionally, corresponding scenarios are analyzed using a Potential Flow Model (PFM), which includes a recently-proposed obstruction-modeling technique. It is found that under-floor obstructions significantly affect airflow distribution only when they are located very near perforated tiles and cooling units and occupy a substantial fraction of the total plenum depth.

scholarly journals Challenges of Hot Tapping Into a Sour Gas Transmission Line

2000 ◽  
Author(s):  
Ray Goodfellow ◽  
Rory Belanger
Keyword(s):  
Transmission Line ◽  
Operating Conditions ◽  
New Production ◽  
Line Pressure ◽  
Welding Procedure ◽  
Sour Service ◽  
Line Temperature ◽  
Procedure Development ◽  
Design Pressure ◽  
Sour Gas

Chevron Canada Resources recently completed a hot tap on the Simonette high-pressure sour gas transmission line near Grande Prairie, Alberta. The hot tap was required to bring on new production into the Simonette pipeline without shutting in existing production. The hot tap was completed under full line pressure and gas/condenstate flow during the winter with temperatures averaging −20°C. The design pressure of the 12 “ Gr. 359 Cat II pipeline is 9930 kPa and the line operates at 8200 kPa. The gas in the main transmission line is approximately 2% H2S and 4% CO2. The gas being brought on through the 4″ hot tap tie-in was 21% H2S and 5% CO2. At the tie-in point the transmission line temperature was 3°C. Safely welding on the pipeline under these conditions was a considerable technical challenge. In welding sour service lines it is critical that the final weld hardness be below Vickers 248 micro hardness. This can be very difficult to achieve when welding on a line transporting a quenching medium of gas and condensate. In addition, hydrogen charging of the steel from operation in sour service can lead to hydrogen embrittlement during welding. Ludwig & Associates developed the hot tap weld procedure and extensively tested the procedure to ensure that suitable weld microhardness was achievable under pipeline operating conditions. As part of the procedure development the welder who would perform the hot tap was tested repeatedly until he could confidently and successfully complete the weld. During fieldwork, the welding was rigorously monitored to ensure procedural compliance thereby minimizing the possibility of elevated hardness zones within the completed weldment. This paper will detail with the technical development of the hot tap welding procedure and the successful field implementation.

scholarly journals RELATION BETWEEN PORE MODEL AND CENTER-LINE TEMPERATURE IN HIGH BURN-UP UO2 PELLET

2010 ◽  
Vol 7 (2) ◽  
pp. 147-153
Author(s):  
Suwardi Suwardi
Keyword(s):  
Thermal Properties ◽  
Temperature Distribution ◽  
Power Distribution ◽  
Distribution Model ◽  
Center Line ◽  
Pore Model ◽  
Pellet Temperature ◽  
Typical Data ◽  
Line Temperature ◽  
Centerline Temperature

Relation between pore model and center-line temperature of high burn up UO2 Pellet. Temperature distribution has been evaluated by using different model of pore distribution. Typical data of power distribution and coolant data have been chosen in this study. Different core model and core distribution model have been studied for related temperature, in correlation with high burn up thermal properties. Finite element combined finite different adapted from Saturn-1 has been used for calculating the temperature distribution. The center-line temperature for different pore model and related discussion is presented.   Keywords: pore model, high burn up, UO2 pellet, centerline temperature.

scholarly journals Thermal Performance and Efficiency of a Mineral Oil Immersed Server Over Varied Environmental Operating Conditions

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Richard Eiland ◽  
John Edward Fernandes ◽  
Marianna Vallejo ◽  
Ashwin Siddarth ◽  
Dereje Agonafer ◽  
...  
Keyword(s):  
Flow Rate ◽  
Thermal Performance ◽  
Data Center ◽  
Mineral Oil ◽  
Operating Conditions ◽  
Published Data ◽  
Inlet Temperature ◽  
Air Cooling ◽  
Bulk Fluid ◽  
Oil Immersion

Complete immersion of servers in dielectric mineral oil has recently become a promising technique for minimizing cooling energy consumption in data centers. However, a lack of sufficient published data and long-term documentation of oil immersion cooling performance make most data center operators hesitant to apply these approaches to their mission critical facilities. In this study, a single server was fully submerged horizontally in mineral oil. Experiments were conducted to observe the effects of varying the volumetric flow rate and oil inlet temperature on thermal performance and power consumption of the server. Specifically, temperature measurements of the central processing units (CPUs), motherboard (MB) components, and bulk fluid were recorded at steady-state conditions. These results provide an initial bounding envelope of environmental conditions suitable for an oil immersion data center. Comparing with results from baseline tests performed with traditional air cooling, the technology shows a 34.4% reduction in the thermal resistance of the system. Overall, the cooling loop was able to achieve partial power usage effectiveness (pPUECooling) values as low as 1.03. This server level study provides a preview of possible facility energy savings by utilizing high temperature, low flow rate oil for cooling. A discussion on additional opportunities for optimization of information technology (IT) hardware and implementation of oil cooling is also included.

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