CFD-based Comparison Study of Hot Aisle Containment and Cold Aisle Containment Solutions in High-density Data Centers

2020 ◽  
Vol 32 (9) ◽  
pp. 419-434
Author(s):  
Jinkyun Cho ◽  
Wonbae Suh ◽  
Jesang Woo
Keyword(s):  
Data Centers ◽  
High Density ◽  
Comparison Study ◽  
Density Data ◽  
Cold Aisle Containment

scholarly journals A Comparative CFD Study of Two Air Distribution Systems with Hot Aisle Containment in High-Density Data Centers

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6147
Author(s):  
Jinkyun Cho ◽  
Jesang Woo ◽  
Beungyong Park ◽  
Taesub Lim
Keyword(s):  
Thermal Performance ◽  
Data Center ◽  
Distribution Systems ◽  
Data Centers ◽  
High Density ◽  
Operating Conditions ◽  
Air Distribution ◽  
Density Data ◽  
Computational Fluid Dynamics Analysis ◽  
Hard Floor

Removing heat from high-density information technology (IT) equipment is essential for data centers. Maintaining the proper operating environment for IT equipment can be expensive. Rising energy cost and energy consumption has prompted data centers to consider hot aisle and cold aisle containment strategies, which can improve the energy efficiency and maintain the recommended level of inlet air temperature to IT equipment. It can also resolve hot spots in traditional uncontained data centers to some degree. This study analyzes the IT environment of the hot aisle containment (HAC) system, which has been considered an essential solution for high-density data centers. The thermal performance was analyzed for an IT server room with HAC in a reference data center. Computational fluid dynamics analysis was conducted to compare the operating performances of the cooling air distribution systems applied to the raised and hard floors and to examine the difference in the IT environment between the server rooms. Regarding operating conditions, the thermal performances in a state wherein the cooling system operated normally and another wherein one unit had failed were compared. The thermal performance of each alternative was evaluated by comparing the temperature distribution, airflow distribution, inlet air temperatures of the server racks, and recirculation ratio from the outlet to the inlet. In conclusion, the HAC system with a raised floor has higher cooling efficiency than that with a hard floor. The HAC with a raised floor over a hard floor can improve the air distribution efficiency by 28%. This corresponds to 40% reduction in the recirculation ratio for more than 20% of the normal cooling conditions. The main contribution of this paper is that it realistically implements the effectiveness of the existing theoretical comparison of the HAC system by developing an accurate numerical model of a data center with a high-density fifth-generation (5G) environment and applying the operating conditions.

scholarly journals Research on cloud computing high-density data center infrastructure and environment matching technology

2021 ◽  
Vol 336 ◽  
pp. 02028
Author(s):  
Lianteng Shen ◽  
Shengpan Qian ◽  
Tianyi Zhai ◽  
Ling Li ◽  
Zhe Li
Keyword(s):  
Cloud Computing ◽  
Data Center ◽  
Data Centers ◽  
Rapid Development ◽  
High Density ◽  
Density Data ◽  
Virtualization Technology ◽  
Software And Hardware ◽  
New Infrastructure

The current rapid development of cloud computing and networks has put forward new requirements for the construction of new infrastructure such as data centers. This paper compares traditional data centers and high-density data centers, proposes a three-tier infrastructure for high-density data centers, and analyzes the data center environment. To solve the obvious problem of software and hardware heterogeneity in high-density data centers, this paper uses virtualization technology to pool resources in high-density data centers and introduces SOA architecture to manage software and hardware resources hierarchically. Finally, the data center infrastructure and environment matching technology are studied.

Comparative Thermal and Energy Analysis of a Hybrid Cooling Data Center With Rear Door Heat Exchangers

2013 ◽  
Author(s):  
Tianyi Gao ◽  
Emad Samadiani ◽  
Bahgat Sammakia ◽  
Roger Schmidt
Keyword(s):  
Energy Consumption ◽  
Data Center ◽  
Heat Exchangers ◽  
Data Centers ◽  
Cooling System ◽  
High Density ◽  
Cooling Systems ◽  
Density Data ◽  
Rear Door ◽  
Hybrid Cooling

Data centers consume a considerable amount of energy which is estimated to be about 2 percent of the total electrical energy consumed in the US, and their power consumption continues to increase every year. It is also estimated that roughly 30–40 percent of the total energy used in a data center is due to the thermal management systems. So, there is a strong need for better cooling methods which could improve the cooling capacity and also reduce energy consumption for high density data centers. In this regard, liquid cooling systems have been utilized to deal with demanding cooling and energy efficiency requirements in high density data centers. In this paper, a hybrid cooling system in data centers is investigated. In addition to traditional raised floor, cold aisle-hot aisle configuration, a liquid-air hybrid cooling system consisting of rear door heat exchangers attached to the back of racks is considered. The room is analyzed numerically using two CFD based simulation approaches for modeling rear door heat exchangers that are introduced in this study. The presented model is used in the second section of the paper to compare the hybrid cooling system with traditional air cooling systems. Several case studies are taken into account including the power increases in the racks and CRAC unit failure scenarios. A comparison is made between the hybrid cooling room and a purely air cooled room based on the rack inlet temperatures. Also in this study, total energy consumption by the cooling equipment in both air-cooled and hybrid data centers are modeled and compared with each other for different scenarios. The results show that under some circumstances the hybrid cooling could be an alternative to meet the ASHRAE recommended inlet air temperatures, while at the same time it reduces the cooling energy consumption in high density data centers.

A Field Investigation Into the Limits of High-Density Air-Cooling

2013 ◽  
Author(s):  
Michael K. Patterson ◽  
Randall Martin ◽  
J. Barr von Oehsen ◽  
Jim Pepin ◽  
Yogendra Joshi ◽  
...  
Keyword(s):  
Negative Pressure ◽  
Data Centers ◽  
Management Practices ◽  
Field Investigation ◽  
High Density ◽  
Cfd Modeling ◽  
Air Cooling ◽  
Density Data ◽  
Operational Conditions ◽  
Particle Imaging

In this paper we report on a field investigation into airflow management challenges in high density data centers. This field investigation has also served to validate laboratory investigations into high density air cooling issues. In data centers with significant power consumption, and consequently high cooling loads per rack, high volumes of room airflow are required to meet server cooling airflow requirements. These volumes of air can be difficult to deliver in raised floor hot aisle / cold aisle layouts. The velocity of the airflow is such that it creates a negative pressure near the bottom of the rack. This negative pressure entrains air from under and behind the rack, causing recirculation and warmer air being provided to the servers at the base of the rack. This can cause operational problems and server performance impacts. This phenomenon has been demonstrated in previous papers reporting on test data using particle imaging velocimetry (PIV) techniques. The current work validates those studies by looking at airflow, infrared thermography, and actual IT performance while the under rack recirculation flows are occurring. Additionally, we demonstrate significant improvement by employing rigorous airflow management practices. We also discuss the limitations of current CFD modeling, the majority of which does not have sufficient grid-wise resolution to capture the problem. Further we discuss typical operational conditions that have suppressed the problem (or perhaps the awareness of) to date. Finally, the paper recommends best practices to mitigate the problem in high density data centers.

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