New Thermal Management Systems for Data Centers

2011 ◽  
Author(s):  
Mayumi Ouchi ◽  
Yoshiyuki Abe ◽  
Masato Fukagaya ◽  
Takashi Kitagawa ◽  
Haruhiko Ohta ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Management ◽  
High Performance ◽  
Data Centers ◽  
Technology Development ◽  
Management Systems ◽  
Air Conditioner ◽  
Liquid Cooling ◽  
Two Phase ◽  
Development Organization

The almost half amount of power consumption in data centers which has been increasing drastically in late years is due to air conditioner for cooling down the data centers. The present authors proposed new thermal management systems for data centers aiming for the data centers without air conditioning, and R&D subjects have been conducted under the so called Green IT Project sponsored by NEDO (New Energy and Industrial Technology Development Organization). In this system, three liquid cooling methods for CPUs have been developed simultaneously, which are two types of direct liquid cooling with single-phase or two-phase heat exchanger and an indirect liquid cooling with high performance thin heat pipes. To establish this system, five R&D subjects have been conducted. In this paper, current progress of these subjects such as development of heat transfer components, verification test using real server racks, and nanofluids technology for heat transfer enhancement is reported.

Development of Advanced Cooling Network Systems for Data Centers

2010 ◽  
Author(s):  
Yoshiyuki Abe ◽  
Mayumi Ouchi ◽  
Masato Fukagaya ◽  
Takashi Kitagawa ◽  
Haruhiko Ohta ◽  
...  
Keyword(s):  
High Performance ◽  
Data Centers ◽  
Cooling System ◽  
Heat Pipes ◽  
Energy Utilization ◽  
Liquid Cooling ◽  
Network Systems ◽  
Two Phase ◽  
Cooling Systems ◽  
Development Organization

Energy utilization in data centers, especially cooling systems for server racks, needs extensive improvement. The present authors proposed advanced cooling network systems for data centers, and R & D activities have been conducted under the so-called Green IT Project sponsored by NEDO (New Energy and Industrial Technology Development Organization). In the present concept, CPUs in servers are cooled down by either direct liquid cooling system or heat pipes with liquid cooling systems in the condensation region. The liquid cooling systems are integrated in each server rack and among server racks. A series of studies on both single phase and two phase narrow channel heat exchangers, high performance heat pipes with self-rewetting fluids and nanofluids for heat transfer enhancement are ongoing. In addition, a prototype server rack with the cooling network systems is also under development toward commercial products. This paper reports the updated status of the present R & D.

scholarly journals Effect of Nanoparticle Deposition on the Thermal Performance of Evaporator in Thermosyphons

2021 ◽  
Vol 2116 (1) ◽  
pp. 012054
Author(s):  
T Donepudi ◽  
A V Korobko ◽  
J W R Peeters ◽  
S Fateh
Keyword(s):  
Heat Transfer ◽  
Thermal Management ◽  
Electronic Devices ◽  
Heat Transfer Process ◽  
Heat Fluxes ◽  
Management Systems ◽  
Two Phase ◽  
Nanoparticle Deposition ◽  
Promising Alternative ◽  
Conventional Systems

Abstract Rapid advancements in technology have led to the miniaturization of electronic devices which typically dissipate heat fluxes in the order of 100 W/cm2. This has brought about an unprecedented challenge to develop efficient and reliable thermal management systems. Novel cooling technologies such as Two-Phase Thermosyphons that make use of nanofluids provide a promising alternative to the use of conventional systems. This article analytically estimates the effects caused by nanoparticles that deposit on the evaporator surface and their effect on the heat transfer process.

scholarly journals Multi-Physics Equivalent Circuit Models for a Cooling System of a Lithium Ion Battery Pack

Batteries ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 44 ◽  
Author(s):  
Takumi Yamanaka ◽  
Daiki Kihara ◽  
Yoichi Takagishi ◽  
Tatsuya Yamaue
Keyword(s):  
Heat Transfer ◽  
Equivalent Circuit ◽  
Thermal Management ◽  
Flow Rate ◽  
3D Model ◽  
Management Systems ◽  
Li Ion Battery ◽  
Liquid Cooling ◽  
Battery Packs ◽  
Li Ion

Lithium (Li)-ion battery thermal management systems play an important role in electric vehicles because the performance and lifespan of the batteries are affected by the battery temperature. This study proposes a framework to establish equivalent circuit models (ECMs) that can reproduce the multi-physics phenomenon of Li-ion battery packs, which includes liquid cooling systems with a unified method. We also demonstrate its utility by establishing an ECM of the thermal management systems of the actual battery packs. Experiments simulating the liquid cooling of a battery pack are performed, and a three-dimensional (3D) model is established. The 3D model reproduces the heat generated by the battery and the heat transfer to the coolant. The results of the 3D model agree well with the experimental data. Further, the relationship between the flow rate and pressure drop or between the flow rate and heat transfer coefficients is predicted with the 3D model, and the data are used for the ECM, which is established using MATLAB Simulink. This investigation confirmed that the ECM’s accuracy is as high as the 3D model even though its computational costs are 96% lower than the 3D model.

Experimental Characterization of a Unique Carbon Fiber Brush Heat Sink in Two-Phase Heat Transfer

2005 ◽  
Author(s):  
Harish Chengalvala ◽  
Amy S. Fleischer ◽  
G. F. Jones
Keyword(s):  
Heat Transfer ◽  
Carbon Fiber ◽  
Thermal Management ◽  
Thermal Performance ◽  
Heat Sink ◽  
Management Strategies ◽  
Liquid Cooling ◽  
Two Phase ◽  
Two Phase Heat Transfer ◽  
Power Densities

The performance enhancements and footprint decreases of advanced electronic devices result in soaring power densities which may in turn lead to elevated operating temperatures. As elevated device temperatures lead to decreased device reliability and increased thermal stresses, it is necessary to employ aggressive thermal management techniques to maintain an acceptable junction temperature at high power densities. For this reason, interest is growing in a variety of liquid cooling techniques This study analyzes an advanced engineered-material heat sink which provides significant improvements in thermal management strategies for advanced electronics. The heat sink consists of a very large number of small cross-section fins fabricated from carbon pitch fibers. For these carbon pitch fibers, the high thermal conductivity reduces the temperature drop along the length of the fin creating a longer effective fin length than for copper fins. The longer length results in more heat transfer surface area and a more effective heat sink. In liquid cooling, the rough surface of the fin will provide multiple bubble nucleation sites, strongly promoting active two-phase heat transfer over the entire fin surface. This surface enhancement is expected to lead to significant increases in performance over conventional heat sinks. This experimental analysis characterizes the thermal performance of the carbon-fiber heat sink in two-phase closed loop thermosyphon operation using FC72 as the operating fluid. The influence of power load, thermosyphon fill volume and condenser operating temperature on the overall thermal performance is examined. The results of this experiment provide significant insight into the possible implementation and benefits of carbon fiber heat sink technology in two-phase flow leading to significant improvements in thermal management strategies for advanced electronics.

An Assessment of Effects of Nanofluids on Heat Transfer Performance of Two-Phase Cooling Systems

2021 ◽  
Author(s):  
Alexander V. Korobko ◽  
Sana Fateh
Keyword(s):  
Heat Transfer ◽  
Thermal Management ◽  
Data Centers ◽  
Heat Transfer Performance ◽  
Future Research ◽  
Transfer Performance ◽  
Two Phase ◽  
Cooling Systems ◽  
The Impact ◽  
Two Phase Cooling

Abstract The recent increase in complexity of computations and the expansion of edge computing have led to the emergence of high power density data centers with an urgent demand for more advanced thermal management systems. Two-phase passive cooling systems such as thermosyphons and heat pipes have been widely used in industry to maintain the temperature of the servers below the threshold of failure and carry away a large quantity of heat from a small area. Such systems are economically viable and sustainable since they have no moving parts and consume lower power. However, an upgrade to these cooling systems is imminent due to the ever-increasing power densities of the data centers and more challenging thermal management issues faced by the industry. Nanofluids have emerged recently as a new class of cooling liquids claiming to enhance the heat transfer performance in single and two-phase cooling systems. As per several studies presented in this paper, the thermal performance of thermosyphons is shown to be enhanced by employing nanofluids. In this paper, a comprehensive review is presented on the effect of nanofluids in improving the Critical Heat Flux (CHF) and Heat Transfer Coefficient (HTC) in two-phase cooling systems. The boiling phenomenon and working principles of thermosyphons will be discussed to understand the underlying mechanisms affecting heat transfer in the evaporator region, where the heat is absorbed from the source. The impact of nanoparticle features, concentration, and deposition pattern on HTC enhancement will also be studied. Additionally, estimates of the heat dissipation improvement by using nanofluids along with the bottlenecks and challenges faced in applying such fluids practically are reviewed as well. In conclusion, recommendations are made for future research needed to overcome the risks and commercialize the nanofluids in two-phase cooling systems for providing significant improvement in heat transfer performance as compared to conventional working fluids.

A comparative study between air cooling and liquid cooling thermal management systems for a high-energy lithium-ion battery module

2021 ◽  
Vol 198 ◽  
pp. 117503 ◽  
Author(s):  
Mohsen Akbarzadeh ◽  
Theodoros Kalogiannis ◽  
Joris Jaguemont ◽  
Lu Jin ◽  
Hamidreza Behi ◽  
...  
Keyword(s):  
Comparative Study ◽  
Lithium Ion Battery ◽  
Thermal Management ◽  
Lithium Ion ◽  
High Energy ◽  
Management Systems ◽  
Air Cooling ◽  
Liquid Cooling ◽  
Battery Module

Exergy Analysis of Data Center Thermal Management Systems

2003 ◽  
Author(s):  
Amip J. Shah ◽  
Van P. Carey ◽  
Cullen E. Bash ◽  
Chandrakant D. Patel
Keyword(s):  
Thermal Management ◽  
Data Center ◽  
Data Centers ◽  
Exergy Analysis ◽  
Thermal Control ◽  
Management Systems ◽  
World Systems ◽  
Sample Data ◽  
Potential Applications ◽  
Temperature Ranges

Data centers today contain more computing and networking equipment than ever before. As a result, a higher amount of cooling is required to maintain facilities within operable temperature ranges. Increasing amounts of resources are spent to achieve thermal control, and tremendous potential benefit lies in the optimization of the cooling process. This paper describes a study performed on data center thermal management systems using the thermodynamic concept of exergy. Specifically, an exergy analysis has been performed on sample data centers in an attempt to identify local and overall inefficiencies within thermal management systems. The development of a model using finite volume analysis has been described, and potential applications to real-world systems have been illustrated. Preliminary results suggest that such an exergy-based analysis can be a useful tool in the design and enhancement of thermal management systems.

New Thermal Management Systems for Data Centers

2012 ◽  
Vol 4 (3) ◽  
Author(s):  
Mayumi Ouchi ◽  
Yoshiyuki Abe ◽  
Masato Fukagaya ◽  
Takashi Kitagawa ◽  
Haruhiko Ohta ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Single Phase ◽  
Data Centers ◽  
Cooling System ◽  
Heat Pipes ◽  
Air Cooling ◽  
Liquid Cooling ◽  
Two Phase ◽  
Cooling Jacket ◽  
Cooling Methods

Energy consumption in data centers has seen a drastic increase in recent years. In data centers, server racks are cooled down in an indirect way by air-conditioning systems installed to cool the entire server room. This air cooling method is inefficient as information technology (IT) equipment is insufficiently cooled down, whereas the room is overcooled. The development of countermeasures for heat generated by IT equipment is one of the urgent tasks to be accomplished. We, therefore, proposed new liquid cooling systems in which IT equipment is cooled down directly and exhaust heat is not radiated into the server room. Three cooling methods have been developed simultaneously. Two of them involve direct cooling; a cooling jacket is directly attached to the heat source (or CPU in this case) and a single-phase heat exchanger or a two-phase heat exchanger is used as the cooling jacket. The other method involves indirect cooling; heat generated by CPU is transported to the outside of the chassis through flat heat pipes and the condensation sections of the heat pipes are cooled down by coolant with liquid manifold. Verification tests have been conducted by using commercial server racks to which these cooling methods are applied while investigating five R&D components that constitute our liquid cooling systems: the single-phase heat exchanger, the two-phase heat exchanger, high performance flat heat pipes, nanofluid technology, and the plug-in connector. As a result, a 44–53% reduction in energy consumption of cooling facilities with the single-phase cooling system and a 42–50% reduction with the flat heat pipe cooling system were realized compared with conventional air cooling system.

On Efficient Passive Cooling of Control Rod Drivers

2013 ◽  
Author(s):  
A. N. Gershuni ◽  
A. P. Nishchik ◽  
V. G. Razumovskiy ◽  
I. L. Pioro
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
High Performance ◽  
Cooling System ◽  
Vertical Channel ◽  
Passive Cooling ◽  
Primary Circuit ◽  
Two Phase ◽  
Primary Coolant ◽  
Control Rod

Experimental research of natural convection and the ways of its suppression in an annular vertical channel to simulate the conditions of cooling the control rod drivers of the reactor protection system (RPS) in its so-called wet design, where the drivers are cooled by primary circuit water supplied due to the system that includes branched pipelines, valves, pump, heat exchanger, etc., is reported. Reliability of the drivers depends upon their temperature ensured by operation of an active multi-element cooling system. Its replacement by an available passive cooling system is possible only under significant suppression of natural convection in control rod channel filled with primary coolant. The methods of suppression of natural convection proposed in the work have demonstrated the possibility both of minimization of axial heat transfer and of almost complete elimination of temperature non-uniformity and oscillation inside the channel under the conditions of free travel of moving element (control rod) in it. The obtained results widen the possibilities of substitution of the active systems of cooling the RPS drivers by reliable passive systems, such as high-performance heat-transfer systems of evaporation-condensation type with heat pipes or two-phase thermosyphons as heat-transferring elements.

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