Optimal Flow Control and Single Split Architecture Exploration for Fluid-Based Thermal Management

2019 ◽  
Vol 141 (8) ◽  
Author(s):  
Satya R. T. Peddada ◽  
Daniel R. Herber ◽  
Herschel C. Pangborn ◽  
Andrew G. Alleyne ◽  
James T. Allison
Keyword(s):  
Thermal Management ◽  
High Performance ◽  
Dynamic Models ◽  
Cooling System ◽  
Rooted Tree ◽  
Flow Distribution ◽  
Modeling Framework ◽  
System Architectures ◽  
Architecture Exploration ◽  
Heat Loads

High-performance cooling is often necessary for thermal management of high power density systems. However, human intuition and experience may not be adequate to identify optimal thermal management designs as systems increase in size and complexity. This article presents an architecture exploration framework for a class of single-phase cooling systems. This class is specified as architectures with multiple cold plates in series or parallel and a single fluid split and junction. Candidate architectures are represented using labeled rooted tree graphs. Dynamic models are automatically generated from these trees using a graph-based thermal modeling framework. Optimal performance is determined by solving an appropriate fluid flow distribution problem, handling temperature constraints in the presence of exogenous heat loads. Rigorous case studies are performed in simulation, with components subject to heterogeneous heat loads and temperature constraints. Results include optimization of thermal endurance for an enumerated set of 4051 architectures. The framework is also applied to identify cooling system architectures capable of steady-state operation under a given loading.

Optimal Flow Control and Single Split Architecture Exploration for Fluid-Based Thermal Management

2018 ◽  
Author(s):  
Satya R. T. Peddada ◽  
Daniel R. Herber ◽  
Herschel C. Pangborn ◽  
Andrew G. Alleyne ◽  
James T. Allison
Keyword(s):  
Flow Control ◽  
Thermal Management ◽  
High Performance ◽  
Dynamic Models ◽  
Cooling System ◽  
Rooted Tree ◽  
Modeling Framework ◽  
System Architectures ◽  
Tree Graphs ◽  
Heat Loads

High-performance cooling is often necessary for thermal management of high power density systems. Both human intuition and vast experience may not be adequate to identify optimal thermal management designs as systems increase in size and complexity. This paper presents a design framework supporting comprehensive exploration of a class of single phase fluid-based cooling architectures. The candidate cooling system architectures are represented using labeled rooted tree graphs. Dynamic models are automatically generated from these trees using a graph-based thermal modeling framework. Optimal performance is determined by solving an appropriate fluid flow control problem, handling temperature constraints in the presence of exogenous heat loads. Rigorous case studies are performed in simulation, with components having variable sets of heat loads and temperature constraints. Results include optimization of thermal endurance for an enumerated set of 4,051 architectures. In addition, cooling system architectures capable of steady-state operation under a given loading are identified.

Electronics Thermal Management Using Advanced Hybrid Two-Phase Loop Technology

2007 ◽  
Author(s):  
Chanwoo Park ◽  
Aparna Vallury ◽  
Jon Zuo ◽  
Jeffrey Perez ◽  
Paul Rogers
Keyword(s):  
Thermal Management ◽  
High Performance ◽  
Cooling System ◽  
Active Flow Control ◽  
Heat Pipes ◽  
High Heat ◽  
Heat Fluxes ◽  
Significant Advance ◽  
Two Phase ◽  
Phase Loop

The paper discusses an advanced Hybrid Two-Phase Loop (HTPL) technology for electronics thermal management. The HTPL combined active mechanical pumping with passive capillary pumping realizing a reliable yet high performance cooling system. The evaporator developed for the HTPL used 3-dimensional metallic wick structures to enhance boiling heat transfer by passive capillary separation of liquid and vapor phases. Through the testing using various prototype hybrid loops, it was demonstrated that the hybrid loops were capable of removing high heat fluxes from multiple heat sources with large surface areas up to 135cm2 and 10kW heat load. Because of the passive capillary phase separation, the hybrid loop operation didn’t require any active flow control of the liquid in the evaporator, even at highly transient and asymmetrical heat inputs between the evaporators. These results represent the significant advance over state-of-the-art heat pipes, loop heat pipes and evaporative spray cooling devices in terms of performance, robustness and simplicity.

Enhancement of Condensation Heat Transfer in Micro Systems

2009 ◽  
Author(s):  
Atsushi Tokunaga ◽  
Gyoko Nagayama ◽  
Takaharu Tsuruta
Keyword(s):  
Heat Transfer ◽  
Thermal Management ◽  
High Performance ◽  
Cooling System ◽  
High Vacuum ◽  
Condensation Heat Transfer ◽  
Heat Diffusion ◽  
High Heat Flux ◽  
Dropwise Condensation ◽  
Micro Systems

Thermal management becomes a serious concern in computer system. CPU chips are placed into small spaces with difficulty in heat diffusion. This promotes many challenges in the field of thermal management of electronics to maintain the desirable operating temperature. In order to realize the enhancement of dissipation of high heat flux from electronic components, a lot of investigations have been carried out on new cooling technology using phase change phenomena. Since the micro condenser is required in the cooling system, we are directing our attention to the enhancement of condensation heat transfer in the micro system. This study focuses on high performance of dropwise condensation heat transfer due to its small conduction resistance. In the micro systems, the interface phenomena play an important role in heat transfer. We have done dropwise condensation experiments in a high vacuum chamber system to get precise information about the vapor-liquid interface transport phenomena. Surface temperature transients are measured directly with the thin film thermocouples fabricated on the condensing surface.

scholarly journals Numerical Evaluation of a HVAC System Based on a High-Performance Heat Transfer Fluid

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3298
Author(s):  
Gianpiero Colangelo ◽  
Brenda Raho ◽  
Marco Milanese ◽  
Arturo de Risi
Keyword(s):  
Heat Transfer ◽  
High Performance ◽  
Cooling System ◽  
Electrical Energy ◽  
Simulation Software ◽  
Heat Transfer Fluid ◽  
Hvac System ◽  
Dynamic Simulations ◽  
Heating And Cooling ◽  
The University

Nanofluids have great potential to improve the heat transfer properties of liquids, as demonstrated by recent studies. This paper presents a novel idea of utilizing nanofluid. It analyzes the performance of a HVAC (Heating Ventilation Air Conditioning) system using a high-performance heat transfer fluid (water-glycol nanofluid with nanoparticles of Al2O3), in the university campus of Lecce, Italy. The work describes the dynamic model of the building and its heating and cooling system, realized through the simulation software TRNSYS 17. The use of heat transfer fluid inseminated by nanoparticles in a real HVAC system is an innovative application that is difficult to find in the scientific literature so far. This work focuses on comparing the efficiency of the system working with a traditional water-glycol mixture with the same system that uses Al2O3-nanofluid. The results obtained by means of the dynamic simulations have confirmed what theoretically assumed, indicating the working conditions of the HVAC system that lead to lower operating costs and higher COP and EER, guaranteeing the optimal conditions of thermo-hygrometric comfort inside the building. Finally, the results showed that the use of a nanofluid based on water-glycol mixture and alumina increases the efficiency about 10% and at the same time reduces the electrical energy consumption of the HVAC system.

scholarly journals PCM assisted heat pipe cooling system for the thermal management of an LTO cell for high-current profiles

2021 ◽  
pp. 100920
Author(s):  
Hamidreza Behi ◽  
Danial Karimi ◽  
Foad Heidari Gandoman ◽  
Mohsen Akbarzadeh ◽  
Sahar Khaleghi ◽  
...  
Keyword(s):  
Heat Pipe ◽  
Thermal Management ◽  
Cooling System ◽  
High Current

Perimeter Cooling Unit and Localized Row-Based Cooling Unit Transient Air Flow Effects Modeling and Characterization in Data Centers

2015 ◽  
Author(s):  
Tianyi Gao ◽  
James Geer ◽  
Bahgat G. Sammakia ◽  
Russell Tipton ◽  
Mark Seymour
Keyword(s):  
Thermal Management ◽  
Data Center ◽  
Data Centers ◽  
Cooling System ◽  
Air Flow ◽  
Cooling Systems ◽  
Dynamic Thermal Management ◽  
Hybrid Cooling ◽  
Cooling Unit ◽  
Cooling Air

Cooling power constitutes a large portion of the total electrical power consumption in data centers. Approximately 25%∼40% of the electricity used within a production data center is consumed by the cooling system. Improving the cooling energy efficiency has attracted a great deal of research attention. Many strategies have been proposed for cutting the data center energy costs. One of the effective strategies for increasing the cooling efficiency is using dynamic thermal management. Another effective strategy is placing cooling devices (heat exchangers) closer to the source of heat. This is the basic design principle of many hybrid cooling systems and liquid cooling systems for data centers. Dynamic thermal management of data centers is a huge challenge, due to the fact that data centers are operated under complex dynamic conditions, even during normal operating conditions. In addition, hybrid cooling systems for data centers introduce additional localized cooling devices, such as in row cooling units and overhead coolers, which significantly increase the complexity of dynamic thermal management. Therefore, it is of paramount importance to characterize the dynamic responses of data centers under variations from different cooling units, such as cooling air flow rate variations. In this study, a detailed computational analysis of an in row cooler based hybrid cooled data center is conducted using a commercially available computational fluid dynamics (CFD) code. A representative CFD model for a raised floor data center with cold aisle-hot aisle arrangement fashion is developed. The hybrid cooling system is designed using perimeter CRAH units and localized in row cooling units. The CRAH unit supplies centralized cooling air to the under floor plenum, and the cooling air enters the cold aisle through perforated tiles. The in row cooling unit is located on the raised floor between the server racks. It supplies the cooling air directly to the cold aisle, and intakes hot air from the back of the racks (hot aisle). Therefore, two different cooling air sources are supplied to the cold aisle, but the ways they are delivered to the cold aisle are different. Several modeling cases are designed to study the transient effects of variations in the flow rates of the two cooling air sources. The server power and the cooling air flow variation combination scenarios are also modeled and studied. The detailed impacts of each modeling case on the rack inlet air temperature and cold aisle air flow distribution are studied. The results presented in this work provide an understanding of the effects of air flow variations on the thermal performance of data centers. The results and corresponding analysis is used for improving the running efficiency of this type of raised floor hybrid data centers using CRAH and IRC units.

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