Design of Passive Two-Phase Thermosyphons for Server Cooling

2019 ◽  
Author(s):  
Raffaele L. Amalfi ◽  
Jackson B. Marcinichen ◽  
John R. Thome ◽  
Filippo Cataldo
Keyword(s):  
Energy Consumption ◽  
Total Energy ◽  
Energy Efficient ◽  
High Efficiency ◽  
Cooling System ◽  
Inlet Temperature ◽  
Air Cooling ◽  
Annual Growth Rate ◽  
Total Energy Consumption ◽  
Two Phase

Abstract The main objective of this paper is to utilize an improved version of the simulator presented at InterPACK 2017 to design a thermosyphon system for energy-efficient heat removal from 2-U servers used in high-power datacenters. Currently, between 25% and 45% of the total energy consumption of a datacenter (this number does not include the energy required to drive the fans at the server-level) is dedicated to cooling, and with a predicted annual growth rate of about 15% (or higher) coupled with the plan of building numerous new datacenters to handle the “big data” storage and processing demands of emerging 5G networks, artificial intelligence, electrical vehicles, etc., the development of novel, high efficiency cooling technologies becomes extremely important for curbing the use of energy in datacenters. Notably, going from air cooling to two-phase cooling, not only enables the possibility to handle the ever higher heat fluxes and heat loads of new servers, but it also provides an energy-efficient solution to be implemented for all servers of a datacenter to reduce the total energy consumption of the entire cooling system. In that light, a pseudo-chip with a footprint area of 4 × 4 cm2 and a maximum power dissipation of 300 W (corresponding heat flux of about 19 W/cm2), will be assumed as a target design for our novel thermosyphon-based cooling system. The simulator will be first validated against an independent database and then used to find the optimal design of the chip’s thermosyphon. The results demonstrate the capability of this simulator to model all of the thermosyphon’s components (evaporator, condenser, riser and downcomer) together with overall thermal performance and creation of operational maps. Additionally, the simulator is used here to design two types of passive two-phase systems, an air- and a liquid-cooled thermosyphon, which will be compared in terms of thermal-hydraulic performance. Finally, the simulator will be used to perform a sensitivity analysis on the secondary coolant side conditions (inlet temperature and mass flow rate) to evaluate their effect on the system performance.

Analysis of Running Energy Consumption of Fresh Air Cooling Systems

Solar Energy ◽  
2005 ◽  
Author(s):  
Jianing Zhao ◽  
Jun Guo ◽  
Weimeng Sun
Keyword(s):  
Energy Consumption ◽  
Total Energy ◽  
Cooling System ◽  
Air Cooling ◽  
Total Energy Consumption ◽  
Cooling Systems ◽  
Variable Air Volume ◽  
Air Volume ◽  
Air System ◽  
Different Seasons

Utilization of renewable energy becomes more and more attractive and crucial for sustainable buildings. A cooling system, using outdoor fresh air and combining with the conventional all-air system or running along during different seasons, is discussed in this study. Running energy consumption of this system is analyzed by a mathematical model using the Genetic Algorithm (GA) combined with the traditional Lagrange method. To evaluate and apply this new system, energy consumption of the chiller unit, water and air sub-systems, as well as the total energy consumption of such a system is compared with that of the conventional all-air system. Consequently, the total energy consumption is selected as the criterion of energy efficiency. The results show that the cooling system bears considerably energy efficient, and that it reduces energy consumption at least 14% and 12%, compared with the constant air volume and variable air volume system, respectively.

Characterization of an Isolated Hybrid Cooled Server With Failure Scenarios Using Warm Water Cooling

2017 ◽  
Author(s):  
Uschas Chowdhury ◽  
Manasa Sahini ◽  
Ashwin Siddarth ◽  
Dereje Agonafer ◽  
Steve Branton
Keyword(s):  
Energy Consumption ◽  
Data Centers ◽  
Cooling System ◽  
Warm Water ◽  
Alternative Methods ◽  
Inlet Temperature ◽  
Cooling Efficiency ◽  
Water Cooling ◽  
Liquid Cooling ◽  
Total Energy Consumption

Modern day data centers are operated at high power for increased power density, maintenance, and cooling which covers almost 2 percent (70 billion kilowatt-hours) of the total energy consumption in the US. IT components and cooling system occupy the major portion of this energy consumption. Although data centers are designed to perform efficiently, cooling the high-density components is still a challenge. So, alternative methods to improve the cooling efficiency has become the drive to reduce the cooling cost. As liquid cooling is more efficient for high specific heat capacity, density, and thermal conductivity, hybrid cooling can offer the advantage of liquid cooling of high heat generating components in the traditional air-cooled servers. In this experiment, a 1U server is equipped with cold plate to cool the CPUs while the rest of the components are cooled by fans. In this study, predictive fan and pump failure analysis are performed which also helps to explore the options for redundancy and to reduce the cooling cost by improving cooling efficiency. Redundancy requires the knowledge of planned and unplanned system failures. As the main heat generating components are cooled by liquid, warm water cooling can be employed to observe the effects of raised inlet conditions in a hybrid cooled server with failure scenarios. The ASHRAE guidance class W4 for liquid cooling is chosen for our experiment to operate in a range from 25°C – 45°C. The experiments are conducted separately for the pump and fan failure scenarios. Computational load of idle, 10%, 30%, 50%, 70% and 98% are applied while powering only one pump and the miniature dry cooler fans are controlled externally to maintain constant inlet temperature of the coolant. As the rest of components such as DIMMs & PCH are cooled by air, maximum utilization for memory is applied while reducing the number fans in each case for fan failure scenario. The components temperatures and power consumption are recorded in each case for performance analysis.

scholarly journals EVALUATION OF ENERGY-EFFICIENT RETROFIT POTENTIAL FOR GOVERNMENT OFFICES IN INDIA

2021 ◽  
Vol 6 (2) ◽  
pp. 03-17
Author(s):  
Gazal Dandia ◽  
◽  
Pratheek Sudhakaran ◽  
Chaitali Basu ◽  
◽  
...  
Keyword(s):  
Energy Consumption ◽  
Total Energy ◽  
Energy Efficient ◽  
Energy Demand ◽  
Energy Savings ◽  
High Energy ◽  
Payback Period ◽  
Total Energy Consumption ◽  
The Cost

Introduction: High energy consumption by buildings is a great threat to the environment and one of the major causes of climate change. With a population of 1.4 billion people and one of the fastest-growing economies in the world, India is extremely vital for the future of global energy markets. The energy demand for construction activities continues to rise and it is responsible for over one-third of global final energy consumption. Currently, buildings in India account for 35% of total energy consumption and the value is growing by 8% annually. Around 11% of total energy consumption are attributed to the commercial sector. Energy-efficient retrofitting of the built environments created in recent decades is a pressing urban challenge. Presently, most energy-efficient retrofit projects focus mainly on the engineering aspects. In this paper, we evaluate various retrofitting options, such as passive architectural interventions, active technological interventions, or a combination of both, to create the optimum result for the selected building. Methods: Based on a literature study and case examples, we identified various energy-efficient retrofit measures, and then examined and evaluated those as applied to the case study of Awas Bhawan (Rajasthan Housing Board Headquarters), Jaipur, India. For the evaluation, we developed a simulation model using EQuest for each energy measure and calculated the resultant energy savings. Then, based on the cost of implementation and the cost of energy saved, we calculated the payback period. Finally, an optimum retrofit solution was formulated with account for the payback period and ease of installation. Results and discussion: The detailed analysis of various energy-efficient retrofit measures as applied to the case study indicates that the most feasible options for retrofit resulting in optimum energy savings with short payback periods include passive architecture measures and equipment upgrades.

scholarly journals Impact of Fan Airflow of IT Equipment on Thermal Environment and Energy Consumption of a Data Center

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6166
Author(s):  
Naoki Futawatari ◽  
Yosuke Udagawa ◽  
Taro Mori ◽  
Hirofumi Hayama
Keyword(s):  
Energy Consumption ◽  
Total Energy ◽  
Data Center ◽  
Air Conditioning ◽  
Thermal Environment ◽  
Operating Efficiency ◽  
Inlet Temperature ◽  
Total Energy Consumption ◽  
Air Supply ◽  
Machine Room

Energy-saving in regard to heating, ventilation, and air-conditioning (HVAC) in data centers is strongly required. Therefore, to improve the operating efficiency of the cooling equipment and extend the usage time of the economizer used for cooling information-technology equipment (ITE) in a data center, it is often the case that a high air-supply temperature within the range in which the ITE can be sufficiently cooled is selected. In the meantime, it is known that when the ambient temperature of the ITE rises, the speed of the built-in cooling fan increases. Acceleration of the built-in fan is thought to affect the cooling performance and energy consumption of the data center. Therefore, a method for predicting the temperature of a data center—which simply correlates supply-air temperature with ITE inlet temperature by utilizing existing indicators, such as air-segregation efficiency (ASE)—is proposed in this study. Moreover, a method for optimizing the total energy consumption of a data center is proposed. According to the prediction results obtained under the assumption of certain computer-room air-conditioning (CRAC) conditions, by lowering the ITE inlet temperature from 27 °C to 18 °C, the total energy consumption of the machine room is reduced by about 10%.

scholarly journals Energy-Efficient Driving Strategies for Multi-Train by Optimization and Update Speed Profiles Considering Transmission Losses of Regenerative Energy

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3573 ◽  
Author(s):  
Chen ◽  
Xiao ◽  
Sun ◽  
Wang ◽  
Jin ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Total Energy ◽  
Energy Efficient ◽  
Urban Rail Transit ◽  
Electrical Network ◽  
Optimization Strategy ◽  
Total Energy Consumption ◽  
Optimal Control Strategy ◽  
Train Speed ◽  
Regenerative Energy

This paper aims at minimizing the total energy consumption of multi-train in an urban rail transit (URT) system by optimizing and updating speed profiles considering regenerative braking power losses on the catenary. To make full use of regenerative energy and decrease traction energy consumption simultaneously, energy-efficient control strategies of multi-train and a corresponding solution method are proposed. The running process of multi-train is divided into several sections based on passenger stations. Speed profiles of each train in each section are collaboratively optimized by searching only one transition point from the optimized single-train speed profile, which can be worked out by searching the switching point of coasting mode, and the optimized multi-train speed profiles are updated based on departure orders of trains. Moreover, an electrical network model is established to analyze energy flows, and dynamic losses of recovered regenerative energy on the line can be calculated. Besides, an improved optimization strategy of multi-train, which contains seven motion phases, is presented for steep slope. Simulation results based on Guangzhou Metro Line 8 verify the effectiveness of the proposed methods. Total energy consumption of optimized multi-train can be decreased by 6.95% compared with multi-train adopted single-train optimal control strategy, and the energy-saving rate of 21.08% can be achieved compared with the measured data by drivers under same trip time. In addition, the influence of departure interval on total energy consumption is analyzed and the optimal departure interval can be obtained.

Energy Flow Analysis and Energy Conservation and Emission Reduction in Sichuan Province, China

2014 ◽  
Vol 521 ◽  
pp. 819-824
Author(s):  
Wei Liu ◽  
Xi Yu Feng ◽  
Guan Huang ◽  
Han Qing Huan
Keyword(s):  
Growth Rate ◽  
Energy Consumption ◽  
Energy Conservation ◽  
Total Energy ◽  
Emission Reduction ◽  
Sichuan Province ◽  
Average Annual Growth Rate ◽  
Annual Growth Rate ◽  
Total Energy Consumption ◽  
Pollutants Emission

Based on the relative data and materials, the energy flowchart of Sichuan province in 2008 was drew at first, then the energy input, output, consumption, corresponding pollutants emission of Sichuan province from 2000 to 2008 were analysed simultaneously. The results show that the total energy consumption reaches up to about 15144.96 tons of standard coal in 2008, the average annual growth rate is 8.42%. Coal and non-fossil energy consumption accounts for 65.35% and 8.44% of total energy consumption respectively. SO2 emissions decreases by an average annual rate of 4.03% since 2005, but NOX and CO2 emissions increases with average annual growth rate of 6.58% and 8.37% respectively. In addition, the energy consumption and pollutants emission of Sichuan province during "the 12th Five-Year Plan" are predicted and analysed within different scenario, then the development plan is proposed. Finally, suggestions of energy conservation and emission reduction in Sichuan province are proposed.

Investigation on the Effect of Different Channel Geometries of Thermal Wheel for Energy Transfer Efficiency

2021 ◽  
Author(s):  
A.M.C.K. Polgolla ◽  
◽  
H.M.D.P. Herath ◽  
M.D.A. Wickramasinghe ◽  
M.A. Wijewardane ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Total Energy ◽  
Pressure Loss ◽  
Energy Savings ◽  
High Efficiency ◽  
The United States ◽  
Total Energy Consumption ◽  
Final Energy Consumption ◽  
Air Conditioning Systems ◽  
Air Streams

Inside buildings, heating, ventilation, and air conditioning systems are utilized to provide a comfortable environment. However, they account for a significant percentage of overall total energy consumption: in the United States, they account for about 50% of building final energy consumption and 20% of total energy consumption. [1]. The installation of a heat exchanger between the exhaust and fresh air streams is critical, owing to the significant energy savings. [2], [3]. Thermal wheels have recently gotten a lot of attention because of their high efficiency and low-pressure loss when compared to other energy recovery solutions [4]. The goal of this research is to give a comprehensive study and optimization of Thermal wheel design, with the goal of enhancing sensible effectiveness while reducing pressure loss based on channel shape.

Environmental and Energy Assessment of a Family House

2017 ◽  
Author(s):  
Peter Turcsanyi ◽  
Anna Sedlakova ◽  
Eva Kridlova Burdova ◽  
Silvia Vilcekova
Keyword(s):  
Energy Consumption ◽  
Total Energy ◽  
Energy Efficient ◽  
Slovak Republic ◽  
Simulation Software ◽  
Point Of View ◽  
Diagnostic Methods ◽  
Total Energy Consumption ◽  
Energy Efficient Building ◽  
Family House

Term energy efficient building is well know from year 1991, when Austrian physicist Dr. Feist designed and built first passive house, using current physical and practical knowledge. In the next 25 years buildings using principles of energy efficient design have changed dramatically. In a good way. It is mandatory for Slovak Republic as a part of European Union to act according European parliament directives. One of directives concerns lowering total energy consumption and emissions in the building sector – Directive 2010/31/EU on Energy performance of buildings, also known as Directive “20-20-20”. According to this directive, Slovak Republic has agreed to lower total energy consumption in building industry by 20% until year 2020. Plan on lowering total energy consumption has affected creation of new – technical and energy efficient building materials with emphasis on environmental load. It this paper, ultra-low-energy family house located in Košice, Slovakia was assessed from environmental and energy point of view. With help on modern diagnostic methods and thermo- physical simulation software DesignBuilder, we will virtually evaluate energy need of house throughout the reference year, and indoor quality from the environmental point of view, such as CO2 levels and bounded energy using LCA method.

Calculation of Energy Consumption for Large Generator Cooling System

2014 ◽  
Vol 953-954 ◽  
pp. 1445-1448 ◽  
Author(s):  
Wei Huang ◽  
Zi Yu Wu ◽  
Jian Hong Guo ◽  
Hai Feng Wang ◽  
Guo Biao Gu ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Total Energy ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Total Energy Consumption ◽  
Cooling Systems ◽  
Energy Consuming ◽  
Low Efficiency ◽  
Cooling Methods ◽  
Water Hydrogen

Cooling systems is significance for the structure and energy-saving operation of generator. Different cooling methods affects the efficiency and energy losing of generator. In order to quantitatively calculate the energy consumption of cooling system, this paper proposed three energy consumption indexes for large generator. Energy consuming of a dual inner water cooled generator, a water-hydrogen-hydrogen cooled generator and an evaporative cooling generator were calculated according to the proposed method. The results indicate that the total energy consumption of dual inner water cooled generator is maximum because of its low efficiency, and evaporative cooling generator effectively reduces energy consumption.

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