Hot Spot Cooling Using Recycled Energy

2007 ◽  
Author(s):  
Chien Ouyang ◽  
Kenny Gross ◽  
Ali Heydari
Keyword(s):  
Energy Efficiency ◽  
Solid State ◽  
Waste Heat ◽  
Hot Spot ◽  
Thermal Gradients ◽  
Novel Approach ◽  
State Technique ◽  
Spot Cooling ◽  
Wasted Energy

The paper describes a novel approach for achieving enhanced energy efficiency for computer servers. The paper teaches a novel solid-state technique and apparatus for recycling waste heat from chip packages and turning that wasted energy into hot-spot cooling for other IC packages in the same server. This approach brings the combined advantages of enhanced energy efficiency while smoothing out the spatial and temporal thermal gradients, thereby yielding better long term reliability for multiple-chip enterprise servers.

Optimization of a Pyroelectric Energy Converter for Harvesting Waste Heat

2010 ◽  
Author(s):  
Ashcon Navid ◽  
Damien Vanderpool ◽  
Abubakarr Bah ◽  
Laurent Pilon
Keyword(s):  
Energy Efficiency ◽  
Power Density ◽  
Silicone Oil ◽  
Waste Heat ◽  
Electrical Power ◽  
Optimum Operating ◽  
Maximum Efficiency ◽  
Working Fluid ◽  
Energy Converter ◽  
Novel Approach

Pyroelectric energy conversion offers a novel approach for directly converting waste heat into electricity. This paper reports numerical simulations of a prototypical pyroelectric energy converter. The two-dimensional mass, momentum, and energy equations were solved to predict the local and time-dependent pressure, velocity, and temperature. Then, the heat input, pump power, and electrical power generated were estimated, along with the thermodynamic energy efficiency of the device. It was established that reducing the length of the device and the viscosity of the working fluid improved the energy efficiency and power density by increasing the optimum operating frequency of the device. Results show that a maximum efficiency of 5.2% at 0.5 Hz corresponding to 55.4% of the Carnot efficiency between 145 and 185°C can be achieved when using commercial 1.5 cst silicone oil. The maximum power density was found to be 38.4 W/l of pyroelectric material.

Hot Spot Cooling and Harvesting CPU Waste Heat Using Thermoelectric Modules

2014 ◽  
Author(s):  
Soochan Lee ◽  
Patrick E. Phelan ◽  
Carole-Jean Wu
Keyword(s):  
Energy Consumption ◽  
Hot Spots ◽  
Waste Heat ◽  
Hot Spot ◽  
Heat Energy ◽  
High Heat Flux ◽  
Air Cooling ◽  
Thermoelectric Coolers ◽  
Thermoelectric Modules ◽  
Spot Cooling

The increasing integration of high performance processors and dense circuits in current computing devices has produced high heat flux in localized areas (hot spots) that limits their performance and reliability. To control the hot spots on a CPU, many researchers have focused on active cooling methods such as thermoelectric coolers (TECs) to avoid thermal emergencies. This paper presents the optimized thermoelectric modules on top of the CPU combined with a conventional air-cooling device to reduce the hot spot temperature and at the same time harvest waste heat energy generated by the CPU. To control the temperature of the hot spots, we attach small-sized TECs to the CPU and use thermoelectric generators (TEGs) placed on the rest of the CPU to convert waste heat energy into electricity. This study investigates design alternatives with an analytical model considering the non-uniform temperature distribution based on two-node thermal networks. The results indicate that we are able to attain more energy from the TEGs than energy consumption for running the TECs. In other words, we can allow the harvested heat energy to be reused to power other components and reduce hot spots simultaneously. Overall, the idea of simultaneous hot spot cooling and waste heat harvesting using thermoelectric modules on a CPU is a promising method to control the problem of heat generation and to reduce energy consumption in a computing device.

scholarly journals Long-Term IoT-Based Maternal Monitoring: System Design and Evaluation

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2281
Author(s):  
Fatemeh Sarhaddi ◽  
Iman Azimi ◽  
Sina Labbaf ◽  
Hannakaisa Niela-Vilén ◽  
Nikil Dutt ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Maternal Health ◽  
Pregnant Women ◽  
Health Monitoring ◽  
Quality Care ◽  
Well Being ◽  
Pregnancy And Postpartum ◽  
Comprehensive Framework ◽  
Specific Health

Pregnancy is a unique time when many mothers gain awareness of their lifestyle and its impacts on the fetus. High-quality care during pregnancy is needed to identify possible complications early and ensure the mother’s and her unborn baby’s health and well-being. Different studies have thus far proposed maternal health monitoring systems. However, they are designed for a specific health problem or are limited to questionnaires and short-term data collection methods. Moreover, the requirements and challenges have not been evaluated in long-term studies. Maternal health necessitates a comprehensive framework enabling continuous monitoring of pregnant women. In this paper, we present an Internet-of-Things (IoT)-based system to provide ubiquitous maternal health monitoring during pregnancy and postpartum. The system consists of various data collectors to track the mother’s condition, including stress, sleep, and physical activity. We carried out the full system implementation and conducted a real human subject study on pregnant women in Southwestern Finland. We then evaluated the system’s feasibility, energy efficiency, and data reliability. Our results show that the implemented system is feasible in terms of system usage during nine months. We also indicate the smartwatch, used in our study, has acceptable energy efficiency in long-term monitoring and is able to collect reliable photoplethysmography data. Finally, we discuss the integration of the presented system with the current healthcare system.

Investigation of On-Chip Hot Spot Cooling Using Microchannel Heat Sink

2013 ◽  
Vol 455 ◽  
pp. 466-469
Author(s):  
Yun Chuan Wu ◽  
Shang Long Xu ◽  
Chao Wang
Keyword(s):  
Heat Flux ◽  
Heat Sink ◽  
Hot Spots ◽  
Hot Spot ◽  
High Heat ◽  
High Heat Flux ◽  
Microchannel Heat Sink ◽  
Three Dimensional Model ◽  
Spot Cooling ◽  
On Chip

With the increase of performance demands, the nonuniformity of on-chip power dissipation becomes greater, causing localized high heat flux hot spots that can degrade the processor performance and reliability. In this paper, a three-dimensional model of the copper microchannel heat sink, with hot spot heating and background heating on the back, was developed and used for numerical simulation to predict the hot spot cooling performance. The hot spot is cooled by localized cross channels. The pressure drop, thermal resistance and effects of hot spot heat flux and fluid flow velocity on the cooling of on-chip hot spots, are investigated in detail.

scholarly journals Approximate models for the lattice thermal conductivity of alloy thermoelectrics

2021 ◽  
Author(s):  
Jonathan Skelton
Keyword(s):  
Thermal Conductivity ◽  
Energy Efficiency ◽  
Lattice Thermal Conductivity ◽  
Waste Heat ◽  
Seebeck Effect ◽  
Thermoelectric Generators ◽  
Approximate Models

Thermoelectric generators (TEGs) convert waste heat to electricity and are a leading contender for improving energy efficiency at a range of scales. Ideal TE materials show a large Seebeck effect,...

Development of a Performance-Related Framework for Asphalt Mixture Design for the Illinois Tollway

2021 ◽  
pp. 036119812110148
Author(s):  
Behnam Jahangiri ◽  
Punyaslok Rath ◽  
Hamed Majidifard ◽  
William G. Buttlar
Keyword(s):  
Asphalt Mixture ◽  
Field Performance ◽  
Compact Tension ◽  
T Test ◽  
Novel Approach ◽  
Final Adjustment ◽  
Development And Validation ◽  
High Degree ◽  
Selection Of

Various agencies have begun to research and introduce performance-related specifications (PRS) for the design of modern asphalt paving mixtures. The focus of most recent studies has been directed toward simplified cracking test development and evaluation. In some cases, development and validation of PRS has been performed, building on these new tests, often by comparison of test values to accelerated pavement test studies and/or to limited field data. This study describes the findings of a comprehensive research project conducted at Illinois Tollway, leading to a PRS for the design of mainline and shoulder asphalt mixtures. A novel approach was developed, involving the systematic establishment of specification requirements based on: 1) selection of baseline values based on minimally acceptable field performance thresholds; 2) elevation of thresholds to account for differences between short-term lab aging and expected long-term field aging; 3) further elevation of thresholds to account for variability in lab testing, plus variability in the testing of field cores; and 4) final adjustment and rounding of thresholds based on a consensus process. After a thorough evaluation of different candidate cracking tests in the course of the project, the Disk-shaped Compact Tension—DC(T)—test was chosen to be retained in the Illinois Tollway PRS and to be presented in this study for the design of crack-resistant mixtures. The DC(T) test was selected because of its high degree of correlation with field results and its excellent repeatability. Tailored Hamburg rut depth and stripping inflection point thresholds were also established for mainline and shoulder mixes.

scholarly journals Design of a Database of Case Studies and Technologies to Increase the Diffusion of Low-Temperature Waste Heat Recovery in the Industrial Sector

2021 ◽  
Vol 13 (9) ◽  
pp. 5223
Author(s):  
Miriam Benedetti ◽  
Daniele Dadi ◽  
Lorena Giordano ◽  
Vito Introna ◽  
Pasquale Eduardo Lapenna ◽  
...  
Keyword(s):  
Low Temperature ◽  
Case Studies ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Industrial Sector ◽  
Implementation Rate ◽  
Depth Analysis ◽  
Technology Market

The recovery of waste heat is a fundamental means of achieving the ambitious medium- and long-term targets set by European and international directives. Despite the large availability of waste heat, especially at low temperatures (<250 °C), the implementation rate of heat recovery interventions is still low, mainly due to non-technical barriers. To overcome this limitation, this work aims to develop two distinct databases containing waste heat recovery case studies and technologies as a novel tool to enhance knowledge transfer in the industrial sector. Through an in-depth analysis of the scientific literature, the two databases’ structures were developed, defining fields and information to collect, and then a preliminary population was performed. Both databases were validated by interacting with companies which operate in the heat recovery technology market and which are possible users of the tools. Those proposed are the first example in the literature of databases completely focused on low-temperature waste heat recovery in the industrial sector and able to provide detailed information on heat exchange and the technologies used. The tools proposed are two key elements in supporting companies in all the phases of a heat recovery intervention: from identifying waste heat to choosing the best technology to be adopted.

A Novel Approach Towards Cementing Design Achieved Significant Improvement in Long Term Zonal Isolation

2019 ◽  
Author(s):  
Ala Suleiman ◽  
Bashar Hilal ◽  
Phalgun Paila ◽  
Sahir Abdelhadi ◽  
Khalid Alwahedi ◽  
...  
Keyword(s):  
Novel Approach ◽  
Zonal Isolation

scholarly journals Edible Energy Production and Energy Return on Investment—Long-Term Analysis of Global Changes

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1011
Author(s):  
Bartłomiej Bajan ◽  
Joanna Łukasiewicz ◽  
Agnieszka Poczta-Wajda ◽  
Walenty Poczta
Keyword(s):  
Energy Efficiency ◽  
Return On Investment ◽  
Food Production ◽  
Energy Production ◽  
Crop Production ◽  
Fossil Fuels ◽  
Animal Production ◽  
Global Changes ◽  
Energy Return On Investment

The projected increase in the world’s population requires an increase in the production of edible energy that would meet the associated increased demand for food. However, food production is strongly dependent on the use of energy, mainly from fossil fuels, the extraction of which requires increasing input due to the depletion of the most easily accessible deposits. According to numerous estimations, the world’s energy production will be dependent on fossil fuels at least to 2050. Therefore, it is vital to increase the energy efficiency of production, including food production. One method to measure energy efficiency is the energy return on investment (EROI), which is the ratio of the amount of energy produced to the amount of energy consumed in the production process. The literature lacks comparable EROI calculations concerning global food production and the existing studies only include crop production. The aim of this study was to calculate the EROI of edible crop and animal production in the long term worldwide and to indicate the relationships resulting from its changes. The research takes into account edible crop and animal production in agriculture and the direct consumption of fossil fuels and electricity. The analysis showed that although the most underdeveloped regions have the highest EROI, the production of edible energy there is usually insufficient to meet the food needs of the population. On the other hand, the lowest EROI was observed in highly developed regions, where production ensures food self-sufficiency. However, the changes that have taken place in Europe since the 1990s indicate an opportunity to simultaneously reduce the direct use of energy in agriculture and increase the production of edible energy, thus improving the EROI.

scholarly journals Energy and Exergy Efficiency Analysis of Fluid Flow and Heat Transfer in Sinter Vertical Cooler

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4522
Author(s):  
Zude Cheng ◽  
Haitao Wang ◽  
Junsheng Feng ◽  
Yongfang Xia ◽  
Hui Dong
Keyword(s):  
Heat Transfer ◽  
Energy Efficiency ◽  
Fluid Flow ◽  
Waste Heat ◽  
Exergy Efficiency ◽  
Inlet Temperature ◽  
Operational Parameters ◽  
Flow And Heat Transfer ◽  
Maximum Value ◽  
Energy And Exergy

In order to fully understand the energy and exergy transfer processes in sinter vertical coolers, a simulation model of the fluid flow and heat transfer in a vertical cooler was established, and energy and exergy efficiency analyses of the gas–solid heat transfer in a vertical cooler were conducted in detail. Based on the calculation method of the whole working condition, the suitable operational parameters of the vertical cooler were obtained by setting the net exergy efficiency in the vertical cooler as the indicator function. The results show that both the quantity of sinter waste heat recovery (SWHR) and energy efficiency increased as the air flow rate (AFR) increased, and they decreased as the air inlet temperature (AIT) increased. The increase in the sinter inlet temperature (SIT) resulted in an increase in the quantity of SWHR and a decrease in energy efficiency. The air net exergy had the maximum value as the AFR increased, and it only increased monotonically as the SIT and AIT increased. The net exergy efficiency reached the maximum value as the AFR and AIT increased, and the increase in the SIT only resulted in a decrease in the net exergy efficiency. When the sinter annual production of a 360 m2 sintering machine was taken as the processing capacity of the vertical cooler, the suitable operational parameters of the vertical cooler were 190 kg/s for the AFR, and 353 K for the AIT.

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