Thermofluid Design of Energy Efficient and Compact Heat Sinks

2003 ◽  
Author(s):  
Kazuaki Yazawa ◽  
Gary L. Solbrekken ◽  
Avram Bar-Cohen
Keyword(s):  
Heat Sink ◽  
Energy Efficient ◽  
Cooling System ◽  
Heat Sinks ◽  
Air Cooling ◽  
Notebook Computers ◽  
Air Cooling System ◽  
Parametric Studies ◽  
Design Optimum

A compact, energy efficient heat sink design methodology is presented for shrouded, parallel plate fins in laminar flow. The analytic model accounts for the sensible temperature rise of the air flowing between fins, convective heat transfer to the flowing stream, and conduction in the fins. To evaluate the efficiency of the air cooling system, consideration is also given to the determination of the fan pumping power. This paper focuses on the optimization of the heat sink-fan combination for energy efficiency, subject to volumetric constraints. The design optimum is found by matching the most efficient operating point of the fan with the corresponding optimum fin geometry. A series of parametric studies was completed to identify the sensitivity of the cooling solution to parametric variations. This numerically validated model has been used to visualize the parametric impact of dealing with “real world” manufacturing limitation in the development of thermal packaging solutions for notebook computers and other electronic products.

Feasibility Assessment of Air-Cooling System As an Ultimate Heat Sink of the ATOM System

2018 ◽  
Author(s):  
Doyoung Shin ◽  
Gwang Hyeok Seo ◽  
Min Wook Na ◽  
Sung Joong Kim ◽  
Yonghee Kim ◽  
...  
Keyword(s):  
Flow Rate ◽  
Heat Sink ◽  
Cooling System ◽  
Air Cooling ◽  
Primary Coolant ◽  
Final Heat ◽  
Feasibility Assessment ◽  
Environment Temperature ◽  
Air Cooling System ◽  
Atom System

Nowadays Small Modular Reactors (SMRs) have been receiving considerable attentions worldwide for potential advantages of an excellent flexibility for siting, low capital investment, and advanced safety. In Korea, a new research project has launched for the development of a conceptual design of a further advanced SMR which aims for a naturally-safe and autonomous operation, so called Autonomous Transportable On-demand reactor Module (ATOM). Major design objectives of the ATOM system are focused on the soluble boron-free (SBF) primary coolant system which enables the SMR to operate automatically in a load following mode. For the secondary system, the SCO2 power conversion cycle with air-cooling system as a final heat sink is being considered. The air-cooling system is expected to show flexible response even to extreme environmental conditions, such as a desert where utilization of cooling water is limited. The objective of this study is a feasibility assessment for applying the air-cooling system as a final heat sink of the ATOM by means of experimental work. As a 1st phase of the ATOM development, we first conducted the experiments using a typically considered primary coolant, water-steam, to verify that air flow has enough cooling capability to remove developed heat which the coolant carries. An Integrated Condensation Loop with Air-cooling System (ICLASS) experimental facility with three pressure boundaries (Steam, coolant, and air) was established. The cooling capability of the air-cooling system was evaluated by varying steam mass flow rate, coolant flow rate, and air environment temperature as experiment variables. Overall heat transfer rate by condensation was compared with numerical simulations of a 1D thermal-hydraulics analysis code, using the MARS model of the ICLASS facility.

scholarly journals An experimental investigation on the performance of a thermoelectric dehumidification system

2018 ◽  
Vol 12 (4) ◽  
pp. 4117-4126
Author(s):  
P. Rakkwamsuk ◽  
P. Paromupatham ◽  
K. Sathapornprasath ◽  
C. Lertsatitthanakorn ◽  
S. Soponronnarit
Keyword(s):  
Heat Sink ◽  
Cooling System ◽  
Test Chamber ◽  
Cooling Water ◽  
Suitable Condition ◽  
Cooling Capacity ◽  
Coefficient Of Performance ◽  
Air Cooling ◽  
Air Cooling System ◽  
Te Modules

A thermoelectric (TE) air-cooling system for dehumidifying indoor air in a building was investigated. The system was composed of 4 TE modules. The cold sides of the TE modules were fixed to an aluminum heat sink to remove moisture in the air of a test chamber of 1 m3 volume, while a heat sink with circulating cooling water at the hot sides of the TE modules was used for heat release. The effects of input electric current to the TE modules and air flow rate through the heat sink were experimentally determined. The system’s performance was evaluated using dehumidification effectiveness and coefficient of performance (COP). A suitable condition occurred at 18.5 A of current flow and 240 W of power being supplied to the TE modules with a corresponding cooling capacity of 149.5 W, which gave a dehumidification effectiveness of 0.62. Therefore, it is anticipated the proposed TE dehumidifier concept will contribute to the air conditioning system’s reduction of room humidity. 

Water-Mist-Cooled Heat Sink for Autonomous Air-Cooling System (AACS) of More Electric Aircraft (MEA)

2016 ◽  
Author(s):  
Akira Murata ◽  
Hiroshi Saito ◽  
Yoji Okita
Keyword(s):  
Heat Sink ◽  
Cooling System ◽  
Water Mist ◽  
Air Cooling ◽  
Cooling Performance ◽  
Motor Controller ◽  
Electric Aircraft ◽  
Air Cooling System ◽  
Cooling Air ◽  
More Electric Aircraft

The More Electric Aircraft (MEA) is a system architecture concept for the aircraft that reduces fuel consumption and environmental load while improving safety, reliability, and maintainability. MEA architecture replaces some of the conventional hydraulic and/or mechanical control system with electric motor-driven system, integrates system power management into the aircraft/engine controls, and optimizes the aircraft geometry by flexibly arranging the accessory devices. The primary challenge to realize the MEA concept is how to manage the heat from these additional power electronic devices. The authors’ group proposed novel cooling system, the Autonomous Air-Cooling System (AACS) which cools the power electronics of the motor devices distributed in the aircraft. In AACS, each power electronic device (e.g. motor controller) is air-cooled by heat sinks connected to compact blowers. This system is very simple and efficient since it re-uses the cabin air and needs no additional coolant. One of the key technologies which realize AACS is an efficient heat sink. In this study, at first the performance evaluation targeting a single-aisle 180-seater aircraft was performed. In the analysis, a plate-fin heat sink was adopted, and the pressure loss and heat transfer was estimated by using empirical correlations. In the analysis, the value of heat generation was assumed from power demand for each operation condition, and the required mass flow rate of cooling air was calculated so as for the enclosure temperature of the power electronics to be 80°C which was the allowable maximum temperature of the motor controller. The effect of the fin geometry on the cooling performance was also examined by varying the geometric parameters (fin height, thickness, and spacing). In order to further enhance the cooling performance without increasing the pressure loss, the water-mist injection to the cooling air flow was adopted and its effect was analytically confirmed. In addition, the effectiveness of the water-mist injection on the cooling performance was verified by performing experiments for a plate-fin heat sink manufactured by a wire electric discharge method.

scholarly journals Optimization of Air Cooling System Using Adjoint Solver Technique

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3753
Author(s):  
Grzegorz Czerwiński ◽  
Jerzy Wołoszyn
Keyword(s):  
Heat Source ◽  
Heat Sink ◽  
Cooling System ◽  
Geometric Model ◽  
Maximum Temperature ◽  
Air Cooling ◽  
Ansys Fluent ◽  
Source Temperature ◽  
Heat Source Temperature ◽  
Air Cooling System

Air cooling systems are currently the most popular and least expensive solutions to maintain a safe temperature in electronic devices. Heat sinks have been widely used in this area, allowing for an increase in the effective heat transfer surface area. The main objective of this study was to optimise the shape of the heat sink geometric model using the Adjoint Solver technique. The optimised shape in the context of minimal temperature value behind the heat sink is proposed. The effect of radiation and trapezoidal fin shape on the maximum temperature in the cooling system is also investigated. Simulation studies were performed in Ansys Fluent software using the Reynolds—averaged Navier–Stokes technique. As a result of the simulation, it turned out that not taking into account the radiation leads to an overestimation of temperatures in the system—even by 14 ∘C. It was found that as the angle and height of the fins increases, the temperature value behind the heat sink decreases and the heat source temperature increases. The best design in the context of minimal temperature value behind the heat sink from all analysed cases is obtained for heat sink with deformed fins according to iteration 14. The temperature reduction behind the heat sink by as much as 25 ∘C, with minor changes in heat source temperature, has been achieved.

scholarly journals Air circulation in a gastrointestinal light source box and endoscope in the era of SARS-CoV-2 and airborne transmission of microorganisms

2021 ◽  
Vol 09 (03) ◽  
pp. E482-E486
Author(s):  
Stanislas Chaussade ◽  
Einas Abou Ali ◽  
Rachel Hallit ◽  
Arthur Belle ◽  
Maximilien Barret ◽  
...  
Keyword(s):  
Light Source ◽  
Cooling System ◽  
Air Cooling ◽  
Airborne Transmission ◽  
Plastic Tube ◽  
Care Workers ◽  
Air Cooling System ◽  
Forced Air ◽  
Air Circulation ◽  
Closed Environment

Abstract Background and study aims The role that air circulation through a gastrointestinal endoscopy system plays in airborne transmission of microorganisms has never been investigated. The aim of this study was to explore the potential risk of transmission and potential improvements in the system. Methods We investigated and described air circulation into gastrointestinal endoscopes from Fujifilm, Olympus, and Pentax. Results The light source box contains a lamp, either Xenon or LED. The temperature of the light is high and is regulated by a forced-air cooling system to maintain a stable temperature in the middle of the box. The air used by the forced-air cooling system is sucked from the closed environment of the patient through an aeration port, located close to the light source and evacuated out of the box by one or two ventilators. No filter exists to avoid dispersion of particles outside the processor box. The light source box also contains an insufflation air pump. The air is sucked from the light source box through one or two holes in the air pump and pushed from the air pump into the air pipe of the endoscope through a plastic tube. Because the air pump does not have a dedicated HEPA filter, transmission of microorganisms cannot be excluded. Conclusions Changes are necessary to prevent airborne transmission. Exclusive use of an external CO2 pump and wrapping the endoscope platform with a plastic film will limit scatter of microorganisms. In the era of pandemic virus with airborne transmission, improvements in gastrointestinal ventilation systems are necessary to avoid contamination of patients and health care workers.

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