Thermal Management of a 15 kV/100 kVA Intelligent Universal Transformer

2011 ◽  
Vol 3 (1) ◽  
Author(s):  
Ronald Warzoha ◽  
Amy S. Fleischer
Keyword(s):  
Heat Pipe ◽  
Power Electronics ◽  
Thermal Management ◽  
Operating Temperature ◽  
Heat Pipes ◽  
Sensitivity Study ◽  
Design Sensitivity ◽  
Thermal Dissipation ◽  
System Failure ◽  
Significant Challenge

The thermal management of power electronics presents a significant challenge to thermal engineers due to high power loads coupled with small footprints. Inadequate thermal dissipation of these loads can lead to excessively high equipment temperatures and subsequent system failure. In this study, a unique power electronics-based transformer, called the intelligent universal transformer (IUT), is thermally analyzed using the computational fluid dynamics software ICEPAK. The objective of this work is to examine the use of a finned heat pipe array for the power electronics in the IUT. A design sensitivity study was performed to determine the effect of the number of fins attached to the heat pipe array, the number of heat pipes in the heat pipe array, and the fin material on the steady-state operating temperature of the power electronics. It was determined that a set of 33 copper fins attached to an array of 36 heat pipes on each side of the containment unit is sufficient for continuous operation of the power electronics. This analysis and thermal management solution will be applicable not only to this situation but also to other high density power electronics applications.

A Simplified Conduction Based Modeling Scheme for Design Sensitivity Study of Thermal Solution Utilizing Heat Pipe and Vapor Chamber Technology

2003 ◽  
Vol 125 (3) ◽  
pp. 378-385 ◽  
Author(s):  
Ravi S. Prasher
Keyword(s):  
Heat Pipe ◽  
Temperature Drop ◽  
Heat Pipes ◽  
Sensitivity Study ◽  
Design Sensitivity ◽  
Thermal Design ◽  
Vapor Chamber ◽  
Modeling Tools ◽  
Heating Source ◽  
Thermal Solution

This paper introduces a simplified modeling scheme for the prediction of heat transport capability of heat pipes and vapor chambers. The modeling scheme introduced in this paper enables thermal designers to model heat pipes and vapor chambers in commercially available conduction modeling tools such as Ansys™ and IcePak™. This modeling scheme allows thermal designers to perform design sensitivity studies in terms of power dissipation of heat pipes and vapor chambers for different scenarios such as configurations, heat sink resistance for a given temperature drop between the heating source and the ambient. This paper also discusses how thermal designers can specify requirements to heat pipe/vapor chamber suppliers for their thermal design, without delving into the complete thermo-fluidic modeling of this technology.

A Simplified Modeling Scheme for Design Sensitivity Study of Thermal Solution Utilizing Heat Pipe and Vapor Chamber Technology

2001 ◽  
Author(s):  
Ravi S. Prasher ◽  
James Shipley ◽  
Amit Devpura
Keyword(s):  
Heat Pipe ◽  
Temperature Drop ◽  
Heat Pipes ◽  
Sensitivity Study ◽  
Design Sensitivity ◽  
Thermal Design ◽  
Vapor Chamber ◽  
Modeling Tools ◽  
Heating Source ◽  
Simplified Modeling

Abstract This paper introduces a simplified modeling scheme for the prediction of heat transport capability of heat pipes and vapor chambers. The modeling scheme introduced in this paper enables thermal designers to model heat pipes and vapor chambers in commercially available conduction modeling tools such as Ansys™ and IcePak™. This modeling scheme allows thermal designers to perform design sensitivity studies in terms of power dissipation of heat pipes and vapor chambers for different scenarios such as configurations, heat sink resistance for a given temperature drop between the heating source and the ambient. This paper also discusses how thermal designers can specify requirements to heat pipe/vapor chamber suppliers for their thermal design, without delving into the complete thermofluidic modeling of this technology.

scholarly journals Thermal performance of Pulsating Heat Pipe on Electric Motor as Cooling Application

2018 ◽  
Vol 67 ◽  
pp. 03035 ◽  
Author(s):  
Nurhalimah Aprianingsih ◽  
Adi Winarta ◽  
Bambang Ariantara ◽  
Nandy Putra
Keyword(s):  
Heat Pipe ◽  
Thermal Management ◽  
Thermal Performance ◽  
Electric Motor ◽  
Management System ◽  
Operating Temperature ◽  
Heat Pipes ◽  
Working Fluid ◽  
Pulsating Heat Pipe ◽  
Thermal Management System

Heat generated in an electric motor can increase the operating temperature. The excessive operating temperature will reduce the electric motor performance and shorten the service life. An appropriate thermal management system is required to reduce the electric motor operating temperature. The objective of this study is to determine the thermal performance of pulsating heat pipes which applied to the electric motor thermal management system. A prototype of electric motor thermal management system was made from an induction motor with a cartridge heater instead of a heat-generating rotor and stator. Six pieces of pulsating heat pipe were mounted using hexagonal heat pipe holder which placed inside the electric motor housing. The pulsating heat pipes are made of a copper capillary tube using acetone as working fluid with a filling ratio of 0.5. The electric power input was varied from 30 W to 150 W. The use of pulsating heat pipes can reduce the electric motor surface temperature by 55.3°C with the minimum thermal resistance of 0.151°C/W.

A Numerical Analysis of Gas Turbine Disks Incorporating Rotating Heat Pipes

2000 ◽  
Author(s):  
Y. Cao ◽  
J. Ling ◽  
R. Rivir ◽  
C. MacArthur
Keyword(s):  
Heat Pipe ◽  
Gas Turbine ◽  
Heat Pipes ◽  
High Heat ◽  
Thermal Dissipation ◽  
High Heat Flux ◽  
Heating And Cooling ◽  
Turbine Disks ◽  
Higher Temperature ◽  
Lower Temperature

Abstract Radially rotating heat pipes have been proposed for cooling gas turbine disks working at high temperatures. A disk incorporating the heat pipe would have an enhanced thermal dissipation capacity and a much lower temperature at the disk rim and dovetail surface. In this paper, extensive numerical simulations have been made for heat-pipe-cooled disks. Thermal performances are compared for the disks with and without incorporating the heat pipe at different heating and cooling conditions. The numerical results presented in this paper indicate that radially rotating heat pipes can significantly reduce the maximum and average temperatures at the disk rim and dovetail surface under a high heat flux working condition. In general, the maximum and average temperatures at the disk rim and dovetail surface could be reduced by above 250 and 150 degrees, respectively, compared to those of the disk without the heat pipe. As a result, a disk incorporating radially rotating heat pipes could alleviate temperature-related problems and allow a gas turbine to work at a much higher temperature.

Thermal Design and Testing of a Passive Helmet Heat Exchanger With Additively Manufactured Components

2018 ◽  
Author(s):  
Kailyn Cage ◽  
Monifa Vaughn-Cooke ◽  
Mark Fuge ◽  
Briana Lucero ◽  
Dusan Spernjak ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Heat Pipe ◽  
Thermal Management ◽  
Heat Pipes ◽  
Thermal Design ◽  
Analytical Models ◽  
Small Scale ◽  
Dimensional System ◽  
Concept Design ◽  
Environmental Chamber

Additive manufacturing (AM) processes allow for complex geometries to be developed in a cost- and time-efficient manner in small-scale productions. The unique functionality of AM offers an ideal collaboration between specific applications of human variability and thermal management. This research investigates the intersection of AM, human variability and thermal management in the development of a military helmet heat exchanger. A primary aim of this research was to establish the effectiveness of AM components in thermal applications based on material composition. Using additively manufactured heat pipe holders, the thermal properties of a passive evaporative cooler are tested for performance capability with various heat pipes over two environmental conditions. This study conducted a proof-of-concept design for a passive helmet heat exchanger, incorporating AM components as both the heat pipe holders and the cushioning material targeting internal head temperatures of ≤ 35°C. Copper heat pipes from 3 manufactures with three lengths were analytically simulated and experimentally tested for their effectiveness in the helmet design. A total of 12 heat pipes were tested with 2 heat pipes per holder in a lateral configuration inside a thermal environmental chamber. Two 25-hour tests in an environmental chamber were conducted evaluating temperature (25°C, 45°C) and relative humidity (25%, 50%) for the six types of heat pipes and compared against the analytical models of the helmet heat exchangers. Many of the heat pipes tested were good conduits for moving the heat from the head to the evaporative wicking material. All heat pipes had Coefficients of Performance under 3.5 when tested with the lateral system. Comparisons of the analytical and experimental models show the need for the design to incorporate a re-wetting reservoir. This work on a 2-dimensional system establishes the basis for design improvements and integration of the heat pipes and additively manufactured parts with a 3-dimensional helmet.

Production Stainless Gravitational Heat Pipes Filled with Distilled Water

2016 ◽  
Vol 832 ◽  
pp. 184-191 ◽  
Author(s):  
Marián Jobb ◽  
Ľuboš Kosa ◽  
Michal Holubčík ◽  
Radovan Nosek
Keyword(s):  
Heat Pipe ◽  
Operating Temperature ◽  
Heat Pipes ◽  
Distilled Water ◽  
Aisi 304 ◽  
Working Temperature ◽  
Essential Function ◽  
Aisi 316 ◽  
Process Measurements ◽  
Pipe Manufacturing

This article deals with the performance of heat pipes, depending on the operating temperature and positions (operation angle). There is described the essential function of the heat pipe manufacturing process. Measurements were carried at an operating temperature of 40 °C to 90 °C. Stainless heat pipes were made of three kinds of materials AISI 304, AISI 310, AISI 316 and filled with a distilled water, up to 20% of the heat pipe inner volume. For each material was selected heat pipe with the best results. The heat pipes were measured at various angles of vertical inclination (0 ° - 90 °), at the working temperature 90 ° C. The performance was measured on the experimental device. Presented results show the progress of individual measurements and the effect of operating parameters on the performance of heat pipes.

Thermal Management of a Heat-Pipe Drill: A FEM Analysis

2003 ◽  
Author(s):  
Tien-Chien Jen ◽  
Rajendra Jadhav
Keyword(s):  
Finite Element ◽  
Heat Pipe ◽  
Thermal Management ◽  
Heat Pipes ◽  
High Heat ◽  
Heat Fluxes ◽  
High Heat Flux ◽  
Drilling Process ◽  
Generation Process ◽  
Finite Element Software

Thermal management using heat pipes is gaining significant attention in past decades. This is because of the fact that it can be used as an effective heat sink in very intricate and space constrained applications such as in electronics cooling or turbine blade cooling where high heat fluxes are involved. Extensive research has been done in exploring various possible applications for the use of heat pipes as well as understanding and modeling the behavior of heat pipe under those applications. One of the possible applications of heat pipe technology is in machining operations, which involves a very high heat flux being generated during the chip generation process. Present study focuses on the thermal management of using a heat pipe in a drill for a drilling process. To check the feasibility and effectiveness of the heat pipe drill, structural and thermal analyses are performed using Finite Element Analysis. Finite Element Software ANSYS was used for this purpose. It is important for any conceptual design to be made practical and hence a parametric study was carried out to determine the optimum geometry size for the heat pipe for a specific standard drill.

Operational Limitations of Heat Pipes With Silver-Water Nanofluids

2013 ◽  
Vol 135 (11) ◽  
Author(s):  
Lazarus Godson Asirvatham ◽  
Rajesh Nimmagadda ◽  
Somchai Wongwises
Keyword(s):  
Silver Nanoparticles ◽  
Heat Pipe ◽  
Heat Load ◽  
Operating Temperature ◽  
Particle Diameter ◽  
Heat Pipes ◽  
Working Fluid ◽  
Limit Value ◽  
Capillary Limit ◽  
Nanoparticles Concentration

The paper presents the enhancement in the operational limits (boiling, entrainment, sonic, viscous and capillary limits) of heat pipes using silver nanoparticles dispersed in de-ionized (DI) water. The tested nanoparticles concentration ranged from 0.003 vol. % to 0.009 vol. % with particle diameter of <100 nm. The nanofluid as working fluid enhances the effective thermal conductivity of heat pipe by 40%, 58%, and 70%, respectively, for volume concentrations of 0.003%, 0.006%, and 0.009%. For an input heat load of 60 W, the adiabatic vapor temperatures of nanofluid based heat pipes are reduced by 9 °C, 18 °C, and 20 °C, when compared with DI water. This reduction in the operating temperature enhances the thermophysical properties of working fluid and gives a change in the various operational limits of heat pipes. The use of silver nanoparticles with 0.009 vol. % concentration increases the capillary limit value of heat pipe by 54% when compared with DI water. This in turn improves the performance and operating range of the heat pipe.

scholarly journals Staying Cool

1999 ◽  
Vol 121 (07) ◽  
pp. 64-65
Author(s):  
Calvin C. Silverstein
Keyword(s):  
Heat Pipe ◽  
Thermal Management ◽  
Liquid Flow ◽  
High Performance ◽  
Heat Pipes ◽  
Flow Channel ◽  
Aircraft Engines ◽  
Chemical Milling ◽  
Combination Of Methods ◽  
Half Thickness

This article reviews heat pipes that address thermal management problems inside high-performance aircraft engines. Higher performance engines demand that compressors develop higher pressure ratios which, in turn, result in higher temperatures at the entrance to the combustor. CCS Associates of Bethel Park, PA, proposes tackling the problem by using pipes to distribute heat more effectively throughout the combustor. The heat pipe liner must handle both acceleration and vibration. The heat pipe arrays, including half-thickness webs, can be fabricated into gas-side and air-side halves by extrusion, forging, stamping, chemical milling, or some combination of methods. The liquid flow channel would be formed as an integral part of the gas-side valves.

scholarly journals Improvement of Heat Pipe Solar Collector Thermal Efficiency Using Al2O3/Water and TiO2/Water Nanofluids

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Sinan Ünvar ◽  
Tayfun Menlik ◽  
Adnan Sözen ◽  
Hafız Muhammad Ali
Keyword(s):  
Heat Pipe ◽  
Heat Exchangers ◽  
Base Fluid ◽  
Operating Temperature ◽  
Pure Water ◽  
Heat Pipes ◽  
Working Fluid ◽  
Solar Collectors ◽  
Instantaneous Power ◽  
Operating Temperature Range

Heat pipe solar collectors (HPSCs) are heat exchangers that carry heat based on the phase change of the heat pipe working fluid. It is aimed to increase the operating temperature range of solar collectors by changing the phase of the working fluid in the heat pipe at low temperature. For this reason, it has become widespread to use nanofluids obtained by mixing nanosized metal oxides with the base fluid in certain proportions in order to increase both the thermal conductivity of the heat pipe working fluids and to increase the specific heat closures. The main purpose of this study, which was conducted to evaluate the performance of HPSCs, is to increase performance, and an experimental study has been conducted in this direction. For this purpose, an HPSC designed and manufactured was used. Al2O3-water and TiO2-water nanofluids containing 2% nanoparticles were used in order to increase performance in the study. HPSC used in the study consists of 8 heat pipes with a length of 100 cm. The experiments were carried out for pure water and nanofluids, and their efficiency and strength were compared. The highest value of instantaneous efficiency was calculated as 48% when pure water was used as the working fluid, 58% for Al2O3-water nanofluid, and 64% for TiO2-water nanofluid. The instantaneous power obtained using pure water was determined as 135.66 W, 167.96 W for Al2O3-water nanofluid, and 184.03 W for TiO2-water nanofluid. The improvement in efficiency was determined as 20.8% for Al2O3-water nanofluid and 33.3% for TiO2-water nanofluid. Improvement in powers was found to be 23.8% for Al2O3-water nanofluid and 35.6% for TiO2-water nanofluid.

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