Optimal micro heat pipe configuration on high performance heat spreaders by seema s. The operating principles, heat transfer characteristics, and fabrication process of memsbased micro. What is a heat pipe heat pipes basics and technology. The capillary condensation efficiency and the liquid transport play two important roles in the cooling performance. Heat pipes employ phase change to transfer thermal energy from one point to another by the vaporization and condensation of a working fluid or coolant.
An essential guide for practicing engineers and an ideal text for postgraduate students, the book takes a highly practical approach to the design and selection of heat pipes. It is both a useful sourcebook and an accessible introduction for those approaching the topic for the first time. Design considerations when using heat pipes electronics cooling. Design and fabrication of a metallic microheat pipe based on high. In this project the main purpose is to select the working. Heat pipe product reliability guide water heat pipe parameters and limitations.
In this video well be taking a look at how micro plate heat exchangers work as well as their applications within chillers, heat pumps and heat recovery. Accordingly, furukawa electric has been marketing heat sinks that incorporate micro heat pipes since 1995. Furthermore, the heat pipes will operate in a horizontal position. Loop heat pipe with coherent porous wick since the porous material used for current heat pipes is usually stochastic structure, it is hard to apply analytical or numerical methods for design optimization. Microelectromechanical systems memsbased microheat pipes, as a novel heat pipe technology, is considered as one of the most promising options for thermal control applications in microelectronic circuits packaging, concentrated solar cells, infrared detectors, microfuel cells, etc. Heat pipe design and technology modern applications for. The concept considered here uses low enriched urania rods and potassium liquid metalcooled hps to remove heat from the core.
The fabrication and purpose of very small wickless heat pipes are discussed. Test procedures for heat pipes destined for use in orbiting satellites have their own special requirements brought about by the need to predict performance in zero gravity by testing in earth gravity. This book provides a practical study of modern heat pipe engineering, discussing how it can be optimized for use on a wider scale. The innovative design of the micro heat pipe uses sharpcornered square, triangular, or other polygonal channels that can serve as capillary arteries, see fig. Heat pipes 6 th edition is an essential guide for practicing engineers and an ideal text for postgraduate students. The first major contribution was the development and advances of new heat pipes, such as loop heat pipes lhps, micro and miniature heat pipes, and pulsating heat pipes phps. Microelectromechanical systems mems based microheat pipes, as a novel heat pipe technology, is considered as one of the most promising options for thermal control applications in microelectronic circuits packaging, concentrated solar cells, infrared detectors, microfuel cells, etc. Variable conductance heat pipes vchp loop heat pipes. This book is designed to help students, operations engineers, andmechanical. Beginning with a definition of the problem, including the temperature.
Having in view the geometrical characteristics, the peano curve fractal may be used for heat pipe device. Heat pipes heat transport limit for proper heat pipe operation, the total pressure drop must not exceed its capillary pressure head. A theoretical analysis of their performance characteristics shows that they have nearly the heat transport capability expected by scaling down from conventional heat pipes. The time of beginning of heat pipe science was near 40 years ago with first heat pipe definition and prediction of most simple cases. However, in an actual application when a heat pipe is soldered or epoxied to the base of a heat sink, the effective thermal conductivity of the heat pipe may be. Heat transfer limitation of a micro heat pipe journal of electronic. Amir faghri written to cover simple, intermediate, and advanced approaches to the theoretical and experimental analysis of heat pipes, this second edition emphasizes the physics and mathematics of heat pipes as well as the related technological and experimental issues. Micro heat pipe phenomena is often available in nature. A miniature heat pipe is defined as a heat pipe with a hydraulic diameter in the range of 0.
A micro heat pipe is defined as a heat pipe in which the mean curvature of the liquidvapor interface is comparable in magnitude to the reciprocal of the hydraulic radius of the total flow channel. This book introduces operational and design principles for heat pipes. Long established as the standard work on heat pipes suitable for use as a professional reference and graduate text. We explore the potential for fuel cycle performance improvement of a generic heat pipe cooled reactor concept from the literature. Its also compatible with numerous refrigerants, making it easy to integrate into. When you design a heat pipe there are three main selection to do, working. Opentype mini micro heat pipes are suggested in, as a system of thermal control of biological objects and drying technology. Micro and miniature heat pipes have received considerable. Ats engineering ebook advanced thermal solutions, inc. The total heat load a heat pipe can carry is a function of total length, evaporator and condenser length, diameter, and orientation with respect to gravity. Ideal when heat needs to be moved more than 3050mm remote fin stacks heat exchangers are a perfect example as with any heat pipe heat sink design, size the heat pipe with an additional 25% thermal headroom if youre interested in spreading heat to reduce hot spot andor attach to a local heat exchanger. Micro heat pipes for cooling electronic devices were proposed in 83. Pdf micro flat heat pipes for microelectronics cooling.
Your complete resource on heat pipe operation, behavior,performance characteristics, and limitations this book is designed to help students, operations engineers, andmechanical and electrical engineers in the electronic packagingindustry grasp the principles of operation for a wide range of heatpipes. Both heat pipes and solid core creates a monolithic core which is a key to the reliability and safety of a long life decentralized energy system. The theory of microheat pipe was introduced by cotter in 1984. It is a common practice to include a slight excess of working fluid over and above that required to saturate 147.
Heat pipes are used in a wide range of applications, including electronics cooling, diecasting and injection moulding, heat recovery and energy conservation, deicing and manufacturing process temperature control, and in domestic appliances. Review and advances in heat pipe science and technology. There are several limits that govern heat pipe theory, however in terrestrial applications the capillary limit is the most limiting factor. Highperformance micro heat pipe by koji yamamoto, kenji nakamizo, hideaki kameoka 2 and kenichi namba 3 with greater electronic equipment speeds and higher performance, more heat is generated posing acute problems of heat dissipation. Micro heat pipe device utilizing extended nanofluidics rsc. The structural and operational parameters have nonlinear relationship which effect on thermal performance of mhp. Heat pipe, journal of thermophysics and heat transfer, vol. Nov 24, 20 wire sandwiched micro heat pipes part 1. Heat pipes are remarkably versatile devices, capable of being manufactured at the very small scale such as for cooling electronic devices and on a much larger scale such as for. For example, there is an analogy between micro heat pipe operation and functioning of a sweat gland. Besides, some innovative ideas and novel micro flat heat pipe designs for particular applications are also documented along with comparisons and discussion.
Mar 15, 2005 a novel flat heat pipe has been developed to assist in meeting the high thermal design requirements in high power microelectronics, power converting systems, laptop computers and spacecraft thermal control systems. Nov 25, 2016 heat pipe science and technology, second edition by dr. Micro and miniature heat pipes electronic component coolers. Micro plate heat exchanger mphe how they work, working. Packed with examples and design information, it takes youthrough the. Heat pipe science and technology, second edition by dr.
Overall, heat pipes theory, design and applications is an excellent book that covers the subject in great depth for the benefit of heat pipe designers and users. Successful analysis and modeling of micro heat pipes requires a complete understanding of the vaporliquid interface. However, in an actual application when a heat pipe is soldered or epoxied to the base of a heat sink, the effective thermal conductivity of the heat pipe may be drastically reduced due to the extra thermal resistances added by the bonding. The heat pipe temperature reaches the water temperature in about 25 seconds, while the copper rod reaches just 30c after 200 seconds. The micro heat pipe cooled reactor is a highly evolved design and of great potential in space missions and decentralized electricity markets. Heat pipe engineering ebook advanced thermal solutions. Heat pipes rely on a temperature difference between the ends of the pipe, and cannot lower temperatures at either end below the ambient temperature hence they tend to equalize the temperature within the pipe. This allows the use of high volume, lower cost heat pipes in a heat sink design. Here, we present the fuel cycle and neutronics analysis of a design expected to be similar to the westinghouse evinci heat pipe hp reactor. Aug 25, 2016 the following example, summarized in table 2, is presented to illustrate how heat pipes might be used to solve a thermal challenge for 70 w heat source with dimensions 20 mm x 20mm and a single 90 degree heat pipe bend required to transport heat from evaporator to condenser. Nam nguyen who developed the heat pipe fluid properties. Packed with examples and design information, it takes you through the background and. Heat pipe design handbook, volume 1 internet archive. This book takes a highly practical approach to the design and selection of heat pipes.
Investigation of a novel flat heat pipe journal of heat. A rule of thumb for the effective thermal conductivity of a heat pipe is 4000 wmk. The background physics of fluids, their behavior in heat pipes, and associated interfacial phenomena heat pipe design methodologies and manufacturing considerations applications for cooling both electrical and mechanical systems the full range of heat pipe classifications, including rotating and revolving, micro, cryogenic, and variable conductance heat pipes, as well as thermal diodes and. Fractals used in a heat pipe cooling device in this chapter are presented some mathematical aspects which define the form, the construction and constrain the design of the fractal networks used in heat pipe cooling devices. The ultimate goal was to reduce the spreading resistance and eliminate localized hot spots. Typically, micro heat pipes have convex but cusped cross sections e. A good description of the history of the heat pipe technology can be found in an early article published by yale eastman currently a director of act in scientific american in may 1968. Optimal micro heat pipe configuration on high performance. Analysis of fuel cycle performance and environmental impacts. These are closely linked to each other to achieve best conditions. The interfacial thermodynamics of micro heat pipes journal. The background physics of fluids, their behavior in heat pipes, and associated interfacial phenomena heat pipe design methodologies and manufacturing considerations applications for cooling both electrical and mechanical systems the full range of heat pipe classifications, including rotating and revolving, micro, cryogenic, and variable. Mar 12, 2018 the new zdesign micro plate heat exchanger delivers 40% higher heat transfer and decreased energy consumption.
The full range of heat pipe classifications, including rotating and revolving, micro, cryogenic, and variable conductance heat pipes, as well as thermal diodes and switches this book provides all the information and guidance you need to increase your understanding of these innovative devices and to begin to apply them to the thermal control of. The focus is to quantify the impact of neutron leakage and parasitic absorption, due to the monolith. A novel flat heat pipe has been developed to assist in meeting the high thermal design requirements in high power microelectronics, power converting systems, laptop computers and spacecraft thermal control systems. Heat pipes and its applications lunds tekniska hogskola. Singh the purpose of this research was to determine the optimal micro heat pipe mhp configuration on high performance heat spreaders. Project description by means of knowledge about the theory of heat pipes, one is now able to carry out a basic calculation of a heat pipe. Describes such heat pipes as revolving, micro, cryogenic, variable. A thermodynamic model of the vaporliquid interface in micro heat pipes has been formulated that includes axial pressure and temperature differences, changes in local interfacial curvature, marangoni effects, and the disjoining pressure. Your complete resource on heat pipe operation, behavior, performance characteristics, and limitations this book is designed to help students, operations engineers, and mechanical and electrical engineers in the electronic packaging industry grasp the principles of. Packed with examples and design information, it takes youthrough the background and. Solid0core heatpipe nuclear batterly type reactor technical. Your complete resource on heat pipe operation, behavior, performance characteristics, and limitations this book is designed to help students, operations engineers, and mechanical and electrical engineers in the electronic packaging industry grasp the principles of operation for a wide range of heat pipes. A loop heat pipe with coherent pores integrated to the heat source is considered as a calculation model in this paperfig. Then, other emerging memsbased microheat pipes, such as microcapillary pumped loop.