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. Media in category pop pop boat the following 21 files are in this category, out of 21 total. It is a member of wickless heat pipes the oscillation of working fluid and phase change phenomina in capillary tube is basic principle. The basic structure of a typical pulsating heat pipe consists of meandering capillary tubes having no internal wick structure, as shown in figure 1a. Oscillating heat pipes ohp, also referred to as pulsating heat pipes php, are a relatively new development in the field of heat pipe technology.
In these conditions, heat transfer mechanism is affected by the pulsating flow parameters. Hybrid pulsating heat pipe for space applications with non uniform. Thermal performance of a pulsating heat pipe with various. Therefore, a new heat pipe called the pulsating or oscillating heat pipe php was introduced by akachi in 1990 4. Ats engineering ebook advanced thermal solutions, inc. Beginning with a definition of the problem, including the temperature. A flat plate php was integrated into an aluminum flat plate heat sink with a simulated electronic load. Pulsating heat pipe is an effective method of heat transfer through passive two phase mechanism. Pdf on jan 1, 2019, viacheslav cheverda and others published water pulsating heat pipe find, read and cite all the research you need on. Journals pdf frontiers in heat pipes fhp effect of. High performance ultra thin heat pipe cooling module for. Originally developed and patented by hisateru akachi in 1990, ohps consist of a long meandering tube which is heated and cooled at various points along its length.
Indian institute of technology kanpur, kanpur up 208016 india. In this experiment the performance of pulsating heat pipe using ethanol and distilled water is experimented. A heat pipe system is integrated in the electronics board between case and wedgelock and a twophase pumped system is integrated to replace a liquid cooling system. Individual images could be stored on a pcmcia card in a bit map format and could be. Experimental research on heat transfer of pulsating heat pipe. At the hot interface of a heat pipe a liquid in contact with a thermally conductive solid surface turns into a vapor by absorbing heat from that surface. An experimental investigation on pulsating heat pipes with duallayer and single layer configurations was conducted in order to determine the effect of the heat transfer and overall system performance given a constrained dimensional heat source with a duallayer arrangement. A php is a simple in structure with a small diameter coil partially filled with certain working fluid in it and extended from the heat source to sink. Thermal performance of closed loop pulsating heat pipe. Heat pipe science and technology, an international journal is encompassed on publishing i fundamental studies of heat and mass transfer in heat pipes and twophase thermosyphons, ii new streams of technology development, iii industrial innovation in electronic thermal control, air conditioning, heating and cooling, aerospace thermal control. The combined effect of sudden pipe expansion and pulsation frequency on the heat transfer was carried out for both locations of pulsating system upstream and downstream when the upstream. Php uses the technique of transporting the working fluid by means of.
An introduction to pulsating heat pipes electronics cooling. A pulsating heat pipe php 1 is a passive and extremely efficient way of exchanging heat between a hot source and a cold one. Modeling of pulsating heat pipes sandia national laboratories. Characteristics of an openloop pulsating heat pipe and. The closed loop pulsating heat pipe of inner diameter 2mm is filled with one of the fluid with a filling ratio of 50% and the variation of temperature is observed for every 2 minutes interval of time at 100 watts, 120 watts 1nd 140 watts. Under different fill ratio, heat transfer rate and many other influence factors, the flow patterns were observed in the startup, transition and stable stage. Abstract pulsating heat pipes phps are the new addition to.
Heat transfer in a pulsating heat pipe with open end. Publishers pdf, also known as version of record includes final page, issue and volume numbers. Member of the committee on international heat pipe conferences 1973, acted as committee chairman from 1990 till 2004, and since. The simplicity of the gravity return heat pipe makes this the preferred solution for a wide range of heat pipe applications. Pulsating heat pipes phps are used as high efficiency heat exchangers, and the selection of working fluids in phps has a great impact on the heat transfer performance. The dual layer configuration is an assembly of two pulsating heat pipes of equal measurement.
The oscillating or pulsating heat pipe oph or php is a very promising heat transfer device. Introduction figure 1 shows a schematic of a pulsating heat pipe php were the change in volume of the vapor bubbles. They differ by their geometry and a mechanism of fluid transport inside the heat pipe. Pdf the oscillating or pulsating heat pipe oph or php is a very promising heat transfer device. Characteristics of an openloop pulsating heat pipe and flow visualization using a transparent tube koji fumoto a, masahiro kawaji b and tsuyoshi kawanami c a hirosaki university, 3 bunkyocho, hirosaki, 0368561, japan b city college of new york, new york, ny 10032, usa c kobe university, 11 rokkodaicho, nadaku, kobe, 6578501, japan. Heat transfer in the evaporator and condenser sections of a pulsating heat pipe php with open end is modeled by analyzing thin film evaporation and condensation. In this context, pulsating heat pipe php cooling is the new.
Twophase passive devices are proven solutions for modern microelectronics thermal management. Pdf cfd simulation of a pulsating heat pipe using ansys. How to make a heat pipe or solar heat collector duration. Pulsating heat pipes, apparently simple and very promising cooling devices, are very intriguing for theoretical and experimental investigations alike. A unique experimental apparatus able to reproduce a pulsating flow representative of the engine exhaust has been designed. An introduction to pulsating heat pipes may 1, 2003 sameer khandekar heat pipes design, liquid cooling, number 2, php, pulsating heat pipe, volume 9 modern electronics thermal management faces considerable challenges in the wake of component miniaturization, which has led to higher demands on net heat flux dissipation. This new edition has been revised to include new information on the underlying theory of heat pipes and heat transfer, and features fully updated applications, new data sections, and. Heat pipes are referred to as the superconductors of heatdue to their fast transfer capability with. A heat pipe is a structure with very high thermal conductivity that enables the transportation of heat whilst maintaining almost uniform temperature along. In addition to its excellent heat transfer performance, it has a simple structure. A multiturn compact closed loop php is made of aluminum and partially filled with fc72 50% vol. Introduction akachi proposed and patented pulsating or loop type heat pipein 1990s 1. Operational limit of closed loop pulsating heat pipes.
Pulsating heat pipe, fill ratio, orientation, working fluids introduction. Benefits and drawbacks of using twophase cooling technologies in military platforms. The results showed that the thermal performance of the pulsating heat pipe was different according to working conditions. The pulsating called also oscillating heat pipe php is a simple capillary tube bent in meander and filled with a twophase fluid. Two configurations of pulsating heat pipe i open loop ii closed loop cooling philosophy of pulsating heat pipes to achieve the objective of this paper, it is worthwhile to begin with an overall perspective on the principal ideas behind various heat transfer technologies. The effects of the battery cell stack arrangement, heating ratio, and inclination angle were analyzed at various heat inputs. Pulsating heat pipe php is a heat exchanger device which absorbs heat from. A rule of thumb for the effective thermal conductivity of a heat pipe is 4000 wmk.
A heat pipe is a heattransfer device that combines the principles of both thermal conductivity and phase transition to effectively transfer heat between two solid interfaces. Pdf heat transfer in a pulsating heat pipe with open end. Its the two phase heat transfer device suitable for low power applications such as electronic cooling. Effect of filling ratio on thermal performance of closed. To make liquid and vapour plugs to exist diameter of tube must be small. Each of these processes has proven feasibility and used together can readily produce mephps.
Pulsating heat pipe pulsating or oscillating heat pipe, invented in early 1990s present promising alternatives for the removal of high localized heat fluxes to provide a necessary level of temperature uniformity across the components that need to be cooled. Table 1 documents parameter combinations that correspond to a few cases. Groll c a college of environmental science and engineering, donghua university, shanghai 200051, pr china b mechanical engineering department, indian institute of technology kanpur, kanpur 208016, india c institute of nuclear technology and energy systems, university of stuttgart. This study investigates the thermal resistance characteristics of the php charged with acetonebased binary mixtures, where deionized water, methanol and ethanol were added to and mixed with. The pulsating heat pipe affords a highly effective heat transfer component that has been extensively researched at room temperature, but is.
A heat pipe heat exchanger is a simple device which ismade use of to transfer heat from one location to another,using an evaporationcondensation cycle. The objective of the present work is to experimentally investigate heat transfers for pulsatile turbulent flows in a pipe. Our proprietary diffusion bonding technology is then applied to assemble the mephps. Thermomhydrodynamics of closed loop pulsating heat pipes iitk. Heat pipes have been widely applied in the electronic cooling field because they are capable of passively transferring a large amount of heat with a small temperature difference. An experimental investigation of micro pulsating heat pipes. Peregrine embeds pulsating heat pipes within the plane of flat sheetsplates by using printed circuit board technology to micromachine the channels.
This makes it a very inexpensive and easytointegrate heat spreader which can be bene. A new teslatype valve is successfully designed for promoting circulation in a pulsating heat pipe php. The pulsating heat pipe php shows potential to meet this need, due to its high heat flux capacity, simplicity, and low cost. Closed loop pulsating heat pipe php is a twophase passive heat transfer device proposed and patented by akachi 1990. In the present research work, experimental studies were performed on pulsating heat pipe made from copper tube having internal and external diameter of 2 mm and 3 mm respectively. The inside diameter of the tube is sufficiently small critical bo. A hybrid loop thermosyphonpulsating heat pipe named space pulsating heat pipe sphp is tested both on ground and in hypermicrogravity conditions. A pulsating heat pipe php is typically a multiturn capillary tube containing a working fluid with a. The simulation of a 2d single loop pulsating heat pipe using. Paper open access design and operation of a cryogenic. Design and operation of a teslatype valve for pulsating. On the design fundamentals of pulsating heat pipes.
Experimental analysis of a flat plate pulsating heat pipe. Heat pipes have, however, been manufactured which rely on the capillary action of a wick to provide bidirectional operation. Experimental research was conducted to understand heat transfer characteristic of pulsating heat pipe in this paper, and the php is made of high quality glass capillary tube. Microsoft word gian brochure introduction to heat pipe science and technology.
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. This report presents a numerical model of a pulsating heat pipe, a device employing a two phase. They are attractive heat transfer elements, which due to their simple design, cost effectiveness, and excellent thermal performance may find wide applications. Files are available under licenses specified on their description page. Culham microelectronics heat transfer laboratory department of mechanical engineering university of waterloo waterloo, ontario, canada, n2l 3g1 phone.
A closed loop pulsating heat pipe php consists of a capillarysized tube or channel arranged in. The experimental results demonstrate the heat transfer characteristics, lower thermal resistance and higher heat transfer coefficient of php are found to be better at a fill ratio of 60% for various heat input. Heat transfer performance of a pulsating heat pipe charged. Heat pipes, 6th edition, takes a highly practical approach to the design and selection of heat pipes, making it an essential guide for practicing engineers and an ideal text for postgraduate students. Operational limit of closed loop pulsating heat pipes honghai yang a, s. If you have a disability and are having trouble accessing information on this website or need materials in an alternate format, contact web. Design and operation of a teslatype valve for pulsating heat pipes citation for published version apa. High performance ultra thin heat pipe cooling module for mobile hand held electronic devices. Gian brochure introduction to heat pipe science and. Computational model of miniature pulsating heat pipes sandia.
Even the name is heat pipe,but working is very much different than the conventional heat pipes. Stl files into flow3d and superimposed upon the domain of. Large diameter pulsating heat pipe for future experiments. Innovative cooling by pulsating heat pipe for hts superconducting coil objective and scientific interest the objective of the project is the realization and testing of an oscillating heat pipecooled hts superconducting coil with metalasinsulation winding. The heat transfer solutions are applied to the thermal model of the pulsating heat. In recent years, heat pipes have been widely used in various hand held mobile electronic. Performance analysis of pulsating heat pipes using various.