Numerical simulation has been conducted for the chaotic flow in a 3d closedloop pulsating heat pipe php. Initially, the oph is evacuated and partially filled with the working fluid. The pulsating heat pipes php, also called oscillating heat pipes, belong to the thermal system category of heat pipes, twophase. To model free boundary flows in general, flow3d utilizes a volume of fluid truvof. An experimental investigation of micro pulsating heat pipes.
A heat pipe device and a corresponding method in which microchannel embedded pulsating heat pipes are incorporated into a substrate. A pulsating heat pipe in action at indian institute of technology kanpur, india. The objective of this study was to experimentally investigate the effects of working fluids and internal diameters on the thermal resistance of rotating closedloop pulsating heat pipes rclphp. Testing was performed showing significant increases in thermal. Design and operation of a teslatype valve for pulsating heat pipes. Abstract the pulsating heat pipe, a serpentine tube of capillary dimension with many turns, has great impact on todays successful thermal management. The inside diameter of the tube is sufficiently small critical bo. Used to cool transistors and high density semiconductors. Nov 06, 2010 a pulsating heat pipe in action at indian institute of technology kanpur, india. Close up of one side of a microchannel pulsating heat pipe mephp assembly. Computational model of miniature pulsating heat pipes sandia. 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. System used by non cryogenists cryogenistfree magnets.
Optical visualization results indicated that there might exist three flow patterns, i. To learn more about the ohp technology and how we innovate custom thermal solutions, click on a topic below. Factor affecting closed loop pulsating heat pipe it can be seen that six major thermomechanical parameters have emerged as the primary design parameters affecting the php system dynamics. Pdf on jan 1, 2019, viacheslav cheverda and others published water pulsating heat pipe find, read and cite all the research you.
A series of experiments were performed on three types of closed loop pulsating heat pipes phps, intending to investigate various kinds of flow patterns, and to develop some improved configurations for the phps. May 01, 2003 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. Performance analysis of pulsating heat pipes using various. Introduction heat pipe is a capillary twophase heat transfer device. Turbulent and laminar pulsating flows in a straight smooth pipe are compared at identical frequencies and reynolds numbers. Tech 2nd year thermal engineering, 2assistant professor, 1,2mechanical department, government college of engineering, amravati m. For various reasons a closed loop pulsating heat pipe clphp is thermally a better option than an open loop device. Ats engineering ebook advanced thermal solutions, inc.
Pdf cfd simulation of a pulsating heat pipe using ansys. Recent advances in electronics design and manufacturing have resulted in significant increases in heat flux density through a miniaturization of components and a. Computational model of miniature pulsating heat pipes. Pdf the oscillating or pulsating heat pipe oph or php is a very promising heat transfer device.
The startup of pulsating heat pipe php leads to the temperature of cpus decrease. The graph also shows that if the heat pipe is operated against the force of gravity, the liquid undergoes a larger pressure drop. 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. The result is less pumping of the wick with reduced heat transfer. Heat exchangers power industries use heat pipe heatexchangers as. The simulation of a 2d single loop pulsating heat pipe using. Internal diameter of the php tube, input heat flux to the device. High speed flow visualization of a closed loop pulsating heat pipe, proceeding of the 11th international heat pipe conference, tokyo, japan, 1999, pp. Moreover, the pulsating heat pipe can be activated in less time and transfer more heat with higher heating power. This report presents a numerical model of a pulsating heat pipe, a device employing a two phase liquid and its vapor working fluid confined in a closed loop channel etchedmilled into a serpentine configuration in a solid metal plate. This paper presents an experimental study on the operational limitation of closed loop pulsating heat pipes clphps, which consist of a total of 40 copper tubes with 1 mm and 2 mm inner diameter, respectively.
Aerospace cool satellite solar array, as well as shuttleleading edge during reentry. Us20080073066a1 pulsating heat pipe with flexible artery. This report presents a numerical model of a pulsating heat pipe, a device employing. Even the name is heat pipe,but working is very much different than the conventional heat pipes. The pulsating heat pipes php, also called oscillating heat pipes, belong to the thermal system category of heat pipes, twophase passive thermal devices used to transfer heat from a hot source to a cold region, with very high equivalent thermal conductivity, higher than any usual metallic material, light, and able to manage high heat fluxes. Experimental analysis of solar water heater using pulsating heat pipe 1d. Nov 11, 2015 sorption heat pipe the sorption heat pipe shp is a novelty and combines the enhanced heat and mass transfer in conventional heat pipes with sorption phenomena of a sorbent bed.
The pulsating heat pipe affords a highly effective heat transfer. Most measurements were made at a mean reynolds number of 4000, but the influence of re was checked for 2900 heat pipe 2 3. Ohp applications and industries ohp technical resources. With the aim of exploring potential applications of pulsating heat pipe php technology for space as well as terrestrial sectors, experimental study of embedded structures in an aluminum substrate subjected to conjugate heat transfer conditions, i. View pulsating heat pipe research papers on academia. They are attractive heat transfer elements, which due to their simple design, cost effectiveness, and excellent thermal performance may find wide applications. Analysis of pulsating heat pipe with capillary wick and varying channel diameter, int.
Pdf in order to enhance the application of a cryocooler that. Efficient heat transferefficient heat transfer boiling and condensationboiling and condensation small temperature difference between the heat source and. Transports heat from a heat source to a heat sink works as an isothermalizer why twophase thermal system. A new structure of rack with inner duct and pulsating heat pipe was suggested. Pulsating heat pipe, fill ratio, orientation, working fluids introduction. May 16, 20 pulsating heat pipe php, or oscillating heat pipe ohp, a novel type of highly efficient heat transfer component, has been widely applied in many fields, such as in spaceborne twophase thermal control systems, in the cooling of electronic devices and in energysaving technology, etc. Thermomhydrodynamics of closed loop pulsating heat pipes. Top and matching bottom microchannel pulsating heat pipe mephp assembly. Investigation on thermal design of a rack with the.
The experiment purpose is the study of optimum operation modes of pulsing heat pipe with enough large sizes and the opportunity of such pipe using as the absorber of solar collector. Pulsating heat pipe, multiphase flow, heat transfer. Pdf thermal resistance of rotating closedloop pulsating. Pdf cfd simulation of a pulsating heat pipe using ansys fluent. Php is a passive miniature form of heat pipe that works on the basic principle of sensible and latent heat transfer with the help of pulsating flow induced by movement of vapor plug and liquid slug after supply of heat in the narrow capillary tube. Its the two phase heat transfer device suitable for low power applications such as electronic cooling. 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. Pulsating heat pipes, apparently simple and very promising cooling devices, are very intriguing for theoretical and experimental investigations alike.
A closed loop pulsating heat pipe php consists of a capillarysized tube or channel arranged in a serpentine. Cryogenic design and colling methods for rotating sc. Sorption heat pipe could be used as a sorption heat transfer element and be cooled and heated as a heat pipe. A pulsating heat pipe php 1 is a passive and extremely efficient way of exchanging heat between a hot source and a cold one. Aug 17, 2011 pulsating heat pipes, apparently simple and very promising cooling devices, are very intriguing for theoretical and experimental investigations alike. Sixty microchannel embedded pulsating heat pipes mephps of. S, india abstractsolar energy is used for solar water heater in domestic and industrial purpose. With pulsating heat pipes php, many problems of heat dissipation may be effectively solved. They are attractive heat transfer elements, which due to their simple design, cost effectiveness, and. Experimental analysis of solar water heater using pulsating. An oscillated heat pipe in research is made of rather long and thin sealed pipe. The pipe is arranged in a serpentine pattern in which freely moving liquid and vapor segments alternate. The rclphp were made of a copper tube with internal diameters of 1.
Effect of fin and insert on the performance characteristics. Focusing on this, an experiment has been done on the open loop pulsating heat pipes olphp to observe their performance characteristics by using two. An overview on the developing trend of pulsating heat pipe. The pulsating heat pipe php is essentially a twophase heat. Investigation on thermal design of a rack with the pulsating. An introduction to pulsating heat pipes electronics cooling. The basic structure of a typical pulsating heat pipe consists of meandering capillary tubes having no internal wick structure, as shown in figure 1a. The temperature field is improved and some hot spots are removed in the rack.
Oscillating heat pipes ohps use thermally driven, twophase fluid flow to rapidly transfer heat between heat sources and heat sinks. A heat pipe is a heat transfer device that combines the principles of both thermal conductivity and phase transition to effectively transfer heat between two solid interfaces. The heat transferred through the pulsating heat pipe increases with the rack heating power, and the temperature of the fins attached on the condenser section becomes higher, so as to the temperature of the evaporator section. These chlorine free radicals act as catalysts in the breakdown of ozone. Peregrine successfully demonstrated the feasibility of embedding pulsating heat pipes within the plane of a sheet. In this study, the verticallyoriented pulsating heat pipe php heat exchangers charged with either water or hfe7000 in a filling ratio of 35% or 50% were fabricated to exchange the thermal energy between two air streams in a parallelflow arrangement. It is an ascending technology to satisfy present requirement of increasing thermal performance. When the diameter of the tube is so small, preferably pulsating heat pipe and its thermal transport behavior. Presently such systems have found niche applications in micropower electronics cooling and the future prospects seem quite promising. In this experiment the performance of pulsating heat pipe using ethanol and distilled water is experimented. Two configurations of pulsating heat pipe i open loop ii closed loop proc. Publishers pdf, also known as version of record includes final page, issue and volume. Php is a capillary tube with no wick structure bent into many turns and partially. Indian institute of technology kanpur, kanpur up 208016 india.
Pdf design of a hydrogen pulsating heat pipe researchgate. The php can be designed as bent pipe or as flat plate. Numerical analysis of performance of closed loop pulsating. The ball is free to move between the valve seat and stopper, but when it is in. The simplified thermal conductivity model of pulsating heat pipe is introduced. Jun 18, 20 heat pipe applications electronics cooling small high performance componentscause high heat fluxes and high heat dissipation demands. We explore and scrutinize two possible configurations of pulsating heat pipe php based heat exchangers for process waste heat exchange as well as high heat flux. Publishers pdf, also known as version of record includes final page, issue and volume numbers. Heat pipe is a capillary twophase heat transfer device. Operational limit of closed loop pulsating heat pipes. Heat flux and constant temperature boundary conditions were applied for evaporator and. Two sibased micro pulsating heat pipes phps charged using hfe7100 were either horizontally or vertically oriented and were tested using several heating powers. Schematic of a typical pulsating heat pipe with design variations. Energies free fulltext experimental investigation on the.
An oscillating heat pipe, also known as a pulsating heat pipe, is only partially filled with liquid working fluid. Peregrine phone 9254616800 fax 9254616804 1051 serpentine lane, suite 100 pleasanton, ca 94566. 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. The amount of heat transfer decrease depends on the particular heat pipe. These tubes are evacuated and partially filled with the working fluid. Pulsating flow in a pipe journal of fluid mechanics. A volume of fluid in a vacuum is introduced into a microchannel which will become slugs of liquid. Paper open access design and operation of a cryogenic.
A pulsating heat pipe 10 includes an elongate capillary tube 11, a working fluid 15 disposed within the elongate tube and an artery mesh disposed in the elongate tube. Pdf embedded pulsating heat pipe radiators semantic scholar. Pulsating heat pipe pulsating heat pipe has many numbers of uturns of tube with capillary diameter. Feb 05, 2018 its the two phase heat transfer device suitable for low power applications such as electronic cooling. Asymmetry and geometry effects on the dynamic behavior of. In the present paper, the characteristics and working principles of the phps are introduced and the. Closed loop pulsating heat pipe is very effective tool for removal of heat from very. Startup heat load, maximum heat load and optimum fill ratio of pulsating heat pipe php of 16 turn, 1 mm id, 2 mm od and 9.