The simulation of a 2d single loop pulsating heat pipe using. A novel cryogenic heat pipe, oscillating heat pipe ohp, which consists of an 4. 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. Performance analysis of pulsating heat pipes using various fluids. Heat pipes are referred to as the superconductors of heatdue to their fast transfer capability with low heat loss.
A pulsating heat pipe or oscillating heat pipe has best potential to handle the above problem. A closed loop pulsating heat pipe php consists of a capillarysized tube or channel arranged in a serpentine configuration see figure 12 and joined end to end e. Pulsating hpp are convenient with the low pressure working fluids like water, alcohol and some hydrocarbons. Our proprietary diffusion bonding technology is then applied to assemble the mephps. Operational limit of closed loop pulsating heat pipes. For example, choice of the wick and case material eliminates many candidate working fluids often including water due to. The oscillating or pulsating heat pipe php is another. Effect of design parameters on performance of closed loop. The pulsating heat pipe affords a highly effective heat transfer component that has been extensively researched at room temperature, but is. Modeling of pulsating heat pipes sandia national laboratories. Jun 18, 20 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.
Flanges can be added on the outer surface for easy integration with instruments or radiators the flange is an integral part of the extrusion. Therefore, this type of heat pipe is essentially a nonequilibrium heat transfer device h. Keywords pulsating heat pipes, closed loop pulsating heat pipes, critical diameter, critical number of turns, filling ratio, working fluids, thermal resistance, start. Pulsating heat pipes, like conventional heat pipes, are closed, twophase systems capable of transporting heat without any additional power input, but they differ from conventional heat. Understanding effect of operating parameters on thermal.
Aug 22, 2019 visualization experiment is a must in realizing functional characteristics of an operational pulsating heat pipe php. Design case study pulsating heat pipe for microgravity application pulsating heat pipe for microgravity application. Thermal behavior of pulsating heat pipe in condition of gravity and. A pulsating heat pipe, sometimes called an oscillating heat pipe, converts heat from the heat generating area into liquidslugs. Pdf cfd simulation of a pulsating heat pipe using ansys fluent. In order to address problems 2 4, this paper proposes a hydrogen pulsating heat pipe. Pdf cfd simulation of a pulsating heat pipe using ansys. Design, fabrication and performance evaluation of pulsating. Sreenivasa rao et al, numerical analysis of performance of closed loop pulsating heat pipe.
In this literature focus is on pulsating heat pipes phps. Pdf on jan 1, 2014, manzoni m and others published toward a design of a micro pulsating heat pipe find, read and cite all the research you need on. There are many parameters that affect performance of closed loop pulsating heat pipe clphp. Numerical study on flow and heat and mass transfer in.
This results in a natural, uncontrolled, asymmetric liquidvapor, plugbubble distribution in its tube sections, due to the dominance of surface tension forces. Heat pipe operating principles pressure drops operating temperature functional types of heat pipes heat pipe operating characteristics heat pipe design and selection design considerations mostly for vendors selecting heat pipes as part of thermal control system and. Computational model of miniature pulsating heat pipes. 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. 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 tubing is only partially filled with its working fluid.
Aug 26, 2018 understand if heat pipes or vapor chambers might benefit your application. Schematic of a pulsating heat pipe and its design variations 2. Heat pipes were developed in the 1960s, motivated by the space program, as a passive device no external energy supply is required capable of high heat transfer rates. It is simple in structure with a coil filled with certain working fluid in it and extended from the heat source to sink. 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. Pdf closed loop pulsating heat pipe rasel a sultan academia. 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. Pdf embedded pulsating heat pipe radiators semantic scholar. Practical designs of pulsating heat pipes adapted from 14.
Advances and unsolved issues in pulsating heat pipes. 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. Visualization of bubble mechanism of pulsating heat pipe with. Indian institute of technology kanpur, kanpur up 208016 india. So far there is no general formulation which can foretell the complex and chaotic flow nature for every working fluid. Conclusions pulsating heat pipe panels hpp were tested to be sure they are useful for the electronic components cooling and sorption machines thermal control. Schematic of pulsating heat pipe and its design variations from an introduction to pulsating heat pipe by manfred groll et. Pdf design of a hydrogen pulsating heat pipe researchgate. Design parameters of pulsatingoscillating heat pipe. Peregrine embeds pulsating heat pipes within the plane of flat sheetsplates by using printed circuit board technology to micromachine the channels.
These can be summarized as the tube diameter, input heat flux. Oscillating heat pipes ohp, also referred to as pulsating heat pipes php, are a relatively new development in the field of heat pipe technology. The pulsating heat pipe assisted tool holder was designed and fabricated. Everincreasing power densities in semiconductor electronics continue to motivate improvements to heat pipe design. A closedloop pulsating heat pipe php, also called oscillating heat pipe, ohp usually consists of a sealed, meandering channel connected endtoend. Pdf toward a design of a micro pulsating heat pipe.
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. Even the name is heat pipe,but working is very much different than the conventional heat pipes. Many of the present days electronic devices require cooling beyond the capability of conventional metallic heat sinks. Dec 02, 2019 numerical simulation was performed to establishing a twodimensional pulsating heat pipe model, to investigate the flow and heat transfer characteristics in the pulsating heat pipe by using the mixture and euler models, which were unsteady models of vaporliquid twophase, based on the controlvolume numerical procedure utilizing the semiimplicit method. 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. A pulsating heat pipe php 1 is a passive and extremely efficient way of exchanging heat between a hot source and a cold one. The working fluid transfer by means of differential pressure across vapour plugs from evaporator to condenser and back. Learn the similarities and differences between heat pipes and vapor chambers. Thermal performance of closed loop pulsating heat pipe using. There may exist an optional adiabatic zone in between evaporator and condenser.
The inside diameter of the tube is sufficiently small critical bo. An introduction to pulsating heat pipes electronics cooling. A pulsating heat pipe system surrounded by metal foam and inserted into a metal box filled with paraffin wax. 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. A comprehensive theory of operation and design tools. Based on the analysis presented, the system was able to preheat the inlet air by 8 c with an effectiveness of the system near 0. A typical configuration for a conventional heat pipe chp. The pulsating heat pipe consists of a closed loop serpentine channel, embedded in a multilayer, rectangular. Heat pipe can be differentiate on the basis of wick structure as wick heat pipe and wickless heat pipes,in wickless category there are thermosyphon and pulsating heat pipes.
Such a twophase system usually has a small vapor quality and typically presents a sequence of internal vapor. The heat pipe temperature reaches the water temperature in about 25 seconds, while the copper rod reaches just 30c after 200 seconds. Paper open access design and operation of a cryogenic. Heat pipes hardware m t l l i t b ith th i fmetal aluminum tube with grooves on the inner surface cold t ild extrusion grooves are filled with the working fluid water, ammonia, propylene, etc.
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. Different response of working fluids and their distinct flow nature as well as their behavior can be visualized which thereby helps to understand the. Experimental investigations on the thermal performance of a. Recent advances in electronics design and manufacturing have resulted in significant increases in heat flux density through a miniaturization of components and a simultaneous increase in power requirements associated with improved product. Feb 05, 2018 its the two phase heat transfer device suitable for low power applications such as electronic cooling. Pulsating hpp are potentially cheaper than conventional wicked heat pipe panels. As with any design process, many of the decisions that must be taken are interrelated and the process is iterative. Each of these processes has proven feasibility and used together can readily produce mephps. On the design fundamentals of pulsating heat pipes.
Design and operation of a cryogenic nitrogen pulsating heat pipe to cite this article. Pdf toward a design of a micro pulsating heat pipe marco. As relatively new and promising members of the wickless heat pipe family, pulsating heat pipes phps, with high effective thermal conductivity and construction simplicity, may answer to the present industrial demand of efficient thermal control, flexibility and low costs. The details of the experimental setup are introduced as follows. Afterwards mostly qualitative and some quantitative. Jul 22, 2019 this paper describes the experimental investigations conducted on a closed loop pulsating heat pipe clphp for assessing the thermal performance. They differ by their geometry and a mechanism of fluid transport inside the heat pipe. 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. Jul 09, 2015 fluid phase change applications, often referred to as recirculating, use closed loop heat pipes to transfer heat quickly through evaporation and condensation within the heat pipe. Oscillating heat pipes ohps have high heat spreading performance and are capable of removing higher heat fluxes. For various reasons a closed loop pulsating heat pipe clphp is thermally a better option than an open loop device.
Operation the device is first evacuated and subsequently filled up partially with a pure working fluid. The design of a hydrogen pulsating heat pipe the first step to design a pulsating heat pipe experimental setup is to determine the working temperature, which. Pulsating heat pipe is a kind of highly efficient heat conductor in which the latent heat of evaporation is used to transport great amounts of heat in the presence of only small differences in temperature. Design case study pulsating heat pipe for microgravity.
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