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. It can transfer the heat without any moving parts so that the heat pipe is calm, noise free. Hence, other than thermal design of the heat pipe, mechanical design of the. 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. Outlets should be located to distribute the air as uniformly as possible throughout the room. In general, heat always flows from warmer to cooler surfaces. 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 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. Therefore to reduce the wastage of energy in form of heat, furnaces, and pipes carrying fluids at elevated temperature and turbines are insulated.
Figure 3 basic principle of an oscillating heat pipe ohp 5. The original heat pipe operating principle was developed by richard s. At this stage the student can begin to apply knowledge of mathematics and computational methods to the problems of heat transfer. Beginning with a definition of the problem, including the temperature difference and the heat flow which has to be.
Heat pipes operating principles heat input wick heat output vapor flow typical use of heat pipe. Basic principles of heat pipes and history springerlink. 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. Karl ponweiser institute for thermodynamics and energy conversion vienna university of technology vienna, austria published by wseas press. The heat pipe was charged with potassium as the working fluid, wicked by a stainless steel wiremesh, and the case material was inconel. Heat pipe is a capillary twophase heat transfer device. Heat up the heating end of the heat pipe emperature 700c and dissipate 5 6. At this stage the student can begin to apply knowledge of mathematics and computational methods to. The number one concern in evaluating the air distribution in a space is the comfort of the occupants. Heat pipes a novel cooling principle for generator circuit.
A variety of liquids and wicks are used to make a heat pipe, but the principle is the same. Users manual for heat pipe fluid properties program. They work on the principle of the heat capacity of water and a wick. Heat pipe is a high performance heat transmission device with an extremely high thermal conductivity. Heat pipe principles use 2 phase flow, latent heat of vaporization, and capillary action to circulate a working fluid. What is a heat pipe heat pipes basics and technology. Heat pipe facilitates the applications when dehumidification is needed and increases system efficiency. It is called a doublepipe exchanger because one fluid flows inside a pipe and the other fluid flows between that pipe and another pipe that surrounds the first. Adiabatic temperature of heat pipe, measurement on heat pipe top side. The main applications of heat pipes deal with the problems of environmental protection and energy and fuel savings. Plate heat exchanger, how it works working principle hvac industrial engineering phx heat transfer duration. Heat pipes are used in laptop computers and other devices for cooling. Beginning with a definition of the problem, including the temperature. The application of heat pipes should be considered when the thermal design is either conduction limited or when nonthermal goals such as weight cannot be achieved with other materials such as solid aluminum andor copper.
Heat pipe technology may play a decisive role in improving the overall economics, and public perception on nuclear desalination, specifically on seawater desalination. The normal air velocity used for comfortable air distribution is 50 fpm. Horseshoe heat pipe for dehumidificationtubes friterm. Principles of finnedtube heat exchanger design for enhanced heat transfer 2nd edition by. 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. Heat pipes gaugler proposed the principle of heat pipe in 1942 for refrigeration engineering applications. Heat pipes heat transport limit for proper heat pipe operation, the total pressure drop must not exceed its capillary pressure head. It can be easily mounted in an airconditioning system. The vapor then travels along the heat pipe to the cold. Furnaces and refractories fusion dust and slag or by the action of alkalies on fireclay refractories, to form alkalialumina silicates.
Even though a heat pipe has a big potential to remove the thermal energy from a high heat flux source, the heat removal performance of heat pipes cannot be predicted well since a first principles of evaporation has not been established. Thermosiphon or thermosyphon is a method of passive heat exchange, based on natural convection, which circulates a fluid without the necessity of a mechanical pump. 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. Efficient heat transferefficient heat transfer boiling and condensationboiling and condensation small temperature difference between the heat source and. 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. A furnace is an equipment used to melt metals for casting or to heat materials to change their shape e. Pdf heat pipes a novel cooling principle for generator.
What is thermal insulation insulation is defined as a material or combination of materials, which retard the flow of heat. Heat pipe principle it is not within the scope of the article to go into details of heat pipe theory. Plate heat exchanger applications and working principle. Potential of heat pipe technology in nuclear seawater. Thermosiphoning is used for circulation of liquids and volatile gases in heating and cooling applications such as heat pumps, water heaters, boilers and furnaces. The heat pipe is one of the remarkable achievements of thermal physics and heat transfer engineering in this century because of its unique ability to transfer heat over large distances without considerable losses. Intermediate heat transfer, a second course on heat transfer for undergraduate seniors and beginning graduate students. The heat pipe radiator characteristics were analysed and compared with a pumped loop radiator using numerical calculations. In this guide, the term plastic pipes is used to cover all of these pipes, unless otherwise explained. A heat pipe is a selfcontained structure which achieves very high thermal conductance by means of twophase fluid flow with capillary circulation. Thermalfluids central is an online, free access eglobal center for heat and mass transfer, thermodynamics, fluid mechanics, combustion, and multiphase systems. The doublepipe heat exchanger is one of the simplest types of heat exchangers. This section introduces furnaces and refractories and explains the various design and operation aspects.
Space for the vapour travel is provided inside the tank. Heat pipe working principle seminar projects topics. Compared to a conventional cooling coil, it has a higher depth. Heat pipes a novel cooling principle for generator.
In this section we will briefly describe the basic working principle and the performance limits of heat pipes. For the heat pipe designs which have found the widest application, viz. It is amazing how quickly heat transfers in the heat pipe and how slowly it transfers in the solid copper. Jul 07, 2017 plate heat exchanger, how it works working principle hvac industrial engineering phx heat transfer duration.
Heat pipes, electronic cooling, wick structure, working fluids, computer. A rule of thumb for the effective thermal conductivity of a heat pipe is 4000 wmk. 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. Ats engineering ebook advanced thermal solutions, inc. Sorption heat pipe could be used as a sorption heat transfer element and be cooled and heated as a heat pipe. The liquid evaporates into a gas that travels to the cooler end of the pipe, condenses back into liquid. Principles of finnedtube heat exchanger design for enhanced heat transfer 2nd edition by dipl. Haringx 10 modeled the bellow as the combination of annular plates connected by elastic cylinders and derived. Plate heat exchanger applications and working principle hvac. Pdf the heat pipe is one of the remarkable achievements of. Heat pipe 1piece vapor chamber 2piece vapor chamber 20 heat pipes bend radius 3x diameter of heat pipe. The main length of the heat pipe can be divided into three parts vz evaporator section, an adiabatic section and the condenser section.
Heat pipes are hermetically sealed tubes containing a working fluid in both the liquid and vapour phases and a wick to allow for the return of the condensed working fluid to the evaporator, fig. The ball is free to move between the valve seat and stopper, but when it is in contact with. 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. In the short heat pipe extreme 34 length, this effect is nearly zero, so please consult with wakefieldvette engineers to find the right solution for your application. When selecting the diameter and length of heat pipe it is important to consider the orientation with respect to gravity. This applied force joins the melted surfaces resulting in a permanent, monolithic fusion joint. Where ambient temperatures are suitable for heat pipes, they are the most efficient method of cooling as the waste heat is the engine which drives the system. Heat pipe engineering ebook advanced thermal solutions. When coupled to the lowtemperature multieffect distillation process, heat pipes could effectively harness most of the waste heat generated in various types of nuclear power.
Heat pipe can be manufactured as a compact unit with cooling coil. Refrigerant flow control is the key to many advantages as well as the. 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. Furnaces and refractories break free from excessive melting. Heat pipes are referred to as the superconductors of heatdue to their fast transfer capability with low heat loss. The application of heat pipes should be considered when the thermal design is either conduction limited or when nonthermal goals such as weight cannot be achieved with other materials such as solid alum. Allows direct contact with heat source 1piece vapor chamber 10mm bend radius along. How heat recovery wheel or heat pipe compatible with ahu. It utilizes latent heat of evaporation of the working fluid to transmit heat from one point to another along the length of the heat pipe with a very small temperature gradient. Research paper thermomechanical design and characterization of. 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. Design considerations when using heat pipes electronics cooling.
In order to understand how insulation works, it is important to understand the concept of heat flow or heat transfer. The only power requirement is to operate two circulating fans or blowers. The working principle, the fluid flow and heat transfer mechanism are similar in any heat pipe irrespective of the shape. Evaporator temperature of heat pipe, measurement on heat pipe top side. External power is required for temperature control. Thermalfluids central free online resource for heat.
It is a common practice to include a slight excess of working fluid over and above that required to saturate 147. 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. This book provides a practical study of modern heat pipe engineering, discussing how it can be optimized for use on a wider scale. This flow does not stop until the temperature in the two surfaces is equal. The operational principles and the performance characteristics of the different types of heat pipes are described. Hvac heat exchangers explained the basics working principle how heat. Energuide is the official government of canada mark associated with the labelling and rating of the.
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. Heating and cooling with a heat pump produced by natural resources canadas office of energy efficiency energuide the heating and cooling series is published by the energuide team at natural resources canadas office of energy efficiency. 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. Thermomechanical design and characterization of flexible. Use 2 phase flow, latent heat of vaporization, and capillary action to circulate a. Heat fusion the principle behind heat fusion is to heat two surfaces to a designated temperature, and then fuse them together by application of the required force. Pipes are generally available in nominal diameters of 10mm to 110mm in straight lengths or coils. Design considerations when using heat pipes electronics. Qmax customer requirement then heat pipe is passed test frequency.
Pdf basic principles of heat pipes and history researchgate. Power generation using heat pipe thermoelectric module. However, his principle was not effectively applied and was not widely known until 1963, when grover and his colleagues developed heat pipes for space applications and described the concept with the name of heat pipe. Operating temperature depends on heat load, sink temperature, and surrounding temperature. A loop heat pipe with coherent pores integrated to the heat source is considered as a calculation model in this paperfig.
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