Nanofluids as Working Media for Loop Heat Pipes (original) (raw)
Related papers
IOP, 2018
The thermal performance of a loop heat pipe (LHP) with alumina water nanofluid is experimentally investigated. The experiments are carried out in a LHP, in which the setup consists of condenser, evaporator, two transport lines (vapour and liquid lines), rotameter, power supply, thermocouples. The experiments are conducted for heat input ranging from 30 310 W using deionised water (baseline) and alumina water nanofluid. Alumina nanoparticles with 2% mass concentration and water are used as working fluids. The experimental results indicate that the nanofluid can enhance the thermal performance of loop heat pipe and lower the evaporator temperature by 12 % from the baseline case. The experimental results prove the capability of loop heat pipe with alumina water nanofluid for various applications.
Effect of structural character of gold nanoparticles in nanofluid on heat pipe thermal performance
Materials Letters, 2004
Nanofluid is employed as working medium for conventional circular heat pipe. The nanofluid used in the present study is an aqueous solution of various-sized gold nanoparticles. The thermal resistance of heat pipe with nanofluid or with DI water was measured. The heat pipe was designed as a heat spreader for CPU in a notebook or a desktop PC. At a same charge volume, there is a significant reduction in thermal resistance of heat pipe with nanofluid as compared with DI water. The measured results also show that the thermal resistance of a vertical meshed heat pipe varies with the size of gold nanoparticles. D
A comprehensive study of the performance of a heat pipe by using of various nanofluids
Science Direct, 2017
In this paper, a two-dimensional numerical model is developed to simulate the performance of a heat pipe using various nanofluids. The effect of different nanofluids (prepared using alumina, copper oxide, and silver nanoparticles) at different concentrations and particle diameters on the performance of heat pipe is also studied by through finite volume method. The obtained results show that using a nanofluid instead of water leads to the increased thermal efficiency and reduction in heat at wall of the heat pipe. Also, the temperature difference between the evaporator and the condenser is a function of input power; this means that by an increase in the input capacity, the temperature difference between the evaporator and the condenser increases. It was observed that the use of nanofluid reduces the axial-flow pressure of the fluid inside the wick. As a result, the transmission of fluid flow inside the wick from the condenser to the evaporator is easily done with the cost of using a nanofluid. Moreover, with an increase in thermal capacity, fluid pressure drop becomes maximum and thus temperature difference between the evapora-tor and the condenser increases.
Enhancement of the thermal performance of a loop heat pipe using silica-water nanofluid
IOP, 2019
Loop heat pipes (LHPs) are heat transfer devices which are capable of transferring large amount of heat energy over long distances. This paper presents the results of numerical investigations carried out to determine the effect of silica-water nanofluid on the thermal performance of a LHP. Silica-water nanofluid at 2 % nanoparticle concentration and deionised water are considered as working fluids. The power input is varied from 40 to 320 W in steps of 40 W. The numerical results are validated with experimental data available in the literature. LHP using deionsed water is used as the baseline case. The results shows that silica-water nanofluid can significantly enhance the thermal performance of the LHP when compared with the baseline case. The evaporator temperature of LHP using nanofluid reduced by 27 % than the baseline case. The LHP attained steady state faster (150 s earlier) with the presence of silica nanoparticles due to enhanced thermal properties. Thus silica-water nanoflu...
www.journals.saintgits.org Review paper A Review of Performance of Heat Pipe with Nanofluids
2016
Copyright © 2014 IJRIST. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. With the modern era of miniaturization of equipments, heat pipes have attracted major attention in the field of heat transfer. Nanofluids also have attracted a notable attention in recent days due to its superior heat transport properties. This review aim to compile the effect of nanofluid in heat pipes. Performance of different nanoparticles and different base-fluids are investigated. Most of the papers reviewed here reported an enhancement in performance of heat pipes. Existence of an optimum concentration of nanoparticles in base fluid was also reported. Paper also presents a perspective on possible research application.
A Review of Performance of Heat Pipe with Nanofluids
With the modern era of miniaturization of equipments, heat pipes have attracted major attention in the field of heat transfer. Nanofluids also have attracted a notable attention in recent days due to its superior heat transport properties. This review aim to compile the effect of nanofluid in heat pipes. Performance of different nanoparticles and different base-fluids are investigated. Most of the papers reviewed here reported an enhancement in performance of heat pipes. Existence of an optimum concentration of nanoparticles in base fluid was also reported. Paper also presents a perspective on possible research application.
Evaluation of Heat Transfer Mechanisms in Heat Pipe Charged with Nanofluid
Arabian Journal for Science and Engineering, 2019
The nanofluid is a colloidal solid-liquid mixture obtained by the dispersing nanoparticles with a high heat transfer coefficient in the base fluid. In general, metal, metal oxide, ceramic and magnetic nanoparticles are used in nanofluids. The nanoparticles suspended in the base fluid of heat pipes effectively increased the heat transfer rate and thermal conductivity properties of the base fluid. The nanofluids have been found to be acting much better for some problems such as sedimentation, erosion, clogging and pressure drop compared to common slurries. The energy transfer is carried out by two-phase heat transfer mechanism in heat pipes. There are many parameters and factors that have an effect in the boiling heat transfer coefficient. It is not easy to understand the positive and negative changes caused by nanofluids in this complex heat transfer mechanism. The surface geometry is a significant indicator on the boiling heat transfer mechanism. Investigation into nanofluid effects besides the surface geometry is very important in the experimental studies. In addition, it is known that nanofluids change the properties of the heater surface, apart from the thermophysical properties. The synthesis methods of nanofluids are presented in this article. Then, the physical and chemical mechanisms determining the long-term stability of nanofluids are explained in detail. Finally, some useful information about the use of nanofluids in heat pipes and pool boiling of nanofluids is given. The presented study also describes the pool boiling mechanism of nanofluids to understand the positive effects of nanofluids on the heat pipes heat transfer mechanism.
INVESTIGATION ON THERMAL PERFORMANCE OF HEAT PIPE USING NANOFLUID: A REVIEW
IJAERD, 2018
Nanofluids have been the subject of intensive study worldwide since pioneering researchers recently discovered the anomalous thermal behaviour of these fluids. Comprehensive research work on heat transfer in heat pipe using nanofluids have been experimentally and theoretically investigated in recent years by various researchers. The suspended nanoparticles effectively enhance the heat transfer characteristics and the transport properties of base fluids in heat pipes. The objective of this paper is to present an overview of literature dealing with influence of various factors such as heat pipe tilt angle, charged amount of working fluid, nanoparticle type, size and concentration, mass/ volume fraction & its effect on the thermal efficiency, heat transfer capacity & reduction in thermal resistance.
Effect of Nanofluid Concentration on the Performance of Circular Heat Pipe
The goal of this paper is to experimentally study the behavior of nanofluid to improve the performance of a circular heat pipe. Pure water and Al2O3-water based nanofluid are used as working fluids. An experimental setup is designed and constructed to study the heat pipe performance under different operating conditions. The effect of filling ratio, volume fraction of nano-particle in the base fluid, and heat input rate on the thermal resistance is investigated. Total thermal resistance of the heat pipe for pure water and Al2O3-water based nanofluid is also predicted. An experimental correlation is obtained to predict the influence of Prandtl number and dimensionless heat transfer rate, Kq on thermal resistance. Thermal resistance decreases with increasing Al2O3-water based nanofluid compared to that of pure water. The experimental data is compared to the available data from previous work. The agreement is found to be fairly good.
Investigation of the effects of base fluid type of the nanofluid on heat pipe performance
Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy, 2020
Most recently, an ascending tendency in nanoparticles containing working fluid utilization has been observed in such thermal systems as double pipe heat exchangers and thermosiphons in so far as its advantages upon the performance of such systems. In order to investigate how the type of the base fluid affects the nanofluid’s properties used for thermal applications, an experimental test rig was setup and two different nanofluid each of which involves different base fluid, but same nanoparticles and surface active agent were tested. During the nanofluid preparation process, bauxite nanoparticles as nanoparticle material and sodium dodecyl benzene sulfonate as surface active agents were used in volume fractions of 2% and 0.5%, respectively. As the base fluid type, ethylene glycol and deionized water were utilized. The tests were conducted under diverse working conditions and vacuum pressure. Distribution of temperature ahead the heat pipe wall, efficiency and heat pipe’s thermal resis...