Experimental Study of Filling Ratio Effect on the Thermal Performance in a Multi-Heat Pipe with Graphene Oxide/Water Nanofluids (original) (raw)
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Heat Transfer Performance of a Multi-heat Pipe Using Graphene Oxide/Water Nanofluid
Journal of Energy and Power Engineering
A multi-heat pipe is a device for heat transmission. It is composed of a heating section, a cooling section and an adiabatic section. The heating and cooling sections are the same and both are connected by four circular parallel tubes. This experimental study is performed to investigate heat transfer performance of a multi-heat pipe in the vertical orientation using pure water and GO (graphene oxide)/water nanofluid. GO/water nanofluids were synthesized by the modified Hummers method with 0.05%, 0.1%, 0.15%, and 0.2% volume concentrations. The thermal performance has been investigated with varying heat flux in the range of 10-30 W and 100% fill charge ratio. Wall temperature, thermal resistance, and heat transfer coefficient of the heat pipe are measured and compared with those for the heat pipe using pure water. The experimental results show that the evaporator wall temperature with GO nanofluid is lower than that of the base fluid. Also, the heat pipe that charged with nanofluids showed lower thermal resistance compared with pure water. Heat transfer enhancement is caused by suspended nanoparticles and is pronounced with the increase in particle volume fraction.
The Experimental Study of the Thermal Performance of Heat Pipe using CuO/Water Nanofluid.
International Journal of Engineering Sciences & Research Technology, 2013
This paper presents the enhancement of the thermal performance of a heat pipe charged with nanofluid. The CuO/Water nanofluid served as the working fluid with three concentrations by volume 1g/L, 5g/L and 10g/L in heat pipe. The heat pipe is fabricated by a straight copper tube with an outer diameter 18 mm, thickness 1mm and length of 475 mm. This paper presents a discussion on the effect of various performing parameters by varying different heat inputs as well as fluid concentration as mentioned above. The nanoparticles have observed significant effect on the enhancement of thermal performance of heat pipe by increasing fluid concentration as well as different heat inputs. Experimental results show that at a heating power of 80 W, the optimal thermal conductivity and heat transfer rate for CuO/Water nanofluid heat pipe are 50.46% and 1.75% respectively, which are better than that of pipes using pure water as the working fluid. Nomenclature: dx: Thickness (m) dT: Temperature difference ( 0C ) k: Thermal conductivity [W/m K] R HP : Total thermal resistance (ᶿC/W) A s : Surface Area (m 2 ) V HP : Total Volume of heat pipe (L) D: Outer diameter (m) t: Thickness (m) k HP : Overall thermal conductivity of heat pipe (W/m 0 C) L: Length of the heat pipe (m) Qin: Heat transfer rate (heating power) (W) V: Voltage (V)
2024
In response to rising power demands and cooling loads in thermal systems, new technologies have been adopted to enhance heat transfer characteristics. A suspended nanosized particle that has high thermal conductivity in conventional heat transfer fluids is called a nanofluid. Several studies have investigated the effects of graphene-based nanofluids on thermophysical parameters such as thermal conductivity and viscosity. The paper also highlighted potential benefits of nanofluid in terms of energy conservation, reduction of material consumption and sustainability in the preparation of high thermal conductivity fluid. Also, many numerical and experimental studies have been done for heat transfer characteristics using different graphene-based nanofluids. This review examines the preparation, thermophysical properties, and heat transfer characteristics of graphene-based nanofluids, including graphene nanoplatelets, graphene oxide, and graphene composites, across various thermal systems.
International Communications in Heat and Mass Transfer, 2018
Pulsating heat pipes (PHPs) are heat transfer devices which are widely utilized in electronic devices and energy systems. Improvement in thermal performance of PHPs will lead to higher heat transfer capacity and enhancement in the efficiency of systems which PHPs are applied. In this study, an experimental investigation was performed on the thermal performance of a pulsating heat pipe by applying graphene oxide nanofluid as working fluid. Four concentrations of graphene oxide (0.25, 0.5, 1, and 1.5 g/lit) in water as base fluid were used in the PHP. Results indicate that adding graphene oxide sheets increased thermal conductivity and viscidity of the base fluid. Moreover, utilizing graphene oxide can decrease thermal resistance of PHP up to 42%. In addition, high concentration (1.5 g/lit) of the nanofluid worsen thermal performance of the PHP in comparison with pure water which is attributed to increase in dynamic viscosity of nanofluid. Finally, a regression model is proposed in order to compare effects of heat input and concentration of nanofluid on thermal resistance mathematically.
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.
Heat Transfer Enhancement in Heat Pipe Using Nanofluid – A Review
— For enhancement of heat transfer in heat pipe, Nano fluid found vital role and a new frontier in various engineering applications. This paper reviews and summarizes the work on heat pipes using nano fluids as a working medium. Various types of nano particle with different base fluids as proved its potential to improve thermal properties of working medium in heat pipe. The effect of filling ratio, volume fraction of nano practices on thermal performance in various kinds of heat pipe with different base fluids under various operating conditions has been discussed. Mechanism of enhancement of heat transfer after utilization of nano fluids in heat pipe has been explained. Also, influence of dimensionless on thermal resistance in terms of correlation has been studied. This paper discusses relativity of total heat resistance between the heat pipe with nano fluid and with existing fluids. Focusing towards the application this paper suggests the suitability of heat pipes in various heat generation problems.
2017
In this study, convective heat transfer of graphene oxide (GO)-distilled water (DW) nanofluid in a laminar flow through a circular copper tube with an inner diameter of 16 mm, a wall thickness of 2 mm, a length of 1830 mm and an uniform wall heat flux was investigated experimentally and numerically. In experimental investigation, it was evaluated the heat transfer characteristics and the pressure drop (head loss) of the GO-DW nanofluid when in numerical study, the finite volume method (ANSYS 15.0-FLUENT) was employed to solve the conservation equations in three dimensional domains by assuming single phase flow. The heat transfer coefficient and pressure drop (head loss) of DW used as a base fluid were measured and compared with the corresponding data from the correlation. The datas of nanofluid for surface temperature of the tube were satisfied within an about 2 % error for the numerical work compared with experimental results. The effects of the heat flux, volumetric concentration and flow rate on the enhancement of the heat transfer of GO-DW nanofluid were presented in the study. The enhancement value of convective heat transfer coefficient of the GO-DW with 0.02 % volumetric concentration and flow rate of 0.9 l/min. (Re=1118) was about 25 % for the heat flux value of 3043.94 W/m 2 (350 W) compared with DW. However, the max. increases in head loss and friction factor with 0.02 % GO-DW and 1.2 l/min were 8.78 % and 8.4 %, respectively. Finally, the results revealed that the GO-DW nanofluid can be used as a good alternative instead of conventional working fluids in heat transfer applications.
Frontiers in Materials
The optimization of heat transfer in heat exchanging equipment is paramount for the efficient management of energy resources in both industrial and residential settings. In pursuit of this goal, this empirical study embarked on enhancing the heat transfer performance of a double pipe heat exchanger (DPHX) by introducing silver (Ag)-graphene oxide (GO) hybrid nanofluids into the annulus of the heat exchanger. To achieve this, three distinct molar concentrations of Ag ornamented GO hybrid nanoparticles were synthesized by blending GO nanoparticles with silver nitrate at molarities of 0.03 M, 0.06 M, and 0.09 M. These Ag-GO hybrid nanoparticles were then dispersed in the base fluid, resulting in the formation of three distinct hybrid nanofluids, each with a consistent weight percentage of 0.05 wt%. Thorough characterization and evaluation of thermophysical properties were performed on the resulting hybrid nanomaterials and nanofluids, respectively. Remarkably, the most significant enha...
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.
A REVIEW ON HEAT TRANSFER ENHANCEMENT STUDIES OF HEAT PIPES USING NANOFLUIDS
Heat pipe is a special type of heat exchanger that transfers large amount of heat due to the effect of capillary action and phase change heat transfer principle. Recent development in the heat pipe includes high thermal conductivity fluids like nanofluids, sealed inside to extract the maximum heat. This paper reviews, influence of various factors such as heat pipe tilt angle, charged amount of working fluid, nanoparticles type, size, and mass/volume fraction and its effect on the improvement of thermal efficiency, heat transfer capacity and reduction in thermal resistance. The nanofluid preparation and the analysis of its thermal characteristics also have been reviewed.