Discussion: “Analysis of Asymmetric Disk-Shaped and Flat-Plate Heat Pipes” (Vafai, K., Zhu, N., and Wang, W., 1995, ASME J. Heat Transfer, 117(1), pp. 209–218)

2014 ◽  
Vol 136 (11) ◽  
Author(s):  
Kyu Han Kim ◽  
Seung-Hyun Lee ◽  
Hyun Jin Kim ◽  
Seok Pil Jang
Keyword(s):  
Heat Transfer ◽  
Flat Plate ◽  
Heat Pipes ◽  
Plate Heat

Experimental investigation of the novel BIPV/T system employing micro-channel flat-plate heat pipes

2018 ◽  
Vol 39 (5) ◽  
pp. 540-556 ◽  
Author(s):  
Zhangyuan Wang ◽  
Zicong Huang ◽  
Fucheng Chen ◽  
Xudong Zhao ◽  
Peng Guo
Keyword(s):  
Heat Transfer ◽  
Flat Plate ◽  
Water Flow ◽  
Thermal Energy ◽  
Thermal Efficiency ◽  
Heat Pipes ◽  
Micro Channel ◽  
Plate Heat ◽  
Electrical Efficiency ◽  
T System

In this paper, the micro-channel flat-plate heat pipes-based BIPV/T system has been proposed, which is expected to have the characteristics, e.g. reduced contact thermal resistance, enhanced heat transfer area, improved heat transfer efficiency and building integration. The proposed system was constructed at the laboratory of Guangdong University of Technology (China) to study its performance. The temperatures of the glass cover, PV panel, micro-channel flat-plate heat pipes, and tank water were measured, as well as the ambient temperature. The thermal and electrical efficiency was also calculated for the system operated under the conditions with different simulated radiations and water flow rates. It was found that the proposed system can achieve the maximum average overall efficiency of 50.4% (thermal efficiency of 45.9% and electrical efficiency of 4.5%) for the simulated radiation of 300 W/m2 and water flow rate of 600 L/h. By comparing the proposed system with the two previous systems employing the conventional heat pipes, the thermal efficiency of the proposed system was clearly improved. The research will develop an innovative BIPV/T technology possessing high thermal conduction capability and high thermal efficiency compared with the conventional BIPV/T system, and helps realise the global targets of reducing carbon emission and saving primary energy in buildings. Practical application: This novel BIPV/T employing micro-channel flat-plate heat pipes will be potentially used in buildings to provide amount of electricity and thermal energy. The generated electricity will be used by the residents for electrical devices, and the thermal energy can be used for hot water, even for space heating and cooling.

Thermal Performance of a Flat Plate Heat Pipe With Gradient Wettability

2013 ◽  
Author(s):  
Ping-Hei Chen ◽  
Hung-Hsia Chen ◽  
Bo-Rui Huang ◽  
Long-Sheng Kuo
Keyword(s):  
Heat Transfer ◽  
Flat Plate ◽  
Heat Pipe ◽  
Thermal Performance ◽  
Heat Pipes ◽  
Contact Angles ◽  
Plate Heat ◽  
Flat Plate Heat Pipe ◽  
Superhydrophilic Surface ◽  
Gradient Surface

Many studies have been performed on the flat-plate heat pipes with sintered wick. It was found that during the evaporation process, the heat transfer characteristics of hydrophilic surface performed better than hydrophobic surface. This work investigated the heat transfer characteristics of flat-plate heat pipes in which the bottom surface was modified with various gradient contact angles by a sol-gel method. This method was applied to create a gradient surface on copper-plate surface. The coated nanoparticles were immobilized on the surface after the surface was heated in a furnace at a working temperature of 120°C. The thermal resistance results of flat plate heat pipes with either homogeneous superhydrophilic surface or a gradient wettability are reported in this study. For the gradient wettability, the evaporation region was super-hydrophilic and the condense region was super-hydrophobic. The heat transfer ability was both increased in evaporation region and condense region. Furthermore, the reflux ability of the working fluid was performed better due to the unbalanced surface tension on the gradient surface and the impact of gravity force of inclination angle (α). By manipulating different surfaces with different contact angles (gradient surface, contact angle = 150 ° /110 ° /20 ° /10 ° and uniform surface, contact angle <10°) and different inclination angles (α = 0°, 10°), we managed to find the better combination to improve the thermal performance of flat-plate heat pipe. The results indicated that the thermal performance of flat plate heat pipe with a gradient wettability is better than homogeneous superhydrophilic surface. The evaporation resistance of gradient wettability surface (gradient & α = 10°) has achieved to 0.098 °C /W, and reduced 30% than homogenous superhydrophilic surface (CA <10° & α = 0°). The gradient wettability surface in this work performed as well as the traditional sintered wick flat-plate heat pipe.

Three-dimensional heat transfer analysis of flat-plate oscillating heat pipes

2021 ◽  
pp. 117189
Author(s):  
Kimihide Odagiri ◽  
Kieran Wolk ◽  
Stefano Cappucci ◽  
Stefano Morellina ◽  
Scott Roberts ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Flat Plate ◽  
Three Dimensional ◽  
Heat Pipes ◽  
Heat Transfer Analysis

Analisis Perbandingan Jenis Material Penukar Kalor Plat Datar Aliran Silang Untuk Proses Pengeringan Kayu

2021 ◽  
Vol 9 (1) ◽  
pp. 60-71
Author(s):  
Abeth Novria Sonjaya ◽  
Marhaenanto Marhaenanto ◽  
Mokhamad Eka Faiq ◽  
La Ode M Firman
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Flat Plate ◽  
Heat Exchangers ◽  
Fluid Dynamic ◽  
Cross Flow ◽  
Plate Heat ◽  
Dry Air ◽  
Copper Material ◽  
Plate Type

The processed wood industry urgently needs a dryer to improve the quality of its production. One of the important components in a dryer is a heat exchanger. To support a durable heat transfer process, a superior material is needed. The aim of the study was to analyze the effectiveness of the application of cross-flow flat plate heat exchangers to be used in wood dryers and compare the materials used and simulate heat transfer on cross-flow flat plate heat exchangers using Computational Fluid Dynamic simulations. The results showed that there was a variation in the temperature out of dry air and gas on the flat plate heat exchanger and copper material had a better heat delivery by reaching the temperature out of dry air and gas on the flat plate type heat exchanger of successive cross flow and.   overall heat transfer coefficient value and the effectiveness value of the heat exchanger of the heat transfer characteristics that occur with the cross-flow flat plate type heat exchanger in copper material of 251.74725 W/K and 0.25.

Experimental Study of Turbulent Flow Heat Transfer and Pressure Drop in a Plate Heat Exchanger With Chevron Plates

1999 ◽  
Vol 121 (1) ◽  
pp. 110-117 ◽  
Author(s):  
A. Muley ◽  
R. M. Manglik
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Flat Plate ◽  
Plate Heat Exchanger ◽  
Plate Heat ◽  
Experimental Heat ◽  
Experimental Heat Transfer ◽  
Flow Heat ◽  
Phase Water

Experimental heat transfer and isothermal pressure drop data for single-phase water flows in a plate heat exchanger (PHE) with chevron plates are presented. In a single-pass U-type counterflow PHE, three different chevron plate arrangements are considered: two symmetric plate arrangements with β = 30 deg/30 deg and 60 deg/60 deg, and one mixed-plate arrangement with β = 30 deg/60 deg. For water (2 < Pr < 6) flow rates in the 600 < Re < 104 regime, data for Nu and f are presented. The results show significant effects of both the chevron angle β and surface area enlargement factor φ. As β increases, and compared to a flat-plate pack, up to two to five times higher Nu are obtained; the concomitant f, however, are 13 to 44 times higher. Increasing φ also has a similar, though smaller effect. Based on experimental data for Re a 7000 and 30 deg ≤ β ≤ 60 deg, predictive correlations of the form Nu = C1,(β) D1(φ) Rep1(β)Pr1/3(μ/μw)0.14 and f = C2(β) D2(φ) Rep2(β) are devised. Finally, at constant pumping power, and depending upon Re, β, and φ, the heat transfer is found to be enhanced by up to 2.8 times that in an equivalent flat-plate channel.

Experimental and Statistical Analysis of MgO Nanofluids for Thermal Enhancement in a Novel Flat Plate Heat Pipes

2017 ◽  
Vol 17 (01n02) ◽  
pp. 1760018 ◽  
Author(s):  
P. Pandiaraj ◽  
A. Gnanavelbabu ◽  
P. Saravanan
Keyword(s):  
Thermal Conductivity ◽  
Flat Plate ◽  
Volume Fraction ◽  
Heat Pipes ◽  
Influential Factors ◽  
Working Fluid ◽  
Particle Fraction ◽  
Solution Ph ◽  
Plate Heat ◽  
Xrd Techniques

Metallic fluids like CuO, Al2O3, ZnO, SiO2 and TiO2 nanofluids were widely used for the development of working fluids in flat plate heat pipes except magnesium oxide (MgO). So, we initiate our idea to use MgO nanofluids in flat plate heat pipe as a working fluid material. MgO nanopowders were synthesized by wet chemical method. Solid state characterizations of synthesized nanopowders were carried out by Ultraviolet Spectroscopy (UV), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) techniques. Synthesized nanopowders were prepared as nanofluids by adding water and as well as water/ethylene glycol as a binary mixture. Thermal conductivity measurements of prepared nanofluids were studied using transient hot-wire apparatus. Response surface methodology based on the Box–Behnken design was implemented to investigate the influence of temperature (30–60[Formula: see text]C), particle fraction (1.5–4.5 vol.%), and solution pH (4–12) of nanofluids as the independent variables. A total of 17 experiments were accomplished for the construction of second-order polynomial equations for target output. All the influential factors, their mutual effects and their quadratic terms were statistically validated by analysis of variance (ANOVA). The optimum stability and thermal conductivity of MgO nanofluids with various temperature, volume fraction and solution pH were predicted and compared with experimental results. The results revealed that increase in particle fraction and pH of MgO nanofluids at certain points would increase thermal conductivity and become stable at nominal temperature.

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