Computational analysis of hybrid nanofluid enhanced heat transfer in cross flow micro heat exchanger with rectangular wavy channels

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.

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Computational Fluid Dynamics Evaluation of Heat Transfer Correlations for Sodium Flows in a Heat Exchanger

Journal of Heat Transfer ◽

10.1115/1.4000707 ◽

2010 ◽

Vol 132 (5) ◽

Cited By ~ 3

Author(s):

Seok-Ki Choi ◽

Seong-O Kim ◽

Hoon-Ki Choi

Keyword(s):

Heat Transfer ◽

Heat Exchanger ◽

Turbulence Model ◽

Numerical Solutions ◽

Numerical Study ◽

Cross Flow ◽

Turbulence Models ◽

Parallel Flow ◽

Sst Model ◽

Heat Transfer Correlations

A numerical study for the evaluation of heat transfer correlations for sodium flows in a heat exchanger of a fast breeder nuclear reactor is performed. Three different types of flows such as parallel flow, cross flow, and two inclined flows are considered. Calculations are performed for these three typical flows in a heat exchanger changing turbulence models. The tested turbulence models are the shear stress transport (SST) model and the SSG-Reynolds stress turbulence model by Speziale, Sarkar, and Gaski (1991, “Modelling the Pressure-Strain Correlation of Turbulence: An Invariant Dynamical System Approach,” J. Fluid Mech., 227, pp. 245–272). The computational model for parallel flow is a flow past tubes inside a circular cylinder and those for the cross flow and inclined flows are flows past the perpendicular and inclined tube banks enclosed by a rectangular duct. The computational results show that the SST model produces the most reliable results that can distinguish the best heat transfer correlation from other correlations for the three different flows. It was also shown that the SSG-RSTM high-Reynolds number turbulence model does not deal with the low-Prandtl number effect properly when the Peclet number is small. According to the present calculations for a parallel flow, all the old correlations do not match with the present numerical solutions and a new correlation is proposed. The correlations by Dwyer (1966, “Recent Developments in Liquid-Metal Heat Transfer,” At. Energy Rev., 4, pp. 3–92) for a cross flow and its modified correlation that takes into account of flow inclination for inclined flows work best and are accurate enough to be used for the design of the heat exchanger.

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A comprehensive survey on utilization of hybrid nanofluid in plate heat exchanger with various number of plates

International Journal of Numerical Methods for Heat &amp Fluid Flow ◽

10.1108/hff-11-2020-0743 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Faraz Afshari ◽

Azim Doğuş Tuncer ◽

Adnan Sözen ◽

Halil Ibrahim Variyenli ◽

Ataollah Khanlari ◽

...

Keyword(s):

Heat Transfer ◽

Heat Exchanger ◽

Heat Exchangers ◽

Flow Behavior ◽

Plate Heat Exchanger ◽

Single Type ◽

Hybrid Nanofluid ◽

Content Type ◽

Plate Heat ◽

The Impact

Purpose Using suspended nanoparticles in the base fluid is known as one of the most efficient ways for heat transfer augmentation and improving the thermal efficiency of various heat exchangers. Different types of nanofluids are available and used in different applications. The main purpose of this study is to investigate the effects of using hybrid nanofluid and number of plates on the performance of plate heat exchanger. In this study, TiO2/water single nanofluid and TiO2-Al2O3/water hybrid nanofluid with 1% particle weight ratio have been used to prepare hybrid nanofluid to use in plate type heat exchangers with three various number of plates including 8, 12 and 16. Design/methodology/approach The experiments have been conducted with the aim of examining the impact of plates number and used nanofluids on heat transfer enhancement. The performance tests have been done at 40°C, 45°C, 50°C and 55°C set outlet temperatures and in five various Reynolds numbers between 1,600 and 3,800. Also, numerical simulation has been applied to verify the heat and flow behavior inside the heat exchangers. Findings The results indicated that using both nanofluids raised the thermal performance of all tested exchangers which have a various number of plates. While the major outcomes of this study showed that TiO2-Al2O3/water hybrid nanofluid has priority when compared to TiO2/water single type nanofluid. Utilization of TiO2-Al2O3/water nanofluid led to obtaining an average improvement of 7.5%, 9.6% and 12.3% in heat transfer of heat exchangers with 8, 12 and 16 plates, respectively. Originality/value In the present work, experimental and numerical analyzes have been conducted to investigate the influence of using TiO2-Al2O3/water hybrid nanofluid in various plate heat exchangers. The attained findings showed successful utilization of TiO2-Al2O3/water nanofluid. Based on the obtained results increasing the number of plates in the heat exchanger caused to obtain more increment by using both types of nanofluids.

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Performance and Exergy Transfer Analysis of Heat Exchangers with Graphene Nanofluids in Seawater Source Marine Heat Pump System

Energies ◽

10.3390/en13071762 ◽

2020 ◽

Vol 13 (7) ◽

pp. 1762 ◽

Cited By ~ 3

Author(s):

Zhe Wang ◽

Fenghui Han ◽

Yulong Ji ◽

Wenhua Li

Keyword(s):

Heat Transfer ◽

Heat Exchanger ◽

Heat Pump ◽

Heat Exchangers ◽

Transfer Model ◽

Enhanced Heat Transfer ◽

Pump System ◽

Heat Pump System ◽

Tube Heat Exchanger ◽

Exergy Transfer

A marine seawater source heat pump is based on the relatively stable temperature of seawater, and uses it as the system’s cold and heat source to provide the ship with the necessary cold and heat energy. This technology is one of the important solutions to reduce ship energy consumption. Therefore, in this paper, the heat exchanger in the CO2 heat pump system with graphene nano-fluid refrigerant is experimentally studied, and the influence of related factors on its heat transfer enhancement performance is analyzed. First, the paper describes the transformation of the heat pump system experimental bench, the preparation of six different mass concentrations (0~1 wt.%) of graphene nanofluid and its thermophysical properties. Secondly, this paper defines graphene nanofluids as beneficiary fluids, the heat exchanger gains cold fluid heat exergy increase, and the consumption of hot fluid heat is heat exergy decrease. Based on the heat transfer efficiency and exergy efficiency of the heat exchanger, an exergy transfer model was established for a seawater source of tube heat exchanger. Finally, the article carried out a test of enhanced heat transfer of heat exchangers with different concentrations of graphene nanofluid refrigerants under simulated seawater constant temperature conditions and analyzed the test results using energy and an exergy transfer model. The results show that the enhanced heat transfer effect brought by the low concentration (0~0.1 wt.%) of graphene nanofluid is greater than the effect of its viscosity on the performance and has a good exergy transfer effectiveness. When the concentration of graphene nanofluid is too high, the resistance caused by the increase in viscosity will exceed the enhanced heat transfer gain brought by the nanofluid, which results in a significant decrease in the exergy transfer effectiveness.

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The Effect of Flowrate and Effectiveness on Theoretical Design and Thermal Characteristic of a GHE

MATEC Web of Conferences ◽

10.1051/matecconf/201822501023 ◽

2018 ◽

Vol 225 ◽

pp. 01023

Author(s):

T.M. Yusof ◽

M.F. Basrawi ◽

A. Shahrani ◽

H. Ibrahim

Keyword(s):

Heat Transfer ◽

Heat Exchanger ◽

Thermal Characteristic ◽

Variable Parameter ◽

Cross Flow ◽

Outlet Temperature ◽

Performance Study ◽

Commercial Unit ◽

Hot Climate ◽

Flow Heat

Ground heat exchanger is an exciting technique to reduce energy consumption in building especially in hot climate countries. Implementation of GHE for commercial unit in Malaysia is almost none in record. Thus, performance study of the GHE in Malaysia is crucial to be conducted either experimentally or numerically. Therefore, this paper presents the performance of GHE in term of effectiveness, outlet temperature and rate of heat transfer based on mathematical model. The model is developed based on cross flow heat exchanger with one fluid unmixed. There are two variable parameter used in the analysis which is effectiveness and flowrate of the air for 25 meter length of a PVC pipe. Three effectiveness values which is 0.8, 0.9 and 0.99 have been analysed in this study. Meanwhile, flowrate of air is ranging from 0.02 to 0.2 kg/s. Results show that flowrate at 0.02 kg/s gives great temperature reduction in the pipe compared with higher flowrate. However, flowrate of 0.2 kg/s produces higher cooling potential. Characteristic of the GHE for the rate of heat transfer with 80, 90 and 99 percent effectiveness also have been developed and it has been found that effectiveness of 0.9 provide good combination between flowrate and the rate of heat transfer for 25 meter length of the pipe

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Heat transfer of hybrid nanofluid in a shell and tube heat exchanger equipped with blade-shape turbulators

Journal of Thermal Analysis and Calorimetry ◽

10.1007/s10973-020-09893-4 ◽

2020 ◽

Cited By ~ 1

Author(s):

Aysan Shahsavar Goldanlou ◽

Mohammad Sepehrirad ◽

Mostafa Papi ◽

Ahmed Kadhim Hussein ◽

Masoud Afrand ◽

...

Keyword(s):

Heat Transfer ◽

Heat Exchanger ◽

Hybrid Nanofluid ◽

Tube Heat Exchanger ◽

Blade Shape ◽

Shell And Tube

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Cross flow and heat transfer past a permeable stretching/shrinking sheet in a hybrid nanofluid

International Journal of Numerical Methods for Heat &amp Fluid Flow ◽

10.1108/hff-05-2020-0298 ◽

2020 ◽

Vol ahead-of-print (ahead-of-print) ◽

Cited By ~ 1

Author(s):

Natalia C. Roşca ◽

Alin V. Roşca ◽

Amin Jafarimoghaddam ◽

Ioan Pop

Keyword(s):

Heat Transfer ◽

Differential Equations ◽

Cross Flow ◽

Porous Wall ◽

Shrinking Sheet ◽

Hybrid Nanofluid ◽

Lower Branch ◽

Content Type ◽

Flow And Heat Transfer ◽

Branch Solution

Purpose The purpose of this paper is to study the laminar boundary layer cross flow and heat transfer on a rotational stagnation-point flow over either a stretching or shrinking porous wall submerged in hybrid nanofluids. The involved boundary layers are of stream-wise type with stretching/shrinking process along the surface. Design/methodology/approach Using appropriate similarity variables the partial differential equations are reduced to ordinary (similarity) differential equations. The reduced system of equations is solved analytically (by high-order perturbed field propagation for small to moderate stretching/shrinking parameter and low-order perturbation for large stretching/shrinking parameter) and numerically using the function bvp4c from MATLAB for different values of the governing parameters. Findings It was found that the basic similarity equations admit dual (upper and lower branch) solutions for both stretching/shrinking surfaces. Moreover, performing a linear stability analysis, it was confirmed that the upper branch solution is realistic (physically realizable), while the lower branch solution is not physically realizable in practice. These dual solutions will be studied in the present paper. Originality/value The authors believe that all numerical results are new and original and have not been published before for the present problem.

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