Heat Transfer Through Metal-Foam Heat Exchanger at Higher Temperature

2013 ◽  
Author(s):  
P. Hafeez ◽  
J. Esmaeelpanah ◽  
S. Chandra ◽  
J. Mostaghimi
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Surface Temperature ◽  
Heat Exchangers ◽  
Metal Foam ◽  
Spray Deposition ◽  
Nickel Foam ◽  
High Strength ◽  
Heating System ◽  
Higher Temperature

Open pore metal foams are lightweight and offer high strength, rigidity, and a large heat transfer area per volume. They make efficient heat exchangers because of high thermal conductivity and high permeability. These heat exchangers made of nickel foam are suitable for high temperature application. They can be manufactured by shaping the foam into any desired configuration and depositing metal skins on it using thermal spray deposition method. Combustion based heating system that burns natural gas is designed to understand the heat transfer through metal foam heat exchanger at higher temperature. A test rig has been fabricated to perform heat transfer experiments. The rig is capable of generating hot combustion gases through methane-oxygen premixed combustion chamber. The design of the rig allows exposure of the thermally sprayed nickel foam to hot gases and finally, cooling the metal foam by circulating air through it. The experiments were performed on metal foam and hollow channel to measure the heat transfer enhancement of the metal foam. The surface temperature measurements were done for different flow rates of cooling air. A significant decrease in surface temperature of metal foam was observed.

Spray-Formed, Metal-Foam Heat Exchangers for High Temperature Applications

2009 ◽  
Vol 1 (3) ◽  
Author(s):  
H. R. Salimi Jazi ◽  
J. Mostaghimi ◽  
S. Chandra ◽  
L. Pershin ◽  
T. Coyle
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Prolonged Exposure ◽  
Metal Foam ◽  
Nickel Foam ◽  
Inconel 625 ◽  
Arc Spraying ◽  
Transfer Coefficients ◽  
High Heat Transfer

Open pore metal foams make efficient heat exchanger because of their high thermal conductivity and low permeability. This study describes a novel method of using wire-arc spraying to deposit Inconel 625 skins on the surface of sheets of 10 and 20 pores per linear inch nickel foam. The skins adhere strongly to the foam struts, giving high heat-transfer rates. Tests were done to determine the hydraulic and thermal characteristics of the heat exchangers and correlations developed to calculate Fanning friction factor and Nusselt number as a function of Reynolds number for airflow through the foam. Measured heat-transfer coefficients for the foam heat exchangers are greater than those of straight flow channels at the same flow rate. A ceramic thermal barrier coating was deposited on one face of the heat exchanger using plasma spraying. The coating and heat exchanger survived prolonged exposure to the flame of a methane-air burner.

scholarly journals Effects of Heat Transfer Analysis Through Boson Femtoscopy with Fraction Order Differentiation

2021 ◽  
Author(s):  
Ghulam Bary ◽  
Waqar Ahmed ◽  
Muhammad Sajid ◽  
Riaz Ahmad ◽  
Ilyas Khan
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Difference Equations ◽  
Correlation Functions ◽  
Heat Exchangers ◽  
Particle Production ◽  
Heat Transfer Analysis ◽  
Significant Difference ◽  
Higher Temperature

Higher order femtoscopy measured to examine the heat exchanger characterization of the fluid debris produced in the collisions and investigated a remarkable suppression in the bosons interferences measurement. The analogous suppression can be analyzed to explore the coherence of boson thermal particle production sources at unprecedented energies. We illustrate the particles emissions from radiated sources with statistical coherence which induce the thermal particles interferences to probe the peculiarity of the heated sources as well as the distinctions about the heat exchangers in the collisions at higher temperature. We perspicacious that the bosons seem to the pertinent aspirant of heat exchanger, and the normalized three particles correlators evaluate the existence of such hybrid phases significantly. The key point of this research is that we analyze the three particles correlations with their normalized correlations by difference equations to determine the characteristics of heat exchanger and its applications. With such distinctive and efficient approach, we observe a significant difference in the correlation functions at higher temperature and momenta regimes.

The Impact of Base Metal on the Thermal-Hydraulic Performance of Metal Foam Heat Exchanger for Cooling and Dehumidification Applications

2017 ◽  
Author(s):  
Kashif Nawaz ◽  
Anthony M. Jacobi
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Exchanger ◽  
Base Metal ◽  
Heat Exchangers ◽  
Transfer Rate ◽  
Metal Foam ◽  
Operating Conditions ◽  
Copper Metal ◽  
The Impact

In the wake of utilization of novel materials in various thermal applications open cell metal foams have received attention due to their inherent properties such as large surface area to volume ratio and higher thermal conductivity. Additionally, complex tetradecahedron structure promotes mixing and makes them a good candidate for heat transfer applications. In this paper, a relative comparison has been made between the thermal-hydraulic performance of aluminum and copper metal foam heat exchangers with the same geometry under dry and wet operating conditions. Heat exchanger consisting of round tube with annular layer of metal foam have been considered. Experiments have been conducted using a closed-loop wind tunnel to measure the heat transfer performance and pressure drop. The impact of base metal (aluminum and copper) on the heat transfer rate has been evaluated at varying air flow rates and upstream relative humidity. It has been found that due to similar geometry (flow depth, face area, pore size) both aluminum and copper foam samples have comparable pressure drop under dry conditions. However, the pressure gradient was noticeably different for two samples under wet operating conditions. An obvious difference in heat transfer rate for aluminum and copper metal foam heat exchangers was observed under both dry and wet operating conditions. The findings have been explained in terms of the impact of the thermal conductivity of base metal and condensate retention.

Optimal distribution of metal foam inserts in a double-pipe heat exchanger

2019 ◽  
Vol 29 (4) ◽  
pp. 1322-3142 ◽  
Author(s):  
Hossein Arasteh ◽  
Mohammad Reza Salimpour ◽  
Mohammad Reza Tavakoli
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Transfer Rate ◽  
Heat Exchangers ◽  
Transfer Rate ◽  
Metal Foam ◽  
Metal Foams ◽  
Content Type ◽  
Overall Heat Transfer Coefficient ◽  
Double Pipe

PurposeIn the present research, a numerical investigation is carried out to study the fluid flow and heat transfer in a double-pipe, counter-flow heat exchanger exploiting metal foam inserts partially in both pipes. The purpose of this study is to achieve the optimal distribution of a fixed volume of metal foam throughout the pipes which provides the maximum heat transfer rate with the minimum pressure drop increase.Design/methodology/approachThe governing equations are solved using the finite volume method. The metal foams are divided into different number of parts and positioned at different locations. The number of metal foam parts, their placements and their volume ratios in each pipe are sought to reach the optimal conditions. The four-piece metal foam with optimized placement and partitioning volume ratios is selected as the best layout. The effects of the permeability of metal foam on the Nusselt number, the performance evaluation criteria (PEC) and the overall heat transfer coefficient are investigated.FindingsIt was observed that the heat transfer rate, the overall heat transfer coefficient and the effectiveness of the heat exchanger can be improved as high as 69, 124 and 9 per cent, respectively, while the highest value of PEC is 1.36.Practical implicationsPorous materials are widely used in thermo-fluid systems such as regenerators, heat sinks, solar collectors and heat exchangers.Originality/valueHaving less pressure drop than fully filled heat exchangers, partially filled heat exchangers with partitioned metal foams distributed optimally enhance heat transfer rate more economically.

Influence of Covering Layer on Surface Temperature of Floor Radiant Heating System

2012 ◽  
Vol 204-208 ◽  
pp. 4260-4263 ◽  
Author(s):  
Hai Qian Zhao ◽  
Zhong Hua Wang ◽  
Lan Shuang Zhang
Keyword(s):  
Heat Transfer ◽  
Surface Temperature ◽  
Heating System ◽  
Radiant Heating ◽  
Wooden Floor ◽  
Surface Temperature Distribution ◽  
Covering Layer ◽  
Floor Surface ◽  
Space Saving ◽  
Cover Material

Floor radiant heating system has many advantages, energy and space saving, for example. The radiant floor is the radiator of floor radiant heating system, and its thermal parameters influence surface temperature distribution and comfort. In this paper, mathematical model of heat exchange coil under floor was established, and boundary heat transfer conditions were given. Based on these, surface temperature of different covering layer was calculated. According to the results, using different covering layer, the floor surface temperature has a great difference. Using wooden floor as cover material, the floor surface temperature is more moderate and uniform.

Development of Heat Exchanger Fouling Model and Preventive Maintenance Diagnostic Tool

2007 ◽  
Vol 2 (2) ◽  
Author(s):  
H. Zabiri ◽  
V. R. Radhakrishnan ◽  
M. Ramasamy ◽  
N. M. Ramli ◽  
V. Do Thanh ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Predictive Model ◽  
Diagnostic Tool ◽  
Preventive Maintenance ◽  
Heat Exchangers ◽  
Waste Heat ◽  
A Priori ◽  
Transfer Efficiency ◽  
Heat Transfer Efficiency

The Crude Preheat Train (CPT) is a set of large heat exchangers which recover the waste heat from product streams back to preheat the crude oil. The overall heat transfer coefficient in these heat exchangers may be significantly reduced due to fouling. One of the major impacts of fouling in CPT operation is the reduced heat transfer efficiency. The objective of this paper is to develop a predictive model using statistical methods which can a priori predict the rate of the fouling and the decrease in heat transfer efficiency in a heat exchanger in a crude preheat train. This predictive model will then be integrated into a preventive maintenance diagnostic tool to plan the cleaning of the heat exchanger to remove the fouling and bring back the heat exchanger efficiency to their peak values. The fouling model was developed using historical plant operating data and is based on Neural Network. Results show that the predictive model is able to predict the shell and tube outlet temperatures with excellent accuracy, where the Root Mean Square Error (RMSE) obtained is less than 1%, correlation coefficient R2 of approximately 0.98 and Correct Directional Change (CDC) values of more than 90%. A preliminary case study shows promising indication that the predictive model may be integrated into a preventive maintenance scheduling for the heat exchanger cleaning.

Heat Transfer Performance of Different Nanofluids Flows in a Helically Coiled Heat Exchanger

2013 ◽  
Vol 832 ◽  
pp. 160-165 ◽  
Author(s):  
Mohammad Alam Khairul ◽  
Rahman Saidur ◽  
Altab Hossain ◽  
Mohammad Abdul Alim ◽  
Islam Mohammed Mahbubul
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Friction Factor ◽  
Heat Exchangers ◽  
Heat Transfer Performance ◽  
Volume Concentration ◽  
Transfer Performance

Helically coiled heat exchangers are globally used in various industrial applications for their high heat transfer performance and compact size. Nanofluids can provide excellent thermal performance of this type of heat exchangers. In the present study, the effect of different nanofluids on the heat transfer performance in a helically coiled heat exchanger is examined. Four different types of nanofluids CuO/water, Al2O3/water, SiO2/water, and ZnO/water with volume fractions 1 vol.% to 4 vol.% was used throughout this analysis and volume flow rate was remained constant at 3 LPM. Results show that the heat transfer coefficient is high for higher particle volume concentration of CuO/water, Al2O3/water and ZnO/water nanofluids, while the values of the friction factor and pressure drop significantly increase with the increase of nanoparticle volume concentration. On the contrary, low heat transfer coefficient was found in higher concentration of SiO2/water nanofluids. The highest enhancement of heat transfer coefficient and lowest friction factor occurred for CuO/water nanofluids among the four nanofluids. However, highest friction factor and lowest heat transfer coefficient were found for SiO2/water nanofluids. The results reveal that, CuO/water nanofluids indicate significant heat transfer performance for helically coiled heat exchanger systems though this nanofluids exhibits higher pressure drop.

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.

scholarly journals Performance analyses of helical coil heat exchangers. The effect of external coil surface modification on heat exchanger effectiveness

2016 ◽  
Vol 37 (4) ◽  
pp. 137-159 ◽  
Author(s):  
Rafał Andrzejczyk ◽  
Tomasz Muszyński
Keyword(s):  
Heat Transfer ◽  
Surface Modification ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Helical Structure ◽  
Nuclear Industry ◽  
Helical Coil ◽  
Tube Heat Exchanger ◽  
High Heat Transfer ◽  
Coil Heat

Abstract The shell and coil heat exchangers are commonly used in heating, ventilation, nuclear industry, process plant, heat recovery and air conditioning systems. This type of recuperators benefits from simple construction, the low value of pressure drops and high heat transfer. In helical coil, centrifugal force is acting on the moving fluid due to the curvature of the tube results in the development. It has been long recognized that the heat transfer in the helical tube is much better than in the straight ones because of the occurrence of secondary flow in planes normal to the main flow inside the helical structure. Helical tubes show good performance in heat transfer enhancement, while the uniform curvature of spiral structure is inconvenient in pipe installation in heat exchangers. Authors have presented their own construction of shell and tube heat exchanger with intensified heat transfer. The purpose of this article is to assess the influence of the surface modification over the performance coefficient and effectiveness. The experiments have been performed for the steady-state heat transfer. Experimental data points were gathered for both laminar and turbulent flow, both for co current- and countercurrent flow arrangement. To find optimal heat transfer intensification on the shell-side authors applied the number of transfer units analysis.

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