scholarly journals The dependence of heat transfer and friction on fin tip configuration

1987 ◽  
Vol 6 (3) ◽  
pp. 130-135
Author(s):  
L. J. C. Steyn ◽  
L. Pretorius ◽  
J. Visser
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Theoretical Model ◽  
Experimental Tests ◽  
Experimental Results ◽  
Tube Heat Exchanger ◽  
Friction Parameters ◽  
Annular Fins

The dependence of heat transfer and friction parameters on fin tip configuration is investigated. Experimental tests are performed on a double tube heat exchanger with transverse annular fins on the inner tube. Seven different fin configurations are investigated. A theoretical model is used to calculate the heat transfer and friction parameters from experimental results.

scholarly journals Experimental Research and Simulation of Fin and Tube Heat Exchanger

2017 ◽  
Vol 9 (4) ◽  
pp. 451-461
Author(s):  
Artur Rubcov ◽  
Sabina Paulauskaitė ◽  
Violeta Misevičiūtė
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Transfer Coefficient ◽  
Heat Exchangers ◽  
Ventilation System ◽  
Experimental Tests ◽  
Maximum Heat ◽  
Tube Heat Exchanger ◽  
The Heat Transfer Coefficient

The paper provides the results of experimental and theoretical test of a wavy fin and tube heat exchanger used to cool air in a ventilation system when the wavy fin of the heat exchanger is dry and wet. The experimental tests, performed in the range of 1000<Re<4500 of the Reynolds number applying LMTD-LMED methodology, determined the dependency of the heat transfer coefficient on the supplied air flow rate with the varying geometry of the heat exchanger (the number of tube rows, the distance between fins, the thickness of the fin and the diameter of the tube). The experimental tests were performed on 9 heat exchangers in heating and 6 heat exchangers in cooling mode. After processing the results of the experimental tests, empirical equation defining the characteristics of the heat transfer coefficient of all heat exchangers were derived. The maximum heat transfer coefficient deviation is 11.6 percent. The correction factor of the wet fin (Lewis number) depending on the number of Reynolds, which ranges from 0.75 to 1.1 also is determined. Maximum capacity deviation equals 3.7 percent. The obtained equations can only be applied to a certain group of heat exchangers (with the same shape of fins or the distance between the tubes). The results of the experimental test and simulation with ANSYS program are compared and the heat transfer coefficients vary from 6.5 to 11.4 percent.

scholarly journals Design and Simulation of Counter Flow Heat Exchanger with Fins and Internal Ribs

2021 ◽  
Vol 9 (VI) ◽  
pp. 3221-3227
Author(s):  
Dr. Asheesh Kumar
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Transfer Process ◽  
Primary Objective ◽  
Experimental Results ◽  
Tube Heat Exchanger ◽  
Higher Temperature ◽  
Solid Works ◽  
Lower Temperature ◽  
Temperature Water

A Heat Exchanger is a device to transfer heat from fluid at higher temperature to fluid at lower temperature with highest efficiency. Designed for various applications such as preheating the water before sending it into boiler for generation of steam. This work is carried out with the primary objective of increasing the thermal efficiency of the procedure heat transfer process. There are different types of heat exchangers from which shell and tube heat exchanger is considered for this present work. High temperature water passes through the copper tubes and low temperature water flows outside the copper tubes. To enhance the rate of heat, transfer the modified design is implemented. The design consists of fins outside the copper tubes to increase the surface area in contact with outside fluid. Also, ribs are provided inside the copper tubes for increasing the turbulence along with more area of contact. This paper mainly deals with design, modelling and CFD analysis of the heat exchanger. Overall heat transfer coefficient of the fins and internal ribs of heat exchanger is based on the results of effectiveness-NTU approach and LMTD approach. Modelling of various components are presented with the help of standard modelling software, solid works. Simulation of the process is done using ANSYS. The simulated results obtained in the software are compared with the published experimental results which are very close to our modified design heat exchanger and it is found that the results are very close to experimental results.

Experimental Analysis of Fin and Tube Heat Exchanger in Heating and Cooling Mode

2017 ◽  
Author(s):  
Artur Rubcov ◽  
Sabina Paulauskaitė ◽  
Violeta Misevičiūtė
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Transfer Coefficient ◽  
Heat Exchangers ◽  
Ventilation System ◽  
Experimental Tests ◽  
Cooling Mode ◽  
Tube Heat Exchanger ◽  
The Heat Transfer Coefficient

The paper provides the results of experimental tests of a wavy fin and tube heat exchanger used to heat (cool) air in a ventilation system when the wavy fin of the heat exchanger is dry and wet. The experimental tests, performed in the range of 1000<Re<4500 of the Reynolds number, determined the dependency of the heat transfer coefficient on the amount of supplied air with the varying geometry of the heat exchanger (the number of tube rows, the distance between fins, the thickness of the fin and the diameter of the tube). The experimental tests were performed on 9 heat exchangers in heating mode (dry fin) and 6 heat exchangers in cooling mode (wet fin). The ratio of heat transfer coefficient values when the fin is dry and wet varies from 0.79 to 1.12. After processing the results of the experimental tests, equations defining the dependency of the heat transfer coefficient on the amount of air and varying geometric parameters of the heat exchanger were derived, based on which 86% to 88% of the results do not exceed the 10% tolerance margin and the standard deviation varies from 3.5% to 4.3%.

scholarly journals Numerical Analysis of Tube Heat Exchanger with Perforated Star-Shaped Fins

Fluids ◽  
2020 ◽  
Vol 5 (4) ◽  
pp. 242
Author(s):  
Mladen Bošnjaković ◽  
Simon Muhič
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Numerical Analysis ◽  
Heat Transfer Performance ◽  
Transfer Performance ◽  
Tube Heat Exchanger ◽  
Computational Fluid Dynamics Cfd ◽  
Annular Fins ◽  
Good Heat ◽  
Cfd Numerical Analysis

This article discusses the possibility of further reducing the mass of the heat exchanger with stainless steel star-shaped fins while achieving good heat transfer performance. For this purpose, we perforated the fins with holes Ø2, Ø3, and Ø4 mm. Applying computational fluid dynamics (CFD) numerical analysis, we determined the influence of each perforation on the characteristics of the flow field in the liquid–gas type of heat exchanger and the heat transfer for the range of Re numbers from 2300 to 16,000. With a reduction in the mass of the fins to 17.65% (by Ø4 mm), perforated fins had greater heat transfer from 5.5% to 11.3% than fins without perforation. A comparison of perforated star-shaped fins with annular fins was also performed. Perforated fins had 51.8% less mass than annular fins, with an increase in heat transfer up to 26.5% in terms of Nusselt number.

Experimental Investigation of Heat Transfer Enhancement by Using Different Number of Fins in Circular Tube

2018 ◽  
Vol 6 (3) ◽  
pp. 1-12
Author(s):  
Kamil Abdul Hussien
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Cold Water ◽  
Finned Tube ◽  
Hot Water ◽  
Copper Tube ◽  
Smooth Tube ◽  
Tube Heat Exchanger ◽  
Mass Flow Rates ◽  
Flow Heat

Abstract-The present work investigates the enhancement of heat transfer by using different number of circular fins (8, 10, 12, 16, and 20) in double tube counter flow heat exchanger experimentally. The fins are made of copper with dimensions 66 mm OD, 22 mm ID and 1 mm thickness. Each fin has three of 14 mm diameter perforations located at 120o from each to another. The fins are fixed on a straight smooth copper tube of 1 m length, 19.9 mm ID and 22.2 mm OD. The tube is inserted inside the insulated PVC tube of 100 mm ID. The cold water is pumped around the finned copper tube, inside the PVC, at mass flow rates range (0.01019 - 0.0219) kg/s. The Reynold's number of hot water ranges (640 - 1921). The experiment results are obtained using six double tube heat exchanger (1 smooth tube and the other 5 are finned one). The results, illustrated that the heat transfer coefficient proportionally with the number of fin. The results also showed that the enhancement ratio of heat transfer for finned tube is higher than for smooth tube with (9.2, 10.2, 11.1, 12.1 13.1) times for number of fins (8, 10, 12, 16 and 20) respectively.

Numerical simulation of the effect of baffle cut and baffle spacing on shell side heat exchanger performance using CFD

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Swanand Gaikwad ◽  
Ashish Parmar
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Numerical Results ◽  
Shell Side ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
Two Parameters

AbstractHeat exchangers possess a significant role in energy transmission and energy generation in most industries. In this work, a three-dimensional simulation has been carried out of a shell and tube heat exchanger (STHX) consisting of segmental baffles. The investigation involves using the commercial code of ANSYS CFX, which incorporates the modeling, meshing, and usage of the Finite Element Method to yield numerical results. Much work is available in the literature regarding the effect of baffle cut and baffle spacing as two different entities, but some uncertainty pertains when we discuss the combination of these two parameters. This study aims to find an appropriate mix of baffle cut and baffle spacing for the efficient functioning of a shell and tube heat exchanger. Two parameters are tested: the baffle cuts at 30, 35, 40% of the shell-inside diameter, and the baffle spacing’s to fit 6,8,10 baffles within the heat exchanger. The numerical results showed the role of the studied parameters on the shell side heat transfer coefficient and the pressure drop in the shell and tube heat exchanger. The investigation shows an increase in the shell side heat transfer coefficient of 13.13% when going from 6 to 8 baffle configuration and a 23.10% acclivity for the change of six baffles to 10, for a specific baffle cut. Evidence also shows a rise in the pressure drop with an increase in the baffle spacing from the ranges of 44–46.79%, which can be controlled by managing the baffle cut provided.

scholarly journals Characterization of heat transfer on concentric tube heat exchanger using ethylene glycol/TiO2 nanofluid

2021 ◽  
Vol 1034 (1) ◽  
pp. 012045
Author(s):  
Herry Irawansyah ◽  
Abdul Ghofur ◽  
Rachmat Subagyo ◽  
Mastiadi Tamjidillah ◽  
Bagus Harits Pratama ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Ethylene Glycol ◽  
Tube Heat Exchanger

scholarly journals Experimental analysis and ANN prediction on performances of finned oval-tube heat exchanger under different air inlet angles with limited experimental data

Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 968-980
Author(s):  
Xueping Du ◽  
Zhijie Chen ◽  
Qi Meng ◽  
Yang Song
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Heat Exchanger ◽  
Correlation Equation ◽  
Tube Heat Exchanger ◽  
Flow Friction ◽  
Air Inlet ◽  
Comparison Results ◽  
Wide Range ◽  
Oval Tube

Abstract A high accuracy of experimental correlations on the heat transfer and flow friction is always expected to calculate the unknown cases according to the limited experimental data from a heat exchanger experiment. However, certain errors will occur during the data processing by the traditional methods to obtain the experimental correlations for the heat transfer and friction. A dimensionless experimental correlation equation including angles is proposed to make the correlation have a wide range of applicability. Then, the artificial neural networks (ANNs) are used to predict the heat transfer and flow friction performances of a finned oval-tube heat exchanger under four different air inlet angles with limited experimental data. The comparison results of ANN prediction with experimental correlations show that the errors from the ANN prediction are smaller than those from the classical correlations. The data of the four air inlet angles fitted separately have higher precisions than those fitted together. It is demonstrated that the ANN approach is more useful than experimental correlations to predict the heat transfer and flow resistance characteristics for unknown cases of heat exchangers. The results can provide theoretical support for the application of the ANN used in the finned oval-tube heat exchanger performance prediction.

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