Plate-Fin Surface Optimisation Using Direct-Sizing

2000 ◽  
Author(s):  
Eric M. Smith
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Design Procedure ◽  
Local Geometry ◽  
Flow Friction ◽  
The Core ◽  
Plate Spacing ◽  
Offset Strip Fin ◽  
Strip Length

Abstract The direct-sizing of heat exchangers applies to that class of heat exchanger in which the local geometry of the core is the same everywhere. Many of our best performing exchangers possess this property. Previous papers discussing this topic were published by Smith (1994, 1997a). Optimisation of rectangular offset strip-fin (ROSF) surfaces involves varying plate spacing b, cell pitch c, and strip-length x in a logical manner. The Manglik and Bergles correlations for flow-friction and heat transfer of ROSF surfaces permits such optimisation. The design procedure which follows applies to a two-stream contraflow exchanger assuming perfect gases.

Experimental and Numerical Analyses of Friction Factors in Offset Strip Fin Heat Exchangers

2007 ◽  
Author(s):  
Aihua Wang ◽  
Samir F. Moujaes ◽  
Yitung Chen ◽  
Valery Ponyavin
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Heat Exchanger ◽  
Friction Factor ◽  
Heat Exchangers ◽  
Experimental Measurements ◽  
Test Rig ◽  
Compact Heat Exchangers ◽  
Friction Factors ◽  
Offset Strip Fin

Heat transfer in compact heat exchangers is augmented by the introduction of the offset strip fins. With the breakdown of the thermal and hydro boundary layers to boost heat transfer, the fins increase the friction power. Two heat exchangers of different fin geometries structures were built and tested. The results of the study show that the round-edge-fin heat exchanger has the smaller friction factor. A test rig was constructed to measure the friction factor of the offset strip fin heat exchangers with air. A modified hydraulic diameter was used to calculate the main parameters. The computational fluid dynamics package FLUENT was used to predict the flow in the heat exchanger. The numerical investigation was conducted and compared with experimental measurements.

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.

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.

The Single-Blow Transient Testing Technique for Compact Heat Exchanger Surfaces

1967 ◽  
Vol 89 (1) ◽  
pp. 29-38 ◽  
Author(s):  
P. F. Pucci ◽  
C. P. Howard ◽  
C. H. Piersall
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Transfer Performance ◽  
Compact Heat Exchanger ◽  
Experimental Facility ◽  
Nickel Plate ◽  
Heat Transfer Characteristics ◽  
Power Penalty ◽  
Testing Technique ◽  
Flow Friction

The single-blow, transient testing technique for determining the heat transfer characteristics of heat exchanger surfaces, with a summary of the underlying theory, a description of an experimental facility, and comments on the applicability of the technique, are presented. Heat transfer and flow friction data are presented for plate-fin type surfaces fabricated of perforated nickel plate. The data indicate that perforations increase heat transfer performance without a large frictional power penalty.

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.

Thermo-Mechanical Design of Brazed Plate-Fins Heat Exchanger Based on Finite Element Modeling Using Homogenization Techniques

2009 ◽  
Author(s):  
Johan Dib ◽  
Ivan Lewon ◽  
Boris Martin
Keyword(s):  
Finite Element ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Mechanical Design ◽  
Periodic Structures ◽  
Software Tool ◽  
Design Criteria ◽  
Base Metals ◽  
The Core ◽  
Aluminum Base

Using classical Finite Element (FE) tools to model heat exchangers emphasizes the need to elaborate specific methods to reduce the size of the numerical problem. Among these methods, homogenization techniques can be adapted and used for Brazed Aluminum Plate-Fins Heat Exchangers (BAHX) including layers of periodic structures. Actually the core is formed by stacking single layers consisting of periodic corrugated fins, side-bar and parting sheets which are all made of aluminum base metals, and brazed in a furnace. So in this paper a global methodology of BAHX modeling and design is presented. It integrates homogenization techniques to perform FE calculation and localization techniques to allow applying the appropriate design criteria. Finally, to validate this methodology, results are then compared on a basic heat exchanger modeled both by classical FE tools and a dedicated software tool encapsulating both homogenization and localization techniques.

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.

scholarly journals Execution of a Smart Prediction Tool to Evaluate Thermal Performance in a heat exchanger by using Single Elliptical Leaf Strips with altered Angle

2019 ◽  
Vol 8 (11) ◽  
pp. 123-131
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Thermal Performance ◽  
Heat Exchangers ◽  
Industrial Applications ◽  
Generalized Regression Neural Network ◽  
Prediction Tool ◽  
Pressure Drops ◽  
Transfer Rates ◽  
Mass Flow Rates

Heat exchangers are prominent industrial applications where engineering science of heat transfer and Mass transfer occurs. It is a contrivance where transfer of energy occurs to get output in the form of energy transfer. This paper aims at finding a solution to improve the thermal performance in a heat exchanger by using passive method techniques. This experimental and numerical analysis deals with finding the temperature outlets of cold and hot fluid for different mass flow rates and also pressure drop in the tube and the annular side by adding an elliptical leaf strip in the pipe at various angles. The single elliptical leaf used in experiment has major to minor axes ratios as 2:1 and distance of 50 mm between two leaves are arranged at different angular orientations from 0 0 to 1800 with 100 intervals. Since it’s not possible to find the heat transfer rates and pressure drops at every orientation of elliptical leaf so a generalized regression neural network (GRNN) prediction tool is used to get outputs with given inputs to avoid experimentation. GRNN is a statistical method of determining the relationship between dependent and independent variables. The values obtained from experimentation and GRNN nearly had precise values to each other. This analysis is a small step in regard with encomiastic approach for enhancement in performance of heat exchangers

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