Comparison Between Numerical and Experimental Gas Side Heat Transfer and Pressure Drop of a Tube Bank With Solid and Segmented Circular I-Fins

2012 ◽  
Author(s):  
Rene Hofmann ◽  
Heimo Walter
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Tube Bundle ◽  
Three Dimensional ◽  
Finned Tube ◽  
Three Dimensional Model ◽  
Finned Tubes ◽  
Numerical Predictions ◽  
Staggered Arrangement ◽  
Flow Experiments

In the present work, a comparison between numerical and experimental gas side heat transfer and pressure drop for a tube bundle with solid and segmented circular finned tubes in a staggered arrangement is investigated. For the numerical simulations a three dimensional model of the finned tube are applied. Renormalization group theory (RNG) based k–ε turbulence model was used to calculate the turbulent flow. Experiments have been carried out to validate the numerical predictions. The numerical results for the Nu-number and pressure drop coefficient show a good agreement with the data from measurement. A comparison between solid and segmented finned tubes from the global calculation of the Nu-numbers within the analyzed Re-range shows an enhancement by applying segmented finned tubes rather than finned tubes with solid fins.

Film Condensation of R-113 on In-Line Bundles of Horizontal Finned Tubes

1991 ◽  
Vol 113 (2) ◽  
pp. 479-486 ◽  
Author(s):  
H. Honda ◽  
B. Uchima ◽  
S. Nozu ◽  
H. Nakata ◽  
E. Torigoe
Keyword(s):  
Heat Transfer ◽  
Tube Bundle ◽  
Three Dimensional ◽  
Finned Tube ◽  
Film Condensation ◽  
Line Bundles ◽  
Finned Tubes ◽  
Fin Tube ◽  
Fin Tubes ◽  
Annular Fins

Film condensation of R-113 on in-line bundles of horizontal finned tubes with vertical vapor downflow was experimentally investigated. Two tubes with flat-sided annular fins and four tubes with three-dimensional fins were tested. The test sections were 3×15 tube bundles with and without two rows of inundation tubes at the top. Heat transfer measurements were carried out on a row-by-row basis. The heat transfer enhancement due to vapor shear was much less for a finned tube bundle than for a smooth tube bundle. The decrease in heat transfer due to condensate inundation was more marked for a three-dimensional fin tube than for a flat-sided fin tube. The predictions of the previous theoretical model for a bundle of flat-sided fin tubes agreed well with the measured data for low vapor velocity and a small to medium condensate inundation rate. Among the six tubes tested, the highest heat transfer performance was provided by the flat-sided fin tube with fin dimensions close to the theoretically determined optimum values.

Experimental and Numerical Investigation of the Gas Side Heat Transfer and Pressure Drop of Finned Tubes—Part II: Numerical Analysis

2012 ◽  
Vol 4 (4) ◽  
Author(s):  
Rene Hofmann ◽  
Heimo Walter
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Numerical Study ◽  
Three Dimensional ◽  
Finned Tube ◽  
Renormalization Group Theory ◽  
Tube Material ◽  
Finned Tubes ◽  
Steady State Temperature ◽  
Volume Method

The heat transfer and pressure drop behavior of segmented circular and helical as well as solid finned tubes are investigated in a three-dimensional numerical study. The simulation is carried out using a finite volume method for calculating the steady-state temperature and flow field of the fluid as well as the temperature distribution of the tube material. For modeling the turbulence, the k-ε turbulence model based on the renormalization group theory (RNG) is used to resolve the near-wall treatment between adjacent fins. All simulations are performed in the Re range between 3500 ≤ Re ≤ 50,000. The influence of Reynolds number and fin geometry (segmented or solid and circular or helical) on the local and global averaged heat transfer and pressure drop was studied. A comparison between solid and segmented finned tube has shown that the heat transfer and pressure drop for the segmented finned tubes is higher. The numerical results are compared with experimental data.

Tube Banks Heat Transfer Enhancement Using Conical Fins

2010 ◽  
Author(s):  
Ignacio Carvajal-Mariscal ◽  
Florencio Sanchez-Silva ◽  
Georgiy Polupan
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Pressure Drop ◽  
Finned Tube ◽  
Hot Water ◽  
Experimental Results ◽  
Tube Bank ◽  
Finned Tubes ◽  
Tube Banks ◽  
Annular Fins

In this work the heat transfer and pressure drop experimental results obtained in a two step finned tube bank with conical fins are presented. The tube bank had an equilateral triangle array composed of nine finned tubes with conical fins inclined 45 degrees in respect with the tube axis. The heat exchange external area of a single tube is approximately 0.07 m2. All necessary thermal parameters, inlet/outlet temperatures, mass flows, for the heat balance in the tube bank were determined for different air velocities, Re = 3400–18400, and one constant thermal charge provided by a hot water flow with a temperature of 80 °C. As a result, the correlations for the heat transfer and pressure drop calculation were obtained. The experimental results were compared against the analytical results for a tube bank with annular fins with the same heat exchange area. It was found that the proposed tube bank using finned tubes with conical fins shows an increment of heat transfer up to 58%.

Experimental and Numerical Investigation of the Gas Side Heat Transfer and Pressure Drop of Finned Tubes—Part I: Experimental Analysis

2012 ◽  
Vol 4 (4) ◽  
Author(s):  
Rene Hofmann ◽  
Heimo Walter
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Flow Direction ◽  
Measurement Data ◽  
Heat Transfer Correlation ◽  
Average Deviation ◽  
Finned Tubes ◽  
Measurement Results ◽  
Staggered Arrangement ◽  
Industrial Boiler

In this study, a heat transfer and pressure drop correlation are determined for helically I- and U-shaped finned tubes as well as for solid I-finned tubes at constant transverse and longitudinal spacing. In the heat transfer correlation, the influence of the number of tube rows arranged in flow direction is taken into consideration. A detailed description of the test rig and the data reduction procedure is presented. A thorough uncertainty analysis was performed to validate the results. The investigation has shown that the influence of the fin geometry on the heat transfer of the helically segmented I- and U-shaped tubes can be disregarded. The heat transfer correlation, which is valid for the helically segmented I- and U-shaped tubes in a staggered arrangement, can describe 90% of all measurement data within ±15%. All measurements are performed for constant transverse and longitudinal spacing. For the pressure drop coefficient, two new correlations, which are only valid for helically segmented U shaped finned tubes in a staggered arrangement, show an average deviation of approximately ±13% for 90% of all measurement results. All new correlations are compared with correlations from open and established literature for industrial boiler applications. The new heat transfer and pressure drop correlations show a relative deviation of ±20% in comparison with correlations in open literature. The new pressure drop correlations show the same characteristic as most correlations in the open literature.

An Investigation of Heat Transfer and Pressure Drop Enhancement of Various Perforated Circular Finned Tubes at Different Tube Tilt Angles

2021 ◽  
pp. 10295-10338
Author(s):  
Yahya Yaser Shanyour AL-Salman, Ali Sabri Abbas
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Heat Transfer Rate ◽  
Tilt Angle ◽  
Transfer Rate ◽  
Performance Criterion ◽  
Finned Tube ◽  
Finned Tubes ◽  
Global Performance

The thermal and flow performance of the circular annular finned tube heat exchanger with perforated fins were investigated numerically using ANSYS Fluent 2020 software, RNG k-e model with enhanced wall treatment, global performance criterion was introduced as evaluation factor of the heat exchanger performance, the parameters to be investigated were the number of holes, size of hole, tilt angle of the finned tube, fin height and spacing between fins. Agreement was found with literature that the tilt angle causes increase in heat transfer rate and increase in the pressure drop as well, but the change the global performance criterion as function to tilt angle depends on the fin heights, for higher fin heights the effective change of the pressure drop become greater than the increase in the heat transfer rate and the contrast occur in the cases of smaller fin heights, we have found that the perforation in tilted annular circular finned tubes causes an increase in the heat transfer rate and an enhancement in the total heat exchanger performance, increasing the number of holes will enhance the performance of the heat exchanger and the spacing increase reduces the heat exchanger performance.

Heat Transfer and Pressure Drop Characteristics of Finned Tube Banks in Heat Exchanger for Gas Turbine

2004 ◽  
Author(s):  
K. Kawaguchi ◽  
K. Okui ◽  
Y. Hasegawa
Keyword(s):  
Heat Transfer ◽  
Power Generation ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Thermal Power ◽  
Finned Tube ◽  
Finned Tubes ◽  
Thermal Power Generation ◽  
Reduction Of Energy Consumption ◽  
Tube Banks

In recent years the requirement for reduction of energy consumption has been increasing to solve the problems of the global warming and the shortage of petroleum resources. For example in the power generation field, as the thermal power generation occupied 60% of the power generation demand, the improvement of the thermal efficiency is required considerably. This paper described the heat transfer and pressure drop characteristics of the finned tube banks used for the heat exchanger in the thermal power generation. The characteristics were clarified by testing the serrated finned tubes banks for improvement of higher heat transfer and the conventional spiral finned tube banks under the same test conditions. The equations to predict heat transfer coefficient and pressure drop which are necessary on design of the heat exchanger were proposed.

scholarly journals Numerical Analysis of Heat Transfer and Pressure Drop in Helically Micro-Finned Tubes

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 754
Author(s):  
Muhammad Ammar Ali ◽  
Muhammad Sajid ◽  
Emad Uddin ◽  
Niaz Bahadur ◽  
Zaib Ali
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Friction Factor ◽  
Thermal Performance ◽  
Finned Tube ◽  
Smooth Tube ◽  
Working Fluid ◽  
Finned Tubes

In this study, the pressure drop and heat transfer characteristics of smooth tube and internal helically micro-finned tubes with two different fin-to-fin height ratios i.e., equal fin height and alternating fin height, are computationally analysed. The tube with alternating fin height is analysed for proof of concept of pressure drop reduction. A single phase steady turbulent flow model is used with a Reynolds number ranging from 12,000 to 54,000. Water is used as working fluid with inlet temperature of 55 °C and constant wall temperature of 20 °C is applied. Friction factor, heat transfer coefficient, Nusselt number, and Thermal Performance Index are evaluated and analysed. The numerical results are validated by comparison with the experimental and numerical data from literature. The results showed that the thermal performance is enhanced due to helically finned tube for a range of Reynolds numbers, but at the expense of increased pressure drop as compared to a smooth tube. The helically finned tube with alternating fin heights showed a 5% decrease in friction factor and <1% decrease in heat transfer coefficient when compared with the equal fin heights tube, making it a suitable choice for heat transfer applications.

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