Heat Transfer Analysis of Shell-and-Helical-Coil Heat Exchangers

2016 ◽  
Author(s):  
Anthony Edward Morris ◽  
C. S. Wei ◽  
Runar Unnthorsson ◽  
Robert Dell
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Heat Exchangers ◽  
Transfer Rate ◽  
Green Roofs ◽  
Heat Transfer Analysis ◽  
Helical Coil ◽  
Straight Tube ◽  
Science And Art ◽  
Coil Heat

Since 2006, The Center for Innovation and Applied Technology (CIAT) at Cooper Union for the Advancement of Science and Art has been developing a system to use thermal pollution to heat the growth medium of green roofs. CIAT is researching various apparatus and techniques, including shell-and-tube and shell-and-coil heat exchangers, to improve its heated ground agricultural projects. There are limited recorded observations on shell-and-coil heat exchangers; therefore a laboratory work station was created of interchangeable components to test the efficiency of a variety of coil designs. This paper discusses the data collected on temperature, pressure, and flow rates for a straight tube and two different helical coils. The analysis of this data indicates the superiority of a helical coil design when compared to a straight tube design with respect to both rating and heat transfer rate. The same data analysis has lead to preliminary observations on how the contour properties of a helical coil influence the heat transfer rate through a coil. The authors intend to further this helical coil research to develop a useful mathematical model for determining efficient designs for shell-and-coil heat exchangers.

scholarly journals Experimental Research on Heat Transfer Characteristics of Helical Coil Heat Exchanger with Varying Pitch for laminar Fluid Flow

2019 ◽  
Vol 8 (3) ◽  
pp. 315-320
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Transfer Rate ◽  
Flow Rate ◽  
Transfer Rate ◽  
Helical Coil ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Coil Heat Exchanger ◽  
Coil Heat

To Study on rate of heat transfer in heat exchanger using helical coils has been studied by many researchers. There is less published literature available on varying pitch helical coil heat exchanger and detail characteristics of helical coil varying pitch by keeping constant curvature ratio considering heat exchange between fluid to fluid heat exchanger for laminar flow condition not available in the present available literature. Hence in present study three different coils with varying pitches are used to investigate the heat transfer characteristics of a Helical Coil Heat Exchanger. Hence coil of 25mm, 30mm, 35mm are used by keeping constant curvature ratio (=0.0667), experiment is conducted to study the influence of varying pitch on effectiveness, heat transfer rate, over all heat transfer co-efficient and Nusselt Number. The experiments is conducted in horizontal counter steady flow condition and changing the flow rate of hot fluid, pitch of helical coil heat exchanger. The results show that the varying pitch of helical coil heat exchanger has influence on heat transfer characteristics. The effectiveness of the helical coil heat exchanger is decreases with increase in mass flow rate of the hot fluid inside helical tube for varying pitch considered for study. The heat transfer rate of the helical coil heat exchanger is increases with increase in Dean Number of the hot fluid inside helical tube for varying pitch considered for study. The overall heat transfer coefficient increases with increasing hot water mass flow rate. The Nussult Number at different dean number increases for increasing helical coil pitch however the trend of average heat transfer rate for increasing M Number for varying pitch observed similar. By increasing the coil pitch of helical coil heat exchanger decreases Nussult Number, inside overall heat transfer coefficient, heat transfer rate and effectiveness.

Natural Convection Heat Transfer in a Shell and Helical Coil Heat Exchanger Using non-Newtonian Nanofluids

2020 ◽  
Vol 15 (2) ◽  
Author(s):  
B. Anil Kumar Naik ◽  
A. Venu Vinod
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Base Fluid ◽  
Convection Heat Transfer ◽  
Cuo Nanoparticles ◽  
Helical Coil ◽  
Natural Convection Heat Transfer ◽  
Coil Heat Exchanger ◽  
Coil Heat

AbstractNanofluids have gained much attention due to excellent thermal properties. In this study, natural convection heat transfer behavior of three different types of non-Newtonian nanofluids in a shell and helical coil heat exchanger has been investigated experimentally under unsteady state conditions. Nanofluids were prepared by dispersion of Al2O3, Fe2O3 and CuO nanoparticles in an aqueous solution of carboxymethyl cellulose (CMC) (base fluid). Nanofluids of different concentrations (0.2, 0.4, 0.6, 0.8 and 1.0 wt%) were prepared by dispersing Al2O3, Fe2O3 and CuO nanoparticles in base fluid using probe sonication process. In the present study, the effect of shell-side nanofluid concentration, tube-side fluid (heating medium) temperature and flow rate parameters on heat transfer has been investigated.Results indicated that the addition of nanofluid has intensified heat transfer as indicated by the higher temperature of nanofluid when compared to base fluid. Out of the three materials used in the study, CuO nanofluid attained the highest temperature because of its higher thermal conductivity. Heat transfer rate decreased with time continuously for all the experimental conditions. Enhancement in heat transfer initially was higher compared to later times. At longer time the enhancement is less due to the lower buoyancy forces prevailing due to lower driving force. A maximum enhancement in heat transfer rate of 29.5 % has been obtained initially. The effect of nanofluid concentration on heat transfer rate with time exhibited different behavior compared to the effect of inlet temperature and flow rate.

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.

Pressure Drop and Heat Transfer Characteristics of Louvered Fin Heat Exchangers

2013 ◽  
Vol 465-466 ◽  
pp. 500-504 ◽  
Author(s):  
Shahrin Hisham Amirnordin ◽  
Hissein Didane Djamal ◽  
Mohd Norani Mansor ◽  
Amir Khalid ◽  
Md Seri Suzairin ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Heat Transfer Rate ◽  
Heat Exchangers ◽  
Transfer Rate ◽  
Three Dimensional ◽  
Considerable Effect ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Louvered Fin

This paper presents the effect of the changes in fin geometry on pressure drop and heat transfer characteristics of louvered fin heat exchanger numerically. Three dimensional simulation using ANSYS Fluent have been conducted for six different configurations at Reynolds number ranging from 200 to 1000 based on louver pitch. The performance of this system has been evaluated by calculating pressure drop and heat transfer coefficient. The result shows that, the fin pitch and the louver pitch have a very considerable effect on pressure drop as well as heat transfer rate. It is observed that increasing the fin pitch will relatively result in an increase in heat transfer rate but at the same time, the pressure drop will decrease. On the other hand, low pressure drop and low heat transfer rate will be obtained when the louver pitch is increased. Final result shows a good agreement between experimental and numerical results of the louvered fin which is about 12%. This indicates the capability of louvered fin in enhancing the performance of heat exchangers.

A generalized moving-boundary algorithm to predict the heat transfer rate of counterflow heat exchangers for any phase configuration

2015 ◽  
Vol 79 ◽  
pp. 192-201 ◽  
Author(s):  
Ian H. Bell ◽  
Sylvain Quoilin ◽  
Emeline Georges ◽  
James E. Braun ◽  
Eckhard A. Groll ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Heat Exchangers ◽  
Transfer Rate ◽  
Moving Boundary

Thermal Assessment of Forced Convection Through Metal Foam Heat Exchangers

2011 ◽  
Vol 133 (11) ◽  
Author(s):  
A. Tamayol ◽  
K. Hooman
Keyword(s):  
Heat Transfer ◽  
Thermal Resistance ◽  
Forced Convection ◽  
Heat Transfer Rate ◽  
Heat Exchangers ◽  
Transfer Rate ◽  
Metal Foam ◽  
Convection Heat Transfer ◽  
Geometrical Parameters ◽  
Convection Heat

Using a thermal resistance approach, forced convection heat transfer through metal foam heat exchangers is studied theoretically. The complex microstructure of metal foams is modeled as a matrix of interconnected solid ligaments forming simple cubic arrays of cylinders. The geometrical parameters are evaluated from existing correlations in the literature with the exception of ligament diameter which is calculated from a compact relationship offered in the present study. The proposed, simple but accurate, thermal resistance model considers: the conduction inside the solid ligaments, the interfacial convection heat transfer, and convection heat transfer to (or from) the solid bounding walls. The present model makes it possible to conduct a parametric study. Based on the generated results, it is observed that the heat transfer rate from the heated plate has a direct relationship with the foam pore per inch (PPI) and solidity. Furthermore, it is noted that increasing the height of the metal foam layer augments the overall heat transfer rate; however, the increment is not linear. Results obtained from the proposed model were successfully compared with experimental data found in the literature for rectangular and tubular metal foam heat exchangers.

scholarly journals Heat Transfer Enhancement by Perforated and Louvred Fin Heat Exchangers

Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 400
Author(s):  
Miftah Altwieb ◽  
Rakesh Mishra ◽  
Aliyu M. Aliyu ◽  
Krzysztof J. Kubiak
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Heat Transfer Rate ◽  
Heat Exchangers ◽  
Transfer Rate ◽  
Reynolds Numbers ◽  
Transfer Enhancement ◽  
Flow Rates ◽  
Pressure Drops ◽  
Fin Design

Multi-tube multi-fin heat exchangers are extensively used in various industries. In the current work, detailed experimental investigations were carried out to establish the flow/heat transfer characteristics in three distinct heat exchanger geometries. A novel perforated plain fin design was developed, and its performance was evaluated against standard plain and louvred fins designs. Experimental setups were designed, and the tests were carefully carried out which enabled quantification of the heat transfer and pressure drop characteristics. In the experiments the average velocity of air was varied in the range of 0.7 m/s to 4 m/s corresponding to Reynolds numbers of 600 to 2650. The water side flow rates in the tubes were kept at 0.12, 0.18, 0.24, 0.3, and 0.36 m3/h corresponding to Reynolds numbers between 6000 and 30,000. It was found that the louvred fins produced the highest heat transfer rate due to the availability of higher surface area, but it also produced the highest pressure drops. Conversely, while the new perforated design produced a slightly higher pressure drop than the plain fin design, it gave a higher value of heat transfer rate than the plain fin especially at the lower liquid flow rates. Specifically, the louvred fin gave consistently high pressure drops, up to 3 to 4 times more than the plain and perforated models at 4 m/s air flow, however, the heat transfer enhancement was only about 11% and 13% over the perforated and plain fin models, respectively. The mean heat transfer rate and pressure drops were used to calculate the Colburn and Fanning friction factors. Two novel semiempirical relationships were derived for the heat exchanger’s Fanning and Colburn factors as functions of the non-dimensional fin surface area and the Reynolds number. It was demonstrated that the Colburn and Fanning factors were predicted by the new correlations to within ±15% of the experiments.

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