Second Law Analysis in a Partly Porous Double Pipe Heat Exchanger

2005 ◽  
Vol 73 (1) ◽  
pp. 60-65 ◽  
Author(s):  
Nadia Allouache ◽  
Salah Chikh
Keyword(s):  
Thermal Conductivity ◽  
Porous Medium ◽  
Heat Exchanger ◽  
Effective Thermal Conductivity ◽  
Entropy Generation ◽  
Inlet Temperature ◽  
Two Fluids ◽  
Annular Gap ◽  
Double Pipe ◽  
Pipe Heat

A combination of the first and second laws of thermodynamics has been utilized in analyzing the performance of a double pipe heat exchanger with a porous medium attached over the inner pipe. The goal of this work is to find the best conditions that allow the lowest rate of entropy generation due to fluid friction and heat transfer with respect to the considered parameters. Results show that the minimization of the rate of entropy generation depends on the porous layer thickness, its permeability, the inlet temperature difference between the two fluids, and the effective thermal conductivity of the porous substrate. An increase in the effective thermal conductivity of the porous medium seems to be thermodynamically advantageous. Unexpectedly, the fully porous annular gap yields the best results in terms of the rate of total entropy generation.

Turbulent flows in a spiral double-pipe heat exchanger

2019 ◽  
Vol 30 (1) ◽  
pp. 39-53 ◽  
Author(s):  
Zhe Tian ◽  
Ali Abdollahi ◽  
Mahmoud Shariati ◽  
Atefeh Amindoust ◽  
Hossein Arasteh ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Turbulent Flows ◽  
Heat Exchangers ◽  
Volume Fraction ◽  
Inlet Temperature ◽  
Content Type ◽  
Tube Heat Exchanger ◽  
Double Pipe ◽  
Pipe Heat

Purpose This paper aims to study the fluid flow and heat transfer through a spiral double-pipe heat exchanger. Nowadays using spiral double-pipe heat exchangers has become popular in different industrial segments due to its complex and spiral structure, which causes an enhancement in heat transfer. Design/methodology/approach In these heat exchangers, by converting the fluid motion to the secondary motion, the heat transfer coefficient is greater than that of the straight double-pipe heat exchangers and cause increased heat transfer between fluids. Findings The present study, by using the Fluent software and nanofluid heat transfer simulation in a spiral double-tube heat exchanger, investigates the effects of operating parameters including fluid inlet velocity, volume fraction of nanoparticles, type of nanoparticles and fluid inlet temperature on heat transfer efficiency. Originality/value After presenting the results derived from the fluid numerical simulation and finding the optimal performance conditions using a genetic algorithm, it was found that water–Al2O3 and water–SiO2 nanofluids are the best choices for the Reynolds numbers ranging from 10,551 to 17,220 and 17,220 to 31,910, respectively.

scholarly journals Improving thermal performance using Al2O3-water nanofluid in a double pipe heat exchanger filling with porous medium

2020 ◽  
Vol 24 (6 Part B) ◽  
pp. 4267-4275
Author(s):  
Qusay Jasim ◽  
Noah Saleh ◽  
Adnan Hussein
Keyword(s):  
Heat Transfer ◽  
Porous Media ◽  
Fluid Flow ◽  
Heat Exchanger ◽  
Volume Flow ◽  
Inlet Temperature ◽  
Flow Rates ◽  
Inside Diameter ◽  
Double Pipe ◽  
Pipe Heat

A double pipe heat exchanger is significant device for many industrial applications. In this paper, an experimental study using both porous media and nanofluid to enhance heat transfer in a double pipe heat exchanger is performed. The test rig has been fabricated with inner copper pipe of 1.10 m length, 16 mm, and 14 mm outside and inside diameter, respectively. While, the outer PVC pipe is 1 m length, 31 mm, and 27 mm outside and inside diameter, respectively. The inner pipe has been filling with 3 mm diameters of steel balls porous media. The experimental tests were performed utilizing alumina nanofluid (Al2O3-water) with two volume concentrations 0.5% and 1%. The volume flow-rates are in the range of (2-5) Lpm and 10 Lpm through inner and outer pipe, respectively. It was conducted with a constant 28?C inlet temperature of cold fluid-flow inside the inner pipe and 50?C inlet temperature of hot fluid-flow inside the outer pipe. Results indicated that the heat transfer enhanced as nanofluid volume concentrations and volume flow-rates increase. It was observed that effectiveness increases as increase of flow-rate and nanofluid concentrations.

Heat transfer and sensitivity analysis in a double pipe heat exchanger filled with porous medium

2017 ◽  
Vol 121 ◽  
pp. 124-137 ◽  
Author(s):  
Kamel Milani Shirvan ◽  
Soroush Mirzakhanlari ◽  
Soteris A. Kalogirou ◽  
Hakan F. Öztop ◽  
Mojtaba Mamourian
Keyword(s):  
Heat Transfer ◽  
Sensitivity Analysis ◽  
Porous Medium ◽  
Heat Exchanger ◽  
Double Pipe ◽  
Pipe Heat

The Second Law Quality of Energy Transformation in a Heat Exchanger

1990 ◽  
Vol 112 (2) ◽  
pp. 295-300 ◽  
Author(s):  
D. P. Sekulic
Keyword(s):  
Heat Exchanger ◽  
Heat Exchange ◽  
Entropy Generation ◽  
Exchange Process ◽  
Quantitative Measure ◽  
Inlet Temperature ◽  
Energy Transformation ◽  
Two Fluids ◽  
Heat Exchange Process

This paper presents the entropy generation (irreversibility) concept as a convenient method for estimating the quality of the heat exchange process in heat exchanger analysis. The entropy generation caused by finite temperature differences, scaled by the maximum possible entropy generation that can exist in an open system with two fluids, is used as the quantitative measure of the quality of energy transformation (the heat exchange process). This measure is applied to a two-fluid heat exchanger of arbitrary flow arrangement. The influence of different parameters (inlet temperature ratio, fluid flow heat capacity rate ratio, flow arrangements) and the heat exchanger thermal size (number of heat transfer units) on the quality of energy transformation for different types of heat exchangers is discussed. In this analysis it is assumed that the contribution of fluid friction to entropy generation is negligible.

scholarly journals Simulation and Analysis of Double Pipe Heat Exchanger

2021 ◽  
Vol 9 (VI) ◽  
pp. 2388-2394
Author(s):  
Nikheel Joshi
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Exchanger ◽  
Chemical Properties ◽  
Nano Particles ◽  
Cfd Analysis ◽  
Ansys Fluent ◽  
Nano Fluid ◽  
Double Pipe ◽  
Pipe Heat

A heat exchanger is a engineering device used for efficient heat transfer from one fluid to another at different temperatures and thermal in contact. Thermal properties of fluids play a significant role in various cooling and heating uses. Traditional fluids are of low thermal conductivity, so researchers are tried to enhance thermal conductivity by adding nano-particles. The model of double pipe heat exchanger was develop by using ANSYS workbench. Al2O3 mixed with water as a base fluid for analyzed their performance in double pipe heat exchanger. Al2O3 is a excellent material for heat transfer enhancement because, it has better physical as well as chemical properties. In this paper, we performed CFD analysis on double pipe heat exchanger using ANSYS FLUENT software by varying the concentrations of nano-particle (0.5%, 1%, 2%) in water. CFD analysis on double pipe heat exchanger by using Al2O3/water (nano-fluid) as cold fluid and water as a hot fluid. It is observed that nano-fluid with 2% concentration having more overall heat transfer coefficient.

scholarly journals Study the Effect of Granules Type of The Porous Medium on The Heat Transfer Enhancement for Double Pipe Heat Exchanger

2019 ◽  
Vol 26 (4) ◽  
pp. 43-49
Author(s):  
Ehsan Abbas ◽  
Shagul Mohammed
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Heat Exchanger ◽  
Cold Water ◽  
Hot Water ◽  
Transfer Enhancement ◽  
Copper Pipe ◽  
Inner Diameter ◽  
Double Pipe ◽  
Pipe Heat

The current study includes the effect of the type of porous medium on the heat transfer enhancement for double-pipe heat exchanger. Using the three types of the porous medium of balls (steel, ceramic and glass) with diameters (6.35, 6 and 7) mm respectively. The tests were carried out on a locally manufactured heat exchanger, consisting of a copper pipe with an inner diameter (20mm), an outer diameter (22mm) and a length of (1800mm), fixed inside a pipe made of galvanized iron with the same length of copper pipe with inner diameter (50mm) and thickness (5mm). The heat exchanger is insulated with a layer of glass wool to prevent leakage of heat to the area surrounding the exchanger. The tests carried out on the heat exchanger in four cases, the three cases for porous medium, also the case of exchanger without porous medium, and for all cases identical operating conditions, which is inlet temperature of hot, and cold water determined at (63 and 32)˚C and the number of Reynolds from (1100 to 9750) for cold water and (415 to 7500) for hot water. The experimental results showed that the highest thermal conductivity was obtained when the ceramic balls were used, which was estimated to be approximately (219.302) W/˚C and increased by (105.3%, 10.8%, 4.3%) for cases: without porous medium, glass balls and steel balls respectively. The effect of the pressure drop in the hot water side, was recorded the highest value for pressure drop when the ceramic balls were used and ranged from (0.5 to 19.5) mmHg and increased by (0.95%, 2.25%) when compared with the results of two cases for balls (steel and glass) respectively.

scholarly journals Numerical analysis reliability control for a double-pipe heat exchanger with virtual entropy generation method

2019 ◽  
Vol 48 (5) ◽  
pp. 1933-1945
Author(s):  
Tooran Tavangar ◽  
Behzad Siavash Amoli ◽  
Mojtaba Aghajani Delavar
Keyword(s):  
Heat Exchanger ◽  
Numerical Analysis ◽  
Entropy Generation ◽  
Reliability Control ◽  
Double Pipe ◽  
Pipe Heat

scholarly journals Numerical Investigation of Heat Transfer Enhancement of Double Pipe Heat Exchanger Using Metal Foam Fins

2019 ◽  
Vol 25 (6) ◽  
pp. 1-18
Author(s):  
Jenan Abdulhasan Hamzah ◽  
Mohammed A. Nima
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Exchanger ◽  
Metal Foam ◽  
Darcy Number ◽  
Inlet Temperature ◽  
Axial Distance ◽  
Study Results ◽  
Double Pipe ◽  
Pipe Heat

The influence of adding metal foam fins on the heat transfer characteristics of an air to water double pipe heat exchanger is numerically investigated. The hot fluid is water which flows in the inner cylinder whereas the cold fluid is air which circulates in the annular gap in parallel flow with water. Ten fins of metal foam (Porosity = 0.93), are added in the gap between the two cylinder, and distributed periodically with the axial distance. Finite volume method is used to solve the governing equations in porous and non-porous regions. The numerical investigations cover three values for Reynolds number (1000 ,1500, 2000), and Darcy number (1 x10-1, 1 x10-2, 1x10-3). The comparison between the two case with and without insertion the metal foam fins are examined in this study. Results show that the temperature of the inner pipe wall is affected by the Reynolds number, water inlet temperature, Darcy number variation. The resulting values and the behavior of the local and average coefficient of heat transfer are presented. The improvement in the mean coefficient of heat transfer (hm) is found to be 129 % with the using of the metal foam fins.  

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