scholarly journals Optimisation of the Geometric Parameters of Longitudinally Finned Air Cooler Tubes Operating in Mixed Convection Conditions

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 111
Author(s):  
Piotr Kopeć ◽  
Beata Niezgoda-Żelasko
Keyword(s):  
Heat Flow ◽  
Mixed Convection ◽  
Optimal Solution ◽  
Finned Tube ◽  
Geometric Parameters ◽  
Maximum Efficiency ◽  
Minimum Mass ◽  
Maximum Heat ◽  
Air Cooler ◽  
Finned Surface

The results of optimisation calculations presented in the article are related to longitudinally finned tubes of a heat pump evaporator operating under natural wind-induced flow of outdoor air conditions. The finned surface is characterised by an unusual, wavy fin shape. The article presents the methodology applied to seeking optimal geometric parameters of the finned tube in which thermal calculations were performed by modelling a mixed convection process on the finned surface using the finite volume method. In the case of maximising the heat flow with the minimum mass of the fins, the optimal solution was dominated by the minimum mass of the fins and thus geometric parameters correspond to the number of fins n = 6, fin height h = 0.065 and fin thickness s = 0.0015 m. Optimisation calculations made for maximum efficiency of the exchanger at constant mass indicated that the tube with ten fins (n = 10) with a height of h = 0.11 m and a thickness of s = 0.0018 m allowed maximum heat flow at the assumed mass of the fins in the exchanger tube model. The article proposes a simplified method of determining the optimal geometric parameters of the profile for any mass and maximum thermal efficiency.

HEAT AND MASS TRANSFER AND RESISTANCE CHARACTERISTICS OF EVAPORATIVE AIR COOLER WITH HIGH FINNED-TUBE BUNDLES

2018 ◽  
Vol 49 (17) ◽  
pp. 1705-1720 ◽  
Author(s):  
Qing Zhang ◽  
Xuesheng Wang ◽  
Weicheng Ruan ◽  
Qinzhu Chen ◽  
Zilong Liu
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Finned Tube ◽  
Tube Bundles ◽  
Air Cooler

Heat Exchanger Options for Dry Air Cooling for the sCO2 Brayton Cycle

2017 ◽  
Author(s):  
Anton Moisseytsev ◽  
Qiuping Lv ◽  
James J. Sienicki
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Cost Effective ◽  
Finned Tube ◽  
Air Cooling ◽  
Brayton Cycle ◽  
Dry Air ◽  
Air Atmosphere ◽  
Air Cooler ◽  
Forced Air

The capability to utilize dry air cooling by which heat is directly rejected to the air atmosphere heat sink is one of the benefits of the supercritical carbon dioxide (sCO2) energy conversion cycle. For the selection and analysis of the heat exchanger options for dry air cooling applications for the sCO2 cycle, two leading forced air flow design approaches have been identified and analyzed for this application; an air cooler consisting of modular finned tube air coolers; and an air cooler consisting of modular compact diffusion-bonded heat exchangers. The commercially available modular finned tube air cooler is found to be more cost effective and is selected as the reference for dry air cooling.

Significance of Delta Winglets on the Air Side Performance of Flat Finned Versus Wavy Finned-Tube Heat Exchangers

2020 ◽  
Author(s):  
Tariq Amin Khan ◽  
Nasir Mehdi Gardezi ◽  
Wei Li ◽  
Yang Zhou ◽  
Zahid Ayub
Keyword(s):  
Heat Transfer ◽  
Genetic Algorithm ◽  
Heat Exchangers ◽  
Three Dimensional ◽  
Finned Tube ◽  
Maximum Heat ◽  
Multi Objective ◽  
Multi Objective Genetic Algorithm ◽  
Maximum Heat Transfer ◽  
Side Flow

Abstract The performance on the air side flow is often limited due to its lower heat transfer coefficient. This work is related to numerical simulation to study the significance of employing delta winglets in flat finned and wavy finned-tube heat exchangers. For this purpose, three-dimensional simulation data and a multi-objective genetic algorithm are employed. The angle of attack (α) of delta winglets and Reynolds number varied from 15° to 75° and 500 to 1300, respectively. Employing delta winglets has increased the heat transfer per unit temperature and per unit volume (Z) and the fan power per unit core volume (E) for both flat finned and wavy finned-tube heat exchangers. To achieve a maximum heat transfer enhancement and a minimum friction factor, the optimal values of these parameters (Re and α) are calculated using the Pareto optimal strategy. For this purpose, CFD data, a surrogate model (neural network) and a multi-objective optimization genetic algorithm are combined. Results show that the performance of wavy finned-tube heat exchangers is higher than flat-finned tube heat exchangers which signify the importance of delta winglets in the wavy finned-tube heat exchangers.

Optimized Analysis of the Hollow Floor Based on the Niche Genetic Algorithms

2013 ◽  
Vol 421 ◽  
pp. 751-755
Author(s):  
Chuan Teng Huang ◽  
Zhi Jun Wang
Keyword(s):  
Genetic Algorithms ◽  
Optimal Solution ◽  
Threshold Value ◽  
Geometric Parameters ◽  
Optimization Analysis ◽  
Global Optimal Solution ◽  
Excellent Mechanical Property ◽  
Section Design ◽  
Global Optimal ◽  
Niche Genetic Algorithms

Nowadays, the hollow floor is widely used due to its excellent mechanical property and economic benefit.However, its related specification is absence of evaluation in geometric parameters. The optimized analysis aimed at the hollow floor under vertical load, the total cost of the hollow floor is considered as a objective function, the maximum deflection and the threshold value of the geometric parameters are considered as constrain conditions. The program, which introduces the section design and compiled by the python script, based on the niche genetic algorithms is used to analyze the optimization of a hollow floor. Comparing to the global optimal solution, the program achieves good results. It indicates that the niche genetic algorithms is efficient and suited for the optimization analysis of hollow floor. The above mentioned conclusions will be conducive to engineering design and further research in this field.

Effect of fin and tube configuration on heat transfer of an internally finned tube

2015 ◽  
Vol 25 (8) ◽  
pp. 1978-1999 ◽  
Author(s):  
Kailash Mohapatra ◽  
Dipti Prasad Mishra
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Transfer Rate ◽  
Flow Characteristics ◽  
Finned Tube ◽  
Maximum Heat ◽  
Content Type ◽  
Maximum Heat Transfer ◽  
Internally Finned Tube ◽  
Fluid Flow Characteristics

Purpose – The purpose of this paper is to determine the heat transfer and fluid flow characteristics of an internally finned tube for different flow conditions. Design/methodology/approach – Numerical investigation have been performed by solving the conservation equations of mass, momentum, energy with two equation-based k-eps model to determine the wall temperature, outlet temperature and Nusselt number of an internally finned tube. Findings – It has been found from the numerically investigation that there exists an optimum fin height and fin number for maximum heat transfer. It was also found that the heat transfer in T-shaped fin was highest compared to other shape. The saw type fins had a higher heat transfer rate compared to the plane rectangular fins having same surface area and the heat transfer rate was increasing with teeth number. Keeping the surface area constant, the shape of the duct was changed from cylindrical to other shape and it was found that the heat transfer was highest for frustum shape compared to other shape. Practical implications – The present computations could be used to predict the heat transfer and fluid flow characteristics of an internal finned tube specifically used in chemical and power plants. Originality/value – The original contribution of the paper was in the use of the two equation-based k-eps turbulent model to predict the maximum heat transfer through optimum design of fins and duct.

Static configuration of liquid films on horizontal tubes with low radial fins: implications for condensation heat transfer

1987 ◽  
Vol 410 (1838) ◽  
pp. 125-139 ◽  
Keyword(s):  
Heat Transfer ◽  
Liquid Films ◽  
Finned Tube ◽  
Tube Surface ◽  
Maximum Heat ◽  
Finned Tubes ◽  
Horizontal Tubes ◽  
Maximum Heat Transfer ◽  
Fluid Properties ◽  
Static Conditions

The configuration of a liquid film retained by surface tension forces on horizontal low-finned tubes has been analysed. It has been shown that liquid is retained on the upper parts of the tube surface previously regarded as 'unflooded'. The meniscus in a radial plane has been shown to approximate to a circular arc, with radius dependent only on the distance from the bottom of the tube, fluid properties and gravity. Four ‘flooding’ conditions are identified for trapezoidal-section fins and the positions around a tube at which these occur have been determined. Experimental measurements, for condensation of three fluids on tubes with rectangular-section fins, suggest that maximum heat-transfer en­hancement occurs when the spacing between the fins (the only geometric variable in these tests) is such as to maximize the ‘unblanked’ (by retained liquid under static conditions) finned tube surface area. The ‘unblanked’ or ‘active’ area is increased by using a radiused fillet at the fin root rather than a sharp corner. This might also be expected to give a corresponding increase in heat-transfer enhancement during condensation.

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