MEASUREMENTS AND ANALYSES OF COLBURN FACTOR IN FIN AND FLAT TUBE COMPACT HEAT EXCHANGERS

2019 ◽  
Author(s):  
Cristiano Tibiriçá
Keyword(s):  
Heat Exchangers ◽  
Flat Tube ◽  
Compact Heat Exchangers ◽  
Colburn Factor

NUMERICAL EVALUATION OF THERMO-HYDRAULIC PERFORMANCE IN FIN-AND-TUBE COMPACT HEAT EXCHANGERS WITH DIFFERENT TUBE CROSS-SECTIONS

2016 ◽  
Vol 78 (8-4) ◽  
Author(s):  
Ahmadali Gholami ◽  
Mazlan Abdul Wahid ◽  
Hussein A. Mohammed ◽  
A. Saat ◽  
M.F. Mohd Yasin ◽  
...  
Keyword(s):  
Heat Exchangers ◽  
Circular Tube ◽  
Hydraulic Performance ◽  
Flat Tube ◽  
Compact Heat Exchangers ◽  
Average Area ◽  
Flat Tubes ◽  
Goodness Factor ◽  
Circle Tube ◽  
Oval Tube

This study examined numericallythe Thermal-hydrodynamic properties of airflow in the fin-and-tube compact heat exchangers (FTCHEs) with considering different shapes of tubes in lowReynoldsnumbers. The influence of applying flat, oval and circular tube adjustments on the thermal and hydraulic characteristics of air flow were analyzed on the in-line tube arrangements. Establishing standard conditions, the study compared different geometries based on circular tubes of 10.459 mm diameter tubes with 25.4 mm longitudinal pitches and 25.4 mm transverse pitches. The other geometries of tubes were assumed in a stable and constant state preparing the same heat transfer surface area per unit volume as that of the nominal case. The results showed that the FTCHE with flat tubes gives the best area goodness factor (j/f) with in a certainrange of Reynoldsnumbers. In addition, FTCHE with flat tubes shown the best thermo-hydraulic performance and a significant augmentation of up to 10.83% and 35.63% in the average area goodness factor achieved accompanied by a decrease in the average friction factor of 17.02% and 43.41% in the flat tube case compared to the oval and circle tube shapes, respectively. It is concluded that the average area goodness factorfor the oval tube is about 25.04% higher than that of the circular tube, while the average friction factor for the oval tube is about 26.9% lower than that of the circular tube. This means that the flat tube has a better-combined thermal–hydraulic performance than the oval and circle tube.

An Experimental Study of Condensate Retention on the Air Side of Flat-Tube Heat Exchangers

2010 ◽  
Author(s):  
Deep Gupta ◽  
Young-Gil Park ◽  
Anthony M. Jacobi
Keyword(s):  
Heat Exchangers ◽  
Qualitative Evaluation ◽  
Side Surface ◽  
Air Cooling ◽  
Robust Solution ◽  
Flat Tube ◽  
Compact Heat Exchangers ◽  
Drainage Channels ◽  
Retention Characteristics ◽  
Condensed Water

Condensate on the air-side surface of flat-tube air-cooling heat exchangers can result in several adverse effects on the overall thermal hydraulic performance. In order to enhance the performance of compact heat exchangers under wet-surface conditions, promoting the drainage of condensed water is critical. Drainage channels on tube walls might provide a robust solution to promote condensate drainage from compact heat exchangers. A quantitative and qualitative evaluation of the effectiveness of drainage channels on the condensate retention characteristics of compact flat-tube louver-fin heat exchangers is presented. Various geometries of drainage channels are engraved on the surrogate tubes in contact with fin stock. Two fin designs are tested using dynamic dip testing method and a small wind tunnel. The data from the quantitative results and the visualization tests clearly show that the drainage channels reduce the condensate retention for one of the fin designs. The results also provide a comparison between drainage channels based on their geometry and dimensions.

A Comparison of Tapered and Straight Circular Pin-Fin Compact Heat Exchangers for Electronic Appliances

2009 ◽  
Vol 16 (3) ◽  
pp. 301-314
Author(s):  
A. Dewan ◽  
V. Bharti ◽  
V. Mathur ◽  
U. K. Saha ◽  
P. Patro
Keyword(s):  
Heat Exchangers ◽  
Compact Heat Exchangers ◽  
Pin Fin

modeFRONTIER for Virtual Design and Optimization of Compact Heat Exchangers

2014 ◽  
Author(s):  
Marco Carriglio ◽  
Alberto Clarich ◽  
Rosario Russo ◽  
Enrico Nobile ◽  
Paola Ranut
Keyword(s):  
Heat Exchangers ◽  
Virtual Design ◽  
Design And Optimization ◽  
Compact Heat Exchangers

scholarly journals A Three-Dimensional Numerical and Multi-Objective Optimal Design of Wavy Plate-Fins Heat Exchangers

Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 9
Author(s):  
Chao Yu ◽  
Xiangyao Xue ◽  
Kui Shi ◽  
Mingzhen Shao
Keyword(s):  
Heat Exchangers ◽  
Cfd Simulation ◽  
Three Dimensional ◽  
Basis Functions ◽  
Approximation Model ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Multi Objective Genetic Algorithm ◽  
Colburn Factor ◽  
Heat Exchange Efficiency

This paper presents a method for optimizing wavy plate-fin heat exchangers accurately and efficiently. It combines CFD simulation, Radical Basis Functions (RBF) with multi-objective optimization to improve the performance. The optimization of the Colburn factor j and the friction coefficient f is regarded as a multi-objective optimization problem, due to the existence of two contradictory goals. The approximation model was obtained by Radical Basis Functions, and the shape of the heat exchanger was optimized by multi-objective genetic algorithm (MOGA). The optimization results showed that j increased by 17.62% and f decreased by 20.76%, indicating that the heat exchange efficiency was significantly enhanced and the fluid structure resistance reduced. Then, from the aspects of field synergy and tubulence energy, the performance advantage of the optimized structure was further confirmed.

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