Local frosting behavior of a plated-fin and tube heat exchanger according to the refrigerant flow direction and surface treatment

2013 ◽  
Vol 64 ◽  
pp. 751-758 ◽  
Author(s):  
Kyoungmin Kim ◽  
Dong Rip Kim ◽  
Kwan-Soo Lee
Keyword(s):  
Heat Exchanger ◽  
Surface Treatment ◽  
Flow Direction ◽  
Tube Heat Exchanger

Characteristics of Inclined Fin-Tube Heat Exchanger for Compact Air Conditioner

2002 ◽  
Author(s):  
Haruaki Kanematsu ◽  
Kazuhiko Murakami
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
High Performance ◽  
Flow Direction ◽  
Numerical Approach ◽  
Air Conditioner ◽  
Large Space ◽  
Tube Heat Exchanger ◽  
Fin Tube ◽  
Inclined Angle

For saving space at an office or a clean room, it is needed to reduce the space of an air conditioner. It is effective to miniaturize a heat exchanger because it occupies the large space in the air conditioner. Three types of a heat exchanger that are an in-line tube and cut fins type, a staggered tube and cut fins type and a staggered tube and uncut fins type were investigated as four inclined angle tests of 0, 45, 60 and 80 degrees in a heat wind tunnel. The coefficients of flow friction and heat transfer rates were obtained from these experiments, and the characteristics of inclined heat exchanger were clarified by effects of tube arrangements, fin types and inclined angles against flow direction. As a numerical approach, two-dimensional steady models were applied on the staggered tube and the in-line tube by using BFC (Boundary-Fitted Coordinate Method); BFC is available to make grids for any install angle of the heat exchanger. The results of the numerical analysis visualized flow patterns and heat transfer in these heat exchangers. In case of 80-degrees angle, the flow makes dead area in a part of the heat exchanger, and it causes reducing performance of the heat exchanger. These results are available for improve a compact high performance heat exchanger.

Flow field simulation and stress analysis of a shell-tube heat exchanger with spiral bend tubes

2020 ◽  
pp. 2150100
Author(s):  
Binbin Qiu ◽  
Bowen Du ◽  
Yanna Li ◽  
Qingchuan Yang ◽  
Weixiong Chen ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Thermal Stress ◽  
Heat Exchanger ◽  
Flow Field ◽  
Flow Direction ◽  
Straight Tube ◽  
Pressure Drops ◽  
Tube Heat Exchanger ◽  
Porous Media Model ◽  
Experimental Values

The porous media model was improved to simulate the flow field of a shell-tube heat exchanger with spiral bend tubes. The improved porous medium model can be used to control the fluid flow direction. On the tube side, the streamline was along the spiral bend tubes. The fluid velocities and pressure drops on the tube and shell sides agree well with the experimental values. The fluid flow on the shell side is little affected by the spiral bend structure. The thermal stress of the spiral bend tubes was analyzed. The thermal stress of the spiral bend tubes is much smaller than the thermal stress of the straight tube. The thermal stress at the bend part decreases with the increase of bending angles.

scholarly journals Numerical analysis of the steam flow field in shell and tube heat exchanger

2016 ◽  
Vol 37 (2) ◽  
pp. 107-120 ◽  
Author(s):  
Jarosław Bartoszewicz ◽  
Leon Bogusławski
Keyword(s):  
Heat Exchanger ◽  
Numerical Analysis ◽  
Flow Direction ◽  
Thermal Power ◽  
Turbulence Models ◽  
Steam Flow ◽  
Inlet Section ◽  
Tube Heat Exchanger ◽  
Numerical Studies ◽  
Shell And Tube

Abstract In the paper, the results of numerical simulations of the steam flow in a shell and tube heat exchanger are presented. The efficiency of different models of turbulence was tested. In numerical calculations the following turbulence models were used: k-ε, RNG k-ε, Wilcox k-ω, Chen-Kim k-ε, and Lam-Bremhorst k-ε. Numerical analysis of the steam flow was carried out assuming that the flow at the inlet section of the heat exchanger were divided into three parts. The angle of steam flow at inlet section was determined individually in order to obtain the best configuration of entry vanes and hence improve the heat exchanger construction. Results of numerical studies were verified experimentally for a real heat exchanger. The modification of the inlet flow direction according to theoretical considerations causes the increase of thermal power of a heat exchanger of about 14%.

scholarly journals Study on the Effect of Oval Tubes on Airflow Turbulence Characteristics in Wind Tunnel

2020 ◽  
Vol 38 (2) ◽  
pp. 303-308
Author(s):  
Bo Zhao ◽  
Cheng Fu ◽  
Haitao Pei ◽  
Daxiong Liao ◽  
Bo Zhu
Keyword(s):  
Heat Exchanger ◽  
Wind Tunnel ◽  
Turbulence Intensity ◽  
Flow Direction ◽  
Structural Parameters ◽  
Simulation Method ◽  
Experimental Result ◽  
Turbulence Characteristics ◽  
Tube Heat Exchanger ◽  
Inflow Conditions

The flow Turbulence characteristics of finned oval tube heat exchanger used in wind tunnel were studied by using numerical simulation method. Firstly, the reliability of the numerical method was verified by the experimental results. And then the research was focused on the comparative analysis of the characteristics of turbulent flow downstream of heat exchanger under different inflow conditions, and the influence of the tubes number and fins spacing on the airflow turbulence and the flow field distribution downstream of heat exchanger were obtained too. The results indicate that oval tubes have a significant effect for improving the flow quality when incoming flow is inhomogeneous, and the velocity distribution behind heat exchanger tends to become uniform. Inflow conditions have a slight effect on the turbulence intensity behind heat exchanger, which mainly depends on the structural parameters of heat transfer tubes. The turbulence intensity decays very quickly in the flow direction. The value is reduced to 7.5% at the cross section 600 mm downstream of the heat exchanger inlet, which agrees well with the experimental result.

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