scholarly journals Discussion: “A Parametric Analysis of the Performance of Internally Finned Tubes for Heat Exchanger Application” (Webb, R. L., and Scott, M. J., 1980, ASME J. Heat Transfer, 102, pp. 38–43)

1980 ◽  
Vol 102 (3) ◽  
pp. 586-587 ◽  
Author(s):  
A. Bejan
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Parametric Analysis ◽  
Finned Tubes

Shellside Waterflow Pressure Drop Distribution Measurements in an Industrial-Sized Test Heat Exchanger

1988 ◽  
Vol 110 (1) ◽  
pp. 60-67 ◽  
Author(s):  
H. Halle ◽  
J. M. Chenoweth ◽  
M. W. Wambsganss
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Operating Cost ◽  
Power Requirement ◽  
Pressure Drops ◽  
Pressure Losses ◽  
Finned Tubes ◽  
Heat Exchanger Design ◽  
Isothermal Water

Throughout the life of a heat exchanger, a significant part of the operating cost arises from pumping the heat transfer fluids through and past the tubes. The pumping power requirement is continuous and depends directly upon the magnitude of the pressure losses. Thus, in order to select an optimum heat exchanger design, it is is as important to be able to predict pressure drop accurately as it is to predict heat transfer. This paper presents experimental measurements of the shellside pressure drop for 24 different segmentally baffled bundle configurations in a 0.6-m (24-in.) diameter by 3.7-m (12-ft) long shell with single inlet and outlet nozzles. Both plain and finned tubes, nominally 19-mm (0.75-in.) outside diameter, were arranged on equilateral triangular, square, rotated triangular, and rotated square tube layouts with a tube pitch-to-diameter ratio of 1.25. Isothermal water tests for a range of Reynolds numbers from 7000 to 100,000 were run to measure overall as well as incremental pressure drops across sections of the exchanger. The experimental results are given and correlated with a pressure drop versus flowrate relationship.

Study on Free Convection Heat Transfer in a Finned Tube Array

2015 ◽  
Vol 23 (01) ◽  
pp. 1550007 ◽  
Author(s):  
Ryoji Katsuki ◽  
Tsutomu Shioyama ◽  
Chikako Iwaki ◽  
Tadamichi Yanazawa
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Transfer Coefficient ◽  
Finned Tube ◽  
Average Heat Transfer Coefficient ◽  
Average Heat ◽  
Finned Tubes ◽  
Air Cooled Heat Exchanger ◽  
The Heat Transfer Coefficient

We have been developing a free convection air cooled heat exchanger without power supply to improve economic efficiency and mechanical reliability. However, this heat exchanger requires a larger installation area than the forced draft type air cooled heat exchanger since a large heating surface is needed to compensate for the small heat transfer by natural convection. Therefore, we have been investigating a heat exchanger consisting of an array of finned tubes and chimney to increase the heat transfer coefficient. Since the heat transfer characteristics of finned tube arrays have not been clarified, we conducted experiments with a finned tube array to determine the relation between the configuration of finned tubes and the heat transfer coefficient of a tube array. The results showed that the average heat transfer coefficient increased with pitch in the vertical direction, and became constant when the pitch was over five times the fin diameter. The average heat transfer coefficient was about 1.4 times higher than that of a single finned tube in free space. The ratio of the average heat transfer coefficient of the finned tube array with chimney to that of a single finned tube was found to be independent of the difference in temperature between the tube surface and air.

An Investigation of Heat Transfer and Pressure Drop Enhancement of Various Perforated Circular Finned Tubes at Different Tube Tilt Angles

2021 ◽  
pp. 10295-10338
Author(s):  
Yahya Yaser Shanyour AL-Salman, Ali Sabri Abbas
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Heat Transfer Rate ◽  
Tilt Angle ◽  
Transfer Rate ◽  
Performance Criterion ◽  
Finned Tube ◽  
Finned Tubes ◽  
Global Performance

The thermal and flow performance of the circular annular finned tube heat exchanger with perforated fins were investigated numerically using ANSYS Fluent 2020 software, RNG k-e model with enhanced wall treatment, global performance criterion was introduced as evaluation factor of the heat exchanger performance, the parameters to be investigated were the number of holes, size of hole, tilt angle of the finned tube, fin height and spacing between fins. Agreement was found with literature that the tilt angle causes increase in heat transfer rate and increase in the pressure drop as well, but the change the global performance criterion as function to tilt angle depends on the fin heights, for higher fin heights the effective change of the pressure drop become greater than the increase in the heat transfer rate and the contrast occur in the cases of smaller fin heights, we have found that the perforation in tilted annular circular finned tubes causes an increase in the heat transfer rate and an enhancement in the total heat exchanger performance, increasing the number of holes will enhance the performance of the heat exchanger and the spacing increase reduces the heat exchanger performance.

Heat Transfer and Pressure Drop Characteristics of Finned Tube Banks in Heat Exchanger for Gas Turbine

2004 ◽  
Author(s):  
K. Kawaguchi ◽  
K. Okui ◽  
Y. Hasegawa
Keyword(s):  
Heat Transfer ◽  
Power Generation ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Thermal Power ◽  
Finned Tube ◽  
Finned Tubes ◽  
Thermal Power Generation ◽  
Reduction Of Energy Consumption ◽  
Tube Banks

In recent years the requirement for reduction of energy consumption has been increasing to solve the problems of the global warming and the shortage of petroleum resources. For example in the power generation field, as the thermal power generation occupied 60% of the power generation demand, the improvement of the thermal efficiency is required considerably. This paper described the heat transfer and pressure drop characteristics of the finned tube banks used for the heat exchanger in the thermal power generation. The characteristics were clarified by testing the serrated finned tubes banks for improvement of higher heat transfer and the conventional spiral finned tube banks under the same test conditions. The equations to predict heat transfer coefficient and pressure drop which are necessary on design of the heat exchanger were proposed.

The Variation in Effectiveness of Low-Finned Tubes Within a Shell-and-Tube Heat Exchanger for Supercritical CO2

2012 ◽  
Author(s):  
Patrick M. Fourspring ◽  
Joseph P. Nehrbauer
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Heat Exchanger ◽  
Thermal Conductance ◽  
Heat Transfer Area ◽  
Shell Side ◽  
Additional Heat ◽  
Tube Heat Exchanger ◽  
Finned Tubes ◽  
Shell And Tube

Low-finned tubes can be effective in baffled flow heat exchangers, if the heat transfer coefficients on either side of the heat exchanger differ greatly and therefore limit the thermal conductance of the heat exchanger. Low-finned tubes can increase thermal conductance by providing additional heat transfer area on the limiting side. The height and the spacing of the low-fins must be greater than the thickness of the thermal boundary layer on the low-finned side of the heat exchanger. Otherwise, the effectiveness of the additional area that the low-finned tubes provide will be reduced. The boundary layer thickness is dependent on the velocity and the thermophysical properties of the fluids. Therefore, in a standard shell-and-tube heat exchanger, the number of heat exchanger shell-side baffles needs to be properly considered to provide the correct shellside velocity without introducing too much pressure drop. Testing of a shell-and-tube heat exchanger containing low-finned tubes varied the flow rate and pressure of the supercritical CO2 on the shell side as water provided the cooling on the tube side. The testing maintained the temperature and pressure of the CO2 above the critical point in order to determine the changes in the effectiveness of the low-finned tubes and thus the heat transfer rate of the heat exchanger. The results show that the additional heat transfer area provided by the low-finned tubes will remain fully effective, even as the supercritical fluid nears its critical point or a pseudo-critical temperature. This result also supports (but is not sufficient to prove) the guidance to limit the estimated thickness of the thermal boundary layer to the fin height and twice the fin spacing to ensure the additional heat transfer area provided by the low-finned tubes remain effective.

scholarly journals Design and Analysis of Air-Cooled Fin and Tube Heat Exchanger with Smaller Diameter Micro Finned Tubes using R32 in Replacement of R410A

2019 ◽  
Vol 8 (2) ◽  
pp. 2485-2489 ◽  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Transfer Coefficient ◽  
Ozone Depletion ◽  
Air Conditioning ◽  
Tube Heat Exchanger ◽  
Finned Tubes ◽  
Ozone Depletion Potential ◽  
Depletion Potential

Difluoromethane (HFC32) is the perfect replacement of R410A due to its zero ozone depletion Potential and lower Global warming potential (GWP as 675) that is much less than R410A (2088) and Zero Ozone Depletion Potential. R32 refrigerant can achieve higher heat transfer coefficients with less quantity of refrigerant charge when compared to R410A. Fin and Tube heat exchangers (FTHE) are widely used in the refrigeration, air conditioning industries and in many other applications to exchange or transfer the heat from refrigerant or working fluid and to the sink. The aim of this paper is to calculate the Heat transfer coefficient, pressure drop and heat load of refrigerants in Air-cooled Fin and Tube heat exchanger. Here FTHE is used as a condenser in one TR residential air conditioning application and their comparison using R32 and R410A refrigerants. To study the behaviour of two refrigerants in liquid phase, two phase (liquid and vapor phase) and vapor phases inside the condenser. Here the airflow to the condenser is counter flow. Materials used were Aluminium for fins and copper for tubes to achieve greater heat transfer coefficient. Here fin and tube material combination is very important because of their material properties. Optimizing the design of FTHE, i.e. selecting the micro finned tubes to generate turbulence in refrigerant flow, which results in enhancement of heat transfer coefficient. Slit type fin is selected for fins. The micro finned copper tubes with smaller inner diameter can save the material cost. Coil Designer a simulation software used for the design and analysis of FTHE

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