An advanced turbulator with blades and semi-conical section for heat transfer improvement in a helical double tube heat exchanger

2021 ◽  
Vol 28 (11) ◽  
pp. 3491-3506
Author(s):  
Seyed Hossein Hashemi Karouei ◽  
Seyed Soheil Mousavi Ajarostaghi ◽  
Saman Rashidi ◽  
Elham Hosseinirad
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Tube Heat Exchanger ◽  
Conical Section ◽  
Heat Transfer Improvement

Air-Side Heat-Transfer Enhancement by a New Winglet-Type Vortex Generator Array in a Plain-Fin Round-Tube Heat Exchanger

2010 ◽  
Vol 132 (7) ◽  
Author(s):  
J. He ◽  
L. Liu ◽  
A. M. Jacobi
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Vortex Generator ◽  
Round Tube ◽  
Number Range ◽  
Tube Heat Exchanger ◽  
Large Pair ◽  
Goodness Factor ◽  
The Impact ◽  
Heat Transfer Improvement

The impact of a vortex-generation technique for air-side heat-transfer improvement is experimentally investigated through full-scale wind-tunnel testing of a plain-fin round-tube heat exchanger under dry-surface conditions. Inspired by the formation locomotion of animals in nature, a new vortex generator (VG) array deployed in a “V” is proposed in the present work, aiming to create constructive interference between vortices. The array is composed of two delta-winglet pairs and placed at an attack angle of 10 deg or 30 deg. Its effectiveness is compared with a baseline configuration and two conventional single-pair designs placed at 30 deg, a small pair with half the area of the array and a large pair with the same area as the array. The frontal air velocity considered ranges from 2.3 m/s to 5.5 m/s, corresponding to a Reynolds number range based on the hydraulic diameter of 1400–3400. The experimental results show little impact of the 10 deg array and a moderate heat-transfer improvement of up to 32% for the small pair, both introducing additional pressure loss of approximately 20–40%. For the 30 deg array and the large pair, similar augmentation of 25–55% in air-side heat-transfer coefficient is obtained accompanied by average pressure drop penalties of 90% and 140%, respectively. Performance evaluation using the criteria of the modified area goodness factor and the volume goodness factor indicates the superiority of the heat exchanger enhanced by the 30 deg array among all the investigated VGs. The VG array is found more effective at comparatively low Reynolds numbers, representative of many heating, ventilation, air-conditioning, and refrigeration applications and compact heat-exchanger designs.

Experimental Investigation of Heat Transfer Enhancement by Using Different Number of Fins in Circular Tube

2018 ◽  
Vol 6 (3) ◽  
pp. 1-12
Author(s):  
Kamil Abdul Hussien
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Cold Water ◽  
Finned Tube ◽  
Hot Water ◽  
Copper Tube ◽  
Smooth Tube ◽  
Tube Heat Exchanger ◽  
Mass Flow Rates ◽  
Flow Heat

Abstract-The present work investigates the enhancement of heat transfer by using different number of circular fins (8, 10, 12, 16, and 20) in double tube counter flow heat exchanger experimentally. The fins are made of copper with dimensions 66 mm OD, 22 mm ID and 1 mm thickness. Each fin has three of 14 mm diameter perforations located at 120o from each to another. The fins are fixed on a straight smooth copper tube of 1 m length, 19.9 mm ID and 22.2 mm OD. The tube is inserted inside the insulated PVC tube of 100 mm ID. The cold water is pumped around the finned copper tube, inside the PVC, at mass flow rates range (0.01019 - 0.0219) kg/s. The Reynold's number of hot water ranges (640 - 1921). The experiment results are obtained using six double tube heat exchanger (1 smooth tube and the other 5 are finned one). The results, illustrated that the heat transfer coefficient proportionally with the number of fin. The results also showed that the enhancement ratio of heat transfer for finned tube is higher than for smooth tube with (9.2, 10.2, 11.1, 12.1 13.1) times for number of fins (8, 10, 12, 16 and 20) respectively.

Numerical simulation of the effect of baffle cut and baffle spacing on shell side heat exchanger performance using CFD

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Swanand Gaikwad ◽  
Ashish Parmar
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Numerical Results ◽  
Shell Side ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
Two Parameters

AbstractHeat exchangers possess a significant role in energy transmission and energy generation in most industries. In this work, a three-dimensional simulation has been carried out of a shell and tube heat exchanger (STHX) consisting of segmental baffles. The investigation involves using the commercial code of ANSYS CFX, which incorporates the modeling, meshing, and usage of the Finite Element Method to yield numerical results. Much work is available in the literature regarding the effect of baffle cut and baffle spacing as two different entities, but some uncertainty pertains when we discuss the combination of these two parameters. This study aims to find an appropriate mix of baffle cut and baffle spacing for the efficient functioning of a shell and tube heat exchanger. Two parameters are tested: the baffle cuts at 30, 35, 40% of the shell-inside diameter, and the baffle spacing’s to fit 6,8,10 baffles within the heat exchanger. The numerical results showed the role of the studied parameters on the shell side heat transfer coefficient and the pressure drop in the shell and tube heat exchanger. The investigation shows an increase in the shell side heat transfer coefficient of 13.13% when going from 6 to 8 baffle configuration and a 23.10% acclivity for the change of six baffles to 10, for a specific baffle cut. Evidence also shows a rise in the pressure drop with an increase in the baffle spacing from the ranges of 44–46.79%, which can be controlled by managing the baffle cut provided.

scholarly journals Characterization of heat transfer on concentric tube heat exchanger using ethylene glycol/TiO2 nanofluid

2021 ◽  
Vol 1034 (1) ◽  
pp. 012045
Author(s):  
Herry Irawansyah ◽  
Abdul Ghofur ◽  
Rachmat Subagyo ◽  
Mastiadi Tamjidillah ◽  
Bagus Harits Pratama ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Ethylene Glycol ◽  
Tube Heat Exchanger

scholarly journals Experimental analysis and ANN prediction on performances of finned oval-tube heat exchanger under different air inlet angles with limited experimental data

Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 968-980
Author(s):  
Xueping Du ◽  
Zhijie Chen ◽  
Qi Meng ◽  
Yang Song
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Heat Exchanger ◽  
Correlation Equation ◽  
Tube Heat Exchanger ◽  
Flow Friction ◽  
Air Inlet ◽  
Comparison Results ◽  
Wide Range ◽  
Oval Tube

Abstract A high accuracy of experimental correlations on the heat transfer and flow friction is always expected to calculate the unknown cases according to the limited experimental data from a heat exchanger experiment. However, certain errors will occur during the data processing by the traditional methods to obtain the experimental correlations for the heat transfer and friction. A dimensionless experimental correlation equation including angles is proposed to make the correlation have a wide range of applicability. Then, the artificial neural networks (ANNs) are used to predict the heat transfer and flow friction performances of a finned oval-tube heat exchanger under four different air inlet angles with limited experimental data. The comparison results of ANN prediction with experimental correlations show that the errors from the ANN prediction are smaller than those from the classical correlations. The data of the four air inlet angles fitted separately have higher precisions than those fitted together. It is demonstrated that the ANN approach is more useful than experimental correlations to predict the heat transfer and flow resistance characteristics for unknown cases of heat exchangers. The results can provide theoretical support for the application of the ANN used in the finned oval-tube heat exchanger performance prediction.

Sign in / Sign up

Export Citation Format

Share Document