scholarly journals Manufacturing and Characterization of Tube-Filled ZA27 Metal Foam Heat Exchangers

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1277
Author(s):  
Thomas Fiedler ◽  
Ryan Moore ◽  
Nima Movahedi

This study investigates the heat transfer performance of a novel ZA27 metal foam heat exchanger. An open-celled metal foam is combined with a thin-walled copper tube in a single-step casting process. The heat transfer between two separated water streams flowing through the copper tube and foam, respectively, is measured and compared to an equivalent shell tube heat exchanger arrangement. Heat transfer enhancement of up to 71% and a heat transfer rate exceeding 30 kW are observed and attributed to the increased surface area of the metallic foam. However, overall performance was limited by the inefficient heat transfer between the internal mass stream and the copper tube.

2018 ◽  
Vol 6 (3) ◽  
pp. 1-12
Author(s):  
Kamil Abdul Hussien

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.


2021 ◽  
Vol 1034 (1) ◽  
pp. 012045
Author(s):  
Herry Irawansyah ◽  
Abdul Ghofur ◽  
Rachmat Subagyo ◽  
Mastiadi Tamjidillah ◽  
Bagus Harits Pratama ◽  
...  

Author(s):  
Cenk Onan ◽  
Derya B. Ozkan ◽  
Levent Ceran

Internally grooved copper tubes are used extensively in HVAC applications, direct expansion batteries and air or water cooled heat exchangers. The advantage of internally grooved copper tubes in evaporator and condenser units is an increase in the refrigerant-side heat transfer coefficient. When an internally grooved tube heat exchanger and a smooth-tube heat exchanger with the same dimensions are compared, the overall heat transfer coefficient and convective heat transfer coefficient are found to increase in different ratios. In addition to this difference, the refrigerant side pressure is found to be a function of the groove geometry, pitch space and choice of refrigerant. In this study, which is different from previous studies in the literature performed using single internally grooved tube condensers and evaporators, refrigerant R404-A is studied in the internally grooved tube evaporator. The heat transfer in the evaporator described here is 30% better than that observed in a conventional smooth-copper-tube evaporator. In the internally grooved tube, the internal surface area is 68% larger than that inside the smooth reference tube. As a result, the convective heat transfer coefficient inside the internally grooved tube is found to be lower than that in the smooth tube.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Swanand Gaikwad ◽  
Ashish Parmar

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.


Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 968-980
Author(s):  
Xueping Du ◽  
Zhijie Chen ◽  
Qi Meng ◽  
Yang Song

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.


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