Heat Transfer and Friction Factor Data for Gap-Helical Screen Fin Counterflow Heat Exchanger

1994 ◽  
pp. 1607-1613
Author(s):  
E. B. Ratts ◽  
J. L. Smith ◽  
Y. Iwasa
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Friction Factor ◽  
Factor Data

Heat Transfer Performance of Different Nanofluids Flows in a Helically Coiled Heat Exchanger

2013 ◽  
Vol 832 ◽  
pp. 160-165 ◽  
Author(s):  
Mohammad Alam Khairul ◽  
Rahman Saidur ◽  
Altab Hossain ◽  
Mohammad Abdul Alim ◽  
Islam Mohammed Mahbubul
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Friction Factor ◽  
Heat Exchangers ◽  
Heat Transfer Performance ◽  
Volume Concentration ◽  
Transfer Performance

Helically coiled heat exchangers are globally used in various industrial applications for their high heat transfer performance and compact size. Nanofluids can provide excellent thermal performance of this type of heat exchangers. In the present study, the effect of different nanofluids on the heat transfer performance in a helically coiled heat exchanger is examined. Four different types of nanofluids CuO/water, Al2O3/water, SiO2/water, and ZnO/water with volume fractions 1 vol.% to 4 vol.% was used throughout this analysis and volume flow rate was remained constant at 3 LPM. Results show that the heat transfer coefficient is high for higher particle volume concentration of CuO/water, Al2O3/water and ZnO/water nanofluids, while the values of the friction factor and pressure drop significantly increase with the increase of nanoparticle volume concentration. On the contrary, low heat transfer coefficient was found in higher concentration of SiO2/water nanofluids. The highest enhancement of heat transfer coefficient and lowest friction factor occurred for CuO/water nanofluids among the four nanofluids. However, highest friction factor and lowest heat transfer coefficient were found for SiO2/water nanofluids. The results reveal that, CuO/water nanofluids indicate significant heat transfer performance for helically coiled heat exchanger systems though this nanofluids exhibits higher pressure drop.

CFD SIMULATION OF A PLATE HEAT EXCHANGER WITH TRAPEZOIDAL CHEVRON

2016 ◽  
Vol 78 (8-4) ◽  
Author(s):  
Chin Yung Shin ◽  
Normah Mohd-Ghazali
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Heat Exchanger ◽  
Friction Factor ◽  
Cfd Simulation ◽  
General Pattern ◽  
Plate Heat Exchanger ◽  
Plate Heat ◽  
Flow Configuration ◽  
Heat Transfer Capacity

In this research, the trapezoidal shaped chevron plate heat exchanger (PHE) is simulated using computational fluid dynamics (CFD) software to determine its heat transfer capacity and friction factor. The PHE is modelled with chevron angles from 30° to 60°, and also the performances are compared with the plain PHE. The validation is done by comparing simulation result with published references using 30° trapezoidal chevron PHE. The Nusselt number and friction factor obtained from simulation model is plotted against different chevron angles. The Nusselt number and friction factor is also compared with available references, which some of the references used sinusoidal chevron PHE. The general pattern of Nusselt number and friction factor with increasing chevron angle agrees with the references. The heat transfer capacity found in current study is higher than the references used, and at the same time, the friction factor also increased. Besides this, it is also found that the counter flow configuration has better heat transfer capacity performance than the parallel flow configuration.

Experimental Investigation of Coil Curvature Effect on Heat Transfer and Pressure Drop Characteristics of Shell and Coil Heat Exchanger

2014 ◽  
Vol 7 (1) ◽  
Author(s):  
M. R. Salem ◽  
K. M. Elshazly ◽  
R. Y. Sakr ◽  
R. K. Ali
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Heat Exchanger ◽  
Friction Factor ◽  
Heat Exchangers ◽  
Average Nusselt Number ◽  
Transfer Coefficients ◽  
Nusselt Numbers ◽  
Fanning Friction Factor ◽  
Coil Heat

The present work experimentally investigates the characteristics of convective heat transfer in horizontal shell and coil heat exchangers in addition to friction factor for fully developed flow through the helically coiled tube (HCT). The majority of previous studies were performed on HCTs with isothermal and isoflux boundary conditions or shell and coil heat exchangers with small ranges of HCT configurations and fluid operating conditions. Here, five heat exchangers of counter-flow configuration were constructed with different HCT-curvature ratios (δ) and tested at different mass flow rates and inlet temperatures of the two sides of the heat exchangers. Totally, 295 test runs were performed from which the HCT-side and shell-side heat transfer coefficients were calculated. Results showed that the average Nusselt numbers of the two sides of the heat exchangers and the overall heat transfer coefficients increased by increasing coil curvature ratio. The average increase in the average Nusselt number is of 160.3–80.6% for the HCT side and of 224.3–92.6% for the shell side when δ increases from 0.0392 to 0.1194 within the investigated ranges of different parameters. Also, for the same flow rate in both heat exchanger sides, the effect of coil pitch and number of turns with the same coil torsion and tube length is remarkable on shell average Nusselt number while it is insignificant on HCT-average Nusselt number. In addition, a significant increase of 33.2–7.7% is obtained in the HCT-Fanning friction factor (fc) when δ increases from 0.0392 to 0.1194. Correlations for the average Nusselt numbers for both heat exchanger sides and the HCT Fanning friction factor as a function of the investigated parameters are obtained.

Heat Transfer and Friction Factor of Coil-Springs Inserted in the Horizontal Concentric Tubes

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Haydar Eren ◽  
Nevin Celik ◽  
Seyba Yildiz ◽  
Aydın Durmus
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Friction Factor ◽  
Reynolds Numbers ◽  
Incline Angle ◽  
Coil Spring ◽  
Heat Transfer Characteristics ◽  
Dominant Effect ◽  
Significant Augmentation ◽  
Empty Tube

The goal of this investigation is to obtain definitive information about the heat transfer characteristics of circular coil-spring turbulators. This is achieved by measuring the wall temperatures on the inner tube of the exchanger. Also the inlet and outlet temperatures and pressure loss of the fluid are measured. These results are parametrized by Reynolds numbers (2500<Re<12,000), outer diameters of the springs (Ds=7.2 mm, 9.5 mm, 12 mm, and 13 mm), numbers of the springs (n=4, 5, and 6), and the incline angles of the springs (θ=0 deg, 7 deg, and 10 deg). Additionally, another goal of this work is to quantify the friction factor f of the turbulated heat exchanger system with respect to aforementioned parametric values. As a result, it is found that increasing spring number, spring diameter, and incline angle result in significant augmentation on heat transfer, comparatively 1.5–2.5 times of the results of a smooth empty tube. By the way, friction factor increases 40–80 times of the results found for a smooth tube. Furthermore, as a design parameter, the incline angle has the dominant effect on heat transfer and friction loss while spring number has the weakest effect.

scholarly journals Heat transfer performance and friction factor of various nanofluids in a double-tube counter flow heat exchanger

2020 ◽  
Vol 24 (6 Part A) ◽  
pp. 3601-3612
Author(s):  
Dan Zheng ◽  
Jin Wang ◽  
Yu Pang ◽  
Zhanxiu Chen ◽  
Bengt Sunden
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Exchanger ◽  
Friction Factor ◽  
Flow Resistance ◽  
Heat Transfer Performance ◽  
Weight Fraction ◽  
Transfer Performance ◽  
Tube Heat Exchanger ◽  
High Heat Transfer

Experimental research was conducted to reveal the effects of nanofluids on heat transfer performance in a double-tube heat exchanger. With nanoparticle weight fraction of 0.5-2.0% and Reynolds number of 4500-14500, the flow resistance and heat transfer were analyzed by using six nanofluids, i.e., CuO-water, Al2O3-water, Fe3O4-water, ZnO-water, SiC-water, SiO2-water nanofluids. Results show that SiC-water nanofluid with a weight concentration of 1.5% provides the best improvement of heat transfer performance. 1.0% CuO-water and 0.5% SiO2-water nanofluids have lower friction factors in the range of Reynolds number from 4500-14500 compared to the other nanofluids. Based on test results of heat transfer performance and flow resistance, the 1.0% CuO-water nanofluid shows a great advantage due to a relatively high heat transfer performance and a low friction factor. Finally, empirical formulae of Nusselt numbers for various nanofluids were established based on experimental data tested in the double-tube heat exchanger.

Experimental and Numerical Analyses of Friction Factors in Offset Strip Fin Heat Exchangers

2007 ◽  
Author(s):  
Aihua Wang ◽  
Samir F. Moujaes ◽  
Yitung Chen ◽  
Valery Ponyavin
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Heat Exchanger ◽  
Friction Factor ◽  
Heat Exchangers ◽  
Experimental Measurements ◽  
Test Rig ◽  
Compact Heat Exchangers ◽  
Friction Factors ◽  
Offset Strip Fin

Heat transfer in compact heat exchangers is augmented by the introduction of the offset strip fins. With the breakdown of the thermal and hydro boundary layers to boost heat transfer, the fins increase the friction power. Two heat exchangers of different fin geometries structures were built and tested. The results of the study show that the round-edge-fin heat exchanger has the smaller friction factor. A test rig was constructed to measure the friction factor of the offset strip fin heat exchangers with air. A modified hydraulic diameter was used to calculate the main parameters. The computational fluid dynamics package FLUENT was used to predict the flow in the heat exchanger. The numerical investigation was conducted and compared with experimental measurements.

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