Enhanced heat transfer in tubes based on vascular heat exchangers in fish: Experimental investigation

Heat transfer enhancement in heat exchangers results in thermal efficiency and energy saving. In double-pipe heat exchangers (DPHEs), extended or augmented fins in the annulus of the two concentric pipes, i.e., at the outer surface of the inner pipe, are used to extend the surface of contact for enhancing heat transfer. In this article, an innovative diamond-shaped design of extended fins is proposed for DPHEs. This type of fin is considered for the first time in the design of DPHEs. The triangular-shaped and rectangular-shaped fin designs of DPHE, available in the literature, can be recovered as special cases of the proposed design. An h-adaptive finite element method is employed for the solution of the governing equations. The results are computed for various performance measures against the emerging parameters. The results dictate that the optimal configurations of the diamond-shaped fins in the DPHE for an enhanced heat transfer are recommended as follows: If around 4–6, 8–12, or 16–32 fins are to be placed in the DPHE, then the height of the fins should be 20%, 80%, or 100%, respectively, of the annulus width. If frictional loss of heat is also to be considered, then for fin-heights of 20–80% and 100% of the annulus width, the placement of 4 and 8 diamond-shaped fins, respectively, is recommended for an enhanced heat transfer. These recommendations are for the radii ratio (i.e., the ratio of the inner pipe radius to that of the outer pipe) of 0.25. The recommendations are be modified if the radii ratio is altered.

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Enhanced heat transfer performance for multi-tube heat exchangers with various tube arrangements

International Journal of Heat and Mass Transfer ◽

10.1016/j.ijheatmasstransfer.2021.120905 ◽

2021 ◽

Vol 168 ◽

pp. 120905

Author(s):

Wei Wang ◽

Yong Shuai ◽

Bingrui Li ◽

Bingxi Li ◽

Kwan-Soo Lee

Keyword(s):

Heat Transfer ◽

Heat Exchangers ◽

Heat Transfer Performance ◽

Transfer Performance ◽

Enhanced Heat Transfer

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Developments in Enhanced Heat Transfer Technology From a Petroleum Industry Perspective in 2012

Volume 2: Heat Transfer Enhancement for Practical Applications; Fire and Combustion; Multi-Phase Systems; Heat Transfer in Electronic Equipment; Low Temperature Heat Transfer; Computational Heat Transfer ◽

10.1115/ht2012-58301 ◽

2012 ◽

Cited By ~ 1

Author(s):

Matthew P. Rudy ◽

Thomas M. Rudy ◽

Himanshu M. Joshi ◽

Amar S. Wanni

Keyword(s):

Heat Transfer ◽

Heat Exchangers ◽

Petroleum Industry ◽

Current Paper ◽

Enhanced Heat Transfer ◽

The Past

Within the past 30 years, many Enhanced Heat Transfer (EHT) technologies have become available in a number of forms for application in heat exchangers. These technologies are used in various industries to widely different extents. In 1999, H. Joshi, T. Rudy, and A. Wanni, former Ph.D. students of Dr. Ralph L. Webb and specialists in the application of EHTs in the Petroleum Industry prepared a paper for the Journal of Enhanced Heat Transfer that reviewed the extent of use of EHT Technologies in the Petroleum Industry [1]. The current paper reviews how the application of EHT in the Petroleum Industry has changed in the last 14 years.

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Recent developments in applied thermal engineering: Process integration, heat exchangers, enhanced heat transfer, solar thermal energy, combustion and high temperature processes and thermal process modelling

Applied Thermal Engineering ◽

10.1016/j.applthermaleng.2016.06.183 ◽

2016 ◽

Vol 105 ◽

pp. 755-762 ◽

Cited By ~ 5

Author(s):

Zhi-Yong Liu ◽

Petar Sabev Varbanov ◽

Jiří Jaromír Klemeš ◽

Jun Yow Yong

Keyword(s):

Heat Transfer ◽

Heat Exchangers ◽

Thermal Process ◽

Process Integration ◽

Thermal Engineering ◽

Engineering Process ◽

Solar Thermal Energy ◽

Enhanced Heat Transfer ◽

High Temperature Processes ◽

Recent Developments

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Performance and Exergy Transfer Analysis of Heat Exchangers with Graphene Nanofluids in Seawater Source Marine Heat Pump System

Energies ◽

10.3390/en13071762 ◽

2020 ◽

Vol 13 (7) ◽

pp. 1762 ◽

Cited By ~ 3

Author(s):

Zhe Wang ◽

Fenghui Han ◽

Yulong Ji ◽

Wenhua Li

Keyword(s):

Heat Transfer ◽

Heat Exchanger ◽

Heat Pump ◽

Heat Exchangers ◽

Transfer Model ◽

Enhanced Heat Transfer ◽

Pump System ◽

Heat Pump System ◽

Tube Heat Exchanger ◽

Exergy Transfer

A marine seawater source heat pump is based on the relatively stable temperature of seawater, and uses it as the system’s cold and heat source to provide the ship with the necessary cold and heat energy. This technology is one of the important solutions to reduce ship energy consumption. Therefore, in this paper, the heat exchanger in the CO2 heat pump system with graphene nano-fluid refrigerant is experimentally studied, and the influence of related factors on its heat transfer enhancement performance is analyzed. First, the paper describes the transformation of the heat pump system experimental bench, the preparation of six different mass concentrations (0~1 wt.%) of graphene nanofluid and its thermophysical properties. Secondly, this paper defines graphene nanofluids as beneficiary fluids, the heat exchanger gains cold fluid heat exergy increase, and the consumption of hot fluid heat is heat exergy decrease. Based on the heat transfer efficiency and exergy efficiency of the heat exchanger, an exergy transfer model was established for a seawater source of tube heat exchanger. Finally, the article carried out a test of enhanced heat transfer of heat exchangers with different concentrations of graphene nanofluid refrigerants under simulated seawater constant temperature conditions and analyzed the test results using energy and an exergy transfer model. The results show that the enhanced heat transfer effect brought by the low concentration (0~0.1 wt.%) of graphene nanofluid is greater than the effect of its viscosity on the performance and has a good exergy transfer effectiveness. When the concentration of graphene nanofluid is too high, the resistance caused by the increase in viscosity will exceed the enhanced heat transfer gain brought by the nanofluid, which results in a significant decrease in the exergy transfer effectiveness.

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An Experimental Investigation of Convective Heat Transfer From Wire-On-Tube Heat Exchangers

Journal of Heat Transfer ◽

10.1115/1.2824231 ◽

1997 ◽

Vol 119 (2) ◽

pp. 348-356 ◽

Cited By ~ 19

Author(s):

J. L. Hoke ◽

A. M. Clausing ◽

T. D. Swofford

Keyword(s):

Heat Transfer ◽

Experimental Investigation ◽

Convective Heat Transfer ◽

Convective Heat ◽

Heat Exchangers ◽

Steel Wire ◽

Convective Heat Transfer Coefficient ◽

Wire Diameter ◽

Forced Flow ◽

Geometrical Parameters

An experimental investigation of the air-side convective heat transfer from wire-on-tube heat exchangers is described. The study is motivated by the desire to predict the performance, in a forced flow, of the steel wire-on-tube condensers used in most refrigerators. Previous investigations of wire-on-tube heat exchangers in a forced flow have not been reported in the literature. The many geometrical parameters (wire diameter, tube diameter, wire pitch, tube pitch, etc.), the complex conductive paths in the heat exchanger, and the importance of buoyant forces in a portion of the velocity regime of interest make the study a formidable one. A key to the successful correlation of the experimental results is a definition of the convective heat transfer coefficient, hw, that accounts for the temperature gradients in the wires as well as the vast difference in the two key characteristic lengths—the tube and wire diameters. Although this definition results in the need to solve a transcendental equation in order to obtain hw from the experimental data, the use of the resulting empirical correlation is straightforward. The complex influence of the mixed convection regime on the heat transfer from wire-on-tube heat exchangers is shown, as well as the effects of air velocity and the angle of attack. The study covers a velocity range of 0 to 2 m/s (the Reynolds number based on wire diameter extends to 200) and angles of attack varying from 0 deg (horizontal coils) to ±90 deg. Heat transfer data from seven different wire-on-tube heat exchangers are correlated so that 95 percent of the data below a Richardson number of 0.004, based on the wire diameter, lie within ±16.7 percent of the proposed correlation.

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Experimental Investigation of Enhanced Heat Transfer and Pressure Drop in a Solar Air Heater Duct With Discretized Broken V-Rib Roughness

Journal of Solar Energy Engineering ◽

10.1115/1.4028071 ◽

2014 ◽

Vol 137 (2) ◽

Cited By ~ 12

Author(s):

Anil Kumar Patil ◽

J. S. Saini ◽

Krishna Kumar

Keyword(s):

Heat Transfer ◽

Experimental Investigation ◽

Geometrical Parameters ◽

Solar Air Heater ◽

Enhanced Heat Transfer ◽

Transfer Rates ◽

Air Heater ◽

Effective Efficiency ◽

Flow Through ◽

Considerable Enhancement

The present study examines the augmentation in heat transfer and friction in a flow through solar air heater duct with discretized broken V-rib roughness. The experimental outcomes pertaining to Reynolds number from 3000 to 17,000, relative gap position (s′/s) from 0.2 to 0.8, relative staggered rib position (p′/p) from 0.2 to 0.8 have been presented and discussed. Discretized broken V-rib roughness brought out considerable enhancement in heat transfer rates over V-rib roughness and smooth duct. Effective efficiency of discretized broken V-rib roughened solar air heater is estimated and geometrical parameters of roughness are optimized with regard to temperature rise parameter and insolation.

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