Intensification of Heat Transfer in a Double Tube Heat Exchanger with Nano-Fluids and Trapezoidal Cut Twisted Tape - A Numerical Study

2019 ◽  
Vol 11 (3) ◽  
Author(s):  
C. Gnanavel ◽  
R. Saravanan ◽  
M. Chandrasekaran
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Numerical Study ◽  
Beryllium Oxide ◽  
Nano Particles ◽  
Twisted Tape ◽  
Tube Heat Exchanger ◽  
Passive Technique ◽  
Energy Equations ◽  
Nano Fluids

The heat transfer enhancement is normally demanded in industries for heating, cooling and evaporation in the equipment’s like air conditioning, radiators and refrigerators etc. The passive, active or combination of them usually employed for intensification of heat transfer in such heat exchangers. In this study, we focus on an innovative passive technique. The dual approach is to increase the conductivity of the suspended nano-particles such as titanium dioxide, beryllium oxide or beryllia, zinc oxide and copper oxide in the water. The flow resistance is offered by inserting the twisted tape with trapezoidal cut. The objective of the numerical study is to investigate the thermal and flow fields by utilizing various types of nano-fluids with and without twisted tape in the double tube heat exchanger. The finite volume method is employed to solve the continuity, momentum and energy equations.

Heat Transfer Effect of CNT and Ethylene Glycol Based Nano-Fluid in Twisted Tape Heat Exchanger with Balls

2020 ◽  
Vol 12 (4) ◽  
Author(s):  
R. Saravanan ◽  
M. Karuppasamy ◽  
M. Chandrasekaran ◽  
V. Muthuraman
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Ethylene Glycol ◽  
Heat Exchangers ◽  
Twisted Tape ◽  
Heat Transfer Fluids ◽  
Nano Fluid ◽  
Carbon Nano Tubes ◽  
Heat Transfer Improvement ◽  
Nano Fluids

Heat transfer improvement is the main parameter in a heat exchanging equipment. Few methods to increase the coefficient of heat transfer is by creating the turbulence in heat exchanging elements and changing the heat transfer fluids. For current analysis of tube heat exchangers, tape inserts containing balls are implemented with nano-fluids in Carbon Nano Tubes (CNT) and ethylene glycol. 3D modelling and simulation of twisted tape heat exchanger with balls were carried out using Solidworks and ANSYS Workbench. Heat transfer rate, friction factor, temperature difference in the heat exchangers, Reynolds number and Nusselt number variations are assessed in this work.

Thermal Performance Enhancement of an Industrial Shell and Tube Heat Exchanger

2015 ◽  
Author(s):  
Fadi A. Ghaith ◽  
Ahmed S. Izhar
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Transfer Coefficient ◽  
Thermal Performance ◽  
Numerical Study ◽  
Thermal Design ◽  
Shell Side ◽  
Tube Heat Exchanger ◽  
Shell And Tube

This paper aims to enhance the thermal performance of an industrial shell-and-tube heat exchanger utilized for the purpose of cooling raw natural gas by means of mixture of Sales gas. The main objective of this work is to provide an optimum and reliable thermal design of a single-shelled finned tubes heat exchanger to replace the existing two- shell and tube heat exchanger due to the space limitations in the plant. A comprehensive thermal model was developed using the effectiveness-NTU method. The shell-side and tube-side overall heat transfer coefficient were determined using Bell-Delaware method and Dittus-Boelter correlation, respectively. The obtained results showed that the required area to provide a thermal duty of 1.4 MW is about 1132 m2 with tube-side and shell-side heat transfer coefficients of 950 W/m2K and 495 W/m2K, respectively. In order to verify the obtained results generated from the mathematical model, a numerical study was carried out using HTRI software which showed a good match in terms of the heat transfer area and the tube-side heat transfer coefficient.

Numerical Study of Shellside Performance of Heat Transfer and Flow Resistance for Heat Exchanger with Trefoil-Hole Baffles

2012 ◽  
Vol 557-559 ◽  
pp. 2141-2146
Author(s):  
Yong Hua You ◽  
Ai Wu Fan ◽  
Chen Chen ◽  
Shun Li Fang ◽  
Shi Ping Jin ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Heat Exchanger ◽  
Heat Transfer Rate ◽  
Pressure Loss ◽  
Transfer Rate ◽  
Numerical Study ◽  
Shell Side ◽  
Tube Heat Exchanger

Trefoil-hole baffles have good thermo-hydraulic performances as the support of heat pipes, however the published research paper is relatively limited. The present paper investigates the shellside thermo-hydraulic characteristics of shell-and-tube heat exchanger with trefoil-hole baffles (THB-STHX) under turbulent flow region, and the variations of shellside Nusselt number, pressure loss and overall thermo-hydraulic performance (PEC) with Reynolds number are obtained for baffles of varied pitch with the numerical method. CFD results demonstrate that the trefoil-hole baffle could enhance the heat transfer rate of shell side effectively, and the maximal average Nusselt number is augmented by ～2.3 times that of no baffle, while average pressure loss increases by ～9.6 times. The PEC value of shell side lies in the range of 16.3 and 73.8 kPa-1, and drops with the increment of Reynolds number and the decrement of baffle pitch, which indicates that the heat exchanger with trefoil-hole baffles of larger pitch could generate better overall performance at low Reynolds number. Moreover, the contours of velocity, turbulent intensity and temperature are presented for discussions. It is found that shellside high-speed jet, intensive recirculation flow and high turbulence level could enhance the heat transfer rate effectively. Besides good performance, THB-STHXs are easily manufactured, thus promise widely applied in various industries.

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