What dominates heat transfer performance of hybrid nanofluid in single pass shell and tube heat exchanger?

2019 ◽  
Vol 30 (12) ◽  
pp. 3107-3117 ◽  
Author(s):  
S. Anitha ◽  
Tiju Thomas ◽  
V. Parthiban ◽  
M. Pichumani
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Transfer Performance ◽  
Hybrid Nanofluid ◽  
Transfer Performance ◽  
Tube Heat Exchanger ◽  
Single Pass ◽  
Shell And Tube

Comparative CFD Analysis of Maldistribution in a Shell and Tube Heat Exchanger With Conical and Cylindrical Headers

2010 ◽  
Author(s):  
Rohitha Paruchuri ◽  
T. S. Ravigururajan ◽  
Arun Muley
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Transfer Performance ◽  
Static Pressure ◽  
Flow Distribution ◽  
Transfer Performance ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
Improved Performance ◽  
Flow Maldistribution

The analysis of flow maldistribution in a shell and tube heat exchanger is presented. The flow field within the headers was obtained through numerical solution of conservation equations of mass and momentum in addition to the equations of the turbulence model. The flow maldistribution inside the header was a 3-D numerical simulation with the help of commercial software To increase the performance of the heat exchanger, flow maldistribution among the tubes should be minimized.. Flow maldistribution in the header affects the heat transfer performance. The effects of the pressure drop and velocity distribution in the headers were analyzed, as it effects the heat transfer performance. The study showed that by changing the header geometry, the maldistribution can be reduced leading to improved performance. Two types of headers were considered with varying header length and inlet flow velocities from 0.8373mm/sec to 2.344mm/sec are considered. The uniformity of flow distribution improved with increasing header length, whereas it decreased with increasing flow rate. As the header length increased to 1500mm the flow maldistribution decreased and the static pressure was almost equal for all the tubes in case of a conical header. The results show that conical header minimizes flow maldistribution compared to a cylindrical header.

Effects of Baffle Overlap Proportion on Shell-Side Performance of Shell and Tube Heat Exchanger With Helical Baffles

2013 ◽  
Author(s):  
Bin Gao ◽  
Qincheng Bi ◽  
Zesen Nie
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Flow Rate ◽  
Heat Transfer Performance ◽  
Transfer Performance ◽  
Shell Side ◽  
Tube Heat Exchanger ◽  
Flow And Heat Transfer ◽  
Shell And Tube ◽  
Side Flow

Different overlap configurations of discontinuous helical baffles affect the flow pattern of the shell-side fluid directly, and thus there is a significant impact on the flow and heat transfer characteristics of the shell-side fluid. In the present paper, experiments were carried out to study the impact of baffle overlap proportion on the shell-side flow and heat transfer performance of the shell-and-tube heat exchanger with helical baffles (STHEHB). Two different shell-side friction factors, the friction factor per helical pitch (fs,1B) and the friction factor per tube length (fs,1m), were defined based on different reference lengths. The results showed that, since the baffle overlap proportion leads to different helical pitch as well as flow fields in shell side, opposite conclusions are obtained by choosing different reference length. Based on the same Reynolds number, the shell-side Nusselt number of the STHEHB with 10% baffle overlap is higher than that with 50% baffle overlap. The reason is that the larger baffle overlap proportion produces more serious leak flows and weakens the heat transfer in shell side. The comparison of heat transfer coefficient per unit pressure drop versus shell-side flow rate showed that the STHEHB with smaller baffle overlap proportion has better comprehensive heat transfer performance, but the difference between the two decreases gradually with the increase of the flow rate.

scholarly journals Effect of Magnetic Nanofluids on the Performance of a Fin-Tube Heat Exchanger

2021 ◽  
Vol 11 (19) ◽  
pp. 9261
Author(s):  
Yun-Seok Choi ◽  
Youn-Jea Kim
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Magnetic Fields ◽  
Heat Transfer Performance ◽  
Permanent Magnets ◽  
Convective Heat Transfer Coefficient ◽  
Transfer Performance ◽  
Tube Heat Exchanger ◽  
Improve Heat Transfer ◽  
Fin Tube

As electrical devices become smaller, it is essential to maintain operating temperature for safety and durability. Therefore, there are efforts to improve heat transfer performance under various conditions, such as using extended surfaces and nanofluids. Among them, cooling methods using ferrofluid are drawing the attention of many researchers. This fluid can control the movement of the fluid in magnetic fields. In this study, the heat transfer performance of a fin-tube heat exchanger, using ferrofluid as a coolant, was analyzed when external magnetic fields were applied. Permanent magnets were placed outside the heat exchanger. When the magnetic fields were applied, a change in the thermal boundary layer was observed. It also formed vortexes, which affected the formation of flow patterns. The vortex causes energy exchanges in the flow field, activating thermal diffusion and improving heat transfer. A numerical analysis was used to observe the cooling performance of heat exchangers, as the strength and number of the external magnetic fields were varying. VGs (vortex generators) were also installed to create vortex fields. A convective heat transfer coefficient was calculated to determine the heat transfer rate. In addition, the comparative analysis was performed with graphical results using contours of temperature and velocity.

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