scholarly journals Overview of the innovative heat exchangers technologies

2020 ◽  
Vol XXIII (2) ◽  
pp. 32-36
Author(s):  
Avram Elena Rita
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Heat Exchangers ◽  
Micro Channels ◽  
Flow Processes ◽  
Military Applications ◽  
Flow Through ◽  
Heat And Fluid Flow ◽  
Resistance To Heat ◽  
Similitude Theory

The current paper analyzed the new trends and challenges in heat exchanger technologies. The progress of the studies on mini and micro devices used in industry are presented. Particular attention is paid to the heat exchangers used in marine and chemical industries where the resistance to heat transfer increases due to the fouling or scaling. In the industry, there are very important the reduction in the size of devices, and the micro heat exchangers, due to its variety of advantages offered, are well recognized for their higher performance. The applications of them are ranging from process control to military applications. New engineering approaches for modeling the heat and fluid flow processes in micro heat exchangers are analyzed in the present paper. One of these is based on the dimensional analysis and principles of similitude theory that allow the modeling of microscale systems using a physical system at the mini scale. There are identified constant relationships between dimensions permitting the analysis of the fluid flow through micro channels.

Numerical Simulations of Heat and Fluid Flow in Grooved Channels With Curved Vanes

2003 ◽  
Author(s):  
Matthew McGarry ◽  
Antonio Campo ◽  
Darren L. Hitt
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Fluid Flow ◽  
Heat Exchangers ◽  
System Performance ◽  
Vortex Formation ◽  
Electronics Cooling ◽  
Reynolds Numbers ◽  
Transfer Enhancement ◽  
Heat And Fluid Flow

The use of vanes in grooved channels for heat transfer enhancement has received more attention in the recent years due to applications in heat exchangers and electronics cooling. The current work focuses on characterizing the vortex formation around heated elements in grooved channels with curved vanes. A computational model is developed to examine the effect that the vortices have on heat transfer and system performance for a range of Reynolds numbers of 100 to 800. These vortices explain the previously observed characteristics in system performance for geometries with the use of curved vanes. At a Reynolds number of 400 these vortices inhibit heat transfer and increase pressure drop in the channel, resulting in significant decreases in system performance.

Comparison of 30 Boiling and Condensation Correlations for Two-Phase Flows in Compact Plate-Fin Heat Exchangers

2017 ◽  
Author(s):  
Wenhai Li ◽  
Ken Alabi ◽  
Foluso Ladeinde
Keyword(s):  
Heat Transfer ◽  
Heat Exchangers ◽  
Flow Boiling ◽  
Transfer Coefficients ◽  
Two Phase Flows ◽  
Two Phase ◽  
Heat Transfer Coefficients ◽  
Heat Exchanger Design ◽  
Micro Channels ◽  
Vertical Tubes

Over the years, empirical correlations have been developed for predicting saturated flow boiling [1–15] and condensation [16–30] heat transfer coefficients inside horizontal/vertical tubes or micro-channels. In the present work, we have examined 30 of these models, and modified many of them for use in compact plate-fin heat exchangers. However, the various correlations, which have been developed for pipes and ducts, have been modified in our work to make them applicable to extended fin surfaces. The various correlations have been used in a low-order, one-dimensional, finite-volume type numerical integration of the flow and heat transfer equations in heat exchangers. The NIST’s REFPROP database [31] is used to account for the large variations in the fluid thermo-physical properties during phase change. The numerical results are compared with Yara’s experimental data [32]. The validity of the various boiling and condensation models for a real plate-fin heat exchanger design is discussed. The results show that some of the modified boiling and condensation correlations can provide acceptable prediction of heat transfer coefficient for two-phase flows in compact plate-fin heat exchangers.

scholarly journals Chemical Entropy Generation and MHD Effects on the Unsteady Heat and Fluid Flow through a Porous Medium

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Gamal M. Abdel-Rahman Rashed
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Fluid Flow ◽  
Entropy Generation ◽  
Lewis Number ◽  
Heat Transfer Fluid ◽  
Governing Equations ◽  
Flow Through ◽  
Heat And Fluid Flow ◽  
Chemical Reaction Parameter

Chemical entropy generation and magnetohydrodynamic effects on the unsteady heat and fluid flow through a porous medium have been numerically investigated. The entropy generation due to the use of a magnetic field and porous medium effects on heat transfer, fluid friction, and mass transfer have been analyzed numerically. Using a similarity transformation, the governing equations of continuity, momentum, and energy and concentration equations, of nonlinear system, were reduced to a set of ordinary differential equations and solved numerically. The effects of unsteadiness parameter, magnetic field parameter, porosity parameter, heat generation/absorption parameter, Lewis number, chemical reaction parameter, and Brinkman number parameter on the velocity, the temperature, the concentration, and the entropy generation rates profiles were investigated and the results were presented graphically.

Analysis on unsteady heat transfer and fluid flow through sensible heat storage system

2021 ◽  
Author(s):  
Sasikumar C ◽  
Sundaresan R ◽  
Rajaganapthy C ◽  
Nagaraj M ◽  
Radha Krishnan Beemaraj
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Heat Storage ◽  
Storage System ◽  
Sensible Heat ◽  
Unsteady Heat Transfer ◽  
Flow Through
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