The combined effects of wall longitudinal heat conduction and inlet fluid flow maldistribution in crossflow plate-fin heat exchangers

2000 ◽  
Vol 36 (3) ◽  
pp. 247-256 ◽  
Author(s):  
Ch. Ranganayakulu ◽  
K. N. Seetharamu
Keyword(s):  
Fluid Flow ◽  
Heat Conduction ◽  
Heat Exchangers ◽  
Combined Effects ◽  
Flow Maldistribution

Numerical simulation of flow distribution in the header of plate-fin heat exchanger

2020 ◽  
Vol 34 (14n16) ◽  
pp. 2040111
Author(s):  
Shu-Ling Tian ◽  
Ying-Ying Shen ◽  
Yao Li ◽  
Hai-Bo Wang ◽  
Sheryar Muhammad ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Fluid Flow ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Optimization Design ◽  
High Efficiency ◽  
Flow Distribution ◽  
Optimal Number ◽  
Compact Structure ◽  
Flow Maldistribution

Plate-fin heat exchangers are widely used in industry at present due to their compact structure and high efficiency. However, there is a problem of flow maldistribution, resulting in poor performance of heat exchangers. The influence of the header configuration on fluid flow distribution is studied by using CFD software FLUENT. The numerical results show that the fluid flow inside the header is seriously uneven. The reliability of the numerical simulation is validated against the published results. They are found to be basically consistent within considerable error. The optimal number of the punch baffle is investigated. Various header configuration with different opening ratios have been studied under the same boundary conditions. The gross flow maldistribution parameter (S) is used to evaluate flow nonuniformity, and the flow maldistribution parameters of different schemes under different Reynolds numbers are listed and compared. The optimal header with minimum flow maldistribution parameter is obtained through the performance analysis of headers. It is found that the flow maldistribution of the improved header is significantly smaller compared with the conventional header. Hence, the efficiency of the heat exchanger is effectively enhanced. The conclusion provides a reference for the optimization design of plate-fin heat exchanger.

scholarly journals Analysis Exploring the Uniformity of Flow Distribution in Multi-Channels for the Application of Printed Circuit Heat Exchangers

Symmetry ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 314 ◽  
Author(s):  
Hanbing Ke ◽  
Yuansheng Lin ◽  
Zhiwu Ke ◽  
Qi Xiao ◽  
Zhiguo Wei ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Heat Exchangers ◽  
Electronic Device ◽  
Numerical Models ◽  
Sudden Change ◽  
Flow Distribution ◽  
Outer Radius ◽  
Air Separation ◽  
Printed Circuit ◽  
Flow Maldistribution

The maldistribution of fluid flow through multi-channels is a critical issue encountered in many areas, such as multi-channel heat exchangers, electronic device cooling, refrigeration and cryogenic devices, air separation and the petrochemical industry. In this paper, the uniformity of flow distribution in a printed circuit heat exchanger (PCHE) is investigated. The flow distribution and resistance characteristics of a PCHE plate are studied with numerical models under different flow distribution cases. The results show that the sudden change in the angle of the fluid at the inlet of the channel can be greatly reduced by using a spreader plate with an equal inner and outer radius. The flow separation of the fluid at the inlet of the channel can also be weakened and the imbalance of flow distribution in the channel can be reduced. Therefore, the flow uniformity can be improved and the pressure loss between the inlet and outlet of PCHEs can be reduced. The flow maldistribution in each PCHE channel can be reduced to ± 0.2%, and the average flow maldistribution in all PCHE channels can be reduced to less than 5% when the number of manifolds reaches nine. The numerical simulation of fluid flow distribution can provide guidance for the subsequent research and the design and development of multi-channel heat exchangers. In summary, the symmetry of the fluid flow in multi-channels for PCHE was analyzed in this work. This work presents the frequently encountered problem of maldistribution of fluid flow in engineering, and the performance promotion leads to symmetrical aspects in both the structure and the physical process.

Experimental Investigation on Fluid Flow Maldistribution in Plate-Fin Heat Exchangers

2003 ◽  
Vol 24 (4) ◽  
pp. 25-31 ◽  
Author(s):  
Jiao Anjun ◽  
Li Yanzhong ◽  
Chen ChunZheng ◽  
Zhang Rui
Keyword(s):  
Experimental Investigation ◽  
Fluid Flow ◽  
Heat Exchangers ◽  
Flow Maldistribution

A Correlation for the Heat Conduction Effects in Counterflow Rotary Regenerative Heat Exchangers

1993 ◽  
Vol 115 (4) ◽  
pp. 287-290 ◽  
Author(s):  
C. M. Shen ◽  
W. M. Worek
Keyword(s):  
Heat Capacity ◽  
Fluid Flow ◽  
Heat Conduction ◽  
Heat Exchangers ◽  
Flow Direction ◽  
Performance Comparison ◽  
Regenerative Heat ◽  
Numerical Predictions ◽  
The Matrix ◽  
Biot Numbers

Equations that predict the dependence of regenerator effectiveness on heat conduction in the matrix both parallel to and perpendicular to the fluid flow are derived from numerical simulations. The equations developed use Biot numbers parallel to the direction of fluid flow (Bix) and perpendicular to the fluid flow direction (Biy), the ratio of heat capacity rates (C*), the heat capacity rate ratio (C*Γ), and the overall number of transfer units (NTUo) to characterize the regenerator performance. Comparison of numerical predictions with those obtained using the equations developed in this paper show excellent agreement. These equations enable designers to accurately account for two-dimensional conduction effects when regenerators are designed.

Numerical analysis of compact plate-fin heat exchangers for aerospace applications

2018 ◽  
Vol 28 (2) ◽  
pp. 395-412 ◽  
Author(s):  
Ranganayakulu Chennu
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Heat Conduction ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Cross Flow ◽  
Design Data ◽  
Content Type ◽  
Compact Heat Exchangers ◽  
Performance Deterioration

Purpose The purpose of this study is to find the thermo-hydraulic performances of compact heat exchangers (CHE’s), which are strongly depending upon the prediction of performance of various types of heat transfer surfaces such as offset strip fins, wavy fins, rectangular fins, triangular fins, triangular and rectangular perforated fins in terms of Colburn “j” and Fanning friction “f” factors. Design/methodology/approach Numerical methods play a major role for analysis of compact plate-fin heat exchangers, which are cost-effective and fast. This paper presents the on-going research and work carried out earlier for single-phase steady-state heat transfer and pressure drop analysis on CHE passages and fins. An analysis of a cross-flow plate-fin compact heat exchanger, accounting for the individual effects of two-dimensional longitudinal heat conduction through the exchanger wall, inlet fluid flow maldistribution and inlet temperature non-uniformity are carried out using a Finite Element Method (FEM). Findings The performance deterioration of high-efficiency cross-flow plate-fin compact heat exchangers have been reviewed with the combined effects of wall longitudinal heat conduction and inlet fluid flow/temperature non-uniformity using a dedicated FEM analysis. It is found that the performance deterioration is quite significant in some typical applications due to the effects of wall longitudinal heat conduction and inlet fluid flow non-uniformity on cross-flow plate-fin heat exchangers. A Computational Fluid Dynamics (CFD) program FLUENT has been used to predict the design data in terms of “j” and “f” factors for plate-fin heat exchanger fins. The suitable design data are generated using CFD analysis covering the laminar, transition and turbulent flow regimes for various types of fins. Originality/value The correlations for the friction factor “f” and Colburn factor “j” have been found to be good. The correlations can be used by the heat exchanger designers and can reduce the number of tests and modification of the prototype to a minimum for similar applications and types of fins.

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