Advances in Application of Numerical Simulation of Fluid Flow in Tube Bundle Heat Exchangers

2002 ◽  
Author(s):  
Michael Fischer ◽  
Klaus Strohmeier
Keyword(s):  
Numerical Simulation ◽  
Fluid Flow ◽  
Heat Exchangers ◽  
Tube Bundle

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 Numerical simulation of unsteady flow of a viscous incompressible liquid in flat channels of arbitrary shape of heat exchangers

2020 ◽  
Vol 34 ◽  
pp. 41-55
Author(s):  
Y. Chоvniuk ◽  
V. Kravchuk ◽  
A. Moskvitina ◽  
I. Pefteva
Keyword(s):  
Numerical Simulation ◽  
Fluid Flow ◽  
Unsteady Flow ◽  
Heat Exchangers ◽  
Arbitrary Shape ◽  
Stokes Equations ◽  
Navier Stokes ◽  
Computational Domain ◽  
Two Dimensional ◽  
Navier Stokes Equations

Reasonable development and creation of any device in which there is an interaction between the fluid flow and the elements of the flow parts (for example, heat exchangers, transport and power machines, main pipelines), is impossible without detailed information about the characteristics of the flow, about the forces on the surfaces that are around, about vibroacoustic phenomena, etc. Among the various methods of obtaining information about the characteristics of the flow, about the forces on surfaces that are flown around, about vibroacoustic phenomena, an important role is played by theoretical methods that rely on the equation of hydrodynamics and numerous ways to solve them. In this case, the main efforts are aimed at solving the system of Navier-Stokes equations. In this paper, a general method is described for the numerical solution of the problem of unsteady flow of a viscous incompressible fluid in flat channels of an arbitrary shape of heat exchangers. An effective solution to the problem is achieved by using adaptive networks. The mathematical model of the flow is based on the two-dimensional Navier-Stokes equations in the variables "flow function - vortex" and the Poissonequation for pressure, which are solved on the basis of the finite-difference method. A numerical simulation of the fluid flow in a flat curvilinear elbow is carried out at the Reynolds number Re = 1000. This form reflects the most characteristic features of the flow paths of various hydraulic machines, heat exchangers, hydraulic and pipeline systems. The presentation of the numerical results was carried out on the basis of the VISSIM graphic processing package. One of the main problems (difficulties) in the numerical solution of problems of mathematical physics is the representation of boundary conditions for regions of arbitrary shape. The implementation of various artificial methods that are now used in the approximation of both the curvilinear boundaries themselves and the boundary conditions on them can lead to significant losses in the accuracy of the solution. This is especially evident in problems in which solutions in the boundary region have maximum gradients. An effective method for solving this problem is the use of adapted grids for the computational domain. The essence of this method lies in the fact that such a coordinate system, not necessarily orthogonal, is found in which the boundary lines (surfaces) of the region coincide with the coordinate lines (surfaces). In the flat case, the computational domain is transformed into a rectangular one, and the limit curve is displayed on the sides of the rectangle. In practice, the problem of constructing an adapted mesh is reduced to finding functions that describe the mappings of the canonical (rectangular) region onto the region for which the problem was originally formulated, that is, for the two-dimensional case, the functions x (ξ, η), y (ξ, η) are determined.

Effects of Tube Stiffness and Tubesheet Thickness on the Thermal Stress of the Tubes and Tubesheet

2011 ◽  
Vol 314-316 ◽  
pp. 1552-1555 ◽  
Author(s):  
Hui Fang Li ◽  
Cai Fu Qian ◽  
Xiao Dong Yu
Keyword(s):  
Numerical Simulation ◽  
Thermal Stress ◽  
Heat Exchanger ◽  
Temperature Difference ◽  
Heat Exchangers ◽  
Tube Bundle ◽  
Large Temperature ◽  
Shell Side ◽  
Large Temperature Difference ◽  
Strength Failure

In this paper, numerical simulation was carried out for the tube bundle of a float-head heat exchanger with concentration on the effects of tube stiffness and tubesheet thickness on the thermal stress of the tubes and tubesheet. It is found that decreasing the tube stiffness by using corrugated tubes can reduce the axial thermal stress at the tubes and, thus, decrease the possibility of strength failure of the connection between the tubes and tubesheet. Decreasing the tubesheet thickness can reduce the thermal stress at the tubesheet, which is meaningful for the heat exchangers with large temperature difference between the shell-side fluid and tube-side fluid and under small pressures.

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