Mathematical modelling of tube heat exchangers with complex flow arrangement

2011 ◽  
Vol 32 (1) ◽  
pp. 7-19 ◽  
Author(s):  
Dawid Taler ◽  
Marcin Trojan ◽  
Jan Taler
Keyword(s):  
Mathematical Modelling ◽  
Heat Exchangers ◽  
Initial Conditions ◽  
Cross Flow ◽  
Steam Superheater ◽  
Transient Temperature ◽  
Complex Flow ◽  
Flow Tube ◽  
Calculation Results ◽  
Volume Method

Mathematical modelling of tube heat exchangers with complex flow arrangement General principles of mathematical modelling of transient heat transfer in cross-flow tube heat exchangers with complex flow arrangements which allow a simulation of multipass heat exchangers with many tube rows are presented. First, a system of differential equations for the transient temperature of both fluids and the tube wall with appropriate boundary and initial conditions is formulated. Two methods for modelling heat exchangers are developed using the finite difference method and finite volume method. A numerical model of multipass steam superheater with twelve passes is presented. The calculation results are compared with the experimental data.

Mathematical Modeling of Cross-Flow Tube Heat Exchangers With a Complex Flow Arrangement

2014 ◽  
Vol 35 (14-15) ◽  
pp. 1334-1343 ◽  
Author(s):  
Dawid Taler ◽  
Marcin Trojan ◽  
Jan M. Taler
Keyword(s):  
Mathematical Modeling ◽  
Heat Exchangers ◽  
Cross Flow ◽  
Complex Flow ◽  
Flow Tube

Thermal Performance of Multipass Parallel and Counter-Cross-Flow Heat Exchangers

2006 ◽  
Vol 129 (3) ◽  
pp. 282-290 ◽  
Author(s):  
Luben Cabezas-Gómez ◽  
Hélio Aparecido Navarro ◽  
José Maria Saiz-Jabardo
Keyword(s):  
Heat Exchanger ◽  
Thermal Performance ◽  
Heat Exchangers ◽  
Experimental Studies ◽  
Cross Flow ◽  
Numerical Procedure ◽  
Complex Flow ◽  
Flow Heat ◽  
Small Elements ◽  
Effectiveness Data

A thorough study of the thermal performance of multipass parallel cross-flow and counter-cross-flow heat exchangers has been carried out by applying a new numerical procedure. According to this procedure, the heat exchanger is discretized into small elements following the tube-side fluid circuits. Each element is itself a one-pass mixed-unmixed cross-flow heat exchanger. Simulated results have been validated through comparisons to results from analytical solutions for one- to four-pass, parallel cross-flow and counter-cross-flow arrangements. Very accurate results have been obtained over wide ranges of NTU (number of transfer units) and C* (heat capacity rate ratio) values. New effectiveness data for the aforementioned configurations and a higher number of tube passes is presented along with data for a complex flow configuration proposed elsewhere. The proposed procedure constitutes a useful research tool both for theoretical and experimental studies of cross-flow heat exchangers thermal performance.

scholarly journals New calculation method for tube cross-flow heat exchangers

2021 ◽  
Vol 323 ◽  
pp. 00032
Author(s):  
Katarzyna Węglarz ◽  
Dawid Taler ◽  
Jan Taler ◽  
Mateusz Marcinkowski
Keyword(s):  
Heat Exchangers ◽  
Cross Flow ◽  
Analytical Models ◽  
Temperature Dependent ◽  
Flow Tube ◽  
Thermal Calculations ◽  
Analytical Formulas ◽  
Flow Heat ◽  
Control Volumes ◽  
Good Agreement

A new method for thermal calculations of the cross-flow tube heat exchangers was proposed. The temperature of both fluids and the wall temperature are determined. The heat exchanger is divided into control volumes, in which outlet fluid temperatures are calculated by closed analytical formulas. Two examples of the application of the method for the calculation of two-pass cross-co-current and cross-countercurrent superheaters were presented. An exact analytical model was also developed for both superheaters to estimate the accuracy of the proposed method. The results of the superheater calculations using the developed method are in good agreement with the results obtained by the exact analytical models. The proposed method can be used to calculate heat exchangers with a complicated flow system in which the physical properties of fluids are temperature-dependent.

A Comparative Study of Different Grid Models for an Oil Spill Under Water

2016 ◽  
Author(s):  
Meirong Jiang ◽  
Zhigang Li ◽  
Jianxing Yu ◽  
Hanjun Yin ◽  
Ying Jiang
Keyword(s):  
Comparative Study ◽  
Oil Spill ◽  
Ocean Current ◽  
Volume Of Fluid Method ◽  
Complex Flow ◽  
Structured Grid ◽  
Calculation Results ◽  
Dense Grid ◽  
Volume Method ◽  
Simulated Time

Due to the serious results of an oil leakage of a subsea pipeline, the prediction of the numerical simulation must be modeled accurately and quickly. To select a proper numerical model to simulate the complex flow, a comparative study with different grid models is carried out. A two dimensional oil diffusion model under the ocean current is established using the finite volume method. Based on the structured grid, the volume of fluid method is employed to track the interface of the multiphase flow. Two kinds of grid models, the sparse and the dense grid, are simulated under the same conditions. Three cases are selected from the typical experiments in Fan (1967). The available experimental data in the oil spill test of Fan (1967) are employed as a criterion for the comparison between different grid models. According to the calculation results, a comparative analysis of the oil diffusing form, the arriving time to the surface, and the lateral drifting distance is studied between the two grid models, respectively. The surface diffusion range and the simulated time are also introduced to do the comparison for the grid density.

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