A General Expression for the Determination of the Log Mean Temperature Correction Factor for Shell and Tube Heat Exchangers

2003 ◽  
Vol 125 (3) ◽  
pp. 527-530 ◽  
Author(s):  
Ahmad Fakheri
Keyword(s):  
Heat Exchanger ◽  
Correction Factor ◽  
Heat Exchangers ◽  
Direct Determination ◽  
Temperature Correction ◽  
Tube Heat Exchanger ◽  
Mean Temperature ◽  
Shell And Tube ◽  
Graphical Presentation

This paper presents a single closed form algebraic equation for the determination of the Log Mean Temperature Difference correction factor F for shell and tube heat exchangers having N shell passes and 2M tube passes per shell. The equation and its graphical presentation generalize the traditional equations and charts used for the determination of F. The equation presented is also useful in design, analysis and optimization of multi shell and tube heat exchanger, particularly for direct determination of the number of shells.

Deflections of A Multipass Shell-and-Tube Heat Exchanger Bolted Joint Subjected to Nonaxisymmetric Thermal Loading

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Natalia Petrova ◽  
Abdel-Hakim Bouzid
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Thermal Loading ◽  
Cocurrent Flow ◽  
Finite Element Models ◽  
Bolted Joint ◽  
Tube Heat Exchanger ◽  
Specific Geometry ◽  
Shell And Tube

Despite the fact that multipass shell-and-tube heat exchangers operating at high temperature are subject to frequent problems related to flange sealing, there is neither detailed explanations for the reasons of the failures nor an adequate solution to this problem. Specific geometry of multipass heat exchangers and the temperature difference between the inlet and the outlet fluids is responsible for the existence of a thermal circumferential gradient at the shell-to-channel bolted joint. However, existing flange design methods do not address nonaxisymmetrical temperature loading of the flanged joint assembly. The circumferential thermal gradient, as the cause of frequent failures to seal the flanged joints, is ignored. This paper outlines the analytical modeling of a flanged joint with a tube sheet of a multipass heat exchanger subjected to a nonaxisymmetrical thermal loading. A shell-and-tube heat exchanger of 51 in. diameter with cocurrent flow was used for analysis. The main steps of the theoretical analysis used for the determination of the circumferential temperature profiles and the thermal expansion displacements and distortions of the bolted joint components are given. The results from the proposed analytical model are compared with those obtained from finite element models.

Numerical Determination of the LMTD Correction Factor for Shell-and-Tube 1-2 Heat Exchangers

2015 ◽  
Vol 789-790 ◽  
pp. 457-461
Author(s):  
Luiz Gustavo Monteiro Guimarães ◽  
Matheus dos Santos Guzella ◽  
Luben Cabezas-Gómez ◽  
Flávio Neves Teixeira
Keyword(s):  
Analytical Solution ◽  
Correction Factor ◽  
Heat Exchangers ◽  
Numerical Determination ◽  
Direct Computation ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
New Perspective ◽  
The One

This paper outlines a novel numerical methodology to compute the LMTD correction factor for a shell-and-tube heat exchangers. Although the presented methodology can be extended to other shell-and-tube heat exchangers, the analysis presented is this paper concerns the one shell pass and two tube pass configuration, namely 1-2 shell-and-tube heat exchanger. The correction factor is compute by means of an association of e-NTU and LMTD approaches proposed by Kays and London (1998). An analysis of the convergence of the solution provided by the numerical methodology is confronted against results from an analytical solution available in the literature to compute the LMTD correction factor for infinite number of baffles. Numerical results shows that, as the number of baffles is increased, the numerical solution approaches the analytical solution available in the literature. The presented numerical methodology allows the direct computation of the LMTD correction factor for a determined arrangement, giving a new perspective on the project and sizing of shell-and-tube heat exchangers, since typically the analytical solution is applied for all arrangements.

Numerical Procedure for LMTD Correction Factor Calculation for One Tube and One Shell Pass Shell-and-Tube Heat Exchangers

2015 ◽  
Vol 789-790 ◽  
pp. 426-429 ◽  
Author(s):  
Flávio Neves Teixeira ◽  
Luiz Gustavo Monteiro Guimarães ◽  
Matheus dos Santos Guzella ◽  
Luben Cabezas-Gómez ◽  
José Antônio da Silva
Keyword(s):  
Heat Exchanger ◽  
Closed Form ◽  
Correction Factor ◽  
Heat Exchangers ◽  
Numerical Procedure ◽  
Numerical Results ◽  
Dimensionless Parameters ◽  
Analytical Expression ◽  
Tube Heat Exchanger ◽  
Shell And Tube

This paper outlines the application of a numerical procedure to compute the LMTD correction factor for one tube pass and one shell pass, namely 1-1, shell-and-tube heat exchangers. Although the procedure was applied for this specific arrangement, it can easily be applied to different heat exchanger arrangements. The numerical methodology is based on an association of ε-NTU and LMTD approaches introduced by Kays and London (1998). Unlike other shell-and-tube heat exchanger arrangements, such as one tube pass and two shell pass, no available analytical expression in closed form is available in the literature. Hence, the presented numerical procedure is applied to determine the LMTD correction factor for 1-1 shell-and-tube heat exchangers and numerical results were obtained by increasing the number of baffles (1, 3, 7, 9, 19 and 49), in order to analyze the obtained results. Finally, charts for the LMTD correction factor is presented as a function of two dimensionless parameters, namely P and R.

Flanged Joints of Multi-Pass Shell-and-Tube Heat Exchangers Subjected to Non-Axisymmetric Thermal Loading

2010 ◽  
Author(s):  
Natalia Petrova ◽  
Abdel-Hakim Bouzid
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Thermal Loading ◽  
Current Flow ◽  
Finite Element Models ◽  
Bolted Joint ◽  
Tube Heat Exchanger ◽  
Specific Geometry ◽  
Shell And Tube

Despite the fact that multipass shell-and-tube heat exchangers operating at high temperature are subject to frequent problems related to flange sealing, there is neither detailed explanations for the reasons of the failures nor adequate solution to this problem. Specific geometry of multipass heat exchangers and the temperature difference between the inlet and the outlet fluids are responsible for the existence of a thermal circumferential gradient at the shell-to-channel bolted joint. However, existing flange design methods do not address non-axisymmetrical temperature loading of the flanged joint assembly. The circumferential thermal gradient, as the cause of frequent failures to seal the flanged joints, is ignored. This paper outlines the analytical modeling of a flanged joint with a tube sheet of a multipass heat exchanger subjected to a non-axisymmetrical thermal loading. A shell-and-tube heat exchanger of 51 in diameter with co-current flow was used for analysis. The main steps of the theoretical analysis used for the determination of the circumferential temperature profiles and the thermal expansion displacements and distortions of the bolted joint components are given. The results from the proposed analytical model are compared to those obtained from finite element models.

Economic Optimization of Shell and Tube Heat Exchanger Based on Constructal Theory

2010 ◽  
Author(s):  
Majid Amidpour ◽  
Abazar Vahdat Azad
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Constructal Theory ◽  
Economic Optimization ◽  
Total Cost ◽  
Tube Heat Exchanger ◽  
Capital Costs ◽  
Operational Energy ◽  
Shell And Tube

In this paper, the new approach of Constructal theory has been employed to design shell and tube heat exchangers. Constructal theory is a new method for optimal design in engineering applications. The purpose of this paper is optimization of shell and tube heat exchangers by reduction of total cost of the exchanger using the constructal theory. The total cost of the heat exchanger is the sum of operational costs and capital costs. The overall heat transfer coefficient of the shell and tube heat exchanger is increased by the use of constructal theory. Therefore, the capital cost required for making the heat transfer surface is reduced. Moreover, the operational energy costs involving pumping in order to overcome frictional pressure loss are minimized in this method. Genetic algorithm is used to optimize the objective function which is a mathematical model for the cost of the shell and tube heat exchanger and is based on constructal theory. The results of this research represent more than 50% reduction in costs of the heat exchanger.

A Numerical Algorithm and a Graphical Method to Size a Heat Exchanger

2011 ◽  
Author(s):  
Torsten Berning
Keyword(s):  
Heat Exchanger ◽  
Numerical Algorithm ◽  
Heat Exchangers ◽  
Graphical Method ◽  
Application Software ◽  
Microsoft Excel ◽  
Tube Heat Exchanger ◽  
Overall Heat Transfer Coefficient ◽  
Heat Exchanger Design ◽  
Shell And Tube

This paper describes the development of a numerical algorithm and a graphical method that can be employed in order to determine the overall heat transfer coefficient inside heat exchangers. The method is based on an energy balance and utilizes the spreadsheet application software Microsoft Excel™. The application is demonstrated in an example for designing a single pass shell and tube heat exchanger that was developed in the Department of Materials Technology of the Norwegian University of Science and Technology (NTNU) where water vapor is superheated by a secondary oil cycle. This approach can be used to reduce the number of hardware iterations in heat exchanger design.

scholarly journals Thermal Performance in Heat Exchangers by the Irreversibility, Effectiveness, and Efficiency Concepts Using Nanofluids

2020 ◽  
Vol 7 (2) ◽  
pp. F1-F7
Author(s):  
E. Nogueira
Keyword(s):  
Heat Exchanger ◽  
Ethylene Glycol ◽  
Heat Exchangers ◽  
Volume Fraction ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Output Data ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
Effectiveness And Efficiency

The objective of the work is to obtain the outlet temperatures of the fluids in a shell and tube heat exchanger. The second law of thermodynamics is applied through the concepts of efficiency, effectiveness, and irreversibility to analyze the results. Water flows in the shell, and a mixture of water-ethylene glycol is associated with fractions of nanoparticles flows in the tube. Water enters the shell at 27 °C, and the mixture comes to the tube at 90 °C. The mass flow is kept fixed in the shell, equal to 0.23 kg/s, and varies between 0.01 kg/s to 0.50 kg/s. Volume fractions equal to 0.01, 0.10, and 0.25 were considered for analysis, for both nanoparticles from Ag and Al2O3. Results for Reynolds number, heat transfer rate, efficiency, effectiveness, and irreversibility are presented for critique, discussion, and justification of the output data found. It is shown that the flow regime has a significant effect on the performance of the analyzed heat exchanger. Keywords: thermodynamics, second law, ethylene glycol, volume fraction.

scholarly journals DETERMINATION OF CAPITAL COSTS FOR SHELL AND TUBE HEAT EXCHANGER

2020 ◽  
Vol 2020 (1) ◽  
pp. 136-139
Author(s):  
Sergey Scherbin ◽  
Anatoliy Glotov
Keyword(s):  
Heat Exchanger ◽  
Design Parameters ◽  
Tube Heat Exchanger ◽  
Capital Costs ◽  
Shell And Tube ◽  
Heat Carriers

. The capital costs of a shell and tube heat exchanger are considered, taking into account its design parameters and properties of heat carriers

scholarly journals DETERMINATION OF OPERATING COSTS FOR SHELL AND TUBE HEAT EXCHANGER

2020 ◽  
Vol 2020 (1) ◽  
pp. 140-144
Author(s):  
Sergey Scherbin ◽  
Anatoliy Glotov
Keyword(s):  
Heat Exchanger ◽  
Operating Costs ◽  
Design Parameters ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
Heat Carriers

The operating costs of a shell and tube heat exchanger are considered, taking into account its design parameters and properties of heat carriers.

scholarly journals Study on Shell-and-Tube Heat Exchanger Models with Different Degree of Complexity for Process Simulation and Control Design

2018 ◽  
Author(s):  
Javier Bonilla
Keyword(s):  
Heat Exchanger ◽  
Molten Salt ◽  
Heat Exchangers ◽  
Control Strategies ◽  
Thermal Storage ◽  
Working Fluid ◽  
Tube Heat Exchanger ◽  
Test Loop ◽  
Shell And Tube ◽  
Thermal Oil

Many commercial solar thermal power plants rely on indirect thermal storage systems in order to provide a stable and reliable power supply, where the working fluid is commonly thermal oil and the storage fluid is molten salt. The thermal oil - molten salt heat exchanger control strategies, to charge and discharge the thermal storage system, strongly affect the performance of the whole plant. Shell-and-tube heat exchangers are the most common type of heat exchangers used in these facilities. With the aim of developing advanced control strategies accurate and fast dynamic models of shell-and-tube heat exchangers are essential. For this reason, several shell-and-tube heat exchanger models with different degrees of complexity have been studied, analyzed and validated against experimental data from the CIEMAT-PSA molten salt test loop for thermal energy systems facility. Simulation results are compared in steady-state as well as transient predictions in order to determine the required complexity of the model to yield accurate results.

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