Experimental and estimated determination of heat transfer parameters in the channels of additive shell-and-tube heat exchangers

Shell and tube heat exchangers in their various construction modifications are probably the most widespread and commonly used basic heat exchanger configuration in the process industries. There are many modifications of the basic configuration which can be used to solve special problems. Baffles serve two functions: Most importantly, they support the tubes in the proper position during assembly and operation and prevent vibration of the tubes caused by flow-induced eddies, and secondly, they guide the shell-side flow back and forth across the tube field, increasing the velocity and the heat transfer coefficient. The objective of this paper is to find the baffle spacing at fixed baffle cut that will give us the optimal values for the overall heat transfer coefficient. To do this Microsoft Excel 2003 package was employed. The results obtained from previous studies showed that to obtain optimal values for the overall heat transfer coefficient for the shell and tube heat exchangers a baffle cut of 20 to 25 percent of the diameter is common and the maximum spacing depends on how much support the tubes need. This was used to validate the results obtained from this study.

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Thermal Effectiveness of Multiple Shell and Tube Pass TEMA E Heat Exchangers

Journal of Heat Transfer ◽

10.1115/1.3250472 ◽

1988 ◽

Vol 110 (1) ◽

pp. 54-59 ◽

Cited By ~ 2

Author(s):

A. Pignotti ◽

P. I. Tamborenea

Keyword(s):

Heat Transfer ◽

Heat Capacity ◽

Heat Transfer Coefficient ◽

Heat Exchangers ◽

Rate Ratio ◽

Algebraic Solution ◽

Tube Heat Exchanger ◽

Transverse Mixing ◽

Shell And Tube ◽

The Heat Transfer Coefficient

The thermal effectiveness of a TEMA E shell-and-tube heat exchanger, with one shell pass and an arbitrary number of tube passes, is determined under the usual symplifying assumptions of perfect transverse mixing of the shell fluid, no phase change, and temperature independence of the heat capacity rates and the heat transfer coefficient. A purely algebraic solution is obtained for the effectiveness as a function of the heat capacity rate ratio and the number of heat transfer units. The case with M shell passes and N tube passes is easily expressed in terms of the single-shell-pass case.

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A Critical Review on the Determination of Pressure Drop During Condensation in Smooth and Enhanced Tubes

Volume 2: Heat Transfer Enhancement for Practical Applications; Heat and Mass Transfer in Fire and Combustion; Heat Transfer in Multiphase Systems; Heat and Mass Transfer in Biotechnology ◽

10.1115/ht2013-17567 ◽

2013 ◽

Author(s):

Ahmet Selim Dalkiliç ◽

Ali Celen ◽

Mohamed M. Awad ◽

Somchai Wongwises

Keyword(s):

Neural Network ◽

Heat Transfer ◽

Experimental Data ◽

Heat Transfer Coefficient ◽

Transfer Coefficient ◽

Critical Review ◽

Heat Exchangers ◽

Numerical Analyses ◽

Enhanced Tubes

Heat exchangers using in-tube condensation have great significance in the refrigeration, automotive and process industries. Effective heat exchangers have been rapidly developed due to the demand for more compact systems, higher energy efficiency, lower material costs and other economic incentives. Enhanced surfaces, displaced enhancement devices, swirl-flow devices and surface tension devices improve the heat transfer coefficients in these heat exchangers. This study is a critical review on the determination of the condensation heat transfer coefficient of pure refrigerants flowing in vertical and horizontal tubes. The authors’ previous publications on this issue, including the experimental, theoretical and numerical analyses are summarized here. The lengths of the vertical and horizontal test sections varied between 0.5 m and 4 m countercurrent flow double-tube heat exchangers with refrigerant flowing in the inner tube and cooling water flowing in the annulus. The measured data are compared to theoretical and numerical predictions based on the solution of the artificial intelligence methods and CFD analyses for the condensation process in the smooth and enhanced tubes. The theoretical solutions are related to the design of double tube heat exchangers in refrigeration, air conditioning and heat pump applications. Detailed information on the in-tube condensation studies of heat transfer coefficient in the literature is given. A genetic algorithm (GA), various artificial neural network models (ANN) such as multilayer perceptron (MLP), radial basis networks (RBFN), generalized regression neural network (GRNN), and adaptive neuro-fuzzy inference system (ANFIS), and various optimization techniques such as unconstrained nonlinear minimization algorithm-Nelder-Mead method (NM), non-linear least squares error method (NLS), and Ansys CFD program are used in the numerical solutions. It is shown that the convective heat transfer coefficient of laminar and turbulent condensing film flows can be predicted by means of theoretical and numerical analyses reasonably well if there is a sufficient amount of reliable experimental data. Regression analysis gave convincing correlations, and the most suitable coefficients of the proposed correlations are depicted as compatible with the large number of experimental data by means of the computational numerical methods.

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Optimization of heat transfer in shell-and-tube heat exchangers using MOGA algorithm: adding nanofluid and changing the tube arrangement

Chemical Engineering Communications ◽

10.1080/00986445.2021.1983548 ◽

2021 ◽

pp. 1-15

Author(s):

Yacine Khetib ◽

Hala M. Abo-Dief ◽

Abdullah K. Alanazi ◽

S. Mohammad Sajadi ◽

Suvanjan Bhattacharyya ◽

...

Keyword(s):

Heat Transfer ◽

Heat Exchangers ◽

Tube Arrangement ◽

Shell And Tube

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Biofouling Monitors for Noncylindrical OTEC Heat Exchanger Tubes

Journal of Solar Energy Engineering ◽

10.1115/1.3266310 ◽

1982 ◽

Vol 104 (3) ◽

pp. 257-261

Author(s):

T. M. Kuzay ◽

C. B. Panchal ◽

A. P. Gavin

Keyword(s):

Heat Transfer ◽

Heat Exchangers ◽

Steel Tube ◽

Stainless Steel Tube ◽

Thermal Energy Conversion ◽

Shell And Tube ◽

Ocean Thermal Energy ◽

Analytical Approaches

Heat-transfer monitors (HTMs) have been used since 1976 to measure the reduction in the seawater heat-transfer coefficient due to buildup of biofouling and corrosion products inside circular tubes of shell-and-tube heat exchangers being developed for ocean thermal energy conversion (OTEC) plants. For OTEC heat exchangers (HXs) with other tube geometries, special, modified HTMs, which we call STMs, are being sought. The analytical approaches and calibration results to date are summarized for STMs of two types: (i) an STM simulating a rectangular seawater passage in a compact, aluminum, plate-fin HX, and (ii) an STM for a helical stainless-steel tube. The development of type 1 has been successful. A software change is needed for type 2.

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