98/03254 Heat transfer augmentation of shell-and-tube heat exchangers for the chemical processing industry

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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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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Performance Analysis and Design Optimization of Shell and Tube Heat Exchangers

10.21203/rs.3.rs-407371/v1 ◽

2021 ◽

Author(s):

praveen math

Keyword(s):

Heat Transfer ◽

Heat Exchanger ◽

Heat Exchangers ◽

Pressure Loss ◽

Fluid Flows ◽

Hot Water ◽

Flow Conditions ◽

Shell Side ◽

Shell And Tube ◽

Side Flow

Abstract Shell and Tube heat exchangers are having special importance in boilers, oil coolers, condensers, pre-heaters. They are also widely used in process applications as well as the refrigeration and air conditioning industry. The robustness and medium weighted shape of Shell and Tube heat exchangers make them well suited for high pressure operations. The aim of this study is to experiment, validate and to provide design suggestion to optimize the shell and tube heat exchanger (STHE). The heat exchanger is made of acrylic material with 2 baffles and 7 tubes made of stainless steel. Hot fluid flows inside the tube and cold fluid flows over the tube in the shell. 4 K-type thermocouples were used to read the hot and cold fluids inlet and outlet temperatures. Experiments were carried out for various combinations of hot and cold water flow rates with different hot water inlet temperatures. The flow conditions are limited to the lab size model of the experimental setup. A commercial CFD code was used to study the thermal and hydraulic flow field inside the shell and tubes. CFD methodology is developed to appropriately represent the flow physics and the procedure is validated with the experimental results. Turbulent flow in tube side is observed for all flow conditions, while the shell side has laminar flow except for extreme hot water temperatures. Hence transition k-kl-omega model was used to predict the flow better for transition cases. Realizable k- epsilon model with non-equilibrium wall function was used for turbulent cases. Temperature and velocity profiles are examined in detail and observed that the flow remains almost uniform to the tubes thus limiting heat transfer. Approximately 2/3 rd of the shell side flow does not surround the tubes due to biased flow contributing to reduced overall heat transfer and increased pressure loss. On the basis of these findings an attempt has been made to enhance the heat transfer by inducing turbulence in the shel l side flow. The two baffles were rotated in opposite direction to each other to achieve more circulation in the shell side flow and provide more contact with tube surface. Various positions of the baffles were simulated and studied using CFD analysis and th e results are summarized with respect to heat transfer and pressure loss.

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