Shell-side velocities in shell-and-tube exchangers

2017 ◽  
Author(s):  
J. M. Chenoweth
Keyword(s):  
Shell Side ◽  
Shell And Tube

Numerical simulation of the effect of baffle cut and baffle spacing on shell side heat exchanger performance using CFD

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Swanand Gaikwad ◽  
Ashish Parmar
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Numerical Results ◽  
Shell Side ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
Two Parameters

AbstractHeat exchangers possess a significant role in energy transmission and energy generation in most industries. In this work, a three-dimensional simulation has been carried out of a shell and tube heat exchanger (STHX) consisting of segmental baffles. The investigation involves using the commercial code of ANSYS CFX, which incorporates the modeling, meshing, and usage of the Finite Element Method to yield numerical results. Much work is available in the literature regarding the effect of baffle cut and baffle spacing as two different entities, but some uncertainty pertains when we discuss the combination of these two parameters. This study aims to find an appropriate mix of baffle cut and baffle spacing for the efficient functioning of a shell and tube heat exchanger. Two parameters are tested: the baffle cuts at 30, 35, 40% of the shell-inside diameter, and the baffle spacing’s to fit 6,8,10 baffles within the heat exchanger. The numerical results showed the role of the studied parameters on the shell side heat transfer coefficient and the pressure drop in the shell and tube heat exchanger. The investigation shows an increase in the shell side heat transfer coefficient of 13.13% when going from 6 to 8 baffle configuration and a 23.10% acclivity for the change of six baffles to 10, for a specific baffle cut. Evidence also shows a rise in the pressure drop with an increase in the baffle spacing from the ranges of 44–46.79%, which can be controlled by managing the baffle cut provided.

scholarly journals Shell-Side Pressure Drop in the Multi-Baffled Shell-and-Tube Heat Exchangers

1965 ◽  
Vol 8 (32) ◽  
pp. 644-651 ◽  
Author(s):  
Seikan ISHIGAI ◽  
Eiichi NISHIKAWA ◽  
Yoshiaki NAKAYAMA ◽  
Shigeo TANAKA ◽  
Ikuo SAIDA ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Heat Exchangers ◽  
Shell Side ◽  
Side Pressure ◽  
Shell And Tube

scholarly journals Performance Analysis and Design Optimization of Shell and Tube Heat Exchangers

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.

3-D Numerical Simulation of the Vapor-Liquid Flow at the Shell Side of Shell-and-Tube Heat Exchangers

2016 ◽  
Author(s):  
Qi Xiao ◽  
Ning Yang ◽  
Zhenxing Zhao ◽  
Chunhui Dai ◽  
Jun Wu ◽  
...  
Keyword(s):  
Liquid Flow ◽  
Heat Exchangers ◽  
Volume Fraction ◽  
Heated Wall ◽  
Bulk Temperature ◽  
Subcooled Boiling ◽  
Shell Side ◽  
Boiling Process ◽  
Shell And Tube ◽  
Vapor Liquid

The boiling vapor-liquid flow at the shell side of shell-and-tube heat exchangers was simulated by Euler-Euler transient 3D method in this paper. The mass and heat transfers between the two-phase fluid and heated wall for the subcooled boiling phenomenon were described by the Rensselaer Polytechnic Institute model (RPI model), while the steam condensation within the subcooled liquid was described by the Lee model. Firstly, different turbulence and interfacial force models were evaluated by comparing with the experimental data of Bartolomej (1982). It was found that the turbulence models have minor influence on the temperature and vapor volume fraction distributions. As the bubble size in the subcooled boiling process is small (usually <1 mm), the velocity slip between the vapor bubbles and the liquid is not so important. The simulation results using different drag force models are similar, and the Tomiyama model offers relatively better predictions. The non-drag forces could not significantly improve the accuracy in our simulations. Then the gas-liquid boiling flow at the shell side of shell-and-tube heat exchangers was then simulated. It was found that the water temperature increases almost linearly near the inlet zone, and the increase speed was slowed down when the bulk temperature approached to the saturated point as the boiling process happened more frequently and consumed much heat. The heat exchangers with the triangle and square configurations have similar temperature and vapor distributions. Further analyses for those two kinds of tube configurations are needed.

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