Flow Induced Vibration in a Heat Exchanger With Seal Strips

1982 ◽  
Vol 104 (2) ◽  
pp. 372-378
Author(s):  
J. H. Kissel
Keyword(s):  
Heat Exchanger ◽  
Velocity Profile ◽  
Natural Frequency ◽  
Water Flow ◽  
Critical Section ◽  
Shell Side ◽  
Flow Induced Vibration ◽  
Shell And Tube ◽  
Vibration Tests ◽  
Head Type

Flow induced vibration tests using water as the shell side medium were conducted on a shell and tube exchanger with single segmental baffles and various tube layouts. The heat exchanger was of the externally packed floating head type with seal strips that directed the water flow into the bundle to prevent by-passing of the fluid between the bundle and the shell. High localized velocities exist in the vicinity of the seal strips and contributed directly to the vibration problem. The tube natural frequency for various baffle spacings was measured at the vibration point and a gap velocity at the critical section of the bundle was estimated. A correlation was then made with these parameters and the fluidelastic excitation theory. A discussion of the velocity profile through the heat exchanger is included.

scholarly journals Cause analysis of vibration in shell-and-tube heat exchanger

2021 ◽  
Vol 353 ◽  
pp. 01002
Author(s):  
Jia Wu ◽  
Jiansheng Hu ◽  
Bin Du ◽  
Ping Tang ◽  
Jie Tang
Keyword(s):  
Heat Exchanger ◽  
Flow Rate ◽  
Tube Bundle ◽  
Oil Refining ◽  
Process Equipment ◽  
Shell Side ◽  
Flow Induced Vibration ◽  
Tube Heat Exchanger ◽  
Acceleration Sensors ◽  
Shell And Tube

Heat exchanger is a universal process equipment, which is widely used in chemical industry, oil refining, thermal power and other industries. Shell-and-tube heat exchangers often fail prematurely due to flow-induced vibration. In this paper, aiming at the problem of severe vibration of shell-and-tube heat exchanger in an enterprise, the vibration acceleration sensors are used to measure the vibration of shell and tube side of heat exchanger. Through the analysis of the measurement results, it is found that when the flow rate on the shell side of the heat exchanger is greater than 50000 Nm3/h, the flow-induced vibration of the tube bundle occurs, and the vibration frequency is 57Hz, which is close to the natural frequency of the tube bundle. And the greater the flow rate on the shell side, the more intense the vibration. In order to reduce the vibration of heat exchanger, the damping measure of inserting baffles between tubes is adopted.

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 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.

CFD Modeling and Analysis of a Shell-and-Tube Heat Exchanger

2008 ◽  
Author(s):  
Ender Ozden ◽  
I˙lker Tarı
Keyword(s):  
Heat Exchanger ◽  
Turbulence Modeling ◽  
Turbulence Models ◽  
Temperature Fields ◽  
Cfd Modeling ◽  
Shell Side ◽  
Cfd Simulations ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
Side Flow

A shell-and-tube heat exchanger is modeled and numerically analyzed using a commercial finite volume CFD package. The heat exchanger is small, has a single shell and a single tube pass, and its shell side is baffled. The baffles are 25% or 36% cut single-segmental baffles. Tube layout is the staggered layout with a triangular pitch. There is no leakage from baffle orifices and no gap between the baffles and the shell. It is observed that the shell side flow and the temperature distributions are very sensitive to modeling choices such as mesh, order of discretization and turbulence modeling. Various turbulence models are tried for the first and second order discretizations using two different mesh densities. CFD predictions of shell side pressure drop and overall heat transfer coefficient are obtained and compared with Kern and Bell-Delaware method results. After selecting the best modeling approach, the sensitivity of the results to flow rates and the baffle spacing is investigated. It is observed that the flow and temperature fields obtained from CFD simulations can provide valuable information about the parts of the heat exchanger design that need improvement. Correlation based approaches may indicate the existence of the weakness but CFD simulations can also pin point the source and the location of it. Using CFD together with experiments may speed up the design process and may improve the final design.

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