scholarly journals PIV measurement of tube-side in a shell and tube heat exchanger

2018 ◽  
Vol 20 (1) ◽  
pp. 60-66 ◽  
Author(s):  
Kai Wang ◽  
Zixu Zhang ◽  
Qiong Liu ◽  
Xincheng Tu ◽  
Hyoung-Bum Kim
Keyword(s):  
Fluid Flow ◽  
Heat Exchanger ◽  
Tube Bundle ◽  
Flow Distribution ◽  
Minimal Effect ◽  
Vortex Generation ◽  
Tube Heat Exchanger ◽  
Piv Measurement ◽  
Shell And Tube ◽  
Better Than

Abstract In order to improve the performance of the shell and tube heat exchanger, a porous baffle and a splitter bar are employed in this research. Through the arrangement of the porous baffle in the tube-side inlet and the splitter bar in the tube, the flow distribution of liquid in the heat exchanger is improved. PIV technology is used to investigate the unsteady flow in the tube-side inlet and the outlet of different models. The porous baffle significantly improves the flow of fluid in the shell and tube heat exchanger, especially by eliminating/minimizing the maldistribution of fluid flow in the tube-side inlet. The performance of the arc baffle is better than that of the straight baffle. The splitter bar has a minimal effect on the flow field of the tube-side inlet, but it effectively improves the flow in the tube bundle and restrains the vortex generation in the tube-side outlet.

An Investigation Into the Effects of Steam Condensation on Fluid Distribution When Occurring on the Tube Side of a Miniature Shell and Tube Heat Exchanger

2005 ◽  
Author(s):  
Gregory D. MacLeod
Keyword(s):  
Surface Tension ◽  
Heat Exchanger ◽  
Tube Bundle ◽  
Preliminary Investigation ◽  
Flow Distribution ◽  
Fluid Distribution ◽  
Noticeable Effect ◽  
Tube Size ◽  
Tube Heat Exchanger ◽  
Shell And Tube

A hypothesis is evaluated for a miniature shell and tube heat exchanger that the distribution of flow through the tubes is non-uniform when steam condenses inside the tubes. It is believed that due to the small tubing size, surface tension effects, generally negligible in larger exchangers, will have a noticeable effect on distribution of condensate through the tube bundle. This hypothesis was tested using a custom-built miniature shell and tube heat exchanger. The unit consisted of nineteen 0.094” OD tubes (0.010” wall thickness) in a 3/4” OD shell. The effect of both angle of inclination (0°, 45° and 90°) and steam flow regime (loosely defined as low, medium and high) on fluid distribution were investigated. Initial results proved that the flow distribution during condensation on the tube side was non-uniform; within a given trial, each tube produced a significantly different amount of condensate. Furthermore, while at a horizontal angle this non-uniformity was observed to be sporadic with respect to tube location. A tube that produced little condensate in one trial might produce a substantial amount of condensate in a subsequent trial. With increasing angle of inclination, the amount of fluid condensed became more consistent with respect to tube location within the bundle. The experiments were meant to be a preliminary investigation to either prove or disprove the hypothesis. As experimental results did not disprove the hypothesis, future study is recommended. More research into the effects of angle and flow rate on distribution should be conducted. Additionally, the effect of tube size should also be studied. If surface tension is the true explanation for the observed phenomena, it is expected that as the tube size increases, the amount of mal-distribution will be minimized.

scholarly journals Numerical investigation of flow distribution in tubular space of fin-and-tube heat exchanger

2018 ◽  
Vol 240 ◽  
pp. 02011
Author(s):  
Tomasz Stelmach
Keyword(s):  
Heat Exchanger ◽  
Numerical Investigation ◽  
Cfd Simulation ◽  
Tube Bundle ◽  
Cross Flow ◽  
Flow Distribution ◽  
Volumetric Flow Rate ◽  
Tube Heat Exchanger ◽  
Ansys Cfx ◽  
Measurement Results

This paper presents the experimental and numerical investigation of flow distribution in the tubular space of cross-flow fin-and-tube heat exchanger. The tube bundle with two rows arranged in staggered formation is considered. A standard heat exchanged manifold, with inlet nozzle pipe located asymmetrically is considered. The outlet nozzle pipe is located in the middle of the outlet manifold. A developed experimental setup allows one to measure volumetric flow rate in heat exchanger tubes using the ultrasonic flowmeters. The measurement results are then compared with CFD simulation in ANSYS CFX code using the SSG Reynolds Stress turbulence model, and a good agreement is found for tube Re numbers varied from 1800 to 3100.

Flow Distribution on the Tube Side of a High Temperature Heat Exchanger and Chemical Decomposer

2007 ◽  
Author(s):  
Gayatri Kuchi ◽  
Valery Ponyavin ◽  
Yitung Chen ◽  
Steven Sherman ◽  
Anthony E. Hechanova
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Flow Distribution ◽  
Straight Tube ◽  
Baffle Plate ◽  
Pumping Power ◽  
Tube Heat Exchanger ◽  
Temperature Heat ◽  
Shell And Tube ◽  
Flow Maldistribution

Numerical simulations of a high temperature shell and tube heat exchanger and chemical decomposer (thereafter — heat exchanger) with straight tube configuration have been performed using Fluent 6.2.16 code to examine flow distribution on the tube side. The heat exchanger can be a part of sulfur iodine thermochemical water splitting cycle which is one of the most studied cycles for hydrogen production. Uniformity of the flow distribution in the heat exchanger is very critical because the flow maldistribution among the tube or shell sides can result in decreasing of chemical decomposition and increasing of pumping power. In the current study the flow rate uniformity in the heat exchanger tubes has been investigated. Simulations of the straight tube configuration, tube configuration with baffle plate arrangement and with pebble bed region inside the tubes were performed to examine flow distribution on the tube side. It was found the flow maldistribution along the tube direction is very serious with the simple tube configuration. An improvement of the header configuration has been done by introducing a baffle plate in to the header section. With the introduction of the baffle plate, there was a noticeable decrease in the flow maldistribution in the tubes. Uniformity of flow was also investigated with catalytic bed inside the tubes. A significant decrease in flow maldistribution was observed with this arrangement. But if the catalytic bed zone is created on the shell side, then the improved header configuration with a baffle plate is best suitable to avoid flow maldistribution.

Numerical Study of Flow Induced Vibration of the Tube Bundle in a Lash Baffle Shell-and-Tube Heat Exchanger

2013 ◽  
Author(s):  
Haiyang Sun ◽  
Caifu Qian
Keyword(s):  
Heat Exchanger ◽  
Numerical Study ◽  
Tube Bundle ◽  
Lateral Displacement ◽  
Small Hole ◽  
Flow Induced Vibration ◽  
Tube Heat Exchanger ◽  
New Type ◽  
Shell And Tube ◽  
Jet Characteristics

In this paper, flow induced vibration of the tube bundle in a shell-and-tube heat exchanger with a new type of baffle, namely large-and-small-hole or LASH baffle, is studied numerically and compared with that in a segmental baffle shell-and-tube heat exchanger. It is found that as a parallel flow with jet characteristics between the large holes and tubes conducted by the LASH baffles, the fluid-induced vibration of tube bundle in the LASH baffle heat exchanger can be prevented and the lateral displacement variation is greatly decreased.

Comparative CFD Analysis of Maldistribution in a Shell and Tube Heat Exchanger With Conical and Cylindrical Headers

2010 ◽  
Author(s):  
Rohitha Paruchuri ◽  
T. S. Ravigururajan ◽  
Arun Muley
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Transfer Performance ◽  
Static Pressure ◽  
Flow Distribution ◽  
Transfer Performance ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
Improved Performance ◽  
Flow Maldistribution

The analysis of flow maldistribution in a shell and tube heat exchanger is presented. The flow field within the headers was obtained through numerical solution of conservation equations of mass and momentum in addition to the equations of the turbulence model. The flow maldistribution inside the header was a 3-D numerical simulation with the help of commercial software To increase the performance of the heat exchanger, flow maldistribution among the tubes should be minimized.. Flow maldistribution in the header affects the heat transfer performance. The effects of the pressure drop and velocity distribution in the headers were analyzed, as it effects the heat transfer performance. The study showed that by changing the header geometry, the maldistribution can be reduced leading to improved performance. Two types of headers were considered with varying header length and inlet flow velocities from 0.8373mm/sec to 2.344mm/sec are considered. The uniformity of flow distribution improved with increasing header length, whereas it decreased with increasing flow rate. As the header length increased to 1500mm the flow maldistribution decreased and the static pressure was almost equal for all the tubes in case of a conical header. The results show that conical header minimizes flow maldistribution compared to a cylindrical header.

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