Pressure Variation in Low Pressure Side of Shell and Tube Heat Exchanger After Tube Rupture

Author(s):  
Ganesh S. Katke ◽  
M. Venkatesh ◽  
N. P. Gulhane

This paper presents an analytical algorithm to determine the pressure variation on the Low Pressure side of a Shell and Tube Heat Exchanger (STHE) after a tube rupture and its validation using CFD simulation. STHEs are often used for exchanging heat between high-pressure (HP) and low-pressure (LP) fluids in the chemical process industry. In case tube rupture occurs in a STHE having a large pressure difference between HP and LP side, there is a risk of release of significant quantity of fluid from the HP side to the LP side. The consequent pressure build-up can lead to the failure of LP side pressure envelope. Generally, design pressure of the LP side is about 10–20% higher than the operating pressure of the LP side fluid, but well below the operating pressure on the HP side. There is no well-established methodology to design the LP side to withstand sudden release of high pressure fluid following a tube rupture. Three dimensional analyses were carried out using Computational Fluid Dynamics to study the pressure variation in LP side (shell side) of a Gas Cooler and to validate the results obtained from the analytical algorithm. It has been observed that the pressure on the LP side exceeds the design pressure instantaneously due to generation of a pressure pulse after tube rupture. This may lead to damage of LP envelope (shell) and internal structure of STHE.

Author(s):  
David R. Thornton ◽  
Robert A. Sadowski ◽  
Philip A. Henry

As part of operations, petrochemical and process plants sometimes require the exchange of heat between a high pressure fluid and a lower pressure fluid in shell-and-tube heat exchangers. In most cases, the high pressure fluid exists on the tubeside and the lower pressure is on the shellside. While rare, it is possible for a tube inside the exchanger shell to rupture suddenly, releasing the high pressure fluid into the shellside. If the pressure of the high pressure fluid exceeds the design pressure of the low pressure shell or its attached piping, it might be possible for the resulting pressure in the low pressure side to exceed permitted values. In such cases, API 521 provides guidance on assuring that sufficient pressure relief is available to limit the pressures on the heat exchanger(s)’ low pressure side. An overpressure analysis per API 521 can include both steady-state and transient analysis methods for determining that the pressures remain within acceptable levels. In situations where a large pressure differential exists between the high and low pressure sides of the exchanger, the transient, hydraulic analysis of the tube rupture event can be used as a tool to help mitigate over pressure. After briefly discussing the analysis methodology, this paper discusses some of the practical considerations and decisions that normally go into conducting the analysis.


1979 ◽  
Author(s):  
W. Hilary Lee

The effect of high pressure inside and outside of tubes and of pressure ratios on tube spacings associated with minimum volume and minimum weight of shell-and-tube gas turbine recuperators, is examined. For this purpose, a method was developed for analyzing volume and weight of shell-and-tube heat exchanger surfaces. The influence of TEMA recommended minimum spacing-to-diameter ratio on the result is discussed. Implications of the above findings on gas turbine recuperator design is sketched.


2010 ◽  
Vol 53 (21-22) ◽  
pp. 4543-4551 ◽  
Author(s):  
Yan Li ◽  
Xiumin Jiang ◽  
Xiangyong Huang ◽  
Jigang Jia ◽  
Jianhui Tong

Author(s):  
Partha Pratim Saikia ◽  
Abhik Majumder

Shell and tube heat exchanger (STHX) is a class of indirect contact heat exchangers which has wide applications in various industries. In this paper, the shell-side performance characteristics of a small STHX with differently notched continuous helical baffle (CHB) geometries are numerically studied and compared with same CHB without notched regions. The indentations are uniquely produced by placing the notch near the core of the heat exchanger, thereby conferring the flow with low-pressure drop regions. Two set of models of inner notched continuous helical baffle (ICHB), i.e., ICHB1 and ICHB2, are studied with notch width of about 5% and 10% of the inner shell diameter of the same heat exchanger. In comparison with the CHBSTHX, it is seen that the STHXs incorporated with ICHBs, the heat transfer rate dropped slightly, but a significant decrease in pressure drop is observed. It is found that the heat transfer coefficient to pressure drop ratio for ICBH1 and ICHB2 shows significant increase in comprehensive performance of about 3.5% and 32.42%, respectively, when compared with same CHB without notched regions.


Author(s):  
Leonardo Cavalheiro Martinez ◽  
Leonardo Cavalheiro Martinez ◽  
Viviana Mariani ◽  
Marcos Batistella Lopes

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Swanand Gaikwad ◽  
Ashish Parmar

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.


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