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

Abstract

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.