Modelling of Level Swell in a Pressurized Vessel During Venting
Loading...
Date
2021-07-14
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Runaway reactions are a serious hazard in the process industry due to the magnitude of the potential consequences they can have, as evidenced by the disasters in Seveso (1976), Bhopal (1984), and Vishakapatnam (2020). Emergency relief systems act as a mitigative layer of protection by removing the vessel's contents and relieving its pressure. Thus, it is imperative for the safe operation of chemical processes to adequately size the ERS.
Current ERS sizing methods have limitations that lead to the oversizing of vents for some systems. This problem has necessitated the development of dynamic models that can accurately describe the behavior of a vessel undergoing a runaway reaction during the entire venting process.
The dynamic simulator under development at TAMUQ is a step forward in this direction. The simulator includes robust thermodynamic equations coupled with kinetic and fluid dynamic models that simulate the vessel’s behavior from the onset of reaction runaway until the end of venting into a catch tank. This work completes the simulator by incorporating a level swell model to account for the rise in liquid level within the vessel as bubbles accumulate in the liquid phase due to boiling or gas generation. This allows for the automatic determination of the onset and termination of two-phase venting during vessel depressurization. This additional information is imperative to the accurate sizing of ERS because two-phase venting requires larger ERS.
Accordingly, this work includes the implementation of a level swell model into the simulator, and a qualitative sensitivity analysis on the modified simulator to study the effects of varying venting conditions on level swell.
Description
Keywords
Level swell, Dynamic Simulator, Emergency Relief