Release behaviour of a high-pressure vapor vessel with condensation: Test and modeling study

Abstract

• The vapor release test with condensation is conducted with three micro-cracks. • The ideal dropwise condensation and wall heat conduction are considered. • A six-equation vapor leakage model is presented with a bubbly flow assumption. • A blowdown model coupling with a leakage model is employed to simulate vapor release. A phenomenon of accidental release from a high-pressure containment into a low-pressure environment is significant in several industrial systems such as chemical reactors and pipeline transportation and storage. The paper aims to investigate the vapor release with condensation, and to develop a vapor release model coupling a blowdown model with a critical flow model. Vapor release tests of the pressurized vessel are performed with micro-cracks, and the fluid pressure and temperature evolutions are recorded. The theory of ideal dropwise condensation is used to describe the interfacial heat transfer, and the wall heat transfer is regarded as the heat conduction in a blowdown model. A six-equation model allowing the vapor leakage simulation with condensation is presented with a bubbly flow regime assumption. The vapor release model is composed of a critical flow model in conjunction with a vessel blowdown model, including the treatment of the vapor condensation, interfacial heat transfer, and interfacial force during the depressurization. The proposed model predictions exhibit strong similarities with the measured evolutions of the fluid pressure, temperature, and the total weight of the released fluid. Finally, the qualitative analysis of the vapor release with a heat transfer/adiabatic process is conducted. The vapor condensation occurs during the release process when the initial pressure is increased, while the condensation is reduced for a heat transfer process. The release time and vapor condensation of the pressurized vessel are significantly affected by the vessel volume and break area.