CFD Investigation of Solid CO_(2) Formation and Dispersion in High-Pressure Pipeline Leakage EventsOA

This study investigates the leakage and dispersion behavior of high-pressure CO_(2) in long-distance pipelines using computational fluid dynamics(CFD)coupled with a regional-scale modeling framework.The influence of key operational and environmental parameters,including transport temperature,pressure,pipeline diameter,leak orifice size,and ambient wind speed,is systematically examined,with particular emphasis on their role in governing the spatial extent of solid CO_(2) formation.The results indicate that the evolution of the leakage flow field is governed by a strong coupling between thermodynamic effects and fluid dynamic processes.Elevated temperatures delay the formation of the Mach disk structure,while higher pressures enhance jet momentum,suppress turbulent mixing,and consequently slow the decay of CO_(2) concentration.Smaller pipeline and leak diameters promote the development of deep,localized low-temperature cores due to reduced thermal inertia.In contrast,increased wind speeds significantly enhance convective heat and momentum exchange,accelerating both dispersion and warming of the CO_(2) plume.Overall,the temperature and pressure state of the transported CO_(2) emerges as the primary internal control on dry ice formation,whereas geometric constraints and atmospheric conditions govern the accumulation and transport of cold energy.The findings highlight critical risk conditions associated with low transport temperatures,high operating pressures,small leak diameters,and low-wind environments,which collectively favor the formation of extended solid CO_(2) deposition zones.