Estimation of the Size of Stagnation Zones on the Territory of the Propane-Butane Tank Farm Aimed at Increasing the Safety of the Facility

Abstract

The safety of the territory is directly dependent upon the propane-butane storage and use technology. The paper reveals the efficiency of FlowVision software-based computational fluid dynamics technology (CFD) in modeling the stagnation zones and the behavior of fuel-air mixture (FAM) cloud within the territory of storage facilities. Propane-butane storage tank farm storage was selected as the object of research. CAD SolidWorks was used in the design of his three-dimensional model. Methods using "dispersed heavy gas models" have been developed. It is based on the numerical solution of three-dimensional fluid and gas dynamics equations, including the laws of conservation of mass, momentum (the Navier-Stokes equation) and constitutive equation. Recommendations on changes to be implemented during the design stage of tank farms with propane-butane mixture have been developed in order to increase facility safety in case of equipment depressurization. It is known that buildings, located on the territory, impair the airflow, resulting in the presence of large stagnant zones. It has been established that as a result of the movement of air flow through the territory of the tank farm, the maximum areas of stagnation zones are observed with the north wind and the minimum – with the southeast wind. Using the three-dimensional modeling techniques and finite volumes the stagnation zones in the tank farm were computed for different wind directions and measurement heights, enabling a comprehensive assessment of the situation at the facility in question and development of series of safety-increasing measures.