Coupling Characteristics of a Co-flow Water Mist System and Normal Temperature Counter Air Jets

A co-flow water mist system is considered a clean and efficient emergency handling measure for preventing and controlling the leakage of hazardous gas. To reveal the coupling characteristics of a co-flow water mist system and normal temperature counter air jets, a series of 3D numerical simulations were conducted to visualize the gas-phase flow field as well as the instantaneous trajectories, concentration distribution, and penetration of droplets. The results show that the two-phase flow field can be divided into the co-flow jet or counter jet dominant flow for different initial momentum ratios of the counter jets and the co-flow jet Φ′. Φ′ ≤ 1 is necessary to effectively control the leakage flow. A natural exponential function could be used to fit the dimensionless interaction boundary height z_b* and the characteristic axial momentum ratio Φ for the scenarios of a co-flow water mist system interacting with counter jets. Moreover, a general design method for the co-flow water mist system which could be utilized to prevent and control the leakage of hazardous gas was proposed. The method was tested by a specific case, which shows that it can be used to guide engineering development.