Original Paper(Vol.63 No.2 pp.125-130)

Numerical Simulation of Gas Diffusion Considering Mitigation with Water Curtain for Risk Assessment

Kento IKEDA and Tetsusei KURASHIKI

Abstract:Recently, Risk-Based Maintenance (RBM) methodology has been used for managing the overall risk of fixed equipment in the petrochemical and chemical process plants. The risk is obtained by multiplying the probability of failure and the consequence of failure. In this paper, the simulation technique of gas diffusion was proposed due to evaluate the consequence with considering the effect of water curtain. Firstly, we calculated the coefficient of wash-out by water curtain, and estimated the gas diffusion with considering the virtual sources due to the wet deposition. The relation between the diffused area and the number of nozzles of water curtains can be estimated by the proposed method. Furthermore, the estimation method of gas diffusion considering the effects of aspirate and dry deposition was proposed. From the numerical results, the proposed technique is useful for an evaluation of consequence of failure in petrochemical plants considering mitigation.

Key Words:RBM, Consequence, Simulation, Gas diffusion, Mitigation, Water curtain