Study on the impact of different hole shapes on liquefied gas leakage behavior

Abstract

Accidental leakage of liquefied gas is a common occurrence during its storage, transportation, and usage. The shape of the leakage holes varies due to different causative factors. In this paper, we have established an experimental setup using R134a as the medium to simulate liquefied gas leakage. Different nozzle shapes are used to simulate the effect of various leakage hole shapes on the release process. The results indicate that, when the hole area (A) is constant, the discharge coefficient (Cd(exp)) decreases in the order of circular, square, and triangular holes. Simultaneously, based on dimensional analysis, we propose an empirical formula to predict the Cd(pre) for both circular and non-circular hole leakage. Notably, non-circular holes exhibit an axis-switching phenomenon during flash vaporization spray, leading to an asymmetric structure in the spray cone angle (θ) of triangular holes. The spray area of circular holes displays significantly larger lowest temperature and low-temperature regions compared to non-circular holes.