Myungbae Kim
Korea Institute of Machinery & Materials, South Korea
Title: Evaporation velocity of cryogenic liquid with and without spreading
Biography
Biography: Myungbae Kim
Abstract
The study of liquid pool spreading plays an essential role in the quantitative risk assessment of accidentally released cryogenic liquids, such as LNG and liquefied hydrogen because the spreading of such liquids is the first step in the development of multi-staged accident sequences leading to a major disaster. There is a wide range of models used to describe the spreading of a cryogenic liquid pool. Many of these models require evaporation velocity, which has to be determined experimentally because the heat transfer process between the liquid pool and the surroundings is too complicated to be modeled. Measurement of the evaporation velocity had been conducted in the first place with a non-spreading pool that was formed by pouring of cryogenic liquid onto bounded ground instantaneously so that the discharge time was much smaller than the total evaporation time. Recently, the measurement methodology for a spreading pool was developed by the research team including the author. A constantly-released-flow onto unbounded ground was intended to generate the spreading pool because in almost all real accidents, a cryogenic liquid spills and spreads over a large or unbounded ground such that the pool spreading process should be taken into account. In case of the spreading pool, a greater release flow rate is found to result in a greater evaporation velocity, and the evaporation velocity decreases with the spreading time. Since the spreading pool in the author’s work receives heat more effectively from the ground as compared to the non-spreading pool, the measured evaporation velocities are much greater in the spreading pool than in the non-spreading pool.