Experimental study on optimization models for evaluation of fireball characteristics and thermal hazards induced by LNG vapor Cloud explosions based on colorimetric thermometry

In order to facilitate transport, natural gas is cooled down by a cycle process of compression, condensation, expansion, and evaporation that transforms the gas into a liquid form, as known as Liquefied Natural Gas (LNG). However, once any leak happens in the transportation pipeline, it will result in serious thermal radiant damage due to the explosion fireball induced by LNG Vapor cloud explosions. In this work, an optimization fireball model is proposed by introducing the atmospheric transmission rater into the original TNO dynamic model. Based on the colorimetric thermometry technology, a full-scale LNG pipeline explosion experiment has been conducted and a series of testing data for the thermal radiant by VCEs' fireball have been obtained. It is found that theoretical predictions by using optimization model agree well with experimental data. According to the thermal radiant damage criterion, it is concluded that a near 100% fatality radius is expected within the range of 266.3 m and there is a safety area with an ellipse diameter of 1180.1 m. This work attempts to develop optimization fireball models to predict the thermal radiant damage more accurately, and improve the performance of risk assessment on LNG transport and storage industrial process.