(162d) Experimental Study of Effective Water Spray Curtain Application in Dispersing Lng Vapor Clouds

The need for installing new LNG storage facilities in the US to meet the demand of natural gas has increased the attention on LNG safety issues. Because of highly flammable nature, LNG poses several hazards to the workers and the surrounding communities. One of the major hazards is the formation of flammable vapor cloud from any accidental LNG release, which may result in a massive fire. The safety measures to prevent and mitigate accidental LNG release are essential and critical to protect people.

Water spray curtain is a promising technique to control and mitigate many toxic and flammable vapors. Much theoretical and experimental work has been carried out to determine the effectiveness of water spray curtains in dispersing heavier vapor. LNG vapor dispersion behaves differently from other dense gases due to its low molecular weight and extremely low temperature. In that context, it is essential to carry out research to understand the effects of water curtain on LNG vapor clouds. There have been a limited number of publications on the use of water spray curtain to mitigate LNG vapor clouds. These previous research show that water spray curtains can enhance LNG vapor dispersion from small spills. However many key questions still remain to be answered to develop comprehensive and structured engineering guidelines for the design of an effective water spray curtain for controlling LNG vapor.

An experimental methodology to study the LNG vapor dispersion behavior with the application of water spray curtain has been presented. This field experiment involves the fundamental study of forced dispersion, dilution due to air entrainment, and heat exchange to determine the effectiveness of water spray in reducing the LNG vapor ?exclusion zone?. The paper discusses and exemplifies the method with the results to emphasize the observed effectiveness of water spray curtain.