(89e) Study on the Heat Transfer of Expansion Foam on LNG Pool

Expansion foam is one of the important safety measures to control vapor dispersion and fire suppression. It has been recognized that the effectiveness of expansion foam may be achieved by reducing the LNG vapor density to make it positively buoyant by increasing its temperature adding heat from water in the foam to LNG vapors while penetrating through the foam.

The effectiveness of expansion foam for vapor dispersion control is very dependent on the thickness of foam to cover LNG pool. If the foam thickness is relatively small, it may not provide enough heat to LNG vapors up to reach positive buoyancy. In the LNG facilities, the possible incident scenarios might involve bigger releases due to its huge storage and processing capacity. Intuitively, in case of larger amounts of LNG release, it might require bigger foam depth because the larger LNG, the bigger needs of heat input from water in the foam by larger foam depth for the similar effect of vapor control. Therefore, it is very important to identify minimum effective foam thickness for vapor dispersion control. Consequently, heat transfer study on the LNG and expansion foam associated with field experiments is very necessary to obtain the required expansion foam depth for the safety of LNG or other flammable fuels.

Therefore, in this paper, heat transfer study between LNG and expansion foam is conducted and its results are compared with experimental results achieved by Mary Kay O'Connor Process Safety Center (MKOPSC) to validate the model. Finally, this generalized heat transfer study will allow us to estimate the effective foam depth for all kinds of LNG pool scenarios. Moreover, this paper will provide the basis for the estimation of minimum effective foam depth in case of foam application on fire, which is more complicated than the vapor control case.