Design and analysis of the thermal insulation system for a new independent type B LNG carrier

The geometrical arrangement and thermal insulation performance of the thermal insulation system are two of the most crucial issues for the design of the cargo containment system (CCS) for LNG carriers. In this paper, the features of a new independent type B CCS were firstly highlighted in comparison with the CCSs of conventional membrane-type and MOSS independent spherical type of the liquefied natural gas (LNG) carriers. In the following, a new thermal insulation system for the new independent type B CCS was designed and discussed. The conductivities of the insulation materials were tested and the heat transfer model for one typical tank of this carrier was established and simulated by using ANSYS Fluent software based on the analyses of the hull and CCS structures. The boil off rate (BOR) and temperature field for the new CCS were obtained based on the numerical simulation, in order to quantitatively evaluate the thermal insulation performance. It was found that the new independent type B CCS could efficiently prevent the environment heat inflow for the LNG vaporization and ensure the safety for the inner hull structures of the LNG carrier.