Analysis of two main LNG CCS (cargo containment system) insulation boxes for leakage safety using experimentally defined thermal properties

Given that LNG cargo containment systems (CCS) operate in a range of environmental temperatures that includes cryogenic temperatures, thermal analysis should be carried out to determine their insulation capabilities. CCS components consist of various materials, and the temperature distribution of the CCS insulation box is the main concern. For this study an experiment was conducted to measure the thermal conductivity of insulation materials used in a LNG CCS under various temperature conditions ranging from room temperature to cryogenic temperature. Using the experimentally determined thermal properties a steady-state thermal analysis of a CCS insulation box was investigated. In addition a thermal analysis was conducted for the hull part of a carrier ship in a scenario in which LNG leaked through the secondary barrier of the insulation due to an accident. The safety of the hull was considered based on the ductile-to-brittle transition temperature of the hull.

► Experiment of thermal conductivity of LNG CCS insulation materials is conducted.
► Each insulation CCS box has superior insulation function from the steady state result.
► In transient result, thermal safety is guaranteed for hull with the bottom plywood.
► Without the bottom plywood, the thermal safety depends on lots of factors.
► The factors are the saturated leaked area and leaked mass flow rate of the LNG.