Experimental evaluation and quantitative modeling of thermal behavior of surface-attached insulation polymers and steel structures under combustion

The surfaces of liquefied petroleum gas (LPG) storage vessels are usually coated with polymer insulation to maintain low temperatures. However, this insulation layer poses a potential fire risk. This study aimed to investigate the heat feedback mechanism and its impact on steel structures when bonded thermal insulation materials combust. Thermal insulation materials were bonded to Q345 steel surface, which is commonly used in LPG storage tanks, and experiments were conducted by designing a burning experimental rig of the combustible material attached to steel plate. Results revealed the existence of an equivalent temperature layer in the flame zone above the insulation material. Equations for predicting radiative and convective heat feedback were formulated. As combustion of the insulation material stabilized, the predicted heat feedback from the equations closely matched experimental values. A quantitative evaluation method, based on the inverse heat transfer problem, was proposed. This method determines the thermal decay function of heat feedback through the insulation material and steel plate. By establishing three key performance indicators, this work achieved independent quantification of potential thermal concerns and robustness evaluations of steel structures with surface-bonded insulation materials under combustion.