The heat and moisture transfer model of firefighter protective clothing

This paper presents a model of heat and moisture transfer through multilayer firefighter protective clothing, which for the first time has taken into account all the major heat and moisture transport mechanisms including conductive and convective heat transfer, two-flux radiative heat transfer, moisture bulk flow, moisture absorption/desorption by fibers, moisture diffusion and phase change. The model was solved by Crank–Nicolson scheme of the finite difference method. Numerical analysis showed that our model can accurately predict the second-degree burn time with an error ranging from 0.37% to 3.55% for different types of clothing assemblies. With this model, the distributions of heat and moisture within the protective clothing system are elucidated and the relative importance of key clothing parameters on thermal protection better understood. It revealed that the thickness of the moisture barrier layer has the greatest influence on the skin burn time. This study is significant in providing a theoretical framework for optimizing the design of thermal protective clothing.