Research On Adaptability Of Fire Helmet And Protective Clothing In The Long-term Temperature Thermal Radiation Environment

The basic guarantee for emergency rescue operations is that emergency rescue equipment realize design functions in long-term heat radiation environment,while the performance of fire-fighting helmets and fire-fighting protective clothing is reduced in the long-term heat radiation environment,which seriously threatens the lives of rescuers.Therefore,it is necessary to systematically explore the performance changes of fire-fighting helmets and fire-fighting protective clothing under thermal radiation environment.In this paper,a variety of measurement methods are used to study the performance changes of fire helmets and fire protection protective clothing,and the changes of internal and external temperature rise under different heat radiation fluxes.The performance changes under different heat radiation fluxes are used as the evaluation matrix to build a fault tree,to obtain the failure analysis of fire helmet and protective clothing,and then use analytic hierarchy process and fuzzy mathematics method to qualitatively and quantitatively evaluate the adaptability of fire helmet and protective clothing under different heat radiation flux.By controlling the heat flux of the fire helmet,the study of the performance changes and the material structure differences on the internal temperature rise can be obtained.After long-term low-flux heat radiation,the heat radiation resistance and optical properties of the fire helmet mask have no significant changes,and the hardness is attenuated by about 70%within the gradient of 30～220℃.Radiant heat flow at 10 k W/m~2 after heating for 10 minutes,the heat resistance and combustion resistance of fire helmets are lower than the index requirements.After the fire helmet is filled with a foam polyether buffer layer,under the continuous action of the top heat source,the maximum temperature in the helmet can be reduced by 24%.However,the changes of the exposure position of the heat source have no significant effect for the helmet’s temperature rise rate.By controlling the heat flux of the protective clothing,the performance changes of the protective clothing and the difference in structural thickness on temperature rise rate are studied.Long-term high-flux heat radiation has a significant impact on the thermal insulation ability of fire protective clothing,but there is no significant change in fabric breaking strength,flame retardancy,thermal stability,and liquid permeability.Under the same heat flux,when the thickness of different structures increases,the rise rate of the internal temperature decreases,but the final temperature changes with heating time tend to be consistent.An evaluation matrix is built based on the research results of performance changes in fire helmets and fire protective clothing,and use a variety of risk assessment methods to quantitatively evaluate the adaptability of fire helmets and fire protective clothing under different heat fluxes.The heat flow condition of 10 k W/m~2 heated to 10 min seriously impairs the performance of the fire helmet,while the fire protective clothing can still provide basic protection even under the heat flow condition of 10 k W/m~2 heated to 30 min.