Development of a full-scale apparatus to assess thermal protective performance of garments under highly intensive heat flux exposures

Abstract

This study discusses the development process of a full-scale test facility composed of a high-performance radiant heating system, a life-sized instrumented thermal manikin system with sensing assemblies, associated equipment and in-house software controlling the entire system. This test system was aimed to be used to examine the behaviour of emergency-responder garments and subsequently to find weaknesses of turnout gears at critical thermal conditions greater than a standard 84-kW/m2-intensity, thereby contributing to improving the survival chance of firefighters who could be requested to execute an emergency evacuation from an unexpected growth of modern fires. To impose a target 126-kW/m2-irradiance throughout the garment-dressed manikin’s exposed surface for a limited period of time (12 s) as uniformly, consistently, stably and safely as possible, several technical aspects were considered: the amounts of heat-source power and electric power-supply; areas of heating and receiving and their geometrical relationship; a practical percentage of the maximum heater-capability; efficiencies of electric power-supply and water-cooling; movable equipment; and safety equipment. Two analytical models were encoded using a finite difference method in the LabVIEW platform to determine a burn injury distribution throughout the manikin-shell in association with the measurement data from the test system. The heating system and software were validated in respect of the heating consistency, vertical intensity variation, intensity-rise rate and discrepancies between the existing and present models. It was proved that the heating system is capable of increasing its heat emission up to 126 kW/m2 within 1.5 s, maintaining the intensity-level with less than 9-kW/m2-change for 12 s, and distributing the intensity-level with less than 11-kW/m2-variation along the vertical direction, from 45-cm- to 155-cm-height. The development process can contribute to the ability to develop a large-scale test facility to test specimens under a critical thermal exposure condition for research purposes.