LAUSR

Abstract The enormous amount of heat in fires can bring the inhaled air temperature to an extremely high level, which is fatal to the civilians. However, conventional rescue respirators are unable to control the breathing air temperature. In our previous work, a phase change material-based heat exchanger has been designed to cool down the inlet air from 500 K to a breathable 313 K and sustaining for more than 20 min. As a part of wearable respirator, its wearing comfort must be considered by minimizing its pressure drop and keeping it lightweight. Hence, the design is modified by proposing a cooling module with twin heat exchangers and the structural design of the heat exchangers is optimized by response surface methodology and multi-objective genetic algorithm. The optimized design can offer the required cooling performance with up to 65% lower breathing resistance and 30% lighter weight, which is beneficial for the further applications.