Liquid cooling garment for personal protective ensemble : modeling and simulation

Personal protective ensembles (PPE) are required for people exposed to hazard, which may prevent heat dissipation from the human body, leading to suffering from heat stress. To protect the PPE wearer from heat stress, a liquid cooling garment is widely accepted to provide personal cooling inside the PPE. For an impermeable PPE or a high humid environment, sweat evaporation is also prevented, and moisture accumulation may lead to discomfort. It is important to make sure that the liquid cooling garment removes enough heat to suppress sweat while not over-cooling the wearer. A thermoregulatory model was introduced and modified, in which the human body is divided into six parts, including the head, trunk, arms, hands, legs and feet. A whole/partial liquid cooling model, formed with a network of tubing, is developed. A thermal resistance network for the tubing system is built up and the control volume method is employed to carry out the numerical calculation. The liquid cooling model, thermoregulatory model and heat/mass transfer involved are integrated into one model, which can simulate a PPE wearer thermally interacting with the water cooling system, predict the physiological responses and ensure the wearer is free of heat stress. The mathematical model is verified by comparing its simulation results to experimental data from other researchers. This model is to be used to provide guidance to properly choose PPEs in various conditions