Xu X, Hexamer M, Werner J
Department of Biomedizinische Technik, Ruhr-Universität, Bochum, Germany.
Ergonomics. 1999 Feb;42(2):282-98. doi: 10.1080/001401399185658.
In this study the effects of multi-loop control of liquid cooling garments (LCGs) under exercise heat stress conditions were investigated by experiments and theoretical analysis. A triple-loop LCG, by which the torso, arms and legs could be independently cooled, was used in the two series of experiments carried out in a hot environment (35 degrees C/40% RH). The experiment consisted of rest, exercise on an ergometer at 70 W and exercise at 110 W. In the first experiment, each water inlet temperature (TWI) was adjusted according to the local thermal sensation. In the second experiment, TWI for the torso including arms and TWI for the legs were regulated by a skin temperature controller with set-point adjustment via heart rate. The experiments showed that a multi-loop LCG is more effective than a single-loop LCG in providing thermal sensation and comfort adjusted to the requirements of the different parts of the body, and that a skin temperature controller could be applied to a multi-loop system. The theoretical analysis was carried out using a mathematical model of thermoregulation. The results showed that a strong cooling of the surface over the working muscles (legs) provided the greatest thermoregulatory advantage during low body exercise, because most of the heat generated within the working muscles can be removed directly by heat conduction to the skin. Optimization of a human/LCG system could be attained by an optimal configuration and control. However, an optimal configuration always depends on the application purpose of an LCG system.
在本研究中，通过实验和理论分析，研究了运动热应激条件下液体冷却服装（LCG）多回路控制的效果。在炎热环境（35℃/40%相对湿度）中进行的两组实验中，使用了一种三回路LCG，通过该装置可对躯干、手臂和腿部进行独立冷却。实验包括休息、在功率计上以70W进行运动以及以110W进行运动。在第一个实验中，根据局部热感觉调整每个进水温度（TWI）。在第二个实验中，通过心率调整设定点的皮肤温度控制器来调节包括手臂在内的躯干的TWI和腿部的TWI。实验表明，多回路LCG在提供适应身体不同部位需求的热感觉和舒适度方面比单回路LCG更有效，并且皮肤温度控制器可应用于多回路系统。使用热调节数学模型进行了理论分析。结果表明，在低强度身体运动期间，对工作肌肉（腿部）表面进行强力冷却具有最大的热调节优势，因为工作肌肉内产生的大部分热量可通过热传导直接传递到皮肤而被去除。通过优化配置和控制可以实现人体/LCG系统的优化。然而，最佳配置始终取决于LCG系统的应用目的。
