人体运动状态下热防护服的蓄放热双重效应作用机理及皮肤烧伤预测

Skin burns of occupational operators easily occur when they are doing exercise under thermal hazardous environments. Thus, a breakthrough to the traditional research on thermal protective clothing conducted under static conditions and the reveal of its dynamic protective mechanism under human motion conditions have become the key issues for effective prevention of skin burns. To study the thermal protective mechanism under human motion conditions and implement the scientific prediction on skin burn injuries, this research conducts both laboratory experiment and numerical simulation through taking an entry point that the thermal protective clothing has a dual effect due to its heat storage-release property. Firstly, a dynamic test is performed to examine the heat storage-release property of the fabric when the characteristics of dynamic microclimate air gap size, fabric tension and compression deformation are all taken into account. The change rules and the influencing factors of heat storage-release property are investigated. Secondly, a heat transfer model of the system that consists of the thermal radiation environment, the thermal protective fabric with deformation, the dynamic air gap and the skin is established. The temperature field and heat flow distribution of the system are analyzed. The interaction among radiative and convective heat from the environmental, heat storage and release of the fabric, and heat gain of the skin is revealed. Finally, a computerized iteration model is developed to predict different degrees of skin burns. The relationships between heat storage-release property of the fabric system and skin burn injuries are established. The outcomes of this research will improve the theory of the dynamic protective mechanism of thermal protective clothing, and provide scientific guidance for the development of high-performance thermal protective clothing and the prediction of skin burns.

热灾害环境中作业人员在运动时更易发生烧伤，因此突破人体静态条件下的热防护服传统研究，揭示其在运动状态下的热防护机制，成为有效预防皮肤烧伤的关键。本项目将以热防护服在热暴露与冷却阶段的蓄放热双重效应为切入点，利用传热实验和数值模拟开展人体运动状态下的热防护机理研究，实现皮肤烧伤的科学预测。研究中首先综合模拟人体运动时衣下空间尺寸的连续性变化、织物拉伸与挤压形变状态，进行织物蓄放热特性的动态测试，明确织物系统蓄放热双重效应的变化规律及影响因素；其次建立高温热辐射环境中由形变状态下织物、动态衣下空间及皮肤所组成系统的传热模型，解析系统内的温度场及热流分布，揭示环境辐射热与对流热、织物系统蓄放热以及皮肤得热的相互作用规律；最终构建计算机迭代模型实现不同等级的烧伤预测，阐明织物系统蓄放热特性与皮肤热损伤的关系。研究成果将完善防护服的动态热防护理论，为高性能热防护服研发及皮肤烧伤预测提供科学指导。

针对运动状态下热防护服防护机理尚不明晰的问题，本项目从传热实验和数值模拟两个层面系统地开展了热防护织物对人体皮肤的蓄热防护与放热危害双重效应的基础研究，从皮肤烧伤预测的角度实现了热防护织物蓄放热双重效应的综合评价。.在传热实验研究方面，研制了热防护织物蓄放热特性测试仪，动态考察了热暴露与冷却阶段各织物层的温度及皮肤得热，考察了由于运动导致的织物拉伸形变、挤压形变以及衣下空气层厚度变化等因素对热防护织物系统蓄放热特性及皮肤得热的影响规律，解析了织物系统蓄放热与皮肤得热波动的关系。在数值模拟研究方面，综合考虑了运动过程中的织物拉伸与挤压形变特征，构建了形变状态下热防护织物、衣下空气层、人体皮肤在热暴露与冷却全过程的传热模型，研制了织物拉伸夹具用于获取形变后织物的厚度、密度、导热系数等重要物理参数，利用传热实验对数值模型的准确性进行了验证，全面解析了织物系统的蓄放热对皮肤热响应的调控机制。在皮肤烧伤预测研究方面，构建了以计算机迭代模型为代表的多种新型织物综合热防护性能评价方法，将计算机迭代模型分别与热防护织物系统的传热实验与数值模型相耦合，突破了现有“物理迭代实验法”操作繁琐、效率低的缺陷，为皮肤烧伤评估提供了多元化方法。在此基础上，研究了织物的拉伸形变、挤压形变、热暴露时间、热源距离等因素对不同等级皮肤烧伤的影响。.本研究增进了对热防护服着装人体由于运动易导致皮肤烧伤的科学认识，为相关测试标准和评价方法的制定提供了参考，为高性能热防护服装的研发及科学预测皮肤烧伤提供依据与指导。