Abstract:

Significance In high-temperature environments during the summer and high heat scene, workers' body core temperature keeps rising, leading to heat stress issues such as heat exhaustion, heat stroke, and heat cramp. Individual cooling garment are capable of mitigating heat stress issues that workers may experience in high-temperature environments. By regulating the temperature inside the clothing, they enhance the comfort of the wearer and improve their work efficiency. These suits serve as effective protective equipment with notable cooling effect. Traditional individual cooling garment face key issues such as short cooling duration, hot and humid when worn, and coolant leakage. The emergence of new cooling systems has provided research directions for improving cooling garment. Based on the latest research findings, the classification of cooling garment from a cooling system perspective has been introduced. The latest cooling system designs have been summarized, and the main factors influencing cooling garment performance have been analyzed. Additionally, the future development trends have been outlined with the aim of providing reference for the research and development of cooling garment.
Progress It is crucial to develop new cooling systems and find solutions to enhance the comfort of cooling garment. Researchers have conducted extensive studies to improve cooling systems, aiming to enhance cooling effectiveness and refrigeration efficiency. In the field of gas cooling garment, researchers have compared the impact of garment size and ventilation rate on thermal resistance and cooling effectiveness. The results indicate that loose-fitting gas cooling garment exhibit superior ventilation efficiency and cooling effectiveness compared to form-fitting suits. To address practical applications, researchers have developed gas cooling garment with adjustable fan speeds. The results demonstrate that incorporating fans both in the front and back of the garment not only improves comfort but also reduces energy waste while maintaining longer cooling effects. In the field of liquid cooling garment, the latest approach for pipe preparation involves using PU fabric and heat pressing techniques to create cooling pipes. Liquid cooling garment designed with semiconductor refrigeration devices have effectively addressed coolant leakage issues and improved thermal comfort for wearers. Regarding pipe layout, research indicates that transverse arrangement of cooling pipes yields higher cooling efficiency compared to longitudinal arrangement. In the field of phase-change cooling garment, multiple studies have shown that increasing the temperature difference between the cooling pack and the environment improves cooling efficiency. Therefore, scholars have developed hybrid cooling jackets using dry ice and fans, resulting in improved refrigeration efficiency, extended cooling duration, and easier cleaning of the cooling garment. In the development of new cooling garment, thermoelectric refrigeration systems are gaining attention. These systems do not require compressors and allow for quick and accurate adjustment of cooling efficiency by regulating electric current. The temperature range that can be controlled is wide (-130 ℃ to 90 ℃), and there is no risk of refrigerant leakage with semiconductor cooling plates. Radiative cooling is another research direction of interest. Nanofabricated silk cooling garment based on radiative cooling principles can lower skin temperature by 8 ℃ in high-temperature environments, meeting comfort requirements. Furthermore, it is essential to develop new materials that offer excellent wearer comfort, high cooling efficiency, and enhanced environmental sustainability for new cooling systems. Examples include temperature-sensitive shape-memory bacteria and nanoporous polyethylene materials. Addressing the portability issues of convection-based gas cooling garment and insufficient power supply for cooling devices, a vacuum desiccant cooling (VDC) system has been developed. VDC pads are prepared and initialized by a high-performance vacuum pump, with the vacuum layer facilitating evaporation for cooling effects.
Conclusion and Prospect The development of cooling clothing in the future is mainly reflected in the research and development of green functional fabrics with good cooling effect, and in optimizing the packaging of the cooling medium to reduce energy waste. The future development of cooling clothing is mainly reflected in the development of green functional fabrics with good cooling effects and new lightweight and durable materials. The following are believed to represent the research directions: optimization of the packaging of cooling medium to reduce energy wastel; further research and development of automatic adjustment heat exchange network to improve wearing comfort; more comprehensive ergonomic evaluation of cooling garment, taking into account the thermal perceptual response and ergonomics and other factors to improve the performance of cooling garment, and development of more intelligent, simple, miniaturized intelligent temperature control system.

Key words: functional clothing, cooling garment, heat stress, thermoelectric cooling system, radiation cooling system, new material cooling system