Study of ultra-light modular phase change cooling clothing based on dynamic human thermal comfort modeling

Phase Change Cooling Clothing (PCCC) is a promising wearable device, which can reduce thermal discomfort and health risks associated with high ambient temperatures. However, most of the existing PCCC are developed for special types of work, with long cooling time but heavy weight, which are not suitable for daily life and work. Therefore, this study proposes a novel ultra-light modular phase-change cooling clothing for short-term thermal discomfort in daily life and work. Firstly, based on heat balance theory, the heat transfer process of people wearing PCCC is modeled, and a calculation method for the minimum charge of phase change material (PCM) is proposed. The weight of the PCCC is only 1390g for keeping thermal comfort over 30 min. Then, the modular structure is proposed to make the PCM solidification more convenient and the optimal arrangement of the PCM modules is determined. Finally, the thermal comfort before and after wearing the PCCC in different scenarios were tested. The cooling effects are significant and the average skin temperature of the subjects decreases by 1.35, 1.10 and 1.78 ?C respectively after wearing the PCCC under three conditions of outdoor walking, indoor sitting and indoor walking. The proposed PCCC has the advantages of light weight, proper structure and good effect, which is suitable for people's daily life and work.