关键词: 智能温控系统, 防寒手套, 手部舒适性, 皮肤温度, 冷接触

Abstract:

Objective When working in a cold environment, people usually wear intelligent cold-proof gloves to compensate the lack of physiological heat regulation. The previous studies on electric heating gloves showed that there had been no temperature regulation based on skin temperature, and it was difficult to control accurately the heating pad. In addition, there had been few studies regarding simulation of the real operation of pressure states for cold contact state. In this research, a temperature-control system was designed and the thermal comfort performance of the cold-proof gloves was targeted for investigation.
Method The designed intelligent temperature-control system rapidly adjusts the heating power of the heating pad by comparing the skin temperature with the comfortable temperature of the human body. The skin-simulant sensor of the cold-contact test device was used to measure heat transfer through fabric system. The skin temperature changes during the cold contact were analyzed to explore the influence of modes of temperature control, heating temperatures, fabric layers and cold contact conditions on the thermal comfort performance of the cold-proof gloves.
Results As for the heating effect of the intelligent cold-proof gloves, skin discomfort, even frostbite occurred for no heating pad (Fig. 4). However, when the intelligent heating pad was used, the skin temperature was more stable. In terms of design factors of heating pad, when the mode of temperature control for human skin (STC) was adopted, the final skin temperature was stable around the comfort range. Compared with the mode of temperature control for the heating pad (HPTC), the skin temperature was more stable and closer to the comfortable temperature range (Tab. 4). At the same time, the temperature of the heating pad was reduced to a certain extent on the premise of ensuring the thermal comfort of the skin. Therefore, energy consumption was considered to be effectively reduced (Fig. 6). In an extremely low temperature environment, the intelligent heating pad greatly improved the thermal comfort performance of the gloves and reduced the number of fabric layers, meeting the requirements of skin comfort and flexible operation (Fig. 7). With decrease of the contact temperature, the physiological discomfort was aggravated and the time to reach the skin discomfort gradually became shorter (Fig. 8(a)). After using the heating pad, the final skin temperature is basically stable within the comfortable temperature range of the skin, which ensures the long-term thermal comfort requirements of the skin (Fig. 8(b)). The final stable skin temperature was higher for 0 kPa pressure than that for 3 kPa pressure. When the heating pad was used, the change of the skin temperature was contrary to no heating pad. Besides, the skin temperature was higher for 3 kPa pressure than that for 0 kPa pressure (Fig. 9). However, the intelligent heating pad for the double-layer fabric system worked to maintain the skin temperature and ensure the skin thermal comfort under 0 kPa and 3 kPa pressures.
Conclusion An intelligent temperature control system was developed and the influence of heating pad design and fabric layer number on skin temperature change in different cold contact conditions was investigated based on the cold-contact test device of fabric. The designed intelligent cold-proof gloves with the STC mode can keep the skin temperature stable in the comfortable temperature range during cold contact. Two modes of temperature control for the heating pad (HPTC) and human skin (STC) were compared, considering the thickness, temperature control and power consumption, and the STC mode seems to be the better heating choice. With the increase of fabric layers, the thermal comfort performance of the intelligent cold-proof gloves is improved. However, according to the different fabric layers, the intelligent cold-proof gloves with skin temperature control mode can achieve thermal comfort. Furthermore, the intelligent cold proof gloves can keep the skin temperature in the comfortable temperature range under different experimental pressures to ensure the thermal comfort of the skin.

Key words: intelligent temperature-control system, cold-proof glove, hand comfort ability, skin temperature, cold contact