关键词: 被动调温服装, 智能纺织品, 个人热管理, 辐射降温

Abstract: Textiles play a vital role in human daily activities and social development. With the development of intelligent technology and the growing demand for clothing functionality, textiles with various new intelligent functions, such as temperature control, sensor monitoring and color change intelligence are favored by people. In order to reduce the energy consumption caused by space cooling, people hope that textiles can create a comfortable microclimate to regulate the temperature. Since temperature regulating textiles can effectively regulate the human body temperature and wear thermal and wet comfort based on the human body temperature regulation mechanism, they have been widely studied and developed in recent years. This energy-saving and diversified personal temperature regulation technology is called "personal thermal management" technology.
At present, textiles with personal thermal management performance can be divided into active temperature regulating textiles and passive temperature regulating textiles according to the energy source. Temperature regulating textiles can cool down or keep warm when connected to an external power source, which is "active". On the contrary, temperature regulating textiles can only rely on the characteristics of materials without additional energy, which is "passive".
The active cooling system refers to the system that uses gas or liquid as the cooling source. Under the condition of external power (such as electricity), the cooling source flows to absorb human heat to achieve the purpose of cooling. There are various liquid (gas) medium embedded cooling systems. Similarly, as for the active heating system, the heating source is driven by an external power source to keep warm, with the heating methods including electric heating, solar heating, chemical energy heating, and phase change material heating. Passive cooling system means that no additional energy is required for temperature regulation. The passive cooling methods mainly include reflection (radiation) cooling, infrared transparent cooling, phase change material cooling, etc., while passive heating methods include reflection (radiation) heating, reducing heat conduction, light heat conversion, etc. We mainly introduce passive thermal insulation clothing materials such as new clothing thermal insulation materials, reflective (radiation) materials, far-infrared emission materials and photo thermal conversion materials, passive cooling clothing materials such as conductive cooling materials, phase change cooling materials, reflective cooling materials, mid infrared high transmission (emission) radiation cooling materials, and double-sided temperature regulating clothing.
There are many kinds of passive temperature regulating clothing. Among various clothing materials, new temperature regulating clothing materials can achieve different radiant heat controls by changing the emissivity, reflectivity and transmissivity of the clothing, so as to regulate the clothing microclimate to achieve "all-weather" thermal comfort without consuming additional energy, that is, personal radiant heat management. Radiation cooling, radiation heat preservation and double-sided temperature regulating clothing materials have also become the focus of current research.
Advanced passive temperature regulating textiles rely on the heat transfer characteristics of the system and the structural design of the material. They do not need any external energy input to regulate the microclimate between the human body and the external environment, regulate the human body temperature, and maintain the thermal balance and thermal moisture comfort of the human body. In recent years, scholars at home and abroad have studied passive temperature regulating clothing materials from the aspects of temperature regulating materials, temperature regulating mechanism, clothing structure design, etc., and successfully applied the research results to the market. However, the development of passive temperature regulating clothing materials at this stage still faces many challenges, such as clothing responsiveness and durability, wearing safety and ecological health issues, and lack of implementation standards and comfort evaluation. In general, passive temperature regulating textiles have huge application potential and development space in the field of maintaining human thermal comfort. Therefore, the research on intelligent temperature regulating textiles still needs to be further deepened in order to create new intelligent textiles more quickly.

Key words: passive temperature regulating clothing, intelligent textiles, personal thermal management, radiative cooling