Modeling And Simulation Of Heat And Moisture Transfer In PCM Clothing & Influences On Human Thermal Responses

To investigate the thermal properties of garment with phase change materials (PCM) microcapsules, a new mathematical model to describe heat and moisture transfer in fabric with single-type PCM is developed based on the mass and energy balances. The heat exchange among the PCM microcapsules and textile, the radiation, the moisture sorption/desorption by the fibers and interaction between the heat and the moisture are considered in the model. And the governing equations are solved by using the control volume method. Meanwhile, the theoretical predictions are compared with experimental data. The result indicates that the model is satisfactory. The new model is used to simulate the humidity of the environment's influence on the textile's heating and humidity transferring. Then, the model of heat and moisture transfer in clothing with multi-type PCM microcapsules is developed. And the influences of multi-type PCM microcapsules on thermal properties of the garment are studied. Finally, the heat and moisture transfer in human body-clothing-environment system is developed by combining the improved 25-node human thermal regulatory model and PCM clothing model. Also, the influences of PCM content, distribution in clothing and contact state on human thermal responses is studied by using the above mentioned model.The conclusion shows that: (1) The relative humidity can effect the role of PCM microcapsules significantly; When the temperature difference is smaller, the radiation of the model can be ignored. (2) The PCMs have the function to delay the clothing temperature and humidity variation. The more PCM content, the better delaying is. Adding multi-type PCM microcapsules can complete multi-step delay and extend the regulation range. (3) The human skin temperature rising can be delayed by clothing with PCM, and the PCM microcapsules distributed in the outer layer of clothing are better than that in the inner layer. The effect of contact clothing layers is better than that no contact clothing layers in delaying skin temperature rising and decreasing sweat accumulation.