Application of Smart Windows Equipped with Radiant Internal Curtains to Improve Thermal Comfort in Urban Transport Vehicles

In this work the application of radiant curtains in a train composition, for improving thermal comfort conditions, in winter season, is made. In this study the train compositions consider one occupied space with 32 passengers. The evaluation of thermal comfort conditions, using the Predicted Mean Vote index, is made by the Human Thermal Modelling numerical model. This model, that works in transient conditions and simulates simultaneously a group of persons, considers the body divided in 24 cylindrical and 1 spherical element, each element is divided in 4 parts and each part sub-divided in several layers. The body is protected by several clothing layers. This numerical model considers the human body and clothing thermal system, based on mass and energy integral equations system, the human body thermo-regulatory system, the heat exchange between the body and the environment and thermal comfort. The numerical test, when the train is subjected to solar radiation in the right side, is made with internal curtains. In these simulations tests are considered a uniform convective environment without significant air velocity, the internal air temperature, the air relative humidity and the Mean Radiant Temperature that each body element are subjected calculated numerically. In accordance with the obtained results, the internal warm curtains guarantee, in general, internal acceptable thermal comfort conditions.