Aislantes para la construcción con inclusión de materiales de cambio de fase

Abstract

The authorities of most of the countries are currently developing regulations and laws aimed at achieving greater environmental sustainability. In the case of Architecture there is the challenge of achieving buildings with CO2 emissions and energy consumption zero or nearly zero. The objective of this work is to make an advance in this challenge, managing to reduce the transmission of heat through the walls of the buildings. Several conventional insulation materials have been studied, to which micro-encapsulated Phase Change Materials have been added as a filler. Sandwich panels are proposed, in which materials "enriched" with PCMs are protected with outer layers of conventional insulation materials. This system is based on night-day cycles (cooling-heating) and heat transfer through the walls. According to the temperature gradient between the interior and the exterior, there will be an incoming or outgoing heat flux depending on the case, when these heat flux touch the layer treated with PCMs, they will solidify or melt maintaining the temperature during the phase change. In ideal conditions, it achieves enclosures with zero thermal conductivity, that is, totally insulating to the passage of the heat. The reality is that the day-night cycles are not symmetrical with respect to the setpoint temperature in the interior, so the ideal answer of the system will not be achieved every day. In order to demonstrate the objectives of this work, it has been necessary to develop methods of measurement of heat transfer and theoretical models. Also, the symmetry has been determined in the fusion-solidification process of the PCMs studied. In order to consider a real case that limits the system, the energy saving achieved during 1 year in Murcia was compared betwen a traditional insulation and the designed sandwich panel. In Murcia, climatological conditions have very hot summers, where the interior setpoint temperatures are lower at all times at both day and night temperatures, which means that the efficiency of the proposed system is greatly reduced. Even so, the result achieved is an energy saving of more than 40% compared to the traditional one. Being close to a total saving in the most favorable months. It is concluded that the new technology developed demonstrates that PCMs can be used, not as a heat storage system, but also a dynamic thermal barrier with successive cycles of accumulation and heat transfer. The system developed can be used for other applications, in which the cold-heat cycles are accurate and ideal, in this case the new technology is superior to the super-insulators because it leads to a heat transfer equal to zero.