Alvaro de Gracia

Study of the Thermal Properties and the Fire Performance of Flame Retardant-Organic PCM in Bulk Form

The implementation of organic phase change materials (PCMs) in several applications such as heating and cooling or building comfort is an important target in thermal energy storage (TES). However, one of the major drawbacks of organic PCMs implementation is flammability. The addition of flame retardants to PCMs or shape-stabilized PCMs is one of the approaches to address this problem and improve their final deployment in the building material sector. In this study, the most common organic PCM, Paraffin RT-21, and fatty acids mixtures of capric acid (CA), myristic acid (MA), and palmitic acid (PA) in bulk, were tested to improve their fire reaction. Several flame retardants, such as ammonium phosphate, melamine phosphate, hydromagnesite, magnesium hydroxide, and aluminum hydroxide, were tested. The properties of the improved PCM with flame retardants were characterized by thermogravimetric analyses (TGA), the dripping test, and differential scanning calorimetry (DSC). The results for the dripping test show that fire retardancy was considerably enhanced by the addition of hydromagnesite (50 wt %) and magnesium hydroxide (50 wt %) in fatty acids mixtures. This will help the final implementation of these enhanced PCMs in building sector. The influence of the addition of flame retardants on the melting enthalpy and temperatures of PCMs has been evaluated.

Static Concept at University of Lleida

Abstract This chapter presents the main results and conclusions obtained during experiments with different phase change materials (PCMs) carried out at the laboratory and pilot plant facilities at the University of Lleida since 2008. Regarding the laboratory analysis, it was observed that the dimension of the sample had a big influence on the range of phase change and on the appearance of the subcooling effect. Regarding the pilot plant analyses the study focused on a number of areas. First the influence of the heat transfer fluid (HTF) flow rate was studied. Results showed the importance of achieving turbulent behavior with the HTF. Second the influence of adding fins was investigated. They can be a powerful tool for partial charging or discharging processes. Third the influence of the thermal energy storage (TES) containers was studied. A poor design of the TES containers, with the presence of PCM dead volumes within the vessel, reduces the efficiency of thermal processes.