The connection between the heat storage capability of PCM as a material property and their performance in real scale applications

Using phase change materials (PCM) for Thermal Energy Storage, the most important material property is their heat storage capability, usually given as h(T). Ideally, h(T) changes suddenly at a single temperature. However, many PCM change phase in a temperature range and show hysteresis. In addition, experience shows that even measurements with the same device on the same material can give different results when the heating rate, the amount of sample mass or the equipment device are varied. The question thus arises how to deal with different h(T) results when trying to predict the performance of a real scale application. This paper identifies the main origins of these effects and gives strategies for dealing with them.The research leading to these results has received funding from the European Commission Seventh Framework Programme (FP/2007-2013) under grant agreement n° PIRSES-GA-2013-610692 (INNOSTORAGE) and from the European Union’s Horizon 2020 research and innovation program under grant agreement No 657466 (INPATH-TES). The authors would like to thank the Catalan Government for the quality accreditation given to their research groups GREA (2014 SGR 123) and DIOPMA (2014 SGR 1543). GREA and DIOPMA are certified agents TECNIO in the category of technology developers from the Government of Catalonia. This work has been partially funded by the Spanish government (ENE2015-64117-C5-1-R (MINECO/FEDER)). Dr. Camila Barreneche and Dr. Aran Solé would like to thank Ministerio de Economía y Competitividad de España for Grant Juan de la Cierva, FJCI-2014-22886 and FJCI-2015-25741, respectively

Viscosity properties of bimodal bitumen emulsions: new approach

The emulsions used in the manufacture of half warm asphat should contain very little water in their formulation. Conventional monomodal emulsions have a maximum dispersed phase concentration, ϕ, of 0.69. Recent research in this field is focused on the development of concentrated emulsions, ϕ = 0.70-0.74, or highly concentrated emulsions, ϕ >0.74. The concentrated or highly concentrated emulsions have little water in their formulation, <30%, but consequently have very high viscosities. This article summarizes the main conclusions related with the design, formulation and viscosity of bimodal concentrated bitumen emulsions. To formulate a bimodal emulsion is necessary to firstly manufacture two monomodal emulsion with a controlled drop size distribution from 1 and 5 μm respectively. These emulsions should be prepared with a system able to control the final drop size. In this study we have used the HIPR (High Internal Phase Ratio) procedure. The emulsions formulated in this paper are characterized by having viscosities up to ten times lower than their small monomodal size counterparts.The authors would like to thank the Catalan Government for the quality accreditation given to their research group GREA (2014 SGR 123). GREA is certified agent TECNIO in the category of technology developers from the Government of Catalonia. Dr. Camila Barreneche would like to thank Ministerio de Economia y Competitividad de España for Grant Juan de la Cierva, FJCI-2014-22886 and Núria Querol would like to specially thank Sorigue Company for giving her the opportunity to develop this study using its manufacture production plant equipped with the most advanced technology to develop this kind of emulsions