Preparation And Properties Of Binary Organic/Inorganic Nano-composite Phase Change Materials For Thermal Energy Storage

The depletion crises of fossil energy and environmental problems have been paid to more and more attention; to improve energy efficiency and develop renewable energy is an important task that we are facing.Thermal energy storage is an important means of improving energy efficiency, thermal energy storage can be used to solve conflict that the heat do not match between supply and demand in time and space. Through the thermal energy storage, thermal energy unused temporarily or redundant can be stored for use when it required. Latent heat thermal energy storage is one of the important ways of thermal energy storage, it can be traced back to ancient times about the application in daily life, but the rise and development of the basic theory and applied research of the phase change thermal storage only have several decades of history. In recent years, research and application of phase change thermal storage have been developed rapidly. In this area, compared with some developed countries, our research is still weak relatively, especially in applied research, there are still many problems to be resolved.First, in this paper, organic solid-liquid phase equilibrium is discussed and analyzed, and the solid-liquid equilibrium phase diagram, phase transition latent heat and energy-saving effects were measured for the solid-liquid phase change materials, which provided a simple screening and viable method of operation.Second, in this paper, as the organic phase change materials' weaknesses and deficiencies in, carried out the binary composite system. According to the theoretical principles of freezing point depression, we have adopted a step cooling curve determined lauryl alcohol-fatty acids, fatty acids-fatty acids in binary solid-liquid equilibrium relationship, drew some T-X phase diagrams of these systems. The results indicated that several groups of binary mixtures are simple eutectic systems; combined with DSC analysis at the same time, confirms the eutectic composition, phase transition temperature and phase transition enthalpy of the binary composite systems. The results show that the phase transition temperatures of the mixtures that are low melting point of the phase transition are in the required temperature range.Third, we used quaternary ammonium, triethanolamine, amino acids and other non-reactive organic modifier to modify clay organically and studied and explored the optimal conditions for the experiment. The best experimental conditions of preparation from inorganic modified clay to modify clay were: clay concentration is 5%, stirring time is 2.5h, modified temperature is 55℃, organic modifier/clay mass ratio is 0.70.Fourth, we prepared binary organic/inorganic nano-composite phase change thermal energy storage materials by intercalation compound method, and studied its preparation process conditions systematically; and carried out its analysis of the structure and performance characterization by using X-RD, FT-IR, SEM, TEM, DSC, TG, TC, etc. The results obtained show that composite phase change thermal energy storage materials, superior performance, better overcome the pure phase-change thermal energy storage material weaknesses and deficiencies. And a simple modification of the binary organic/inorganic nano-composite phase change thermal storage materials is discussed preliminarily.Finally, we prepared binary organic/inorganic nano-composite phase change thermal storage materials; the various influencing factors of thermal storage capacity are discussed. The best experimental conditions for preparation of organic/inorganic nano-composite phase change thermal storage materials were: organic matter content is 55%～60%, preparation of compound time is 5h, Preparation of composite temperature is 70～80℃, grain degree of composite phase change thermal storage materials is 60～120 mesh.