The Study Of Phase Change Materials On Storing Energy

With the ever increasing energy needs, how to effective and rational utilization energy source have already become a problem people stringency concerned. In the course of phase transformation because phase change materials (PCMs) have got a great deal of energy storage and release, save energy , and approve actual effect of utilization, PCMs will be widely applied in the saving energy fields including the building, solar energy, exhaust heat, exhaust cool and so on.This article studied solid-liquid-equilibrium (S-L-E) of organic compound system, measured solid-liquid phase diagram, latent heat of phase change and energy conservation effect in order to supply a sort of simple, feasible means to choose solid-liquid PCMs.In experimental research, the S-L-E of eleven binary system including Fatty alcohol/ Fatty acid , n-Octadecane/Fatty acid, n-Octadecane/Fatty alcohol system were determined by cooling curve . At the same time, the S-L-E of one ternary system of n-Octadecane/Fatty acid/Stearic acid was measured by pseudo-duality , and T-X phase diagrams of these systems were drawn. The result shows that all these system are simple eutectic , at the same time, the entropy of phase change of every system in the eutectic point is determined by using differential scanning calorimetry (DSC)On the basis of experimental research , through the improved one-parameter Margules equation by introducing a new variable temperature, the improved equation was designed to compute solid-liquid equilibrium. We obtained the improved one-parameter Margules equation which can be applied to binary systems, such as Fatty alcohol/ Fatty acid system. The S-L-E experiment data for the eight binary condensed systems of Fatty alcohol/ Fatty acid were treated by using the improved equation, and the equation was examined with experimental data. At the same time, we used ideal model to predict the tenary S-L-E of n-Octadecane/Lauric acid/Stearic acid system, and we got an accurate result of the simple eutectic temperature. The relative error is 0.51% comparing with the experimental result, so we will offer a method of prediction for quickly obtaining multicomponent system phase change materialsThis article calculated the PCMs quantities and energy saving effect in theory , designed the experimental apparatus to measure the energy saving effect, and analyzed the temperature equalization action of the PCMs by comparing experiment. According to theexperimental result, by introducing PCMs to the building, the temperature fluctuation was buffered and the time of indoor comfort temperature was prolonged, at the same time, the energy storage course of PCMs has reversibility and continuity .Through the study , the phase change materials on residential storing energy was obtained whose melt point is 16 -28 C and heat of transformation reach or exceed 180j/g...