Preparation Of Low Temperature Phase Change Materials Used In Hvac

With the development of science and technology and the improvement of people's life, the mismatch of energy supply and demand is becoming more and more serious. In order to overcome the mismatch, the energy storage technology with phase change emerged. During the process of phase change, the materials can absorb or release energy, which can match the energy supply and demand.Materials for energy storage used in HVAC systems have the phase transition temperature range in low-temperature range, therefore, it's significant to study the low-temperature PCMs to solve the energy problem. fatty acids and hydrated salts usually are the ideal candidates for the low-temperature energy storage system.First, the phase transition temperature curve of the binary mixture was obtained through the experimental investigation to capric acid and lauric acid by T-history method. Based on the experimental data and theoretical data, the eutectic melting point is between 19℃~20℃, when the proportion of capric acid is between 0.66~0.7.We also studied on their thermal conductivity improvement by adding graphite powder.Second, the optimal amount of nucleating agent for aluminum potassium sulfate was found by the experimental investigation. The research on phase transition temperature, the degree of supercooling and latent heat after thermal cycles was carried on by T-history method and DSC method. At the same time, the thermal conductivity improvement experiment of aluminum potassium sulfate by adding graphite powder was carried on, and the results showed that the addition of graphite powder id mechanically mixed, and with the increase of the amount of graphite powder, the thermal conductivity increases.Finally, based on the existing applications, some improvements were put forward to. The production resulted from the above experimental researches will provide the necessary experimental data and technical support for the application in HVAC systems.