Phase Change Materials and Power Engineering

The review contains information on the properties of phase-change materials (PCM) and the possibilities of their use as the basis of thermal energy storage. Special attention is given to PCMs with a phase transition temperature ranging between 20 and 80°C since such materials can be effectively used to reduce temperature variations in residential and industrial rooms. Thus, the application of PCMs in the construction industry enables one to considerably reduce the power consumption and reduce the environmental impact of industrial facilities. Thermophysical characteristics of the main types of PCMs are presented. The heat balance for a room with walls made of PCM-added materials is estimated. The predictions demonstrate that such structures can stabilize the temperature in practical applications as a result of usage of such materials. The potential of wide application of PCMs as a basis for thermal energy storage is limited due to very low conductivity (less than 1 W/(m K)) specific for these materials. Hence, the option of increasing the material conductivity by adding some carbon nanotubes whose thermal conductivity is four to five orders of magnitude greater than that of the base material is examined. The numerical predictions of the heat-conduction enhancement in a PCM doped with carbon nanotubes and the preliminary experiments indicate that a PCM with approximately 20% carbon nanotubes can enhance the material heat conductivity by two to four times.