For industrial effective use of low-density energy such as factory exhaust heat or solar heat utilization, development of large heat storage with fast heat exchange technology is required. Especially in cold regions such as in Hokkaido, the demand for heat in winter is large, and attempts to use large-scale, high-temperature unused waste heat from steel manufacturers and pulp factories to medium temperature zones such as hot water supply and air conditioning will become increasingly important in near future. Also, in automobiles and factories, the heat engine needs to be cooled during operation and must operate within a certain temperature range. However, if the heat engine is cooled down after it is stopped, it must be heated again as it restarts. Therefore the technology to suppress the temperature drop of the system by the application of heat storage and regeneration technology is expected. Previously, water or aqueous liquids were used for heat storage with heat exchange to suppress temperature drop of the system, however, only the sensible heat can be used for heat storage. For else, polymer phase change substances are used instead. However, high heat transfer characteristics could not be obtained as for their poor fluidity. This paper reports on the thermal properties of phase change emulsions as functional fluid that have both heat storage and fluidity for heat exchanging, moreover, basic characteristics of heat sinks modelled by metal powder additive manufacturing using a copper alloy with high thermal conductivity for the system application.

An Active Magnetic Regenerator (AMR) cycle that employs magnetocaloric materials (MCMs) as regenerators is generally used to realize the effective temperature span for magnetocaloric heat pump systems. The MCMs of the first-order phase transition materials have gained attention because of the latent heat involved in their phase transitions. However, because the range within which the MCM exhibits an magnetocaloric effect (MCE) is narrow near its Curie temperature, only a narrow temperature span exists in the case of the AMR with a single MCM. Therefore, there is a demand for the AMR system with material layers made of a couple of MCMs. However, only few studies have investigated the influence of the properties of MCMs on magnetocaloric heat pumps using material-layered systems. In the present study, the refrigeration capacity and the temperature span of the magnetocaloric heat pump with a material-layered bed of manganese-based compounds, which are first-order phase transition materials, were determined. It was found that the temperature span can be extended by optimizing the volumetric flow rate and the number of the layers that constitute the AMR. In addition, the number of the layers and the refrigeration capacity were found to be related.