Papers by Keyword: Solar-Thermal

Abstract: Thermoelectric power generation technology has been recognized to contribute to the realization of environment-friendly society all over the world in the future. Present status and future prospects on the thermoelectric power generation technology in Japan are overviewed. The thermoelectric applications for power generation have been mainly considered to be one of the waste heat recovery systems from industrial, private, and transportation sectors in the Japanese energy system. Such activities have been in progress in Japan. Then, several demonstration system tests and feasibility study have been achieved using practical heat sources such as industrial furnaces, motorcycles, solid waste incinerators, and solar thermal systems have been achieved mainly by private companies. Several topics of experimental results on advanced modules based on layered oxides, Heusler alloys, filled Skutterudites for power generation from the view points from environment-friendly and nanostrucuture approach are included. In the future prospects the recent R&D projects of advanced materials for thermoelectric power generation technology and the commercialization of thermoelectric power generation applications are discussed.

Abstract: Consideration of technologies for the use of concentrated solar power (CSP) leads to the conclusion that there is substantially more energy in the sun’s heat than there is in its light. At present, solar-thermal energy conversion and storage systems using CSP have the shortcomings of the use of high pressures and potential problems with corrosion. In the development of new materials and designs, two of the key issues of consideration are the: (a) thermal properties of the materials and (b) heat transfer within the system. Most current technologies utilise convective heat transfer of liquids but there are none that use conductive heat transfer with solid-state systems. The present work introduces such a system in the form of highly dense and aligned self-assembled graphite, which can be heated in air, provided the hot face temperature is at a temperature sufficiently low to avoid the onset of oxidation. Modelling of a small domestic-scale system, which has no competition in the marketplace, consisting of: (a) 4 m diameter concentrator, (b) block of graphite weighing ~160 kg, and (c) electricity generation system demonstrates that, in only 90 min and at ≤420°C, sufficient heat can be stored to supply 25% more than is required for a typical 24 h, domestic, electricity usage cycle.

Abstract: Thermal energy storage is an essential advantage of solar thermal power plants. The present paper focuses on latent heat storage using a phase change material (PCM). The paper lists literature and gives the current status of PCM work in the temperature range 200 to 350 °C. The system KNO3-NaNO3 is discussed in detail in terms of their thermo-physical properties in the liquid and solid phase. A comparison of literature data and own measurements for the density, heat capacity, thermal diffusivity and thermal conductivity is presented. Measurement results with the following methods are discussed: helium pycnometer, differential scanning calorimeter (DSC) and laser flash. Missing data of the thermal diffusivity and thermal conductivity are partly supplemented. Consistent thermo-physical properties in the liquid phase are presented.