Applications of thermal energy storage to process heat and waste heat recovery in the iron and steel industry

The system identified operates from the primary arc furnace evacuation system as a heat source. Energy from the fume stream is stored as sensible energy in a solid medium (packed bed). A steam-driven turbine is arranged to generate power for peak shaving. A parametric design approach is presented since the overall system design, at optimum payback is strongly dependent upon the nature of the electric pricing structure. The scope of the project was limited to consideration of available technology so that industry-wide application could be achieved by 1985. A search of the literature, coupled with interviews with representatives of major steel producers, served as the means whereby the techniques and technologies indicated for the specific site are extrapolated to the industry as a whole and to the 1985 time frame. The conclusion of the study is that by 1985, a national yearly savings of 1.9 million barrels of oil could be realized through recovery of waste heat from primary arc furnace fume gases on an industry-wide basis. Economic studies indicate that the proposed system has a plant payback time of approximately 5 years

Towards engineering the perfect defect in high-performing permanent magnets

Permanent magnets draw their properties from a complex interplay, across multiple length scales, of the composition and distribution of their constituting phases, that act as building blocks, each with their associated intrinsic properties. Gaining a fundamental understanding of these interactions is hence key to decipher the origins of their magnetic performance and facilitate the engineering of better-performing magnets, through unlocking the design of the "perfect defects" for ultimate pinning of magnetic domains. Here, we deployed advanced multiscale microscopy and microanalysis on a bulk Sm2(CoFeCuZr)17 pinning-type high-performance magnet with outstanding thermal and chemical stability. Making use of regions with different chemical compositions, we showcase how both a change in the composition and distribution of copper, along with the atomic arrangements enforce the pinning of magnetic domains, as imaged by nanoscale magnetic induction mapping. Micromagnetic simulations bridge the scales to provide an understanding of how these peculiarities of micro- and nanostructure change the hard magnetic behaviour of Sm2(CoFeCuZr)17 magnets. Unveiling the origins of the reduced coercivity allows us to propose an atomic-scale defect and chemistry manipulation strategy to define ways toward future hard magnets

Applications of thermal energy storage to process heat and waste heat recovery in the primary aluminum industry. Final report, September 1977-September 1978

The results of a study entitled, Applications of Thermal Energy Storage to Process Heat and Waste Heat Recovery in the Primary Aluminum Industry are presented. In this preliminary study, a system has been identified by which the large amounts of low-grade waste energy in the primary pollution control system gas stream can be utilized for comfort heating in nearby communities. Energy is stored in the form of hot water, contained in conventional, insulated steel tanks, enabling a more efficient utilization of the constant energy source by the cyclical energy demand. Less expensive energy storage means (heated ponds, aquifers), when they become fully characterized, will allow even more cost-competitive systems. Extensive design tradeoff studies have been performed. These tradeoff studies indicate that a heating demand equivalent to 12,000 single-family residences can be supplied by the energy from the Intalco plant. Using a 30-year payback criterion (consistent with utility planning practice), the average cost of energy supplied over the system useful life is predicted at one-third the average cost of fossil fuel. The study clearly shows that the utilization of waste energy from aluminum plants is both technically and economically attractive. The program included a detailed survey of all aluminum plants within the United States, allowing the site specific analyses to be extrapolated to a national basis. Should waste heat recovery systems be implemented by 1985, a national yearly savings of 6.5 million barrels of oil can be realized

Energy applications of magnetocaloric materials

The need for energy-efficient and environmentally friendly refrigeration, heat pumping, air conditioning, and thermal energy harvesting systems is currently more urgent than ever. Magnetocaloric energy conversion is among the best available alternatives for achieving these technological goals and has been the subject of substantial basic and applied research over the last two decades. The subject is strongly interdisciplinary, requiring proper understanding and efficient integration of knowledge in different specialized fields. This review article presents a historical and up-to-date account of the energy-related applications of magnetocaloric materials and information about their processing and magnetic fields, thermodynamics, heat transfer, and other relevant characteristics. The article also discusses the conceptual design of magnetocaloric refrigeration and power generation systems and some guidelines for future research in the field