共查询到18条相似文献,搜索用时 109 毫秒
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室温磁制冷研究新动态及应用 总被引:3,自引:0,他引:3
室温磁制冷是磁制冷技术发展的必然趋势.本文介绍了近10年室温磁制冷研究的最新动态,分析了磁制冷循环理论研究的结果,详细说明了室温磁制冷材料和样机的新近成果,并对室温磁制冷的商业化应用前景进行了展望. 相似文献
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应用有限时间热力学理论研究了顺磁质Ericsson制冷循环的优化,得出了最佳制冷率和制冷系数之间的基本优化关系,取得了一些有意义的结果。对这类实际制冷机优化设计具有指导意义。 相似文献
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回热损失对磁斯特林制冷循环制冷率的影响 总被引:7,自引:0,他引:7
从铁磁质的磁化强度一般表示式出发,探讨热阻和回热损失对磁斯特林制冷循环性能的影响,导出最大制冷率及其它性能参数。得到了结果适用于以顺磁质为工质的磁斯特林制冷循环。并指出在理想回热条件下的结论也适用于磁卡诺制冷循环。 相似文献
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磁制冷技术作为一种环保高效的新型制冷技术,受到了越来越多人的关注。与传统的气体压缩式制冷相比,磁制冷具有非常大的竞争力。随着材料科学和制冷循环理论等的不断发展,磁制冷技术必然有着广阔的发展前景。阐述了磁制冷技术的工作原理和典型磁制冷循环的研究进展情况,重点介绍了磁性材料以及活性蓄冷器的最新研究现状。 相似文献
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刘涛 《制冷与空调(四川)》2009,23(1)
磁制冷技术是一种极具发展潜力的制冷技术,其具有节能、环保的特点.介绍了磁制冷的工作原理、磁性材料的选择与研究进展情况,磁制冷循环及磁制冷机的研究进展,并指出磁制冷技术发展需要解决的问题. 相似文献
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H.R.E.H. Bouchekara A. Kedous-LeboucJ.P. Yonnet 《International Journal of Refrigeration》2012,35(1):115-121
Magnetic refrigeration (MR) based on the magnetocaloric effect (MCE) is a prime candidate for the next generation of cooling systems. The essential components of magnetic refrigeration are the magnetic field generator and the magnetocaloric material. Although, several permanent magnet systems (magnetic field sources) for MR have been developed, recent development in magnetic refrigeration technology has encouraged researchers all over the world to think about new and original systems. This paper aims to describe a new and original magnetic refrigeration system based on a simple principle of magnetism called the Halbach effect. The proposed system is running with rotating bar-shaped magnets. This structure provides the desired varying magnetic field to the magnetocaloric material. Several configurations for the proposed systems have been investigated and presented in this paper. The design and modeling have been accomplished by using the finite elements method. 相似文献
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磁制冷技术商品化开发的可行性探索 总被引:2,自引:0,他引:2
本文利用最新的国外资料 ,对新型的磁制冷技术商品化开发中存在的一些问题进行了探讨 ,指出磁制冷材料和热交换技术是磁制冷技术商品化开发的主要难关并提出了解决这两个难关的探索性方案。 相似文献
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Based on the thermodynamic properties of a paramagnetic salt, an irreversible model of the magnetic Brayton refrigeration cycle is established, in which the working substance is a special paramagnetic material. The expressions of the important performance parameters, such as the coefficient of performance, refrigeration load and work input, are derived. Moreover, the optimal performance parameters are obtained at the maximum coefficient of performance. The results obtained here may include the ones of the magnetic Brayton refrigeration cycle using the magnetic material obeyed the Curie law as the working substance, the magnetic Brayton refrigeration cycle without regeneration and the eversible magnetic Brayton refrigeration cycle. Therefore, the results obtained here have general significance and will be helpful to deeply understand the performance of a magnetic Brayton refrigeration cycle. 相似文献
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Current models of Active Magnetic Regenerative Refrigeration (AMRR) cycles are not able to capture the effect of magnetic hysteresis and are therefore strictly limited to second order magnetic transition (SOMT) materials. The discovery of the giant magnetocaloric effect (GMCE) in first order magnetic transition (FOMT) materials has generated substantial interest. FOMTs yield large adiabatic temperature changes but also exhibit significant magnetic hysteresis. This work quantifies the effects of magnetic hysteresis. Thermodynamically, hysteresis is treated as a source of entropy generation that is proportional to the area swept by the hysteresis loop experienced locally by the material during one refrigeration cycle. The 1-D numerical model presented by Engelbrecht (2008) is modified to include magnetic hysteresis. Hysteresis losses are shown to be directly proportional to regenerator volume. Therefore, at large refrigeration capacity to volume ratios, AMRR beds using layered FOMT materials significantly outperform the same cycle using layered SOMT refrigerants. 相似文献
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《低温学》2014
This paper reviews the status of magnetic refrigeration system for hydrogen liquefaction. There is no doubt that hydrogen is one of most important energy sources in the near future. In particular, liquid hydrogen can be utilized for infrastructure construction consisting of storage and transportation. When we compare the consuming energy of hydrogen liquefaction with high pressurized hydrogen gas, FOM must be larger than 0.57 for hydrogen liquefaction. Thus, we need to develop a highly efficient liquefaction method. Magnetic refrigeration using the magneto-caloric effect has potential to realize not only the higher liquefaction efficiency >50%, but also to be environmentally friendly and cost effective. Our hydrogen magnetic refrigeration system consists of Carnot cycle for liquefaction stage and AMR (active magnetic regenerator) cycle for precooling stages. For the Carnot cycle, we develop the high efficient system with >80% liquefaction efficiency by using the heat pipe. For the AMR cycle, we studied two kinds of displacer systems, which transferred the working fluid. We confirmed the AMR effect with the cooling temperature span of 12 K for 1.8 T of the magnetic field and 6 s of the cycle. By using the simulation, we estimate the efficiency of the hydrogen liquefaction plant for 10 kg/day. A FOM of 0.47 is obtained for operation temperature between 20 K and 77 K including LN2 work input. 相似文献
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K.K. Nielsen J. TusekK. Engelbrecht S. SchopferA. Kitanovski C.R.H. BahlA. Smith N. PrydsA. Poredos 《International Journal of Refrigeration》2011,34(3):603-616
The active magnetic regenerator (AMR) is an alternative refrigeration cycle with a potential gain of energy efficiency compared to conventional refrigeration techniques. The AMR poses a complex problem of heat transfer, fluid dynamics and magnetic field, which requires detailed and robust modeling. This paper reviews the existing numerical modeling of room temperature AMR to date. The governing equations, implementation of the magnetocaloric effect (MCE), fluid flow and magnetic field profiles, thermal conduction etc. are discussed in detail as is their impact on the AMR cycle. Flow channeling effects, hysteresis, thermal losses and demagnetizing fields are discussed and it is concluded that more detailed modeling of these phenomena is required to obtain a better understanding of the AMR cycle. 相似文献