Review on research of room temperature magnetic refrigeration

Yu, Bo; Gao, Qingqing; Zhang, B; Meng, Xingwang; Chen, Z

doi:10.1016/s0140-7007(03)00048-3

Cited by 495 publications

(214 citation statements)

References 102 publications

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“…However, many of the magnetocaloric materials that have been proposed for use in magnetic refrigeration devices rely on expensive rare earth elements. [3][4][5] This is also true, to an even greater extent, of the permanent magnet ͑NdFeB͒ magnetic field source, where the price of Nd is the limiting factor. Recently, much work has gone into achieving the greatest cooling power when using a minimum amount of permanent magnet material while still maintaining a large field.…”

Section: Introductionmentioning

confidence: 95%

A versatile magnetic refrigeration test device

Bahl

Petersen

Pryds

et al. 2008

Review of Scientific Instruments

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A magnetic refrigeration test device has been built and tested. The device allows variation and control of many important experimental parameters, such as the type of heat transfer fluid, the movement of the heat transfer fluid, the timing of the refrigeration cycle, and the magnitude of the applied magnetic field. An advanced two-dimensional numerical model has previously been implemented in order to help in the optimization of the design of a refrigeration test device. Qualitative agreement between the results from model and the experimental results is demonstrated for each of the four different parameter variations mentioned above.

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Section: Introductionmentioning

confidence: 95%

A versatile magnetic refrigeration test device

Bahl

Petersen

Pryds

et al. 2008

Review of Scientific Instruments

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“…The ideal Ericsson cycle (two isothermal and two isomagnetic field processes) is optimal for RT applications [2]. Its maximum efficiency is reached when the MCE exhibits a constant temperature dependence of the isothermal magnetic entropy change, ΔS M (T), within the operating temperature range [3].…”

mentioning

confidence: 99%

Enhanced refrigerant capacity and magnetic entropy flattening using a two-amorphous FeZrB(Cu) composite

Álvarez

Llamazares

Gorría

et al. 2011

Applied Physics Letters

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The temperature dependence of the isothermal magnetic entropy change, ΔS M , and the The ideal Ericsson cycle (two isothermal and two isomagnetic field processes) is optimal for RT applications [2]. Its maximum efficiency is reached when the MCE exhibits a constant temperature dependence of the isothermal magnetic entropy change, ΔS M (T), within the operating temperature range [3]. This condition is difficult to be accomplished by a single material, but a composite made of two ferromagnetic materials may fulfill it provided that the difference between their Curie points, T C , is customized [4]. However, sintered mixtures of compounds are not well suited because they behave as a material with a single T C [5]. Instead of that, the design of specific composites [6][7][8] can lead to an enlargement of the MCE temperature span and an almost constant ΔS M (T) curve. The efficiency of the magnetic material in terms of the energy transfer between the cold (T cold ) and hot (T hot ) reservoirs, is quantified by its refrigerant capacity, RC, an important figure of merit that characterizes the magnetocaloric material [9,10]:where T cold and T hot are commonly selected as the temperatures corresponding to the full width at half maximum of ΔS M (T). In order to attain large RC values, a large magnetic entropy change over a wide temperature range is desirable. However, it has been shown that although the maximum value of ΔS M decreases, a large broadening of the ΔS M (T)curves can overcompensate such decrease, giving rise to a significant RC enhancement [7,10]. In turn, numerical calculations and their proof-of-principle in practical systemsshow that the design and practical realization of multiphase or composite magneto-3 caloric materials with optimized RC and ΔS M (T) curves is not a simple task [4][5][6]. For a two-phase composite the magnetic field variation of the RC is complex, and depends on several factors such as ΔT C and the shape, width and peak value of ΔS M (T) curve of the two constituents [6].In this letter we report on the MCE in a two-ribbon composite showing a larger RC with respect to that of each individual ribbon and a flattened ΔS M (T) curve. The composite is formed by two Fe-rich FeZrB(Cu) amorphous ribbons. These alloys, which were extensively studied due to their re-entrant spin-glass fig. 3). This RC enhancement is a consequence of the increase in δT FWHM . Nevertheless, a compromise between the value of the δT FWHM and the potential lost of efficiency of the machine (due to an increase of cycles in the heat exchange medium) is needed. In turns, the ΔS comp (T) curves under low magnetic field changes (μ o ∆H < 0.4 T) exhibit a double-peak profile [see inset of Fig. 2(a)], and the δT FWHM cannot be properly defined. 5Both, the enhancement of RC comp and the flattening observed in the ΔS comp curve stimulated us to measure the M(H) curves for the two-ribbon composite. This is important in order to assess whether the shape of M(H) curves is in some extend affected by dipolar interactions between ...

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“…It utilizes magnetocaloric effect (MCE) which is a reversible change in entropy of magnetic refrigerants according to the variation of external magnetic field [2]. Because of the reversible characteristics, magnetic refrigerator has an intrinsic potential for high efficiency and can be a good candidate to replace or compensate conventional hydrogen liquefier [3]. AMRR which utilizes MCE of material as a regenerator has been focused on hydrogen liquefaction.…”

Section: Introductionmentioning

confidence: 99%

Investigation on the two-stage active magnetic regenerative refrigerator for liquefaction of hydrogen

Park¹,

Kim²,

Park³

et al. 2014

AIP Conference Proceedings

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Abstract. An active magnetic regenerative refrigerator (AMRR) is expected to be useful for hydrogen liquefaction due to its inherent high thermodynamic efficiency. Because the temperature of the cold end of the refrigerator has to be approximately liquid temperature, a large temperature span of the active magnetic regenerator (AMR) is indispensable when the heat sink temperature is liquid nitrogen temperature or higher. Since magnetic refrigerants are only effective in the vicinity of their own transition temperatures, which limit the temperature span of the AMR, an innovative structure is needed to increase the temperature span. The AMR must be a layered structure and the thermophysical matching of magnetic field and flow convection effects is very important. In order to design an AMR for liquefaction of hydrogen, the implementation of multilayered AMR with different magnetic refrigerants is explored with multi-staging. In this paper, the performance of the multi-layered AMR using four rare-earth compounds (GdNi 2 , Gd 0.1 Dy 0.9 Ni 2 , Dy0 .85 Er 0.15 Al 2 , Dy 0.5 Er 0.5 Al 2 ) is investigated. The experimental apparatus includes two-stage active magnetic regenerator containing two different magnetic refrigerants each. A liquid nitrogen reservoir connected to the warm end of the AMR maintains the temperature of the warm end around 77 K. High-pressure helium gas is employed as a heat transfer fluid in the AMR and the maximum magnetic field of 4 T is supplied by the low temperature superconducting (LTS) magnet. The temperature span with the variation of parameters such as phase difference between magnetic field and mass flow rate of magnetic refrigerants in AMR is investigated. The maximum temperature span in the experiment is recorded as 50 K and several performance issues have been discussed in this paper.

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Review on research of room temperature magnetic refrigeration

Cited by 495 publications

References 102 publications

A versatile magnetic refrigeration test device

A versatile magnetic refrigeration test device

Enhanced refrigerant capacity and magnetic entropy flattening using a two-amorphous FeZrB(Cu) composite

Investigation on the two-stage active magnetic regenerative refrigerator for liquefaction of hydrogen

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