WO1999020956A1 - Cold-accumulating material and cold-accumulating refrigerator - Google Patents
Cold-accumulating material and cold-accumulating refrigerator Download PDFInfo
- Publication number
- WO1999020956A1 WO1999020956A1 PCT/JP1998/004749 JP9804749W WO9920956A1 WO 1999020956 A1 WO1999020956 A1 WO 1999020956A1 JP 9804749 W JP9804749 W JP 9804749W WO 9920956 A1 WO9920956 A1 WO 9920956A1
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- WIPO (PCT)
- Prior art keywords
- regenerator
- magnetic
- refrigerator
- cold storage
- specific heat
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Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/012—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials adapted for magnetic entropy change by magnetocaloric effect, e.g. used as magnetic refrigerating material
- H01F1/015—Metals or alloys
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B9/00—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point
- F25B9/14—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the cycle used, e.g. Stirling cycle
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/0009—Antiferromagnetic materials, i.e. materials exhibiting a Néel transition temperature
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2309/00—Gas cycle refrigeration machines
- F25B2309/003—Gas cycle refrigeration machines characterised by construction or composition of the regenerator
Definitions
- the present invention relates to a regenerator material and a regenerative refrigerator, and more particularly to a regenerator material capable of exhibiting a remarkable refrigerating capacity in an extremely low temperature region of 10 K or less, a regenerative refrigerator using the regenerator material, and the like.
- refrigerators using a refrigeration cycle such as the Gifford's McMahon (GM) system or the Stirling system are used. Also, high-performance refrigeration equipment is required for maglev trains. In recent years, high-performance refrigerators have also been used in superconducting power storage devices (SMES) and magnetic crystal single crystal bow I lifters that produce high-quality silicon wafers.
- SMES superconducting power storage devices
- a working medium such as a compressed He gas flows in one direction in the regenerator filled with the regenerator material, supplies the heat energy to the regenerator material, and expands there.
- the working medium flows in the opposite direction, Receive heat energy.
- Magnetic regenerator material mainly composed of an intermetallic compound composed of a rare earth element and a transition metal element, such as Er 3 Ni, Er Ni, Ho Cu 2, etc. It is used.
- a magnetic regenerator material for a GM refrigerator, refrigeration at 4 K has been realized.
- application of such a refrigerator to various systems will be studied more specifically. As a result, technical requirements for cooling large-scale cooling objects in a stable state for a long period of time have increased, and further improvement in refrigeration capacity has been demanded.
- the working medium flows into the regenerator of the last cooling stage of a regenerative refrigerator having a plurality of cooling stages, that is, in the case of a two-stage expansion refrigerator, inside the second regenerator.
- the temperature gradient is formed such that the temperature at the high-temperature end is about 30 K, while the temperature at the downstream low-temperature end is about 4 K. Is done.
- each regenerator material having a specific heat characteristic suitable for each temperature region is actually filled according to the temperature distribution inside the regenerator.
- the low-temperature side of the regenerator for example, H 0 C while the volume specific heat as much as possible wide temperature region on the low temperature side as u 9 fills the large cold storage material, the high temperature side, for example E r 3 N i
- a regenerator material with a large volume specific heat over a wide temperature range on the high temperature side is stacked and filled.
- the main factor that has a significant effect on refrigerator performance in the extremely low temperature range of about 4 K is the type of cold storage material that is charged on the low temperature side of the regenerator.
- the regenerator materials to be charged on the low-temperature side of the regenerator include Er Ni 2 , Er Ni Q 0 Co Q ⁇ , Er Ni Q 8 Co Q , Er Rh and Ho Cu Cold storage materials having various compositions, such as 2 , have been studied and used.
- these regenerator materials are used for the second-stage regenerator of a normal two-stage expansion GM refrigerator, the refrigerating capacity at 4 K is particularly high in HoCu 2 , but the volume in the 4K region is still high. Due to insufficient specific heat, no significant improvement in refrigeration capacity has been achieved.
- the E r N i 2, the ErN i fi 9 Co Q 1, E rN i ⁇ o Cc ⁇ cold accumulating material made of a ferromagnetic material such as, when applied to a superconducting system refrigerator, leakage from the superconducting magnet
- a magnetic force acts on a component of a refrigerator to cause uneven wear or deformation.
- the cold storage material made of ErRh is an antiferromagnetic material, and has the advantage of being less susceptible to the above-mentioned stray magnetic field.
- rhodium (Rh) power as a component is extremely expensive, and is used in the order of several hundred grams.
- the present invention has been made in order to solve the above problems, and particularly, a cold storage material capable of stably exhibiting a remarkable refrigeration capacity in an extremely low temperature range over a long period of time, and a cold storage material using the same. It is intended to provide a refrigerator or the like.
- the use of the regenerative refrigerator as described above enables the super-conducting magnets for MR I disturbed magnetic levitation trains, cryopumps, and magnetic field-applied single units to be able to exhibit excellent performance for a long time. It aims at providing a crystal bow I raising device.
- regenerator materials having various compositions and specific heat characteristics and fill them into a regenerator of a refrigerator.
- the effects on the life and durability of the materials were compared by experiments.
- the regenerator material with a large volume specific heat power in a limited temperature range, especially around 4 K was designed to fill the regenerator according to the specific heat characteristics of the high-temperature side. It was found that the refrigerating capacity of the machine was significantly improved. For example, when using a regenerator material that has a high specific heat at 4 K and a low specific heat at 10 K, consider the temperature distribution inside the regenerator and apply it only on the low-temperature side of the regenerator. It was found that by filling, the high specific heat characteristics at 4 K of the regenerator material were utilized, and the performance of the refrigerator was greatly improved.
- the present inventors have Focusing on H o C u 2 magnetic material having a high body volume specific heat at cryogenic temperatures of 4 K in the magnetic cold accumulating material has been put to practical use in in, by substituting a part of Eta 0 in other rare earth elements It has been found that the intended specific heat characteristics can be realized for the first time by replacing the part of Cu with an element such as a transition metal.
- the present invention has been completed based on the above findings.
- the cold storage material according to the present invention is:
- M is Ag, Au, A1, Ga, In, Ge, Sn, Sb, Si, Bi, Ni, Pd, Pt, Zn, Co, Rh, I at least one element selected from r, Mn, Fe, Ru, Cr, Mo, W, V, Nb, Ta, Ti, Zr, and Hf; Are not selected at the same time, and X satisfies the atomic ratio of -0.95 ⁇ x ⁇ 0.90.)).
- R is at least one rare earth element selected from Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Er, Tm and Yb
- M is Ag, Au, A1, Ga, In, Ge, Sn, Sb, Si, Bi, Ni, Pd, Pt, Zn, Co, Rh, Ir, Mn, At least one element selected from Fe, Ru, Cr, Mo, W, V, Nb, Ta, Ti, Zr, and Hf, where x and y are O x O. 5, 0 ⁇ y ⁇ 0.5 and x + y ⁇ 0.) It is characterized by being composed of a magnetic material represented by.
- the magnetic substance represented by the general formula (1) or (2) It has a hexagonal or orthorhombic crystal structure at a vol.% or more ratio.
- the magnetic material is preferably an antiferromagnetic material.
- the regenerative refrigerator according to the present invention has a plurality of cooling stages each composed of a regenerator filled with a regenerator material, and the operating medium flows from the high-temperature side upstream of the regenerator in each of the cooling stages so that the operating medium and the regenerator are cooled.
- a regenerative refrigerator in which a lower temperature is obtained downstream of the regenerator by heat exchange with the material, at least a part of the regenerator material filled in the regenerator has the general formula It is characterized by comprising a cold storage material represented by (1) or general formula (2). It is preferable that the regenerator material be filled into the low-temperature side (final cooling stage) downstream of the regenerator.
- an MR I (Magnetic Resonance Imaging) device each include the regenerative refrigerator according to the present invention described above. It is characterized by
- the regenerator material according to the present invention is composed of a magnetic material in which the amount of the Cu component and the amount of the M component with respect to the R component are appropriately adjusted, or has a basic composition of HoCu. It consists of a magnetic material in which a part of the Ho component of the magnetic material is replaced with an R component, or a part of the Cu component is replaced with an M component.
- the R component is represented by Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Er, Ho ( Is at least one element selected from the general formula (2)), Tm and Yb, and the M component is Ag, Au, A1, Ga, In, Ge, Sn, Sb, Si, B i, Ni, Pd, Pt, Zn, Co, Rh, Ir, Mn, Fe, Ru, Cr, Mo, W, V, Nb, Ta, Ti, Zr and at least one selected from Hf One kind of element.
- These R and M components are t and the deviation is the temperature of the volume specific heat peak of the magnetic material. It is added to move the device to a lower temperature side or to widen the half width of the peak to realize effective specific heat characteristics as a cold storage material.
- the addition and subtraction X of the Cu component and the M component with respect to the R component is in the range of ⁇ 0.95 to 0.90 in atomic ratio.
- the weight loss X is less than — 0.95, RC u ⁇ ⁇ M 1+ approaches the substantially simple binary system RCu 2 , or when X exceeds 0.90, it becomes substantially
- the RM Q approaches, and the half width of the specific heat peak of the magnetic material becomes narrow, so that it becomes impossible to maintain a high specific heat in a wide temperature range, and it is difficult to control the temperature position of the specific heat peak.
- X is particularly preferably 0.60 ⁇ x ⁇ .60 force.
- the range of 0.40 ⁇ x0.40 is preferable.
- the substitution amounts X and y of the R component and the M component with respect to Ho and Cu are each in the range of 0 to 0.5 in atomic ratio. If the above substitution amount X or y exceeds 0.5, the temperature position of the volume specific heat peak moves significantly, and the volume specific heat in the target temperature region around 4 K decreases, or half of the specific heat peak. The range of the value becomes too wide, the peak height decreases, the volume specific heat of the magnetic material in an extremely low temperature range becomes insufficient, and the function as a cold storage material decreases.
- the R component and the M in order to shift the temperature position of the volume specific heat peak to a lower temperature side or to effectively increase the half width of the specific heat peak, the R component and the M This is achieved by adding at least one of the components. Therefore, although the lower limits of the addition amounts (substitution amounts) X and y of the R component and the M component are both defined to include zero, the X value and the y value do not become zero at the same time. That is, the relational expression of x + y ⁇ 0 is satisfied.
- the R component is At least one of the above rare earth elements can be used. Among them, Ce, Pr, Nd, Er, Dy, Ho (except in general formula (2): :), Tb and Gd are cold storage Pr, Nd, Er, Dy, and Ho (except in the general formula (2)) are preferred for improving the specific heat characteristics of the material.
- the M component among the metal elements, Ag, A1, i, Ga, In, Ge, Sn, and Si are particularly preferable. Further, Al, Ga, Ge, and Sn are preferable.
- the R component by selecting a plurality of elements, the half width of the specific heat peak of the magnetic material and the temperature position of the specific heat peak can be controlled.
- a magnetic material having at least 50 vol.% (50 to 99.99 vol.%) Having a hexagonal or orthorhombic crystal structure is particularly preferable.
- Hexagonal or orthorhombic is a crystal structure with less symmetry than cubic. It has been confirmed by the present inventors that the symmetry of the crystal structure affects the specific heat characteristics of the cold storage material through the effect of the crystal field.
- a crystal structure with high symmetry such as a cubic crystal, which generally has a narrow half-value width and a steep specific heat peak, has been considered to be preferable as a regenerator material.
- the inventor of the present application has focused on a broad specific heat peak having a wide half-value width, rather than a steep peak.
- a magnetic material mainly composed of hexagonal crystal or orthorhombic crystal with low symmetry can realize higher specific heat in a wider temperature range.
- Hexagonal crystal has slightly higher crystal symmetry than orthorhombic, and exhibits intermediate crystal symmetry between cubic and orthorhombic, so the peak value of specific heat is relatively high and the half-width is relatively wide . That is, it is particularly preferable because a well-balanced specific heat characteristic can be obtained in a wide temperature range.
- the substance represented by the general formula (1) or (2) is a rare earth element.
- the composition of the composition (metal structure) is slightly different (mixing), the composition is slightly different, the amount of trace impurities such as oxygen and carbon, the dissolution temperature, the dissolution atmosphere, and the like.
- the cooling process in the high temperature region from the melting point to the solidus line affects the metallographic structure sensitively and is extremely difficult to control.
- the metal structure of the magnetic material constituting the cold storage material of the present invention contains a rare earth metal or a solid solution thereof. That is, since the rare earth metal or its solid solution has a lower specific heat characteristic than the intermetallic compound containing the rare earth element, it is preferable that the rare earth metal or the solid solution is not precipitated in the structure as much as possible.
- the metal structure in which the rare earth metal or its solid solution is not precipitated can be realized by slightly reducing the R component in the raw material preparation stage from the target composition.
- the ratio of the magnetic substance having a hexagonal or orthorhombic crystal structure is preferably 50 vo 1.% or more.
- the specific heat becomes insufficient and the specific heat peak becomes sharp, so that the cold storage effect is reduced when used as a cold storage material.
- the proportion of the magnetic material having an orthorhombic or orthorhombic crystal structure is more preferably 70 vol.% Or more, and further preferably 80 vol.% Or more.
- the morphology of the metal structure that composes the magnetic material may include slight differences in the composition (preparation), content of trace impurities such as oxygen and carbon, melting temperature, melting atmosphere, and solidification rate. Almost affected by Therefore, it is difficult to uniquely specify a method for realizing the above-described metallographic structure for the magnetic material represented by the general formula (1) or (2). is there. In particular, the phase diagram becomes complicated for ternary materials or more, and it is even more difficult to specify a method for realizing a desired metallographic structure.
- magnetic particles are prepared from a raw material molten metal by a rapid solidification method such as a centrifugal spray method or a gas atomizing method, and the temperature of the molten metal in that case is adjusted. It has been confirmed that by setting the melting point of the raw material 100 to 300 K higher than that of the raw material, the above metal structure can be easily obtained at a desired ratio.
- the above-mentioned regenerative material may be composed of spherical magnetic particles having a uniform particle diameter. More specifically, the ratio of the major axis to the minor axis (aspect ratio) is 5 or less, and the particle diameter is between 0.01 and 3 and less than or equal to the total magnetic particles constituting the cold storage material. It is preferable to adjust the ratio of the magnetic particles having the following to be not less than 0% by weight.
- the particle size of the magnetic particles is a factor that has a great effect on the particle strength, the cooling function of the refrigerator, and the heat transfer characteristics. If the particle size is less than 0.01, it is difficult to fill the regenerator. Is too high, the passage resistance (pressure loss) of the He gas as the cooling medium increases rapidly, and in addition to the flowing He gas, it enters the compressor and quickly moves the components. Will wear out.
- the average particle size is set to be 0.0 lmm or more and 3 thighs or less, more preferably in the range of 0.05 to 1.0 thighs, and more preferably 0.05 to 1.0. It is preferably from l mm to 0.5 mm.
- the particles having the above particle diameter should be at least 70% by weight, preferably at least 80% by weight, more preferably at least 70% by weight based on the whole magnetic regenerator material particles. Preferably, it occupies 90% or more.
- the ratio of the major axis to the minor axis of the magnetic particles is set to 5 or less, preferably 3 or less, more preferably 2 or less, and even more preferably 1.3 or less.
- the aspect ratio of magnetic particles has a large effect on the strength of the particles and the packing density and uniformity when filling the regenerator, and when the aspect ratio exceeds 5, mechanical properties As a result, the magnetic particles are liable to deform and break, and it is difficult to uniformly and densely fill the regenerator so that the void force ⁇ homogenous. Exceeding the weight percentage may cause a decrease in the efficiency of cold storage.
- the variation in the particle size of the magnetic particles prepared by the melt quenching method and the variation in the ratio of the major axis to the minor axis are greatly reduced as compared with the case of the conventional plasma spray method.
- the ratio of outside magnetic particles is small.
- the ratio of magnetic particles having an aspect ratio within the above range is 70% or more, preferably 80% or more, and more preferably 90% or more.
- the average crystal grain size of the magnetic particles prepared by the molten metal quenching method is set to 0.5 mm or less, or by making at least a part of the metal structure amorphous, extremely high strength and long life are obtained. L, magnetic particles can be formed.
- the surface roughness of magnetic particles is a factor that has a large effect on mechanical strength, cooling characteristics, resistance to passage of cooling medium, cold storage efficiency, etc.
- the surface roughness can be measured by a scanning tunnel microscope (STM roughness meter).
- the proportion of magnetic particles having minute defects with a length of 10 / zm or more that affects the mechanical strength of the magnetic particles is 30% or less, preferably 10% or less, more preferably 10% or less of the whole. % Is practically desirable.
- the method for producing the magnetic regenerator particles as described above is not particularly limited, and various general-purpose alloy particle production methods can be applied.
- a method of dispersing a molten metal having a predetermined composition according to a centrifugal spraying method, a gas atomizing method, a rotating electrode method, and the like, and at the same time rapidly solidifying the molten metal (a molten metal quenching method) can be applied.
- the metal structure inside the magnetic regenerator material particles can be adjusted by the general formula (1) or by adjusting the composition of the melt slightly to Cu rich or appropriately controlling the solidification rate. It is possible to have a multiphase metallic structure composed of an antiferromagnetic material represented by (2) and Cu metal.
- Magnetic regenerator particles having a metal structure with such a Cu metal phase formed Because of its high mechanical strength, it can be destroyed even if impact force due to vibrations during operation of the refrigerator acts on the cold storage material, or if excessive stress force ⁇ acts when filling the cold storage unit. There is no pulverization.
- micronization such as fine powder of regenerator material being entrained by the working medium and penetrating into the seal of the refrigerator, causing damage, and extending the performance of the refrigerator.
- a regenerative refrigerator according to the present invention is configured by filling at least a part of the regenerator in a final cooling stage of a refrigerator having a plurality of cooling stages with the magnetic regenerator particles.
- the present invention relates to the low-temperature end of the second-stage regenerator, and in a three-stage expansion refrigerator, the low-temperature end of the third-stage regenerator according to the present invention. While the magnetic regenerator material particles are filled, the other regenerator material filling space is filled with another regenerator material having specific heat characteristics according to the temperature distribution.
- the filling weight of the magnetic regenerator particles of the present invention in the regenerator of the above-mentioned final cooling stage is less than 1% by weight / weight ratio, the improvement of the regenerative efficiency of the refrigerator is not recognized.
- the filling amount is too large to exceed 80% by weight, the drawbacks of the magnetic regenerator material particles of the present invention become remarkable, and similarly, the regenerative efficiency decreases.
- a relatively small volume specific heat in a temperature range other than the temperature at which the volume specific heat peaks, particularly in a high temperature range adversely affects the entire regenerator, resulting in a decrease in the cool storage efficiency.
- the filling amount of the magnetic regenerator particles of the present invention with respect to the total weight of the particles charged in the regenerator in the final cooling stage is in the range of 1 to 80% by weight, preferably 2 to 70% by weight. And more preferably in the range of 3 to 50% by weight.
- the Cu and M components with respect to the R component are appropriately adjusted, or the peak of the volume specific heat is sharp in an extremely low temperature region. Since some of the constituents of the H 0 Cu 2 magnetic material having the following characteristics are substituted with other rare earth elements or transition metals, the temperature position of the volume specific heat peak shifts to a lower temperature and the specific heat peak becomes half of the specific heat peak.
- the price range is expanded, and a cool storage material with excellent specific heat characteristics can be obtained.
- the refrigerating capacity in the temperature range of 4 K is high and stable refrigerating performance is maintained over a long period of time. It is possible to provide a refrigerator that can be used.
- the performance of the refrigerator depends on the performance of each device.
- the MRI apparatus, the cryopump, the superconducting magnet for a magnetically levitated train, and the magnetic field application type single crystal pulling apparatus of the present invention using a refrigerator can exhibit excellent performance over a long period of time.
- FIG. 1 is a cross-sectional view showing a configuration of a main part of a regenerative refrigerator (GM refrigerator) according to the present invention.
- FIG. 2 is a graph comparing the specific heat characteristics of the cold storage materials according to the example and the comparative example.
- FIG. 3 is a sectional view showing a schematic configuration of a superconducting MRI apparatus according to one embodiment of the present invention.
- FIG. 4 is a perspective view showing a schematic configuration of a main part of a superconducting magnet (for a magnetic levitation train) according to an embodiment of the present invention.
- FIG. 5 is a sectional view showing a schematic configuration of a cryopump according to one embodiment of the present invention.
- FIG. 6 is a perspective view showing a schematic configuration of a main part of a magnetic field applying type single crystal bow I raising device according to an embodiment of the present invention.
- a two-stage expansion GM refrigerator as shown in Fig. 1 was prepared. It is shown in Fig. 1.
- the two-stage GM refrigerator 10 shows one embodiment of the refrigerator of the present invention.
- the two-stage GM refrigerator 10 shown in FIG. 1 has a large-diameter first cylinder 11 and a small-diameter second cylinder 12 coaxially connected to the first cylinder 11. Vacuum container 13.
- a first regenerator 14 is arranged reciprocally in the first cylinder 11, and a second regenerator 15 is arranged reciprocally in the second cylinder 12.
- Seal rings 16 and 17 are arranged between the first cylinder 11 and the first regenerator 14 and between the second cylinder 12 and the second regenerator 15, respectively.
- the first regenerator 14 contains a first regenerator material 18 such as a Cu mesh. On the low-tone side of the second regenerator 15, the extremely low-temperature regenerative material of the present invention is accommodated as the second regenerative material 19.
- Each of the first regenerator 14 and the second regenerator 15 has a passage of a working medium such as He gas provided in a gap or the like between the first regenerator 18 and the cryogenic regenerator 19. ing.
- a first expansion chamber 20 is provided between the first regenerator 14 and the second regenerator 15.
- a second expansion chamber 21 is provided between the second regenerator 15 and the end wall of the second cylinder 12. Then, a first cooling stage 22 is formed at the bottom of the first expansion chamber 20, and a second cooling stage 23 lower than the first cooling stage 22 is formed at the bottom of the second expansion chamber 21. ing.
- a high-pressure working medium (for example, He gas) is supplied from the compressor 24 to the two-stage GM refrigerator 10 as described above.
- the supplied working medium passes through the first cold storage material 18 accommodated in the first regenerator 14, reaches the first expansion chamber 20, and further reaches the poles accommodated in the second regenerator 15. It passes through the low-temperature cold storage material (second cold storage material) 19 and reaches the second expansion chamber 21.
- the working medium is cooled by supplying heat energy to each of the cold storage materials 18 and 19.
- the working medium that has passed between the cold storage materials 18 and 19 expands in the expansion chambers 20 and 21 to generate cold, and the cooling stages 22 and 23 are cooled. expansion
- the working medium flows between the cold storage materials 18 and 19 in the opposite direction.
- the working medium is discharged after receiving heat energy from each of the cold storage materials 18 and 19.
- the recuperation effect becomes better in such a process, the thermal efficiency of the working medium cycle is improved, and a lower L and temperature are realized.
- 200 g of the cold storage material according to each of the cold examples 1 to 23 prepared as described above was charged into the low-temperature side of the second-stage regenerator of the above-described two-stage expansion GM refrigerator. Further, at the high temperature side the E r 3 N i regenerator material 1 5 0 g each filled assembled refrigerator according to actual ⁇ 1-2 3 conducted frozen test, 3 0 0 0 hours after continuous operation The refrigeration capacity was measured.
- the refrigerating capacity in this example was defined as a heat load when a heat load was applied to the second cooling stage by the heater during the operation of the refrigerator and the temperature rise in the second cooling stage stopped at 4.2 K.
- Comparative Example 1, 2 as a conventional composition (E r 3 N i, E r N i 2) were respectively prepared master alloy of.
- Comparative Example 3 without adding R component and M component, H o, blended C u metallic material, to prepare a mother alloy having a H o C u 2 0 having a composition by high frequency melting method. These were melted at about 3 5 0 K above the melting point of each mother alloy as a composition, each molten alloy obtained, pressure is 9 OKP a of A in a r atmosphere 1 X 1 0 4 rpm
- Each magnetic particle was produced by dropping onto a rotating disk at a speed of and rapidly solidifying.
- Table 1 shows the results of identifying the crystal structure of each regenerator according to each comparative example by X-ray diffraction and calculating the abundance ratio of the crystal structure from the X-ray diffraction peak.
- 4 2 vol.% Of the E r N i 2 made cold accumulating material of Comparative Example 2 from the orthorhombic formation It was confirmed that the remaining 58 vol.% Consisted of cubic crystals.
- a mother alloy having the same composition (HoCuA 1) as in Example 1 was produced by the high frequency melting method.
- the obtained mother alloy was pulverized with a non-abrasive mill to prepare a pulverized powder having a particle size of 0.2-0.3 mm.
- the obtained pulverized powder was processed into a spherical shape by dissolving and dispersing it in a Ar atmosphere by a plasma spray method.
- the final Ar gas pressure reached in this plasma spray treatment was 180 KPa.
- the crystal structure and the abundance ratio of the spherical particles were measured in the same manner as in the example, and the results shown in Table 1 were obtained.
- Atomic percent (at.%) Composition ratio of In is ⁇ 10 42 Ji 11 29 eight 1 29 Dearu spherical particles were prepared under the same conditions as in Example 1.
- the crystal structure of the obtained spherical particles was identified by X-ray diffraction, and the results shown in Table 1 were obtained. Further, when the obtained particles were observed by the EPMA method, the presence of an H 0 layer on the surface of the particles was confirmed.
- the obtained regenerator material of each comparative example was charged into the low-temperature side of the second stage regenerator of the two-stage expansion type GM refrigerator shown in FIG. Further, the refrigerator of each comparative example was assembled by filling 150 g of Er Ni regenerator material on the high-temperature side, and a refrigerating test was performed, and the refrigerating capacity after 3000 hours of continuous operation was measured.
- Table 1 summarizes the results of measuring the refrigerating capacity of each refrigerator.
- the deterioration of the refrigerating capacity was small even after long-term continuous operation because the mechanical strength of the regenerator material increased and the refrigerating machine was stable. It turned out that I could maintain my ability.
- FIG. 2 shows H o C i ⁇ . Is a graph comparing the specific heat characteristics of the cold accumulating material of Comparative Example 3 having a ⁇ cold material and H o C u 2 0 a composition according to Example 2 with A l ⁇ 8 a composition.
- the regenerator material according to the second embodiment has a higher specific heat in the low-temperature region than the regenerator material according to Comparative Example 3, so that when the regenerator material is filled in the regenerator of the refrigerator, the refrigerating capacity increases. However, it is found that the start-up property of the refrigeration operation is also improved.
- the cold storage material of Comparative Example 4 was prepared by the conventional plasma spray method, the structure of the cold storage material of the present invention was substantially different from that of the cold storage material of the present application using the rapid solidification method, and it was hexagonal. Sufficient refrigerating capacity has not been achieved because the crystal structure ratio is small.
- the cold storage material of Comparative Example 5 since the amount of the rare earth component (R) was relatively increased and a large number of subphases containing the rare earth metal and its solid solution were formed, the cold storage effect was not sufficiently exhibited. No.
- the amount of the rare-earth component was relatively reduced, the rare-earth metal was not precipitated, and all of the materials except impurities were intermetallic compounds. High refrigeration capacity has been demonstrated.
- FIG. 3 is a sectional view showing a schematic configuration of a superconducting MRI apparatus to which the present invention is applied.
- the superconducting MRI device 30 shown in Fig. 3 is a superconducting static magnetic field coil 31 that applies a spatially uniform and temporally stable static magnetic field to the human body, and detects nonuniformity of the generated magnetic field. It is composed of a correction coil (not shown), a gradient magnetic field coil 32 for giving a magnetic field gradient to the measurement area, and a radio wave transmitting / receiving probe 33.
- the regenerative refrigerator 34 according to the present invention as described above is used for cooling the superconducting static magnetic field coil 31.
- 35 is a cryostat and 36 is a radiation insulation shield.
- the superconducting MR device 30 using the regenerative refrigerator 34 since the operating temperature of the superconducting static magnetic field coil 31 can be stably ensured over a long period of time, spatially A uniform and stable magnetic field can be obtained over a long period of time. Therefore, the performance of the superconducting MRI device 30 can be stably exhibited over a long period of time.
- FIG. 4 is a perspective view showing a schematic configuration of a main part of a superconducting magnet for a magnetic levitation train using a regenerative refrigerator according to the present invention, showing a part of a superconducting magnet 40 for a magnetic levitation train.
- the superconducting magnet 40 for the magnetic levitation train shown in FIG. It is constituted by a regenerative refrigerator 44 and the like according to the invention.
- 45 is a laminated heat insulating material
- 46 is a power lead
- 47 is a permanent current switch.
- the operating temperature of the superconducting coil 41 is reduced over a long period of time.
- the magnetic field necessary for magnetic levitation and propulsion of the train can be obtained stably over a long period of time.
- the force acting on the accelerating force The regenerative refrigerator 44 according to the present invention can maintain excellent refrigerating capacity for a long period of time even when acting on the accelerating force. It greatly contributes to long-term stability of strength. Therefore, a magnetic levitation train using such a superconducting magnet 40 can exhibit its reliability over a long period of time.
- FIG. 5 is a sectional view showing a schematic configuration of a cryopump using the regenerative refrigerator according to the present invention.
- a cryopump 50 shown in FIG. 5 includes a cryopanel 51 that condenses or adsorbs gas molecules, a regenerative refrigerator 52 according to the present invention that cools the cryopanel 51 to a predetermined cryogenic temperature, And a baffle 54 provided at the intake port, and a ring 55 for changing the exhaust speed of argon, nitrogen, hydrogen and the like.
- the operating temperature of the cryopanel 51 can be stably guaranteed over a long period of time. With this force, the performance of the cryopump 50 can be stably exhibited over a long period of time.
- FIG. 6 is a perspective view showing a schematic configuration of a magnetic field application type single crystal pulling apparatus using a regenerative refrigerator according to the present invention.
- the magnetic field applying type single crystal pulling apparatus 60 shown in FIG. 6 is a single crystal pulling section 61 having a material melting crucible, a heater, a single crystal pulling mechanism, etc., and a super magnetic field applying a static magnetic field to the raw material melt. It is composed of a conductive coil 62, a lifting mechanism 63 of a single crystal pulling section 61, and the like.
- the regenerative refrigerator 64 according to the present invention as described above is used for cooling the superconducting coil 62.
- 65 is a current lead
- 66 is a heat shield plate
- 67 is a helium container.
- the magnetic field application type single crystal pulling device 60 using the regenerative refrigerator 64 since the operating temperature of the superconducting coil 62 can be stably guaranteed over a long period of time, the single crystal A good magnetic field that suppresses convection of the raw material melt can be obtained over a long period of time. With this force, the performance of the magnetic field application type single crystal pulling apparatus 60 can be stably exhibited over a long period of time.
- the amount of copper and other metal components with respect to the rare earth component is appropriately adjusted, or H o having a high volume specific heat peak in an extremely low temperature region.
- C u Since some of the constituents of the magnetic material are replaced by other rare earth elements or transition metal elements, the temperature position of the volume specific heat peak moves to a lower temperature side and the half width of the specific heat peak expands.
- a regenerator material having good specific heat characteristics can be obtained.
- the refrigerator of the present invention using such a regenerative material for extremely low temperatures can maintain excellent refrigerating performance with good reproducibility over a long period of time.
- the MRI apparatus, cryopump, superconducting magnet for magnetic levitation train, and magnetic field applying type single crystal pulling apparatus of the present invention having such a refrigerator can exhibit excellent performance over a long period of time. .
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Hard Magnetic Materials (AREA)
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE69813767T DE69813767T2 (de) | 1997-10-20 | 1998-10-20 | Kältespeicherndes material und kältespeichernder kühlschrank |
EP98947963A EP0947785B1 (en) | 1997-10-20 | 1998-10-20 | Cold-accumulating material and cold-accumulating refrigerator |
US09/331,157 US6334909B1 (en) | 1998-10-20 | 1998-10-20 | Cold-accumulating material and cold-accumulating refrigerator using the same |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP28720097 | 1997-10-20 | ||
JP9/287200 | 1997-10-20 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1999020956A1 true WO1999020956A1 (en) | 1999-04-29 |
Family
ID=17714369
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP1998/004749 WO1999020956A1 (en) | 1997-10-20 | 1998-10-20 | Cold-accumulating material and cold-accumulating refrigerator |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0947785B1 (ja) |
CN (1) | CN1174200C (ja) |
DE (1) | DE69813767T2 (ja) |
WO (1) | WO1999020956A1 (ja) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002249763A (ja) * | 2000-07-18 | 2002-09-06 | Toshiba Corp | 蓄冷材,その製造方法およびその蓄冷材を用いた冷凍機 |
WO2018199278A1 (ja) * | 2017-04-28 | 2018-11-01 | 株式会社三徳 | HoCu系蓄冷材並びにこれを備えた蓄冷器及び冷凍機 |
Families Citing this family (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4551509B2 (ja) * | 1998-12-28 | 2010-09-29 | 株式会社東芝 | 蓄冷材および蓄冷式冷凍機 |
JP4104004B2 (ja) * | 2002-03-22 | 2008-06-18 | 住友重機械工業株式会社 | 蓄冷型極低温冷凍機 |
JP5127226B2 (ja) * | 2004-08-25 | 2013-01-23 | アルバック・クライオ株式会社 | 蓄冷器及びクライオポンプ |
JP2006242484A (ja) * | 2005-03-03 | 2006-09-14 | Sumitomo Heavy Ind Ltd | 蓄冷材、蓄冷器及び極低温蓄冷式冷凍機 |
GB0519843D0 (en) | 2005-09-29 | 2005-11-09 | Univ Cambridge Tech | Magnetocaloric refrigerant |
CN103773995B (zh) * | 2014-02-13 | 2017-09-15 | 北京科技大学 | 一种磁性蓄冷材料 |
CN112251199B (zh) * | 2014-09-25 | 2021-11-26 | 株式会社东芝 | 稀土类蓄冷材料粒子、使用了该粒子的冷冻机、超导磁铁、检查装置及低温泵 |
CN108981217A (zh) * | 2018-06-04 | 2018-12-11 | 中船重工鹏力(南京)超低温技术有限公司 | 蓄冷材料及采用该蓄冷材料的蓄冷式低温制冷机 |
RU2771034C1 (ru) * | 2018-09-28 | 2022-04-25 | Кабусики Кайся Тосиба | Материал для аккумуляции холода, рефрижератор, устройство, включающее сверхпроводящую катушку и способ изготовления материала для аккумуляции холода |
CN110440475A (zh) * | 2019-07-23 | 2019-11-12 | 中船重工鹏力(南京)超低温技术有限公司 | 抗氧化蓄冷材料及采用该蓄冷材料的蓄冷式低温制冷机 |
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US5593517A (en) * | 1993-09-17 | 1997-01-14 | Kabushiki Kaisha Toshiba | Regenerating material and refrigerator using the same |
EP0882938B1 (en) * | 1996-02-22 | 2004-11-03 | Kabushiki Kaisha Toshiba | Regenerator material for very low temperature use |
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- 1998-10-20 EP EP98947963A patent/EP0947785B1/en not_active Expired - Lifetime
- 1998-10-20 DE DE69813767T patent/DE69813767T2/de not_active Expired - Fee Related
- 1998-10-20 WO PCT/JP1998/004749 patent/WO1999020956A1/ja active IP Right Grant
- 1998-10-20 CN CNB988026708A patent/CN1174200C/zh not_active Expired - Fee Related
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JPH01310269A (ja) * | 1988-02-02 | 1989-12-14 | Toshiba Corp | 蓄熱材料および低温蓄熱器 |
JPH02298765A (ja) * | 1988-11-09 | 1990-12-11 | Mitsubishi Electric Corp | 多段式蓄冷型冷凍機及びそれを組み込んだ冷却装置 |
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Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002249763A (ja) * | 2000-07-18 | 2002-09-06 | Toshiba Corp | 蓄冷材,その製造方法およびその蓄冷材を用いた冷凍機 |
WO2018199278A1 (ja) * | 2017-04-28 | 2018-11-01 | 株式会社三徳 | HoCu系蓄冷材並びにこれを備えた蓄冷器及び冷凍機 |
JP6495546B1 (ja) * | 2017-04-28 | 2019-04-03 | 株式会社三徳 | HoCu系蓄冷材並びにこれを備えた蓄冷器及び冷凍機 |
US11370949B2 (en) | 2017-04-28 | 2022-06-28 | Santoku Corporation | HoCu-based cold-storage material, and cold-storage device and refrigerating machine each equipped therewith |
Also Published As
Publication number | Publication date |
---|---|
EP0947785B1 (en) | 2003-04-23 |
EP0947785A4 (en) | 2000-06-07 |
EP0947785A1 (en) | 1999-10-06 |
DE69813767T2 (de) | 2004-02-12 |
CN1248319A (zh) | 2000-03-22 |
CN1174200C (zh) | 2004-11-03 |
DE69813767D1 (de) | 2003-05-28 |
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