Magnetic refrigerating device and magnetic refrigerating method

Abstract

A magnetic refrigerating device includes: at least one set of double-structured Halbach type magnet including a ring-shaped inner Halbach type magnet and a ring-shaped outer Halbach type magnet which are coaxially arranged one another so that a magnetic field generated by the inner Halbach type magnet is superimposed with a magnetic field generated by the outer Halbach type magnet; a magnetic refrigerant or a magnetic refrigeration working chamber including the magnetic refrigerant therein disposed in a bore space of the inner Halbach type magnet; and a rotating mechanism to rotate the outer Halbach type magnet while the inner Halbach type magnet is stationed.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2006-265833, filed on Sep. 28, 2006; the entire contents of which are incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a magnetic refrigeration device and a magnetic refrigeration method which utilize a permanent magnet as a magnetic field-generating means and particularly, to a magnetic refrigeration device and a magnetic refrigeration method which can reduce heat flow into the magnetic refrigeration working chamber when the magnetic refrigeration material is magnetizing and demagnetizing.[0004]2. Description of the Related Art[0005]When the intensity of magnetic field to be applied is changed for a certain magnetic material, the temperature of the magnetic material also changes, which is called as a “magneto-caloric effect”. Physically, the degre...

AI Technical Summary

Benefits of technology

[0023]It is an object of the present invention, in view of the above-described problems relating to the magnetic refrigeration device using the permanent magnet as a magnetic field-generating means, to provide a small and simple magnetic refrigeration device and a magnetic refrigerating method which can reduce heat loss when a magnetic field is applied to and removed from the magnetic refrigerant or the magnetic refrigeration working chamber containing the magnetic refrigerant.

[0027]As a result, the heat generated from the friction against the permanent magnet is not flowed into the magnetic refrigerating device so that the refrigerating efficiency can be enhanced.

[0028]In an embodiment, the heat transfer is conducted through a heat transfer medium which can realize a direct heat exchange between the magnetic refrigerant and the heat transfer medium. According to the heat transfer medium, the heat transfer can be easily conducted.

[0029]In another embodiment, the magnetic refrigerant is rendered particulate. In this case, when the heat transfer is conducted with the heat transfer medium, the heat exchange area between the magnetic refrigerant and the heat transfer medium can be increased so as to enhance the heat transfer efficiency, that is, the refrigerating efficiency.

[0033]According to the aspect of the present invention can be provided a small and simple magnetic refrigerating device and a magnetic refrigerating method without environment risk which can reduce heat loss when a magnetic field is applied to and removed from the magnetic r refrigerant or the magnetic refrigeration working chamber containing the magnetic refrigerant.

Problems solved by technology

However, in the refrigeration technique using the gas compressing and expanding cycle such as a chlorofluorocarbon (CFC) or hydrochlorofluorocarbon (HCFC) or hydrofluorocarbon (HFC) gas, there are some problems relating to the ozone layer destruction or the global warming caused by the environmental exhaust of those gasses.

However, the magnetic refrigeration system is grown in size.

The intended magnetic refrigeration requires the cryogenic condition of extreme lower temperature environment than the intended refrigerating environment, which is paradox in engineering application.

Therefore, the magnetic refrigeration system becomes complicated, grows in size and requires high operation cost.

However, since it is difficult to generate the high magnetic field in the intensity of 5 T by using the permanent magnet, the intensity of the magnetic field in a practical adaptation becomes smaller than the intensity of the magnetic field by using the SM.

The bulk of permanent magnet is also a large heat bath so that when the heat is flowed, which means heat loss, into the magnetic refrigerant or the magnetic refrigeration working chamber containing the magnetic refrigerant, the refrigeration efficiency of the magnetic refrigerating operation is deteriorated, which means a significant disincentive for the refrigeration.

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