Abstract:
An air conditioning system includes at least a magnetic disc disposed in parallel along a rotary shaft thereof, permanent magnets installed within rotational radii of the respective magnetic discs, and applying magnetic fields to the magnetic disc rotating within a predetermined section, a heat exchanger for heating installed on a side of the permanent magnets, and having at least a heat radiation fin, and a heat exchanger for cooling installed on a side opposite the permanent magnets, and having at least a heat absorption fin. The air conditioning system has a simple structure, is safe from the fear of environmental pollution, and is suitable for a next-generation air conditioning system to be applied to a hybrid or electric automobile because it does not use engine heat or a refrigerant

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to Korean Application No. 10-2008-0056262, filed on Jun. 16, 2008, the entire contents of which is incorporated herein by this reference for all purposes. 
       BACKGROUND OF THE INVENTION 
       [0002]    (1) Field of the Invention 
         [0003]    The present invention relates, in general to an air conditioning system and, more particularly, to an air conditioning system for a motor vehicle using a magnetocaloric effect, 
         [0004]    (2) Description of the Related Art 
         [0005]    A magnetocaloric effect refers to a phenomenon that the temperature of a ferromagnetic material is increased when a strong magnetic field is applied to the ferromagnetic material on the outside, while the temperature of the ferromagnetic material is decreased when the magnetic field is eliminated. 
         [0006]    This magnetocaloric effect results from an entropy conservation law. As illustrated in  FIG. 1 , when a ferromagnetic material  1  is magnetized by a magnetic field generated from an external magnetic object  2 , the ferromagnetic material is subjected to spin alignment reduction in magnetic entropy, increase in atomic lattice entropy (increase in vibration of an atomic lattice) according to a total entropy conservation law, and generation of heat. In contrast, when the magnetic field applied to the ferromagnetic material  1  is eliminated, the ferromagnetic material is subjected to reduction in the atomic lattice entropy, and thus the temperature of the ferromagnetic material is decreased. 
         [0007]    Meanwhile, in the case of a current air conditioning system for a motor vehicle, the heat from an engine is used for heating an interior of the motor vehicle. However, due to a fear of oil exhaustion and environmental pollution, many efforts are made to develop a hybrid automobile or an electric automobile in various countries around the world. Thus, there is a practical need to displace the conventional heating system of the motor vehicle using the engine heat with another system. Further, in order to cool the interior of the motor vehicle, an ammonia-based gas called R-134a is mainly used. This refrigerant incurs environmental issues such as disruption of an ozone layer, and requires many additional devices such as a compressor, a condenser, a refrigerant pipe, a heater hose, and so on. As such, it is absolutely need to develop a so-called magnetic air conditioning system using the magnetocaloric effect from the viewpoint of reduction in cost and weight and environmental conservation. 
         [0008]    The information disclosed in this Background of the Invention section is only for enhancement of understanding of the background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art that is already known to a person skilled in the art. 
       SUMMARY OF THE INVENTION 
       [0009]    Accordingly, various embodiments of the present invention has been made keeping in mind the above problems occurring in the related art and an object of the present invention is to provide a an air conditioning system, particularly for a motor vehicle, using a magnetocaloric effect which has no chance of environmental pollution and does not require additional devices. 
         [0010]    According to one aspect of the present invention, there is provided an air conditioning system, which may comprise: at least a magnetic disc disposed in parallel along a rotary shaft thereof, magnets installed within rotational radii of the respective magnetic discs, and applying magnetic fields to the magnetic disc, wherein the magnet is fixed; a heat exchanger for heating installed on a side of the magnets, and having at least a heat radiation fin; and a heat exchanger for cooling installed on a side opposite the magnets, and having at least a heat absorption fin. The magnet may be a permanent magnet, superconductive magnet or an electromagnet. The magnetic disc may be made of a ferromagnetic material. The rotary shaft may be configured to move in an axial direction thereof and thereby a desired air conditioning temperature can be controlled through adjusting magnetic flux density of the magnet. 
         [0011]    Magnetic object pairs may be installed on the upper and lower circumference of the magnetic disc corresponding to the magnet. The rotary shaft is configured to be rotatable within a predetermined angle and thus an area where the magnetic object pairs face the magnet can be adjusted by rotating the magnetic disc around the rotary shaft. 
         [0012]    According to another aspect of the present invention, at least one magnetic object pair may be installed on an outer circumference of the magnetic disc in a diagonal direction thereof and at least one pair of the magnets is spaced apart from the magnetic object pair, and applying magnetic fields to the magnetic object pair within a predetermined angle, wherein the magnetic disc is configured to be able to reciprocate in an axial direction thereof. 
         [0013]    At least one magnetic object pair may be installed on an outer circumference of the magnetic disc in a diagonal direction thereof and at least one pair of the magnets is spaced apart from the magnetic object pair, and applying magnetic fields to the magnetic object pair within a predetermined angle, wherein the magnetic disc is configured to be able to rotate around the rotary shaft thereof at a predetermined angle. 
         [0014]    A heating channel and a cooling channel may be partitioned by a partition wherein the heat exchanger for heating is disposed on the heating channel, and the heat exchanger for cooling is disposed on the cooling channel. A common fan may be installed upstream the heat exchangers in order to ventilate both the heating channel and the cooling channel, wherein the partition downstream the heat exchangers includes a temperature door. Fans may be installed upstream the heat exchangers in order to feed air each heat exchanger. 
         [0015]    According to another aspect of the present invention an air conditioning system may comprise at least a hollow magnetic disc configured to rotate; magnets installed within rotational radii of the respective magnetic discs, and applying magnetic fields to the magnetic disc, wherein the magnets are fixed, an adiabatic partition installed in each magnetic disc so as not to be rotated together with each magnetic disc, and partitioning an interior of each magnetic disc into a space of a magnet side and a space opposite the magnet side; a heating channel causing a fluid to be fed into the magnetic discs, to pass through the magnet side, and to exchange heat at a heat exchanger for heating; and a cooling channel causing a fluid to be fed into the magnetic discs, to pass through a side opposite the magnet side, and to exchange heat at a heat exchanger for cooling. The magnet may be a permanent magnet superconductive magnet or an electromagnet. The magnetic disc may be made of a ferromagnetic material. 
         [0016]    At least one magnetic object pair may be installed on an outer circumference of the magnetic disc in a diagonal direction thereof and at least a pair of magnets is spaced apart from the magnetic object pair, and applying magnetic fields to the magnetic object pair within a predetermined angle, wherein the magnetic disc is configured to be able to reciprocate in an axial direction thereof. At least one magnetic object pair may be installed on an outer circumference of the magnetic disc in a diagonal direction thereof and at least a pair of magnets is spaced apart from the magnetic object pair, and applying magnetic fields to the magnetic object pair within a predetermined angle, wherein the magnetic disc is configured to be able to rotate around the rotary shaft thereof at a predetermined angle. 
         [0017]    According to a further aspect of the present invention an air conditioning system may comprise: a movable cylinder configured to reciprocate in an axial direction thereof; at least one magnetic object pair installed on an outer circumference of the movable cylinder in a diagonal direction; and at least one permanent magnet pair spaced apart from the magnetic object pair, and applying magnetic fields to the magnetic object pair within a predetermined section, wherein an area where the magnetic object pair faces the permanent magnet pair is adjusted by rotating the movable cylinder around a shaft thereof at a predetermined angle. 
         [0018]    As apparent from the above description, the air conditioning system is safe from the fear of environmental pollution, has a simple structure, and does not require additional devices to reduce costs. 
         [0019]    Further, the air conditioning system is suitable for a next-generation air conditioning system to be applied to a hybrid or electric automobile because it does not use engine heat or a refrigerant. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    The above and other features of the present invention will now be described in detail with reference to certain exemplary embodiments thereof illustrated the accompanying drawings which are given hereinbelow by way of illustration, and thus are not limitative of the present invention and wherein: 
           [0021]      FIG. 1  is a schematic view explaining theory of a magnetocaloric effect; 
           [0022]      FIG. 2  is an perspective view explaining the basic configuration of an air conditioning system in accordance with the present invention; 
           [0023]      FIG. 3  is a partial cross-sectional view taken along the ling A-A of  FIG. 2 ; 
           [0024]      FIG. 4  is a schematic view explaining a method of adjusting a temperature of the air conditioning system of  FIG. 2 ; 
           [0025]      FIG. 5  illustrates an application of the air conditioning system of  FIG. 2 ; 
           [0026]      FIG. 6  illustrates another application of the air conditioning system of  FIG. 2 ; 
           [0027]      FIG. 7  illustrates another air conditioning system in accordance with the present invention; 
           [0028]      FIG. 8  illustrates another air conditioning system in accordance with the present invention; and 
           [0029]      FIG. 9  is a top plan view illustrating the air conditioning system of  FIG. 8 . 
       
    
    
       [0030]    It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various preferred features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment. 
         [0031]    In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0032]    Reference will now be made in greater detail to an air conditioning system according to exemplary embodiments of the present invention with reference to the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings and the description to refer to the same or like parts. 
         [0033]    Referring to  FIGS. 2 and 3 , an air conditioning system according to the first embodiment has an air-cooled structure in which a permanent magnet  20  is installed on one side of each rotary magnetic disc  10 , each magnetic disc  10  absorbs or radiates heat according to a rotating angle thereof, and this heat heats or cools air introduced from the outside by means of heat exchangers  30  and  40 . 
         [0034]    The magnetic discs  10  are disposed in parallel along a rotary shaft  11 , has the shape of an annular ring, the central portion of which is open. The central portion of each magnetic disc  10  is provided with a crisscross frame such that the magnetic discs  10  can share the rotary shaft  11  with each other. This magnetic disc  10  is made of a ferromagnetic material showing a strong magnetocaloric effect at an approximately room temperature. One example of the ferromagnetic material includes gadolinium, which is a rare-earth metal having high magnetic susceptibility, or a GdSiGe based mixture. 
         [0035]    Each permanent magnet  20  is installed within a rotational radius of each magnetic disc  10 , and thus applies a magnetic field to each magnetic disc  10  rotating within a predetermined section. Each permanent magnet  20  is provided with a receiving slot opposite sides of which serves as N and S poles of each permanent magnet  20 . Each rotary magnetic disc  10 , which is located in the receiving slot of each permanent magnet  20 , intersects the magnetic field of each permanent magnet  20  at a right angle. Preferably, the magnitude of the magnetic field applied to each magnetic disc  10  by each permanent magnet  20  must be more than 2 tesla. Alternatively, a superconductive magnet or an electromagnet may be naturally used instead of the permanent magnet  20 . 
         [0036]    The heat exchangers are made up of the heat exchanger  30  for heating and the heat exchanger  40  for cooling. The heat exchanger  30  for heating is installed on the side of the permanent magnets  20 , and includes at least a heat radiation fin  31 . The heat exchanger  40  for cooling is installed on the side opposite the heat exchanger  30  for heating, and includes at least a heat absorption fin  41 . Parts of the rotary magnetic discs  10 , which are introduced into and heated inside the receiving slots of the permanent magnets  20 , radiate heat through the beat exchanger  30  for heating, and other parts, which come out of and is cooled outside the receiving slots, absorb heat from the heat exchanger  40  for cooling. 
         [0037]    A method of adjusting temperature of the air conditioning system will be described with reference to  FIG. 4 . Magnetic flux density is a little different depending on a position in the receiving slot of each permanent magnet  20 . 
         [0038]    In detail, the magnetic flux density is relatively high in the proximity of the N pole or the S pole, whereas it is somewhat low between the N pole and the S pole. Thus, as illustrated in  FIG. 4 , if the rotary shaft  11  of the magnetic discs  10  is adapted to be able to move in an axial direction thereof and then to adjust an amount of intersecting magnetic flux of the magnetic discs  10 , the temperature of the air conditioning system can be adjusted. In the case of the permanent magnets, the intensity of the magnetic field cannot be arbitrarily adjusted. However, the aforementioned method makes it possible to control the temperature, particularly to adjust a desired air-conditioning temperature. In various embodiments, the air conditioning system may have a structure in which at least one magnetic object pair (not shown) is installed on the upper and lower circumference of the rotary magnetic disc  10  corresponding to the permanent magnet  20 . Accordingly, as the rotary magnetic disc  10  is rotated around the rotary shaft  11  with a predetermined angle, an area where the magnetic object pair faces the permanent magnet  20  can be adjusted and thus a desired air conditioning temperature can be adjusted through adjustment of an amount at which the permanent magnet  20  intersects magnetic flux. 
         [0039]    An application of the aforementioned air conditioning system will be described with reference to  FIGS. 5 and 6 . 
         [0040]    As illustrated in  FIG. 5 , the air conditioning system includes a heating channel and a cooling channel, which are partitioned by a partition  61 . The heat exchanger  30  for heating is assigned to the heating channel, whereas the heat exchanger  40  for cooling is assigned to the cooling channel. A common fan  50  is installed upstream the heat exchangers  30  and  40  in order to ventilate both the heating channel and the cooling channel, and a temperature door  70  is installed on the partition downstream the heat exchangers  30  and  40 . Alternatively, the temperature door  70  may be installed upstream the heat exchangers  30  and  40 . In this case, the air flowing through the heating channel and the air flowing through the cooling channel are mixed with each other from the viewpoint of air flow. A reference number  60 , which has not been yet described, indicates a case corresponding to a conventional heating ventilation and air conditioning (HVAC) housing. 
         [0041]    Alternatively, as illustrated in  FIG. 6 , the fans  50  may be separately installed upstream the heat exchangers  30  and  40 . In this case, the temperature door  70  is removed. 
         [0042]    Unlike the air-cooled type described above, the air conditioning system of various embodiments may be designed in a water-cooled type. 
         [0043]    Referring to  FIG. 7 , the exemplary air conditioning system is similar to that described above in that a permanent magnet  200  for applying a magnetic field is installed on one side of each magnetic disc  200  rotated around a rotary shaft  201  in a predetermined angle, but it is different from that described above in that each magnetic disc  200  has a hollow structure without opening the central portion thereof. 
         [0044]    As for an internal structure of each magnetic disc  200 , an inner wall of each hollow magnetic disc  200  is provided with a casing  210 , which prevents contact with water and has good heat transferability. The casing  210  is provided therein with an adiabatic partition  220 . A vertical part of the adiabatic partition  220  partitions an interior of the casing  210  into two spaces, one of which is located on the side of a permanent magnet and the other on the side opposite the permanent magnet. A horizontal part of the adiabatic partition  220  increases a heat transfer contact area between a fluid flowing in the casing  210 . 
         [0045]    Meanwhile, the magnetic disc  200  and its casing  210  are rotated together around the rotary shaft  201 , but the adiabatic partition  220  is not rotated together, namely is fixed. Part of the rotary magnetic disc  200  which is located on the side of the permanent magnet  230  always generates heat, and the opposite part always absorbs heat. Thus, in the case in which the adiabatic partition  220  is fixed despite the rotation of the magnetic disc  200 , water is allowed to flow only to the permanent magnet (i.e. heating channel) inside the magnetic disc during heating operation, and to flow only the opposite side (i.e. cooling channel) during cooling operation. Of course, because the magnetic disc  200  is rotated relative to the adiabatic partition  220 , the water may be infiltrated from the heating channel to the cooling channel or vice versa through a gap between the adiabatic partition  220  and the magnetic disc  200 , more particularly between the adiabatic partition  220  and the casing  210 . 
         [0046]    As described above, the magnetic flux density is relatively high in the proximity of the N pole or the S pole, whereas it is somewhat low between the N pole and the S pole. Thus, as illustrated in  FIG. 7 , if the rotary shaft  201  of the magnetic discs  200  is adapted to be able to move in an axial direction thereof, and then to adjust an amount of intersecting magnetic flux of the magnetic discs  200 , the temperature of the air conditioning system can be adjusted. In another aspect the air conditioning system of various exemplary embodiments may have a structure in which at least one magnetic object pair (not shown) is installed on the upper and lower circumference of the magnetic disc  200  corresponding to the permanent magnet  230 . The magnetic disc  200  can be rotated around the rotary shaft  201  in a predetermined angle. Since an area where the magnetic object pair faces the permanent magnet  230  can be adjusted by rotating the magnetic disc  200  around the rotary shaft  201  at the predetermined angle, a desired air conditioning temperature can be adjusted. 
         [0047]    In this manner, the hot water having passed through the heating channel in the magnetic disc  200  radiates heat at the heat exchanger for heating, and then flows into a pump, while the cold water having passed through the cooling channel absorbs heat at the heat exchanger for cooling, and then flows into the pump. The pump circulates the water along each channel again. 
         [0048]    Unlike the exemplary embodiments described above, the ferromagnetic material of the magnetic disc may be configured to reciprocate with respect to the permanent magnet. 
         [0049]    As illustrated in  FIG. 8 , the air conditioning system of various embodiments may have a structure in which at least one magnetic object pair  110  is installed on the outer circumference of a movable cylinder  100 , i.e., a magnetic disc, configured to reciprocate in an axial direction thereof, and in which at least one permanent magnet pair  120  is installed outside the magnetic object pair  10  corresponding to the magnetic object pair  110 . The magnetic object pair  110  is installed on the outer circumference of the movable cylinder  100  in a diagonal direction, and the permanent magnet pair  120  is spaced apart from the magnetic object pair  110 , and applies a magnetic field to the other permanent magnet pair  120  through a portion of the magnetic object pair  110  which reciprocates along the axial direction of the movable cylinder  100  as the movable cylinder  100  moves along its axial direction which changes the magnetic flux density. 
         [0050]    Meanwhile, as illustrated in  FIG. 9 , the movable cylinder  100  can be rotated around a central shaft  101  in a predetermined angle. Thus, an area where the magnetic object pair  110  faces the permanent magnet pair  120  can be adjusted by rotating the movable cylinder  100  around the central shaft  101  at a predetermined angle. Thereby, a desired air conditioning temperature can be adjusted. As described above, the air conditioning temperature is controlled through adjustment of an amount at which the magnetic object pair  10  intersects magnetic flux. 
         [0051]    The heat exchange and circulation of the air conditioning system of various embodiments can be varied on the basis of the aforementioned embodiments and any well-known technology. 
         [0052]    Although exemplary embodiments of the present invention have been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.