WO2008150108A2

WO2008150108A2 - Supercooling apparatus

Info

Publication number: WO2008150108A2
Application number: PCT/KR2008/003141
Authority: WO
Inventors: Su-Cheong Kim; Jong-Min Shin; Deok-Hyun Youn; Cheol-Hwan Kim; Won-Young Chung; Hoon-Bong Lee
Original assignee: Lg Electronics, Inc.
Priority date: 2007-06-04
Filing date: 2008-06-04
Publication date: 2008-12-11
Also published as: WO2008150108A3

Abstract

A supercooling apparatus is capable of storing items in a supercooled state stably for an extended period of time through energy control. The supercooling apparatus includes an insulating member having a storage space formed inside to store an item, and an electrode unit (50c) installed insidide the storage space.

Description

SUPERCOOLING APPARATUS

Technical Field

[1] The present invention relates to a supercooling apparatus for storing items in a supercooled state stably for an extended period of time through energy control. Background Art

[2] A term "supercooling" describes a phenomenon that melt or solid does not change even after it is cooled down to a temperature lower than the phase transition temperature at equilibrium state. In general, every material has its own stable state at a given temperature, so if temperature changes gradually, atoms of the substance keep abreast with the changes of temperature while maintaining its stable state at each temperature. However, if temperature changes abruptly, there is not enough time for the atoms to get into a stable state corresponding to each temperature. What happens then is the atoms either keep the stable state at a start temperature, or partially change to a state at a predetermined end temperature then stop.

[3] For example, when water is cooled slowly, it does not freeze for some time even though the temperature is below 0 °C. However, when an object becomes a supercooled state, it is a sort of metastable state where the unstable equilibrium state breaks easily even by a very small stimulus or minor external disturbance, so the object easily transits to a more stable state. That is to say, if a small piece of the material is put into a supercooled liquid, or if the liquid is subject to impact on a sudden, it starts being solidified immediately and temperature of the liquid is raised to a freezing point, maintaining a stable equilibrium state at the temperature.

[4] Normally, foods like vegetables, fruits, meats, or beverages are kept either refrigerated or frozen to retain freshness. Those foods contain liquid such as water. When the liquid is cooled below the phase transition temperature, it transits to a solid phase at one point.

[5] Although an item like water can be preserved for a short period of time, moisture- containing foods need to stay in a supercooled state or non-frozen state much longer for long-term storage without losing freshness and high quality of the foods. Disclosure of Invention Technical Problem

[6] The present invention is conceived to solve the aforementioned problems in the prior art. An object of the present invention is to provide a supercooling apparatus capable of stably maintaining a supercooled state for a stored item for an extended period of time. [7] Another object of the present invention is to provide a supercooling apparatus capable of stably maintaining a supercooled state for a stored item at a lowest possible temperature. [8] Still another object of the present invention is to provide a supercooling apparatus having an insulation member such that AC power is applied only to electrodes to generate an electric field in a storage space, without the help of a separate electric field shielding device. [9] Yet another object of the present invention is to provide a supercooling apparatus that generates an electric field in plural drections of a storage, so that a broader space can be influenced by the electric field.

Technical Solution [10] According to an aspect of the present invention, there is provided a supercooling apparatus, induing: an insulating member having a storage space formed inside to store an item; a refrigeration cycle for cooling the storage space; and an electrode unit installed inside the storage space. [11] Preferably, the electrode unit is a plane with one side mounted at a lateral face of the insulating member. [12] Preferably, the electrode unit is separated at a fixed distance from at least a pair of symmetric lateral faces of the insulating member. [13] Another aspect of the invention provides a supercooling apparatus induing; a storage for storing an item inside; a refrigeration cycle for cooling the storage; and an electrode unit mounted in the storage, for generating an electric field in at least two directions.

[14] Preferably, inner faces of the storage include an insulating member.

[15] Preferably, the electrode unit is separated at a fixed distance from at least a pair of symmetric lateral faces of the insulating member.

Advantageous Effects [16] The supercooling apparatus with the above configαration takes energy out of an item by a cooling operation yet supplies energy in another way to let molecules in a target liquid to be supercooled to db at least one of rotation, vibration, and translation movements, preventing the occurrence of phase transition. Therefore, a stored item can be kept in a supercooled state stably for an extended period of time at a lowest possible temperature.

[17] The supercooling apparatus of the present invention is capable of stably maintaining a supercooled state for a stored item at a lowest possible temperature.

[18] The supercooling apparatus of the present invention includes an insulation member such that AC power is applied only to electrodes to generate an electric field in a storage space, without the help of a separate electric field shieldng device.

[19] The supercooling apparatus of the present invention creates an electric field in plural directions of a storage. Accordngly, an uniform electric field is applied to stored items, and a user can change the position of a stored item as desired. Brief Description of the Drawings

[20] Fig. 1 conceptually shows the normal electrode structure of a supercooling apparatus to maintain a supercooled state;

[21] Fig. 2 is a graph reflecting a supercooling phenomenon that occurs in the supercooling apparatus based on Fig. 1;

[22] Fig. 3 shows one embodiment of the supercooling apparatus based on Fig. 1;

[23] Fig. 4 conceptually shows the enhanced electrode structure of a supercooling apparatus to maintain a supercooled state;

[24] Fig. 5 and Fig. 6 show, respectively, removable shelves with enhanced electrode structure wired thereon;

[25] Fig. 7 shows one embodiment of a supercooling apparatus provided with a removable shelf according to Fig. 5 or Fig. 6ζ

[26] Fig. 8 shows another cross-sectional view of Fig. 7;

[27] Fig. 9 and Fig. 10 show other embodiments of Fig. 7 or Fig. 8; and

[28] Fig. 1 1 is a block diagram of a supercooling apparatus according to the present invention.

[29]

Mode for the Invention

[30] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[31] When liquid such as water is cooled slowly, it obes not freeze for some time even though the temperature is below 0 °C. However, when an object becomes a supercooled state, it is a sort of metastable state where the unstable equilibrium state breaks easily even by a very small stimulus or minor external disturbance, so the object easily transits to a more stable state. That is to say, if a small piece of the material is put into a supercooled liquid, or if the liquid is subject to impact on a sudden, it starts being solidified immediately and temperature of the liquid is raised to a freezing point, maintaining a stable equilibrium state at the temperature.

[32] Even if the temperature is lower than the phase transition temperature at this time, the supercooled state can be maintained continuously as long as molecules are allowed to do at least one of the following: rotation, vibration, and translation constantly. In other words, if energy is supplied at the same time with the liquid cooling process (Le. offsetting the energy absorbed during the cooling process) and to inhibit phase transition from liquid to solid, the liquid phase can be maintained stably for an extended period of time even at temperature lower than the phase transition temperature.

[33] Fig. 1 is a conceptual view of the normal electrode structure of a supercooling apparatus to maintain a supercooled state.

[34] Referring to Fig. 1, a casing 1 includes two built-in electrodes 10a and 10b in opposite directions to each other with respect to a storage space S 1 of the casing 1. A power supply 2 is also provided to apply high-voltage AC to the electrodes 10a and 10b. When high-voltage AC from the power supply 2 is impressed to the electrodes 10a and 10b, an electric field is created in the storage space Sl between the electrodes 10a and 10b, supplying energy to the storage space Sl.

[35] As a cooling operation takes place in the storage space Sl according to a cooling cycle (not shown), heat energy is taken out of the storage space S 1 and another kind of energy (Le. electric field energy) can be supplied instead. This explains how water or moisture-containing food can be kept in the storage space S l for a long period of time in a stable, cooled state without being solidified or frozen even at the phase transition temperature^r below).

[36] Fig. 2 is a temperature-time graph showing how temperature changes as water gets cooled down in the supercooling apparatus of Fig. 1.

[37] Normally, phase transition occurs if water is cooled dawn below its phase transition temperature.

[38] For the experiment, 0.1/ of distilled water was put into the storage space S 1 of the casing 1 shown in Fig. 1, and the electrodes 10a and 10b having a wider surface than the storage space S 1 are arranged on opposite sides of the storage space S 1. The gap between the electrodes 10a and 10b is 20mm. The casing 1 is made out of an acrylic material, and slid into and cooled down in a refrigerating space (a refrigerating apparatus having no supplementary electric field generator besides the electrodes 10a and 10b) to which chilled air is uniformly dspersed.

[39] The power supply 2 applies 0.9IkV (6.76mA), 2OkHz AC to the electrodes 10a and

10b, and the inside temperature of a refrigerating space is about -7°C.

[40] As can be seen in Fig. 2, by supplying energy in form of the electric field, a supercooled state (non-frozen state) can be maintained stably for an extended period of time.

[41] Fig. 3 shows one embodiment of a supercooling apparatus based on HG. 1. In particular, the supercooling apparatus of Fig. 3 is an indirect cooling (e.g., fan cooling) type apparatus with a cooling cycle.

[42] The supercooling apparatus is constituted of a casing 110 which has one open side and a storage space A being partially divided by a shelf 130, and a daor 120 for opening or closing the open side of the casing 110. A refrigeration cycle 30 of the indirect cooling type super cooling apparatus includes a compressor 32 for compressing a refrigerant, an evaporator 33 for producing chilled air (jndcated by arrows) to cool the storage space A or a stored item, a fan 34 for forcibly circulating the produced chilled air, an inlet ^r suction) duct 36 for introducing the chilled air into the storage space A, and an outlet ^r discharge) duct 38 for leading the chilled air having passed through the storage space A to the evaporator 33. Although not shown, the refrigeration cycle 30 can fiirther include a condenser, a drier, an expansion unit, etc. For the supercooling apparatus, the refrigeration cycle can be embodied based on the drect cooling system as well as the indrect cooling system.

[43] Electrodes 50a and 50b are formed between inner faces 112a and 112c facing the storage space A and the outer faces of the casing 110. The electrodes 50a and 50b are arranged to face the storage space A from opposite sides, so that an electric field can be applied to the entire storage space A. The storage space A is formed between the electrodes 50a and 50b or at the center, being spaced apart from the ends of the electrodes 50a and 50b by a predetermined dstance in the inward drection, such that a uniform electric field may be applied to the storage space A or the stored item.

[44] The inlet duct 36 and the outlet duct 38 are formed in the inner face 1 12b of the casing 1 10. In addtion, surfaces of the inner faces 112a, 112b, and 112c of the casing 110 are made of a hydrophobic material such that the surface tension of water or moisture is reduced and ά) not freeze during the supercooling mode. Needless to say, the outer faces and the inner faces 1 12a, 1 12b, and 1 12c of the casing 1 10 are made of an insulating material to protect a user from the exposure to an electric shock generated from the electrodes 50a and 50b and at the same time, to prevent a stored item from coming into a drect electrical contact with the electrodes 50a and 50b via the inner faces 112a, 112b, and 112c. Although the indirect cooling type supercooling apparatus has been illustrated, it is evident that the present invention can be embodied in a drect cooling type supercooling apparatus as well.

[45] In case of forming an electric field by connecting the electrodes 50a and 50b in this way, the electric field may be formed in the space A between those two electrodes 50a, but it is formed on the upper and lateral sides of the electrode 50a and the lower and lateral sides of the electrode 50b as well. Therefore, in order to protect the user from the influence of the electric field, either an electric field shieldng device should be used, or an electric field shieldng member should be applied to the inside of the storage space or to the outside of the casing 110.

[46] Moreover, since the electric field is formed between the electrodes 50a and 50b, the electrode positions are inevitably limited. For example, the electrodes may be arranged at the upper and lower sides of the storage space as shown in Fig. 3, or at two opposite sides of the storage space. In case of the latter, the electrode positions are limited to symmetric positions on lateral faces of the storage space.

[47] This problem can be resolved by changing the electrode positions and wiring.

[48] Fig. 4 is a conceptual view of electrodes to supply energy to an item. In particular,

Fig. 5 and Fig. 6 illustrate flat boards (preferably shelves) on which electrodes can easily be installed. In case of Fig. 4, an electrode 20a in the middle is connected to a power supply, and the other part of the power supply is grounded (not shown) and high-voltage AC power is usually applied thereto. The electrode 20a is enclosed with an insulating member 20b. The storage space itself may become an insulating member, or an insulation member may be provided outside/inside the storage space casing. When an electric field is generated by electrodes in this way, a separate shieldng device is not necessary and there is less limitation to the electrode positions. Therefore, electrodes can be provided in form of a flat board or a wire installed at one lateral face of the insulating member.

[49] Figs. 5 and 6 illustrate that electrodes in form of a flat board, preferably a shelf, can be installed in the storage space or at one lateral face of the insulating member.

[50] Fig. 5 shows one example of a flat board inducing a planar electrode. With a typical shelf form, an electrically conductive thin film or plane 30a is placed inside the shelf. The conductive thin film or plane is mainly made of a metallic substance, particularly aluminum or copper for example. The conductive thin film or plane 30a is connected to ends of branches dvided from one wire at dfferent points from one another, and the other ends are selectively connected to the power supply through a plug 30b or the like. With this configiration, the same power is connected to miltispots of a thin film or plane, and a more uniform voltage can be applied to the plane (since the main goal is to apply a uniform voltage to the plane, the location of the wire or the number of wires being connected to the thin film or plane is for illustrative purposes only). This configiration makes it possible to create an electric field in a vertical direction, and the thusly formed electric field supplies energy to prevent the phase transition of an item £>r liquid) at the phase transition temperature or below.

[51] Fig. 6 shows one example of a plane inducing an electrode wire. An electrically conductive wire 30c is inserted into a shelf with a typical structure. An extremely thick coating for the wire is not desired because an electric field should be generated in a storage space when power is applied to the wire. Similar to the example of Fig. 5, both ends of the wire inside the shelf can selectively be connected with a power supply through a plug 30d.

[52] Under the same condtions, the longer the wire inside the shelf, the greater the electric field intensity becomes. Therefore, it is better to use a long wire inside the shelf (since the main goal is to increase the length of the wire, the wire pattern shown in Fig. 6 is for illustrative purposes only).

[53] It is evident to a person skilled in the art to which the present invention pertains that the shelves illustrated in Fig. 5 and Fig. 6 can easily be installed in a removable manner without the help of a special device, but simply by using a glide that is used for a supercooling apparatus like a refrigerator. When electrodes are laid out horizontally between the electrode and the electric field shielding member, an electric field is generated in at least two directions, e.g., up and down. The thusly formed electric field supplies energy to prevent the phase transition of an item £>r liquid) at the phase transition temperature or below.

[54] Fig. 7 shows one embedment of the supercooling apparatus capable of stably maintaining a supercooled state for an extended period of time.

[55] In particular, Fig. 7 illustrates an indrect cooling type refrigerator, which is constituted of a casing 110 having one open side and a storage space A being partially dvided by a shelf 130a, and a door 120 for opening or closing the open side of the casing 1 10. A refrigeration cycle 30 of the indrect cooling type refrigerator is constituted by a compressor 32 for compressing a refrigerant, an evaporator 33 for producing chilled air (indcated by arrows) to cool the storage space A or a stored item, a fan 34 for forcibly circulating the produced chilled air, an inlet duct 36 for in- troducing the chilled air into the storage space A, and an outlet duct 38 for leading the chilled air having passed through the storage space A to the evaporator 33. Although not shown, the refrigeration cycle 30 can farther include a condenser, a drier, an expansion unit, etc.

[56] An electrode unit 50c is formed at the shelf 130a partially dvidng the storage space. Preferably, the shelf is placed at a fixed dstance away from the opposite sides of the storage space, so that a uniform electric field can be created in the storage space or a stored item. The electrode unit 50c is installed, in a removable manner, at the supercooling apparatus, and the electrode unit 50c can be formed of a metallic sheet (thin film) or a wire as illustrated in Figs. 5 and 6. The electrode unit 50c is connected to a power supply (not shown) though a plug (not shown) to receive power, preferably high-voltage AC power. A guide (not shown) in a storage may be used to support the electrode unit, or the electrode unit may be arranged at a fixed dstance away from a pair of symmetric sides of an insulating member.

[57] The inlet duct 36 and the outlet duct 38 are formed in the inner face 112b of the casing 110. In addtion, surfaces of the inner faces 112a, 112b, and 112c of the casing 110 are made of a hydrophobic material such that the surface tension of water or moisture is reduced and ob not freeze during the supercooling mode. Needless to say, the outer faces and the inner faces 112a, 112b, and 112c of the casing 110 are made of an insulating material to prevent the leakage of an electric field. Likewise, the shelf 130a where the electrode 50c is formed is formed of an insulating member to protect a user from the exposure to an electric shock and at the same time, to inhibit foods on the shelf from coming in drect electrical contact with the flat board (thin film) or the wire. Although the indrect cooling type supercooling apparatus has been illustrated, it is evident that the present invention can be emboded in a drect cooling type supercooling apparatus as well.

[58] Fig. 8 is a front cross-sectional view of the supercooling apparatus in Fig. 7. The shelf 130a is fixed to both lateral faces 112d and 112e and inner face of the casing 110 for support.

[59] The electrode unit 50c is separated from the inner upper face 112a of the casing 110 by a dstance dl , and separated from the inner lower face 112c of the casing 110 by a dstance dl'. Here, dl and dl' have the same value, so a uniform electric field is generated in a vertical drection of the electrode unit 50c.

[60] Moreover, the electrode unit 50c is separated from one lateral face 112d of the casing 1 10 by a dstance d2, and separated from the other lateral face 1 12e of the casing 1 10 by a distance d2'. Here, d2 and d2' have the same value, so a uniform electric field is generated in a lateral direction of the electrode unit 50c.

[61] With the layout of the electrode unit 50c explained above, a symmetric electric field with respect to the electrode unit 50c is formed at the inner faces 112a and 112c of the casing. In like manner, a symmetric electric field with respect to the electrode unit 50c is formed at the inner faces 112d and 112e of the casing. One thing to notice is that the casing 110 itself has an electric field shielding Junction, so it is important that the electric field does not leak outside the casing 110. Meanwhile, it is evident to a person skilled in the art to which the present invention pertains that the shelf 130a including the electrode unit 50c can be removably installed with the help of a guide (not shown) available in a storage space.

[62] Fig. 9 and Fig. 10 show yet fiirther embodiments of Fig. 8. Referring to Fig. 9, a shelf 130b is fixed only to an inner lateral face 112b of a casing 110. An electrode unit 50c is separated from the inner faces 1 12a and 112c of the casing 110 by a fixed distance, and separated from the inner faces 112d and 112e of the casing 110 by the same£>r different) distance. With this layout of the electrode unit 50c, a symmetric electric field with respect to the electrode unit 50c is formed at the inner faces 112a and 112c of the casing. In like manner, a symmetric electric field with respect to the electrode unit 50c is formed at the inner faces 112d and 112e of the casing. The both sides of the shelf 130b can be separated from the inner faces 112d and 112e, so items of various sizes can be stored.

[63] Fig. 10 illustrates a case in which a support is added to the shelf of Fig. 9. Again, an electrode unit 50c is separated from the inner faces 1 12a and 112c of the casing 1 10 by a fixed distance, and separated from the inner faces 112d and 112e of the casing 110 by the same£>r different) distance. Meanwhile, the shelf 130b is supported from the bottom by a supporting unit 132 protruded from the lower lateral face 112c of the casing 110. In this structure, the shelf 130b including the electrode 50c may or may not be removable. Though not shown, it is evident to a person skilled in the art to which the present invention pertains that a supporting unit can be protruded from the upper lateral face 112a of the casing 110.

[64] The inlet duct 36 and the outlet duct 38 are omitted from the Figs. 8 through 10.

[65] Fig. 1 1 is a schematic block diagram to explain the operation method of a supercooling apparatus.

[66] A supercooling apparatus 100 includes a load detector 20 to detect state of the storage space, state of a stored item (not shown) put in the storage space, etc.; a re- frigeration cycle 30 to cool the storage space; a power generator 40 for generating voltage so that an electric field may be applied to the storage space; an electrode unit 50 for generating an electric field at the application of the generated voltage; a door sensor 60 for sensing an open/closed state of a obor (120 in Fig. 7); an input unit 70 through which a user inputs a desired refrigeration degree, whether to execute a supercooling mode, etc.; a display unit 80 for displaying an operation state of the supercooling apparatus 100; and a Micom 90 for executing the supercooling mode.

[67] In detail, the load detector 20 detects or stores the state of the storage space or the state of a stored item in the storage space, and provides it to the Micom 90. For example, the load detector 20 can store information on volume of the storage space as t he state of the storage space, or it can be used in the form of a thermometer to detect temperature of a stored item or in the form of one of a durometer, an amperemeter, a voltmeter, a weight scale, an optical sensor £>r laser sensor) or a pressure sensor to check the presence of an item in the storage space. Particularly, an amperemeter or a voltmeter is usefiil as the load detector 20 because both show a change in the total resistance value of an electric field-dependent resistor when the storage space is empty and when there is any stored item in the storage space. To be short, the changed resistance value tells whether there is an item kept in the storage space. Based on the resistance value provided from the load detector 20, the Micom 90 finds out the amount and moisture content of the stored item(s) and identifies a kind of the stored item having the moisture content accordingly.

[68] The refrigeration cycle 30 can be classified into an indrect cooling type and a direct cooling type, depending on a cooling method used to store items.

[69] The power generator 40 generates an AC voltage according to a predetermined magnitude and frequency. The power generator 40 can produce an AC voltage by varying the magnitude and/or the frequency of a given voltage. Particularly, the power generator 40 applies to the electrode unit 50 an AC voltage based on a preset value (the magnitude of a voltage, the frequency of a voltage, etc.) from the Micom 90, so that an electric field may be applied to the storage space.

[70] The electrode unit 50 is a means for converting the AC voltage from the power generator 40 into an electric field and applying the electric field to the storage space. In general, a flat board (thin layer) or wire made of copper, platinum, or aluminum is used as the electrode unit 50. Since a high-frequency AC voltage in the electrode unit 50 induces an electric field in the storage space or the stored item(s), the direction of the electric field changes at regilar time intervals by a given frequency. In the presence of an electric field having such properties, a water molecule composed of oxygen (O) with the (-) polarity and hydrogen (H) with the (f) polarity continuously vibrates, rotates, or translates. This is how water molecules are not crystallized, but maintain a liquid phase even at the phase transition temperature or below. Since it is not safe for any one to touch, with his or her hand, the electrode unit 50 to which power from the power generator 40 is applied, the electrode unit 50 should be enclosed with a shieldng member. This configαration prevents an electric shock, and when the door is closed, the electric field is formed in at least two directions of the electrode unit, maintaining a supercooled state. In particular, the present invention varies the electrode positions and the wiring to apply AC power only to one electrode, and utilizes an insulating member and a shelf-shaped electrode unit like the electrode unit 50c shown in Fig. 7. Further, the electrode unit may be arranged at a fixed dstance from at least a pair of symmetric lateral faces.

[71] The door sensor 60 stops the operation of the power generator 40 as the door (120 in Fig. 7) opening/closing the storage space is open. To this end, it may inform the Micom 90 that the door 120 is opened to let the Micom 90 stop the operation of the power generator 40, or it may cut the power being supplied to the power generator 40, or it may use a switch controlling power supply(not shown) dependng on an opened/ closed state of the door to intercept the power being supplied to the power generator 40.

[72] The input unit 70 is used by a user not only to set temperature for freezing and refrigeration control in general and selecting an ice or water dspenser, but also to give a control command to perform a supercooling mode on a storage space or stored item(s). Moreover, the user can input information about a stored item, e.g., kind or amount of a stored item, through the input unit 70. The input unit 70 may be a barcode scanner or an RFID reader, and provide the information on a stored item from readng to the Micom 90. Further, the input unit 70 allows the user to input or select a desired supercooling temperature (temperature to maintain a supercooled state) for a storage space or a stored item.

[73] The dsplay unit 80 basically shows freezing and refrigeration temperatures, and which dspenser (water or ice dspenser) is being served. Also, it can also show estimated time to reach the onset of a supercooled state, or whether a supercooling operation is ON or cancelled.

[74] The Micom 90 is involved in the refrigeration and freeze control in general, and controls a supercooling mode accordng to the present invention to be executed. [75] When a storage space or a stored item is maintained in a supercooled state, the

Micom 90 stores information on relations among an amount of energy to be supplied to the storage space or to a stored item, an amount of energy to be taken away and cooling temperatures. As such, the Micom 90 can control over the setup and application of a proper amount of energy based on a target supercooling temperature, the calculation of an amount of energy, the calculation of a supercooling temperature according to a given energy, and so forth. Energy in a variety of forms can be used here. In this invention, an electric field energy is used. Since stored items are most likely to contain moisture to a great content, the Micom 90 calculates energy Ql) to take by using specific heat of water, obtaining mass from the load detector 20, and operating temperature information with the load detector 20. In case of applying an electric field energy for example, the Micom 90 calculates the energy to be supplied based on a function of voltage, current and frequency. These calculation processes are well known to those skilled in the art which the present invention pertains.

[76] The Micom 90 acquires information on the situation of a storage space of a stored item from the input unit 70 or the load detector 20, and generates an AC voltage having the magnitude and frequency corresponding to the acquired information or the degree of load, thereby being in charge of carrying out the artificial intelligence-based non-freezing mode.

[77] To carry out a supercooling mode, the Micom 90 can set or vary a temperature for the supercooling mode to be operated. The temperature setup or variation is done by the Micom 90 in use of a relation between energy quantities Ql and Q2 and a supercooling temperature (to be described). To this end, the Micom 90 controls the power generator 40 to adjust an energy quantity Q2 corresponding to an electric field induced around the electrode unit 50. In detail, the energy quantity adjustment is accomplished by controlling the magnitude and frequency of a given voltage £>r current), and the correlation among voltage, current and frequency yields an amount of energy. Since these energy calculation processes are obvious to those skilled in the art which the present invention pertains, they will not be explained.

[78] The Micom 90 also controls the operation of a non-freezing actuator consisting of the power generator 40 and the electrode unit 50. In so doing, it performs an efficient control like a sleep mode to maintain a non-freezing mode while reducing power consumption of the supercooling apparatus 100.

[79]

[80] The present invention has been described in detail with reference to the em- bodments and the attached drawings. However, the scope of the present invention is not limited to the embodments and the drawings, but defined by the appended claims.

Claims

[I] A supercooling apparatus comprising: an insulating member having a storage space formed inside to store an item; a refrigeration cycle for cooling the storage space; and an electrode unit installed inside the storage space. [2] The supercooling apparatus of claim 1, wherein the electrode unit is a plane with one side mounted at a lateral face of the insulating member. [3] The supercooling apparatus of claim 1 or claim 2, wherein the electrode unit is separated at a fixed dstance from at least a pair of symmetric lateral faces of the insulating member. [4] The supercooling apparatus of claim 3, further comprising: a support for supporting the electrode unit. [5] The supercooling apparatus of claim 1 or claim 2, fiirther comprising: a power generator for generating a high voltage; and a power transfer line for applying the voltage to the electrode unit. [6] The supercooling apparatus of claim 5, wherein a plurality of power transfer lines are connected to different nodes of the planar electrode unit. [7] The supercooling apparatus of claim 1 , wherein the electrode unit is removable from a storage. [8] A supercooling apparatus comprising: a storage for storing an item inside; a refrigeration cycle for cooling the storage; and an electrode unit mounted in the storage, for generating an electric field in at least two directions. [9] The supercooling apparatus of claim 8, wherein inner faces of the storage include an insulating member. [10] The supercooling apparatus of claim 8, wherein the electrode unit is mounted inside the storage.

[I I] The supercooling apparatus of claim 10, wherein the electrode unit is separated at a fixed dstance from at least a pair of symmetric lateral faces of the insulating member.

[12] The supercooling apparatus of claim 8, wherein the electrode unit is removable from a storage.