WO2008004770A1

WO2008004770A1 - Apparatus for supercooling and the method for defrosting an electrode of the same

Info

Publication number: WO2008004770A1
Application number: PCT/KR2007/002720
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
Current assignee: LG Electronics Inc
Priority date: 2006-07-01
Filing date: 2007-06-05
Publication date: 2008-01-10
Anticipated expiration: 2009-01-01
Also published as: KR20080003220A; KR20080003221A; KR100857324B1; WO2008004764A3; KR100850608B1; KR100857325B1; WO2008004771A1; KR100836324B1; KR100882625B1; KR20080003215A; KR20080003217A; KR100935746B1; KR20080003214A; KR100862107B1; WO2008004765A3; KR20080003222A; KR100827883B1; WO2008004762A1; KR20080003228A; WO2008004763A1

Abstract

The present invention discloses an apparatus for supercooling including a cooling chamber (120), the cool air generated by a freezing cycle in which a refrigerant flows being introduced into the cooling chamber, an electrode (230) for applying an electric field to a predetermined space in the cooling chamber, and a defrosting device (250) for defrosting the electrode. This configuration can prevent the frost of the electrode from functioning as an interference material in the electric field and weakening the electric field. Therefore, this configuration can prevent a non-frozen state of a stored object from being released due to weakening of the electric field. Furthermore, this configuration can prevent the frost from functioning as a freezing core and sharply freezing the stored object.

Description

APPARATUS FOR SUPERCOOLING AND THE METHOD FOR DEFROSTING AN ELECTRODE OF THE SAME

Technical Field

[1] The present invention relates to an apparatus for supercooling with a non-freezing chamber for storing food in a supercooled state, and more particularly, to an apparatus for supercooling with a defrosting device for defrosting an electrode for applying electric field energy to a non-freezing chamber. Background Art

[2] Supercooling means that liquid is not transited into solid but maintained in a high temperature phase, namely, in a liquid phase below a phase transition temperature to solid. One example of the supercooling is water drops supercooled in a natural state. In a general refrigerator, water or beverages happen to be supercooled, instead of being frozen. Examples of applying the supercooling principle to a refrigerator are a freezing method disclosed under Japanese Patent Laid-Open Gazette S59-151834 and a freezing method and a refrigerator disclosed under Japanese Patent Laid-Open Gazette 2001-086967. The above examples teach a technique of maintaining a stored object in a supercooled state below a phase transition temperature, by applying an electric field or a magnetic field to the stored object in the refrigerator. Meanwhile, an electrostatic field processing method disclosed under International Publication WO/98/41115 siggests various types of electrode structures that can be used to supercool and thaw a stored object.

[3] Rg. 1 illustrates one example of a refrigerator with a special storage chamber disclosed in Korean Patent Laid-Open Gazette 2003-0038999. A main body 10 of the refrigerator includes a freezing chamber 20, a refrigerating chamber 30, a special storage chamber 40 formed at the lower portion of the refrigerating chamber 30, and a freezing chamber door 21 and a refrigerating chamber door 31 hinge-coupled to the main body 10, respectively, for opening and closing the freezing chamber 20 and the refrigerating chamber 30.

[4] The special storage chamber 40 is a space for storing an easily-decayable object, such as fish and meat. If the fish or meat is stored in the freezing chamber 20, it takes a long time to thaw the frozen object for cooking. The special storage chamber 40 is intended to solve such a problem.

[5] The special storage chamber provided at the conventional refrigerator maintains a temperature lower than the refrigerating chamber and higher than the freeing chamber. Therefore, the special storage chamber is inappropriate to keep fish and meat for an extended period of time. When the user wants to keep the fish or meat over a few tens of hours, he/she still has to store the fish or meat in the freeing chamber and thaw it for cooking.

[6] Accordingly, research and development have been made to obtain an apparatus for supercooling with a non-freezing chamber for keeping a stored object below a phase transition temperature of liquid without freeing the stored object. An electrode applies an electric field to the non-freezing chamber, for preventing phase transition of liquid. Thus, the non-freezing chamber can keep the stored object for an extended period of time without freezing the stored object. The non-freezing chamber is maintained at a low temperature in use and has high relative humidity due to moisture contained in the stored object so that the electrode may be frosted. The frost functions as an interference material disturbing the electric field between the electrodes, to reduce energy efficiency. In addition, the frost may become a freezing core of liquid in the non-freezing chamber, which causes freezing of the stored object. If the electrode is irregularly frosted, the electric field applied into the non-freezing chamber becomes irregular in the non-freezing chamber. Disclosure of Invention Technical Problem

[7] An object of the present invention is to provide an apparatus for supercooling with a defrosting device for defrosting an electrode for applying an electric field to a predetermined space in a cooling chamber.

[8] Another object of the present invention is to provide an apparatus for supercooling with a non-freezing chamber for storing an object in a supercooled state in a cooling chamber.

[9] Yet another object of the present invention is to provide an apparatus for supercooling which can cool a non-freezing chamber, maintaining non-freezing stability of the non-freezing chamber.

[10] Yet another object of the present invention is to provide an apparatus for supercooling which can embody various placements of a refrigerating chamber, a freezing chamber and a non-freezing chamber. Technical Solution

[11] In order to achieve the above-described objects of the invention, there is provided an apparatus for supercooling, including: a cooling chamber, the cool air generated by a freezing cycle in which a refrigerant flows being introduced into the cooling chamber; an electrode for applying an electric field to a predetermined space in the cooling chamber; and a defrosting device for defrosting the electrode. This configuration can prevent the frost of the electrode from functioning as an interference material in the electric field and weakening the electric field. Therefore, this configuration can prevent a non-frozen state of a stored object from being released due to weakening of the electric field. Furthermore, this configuration can prevent the frost from fiinctioning as a freezing core and sharply freezing the stored object.

[12] In another aspect of the present invention, the apparatus for supercooling further includes a non-freezing chamber positioned in the cooling chamber, for storing an object in a supercooled state, wherein the electrode applies the electric field to the non- freezing chamber. In this configuration, the stored object can be stored in the supercooled state.

[13] In yet another aspect of the present invention, the apparatus for supercooling further includes an outer casing for defining the non-freezing chamber, wherein the electrode is positioned on the inner face of the outer casing. In this configuration, the non- freezing chamber can be separated from the other space in the cooling chamber, and the electric field can be applied merely into the non-freezing chamber.

[14] In yet another aspect of the present invention, the defrosting device is positioned between the electrode and the outer casing. This configuration can defrost the electrode, less affecting the inside of the non-freezing chamber and the stored object positioned in the non-freezing chamber.

[15] In yet another aspect of the present invention, the apparatus for supercooling further includes a control unit for controlling the operation of the defrosting device. In this configuration, the control unit can decide whether or not to operate the defrosting device, and operate the defrosting device in an appropriate time.

[16] In yet another aspect of the present invention, the apparatus for supercooling further includes a sensor for measuring the intensity of the electric field applied by the electrode, and transmitting the measured value to the control unit. In this configuration, the control unit can decide whether or not to operate the defrosting device according to the intensity of the electric field.

[17] In yet another aspect of the present invention, the apparatus for supercooling further includes a drain hole for draining defrost water. This configuration can prevent the defrost water from remaining in the apparatus for supercooling and generating the frost on the electrode again.

[18] In yet another aspect of the present invention, the cooling chamber includes a freezing chamber and a refrigerating chamber placed in parallel at the left and right sides, and the non-freezing chamber is provided at the refrigerating chamber.

[19] In yet another aspect of the present invention, the cool air circulated in the freezing chamber is supplied to the non-freezing chamber positioned in the refrigerating chamber.

[20] In yet another aspect of the present invention, the cool air generated in the refrigerating chamber is supplied to the non-freezing chamber.

[21] In yet another aspect of the present invention, the freezing cycle includes an evaporator positioned on the rear face of the freezing chamber, part of the evaporator being extended to the non-freezing chamber to cool the non-freezing chamber.

[22] In yet another aspect of the present invention, the freezing cycle includes an evaporator positioned on the rear face of the refrigerating chamber, part of the evaporator being extended to the non-freezing chamber to cool the non-freezing chamber.

[23] In yet another aspect of the present invention, the apparatus for supercooling includes a refrigerating chamber and a freezing chamber placed in parallel at the left and right sides, wherein the non-freezing chamber is insulated by an insulation material and positioned in the freezing chamber.

[24] In yet another aspect of the present invention, the apparatus for supercooling includes a refrigerating chamber and a freezing chamber placed in parallel at the left and right sides, wherein the non-freezing chamber is positioned in a space separated from the refrigerating chamber and the freezing chamber.

[25] In yet another aspect of the present invention, the apparatus for supercooling includes a freezing chamber positioned at the upper portion and a refrigerating chamber positioned at the lower portion of the cooling chamber, wherein the non- freezing chamber is provided at the refrigerating chamber.

[26] In yet another aspect of the present invention, the cool air circulated in the freezing chamber is supplied to the non-freezing chamber positioned in the refrigerating chamber.

[27] In yet another aspect of the present invention, the cool air generated in the refrigerating chamber is supplied to the non-freezing chamber.

[28] In yet another aspect of the present invention, the freezing cycle includes an evaporator positioned on the rear face of the freezing chamber, part of the evaporator being extended to the non-freezing chamber to cool the non-freezing chamber.

[29] In yet another aspect of the present invention, the freezing cycle includes an evaporator positioned on the rear face of the refrigerating chamber, part of the evaporator being extended to the non-freezing chamber to cool the non-freezing chamber.

[30] In yet another aspect of the present invention, the apparatus for supercooling includes a freezing chamber positioned at the upper portion and a refrigerating chamber positioned at the lower portion of the cooling chamber, wherein the non- freezing chamber is insulated by an insulation material and positioned in the freezing chamber.

[31] In yet another aspect of the present invention, the apparatus for supercooling includes a freezing chamber positioned at the upper portion and a refrigerating chamber positioned at the lower portion of the cooling chamber, wherein the non- freezing chamber is positioned in a space separated from the refrigerating chamber and the freezing chamber.

[32] In yet another aspect of the present invention, the apparatus for supercooling includes a freezing chamber positioned at the lower portion and a refrigerating chamber positioned at the upper portion of the cooling chamber, wherein the non- freezing chamber is provided at the refrigerating chamber.

[33] In yet another aspect of the present invention, the cool air circulated in the freezing chamber is supplied to the non-freezing chamber positioned in the refrigerating chamber.

[34] In yet another aspect of the present invention, the cool air generated in the refrigerating chamber is supplied to the non-freezing chamber.

[35] In yet another aspect of the present invention, the freezing cycle includes an evaporator positioned on the rear face of the freezing chamber, part of the evaporator being extended to the non-freezing chamber to cool the non-freezing chamber.

[36] In yet another aspect of the present invention, the freezing cycle includes an evaporator positioned on the rear face of the refrigerating chamber, part of the evaporator being extended to the non-freezing chamber to cool the non-freezing chamber.

[37] In yet another aspect of the present invention, the apparatus for supercooling includes a freezing chamber positioned at the lower portion and a refrigerating chamber positioned at the upper portion of the cooling chamber, wherein the non- freezing chamber is insulated by an insulation material and positioned in the freezing chamber.

[38] In yet another aspect of the present invention, the apparatus for supercooling includes a freeing chamber positioned at the lower portion and a refrigerating chamber positioned at the upper portion of the cooling chamber, wherein the non- freezing chamber is positioned in a space separated from the refrigerating chamber and the freezing chamber.

[39] In addition, there is provided a method for defrosting an electrode of an apparatus for supercooling, including: a first step for deciding whether or not to defrost the electrode; and a second step for defrosting the electrode. According to this method, the electrode for applying an electric field to a predetermined region of a cooling chamber can be defrosted to prevent a non-frozen state from being released due to weakening of the electric field.

[40] In another aspect of the present invention, the first step includes a process for measuring an intensity of an electric field. According to this method, the change of the intensity of the electric field applied by the electrode can be sensed.

[41] In yet another aspect of the present invention, the first step includes a process for judging whether the electrode has been frosted according to the measured intensity of the electric field. According to this method, the defrosting step can be conducted in an appropriate time, namely, in frosting, for improving efficiency of the apparatus for supercooling.

[42] In yet another aspect of the present invention, the first step decides whether or not to defrost the electrode according to the operation time of the apparatus for supercooling. According to this method, even if the apparatus for supercooling does not include a sensor, the electrode can be defrosted at intervals of a predetermined time. Advantageous Effects

[43] In accordance with the present invention, the apparatus for supercooling can prevent the non-frozen state of the object stored in the electric field applied region from being released due to weakening of the electric field applied by the electrode, by including the defrosting device for defrosting the electrode.

[44] In accordance with the present invention, the apparatus for supercooling can prevent the frost from functioning as the freezing core and freezing the stored object, by defrosting the electrode.

[45] In accordance with the present invention, the method for defrosting the apparatus for supercooling can stably maintain the non-frozen state of the object stored in the apparatus for supercooling, by defrosting the electrode when the electrode frosted. [46] In accordance with the present invention, the apparatus for supercooling includes the refrigerating chamber, the freezing chamber and the non-freezing chamber so that the user can select an appropriate keeping space of food according to the kind and keeping period of the food.

[47] In accordance with the present invention, the apparatus for supercooling does not directly spray the cool air to the non-freezing chamber, and thus does not generate a stimulus by spraying of the cool air, which results in excellent non-freezing stability.

[48] In accordance with the present invention, the apparatus for supercooling contacts the refrigerant tube extended from the evaporator with the non-freezing chamber to directly exchange heat with the atmosphere of the non-freezing chamber, and thus does not generate a stimulus by gas flow, which results in excellent non-freezing stability. Brief Description of the Drawings

[49] The present invention will become better understood with reference to the accompanying drawings which are given only by way of illustration and thus are not limitative of the present invention, wherein:

[50] Hg. 1 illustrates one example of a conventional refrigerator with a special storage chamber;

[51] Hg. 2 illustrates a non-freezing chamber in accordance with a first embodiment of the present invention;

[52] Hg. 3 illustrates a non-freezing chamber in accordance with a second embodiment of the present invention;

[53] Rg. 4 illustrates a non-freezing chamber in accordance with a third embodiment of the present invention;

[54] Rg. 5 illustrates an outer casing in accordance with a fourth embodiment of the present invention;

[55] Rg. 6 illustrates a top mount type refrigerator applied with a non-freezing chamber in accordance with a first embodiment of the present invention;

[56] Rg. 7 illustrates a top mount type refrigerator applied with a non-freezing chamber in accordance with a second embodiment of the present invention;

[57] Rg. 8 illustrates a side by side type refrigerator applied with a non-freezing chamber in accordance with a first embodiment of the present invention;

[58] Rg. 9 illustrates the side by side type refrigerator applied with the non-freezing chamber in accordance with the first embodiment of the present invention;

[59] Rg. 10 illustrates a side by side type refrigerator applied with a non-freezing chamber in accordance with a second embodiment of the present invention; [60] Hg. 11 illustrates a bottom freezer type refrigerator with a non-freezing chamber in accordance with a first embodiment of the present invention;

[61] Fig. 12 illustrates a bottom freezer type refrigerator with a non-freezing chamber in accordance with a fourth embodiment of the present invention; and

[62] Figs. 13 to 15 are flowcharts showing sequential steps of methods for defrosting an electrode of an apparatus for supercooling in accordance with first and second embodiments of the present invention. Mode for the Invention

[63] An apparatus for supercooling and a method for defrosting an electrode of the same in accordance with preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[64] Rg. 2 illustrates a non-freezing chamber in accordance with a first embodiment of the present invention. An apparatus for supercooling with a non-freezing chamber 200 includes an inner casing 210 for defining the non-freezing chamber 200, an outer casing 220 for surrounding the inner casing 210, an electrode 230 positioned on the inner face of the outer casing 220, a cool air inflow hole 242 and a cool air outflow hole 244 for letting the cool air in and out, a defrosting device 250 positioned between the electrode 230 and the outer casing 220, for defrosting the electrode 230, a drain hole 260 formed at the outer casing 220, for discharging defrost water, and a sensor 270 for sensing the state of the non-freezing chamber 200.

[65] The inner casing 210 is formed in a drawer shape and housed in the outer casing

220. The outer casing 220 is formed in a box shape with a front face opened or openable. Therefore, the inner casing 210 can be taken out in the forward direction through the front face of the outer casing 220. The cool air inflow hole 242 and the cool air outflow hole 244 for letting the cool air in and out are formed at the outer casing 220. The cool air is introduced into the non-freezing chamber 200 through the cool air inflow hole 242 so that the non-freezing chamber 200 can maintain a low temperature. The cool air inflow hole 242 and the cool air outflow hole 244 may be formed at any portions of the outer casing 220. The portion for supplying the cool air to the non-freezing chamber 200 and the portion for discharging the cool air from the non-freezing chamber 200 are changed according to the relation between the non- freezing chamber 200 and the other components of the apparatus for supercooling. Accordingly, the positions of the cool air inflow hole 242 and the cool air outflow hole 244 are changed. A damper (not shown) can be installed in the cool air inflow hole 242 so as to control the inflow of the cool air to the non-freezing chamber 200. According to the temperature measured by the sensor 270, when the temperature inside the non- freezing chamber 200 rises, a control unit (not shown) opens the damper (not shown) to introduce the cool air into the non-freezing chamber 200. When the temperature inside the non-freezing chamber 200 seriously lowers, the control unit (not shown) closes the damper (not shown) to prevent the inflow of the cool air to the non-freezing chamber 200. A blowing fan (not shown) can be provided at a passage to smoothly introduce the cool air into the non-freezing chamber 200 through the cool air inflow hole 242. According to the temperature information measured by the sensor 270, when the temperature is high, the control unit (not shown) can operate the blowing fan (not shown) to increase the inflow amount of the cool air, and when the temperature is low, the control unit (not shown) can stop the operation of the blowing fan (not shown). The damper (not shown) and the blowing fan (not shown) can be provided individually or together.

[66] The electrode 230 for applying the electric field to the non-freezing chamber 200 is positioned on the inner face of the outer casing 220. As hydrogen coupling of water is disturbed by energy of the electric field, water is not frozen but maintained in a liquid phase below a phase transition temperature, namely, below a water freezing point. Normally, the electrode 230 is provided in a pair to apply the electric field therebetween. Therefore, the pair of electrodes 230 are positioned on the facing inner faces of the outer casing 220. The facing inner faces on which the electrodes 230 are positioned may be the top and bottom faces or both side faces of the outer casing 220. In this configαration, while the non-freezing chamber 200 is maintained below the phase transition temperature of water by using the cool air, the phase transition of water is disturbed by applying the electric field to the non-freezing chamber 200 by using the electrodes 230. As a result, the stored object can be kept below the phase transition temperature without being frozen.

[67] As the cool air is introduced into the outer casing 220, the electrodes 230 and the inner faces of the outer casing 220 may be frosted. In this case, the intensity of the electric field applied by the electrodes 230 is weakened to reduce energy efficiency. When the inner faces of the outer casing 220 are frosted, it is difficult to take out the inner casing 210. If the frost is dropped into the inner casing 210, namely, into the non-freezing chamber 200, it may junction as a freezing core and cause freezing of the stored object. It is thus necessary to conduct the defrosting. The apparatus for supercooling includes the defrosting device 250 for defrosting the electrode 230. The representative example of the defrosting device 250 is a heater. After power supply to the electrode 230 is cut off, the heater generates heat to defrost the electrode 230. When the heater generates heat, the frost is turned into defrost water. If the defrost water is not discharged, it may be frozen or generate the frost again, and is not good for the health. It is thus preferable to directly discharge the defrost water. Accordingly, the drain hole 260 is formed at the lower portion of the outer casing 220. The drain hole 260 is connected to a drain passage (not shown), for externally discharging the defrost water.

[68] The sensor 270 is installed to sense the state of the non-freezing chamber 200.

Considering that the inner casing 210 is a moving member, it is not easy to install a circuit therein. It is thus preferable to install the sensor 270 on the top face among the inner faces of the outer casing 220. If the sensor 270 is installed on the side face or the bottom face among the inner faces of the outer casing 220, the sensor 270 is hidden by the inner casing 210, and thus cannot substantially sense the state of the non-freezing chamber 200. The sensor 270 senses the temperature inside the non-freezing chamber 200 and the intensity of the electric field applied to the non-freezing chamber 200. In order for the conditions of the non-freezing chamber 200 to satisfy the supercooling condition, the sensor 270 continuously senses the temperature and the intensity of the electric field and transmits the sensed values to the control unit (not shown), and the control unit (not shown) controls the inflow amount and temperature of the cool air and the voltage applied to the electrodes 230 according to the sensed values. The control unit (not shown) discriminates whether or not to defrost the electrode 230 and operates the defrosting device 250.

[69] The outer casing 220 may be made of an insulation material or may include an insulation layer. Particularly, when the non-freezing chamber 200 is formed in a cooling chamber discussed later among supercooling chambers, the ambient temperature is higher than the temperature inside the non-freezing chamber 200. It is thus usefiαl to provide the insulation function to the outer casing 220.

[70] Fig. 3 illustrates a non-freezing chamber in accordance with a second embodiment of the present invention. As identical to the apparatus for supercooling according to the first embodiment of the present invention, an apparatus for supercooling with a non- freezing chamber 200 includes an inner casing 210 for defining the non-freezing chamber 200, an outer casing 220 for surrounding the inner casing 210, an electrode 230 positioned on the inner face of the outer casing 220, a defrosting device 250 for defrosting the electrode 230, a drain hole 260 formed at the outer casing 220, for discharging defrost water, and a sensor 270 for sensing the state of the non-freezing chamber 200. To maintain the non-freezing chamber 200 at a low temperature, the apparatus for supercooling according to the first embodiment includes the cool air inflow hole (242 in Rg. 2) and the cool air outflow hole (244 in Fig. 2), but the apparatus for supercooling according to the second embodiment includes a refrigerant tube 246 extended from part of an evaporator (not shown), for letting a refrigerant flow therein. The refrigerant tube 246 in which the low temperature refrigerant flows has a low temperature. Particularly, if the refrigerant tube 246 is exposed to the non-freezing chamber 200, the refrigerant tube 246 is easily frosted. As described above, when the non-freezing chamber 200 is frosted, the non-frozen supercooled state of the whole non-freezing chamber 200 is easily released. Therefore, the refrigerant tube 246 is preferably positioned on the outer face of the outer casing 220. In order to reduce the length of the refrigerant tube 246 extended from the evaporator (not shown), the refrigerant tube 246 is preferably formed on the rear face among the outer faces of the outer casing 220. However, the refrigerant tube 246 may be installed at any one of the outer faces of the outer casing 220. A valve (not shown) for controlling the inflow of the refrigerant to the refrigerant tube 246 can be installed at the refrigerant tube 246. According to the temperature information of the non-freezing chamber 200 measured by the sensor 270, when the temperature inside the non-freezing chamber 200 is high, the valve (not shown) allows the inflow of the refrigerant to the refrigerant tube 246, and when the temperature inside the non-freezing chamber 200 is low, the valve (not shown) prevents the inflow of the refrigerant to the refrigerant tube 246. Especially, when the non-freezing chamber 200 is cooled by the refrigerant tube 246, a strong flow which may become a stimulus of freezing liquid is not generated in the non- freezing chamber 200, to thereby improve non-freezing stability.

[71] Fig. 4 illustrates a non-freezing chamber in accordance with a third embodiment of the present invention. As identical to the apparatuses for supercooling according to the first and second embodiments of the present invention, an apparatus for supercooling with a non-freezing chamber 200 includes an inner casing 210 for defining the non- freezing chamber 200, an outer casing 220 for surrounding the inner casing 210, an electrode 230 positioned on the inner face of the outer casing 220, a defrosting device 250 for defrosting the electrode 230, a drain hole 260 formed at the outer casing 220, for discharging defrost water, and a sensor 270 for sensing the state of the non-freezing chamber 200. So as to maintain the non-freezing chamber 200 at a low temperature, the apparatus for supercooling may include the cool air inflow hole (242 in Fig. 2) and the cool air outflow hole (244 in Fig. 2) as in the first embodiment, or include the re- frigerant tube (246 in Fig. 3) extended from part of the evaporator (not shown), for letting the refrigerant flow therein as in the second embodiment.

[72] In the non-freezing chamber 200 of the third embodiment, the front face of the inner casing 210 is made of a see-thrcugh material. As the front face of the outer casing 220 is open, if the front face of the inner casing 210 is made of a see-throtgh material, the inside of the non-freezing chamber 200 can be observed from the front faces of the inner casing 210 and the outer casing 220 without taking out the inner casing 210. The electrodes 230 can be formed on the top and bottom faces or both side faces among the inner faces of the outer casing 220. As another example, the top face of the outer casing 220 can also be made of a see-through material. In this case, as the top face of the inner casing 210 is open, the object stored in the non-freezing chamber 200 can be observed from the upper portions of the inner casing 210 and the outer casing 220. Here, if the electrodes 230 are positioned on the top and bottom faces among the inner faces of the outer casing 220, the non-freezing chamber 200 is bidden by the electrode 230 so that the stored object cannot be easily observed. Therefore, the electrodes 230 are preferably positioned on the side faces among the inner faces of the outer casing 220. The side faces and the bottom face of the inner casing 210 and the side faces and the bottom face of the outer casing 220 may be made of a see-through material or a non-see-through material. Considering that it is easy to integrally manufacture the inner casing 210 and the outer casing 220, respectively, the whole faces of the inner casing 210 and the whole faces of the outer casing 220 can be made of a see-through material.

[73] The side faces and the rear face of the inner casing 210 can include reflection faces

212. In this configuration, the rear or side state of the stored object can be observed from the front faces of the inner casing 210 and the cuter casing 220, namely, from the front face of the non-freezing chamber 200 without taking out the inner casing 210. The reflection face 212 may be provided at any one of both side faces and the rear face of the inner casing 210. However, in order to clearly check the state of the stored object in the non-freezing chamber 200, the reflection faces 212 are preferably provided at both side faces and the rear face of the inner casing 210. Any kind of member that can be adhered to the inner casing 210 to show the state of the stored object by reflecting light, such as a reflection film, a mirror and a metal coating can be used as the reflection face 212.

[74] Fig. 5 illustrates an outer casing in accordance with a fourth embodiment of the present invention. In an apparatus for supercooling with a non-freezing chamber 200, a door 220D for opening and closing an inside space of an outer casing 220 is formed on the front face of the outer casing 220. The door 220D is hinge-coupled to one side of the outer casing 220. As the outer casing 220 includes the door 220D, it is much easier to maintain the non-freezing chamber 200 at a low temperature. For example, when the non-freezing chamber 200 is provided at a refrigerating chamber discussed later, the atmosphere of the refrigerating chamber may be introduced through the gap between the outer casing 220 and an inner casing (210 in Fig. 2), to raise the temperature of the non-freezing chamber 200. Therefore, the non-freezing chamber 200 needs more cool air or refrigerant, which lowers energy efficiency. Such loss can be reduced by forming the door 220D at the outer casing 220.

[75] Fig. 6 illustrates a top mount type refrigerator applied with a non-freezing chamber in accordance with a first embodiment of the present invention. A refrigerator 100 includes a freezing chamber 110 and a refrigerating chamber 120 as cooling chambers. A non-freezing chamber for storing an object for an extended period of time without freezing the object is positioned in the refrigerating chamber 120. In addition, the refrigerator 100 includes a freezing cycle to preserve the stored object at a low temperature. The freezing cycle includes a condenser (not shown), an evaporator 130, a compressor 140 and an expansion valve (not shown). The atmosphere of the freezing chamber 110 exchanges heat with the refrigerant passing through the evaporator 130, to generate the cool air. The cool air is naturally convected or forcibly convected by a blower 150, and introduced into the freezing chamber 110, for maintaining the freezing chamber 110 at a low temperature. Some of the cool air introduced into the freezing chamber 110 is introduced into the refrigerating chamber 120 through a duct 160.

[76] Here, the duct 160 introduces the cool air into the non-freezing chamber 200. The cool air introduced into the non-freezing chamber 200 is discharged to the refrigerating chamber 120 to cool the whole refrigerator 100. In the non-freezing chamber 200, a cool air inflow hole (242 in Fig. 2) and the duct 160 are connected to each other so that the cool air can flow therethrough. A cool air outflow hole (246 in Fig. 2) is formed at the side of the refrigerating chamber 120, particularly, at the lower portion of the non- freezing chamber 200. Therefore, after cooling the non-freezing chamber 200, the cool air can be discharged to the refrigerating chamber 120.

[77] Fig. 7 illustrates a top mount type refrigerator applied with a non-freezing chamber in accordance with a second embodiment of the present invention. Identically to the top mount type refrigerator according to the first embodiment of the present invention, a non-freezing chamber 200 is formed in a refrigerating chamber 120. However, the cool air is not introduced through a duct 160. Instead, a refrigerant tube 246 extended from part of an evaporator 130 is positioned at the back of the non-freezing chamber 200. The refrigerant tube 246 cools the non-freezing chamber 200 by directly contacting a rear face of an outer casing (220 in Fig. 3) and exchanging heat with the atmosphere of the non-freezing chamber 200.

[78] Referring to Figs. 6 and 7, a refrigerator wherein a non-freezing chamber 200 is positioned in a freezing chamber 110 and indirectly cooled as in the first embodiment can be configured as a top mount type refrigerator applied with a non-freezing chamber according to a third embodiment of the present invention. A refrigerator wherein a non-freezing chamber 200 is positioned in a freezing chamber 110 and cooled by a refrigerant tube 246 extended from part of an evaporator 130 as in the second embodiment can be configured as a top mount type refrigerator applied with a non-freezing chamber according to a fourth embodiment of the present invention. In addition, refrigerators including an evaporator for exchanging heat with an atmosphere of cooling a freezing chamber 110 and an evaporator for exchanging heat with an atmosphere of cooling a refrigerating chamber 120, respectively, wherein a non- freezing chamber 200 is positioned in the freezing chamber 110 and indirectly and directly cooled, respectively, can be configured as top mount type refrigerators applied with non-freezing chambers according to fifth and sixth embodiments of the present invention. Furthermore, refrigerators including an evaporator for exchanging heat with an atmosphere of cooling a freezing chamber 110 and an evaporator for exchanging heat with an atmosphere of cooling a refrigerating chamber 120, respectively, wherein a non-freezing chamber 200 is positioned in the refrigerating chamber 120 and indirectly and directly cooled, respectively, can be configured as top mount type refrigerators applied with non-freezing chambers according to seventh and eighth embodiments of the present invention.

[79] Figs. 8 and 9 illustrate a side by side type refrigerator applied with a non-freezing chamber in accordance with a first embodiment of the present invention. A freezing chamber 110 and a refrigerating chamber 120 are longitudinally placed at the left and right sides, respectively. An evaporator 130 is positioned on the rear face of the freezing chamber 110, for exchanging heat with the atmosphere and generating the cool air. The cool air is introduced into the freezing chamber 110, for maintaining the refrigerator at a low temperature. The cool air heat-exchanged with the evaporator 130 is introduced into a non-freezing chamber 200 through a duct 160 and a cool air inflow hole 242. After cooling the non-freezing chamber 200, the cool air is discharged to the refrigerating chamber 120 through a cool air outflow hole 244 and cools the refrigerating chamber 120. Alternatively, after cooling the non-freezing chamber 200, the cool air may be discharged to the freezing chamber 110, instead of the refrigerating chamber 120.

[80] Rg. 10 illustrates a side by side type refrigerator applied with a non-freezing chamber in accordance with a second embodiment of the present invention. Part of an evaporator 130 is extended to a refrigerating chamber 120 to contact a rear face of an outer casing 220, to thereby forming a refrigerant tube 246. The refrigerant tube 246 contacting the rear face among the outer faces of the outer casing 220 directly exchanges heat with an atmosphere of a non-freezing chamber 200. Accordingly, the non-freezing chamber 200 can be maintained at a low temperature.

[81] A refrigerator wherein a non-freezing chamber 200 is positioned in a refrigerating chamber 120, evaporators 130 are formed in a freezing chamber 110 and the refrigerating chamber 120, respectively, and the cool air of the refrigerating chamber 120 is introduced into the non-freezing chamber 200 can be configured as a side by side type refrigerator applied with a non-freezing chamber according to a third embodiment of the present invention. A refrigerator wherein a non-freezing chamber 200 is positioned in a refrigerating chamber 120, evaporators 130 are formed in a freezing chamber 110 and the refrigerating chamber 120, respectively, and the atmosphere of the non-freezing chamber 200 directly exchanges heat with the evaporator 130 positioned at the side of the refrigerating chamber 120 or a refrigerant tube 246 extended from the evaporator 130 can be configured as a side by side type refrigerator applied with a non-freezing chamber according to a fourth embodiment of the present invention. A refrigerator wherein a non-freezing chamber 200 is positioned in a freezing chamber 110 and the cool air of the freezing chamber 110 is introduced into the non-freezing chamber 200 can be configured as a side by side type refrigerator applied with a non-freezing chamber according to a fifth embodiment of the present invention. A refrigerator wherein a non-freezing chamber 200 is positioned in a freezing chamber 110 and directly exchanges heat with an evaporator 130 positioned in the freezing chamber 110 or a refrigerant tube 246 extended from the evaporator 130 can be configured as a side by side type refrigerator applied with a non-freezing chamber according to a sixth embodiment of the present invention.

[82] Hg. 11 illustrates a bottom freezer type refrigerator with a non-freezing chamber in accordance with a first embodiment of the present invention. A refrigerating chamber 120 is placed at the upper portion and a freezing chamber 110 is placed at the lower portion. An evaporator 130 is positioned at the lower portion of the refrigerator 100, namely, at the rear face side of the freezing chamber 110. A non-freezing chamber 200 is placed in the refrigerating chamber 120. The cool air is introduced from the freezing chamber 110 to the non-freezing chamber 200 through a cool air inflow hole 242 formed at a lower portion of an outer casing 220. The cool air introduced into the non- freezing chamber 200 cools the non-freezing chamber 200, and is discharged to the refrigerating chamber 120 through a cool air outflow hole 244 formed at the upper portion of the outer casing 220. A refrigerator wherein a cool air outflow hole 244 is formed at a lower portion of an outer casing 220, for sending the cool air to a freezing chamber 110 instead of a refrigerating chamber 120 can be configured as a bottom freezer type refrigerator according to a second embodiment of the present invention. A refrigerator further including a refrigerant tube (not shown) extended from an evaporator 130 to at least part among a bottom face, side faces and a rear face of an outer casing 220, wherein an atmosphere of a non-freezing chamber 200 directly exchanges heat with a refrigerant passing through the refrigerant tube, for maintaining the non-freezing chamber 200 at a low temperature can be configured as a bottom freezer type refrigerator according to a third embodiment of the present invention. A refrigerator wherein a non-freezing chamber 200 is positioned in a freezing chamber 110 and cooled as in the first to third embodiments can also be configured.

[83] Fig. 12 illustrates a bottom freezer type refrigerator with a non-freezing chamber in accordance with a fourth embodiment of the present invention. A door of a refrigerating chamber 120 is omitted to illustrate an inside structure of a refrigerator 100 in more detail. The refrigerating chamber 120 is placed at the upper portion and a freezing chamber 110 is placed at the lower portion. Here, evaporators 130 are positioned at the side of the freezing chamber 110 and the side of the refrigerating chamber 120, respectively, for independently cooling the freezing chamber 110 and the refrigerating chamber 120. The evaporator 130 positioned at the side of the refrigerating chamber 120 exchanges heat with an atmosphere of a non-freezing chamber 200, for maintaining the non-freezing chamber 200 at a low temperature. The evaporator 130 can directly exchange heat with the non-freezing chamber 200. Alternatively, a refrigerant tube 246 extended from part of the evaporator 130 to the outside of the non-freezing chamber 200, namely, to a periphery of an outer casing 220 can exchange heat with the atmosphere of the non-freezing chamber 200.

[84] A refrigerator wherein evaporators 130 are provided at the side of a freezing chamber 110 and the side of a refrigerating chamber 120, respectively, and the cool air is introduced from the refrigerating chamber 120, for indirectly cooling a non-freezing chamber 200 can be configured as a bottom freezer type refrigerator according to a fifth embodiment of the present invention. Here, an outer casing 220 includes a cool air inflow hole (242 in Rg. 2) for introducing the cool air from the refrigerating chamber 120, and a cool air outflow hole (244 in Fig. 2) for discharging the cool air to the refrigerating chamber 120.

[85] A refrigerator wherein a non-freezing chamber 200 is positioned in a freezing chamber 110, evaporators 130 are provided at the side of the freezing chamber 110 and the side of a refrigerating chamber 120, respectively, and the non-freezing chamber 200 directly exchanges heat with the evaporator 130 positioned at the side of the freezing chamber 110 or a refrigerant tube (246 in Fig. 2) extended from the evaporator 130 can be configured as a bottom freezer type refrigerator according to a sixth embodiment of the present invention. A refrigerator wherein a non-freezing chamber 200 is positioned in a freezing chamber 110, evaporators 130 are provided at the side of the freezing chamber 110 and the side of a refrigerating chamber 120, respectively, and the cool air introduced into the freezing chamber 110 is supplied through a cool air inflow hole (242 in Fig. 2) to cool the non-freezing chamber 200, and discharged again to the freezing chamber 110 through a cool air outflow hole (244 in Fig. 2) can be configured as a bottom freezer type refrigerator according to a seventh embodiment of the present invention.

[86] In addition to the above embodiments of the present invention, the position of the non-freezing chamber can be changed according to the existence/absence and position of a display, an ice making device and a dispenser for externally supplying water in the refrigerating chamber and the freezing chamber. The position of the cool air inflow hole for introducing the cool air can be changed according to whether the cool air is introduced from the freezing chamber or the refrigerating chamber. The position of the cool air outflow hole for discharging the cool air can be changed according to the space to which the cool air is discharged after cooling the non-freezing chamber.

[87] Fig. 13 is a flowchart showing a method for defrosting an electrode of an apparatus for supercooling in accordance with a first embodiment of the present invention.

[88] A control unit (not shown) judges whether the defrosting is necessary (S 1). If the defrosting is necessary, the control unit (not shown) operates a defrosting device (250 in Hg. 2) (S2). If not, the control unit (not shown) returns to the step (Sl) for judging whether the defrosting is necessary. After operating the defrosting device (250 in Fig. 2), the control unit (not shown) returns to the step (Sl) for judging whether the defrosting is necessary. For example, if an intensity of an electric field measured by a sensor (270 in Fig. 2) positioned in a non-freezing chamber (200 in Fig. 2) exceeds an adequate range, the control unit (not shown) judges that an electrode (230 in Fig. 2) has been frosted, and operates the defrosting device (250 in Fig. 2). As another example, the control unit (not shown) can compare the operation time of the electrode (230 in Fig. 2) or the elapsed time from the previous defrosting time with a preset time. If the time is equal to or larger than the preset time, the control unit (not shown) operates the defrosting device (250 in Fig. 2). The preset time is a time in which the electrode (230 in Fig. 2) is so excessively frosted that the intensity of the electric field is changed to destroy non-freezing stability of the food stored in the non-freezing chamber (200 in Fig. 2). The preset time is computed by experiment in consideration of the size of the non-freezing chamber (200 in Fig. 2), the electrode (230 in Fig. 2) and the temperature of the cool air introduced into the non-freezing chamber (200 in Fig. 2), and input to the control unit (not shown) in advance.

[89] When the control unit (not shown) operates the defrosting device (250 in Fig. 2), it can cut off power applied to the electrode (230 in Fig. 2). That is, when the control unit (not shown) operates the defrosting device (250 in Fig. 2), the temperature inside the non-freezing chamber (200 in Fig. 2) may rise over a phase transition temperature. In this case, even if the electric field is applied to the non-freezing chamber (200 in Fig. 2), it does not create an environment for storing food in a supercooled state. Therefore, the control unit (not shown) cuts off power applied to the electrode (230 in Fig. 2), to thereby improve power efficiency.

[90] Fig. 14 is a flowchart showing a method for defrosting an electrode of an apparatus for supercooling in accordance with a second embodiment of the present invention.

[91] A step (Sl) for judging, at a control unit (not shown), whether the defrosting is necessary includes a process (Pl) for receiving information on an intensity of an electric field measured by a sensor (270 in Fig. 2), and a process (P2) for judging whether the electrode (230 in Fig. 2) has been frosted. For example, in the process (P2), the control unit (not shown) compares the intensity range of the electric field in the normal state with the intensity of the electric field measured by the sensor (270 in Fig. 2). If the intensity of the electric field measured by the sensor (270 in Fig. 2) exists outside the intensity range of the electric field in the normal state, the control unit (not shown) judges that the electrode (230 in Fig. 2) has been frosted. As the judgment result, if the control unit (not shown) judges that the electrode (230 in Fig. 2) has been frosted, the control unit (not shown) enters the step (S2) for operating the defrosting device (250 in Fig. 2), and if not, the control unit (not shown) returns to the process (Pl) for receiving the information on the intensity of the electric field measu red by the sensor (270 in Fig. 2).

[92] Here, the step (S2) for operating the defrosting device (250 in Fig. 2) and the process (Pl) for receiving the information on the intensity of the electric field measured by the sensor (270 in Fig. 2) can be conducted at the same time.

[93] Fig. 15 is a flowchart showing a method for defrosting an electrode of an apparatus for supercooling in accordance with a third embodiment of the present invention.

[94] A step (Sl) for judging, at a control unit (not shown), whether the defrosting is necessary includes a process (Pl) for computing an operation time of an electrode (230 in Fig. 2), and a process (P2) for comparing the operation time of the electrode (230 in Fig. 2) with a preset time. Here, the preset time is a time in which the electrode (230 in Fig. 2) is so excessively frosted as to affect the intensity of the electric field. The present time is input to the control unit (not shown) in advance. If the operation time of the electrode (230 in Fig. 2) is equal to or larger than the preset time, the control unit (not shown) performs a step (S2) for operating the defrosting device (250 in Fig. 2), and if the operation time of the electrode (230 in Rg. 2) is smaller than the preset time, the control unit (not shown) returns to the process (Pl) for computing the operation time of the electrode (230 in Fig. 2). The control unit (not shown) may compare the last operation time of the defrosting device (250 in Fig. 2) with the preset time, instead of the operation time of the electrode (230 in Fig. 2). According to this method, even if the apparatus for supercooling does not include a sensor, it can defrost the electrode (230 in Fig. 2) in an appropriate time.

[95]

[96] Althotgh the preferred embodiments of the present invention have been described, it is understood that the present invention should not be limited to these preferred embodiments but various changes and modifications can be made by one skilled in the art within the spirit and scope of the present invention as hereinafter claimed.

Claims

[I] An apparatus for supercooling, comprising: a cooling chamber, the cool air generated by a freezing cycle in which a refrigerant flows being introduced into the cooling chamber; an electrode for applying an electric field to a predetermined space in the cooling chamber; and a defrosting device for defrosting the electrode. [2] The apparatus for supercooling of claim 1, farther comprising a non-freezing chamber positioned in the cooling chamber, for storing an object in a non-frozen supercooled state, wherein the electrode applies the electric field to the non-freezing chamber. [3] The apparatus for supercooling of claim 2, further comprising an outer casing for defining the non-freezing chamber, wherein the electrode is positioned on the inner face of the outer casing. [4] The apparatus for supercooling of claim 3, wherein the defrosting device is positioned between the electrode and the outer casing. [5] The apparatus for supercooling of claim 1, further comprising a control unit for controlling the operation of the defrosting device. [6] The apparatus for supercooling of claim 5, further comprising a sensor for measuring the intensity of the electric field applied by the electrode, and transmitting the measured value to the control unit. [7] The apparatus for supercooling of claim 1, further comprising a drain hole for draining defrost water. [8] The apparatus for supercooling of claim 2, comprising a freezing chamber and a refrigerating chamber placed in parallel at the left and right sides, wherein the non-freezing chamber is provided at the refrigerating chamber. [9] The apparatus for supercooling of claim 8, wherein the cool air circulated in the freezing chamber is supplied to the non-freezing chamber positioned in the refrigerating chamber. [10] The apparatus for supercooling of claim 8, wherein the cool air generated in the refrigerating chamber is supplied to the non-freezing chamber.

[II] The apparatus for supercooling of claim 8, wherein the freezing cycle comprises an evaporator positioned on the rear face of the freezing chamber, part of the evaporator being extended to the non-freezing chamber to cool the non-freezing chamber.

[12] The apparatus for supercooling of claim 8, wherein the freezing cycle comprises an evaporator positioned on the rear face of the refrigerating chamber, part of the evaporator being extended to the non-freezing chamber to cool the non-freezing chamber.

[13] The apparatus for supercooling of claim 2, comprising a refrigerating chamber and a freezing chamber placed in parallel at the left and right sides, wherein the non-freezing chamber is insulated by an insulation material and positioned in the freezing chamber.

[14] The apparatus for supercooling of claim 2, comprising a refrigerating chamber and a freezing chamber placed in parallel at the left and right sides, wherein the non-freezing chamber is positioned in a space separated from the refrigerating chamber and the freezing chamber.

[15] The apparatus for supercooling of claim 2, comprising a freezing chamber positioned at the upper portion and a refrigerating chamber positioned at the lower portion of the cooling chamber, wherein the non-freezing chamber is provided at the refrigerating chamber.

[16] The apparatus for supercooling of claim 15, wherein the cool air circulated in the freezing chamber is supplied to the non-freezing chamber positioned in the refrigerating chamber.

[17] The apparatus for supercooling of claim 15, wherein the cool air generated in the refrigerating chamber is supplied to the non-freezing chamber.

[18] The apparatus for supercooling of claim 15, wherein the freezing cycle comprises an evaporator positioned on the rear face of the freezing chamber, part of the evaporator being extended to the non-freezing chamber to cool the non- freezing chamber.

[19] The apparatus for supercooling of claim 15, wherein the freezing cycle comprises an evaporator positioned on the rear face of the refrigerating chamber, part of the evaporator being extended to the non-freezing chamber to cool the non-freezing chamber.

[20] The apparatus for supercooling of claim 2, comprising a freezing chamber positioned at the upper portion and a refrigerating chamber positioned at the lower portion of the cooling chamber, wherein the non-freezing chamber is insulated by an insulation material and positioned in the freezing chamber. [21] The apparatus for supercooling of claim 2, comprising a freezing chamber positioned at the upper portion and a refrigerating chamber positioned at the lower portion of the cooling chamber, wherein the non-freezing chamber is positioned in a space separated from the refrigerating chamber and the freezing chamber.

[22] The apparatus for supercooling of claim 2, comprising a freezing chamber positioned at the lower portion and a refrigerating chamber positioned at the upper portion of the cooling chamber, wherein the non-freezing chamber is provided at the refrigerating chamber.

[23] The apparatus for supercooling of claim 22, wherein the cool air circulated in the freezing chamber is supplied to the non-freezing chamber positioned in the refrigerating chamber.

[24] The apparatus for supercooling of claim 22, wherein the cool air generated in the refrigerating chamber is supplied to the non-freezing chamber.

[25] The apparatus for supercooling of claim 22, wherein the freezing cycle comprises an evaporator positioned on the rear face of the freezing chamber, part of the evaporator being extended to the non-freezing chamber to cool the non- freezing chamber.

[26] The apparatus for supercooling of claim 22, wherein the freezing cycle comprises an evaporator positioned on the rear face of the refrigerating chamber, part of the evaporator being extended to the non-freezing chamber to cool the non-freezing chamber.

[27] The apparatus for supercooling of claim 2, comprising a freezing chamber positioned at the lower portion and a refrigerating chamber positioned at the upper portion of the cooling chamber, wherein the non-freezing chamber is insulated by an insulation material and positioned in the freezing chamber.

[28] The apparatus for supercooling of claim 2, comprising a freezing chamber positioned at the lower portion and a refrigerating chamber positioned at the upper portion of the cooling chamber, wherein the non-freezing chamber is positioned in a space separated from the refrigerating chamber and the freezing chamber.

[29] A method for defrosting an electrode of an apparatus for supercooling, comprising: a first step for judging whether the defrosting of the electrode is necessary; and a second step for operating a defrosting device. [30] The method of claim 29, wherein the first step comprises a process for measuring an intensity of an electric field. [31] The method of claim 30, wherein the first step comprises a process for judging whether the electrode has been frosted according to the intensity of the electric field. [32] The method of claim 29, wherein the first step decides whether or not to operate the defrosting device according to the operation time of the electrode. [33] The method of any one of claims 29 to 32, wherein the second step comprises a process for cutting off power of the electrode.