WO2008004762A1

WO2008004762A1 - Supercooling apparatus

Info

Publication number: WO2008004762A1
Application number: PCT/KR2007/002680
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: 2006-07-01
Filing date: 2007-06-01
Publication date: 2008-01-10
Also published as: KR20080003217A; WO2008004765A2; KR20080003215A; KR100857324B1; KR20080003218A; KR100827883B1; KR20080003220A; WO2008004763A1; WO2008004770A1; KR20080003222A; KR20070110465A; KR20080003228A; KR20080003219A; WO2008004764A3; KR20080003224A; KR100862107B1; WO2008004764A2; KR100850608B1; WO2008004761A2; KR100882625B1

Abstract

The present invention discloses a supercooling apparatus (200) which can stably maintain a stored object in a supercooled state for an extended period of time by supplying energy by generating an electric field, and which can improve the safety by stopping a non-freezing operation, when the electric field is leaked to the outside of a storage chamber maintaining a non-frozen state. The supercooling apparatus includes a storage chamber (B1C) for storing an object, a cooling cycle for supplying the cool air into the storage chamber outside the storage chamber, an energy supply unit (230) for generating an electric field in the storage chamber, and a sensing unit for sensing leakage of the electric field outside the stora e chamber.

Description

SUPERCOOLING APPARATUS

Technical Field

[1] The present invention relates to a supercooling apparatus, and more particularly, to a supercooling apparatus which can stably maintain a stored object in a supercooled state for an extended period of time by supplying energy by generating an electric field, and which can improve the safety by stopping a non-freezing operation, when the electric field is leaked to the outside of a storage chamber maintaining a non-frozen state. Background Art

[2] Supercooling means that a molten object or a solid cooled below a phase transition temperature in a balanced state is not changed. Each material has stable states in each temperature. If the temperature is slowly varied, elements of the material maintain the stable states in each temperature and accompany the variations of the temperature. However, if the temperature is sharply varied, the elements cannot be changed into the stable states in each temperature. Therefore, the elements of the material maintain the stable state of the start temperature, or some of the elements fail to be changed into the state of the final temperature.

[3] For example, when water is slowly cooled, it is not frozen temporarily at a temperature below 0°C. However, when water is supercooled, it has a kind of quasi- stable state. As this unstable balanced state is broken even by a slight stimulus, water tends to be changed into a more stable state. That is, if a small piece of material is put into the supercooled liquid, or if the liquid is suddenly shaken, the liquid is directly frozen so that the temperature of the liquid can reach the freezing point. Accordingly, the liquid maintains a stable balanced state at the temperature.

[4] Generally, foods such as vegetables, fruits, meats and beverages are refrigerated or frozen to be kept fresh. Such foods contain liquid elements such as water. If the liquid elements are cooled below a phase transition temperature, they are transited into solid elements after a predetermined time.

[5] A stored object such as water can be maintained in the non-frozen state for a short time. However, if moisture may be frozen in the food containing moisture, it is necessary to maintain the food in the non-frozen state for an extended period of time so as to keep quality of the food and preserve the food for a long time. Disclosure of Invention Technical Problem

[6] An object of the present invention is to provide a supercooling apparatus and a control method thereof which can stably maintain a stored object in a non-frozen state for an extended period of time. [7] Another object of the present invention is to provide a supercooling apparatus and a control method thereof which can sense leakage of an electric field supplied to maintain a non-frozen state. [8] Yet another object of the present invention is to provide a supercooling apparatus and a control method thereof which can improve the safety by stopping a non-freezing operation according to a degree of an electric field leaked to the outside of a storage chamber maintained in a non-frozen state. [9] Yet another object of the present invention is to provide a supercooling apparatus and a control method thereof which can sense and prevent leakage of an electric field, regardless of opening and closing of a storage chamber in the supercooling apparatus.

Technical Solution [10] In order to achieve the above-described objects of the invention, there is provided a supercooling apparatus, including: a storage chamber for storing an object; a cooling cycle for cooling the storage chamber; an energy supply unit for generating an electric field in the storage chamber; and a sensing unit for sensing leakage of the electric field outside the storage chamber. [11] Preferably, when the leakage degree of the electric field exceeds a reference value, the sensing unit stops generation of the electric field by the energy supply unit. [12] Preferably, the supercooling apparatus includes a control unit for receiving the leakage degree of the electric field from the sensing unit, and stopping generation of the electric field by the energy supply unit, when the leakage degree of the electric field exceeds a reference value. [13] Preferably, the sensing unit or the control unit cuts off power supply to the energy supply unit. [14] Preferably, the storage chamber is mounted in an inner housing space of a main body, and the sensing unit is mounted inside or outside the main body.

[15] Preferably, the storage chamber is opened and closed by a drawer or a sliding door.

[16] In another aspect of the present invention, a control method of a supercooling apparatus includes the steps of: performing a non-freezing operation by cooling a storage chamber and supplying an electric field to the storage chamber; sensing leakage of the electric field outside the storage chamber; and when the sensed leakage degree of the electric field exceeds a reference value, cutting off supply of the electric field.

[17] Preferably, the cut-off step cuts off power supply for supplying the electric field.

Brief Description of the Drawings

[18] 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:

[19] Fig. 1 is a conceptional view illustrating a basic electrode structure of a supercooling apparatus for maintaining a supercooled state;

[20] Fig. 2 is a graph showing a supercooling phenomenon in the supercooling apparatus of Fig. 1;

[21] Fig. 3 is an exemplary view illustrating the supercooling apparatus of Fig. 1;

[22] Fig. 4 is a perspective view illustrating a supercooling apparatus including a sensing unit;

[23] Fig. 5 is a configiration view illustrating a first example of the supercooling apparatus of Fig. 4;

[24] Fig. 6 is a configiration view illustrating a second example of the supercooling apparatus of Fig. 4; and

[25] Fig. 7 is a flowchart showing sequential steps of a control method of a supercooling apparatus. Mode for the Invention

[26] A supercooling apparatus in accordance with preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[27] If a liquid, for example, water is slowly cooled, it is not frozen temporarily at a temperature below 0°C. However, when water is supercooled, it has a kind of quasi- stable state. As this unstable balanced state is broken even by a slight stimilus, water tends to be changed into a more stable state. That is, if a small piece of material is put into the supercooled liquid, or if the liquid is suddenly shaken, the liquid is directly frozen so that the temperature of the liquid can reach the freezing point. Accordingly, the liquid maintains a stable balanced state at the temperature.

[28] Even if the temperature is lower than a phase transition temperature, if molecules can continuously perform at least one of rotation, vibration and translation, they can continuously maintain the supercooled state. That is, as soon as cooling which is a process of taking energy from the liquid is conducted, if energy is supplied to prevent phase transition from liquid to solid, the liquid state can be stably maintained for a long time even at a temperature lower than the phase transition temperature. Here, if the process of supplying energy is identical to the process of taking energy, they affect each other. Normally, a cooling apparatus uses a method of taking thermal energy. It is thus inappropriate to adopt a method of supplying thermal energy.

[29] Fig. 1 is a conceptional view illustrating a basic electrode structure of a supercooling apparatus for maintaining a supercooled state.

[30] Referring to Fig. 1, a casing 1 with a storage space Sl formed therein includes two electrodes 10a and 10b facing the storage space Sl. ^"A power supply unit 2 is provided to apply a high AC voltage to the electrodes 10a and 10b. The power supply unit 2 supplies energy to the storage space Sl between the electrodes 10a and 10b, by generating an electric field in the storage space Sl by applying the high AC voltage to the electrodes 10a and 10b.

[31] In addition, the storage space Sl is cooled by a cooling cycle (not shown). When thermal energy is taken from the storage space Sl, another kind of energy (namely, electric field energy) can be supplied thereto. Accordingly, when water or food containing moisture are stored in the storage space Sl, they can maintain a stable cooling state below a phase transition temperature for an extended period of time without being solidified or frozen.

[32] Fig. 2 is a graph showing a temperature when water kept in the supercooling apparatus of Fig. 1 is cooled.

[33] Generally, if water is cooled below a phase transition temperature, it is phase- transited.

[34] 0. l^of distilled water is put into the storage space S 1 of the casing 1 of Fig. 1. The electrodes 10a and 10b facing the storage space Sl have wider faces than the storage space Sl. The electrodes 10a and 10b are placed at an interval of 20mm. The casing 1 is made of an acrylic material, and inserted and cooled in a cooling space uniformly supplied with the cool air (namely, a refrigerating apparatus which does not have a supplementary electric field generator except the electrodes 10a and 10b).

[35] Here, the power supply unit 2 applies 0.91kV(6.76mA) and 2OkHz of AC voltage to the electrodes 10a and 10b, and the temperature inside the cooling space is about -7°C.

[36] As shown in Fig. 2, the supercooled state (non-frozen state) can be stably maintained for an extended period of time, by applying energy through the electric field.

[37] The supercooled state can be stably maintained for a long time by applying energy by generating the electric field. However, if the electric field is leaked, it may give stress to a human body, or cause heart disease, chemical change of blood, or change of hormone production. In order to protect the health of the user and improve the safety, if the electric field is leaked, it is necessary to stop generation of the electric field to prevent the leakage of the electric field.

[38] Fig. 3 is an exemplary view illustrating the supercooling apparatus of Fig. 1. The supercooling apparatus of Fig. 3 is an indirect-cooling type supercooling apparatus having a cooling cycle.

[39] The supercooling apparatus includes a casing 110 having one open face, a storage space A formed therein, and a shelf 130 for partially partitioning the storage space A, and a door 120 for opening and closing the opened face of the casing 110. A freezing cycle 30 of the indirect cooling type non-freezing refrigerator includes a compressor 32 for compressing a refrigerant, an evaporator 33 for generating the cool air (indicated by arrows) for cooling the storage space A or a stored object, a fan 34 for forcibly moving the generated cool air, a suction duct 36 for introducing the cool air into the storage space A, and a discharge duct 38 for inducing the cool air passing through the storage space A to the evaporator 33. Although not illustrated, the freezing cycle 30 may include a condenser, a drier and an expansion device. In the supercooling apparatus, the cooling cycle can be embodied as the direct cooling type as well as the indirect cooling type.

[40] Electrode units 50a and 50b are formed between the inner faces 112a and 112c facing the storage space A and the outer faces of the casing 110. The electrode units 50a and 50b are installed to face the storage space A, for applying an electric field to the whole storage space A. The storage space A is spaced apart from the ends of the electrode units 50a and 50b at predetermined intervals in the inward directions of the electrode units 50a and 50b or the center direction, so that a uniform electric field can be applied to the storage space A or the stored object. The supercooling apparatus includes a power supply unit (not shown) supplied with external common power, for generating high voltage AC power and applying it to the electrode units 50a and 50b. In addition, the supercooling apparatus may include a switch (not shown) for supplying and cutting off external common power to the power supply unit according to opening and closing of the door 120. When the user accesses and opens the door 120, the switch serves as a safety device for cutting off application of external common power to the power supply unit so as to stop generation of the electric field. On the contrary, when the door 120 is closed, namely, when the storage space A is closed, the switch operates to apply external common power to the power supply unit.

[41] The suction duct 36 and the discharge duct 38 are formed in the inner face 112b of the casing 110. The surfaces of the inner faces 112a, 112b and 112c of the casing 110 are made of a hydrophobic material, and thus are not frozen during a supercooling mode due to reduction of surface tension of water such as moisture. The outer faces and the inner faces 112a, 112b and 112c of the casing 110 are made of an insulation material, for preventing the user from receiving an electric shock from the electrode units 50a and 50b, and preventing the stored object from electrically contacting the electrode units 50a and 50b through the inner faces 112a, 112b and 112c.

[42] Fig. 4 is an exemplary view illustrating a supercooling apparatus including a sensing unit. In accordance with the present invention, in the supercooling apparatus

200, a refrigerating chamber and a freezing chamber are separately formed at both sides in a main body 201 having an open front face. A refrigerating chamber door 202a and a freezing chamber door 202b are hinge-coupled to the front face of the main body 201 to be opened and closed.

[43] Here, the main body 201 is partitioned off into the freezing chamber and the refrigerating chamber by a partition (not shown). An evaporator (not shown) and a cool air circulation fan (not shown) for blowing the cool air are built in the inner wall of the main body 201, and cool air supply holes (not shown) are formed in the main body

201, so that the cool air around the evaporator is supplied to and circulated in the freezing chamber and the refrigerating chamber.

[44] The refrigerating chamber door 202a and the freezing chamber door 202b have their one-side top and bottom ends hinge-coupled to the main body 201 by hinge covers 30 to be opened and closed.

[45] Identically to the storage space A of Fig. 3, storage chambers B and C supplied with the electric field and the cool air are installed in the freezing chamber. Electrodes are inserted into side faces of the storage chambers B and C, for supplying the cool air into the freezing chamber. The storage chamber B keeps a stored object in a drawer 204 which is opened and closed, and the storage chamber C is opened and closed by a sliding door 206 to take in or out a stored object. The supercooling apparatus 200 includes a power supply unit for applying a high AC voltage to the electrodes. The supercooling apparatus 200 may include a switch(not shown) for applying and cutting off external common power to the power supply unit, when the storage chambers B and C are opened and closed according to opening and closing of the doors 202a and 202b, opening and closing of the drawer 204, and opening and closing of the sliding door 206. The switch is a safety device for preventing generation of the electric field for the safety of the user.

[46] A sensing unit 210a for sensing the leakage degree of the electric field is mounted in the refrigerating chamber to be adjacent to the storage chamber B, for sensing the size or intensity of the electric field leaked from the storage chamber B. As the present invention is intended to prevent a human body from being damaged by the leaked electric field, it preferably conforms to the electromagnetic intensity standard for ordinary people in the electromagnetic human protection standard. For example, if the frequency of the electric field used in the present invention ranges from 3 to 50OkHz, the electric field mast be lower than 87(V/m). Accordingly, if an electric field sensor is employed, it mist perform different on/off operations under the electric field over 87(V/m) and the electric field below 87(V/m).

[47] A sensing unit 210b is mounted in the refrigerating chamber to be adjacent to the storage chamber C, for sensing the size or intensity of the electric field leaked from the storage chamber C.

[48] A sensing unit 210c is mounted outside the main body 201, for sensing the size or intensity of the electric field leaked from the storage chambers B and C.

[49] Here, the positions of the sensing units 210a, 210b and 210c are arbitrarily determined. That is, the sensing units 210a, 210b and 210c are installed to sense the leaked electric field. Therefore, when the electric field is leaked from the supercooling apparatus stably maintaining the non-frozen (pr supercooled) state for an extended period of time by using generation of the electric field, such sensing units serve to stop generation of the electric field, thereby protecting the health of the user and improving the safety.

[50] In the meantime, the electric field may be leaked regardless of opening and closing of the doors 202a and 202b, the drawer 204 or the sliding door 206. In case the leakage of the electric field is sensed by the sensing units 210a, 210b and 210c, generation of the electric field is stopped.

[51] Fig. 5 is a configiration view illustrating a first example of the supercooling apparatus of Fig. 4. The supercooling apparatus is provided with a safety device including a power supply unit 230 supplied with external common power, for generating high voltage power, a sensing unit 210 having a sensor unit 211 and a switch unit 212, and an electrode unit 220 applied with high voltage power, for generating an electric field. The sensing unit 210 indicates the above-described sensing units 210a, 210b and 210c. lower supply to the sensing unit 210 is individually configured, but omitted in this description. Such a power supply technique is easily recognized by the ordinary people in the art which the present invention pertains to.

[52] The supercooling apparatus includes a freezing cycle (not shown) for cooling the storage chambers B and C. The supercooling apparatus may selectively include an input unit for acquiring a control command from the user, a display unit for displaying the state of the supercooling apparatus, and a microcomputer for controlling execution of the non-freezing operation.

[53] The sensing unit 210 includes the sensor unit 211 for sensing the size or intensity of the electric field, and the switch unit 212 for supplying and cutting off high voltage power from the power supply unit 230 to the electrode unit 220 by the operation of the sensor unit 211. For example, if the sensor unit 211 senses the size or intensity of the electric field over a predetermined reference value, the sensor unit 211 directly controls the switch unit 212 to cut off supply of high voltage power. In addition, if the sensor unit 211 senses the size or intensity of the electric field below a predetermined reference value, the sensor unit 211 makes the power supply unit 230 to continuously supply high voltage power through the switch unit 212.

[54] The sensor unit 211 and the switch unit 212 may be integrally formed, so that the sensor unit 211 responds to the size or intensity of the electric field over a predetermined reference value, and cuts off supply of high voltage power.

[55] Fig. 6 is a configuration view illustrating a second example of the supercooling apparatus of Fig. 4. The supercooling apparatus is provided with a safety device including a power supply unit 230 supplied with external common power, for generating high voltage power, a switch unit 250 for supplying and cutting off high voltage power from the power supply unit 230 to an electrode unit 220, the electrode unit 220 for generating an electric field, a sensing unit 210' for sensing the size or intensity of the electric field, and a control unit 240 for supplying and cutting off high voltage power to the electrode unit 220, by controlling the switch unit 250 according to the sensing result of the sensing unit 210'. The sensing unit 210' indicates the above- described sensing units 210a, 210b and 210c. Ibwer supply to the sensing unit 210' and the control unit 240 is individually configured, but omitted in this description. Such a power supply technique is easily recognized by the ordinary people in the art which the present invention pertains to.

[56] The supercooling apparatus includes a freezing cycle (not shown) for cooling the storage chambers B and C. The supercooling apparatus may selectively include an input unit for acquiring a control command from the user, a display unit for displaying the state of the supercooling apparatus, and a microcomputer for controlling execution of the non-freezing operation.

[57] In this example, the sensing unit 210' can continuously sense the size or intensity of the electric field and transmit a sensing signal to the control unit 240 (first case), or transmit a sensing signal only when the size or intensity of the electric field is over or below a reference value (second case).

[58] In the first case, the control unit 240 compares the received sensing signal with the prestored reference value of the electric field. If the size or intensity of the electric field based on the sensing signal is over the reference value, the control unit 240 controls the switch unit 250 to cut off supply of high voltage power.

[59] In the second case, the control unit 240 instantaneously controls the switch unit 250 by reception of the sensing signal (transmitted only over the reference value) or non- reception of the sensing signal (transmitted only below the reference value).

[60] Fig. 7 is a flowchart showing sequential steps of a control method of the supercooling apparatus.

[61] In step S71, the supercooling apparatus performs the non-freezing operation by supplying the cool air through the cooling cycle and generating the electric field through the electrode unit.

[62] In step S72, the supercooling apparatus controls the sensing units 210a, 210b and

210c to sense the size or intensity of the electric field.

[63] In step S73, if the sensed size or intensity of the electric field exceeds the reference value, the routine goes to step S74, and if not, the routine goes back to step S72.

[64] In step S74, as described above with reference to Figs. 5 and 6, the supercooling apparatus stops generation of the electric field by execution of the non-freezing operation, by cutting off high voltage power applied to the electrode unit 220. Industrial Applicability

[65] The present invention can stably maintain the stored object in the non-frozen state

<pτ the supercooled state) for the extended period of time, by generating the electric field in the storage space and suppljing energy through the electric field.

[66] The present invention generates the electric field in the storage space and supplies energy through the electric field. When the electric field is leaked from the storage space, the present invention can stop generation of the electric field by using the sensing unit for sensing leakage of the electric field. [67] When the electric field is sensed by the sensing unit for sensing leakage of the electric field, the switch unit cuts off power supply to stop generation of the electric field. Therefore, the present invention can protect the health of the user and improve the safety.

[68] In addition to power cut-off by opening and closing of the storage chamber in the supercooling apparatus, the present invention senses and stops leakage of the electric field regardless of opening and closing of the storage chamber, namely, access and opening and closing by the user, thereby achieving the double safety effect.

[69] Although 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.

[70]

Claims

[1] A supercooling apparatus, comprising: a storage chamber for storing an object; a cooling cycle for cooling the storage chamber; an energy supply unit for generating an electric field in the storage chamber; and a sensing unit for sensing leakage of the electric field outside the storage chamber. [2] The supercooling apparatus of claim 1, wherein, when the leakage degree of the electric field exceeds a reference value, the sensing unit stops generation of the electric field by the energy supply unit. [3] The supercooling apparatus of claim 1, comprising a control unit for receiving the leakage degree of the electric field from the sensing unit, and stopping generation of the electric field by the energy supply unit, when the leakage degree of the electric field exceeds a reference value. [4] The supercooling apparatus of either claim 2 or 3, wherein the sensing unit or the control unit cuts off power supply to the energy supply unit. [5] The supercooling apparatus of claim 1, wherein the storage chamber is mounted in an inner housing space of a main body, and the sensing unit is mounted inside or outside the main body. [6] The supercooling apparatus of either claim 1 or 5, wherein the storage chamber is opened and closed by a drawer or a sliding door. [7] A control method of a supercooling apparatus, comprising the steps of: performing a non-freezing operation by cooling a storage chamber and supplying an electric field to the storage chamber; sensing leakage of the electric field outside the storage chamber; and when the sensed leakage degree of the electric field exceeds a reference value, cutting off supply of the electric field. [8] The control method of claim 7, wherein the cut-off step cuts off power supply for supplying the electric field.