KR20250089032A - Heating device using rf energy - Google Patents

Abstract

The technical idea of the present invention (disclosure) relates to a heating device using RF energy, and more specifically, to a heating device using RF energy capable of evenly heating an object to be heated by uniformly radiating an electric field using a plurality of three-phase electrodes.

Description

HEATING DEVICE USING RF ENERGY

The technical idea of the present invention (disclosure) relates to a heating device using RF energy, and more specifically, to a heating device using RF energy capable of evenly heating an object to be heated by uniformly radiating an electric field using a plurality of three-phase electrodes.

The material described in this section merely provides background information for embodiments of the present invention and does not constitute prior art.

In general, a heating device called a microwave oven is a device that heats using microwaves, and is widely used due to its fast heating speed and convenience. However, since it provides a mechanically fixed frequency and output, it is difficult to maintain a uniform output or low output, and it is not easy to change multiplexing, so there is a problem that hot spots and cold spots occur, and the heating target, such as food, is not heated evenly.

To solve these problems, a heating device using RF energy has been developed. FIG. 1 is a schematic diagram of a conventional heating device using RF energy. Referring to FIG. 1, a heating device using RF energy generally includes a housing (1) in which a cavity (4) for accommodating a heating object is formed, a door (7) for opening and closing the housing (1), a first electrode (2) positioned on the lower side of the housing (1), a second electrode (3) positioned on the upper side of the housing (1), and an RF generator (5) connected to the first electrode (2) and the second electrode (3) to generate an RF signal, and according to signal transmission through the RF generator (5), an electric field is formed from the second electrode (3) toward the first electrode (2), and accordingly, the heating object (8) positioned between the first electrode (2) and the second electrode (3) is heated.

However, even in the case of heating devices using RF energy, there was a problem that the radiated electric field was concentrated at the edges and corners, causing local overheating.

Korean Patent Publication No. 10-2011-0084776 (July 26, 2011)

The technical idea of the present invention is to solve the above problems, and the technical problem to be achieved by the technical idea of the present invention relates to a heating device using RF energy capable of evenly heating a heating target object by uniformly radiating an electric field using a plurality of three-phase electrodes.

The technical problems to be solved by the technical idea of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

According to one embodiment of the present invention, a heating device using RF energy is disclosed, comprising: a first electrode provided inside a cavity and having a heating object placed on one side; a second electrode provided spaced apart from the first electrode and radiating an electric field to the heating object; and an RF generator electrically connected to the first electrode and the second electrode and generating an RF signal; wherein the second electrode is formed of a plurality of component electrodes provided spaced apart from each other.

At this time, the plurality of component electrodes may include a first component electrode positioned at the center; a second component electrode sharing a center with the first component electrode and formed spaced apart from the first component electrode; and a third component electrode sharing a center with the first component electrode and the second component electrode and formed spaced apart from the second component electrode.

At this time, the first component electrode may be formed in a circular shape, the second component electrode may be formed in an annular shape to include the first component electrode, and the third component electrode may be formed in an annular shape to include the second component electrode.

At this time, the width of the second component electrode can be formed wider than the width of the third component electrode.

Additionally, a first gap is formed between the first component electrode and the second component electrode, a second gap is formed between the second component electrode and the third component electrode, and the second gap can be formed to be wider than the first gap.

Meanwhile, at least one phase value applied to the first component electrode, the second component electrode, and the third component electrode can be formed differently.

Additionally, at least one of the amplitude values applied to the first component electrode, the second component electrode, and the third component electrode can be formed differently.

According to embodiments of the technical idea of the present invention, there is an effect of evenly heating an object to be heated by uniformly radiating an electric field using a plurality of three-phase electrodes.

The effects that can be obtained by the embodiments according to the technical idea of the present invention are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

In order to more fully understand the drawings cited in the present invention, a brief description of each drawing is provided.
Figure 1 is a schematic diagram of a conventional heating device using RF energy.
Figure 2 is a schematic diagram illustrating a heating device using RF energy according to the present invention.
FIG. 3 is a reference diagram for explaining the second electrode of a heating device using RF energy according to the present invention.
FIG. 4 and FIG. 5 are reference diagrams for explaining the effect of a heating device using RF energy according to the present invention.
FIG. 6 is a reference diagram for explaining the heating effect of a heating object by changing the phase of a plurality of second electrodes of a heating device using RF energy according to the present invention.
FIG. 7 is a reference diagram for explaining the heating effect of a heating object by changing the amplitude value of a plurality of second electrodes of a heating device using RF energy according to the present invention.

The technical idea of the present invention can have various modifications and various embodiments, and specific embodiments are illustrated in the drawings and described in detail through detailed description. However, this is not intended to limit the technical idea of the present invention to specific embodiments, and it should be understood that it includes all modifications, equivalents, and substitutes included in the scope of the technical idea of the present invention.

In explaining the technical idea of the present invention, if it is judged that a detailed description of related known technology may unnecessarily obscure the gist of the technical idea of the present invention, the detailed description thereof will be omitted. In addition, the numbers (e.g., first, second, etc.) used in the description of this specification are merely identifiers for distinguishing one component from another.

In addition, when it is mentioned in the present invention that a component is "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components in between. On the other hand, when it is mentioned that a component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between. Expressions that describe the relationship between components, such as "between" and "directly between" or "adjacent to" and "directly adjacent to", should also be interpreted in the same way.

The terminology used herein is for the purpose of describing specific embodiments only and is not intended to be limiting of the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. It should be understood that the terms "comprises" or "has" as used herein are intended to specify the presence of a described feature, number, step, operation, component, part, or combination thereof, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms defined in commonly used dictionaries, such as those defined in common usage, should be interpreted as having a meaning consistent with the meaning they have in the context of the relevant art, and shall not be interpreted in an idealized or overly formal sense unless expressly defined herein.

In addition, it should be clarified that the division of components in the present invention is only a division based on the main function of each component. In other words, two or more components to be described below may be combined into one component, or one component may be divided into two or more components based on more detailed functions. In addition to its own main function, each component to be described below may additionally perform some or all of the functions performed by other components, and it goes without saying that some of the main functions of each component may be performed exclusively by other components.

Hereinafter, a heating device using RF energy according to the present invention will be described in detail with reference to the attached drawings. In describing with reference to the attached drawings, identical or corresponding components are given the same drawing reference numerals and redundant descriptions thereof will be omitted. Hereinafter, embodiments according to the technical idea of the present invention will be described in detail one by one.

FIG. 2 is a schematic diagram for explaining a heating device using RF energy according to the present invention, FIG. 3 is a reference diagram for explaining a second electrode (30) of a heating device using RF energy according to the present invention, and FIGS. 4 and 5 are reference diagrams for explaining the effect of a heating device using RF energy according to the present invention. Hereinafter, a heating device using RF energy according to the present invention will be explained with reference to FIGS. 2 to 5.

A heating device using RF energy is formed with a housing having a cavity as an internal space and a door for opening and closing the housing, and a heating target (70), such as food, is positioned inside the cavity and heats the heating target (70) using RF energy.

A heating device using RF energy according to the present invention includes a first electrode (10), a second electrode (30), and an RF generator (50).

The first electrode (10) is provided inside the cavity, and a heating target (70) can be placed on one side.

The first electrode (10) is a conductive plate and may be provided inside the cavity. However, the first electrode (10) may be located in various spaces, such as the inner wall of the housing as well as the cavity, as long as the heating target (70) can be located.

The second electrode (30) is a conductive plate identical to the first electrode (10), and may be provided spaced apart from the first electrode (10). At this time, the first electrode (10) and the second electrode (30) may be formed of copper material. The second electrode (30) may be located in various spaces, such as not only the inside of the cavity but also the inner wall of the housing. At this time, the first electrode (10) may be located on the lower side of the cavity, and the second electrode (30) may be located spaced apart from the first electrode (10) on the upper side of the cavity.

When the heating target (70) is placed between the first electrode (10) and the second electrode (30), it is located above the first electrode (10).

The RF generator (50) is electrically connected to the first electrode (10) and the second electrode (30) to generate an RF signal. Specifically, the RF generator (50) generates and supplies an RF signal to the second electrode (30), and an electric field is radiated toward the first electrode (10) through the second electrode (30) into a cavity, which is an internal space of the housing. The thermal energy of the heating target (70) is increased by the electric field radiated onto the cavity, and thus the heating target (70) is heated.

At this time, the first electrode (10) can be grounded.

Meanwhile, the second electrode (30) of the heating device using RF energy according to the present invention may be formed of a plurality of component electrodes spaced apart from each other.

Specifically, referring to FIG. 3, the plurality of component electrodes may include a first component electrode (31), a second component electrode (33), and a third electrode.

The first component electrode (31) is formed as a conductive plate and may be located at the center. At this time, the first electrode (10) is formed in a square shape on a plane, and the center may be the center of the first electrode (10). At this time, the first component electrode (31) may be formed in a circular shape.

The second component electrode (33) is formed as a conductive plate, shares a center with the first component electrode (31), and can be formed spaced apart from the first component electrode (31). At this time, the second component electrode (33) can be formed in an annular shape to include the first component electrode (31).

The third component electrode (35) is formed as a conductive plate, shares a center with the second component electrode (33), and can be formed spaced apart from the second component electrode (33). At this time, the third component electrode (35) can be formed in an annular shape to include the second component electrode (33).

According to the present invention, a second electrode (30) to which an RF signal is applied through an RF generator (50) is formed by a plurality of constituent electrodes, and an RF signal applied to the plurality of constituent electrodes is controlled so that an electric field is uniformly radiated inside a cavity, thereby evenly heating a heating target (70) without local heating (see FIG. 2).

Meanwhile, referring to FIG. 3, the width (D1) of the second component electrode (33) may be formed wider than the width (D2) of the third component electrode (35). In the case of a conventional heating device using RF energy, the electric field radiated by the electrode is concentrated at the edges and corners, which may cause local overheating. Therefore, by forming the width (D1) of the second component electrode (33) located in the middle to be relatively wider than the width (D2) of the third component electrode (35), the intensity of the magnetic field radiated at the center is made relatively larger than the intensity of the magnetic field radiated at the edges and corners, thereby resolving the local heating phenomenon of the heating target object (70).

At this time, the radius of the first component electrode (31) may be 30 mm, the width of the second component electrode (33) may be 67 mm, and the width of the third component electrode (35) may be 39.5 mm.

In addition, a first gap may be formed between the first component electrode (31) and the second component electrode (33), and a second gap may be formed between the second component electrode (33) and the third component electrode (35). In consideration of electrical coupling between the first component electrode (31), the second component electrode (33), and the third component electrode (35), the second gap may be formed wider than the first gap.

At this time, a first gap between the first component electrode (31) and the second component electrode (33) can be formed as 6 mm, and a second gap between the second component electrode (33) and the third component electrode (35) can be formed as 15 mm.

FIGS. 4 and 5 are reference diagrams for explaining the effect of a heating device using RF energy according to the present invention. Hereinafter, the heating effect of a heating device using RF energy according to the present invention will be explained with reference to FIGS. 4 and 5.

First, the first electrode (10) is set to ground, and a voltage of 1000 V at a frequency of 27.12 MHz is applied to the second electrode (30) to generate an electric field, thereby radiating the electric field to the cavity.

The intensity of the generated electric field can be defined by the following equation (1).

1은 유전 물질의 비유전율이고, V는 E = ∇V에 의해 전기장과 관련된 전위이다.Here, σ is the electrical conductivity of the material, is the dielectric constant of air, i=

1 is the relative permittivity of the dielectric material, and V is the potential related to the electric field by E = ∇V.

Referring to Fig. 4, in order to measure the intensity of the electric field radiated to the heating target (70), a virtual x-axis and y-axis are set with the plane of the heating target (70) as the center as the origin, and 16 measurement points are set in one quadrant (quadrant 4 in this embodiment). At this time, the 16 measurement points can be set at regular intervals from each other.

And, the strength of the magnetic field was measured at 16 measurement points.

FIG. 5 (a) is a diagram showing the intensity of a magnetic field measured at 16 measurement points in order to analyze the electric field distribution applied to a heating object (70) when the second electrode (30) (drawing symbol deleted) of a heating device using RF energy according to a prior art is a single-phase electrode having a rectangular shape and to which a single-phase voltage is applied to the second electrode (30) (drawing symbol deleted), and FIG. 5 (b) is a diagram showing the intensity of a magnetic field measured at 16 measurement points in order to analyze the electric field distribution applied to a heating object (70) when the second electrode (30) according to the present invention is a three-phase electrode comprising a plurality of electrodes including a first component electrode (31), a second component electrode (33), and a third component electrode (35), and to which a three-phase voltage is applied to each of the component electrodes.

At this time, the voltage applied by the RF generator (50) to the second electrode (30) (drawing symbol deleted) of the heating device using RF energy according to the prior art and the second electrode (30) of the heating device using RF energy according to the present invention is the same as 1000 V at a frequency of 27.12 MHz, and the RF signal is applied with a phase difference of 45° to the first component electrode (31), 90° to the second component electrode (33), and 0° to the third component electrode (35).

Comparing the results of FIGS. 5 (a) and 5 (b), the electric field intensity of the heating device using RF energy according to the prior art showed a difference of 0.39 with a minimum of 1.0 and a maximum of 1.39, indicating that there was a large difference in the degree of heating due to local heating at the edges and corners (see FIG. 5 (a)), while the electric field intensity of the heating device using RF energy according to the present invention showed a difference of 0.11 with a minimum of 1.0 and a maximum of 1.11, indicating that similar electric field intensity was achieved at all measurement points, indicating that uniform heating was possible without local heating (see FIG. 5 (b)).

In this way, according to the present invention, the field intensity at the edge and corner of the magnetic field radiated into the cavity by the second electrode (30) is reduced to make the field intensity uniform in all areas, thereby evenly heating the heating target (70) without local heating, thereby achieving heating uniformity.

Meanwhile, FIG. 6 is a reference diagram for explaining the heating effect of a heating target (70) by changing the phase of a plurality of second electrodes (30) of a heating device using RF energy according to the present invention. Referring to FIG. 6, at least one phase value applied to the first component electrode (31), the second component electrode (33), and the third component electrode (35) can be formed to be different.

FIG. 6 (a) illustrates the electric field distribution of 16 measuring points when the phase of the first component electrode (31) changes. The phase of the first component electrode (31) is changed from 0° to 60° with a phase difference of 30°, while the second component electrode (33) and the third component electrode (35) maintain a fixed phase of 90°. As the phase of the first component electrode (31) increases, the electric field gradually expands from the center to the top of the measuring points, thereby changing the electric field intensity. In addition, when the phase of the first component electrode (31) changes from 0° to 60°, the electric field intensity of the measuring points located at the outskirts increased by 574 V/m from 16,037 V/m to 16,611 V/m, and the electric field intensity of the measuring points located at the corners increased by 312 V/m from 19,357 V/m. The electric field intensity slightly increased at the measurement points located at the edges and corners, while that at the measurement point located at the center increased by 3,895 V/m from 10,909 V/m to 14,804 V/m, approaching the electric field intensity of 16,611 V/m at the measurement point located at the edges. As a result, it can be confirmed that the electric field distribution uniformity improved by 15.25%, from 56.36% when the phase of the first component electrode (31) was 0° to 71.61% when it was 60°.

At this time, the electric field distribution uniformity (EDUI) can be defined by the following equation (2).

At this time, is the maximum electric field strength measured, is the minimum electric field strength measured, and a higher electric field distribution uniformity (EDUI) value indicates higher heating uniformity.

Fig. 6 (b) illustrates the electric field distribution of 16 measurement points when the phase of the second component electrode (33) is changed. The phase of the second component electrode (33) is changed from 30° to 60° with a phase difference of 30°, while the first component electrode (31) and the third component electrode (35) maintain a fixed phase of 0°. As the phase of the second component electrode (33) increases, the electric field is more concentrated on the second component electrode (33), and the excessive electric field applied to the measurement points located at the edges and corners is reduced. When the phase of the second configuration electrode (33) was changed from 30° to 60°, the electric field intensity of the measurement point located at the edge decreased by 1,442 V/m from 16,667 V/m to 15,225 V/m, and the electric field intensity of the measurement point located at the corner decreased by 1,958 V/m from 19,042 V/m to 17,084 V/m. In addition, the electric field intensity of the measurement point located at the center also decreased by 1,347 V/m from 14,057 V/m to 12,710 V/m.

In order to obtain high field uniformity of the electric field radiated from the second electrode (30), the electric field intensity in the central portion should be similar to the electric field intensity in the edge or corner portion. When the phases of the first component electrode (31) and the second component electrode (33) were adjusted to 60° and 30°, respectively, the electric field intensity in the central portion increased from 12,710 V/m to 13,839 V/m, and became closer to 15,514 V/m at the edge portion. In the case of the uniformity of the electric field distribution, there was no significant difference at 73.82% and 74.40% when the second component electrode (33) was 30° and 60°, respectively, but when the phase of the second component electrode (33) was 60° and the phase of the first component electrode (31) was changed to 30°, the uniformity of the electric field distribution increased to 80.75%, and it could be confirmed that by changing the phases of the second component electrode (33) and the first component electrode (31) simultaneously, the electric fields of the measurement points located at the edges and corners were weakened and the electric fields were concentrated at the measurement points located at the center.

FIG. 6 (c) illustrates the electric field distribution of 16 measuring points when the phase of the third component electrode (35) changes. The phase of the third component electrode (35) is changed from 60° to 0° with a phase difference of 30°, while the first component electrode (31) and the second component electrode (33) maintain a fixed phase of 90°. As the phase of the third component electrode (35) decreases, the electric field around the third component electrode (35) appears to become more concentrated, and when the phase of the third component electrode (35) changes from 60° to 0°, the electric field strength of the measuring points located at the edge decreases by 1,219 V/m from 16,740 V/m to 15,521 V/m, and the electric field of the measuring points located at the center decreases by 273 V/m from 14,425 V/m. On the other hand, the electric field at the measurement point located at the corner significantly decreased by 3,889 V/m, from 19,044 V/m to 15,155 V/m, so that the electric field intensity at the edge became close to that at the center. As a result of reducing the electric field distribution uniformity at the corner where the electric field intensity is the largest, the electric field distribution uniformity increased by 13.03%, from 75.75% at 60° phase to 88.78% at 0° phase.

Meanwhile, FIG. 7 is a reference diagram for explaining the heating effect of a heating target (70) by changing the amplitude values of a plurality of second electrodes (30) of a heating device using RF energy according to the present invention. Referring to FIG. 7, at least one amplitude value applied to the first component electrode (31), the second component electrode (33), and the third component electrode (35) can be formed to be different.

FIG. 7 (a) illustrates the electric field distribution according to the amplitude change of the first component electrode (31). The amplitude of the first component electrode (31) was changed from 800 V to 1600 V in intervals of 400 V, while the second component electrode (33) and the third component electrode (35) were maintained at a fixed amplitude of 900 V. As the amplitude of the first component electrode (31) increased, the electric field intensity increased, so the electric field became more concentrated, and when the amplitude of the first component electrode (31) changed from 800 V to 1600 V, the intensity of the electric field increased at the measurement points located at the edge and the corner. Specifically, the intensity of the electric field increased from 13,732 V/m to 14,669 V/m at the measurement point located at the edge, and from 15,772 V/m to 16,064 V/m at the measurement point located at the corner. The measurement points located at the edge showed an increase of 937 V/m, the measurement points located at the corners showed an increase of 292 V/m, and the measurement points located at the center showed a greater change. Specifically, the electric field intensity at the measurement point located at the center increased by 3,734 V/m, from 11,615 V/m at 800 V to 15,349 V/m at 1600 V. When the amplitude of the first configuration electrode (31) was changed from 800 V to 1600 V, the electric field distribution uniformity improved by 10.62%, from 73.64% to 84.26%.

Fig. 7 (b) illustrates the electric field distribution according to the amplitude change of the second component electrode (33). The amplitude of the second component electrode (33) was changed to 900 V and 700 V, and the first component electrode (31) and the third component electrode (35) were maintained at a fixed amplitude of 900 V. As the amplitude of the second component electrode (33) decreased, the electric field intensity generated from the electrode also decreased, which had an effect. As the amplitude of the second component electrode (33) decreased from 900 V to 700 V, the electric field intensity at the measurement point located at the edge decreased from 15,448 V/m to 13,073 V/m, and the electric field intensity at the measurement point located at the corner decreased from 17,743 V/m to 15,644 V/m. The electric field strength at the measurement point located in the center was reduced from 13,067 V/m to 11,254 V/m. The amplitude of the first component electrode (31) was adjusted to 1,400 V, and the amplitude of the second component electrode (33) was adjusted to 700 V to achieve similar electric field strength at the edge and corner, thereby improving the uniformity of the electric field distribution.

FIG. 7 (c) illustrates the electric field distribution according to the change in the amplitude of the third component electrode (35). The amplitude of the third component electrode (35) was changed from 1000 V to 500 V, and the first component electrode (31) and the second component electrode (33) were maintained at a fixed amplitude of 900 V. When the amplitude of the third component electrode (35) decreased, the electric field area between the electrodes became smaller and the electric current became lower. When the amplitude of the third component electrode (35) was changed from 1000 V to 500 V, the electric field intensity at the edge decreased by 2059 V/m from 15,860 V/m to 13,801 V/m, and the electric field intensity at the measurement point located in the center decreased by 396 V/m from 13,146 V/m to 12,750 V/m. In particular, the electric field strength at the measurement point located at the corner significantly decreased from 18,629 V/m to 14,204 V/m.

As the amplitude of the third component electrode (35) changed from 1000 V to 500 V, the uniformity of the electric field distribution significantly increased from 70.57% to 89.71%.

Thus far, preferred embodiments of a heating device using RF energy according to the present invention have been described. According to the present invention, by uniformly radiating an electric field using a plurality of three-phase electrodes, an effect of evenly heating an object to be heated can be obtained.

It should be understood that the above-described embodiments are illustrative in all respects and not restrictive, and the scope of the present invention will be indicated by the claims which follow rather than by the detailed description set forth above. And it should be construed that the meaning and scope of these claims, as well as all changes and modifications derived from the equivalent concept thereof, are included in the scope of the present invention.

10: 1st electrode
30: Second electrode
31: First component electrode
33: Second component electrode
35: Third component electrode
50: RF Generator
70: Heating target

Claims (7)

A first electrode provided inside a cavity and having a heating object placed on one side;
A second electrode provided spaced apart from the first electrode and radiating an electric field to the heating target; and
An RF generator electrically connected to the first electrode and the second electrode to generate an RF signal;
The second electrode is,
A heating device using RF energy, characterized in that it is formed by a plurality of component electrodes that are spaced apart from each other.
In the first paragraph,
A plurality of the above-described constituent electrodes are,
A first component electrode located at the center;
A second component electrode sharing a center with the first component electrode and formed spaced apart from the first component electrode; and
A heating device using RF energy, characterized by including a third component electrode that shares a center with the first component electrode and the second component electrode and is formed spaced apart from the second component electrode.
In the second paragraph,
The above first component electrode is formed in a circular shape,
The second component electrode is formed in an annular shape to include the first component electrode,
A heating device using RF energy, characterized in that the third component electrode is formed in an annular shape to include the second component electrode.
In the third paragraph,
A heating device using RF energy, characterized in that the width of the second component electrode is formed wider than the width of the third component electrode.
In the third paragraph,
A first gap is formed between the first component electrode and the second component electrode, and a second gap is formed between the second component electrode and the third component electrode.
A heating device using RF energy, characterized in that the second gap is formed wider than the first gap.
In the second paragraph,
A heating device using RF energy, characterized in that at least one phase value applied to the first component electrode, the second component electrode, and the third component electrode is formed differently.
In the second paragraph,
A heating device using RF energy, characterized in that at least one amplitude value applied to the first component electrode, the second component electrode, and the third component electrode is formed differently.