refrigerator

Abstract

The present invention provides a refrigerator. The refrigerator includes a box body defining at least one accommodating space and a thawing device arranged in one of the accommodating spaces. The thawing device includes: a cylinder defining a thawing chamber with a forward opening for placing objects to be processed; a device door body arranged at the forward opening of the thawing chamber for opening and closing the thawing chamber; a radio frequency generating module configured to generate radio frequency signals in a frequency range of 40 to 42 MHz; and upper and lower electrode plates respectively arranged horizontally at the top and bottom walls of the thawing chamber and electrically connected to the radio frequency generating module, so as to generate radio frequency waves of corresponding frequencies in the thawing chamber according to the radio frequency signals, and thaw the objects to be processed in the thawing chamber. The inventor of the present application creatively discovered that the radio frequency waves in the frequency range of the present application have shorter thawing time, higher temperature uniformity and lower juice loss rate compared with radio frequency waves of other frequencies, and are particularly suitable for refrigerators.

Description

Technical Field

[0001] The invention relates to the field of thawing, in particular to a refrigerator with a rapid thawing function. Background Art

[0002] During the freezing process of food, the quality of the food is maintained, but the frozen food needs to be thawed before processing or eating. In order to facilitate users to freeze and thaw food, the prior art generally thaws food by arranging a heating device or a microwave device in the refrigerator.

[0003] However, thawing food by heating devices generally requires a long thawing time, and the thawing time and temperature are difficult to control, which can easily cause the evaporation of water and loss of juice in the food, resulting in loss of food quality; thawing food by microwave devices is fast and efficient, so the loss of food nutrients is very low, but due to the difference in the penetration and absorption of microwaves to water and ice, and the uneven distribution of internal materials in the food, the melted area absorbs more energy, which can easily cause uneven thawing and local overheating. Taking all factors into consideration, a refrigerator with high thawing efficiency, uniform thawing and guaranteed food quality is needed in design. Summary of the invention

[0004] An object of the present invention is to provide a refrigerator with high thawing efficiency, uniform thawing and guaranteed food quality.

[0005] A further object of the present invention is to improve the defrosting efficiency of a refrigerator.

[0006] Another further object of the present invention is to prevent the material to be treated from being over-thawed.

[0007] In particular, the present invention provides a refrigerator, comprising a box body defining at least one accommodating space and a thawing device disposed in one of the accommodating spaces, the thawing device comprising:

[0008] A cylinder body, in which a thawing chamber with a forward opening is defined, wherein the thawing chamber is used for placing objects to be processed;

[0009] A device door body, arranged at the front opening of the thawing chamber, for opening and closing the thawing chamber;

[0010] A radio frequency generating module configured to generate a radio frequency signal in the frequency range of 40 to 42 MHz; and

[0011] The upper electrode plate and the lower electrode plate are horizontally arranged at the top wall and the bottom wall of the thawing chamber, respectively, and are electrically connected to the radio frequency generating module, respectively, so as to generate radio frequency waves of corresponding frequencies in the thawing chamber according to the radio frequency signal, and thaw the objects to be processed in the thawing chamber.

[0012] Optionally, the radio frequency signal is a fixed frequency preset within the range of 40.48 to 40.68 MHz.

[0013] Optionally, the thawing device further comprises:

[0014] The detection module is configured to detect the incident wave signal and the reflected wave signal of the electrical connection connecting the RF generating module and the upper electrode plate, and calculate the load impedance of the RF generating module according to the voltage and current of the incident wave signal and the voltage and current of the reflected wave signal.

[0015] Optionally, the thawing device further comprises:

[0016] The load compensation module is configured to controllably increase or decrease the load impedance of the RF generation module, and make the difference between the load impedance and the output impedance of the RF generation module greater than or equal to a first impedance threshold and less than or equal to a second impedance threshold, so as to improve the thawing efficiency of the object to be processed.

[0017] Optionally, the load compensation module comprises a compensation unit connected in series with the object to be processed and a motor for increasing or decreasing the impedance of the compensation unit; wherein the motor is configured as follows:

[0018] When the difference between the load impedance and the output impedance of the RF generation module is less than the first impedance threshold, increasing the impedance of the compensation unit;

[0019] When the difference between the load impedance and the output impedance of the radio frequency generation module is greater than the second impedance threshold, the impedance of the compensation unit is reduced.

[0020] Optionally, the cylinder further comprises:

[0021] A vertical partition plate is arranged to extend from the top plate of the cylinder to the bottom plate of the cylinder in a vertical direction, and the radio frequency generating module is arranged between the vertical partition plate and the rear plate of the cylinder; and

[0022] The horizontal partition is arranged to extend forward from the vertical partition in a horizontal direction, and the detection module and the load compensation module are arranged between the horizontal partition and the top plate of the cylinder.

[0023] Optionally, the detection module is configured to further calculate the rate of change of the dielectric constant of the object to be processed according to the load impedance of the radio frequency generation module; and

[0024] The radio frequency generation module is configured as follows:

[0025] When the rate of change of the dielectric constant of the object to be processed is greater than or equal to a first rate threshold, the operating power is reduced by 30% to 40% to prevent the object to be processed from being over-thawed; and / or

[0026] When the change rate of the dielectric constant of the object to be processed drops to less than or equal to a second rate threshold, the operation is stopped.

[0027] Optionally, the thawing device further comprises:

[0028] An elastic conductive ring is arranged at the periphery of the forward opening so that it is squeezed and deformed when the device door is closed and fits tightly with the device door.

[0029] Optionally, the cylinder and the device door are respectively provided with electromagnetic shielding features; and

[0030] The electromagnetic shielding feature is configured to be in conductive contact with the elastic conductive ring to prevent the radio frequency waves generated by the thawing device from leaking out of the thawing device when the device door is closed.

[0031] Optionally, the cabinet further defines a compressor compartment, wherein the refrigerator further comprises:

[0032] A power supply module is arranged in the compressor room and is used to supply power to the radio frequency generating module.

[0033] The inventors of the present application creatively discovered that the radio frequency waves in the frequency range of the present application have a shorter thawing time, higher temperature uniformity and lower juice loss rate compared to radio frequency waves of other frequencies, and are particularly suitable for refrigerators.

[0034] Furthermore, the present invention detects the incident wave signal and the reflected wave signal of the electrical connection line connecting the radio frequency generating module and the upper electrode plate, and calculates the load impedance of the radio frequency generating module, which occupies a small space and has low cost, and is particularly suitable for the thawing device in the refrigerator. And through the load compensation module, the difference between the load impedance and the output impedance of the radio frequency generating module is within a preset range, which further improves the thawing efficiency of the object to be processed.

[0035] Furthermore, the present invention determines the thawing progress of the object to be treated by calculating the rate of change of the dielectric constant of the object to be treated through the detection module. Prior to the present invention, those skilled in the art generally believed that when the temperature of the object to be treated is already high (i.e., the temperature of the object to be treated is greater than or equal to -7°C), the thermal effect will be significantly attenuated, and thus the object to be treated will not be over-thawed. However, the actual situation is not the case. Usually, the radio frequency thawing power is relatively large, for example, greater than 100W. When the temperature of the object to be treated itself is already high, the object to be treated is very easy to be over-thawed. The inventors of the present application creatively realized that when the temperature of the object to be treated is already high, reducing the working power of the radio frequency generating module by 30 to 40% can effectively prevent the object to be treated from being over-thawed.

[0036] Furthermore, the present invention determines whether the thawing is completed by the rate of change of the dielectric constant of the object to be processed. Compared with the prior art in which the thawing is determined by sensing the temperature of the object to be processed, the determination is more accurate and can further prevent the object to be processed from being over-thawed. Tests show that the temperature of the object to be processed thawed by the thawing device of the present invention is generally -4 to -2°C when the thawing is completed, which can avoid the generation of blood when the object to be processed is meat.

[0037] Based on the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art will become more aware of the above and other objects, advantages and features of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings:

[0039] Figure 1 is a schematic structural diagram of a refrigerator according to an embodiment of the present invention, wherein all outer doors of the refrigerator are removed to illustrate the compartment structure within the refrigerator body;

[0040] Figure 2 yes Figure 1 A schematic cross-sectional view of the refrigerator shown;

[0041] Figure 3 yes Figure 2 A schematic partial enlarged view of the middle area A;

[0042] Figure 4 is along Figure 3 A schematic cross-sectional view taken along the cutting line BB in FIG.

[0043] Figure 5 is a schematic diagram of adjusting the load impedance of a radio frequency generating module according to an embodiment of the present invention;

[0044] Figure 6 is a curve diagram of the rate of change of the dielectric constant of the object to be processed according to one embodiment of the present invention;

[0045] Figure 7 yes Figure 2 A schematic structural diagram of the compressor room;

[0046] Figure 8 yes Figure 3 A schematic structural diagram of a thawing device in FIG. 1 , wherein a device door of the thawing device is removed to show the internal structure of the cylinder;

[0047] Fig. 9is a flow chart of a thawing method for a refrigerator according to an embodiment of the present invention. DETAILED DESCRIPTION

[0048] Figure 1 1 is a schematic structural diagram of a refrigerator 10 according to an embodiment of the present invention, wherein all outer doors of the refrigerator 10 are removed to illustrate the compartment structure within the cabinet 100 of the refrigerator 10; Figure 2 yes Figure 1 A schematic cross-sectional view of the refrigerator 10 is shown; Figure 3 yes Figure 2 Schematic partial enlargement of area A in FIG. Figures 1 to 3 , the refrigerator 10 may generally include a box body 100 defining at least one storage space, a compartment door for opening and closing the access openings of each storage space, and a thawing device 200 disposed in one storage space. In the illustrated embodiment, the number of the thawing device 200 is one.

[0049] Specifically, the thawing device 200 may include a cylinder 210, a device door 220, a radio frequency generating module 230, and an upper electrode plate 240a and a lower electrode plate 240b. The cylinder 210 may include a top plate, a bottom plate, a rear plate and two opposite lateral side plates, and a thawing chamber 214 with a forward opening may be defined therein, and the thawing chamber 214 is used to place the object to be processed. The device door 220 may be arranged at the forward opening of the thawing chamber 214, for opening or closing the thawing chamber 214. The device door 220 may be installed with the cylinder 210 by an appropriate method, such as a left-opening door, a right-opening door, an upper-opening door or a draw-out door. The radio frequency generating module 230 may be configured to generate a radio frequency signal (generally referring to a radio frequency signal with a frequency of 300KHz to 300GHz). The upper electrode plate 240a and the lower electrode plate 240b can be horizontally arranged at the top wall and the bottom wall of the thawing chamber 214, respectively, and are electrically connected to the radio frequency generating module 230, so as to generate radio frequency waves of corresponding parameters in the thawing chamber 214 according to the radio frequency signal generated by the radio frequency generating module 230, and thaw the objects to be processed placed in the thawing chamber 214. In the present invention, the upper electrode plate 240a is a transmitting antenna; the lower electrode plate 240b is a receiving antenna. In some embodiments, the upper electrode plate 240a and the lower electrode plate 240b can be electrically connected to the radio frequency generating module 230 respectively by using a 50 ohm electrical connection.

[0050] In some embodiments, the thawing device 200 may further include a detection module 250. The detection module 250 may be configured to detect the incident wave signal and the reflected wave signal of the electrical connection connecting the RF generation module 230 and the upper electrode plate 240a, and calculate the load impedance of the RF generation module 230 according to the voltage and current of the incident wave signal and the voltage and current of the reflected wave signal. The calculation formula of the load impedance is as follows:

[0051] SWR=Z2 / Z1 (1)

[0052] Z1=U1 / I1=R1+jX1 (2)

[0053] Z2=U2 / l2=R2+jX2 (3)

[0054] In formulas (1), (2) and (3): SWR is the standing wave ratio; Z1 is the output impedance; Z2 is the load impedance; U1 is the incident wave voltage; I1 is the incident wave current; R1 is the output resistance; X1 is the output reactance; U2 is the reflected wave voltage; I2 is the reflected wave current; R2 is the load resistance; X2 is the load reactance (those skilled in the art can understand that the output impedance is the impedance of the electrical connection connecting the RF generating module 230 and the upper electrode plate 240a, and the load impedance is the impedance of the object to be processed).

[0055] Figure 5 FIG. 1 is a schematic diagram of adjusting the load impedance of a radio frequency generating module according to an embodiment of the present invention. Figure 5 , the thawing device 200 may further include a load compensation module 260. The load compensation module 260 may include a compensation unit 261 and a motor 262 for adjusting the impedance of the compensation unit 261. The compensation unit 261 may be configured to be connected in series with the object to be processed, that is, at this time, the load impedance of the RF generation module 230 is the sum of the impedance of the object to be processed and the impedance of the compensation unit 261. The motor 262 may be configured to controllably increase or decrease the impedance of the compensation unit 261, thereby increasing or decreasing the load impedance Z2 of the RF generation module 230, and making the difference between the load impedance Z2 of the RF generation module 230 and the output impedance Z1 (i.e., the value obtained by subtracting the output impedance Z1 from the load impedance Z2) greater than or equal to a first impedance threshold and less than or equal to a second impedance threshold, and the first impedance threshold is less than the second impedance threshold, so as to improve the thawing efficiency of the object to be processed. In some preferred embodiments, the first impedance threshold is -6 to -4% of the output impedance Z1, and the second impedance threshold is 4 to 6% of the output impedance Z1. Further preferably, the first impedance threshold is -5% of the output impedance Z1, and the second impedance threshold is 5% of the output impedance Z1. In other words, the load compensation module can be configured to make the absolute value of the difference between the load impedance Z2 of the RF generation module 230 and the output impedance Z1 always less than 5% of the output impedance Z1 during the entire thawing process, for example, 1%, 3% or 5% of the output impedance Z1.

[0056] The detection module 250 can be configured to further calculate the dielectric constant and the rate of change of the dielectric constant of the object to be processed according to the load impedance Z2 of the RF generation module 230 to determine the thawing progress of the object to be processed. The calculation formula of the dielectric constant of the object to be processed is as follows:

[0057] X2=1 / 2πfC (4)

[0058] ε=4πKdC / S (5)

[0059] In formulas (4) and (5): f is the frequency of the radio frequency wave; C is the capacitance of the capacitor formed by the upper electrode plate 240a and the lower electrode plate 240b; ε is the dielectric constant of the object to be processed; K is the electrostatic constant; d is the thickness of the upper electrode plate; and S is the area of ​​the upper electrode plate.

[0060] The rate of change of the dielectric constant of the object to be processed can be obtained by calculating the change value Δε of the dielectric constant ε within a unit time Δt, wherein the unit time Δt can be 0.1 second to 1 second, such as 0.1 second, 0.5 second or 1 second. Figure 6 : is a curve diagram of the change rate of the dielectric constant of the object to be treated according to one embodiment of the present invention (the ordinate is the change rate Δε / Δt of the dielectric constant of the object to be treated; the abscissa is the thawing time t of the object to be treated, in min). Figure 6 In some preferred embodiments, the RF generation module 230 may be configured to reduce its operating power by 30% to 40%, such as 30%, 35% or 40%, when the rate of change Δε / Δt of the dielectric constant of the object to be processed is greater than or equal to the first rate threshold, so as to prevent the object to be processed from being over-thawed (thawed excessively means that the temperature of the object to be processed is greater than 0°C, as can be understood by those skilled in the art). The first rate threshold may be 15 to 20, such as 15, 17, 18 or 20. The RF generation module 230 may also be configured to stop working when the rate of change Δε / Δt of the dielectric constant of the object to be processed drops to less than or equal to the second rate threshold. The second rate threshold may be 1 to 2, such as 1, 1.5 or 2.

[0061] As the temperature of the object to be processed changes, the dielectric constant of the object to be processed will also change accordingly, which is well known to those skilled in the art. However, the dielectric constant is usually measured by a special instrument (such as a dielectric constant tester), and the special instrument occupies a large space and has a high cost, and is not suitable for refrigerators. The present invention detects the incident wave signal and the reflected wave signal of the electrical connection connecting the radio frequency generating module 230 and the upper electrode plate 240a, and calculates the dielectric constant of the object to be processed. It occupies a small space and has a low cost, and is particularly suitable for the thawing device in the refrigerator. And through the load compensation module 260, the difference between the load impedance and the output impedance of the radio frequency generating module 230 is within a preset range (greater than or equal to a first impedance threshold and less than or equal to a second impedance threshold), thereby improving the thawing efficiency of the object to be processed.

[0062] Furthermore, the present invention determines the thawing progress of the object to be treated by calculating the rate of change of the dielectric constant of the object to be treated through the detection module 250. Prior to the present invention, those skilled in the art generally believed that when the temperature of the object to be treated is already high (i.e., the temperature of the object to be treated is greater than or equal to -7°C), the thermal effect will be significantly attenuated, and thus the object to be treated will not be over-thawed. However, the actual situation is not the case. Usually, the radio frequency thawing power is relatively large, for example, greater than 100W. When the temperature of the object to be treated itself is already high, the object to be treated is very likely to be over-thawed. The inventors of the present application creatively realized that when the temperature of the object to be treated is already high, reducing the operating power of the radio frequency generating module 230 by 30 to 40% can effectively prevent the object to be treated from being over-thawed.

[0063] Furthermore, the present invention determines whether the thawing is completed by the rate of change of the dielectric constant of the object to be processed. Compared with the prior art in which the thawing is determined by sensing the temperature of the object to be processed, the determination is more accurate and can further prevent the object to be processed from being over-thawed. Tests show that the temperature of the object to be processed thawed by the thawing device of the present invention is generally -4 to -2°C when the thawing is completed, which can avoid the generation of blood when the object to be processed is meat.

[0064] In some embodiments, a thawing switch 124 for controlling the start or stop of the thawing program may be provided on any compartment door. The radio frequency generation module 230 may be configured to start working when the thawing switch 124 is turned on; and stop working when the thawing switch 124 is turned off. During the thawing process, the user can terminate the thawing program by turning off the thawing switch 124. In some preferred embodiments, the refrigeration system of the refrigerator 10 may be configured to stop providing cold air to the accommodation space provided with the thawing device 200 when the thawing switch 124 is turned on; and to run the original refrigeration program of the refrigerator 10 when the thawing switch 124 is turned off, so as to reduce the influence of the refrigeration system of the refrigerator 10 on the temperature of the thawing chamber 214 when the thawing device 200 thaws the object to be processed. The refrigeration system of the refrigerator 10 may include a compressor, a condenser, a capillary tube, and an evaporator for providing cold air.

[0065] A buzzer (not shown in the figure) may also be provided on any compartment door to remind the user that the object to be processed has been thawed. The buzzer may be configured to start working when the detection module 250 determines that the object to be processed has been thawed (when the rate of change of the dielectric constant of the object to be processed drops to less than or equal to the second rate threshold); and stop working when the object to be processed is taken out of the thawing chamber 214. An infrared sensor may be provided on the inner wall of the thawing chamber 214 to sense whether the object to be processed is placed in the thawing chamber 214.

[0066] Figure 7 yes Figure 2 Schematic diagram of the structure of the compressor chamber 140. Figure 7, the box body 100 of the refrigerator 10 is also defined with a compressor chamber 140. The compressor chamber 140 may include a main control board 143, a compressor 141, a condensed water collection structure 144, and an external power line (not shown in the figure) for powering the operation of the refrigerator 10, which are arranged in sequence. In some embodiments, the refrigerator 10 may also include a power supply module 142 for powering the radio frequency generation module 230. The power supply module 142 may be arranged in the compressor chamber 140 of the refrigerator 10 to facilitate heat dissipation and maintenance of the power supply module 142. The power supply module 142 may be fixed to the upper wall of the compressor chamber 140 to facilitate electrical connection between the radio frequency generation module 230 and the power supply module 142. In some embodiments, the power supply module 142 may be a DCDC converter. The DCDC converter may be arranged to be electrically connected to the main control board 143 to power the thawing device 200. The DCDC converter may be arranged between the main control board 143 and the compressor 141 to facilitate electrical connection between the main control board 143 and the main control board 143. In other embodiments, the power supply module 142 may be an ACDC converter. The ACDC converter may be configured to be electrically connected to an external power supply of the refrigerator 10. It is understandable to those skilled in the art that it is easy to connect the various components of the thawing device 200 to the control circuit of the refrigerator 10.

[0067] Figure 4 is along Figure 3 Schematic cross-sectional view taken along the section line BB in FIG. Figure 3 and Figure 4 , the cylinder 210 may further include a vertical partition 211 and a horizontal partition 212 for defining the internal space of the cylinder 210. The vertical partition 211 may be arranged to extend from the top plate of the cylinder 210 to the bottom plate of the cylinder 210 in the vertical direction. The radio frequency generation module 230 may be arranged between the vertical partition 211 and the rear plate of the cylinder 210. The horizontal partition 212 may be arranged to extend forward from the vertical partition 211 in the horizontal direction. The detection module 250 and the load compensation module 260 may be arranged between the horizontal partition 212 and the top plate of the cylinder 210. The thawing chamber 214 may be surrounded by the vertical partition 211, the horizontal partition 212, and the bottom plate and two lateral side plates of the cylinder 210. The upper electrode plate 240a may be arranged on the lower surface of the horizontal partition 212, and the lower electrode plate 240b may be arranged on the upper surface of the bottom plate of the cylinder 210. The cylinder 210 may further include a baffle 213 extending vertically upward from the front end of the horizontal partition 212 to the top plate of the cylinder 210 to prevent the detection module 250 and the load compensation module 260 from being exposed and reducing the aesthetics of the thawing device 200 .

[0068] In other embodiments, according to actual conditions (the size of the RF generating module 230, the detection module 250, and the load compensation module 260), the horizontal partition 212 can be set to extend forward from the rear plate of the cylinder 210 in the horizontal direction, and the vertical partition 211 can be set to extend from the horizontal partition 212 in the vertical direction to the bottom plate of the cylinder 210.

[0069] The vertical partition 211 may be provided with a first wire opening 2112, so that the RF generation module 230 is electrically connected to the upper electrode plate 240a via the first wire opening 2112. The rear plate of the cylinder 210 may be provided with a second wire opening 216, so that the power supply module 142 is electrically connected to the RF generation module 230 via the second wire opening 216.

[0070] In some embodiments, the rear plate of the cylinder 210 may be provided with a device air inlet 215, and the vertical partition 211 on the rear side of the thawing chamber 214 may be provided with a thawing air inlet 2111, so that the air in the accommodation space provided with the thawing device 200 enters the thawing chamber 214 of the thawing device 200 through the device air inlet 215 and the thawing air inlet 2111. The side plates on both lateral sides of the cylinder 210 may be provided with device air outlets 218, so that the gas in the thawing chamber 214 is discharged to the accommodation space through the device air outlets 218. The rear plate of the cylinder 210 may leave a gap with the rear wall of the accommodation space provided with the thawing device 200, so that the air in the accommodation space can enter the thawing device 200. The side plates on both lateral sides of the cylinder 210 may leave a gap with the side walls on both lateral sides of the accommodation space provided with the thawing device 200, so that the gas in the thawing device 200 can be discharged into the accommodation space. When the refrigerator 10 is a direct cooling refrigerator, the rear wall of the accommodating space is the rear wall of its inner container; when the refrigerator 10 is an air cooling refrigerator, the rear wall of the accommodating space is the front surface of its inner air duct cover.

[0071] In some preferred embodiments, the distance between the rear plate and the side plates on both sides of the cylinder 210 and the rear wall and the side walls on both sides of the corresponding accommodating space can be 2 to 3 mm, for example, 2 mm, 2.5 mm or 3 mm, so as to ensure that the thawing chamber 214 has a larger effective volume while ensuring that the thawing device 200 has appropriate air inlet and outlet volumes.

[0072] In some preferred embodiments, the device air inlet 215 and the thawing air inlet 2111 of the thawing device 200 can be respectively arranged on the lateral sides of the RF generation module 230 to facilitate the heat dissipation of the RF generation module 230. In some alternative embodiments, the device air inlet 215 and the thawing air inlet 2111 of the thawing device 200 can be arranged on the same side of the RF generation module 230.

[0073] In the present invention, the thawing device 200 is provided with a device air inlet 215 and a device air outlet 218. When no thawing instruction is received, the thawing chamber 214 can be used to place food, so that the storage space in the refrigerator 10 can be fully utilized.

[0074] The thawing device 200 may further include a tray 270. The tray 270 is disposed in the thawing chamber 214, and the object to be processed is placed on the tray 270. The tray 270 may be configured to be controllably movable in the depth direction of the thawing chamber 214 to facilitate the placement and removal of the object to be processed. In some preferred embodiments, the distance between the lower surface of the tray 270 and the lower electrode plate 240b may be 8 to 12 mm, such as 8 mm, 10 mm, or 12 mm, to prevent friction with the lower electrode plate 240b during the process of pulling the tray 270.

[0075] See also Figures 1 to 3 In some embodiments, the number of accommodating spaces of the refrigerator 10 may be three. Specifically, the refrigerator 10 may include a box 100 defining a refrigerating compartment 110, a variable temperature compartment 120, and a freezing compartment 130, and a refrigerating door body 111, a variable temperature door body 121, and a freezing door body 131 for opening and closing the refrigerating compartment 110, the variable temperature compartment 120, and the freezing compartment 130, respectively. The thawing device 200 may be disposed in the variable temperature compartment 120. The thawing device 200 may be fixed in the variable temperature compartment 120 by interference fit or snap-fit ​​with the inner walls on both sides of the variable temperature compartment 120 in the vertical direction. The thawing switch 124 may be disposed on the variable temperature door body.

[0076] In addition, it can also be explained that, as is well known to those skilled in the art, the refrigerated compartment 110 refers to a storage compartment with a storage temperature of 0 to +8°C for food; the frozen compartment 130 refers to a storage compartment with a storage temperature of -20 to -15°C for food; the variable temperature compartment 120 refers to a storage compartment whose storage temperature can be changed within a relatively large range (for example, the adjustment range can be above 4°C and can be adjusted to above 0°C or below 0°C), and generally its storage temperature can span refrigeration, soft freezing (generally -4 to 0°C) and freezing temperatures, preferably -16 to +4°C.

[0077] In some embodiments, the refrigerator 10 according to the present invention may be an air-cooled refrigerator, and the variable temperature compartment 120 may include an air duct cover plate 122. The air duct cover plate 122 and the rear wall of the inner tank of the variable temperature compartment 120 are sandwiched to form a variable temperature air duct, and a variable temperature air inlet 1221 is provided on the air duct cover plate 122 to provide cold air for the variable temperature compartment 120. In some preferred embodiments, the device air inlet 215 of the thawing device 200 and the variable temperature air inlet 1221 may be connected through a connecting pipe 123, so as to facilitate refrigeration of the thawing chamber 214 of the thawing device 200. In other preferred embodiments, the projection of the device air inlet 215 of the thawing device 200 in the thickness direction of the rear plate of the barrel 210 may be within the variable temperature air inlet 1221, so as to facilitate refrigeration of the thawing chamber 214 of the thawing device 200.

[0078] A variable temperature air inlet damper 1222 may be provided at the variable temperature air inlet 1221 to conduct or block the variable temperature air duct. The variable temperature air inlet damper 1222 may be configured as follows: when the RF generating module 230 is in working state, the variable temperature air inlet damper 1222 is closed, that is, the variable temperature air duct stops providing cold air to the variable temperature chamber 120, so as to avoid affecting the thawing of the thawing device 200 to thaw the processed object; when the RF generating module 230 is in non-working state, the variable temperature air inlet damper 1222 is opened, that is, the variable temperature air duct can provide cold air to the variable temperature chamber 120, and the thawing chamber 214 is used to place food.

[0079] Figure 8 yes Figure 3 Schematic structural diagram of the thawing device 200, wherein the device door of the thawing device is removed to show the internal structure of the cylinder. Figure 8, the thawing device 200 may further include an elastic conductive ring 280. The elastic conductive ring 280 may be disposed at the periphery of the forward opening of the thawing chamber 214 so that it is squeezed and deformed when the device door 220 is closed, and is closely fitted with the device door 220, that is, a seal is formed between the elastic conductive ring 280 and the device door 220. In some preferred embodiments, the elastic conductive ring 280 may be made of silicone, silicone fluoride, EPDM, fluorocarbon-silicon fluoride and silver-plated aluminum. The elastic conductive ring 280 may be a hollow annular structure so that it is closely fitted with the device door 220 when the device door 220 is closed. The width of the elastic conductive ring 280 may be set to 20 to 30 mm, such as 20 mm, 25 mm or 30 mm, to improve the sealing of the thawing device 200. The cylinder 210 and the device door 220 may be provided with electromagnetic shielding features 217, respectively. The electromagnetic shielding feature 217 provided on the cylinder 210 and the electromagnetic shielding feature 217 provided on the device door 220 can be respectively provided to be in conductive contact with the elastic conductive ring 280, so as to reduce the magnetic leakage outward from the thawing device 200 when the device door 220 is closed, and reduce the harm to the human body. The electromagnetic shielding feature 217 can be a conductive coating coated on the inner wall of the cylinder 210 and the inner surface of the device door 220 (the surface facing the cylinder 210), a conductive metal mesh attached to the inner wall of the cylinder 210 and the inner surface of the device door 220, or a conductive metal mesh formed in each plate body surrounding the cylinder 210 and in the device door 220, etc. In some preferred embodiments, the device air inlet 215, the thawing air inlet 2111 and the device air outlet 218 of the thawing device 200 may all be provided with a conductive metal mesh 290, and the conductive metal mesh 290 may be configured to be conductively connected to the electromagnetic shielding feature 217 provided on the cylinder 210 to reduce the magnetic leakage of the thawing device 200.

[0080] In particular, in the present invention, the frequency of the radio frequency signal generated by the radio frequency generating module 230 (i.e., the electromagnetic wave used to thaw the object to be processed) can be 40 to 42 MHz, such as 40 MHz, 40.48 MHz, 40.68 MHz, 41 MHz or 42 MHz, so as to reduce the thawing time of the object to be processed, improve the temperature uniformity of the object to be processed and reduce its juice loss rate. In a preferred embodiment, the frequency of the radio frequency wave can be a preset fixed frequency within the range of 40.48 to 40.68 MHz, so as to further reduce the thawing time of the object to be processed, improve the temperature uniformity of the object to be processed and reduce its juice loss rate. Among them, when the frequency of the radio frequency wave is 40.68 MHz, the thawing effect is best.

[0081] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with more specific examples, but the present invention is not limited to these examples.

[0082] Table 1

[0083] Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Frequency (MHz) 40 40.48 40.68 41 42 13.56 27.12

[0084] In the thawing devices 200 respectively provided with the radio frequency frequencies of the above-mentioned embodiments 1-5 and comparative examples 1-2, the power of the radio frequency waves is 100 W, and the structure and working process of the thawing devices 200 are the same.

[0085] The thawing effect test was conducted on the thawing device 200 provided with the frequency of each embodiment and each comparative example. Test description: 1 kg of beef with the same shape and specification and an initial temperature of -18°C was selected and placed on the tray 270 in the thawing device 200 of each embodiment and each comparative example, and the thawing time, temperature uniformity and juice loss rate of each embodiment and each comparative example were measured respectively, wherein the thawing time is the time from the start of thawing to the thawing device 200 judging that the thawing is completed (i.e., the radio frequency generating module stops working); temperature uniformity: after the thawing is completed, the temperature of the four corners and the center point of the beef is measured respectively, and the difference between the center point temperature and the average value of the four corners is calculated, and the temperature uniformity is the ratio of the difference to the average value; juice loss rate: the weight of the beef before thawing and the weight after thawing are measured respectively, and the difference between the two is calculated, and the juice loss rate is the ratio of the difference to the weight of the beef before thawing.

[0086] The thawing effect test results according to Examples 1-7 and Comparative Examples 1-2 are shown in Table 2.

[0087] Table 2

[0088] Thawing time (min) Temperature uniformity Juice loss rate (%) Example 1 19 0.4 0.35 Example 2 18 0.4 0.32 Example 3 18 0.3 0.29 Example 4 19 0.5 0.35 Example 5 20 0.5 0.40 Comparative Example 1 25 0.6 0.35 Comparative Example 2 23 0.6 0.40

[0089] According to the test results of Example 5 and Comparative Example 1 in Table 2, it can be seen that when the power of the radio frequency wave is the same, and the structure and working process of the thawing device 200 are the same, under the same test conditions, the thawing effect of the thawing device 200 using the radio frequency frequency within the scope of the embodiment of the present invention is better than the thawing device 200 using the radio frequency frequency in the prior art. The former reduces the thawing time by 20% and improves the temperature uniformity by 17%.

[0090] According to the test results of Examples 1-5 in Table 2, it can be seen that the thawing time of the thawing device 200 using each embodiment of the present invention is less than 20 minutes, the temperature uniformity is less than 0.5, and the juice loss rate is less than 0.40%. By further optimizing the frequency of the radio frequency wave (for example, the radio frequency frequency is 40.48-40.68MHz), the thawing time of the thawing device 200 can be reduced to less than 18 minutes, the temperature uniformity is increased to less than 0.4, and the juice loss rate is reduced to less than 0.32%.

[0091] Fig. 9FIG. 1 is a flow chart of a defrosting method for a refrigerator 10 according to an embodiment of the present invention. Fig. 9 The thawing method of the refrigerator 10 of the present invention may include the following steps:

[0092] Step S902: Determine whether the thawing switch 124 is turned on. If so, execute step S904; if not, execute step S902.

[0093] Step S904: the power supply module 142 starts working.

[0094] Step S906: Determine whether the device door 220 is closed. If so, execute step S908; if not, execute step S906. In this step, the door opening detection device can be used to detect the open and closed state of the device door 220. The door opening detection device can be used in a variety of ways such as a fan switch, a magnetic switch, and a Hall switch to detect, and generate different electrical signals when the device door 220 is completely closed or opened to indicate the state of the device door 220.

[0095] Step S908: The refrigeration system stops providing coldness to the storage space where the thawing device 200 is installed, the radio frequency generation module 230 generates a radio frequency signal of 40-42 MHz, and the detection module 250 detects the incident wave signal and the reflected wave signal of the electrical connection line connecting the radio frequency generation module 230 and the upper electrode plate 240a. Steps S910 and S911 are executed. In this step, the thawing device 200 is installed in the variable temperature chamber 120, and the radio frequency generation module 230 generates a radio frequency signal of 40.68 MHz.

[0096] Step S910: Obtain the voltage and current of the incident wave signal and the voltage and current of the reflected wave signal, and calculate the rate of change Δε / Δt of the dielectric constant of the object to be processed.

[0097] Step S912: Determine whether the rate of change Δε / Δt of the dielectric constant of the object to be processed is greater than or equal to a first rate threshold. If so, execute step S914; if not, execute step S910.

[0098] Step S914: The working power of the RF generation module 230 is reduced by 30% to 40%. In this step, the working power of the RF generation module 230 can be reduced by 35%.

[0099] Step S916: Obtain the voltage and current of the incident wave signal and the voltage and current of the reflected wave signal, and calculate the rate of change Δε / Δt of the dielectric constant of the object to be processed.

[0100] Step S918: Determine whether the rate of change Δε / Δt of the dielectric constant of the object to be processed is less than or equal to a second rate threshold. If so, execute step S920; if not, execute step S916.

[0101] Step S920: the power supply module 142 stops working, the defrost switch 124 is reset (ie, closed), the original refrigeration program of the refrigerator 10 is run, and the buzzer starts working.

[0102] Step S922: Determine whether the object to be processed is taken out from the thawing chamber 214. If so, execute step S924; if not, execute step S922.

[0103] Step S924: The buzzer stops working.

[0104] Step S911 : obtaining the voltage and current of the incident wave signal and the voltage and current of the reflected wave signal, and calculating the load impedance Z2 of the RF generation module 230 .

[0105] Step S913: Determine whether the difference between the load impedance Z2 and the output impedance Z1 of the RF generating module 230 is less than the first impedance threshold. If so, execute step S915; if not, execute step S917.

[0106] Step S915: The motor 262 of the load compensation module 260 operates to increase the impedance of the compensation unit 261. Return to step S911.

[0107] Step S917: Determine whether the difference between the load impedance Z2 and the output impedance Z1 of the RF generating module 230 is greater than the second impedance threshold. If so, execute step S919; if not, execute step S911.

[0108] Step S919: The motor 262 of the load compensation module 260 operates to reduce the impedance of the compensation unit 261. Return to step S911.

[0109] Those skilled in the art can understand that when the program runs to step S920, the power supply module 142 stops working, that is, it stops supplying power, and the RF generation module 230, the detection module 250 and the load compensation module 260 all stop working, that is, when the rate of change Δε / Δt of the dielectric constant of the object to be processed drops to less than or equal to the second rate threshold, the detection module 250 stops detecting the incident wave signal and the reflected wave signal of the electrical connection connecting the RF generation module 230 and the upper electrode plate 240a, and the load compensation module 260 stops working.

[0110] A defrosting process of the refrigerator 10 according to an embodiment of the present invention may include: when the user turns on the defrosting switch 124 and the device door 220 is closed, the power supply module 142 starts to supply power, the refrigeration system of the refrigerator 10 stops providing cold air to the storage space provided with the defrosting device 200, the radio frequency generation module 230 generates a 40.68 MHz radio frequency signal, and the detection module 250 and the load compensation module 260 start to work. The detection module 250 detects the incident wave signal and the reflected wave signal of the electrical connection line connecting the radio frequency generation module 230 and the upper electrode plate 240a, and calculates the load impedance Z2 of the radio frequency transmitting device 230 and the rate of change of the dielectric coefficient Δε / Δt. When the rate of change Δε / Δt of the dielectric constant of the object to be processed is greater than or equal to the first rate threshold, the working power of the RF generation module 230 is reduced by 35%. At the same time, in the entire thawing process, when the difference between the load impedance Z2 and the output impedance Z1 of the RF generation module 230 is less than the first impedance threshold or greater than the second impedance threshold, the load compensation module 260 adjusts the impedance of the compensation unit 261 through the motor 262, and then adjusts the load impedance Z2 of the RF generation module 230, so that the difference between the load impedance Z2 and the output impedance Z1 of the RF generation module 230 is always greater than or equal to the first impedance threshold and less than or equal to the second preset threshold. When the rate of change Δε / Δt of the dielectric constant of the object to be processed is less than or equal to the second rate threshold, the power supply module 142 stops supplying power, runs the original refrigeration program of the refrigerator 10, the RF generation module 230, the detection module 250, and the load compensation module 260 stop working, and the buzzer starts working. When the user takes out the object to be processed from the thawing chamber 214, the buzzer stops working.

[0111] At this point, those skilled in the art should recognize that, although multiple exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications that conform to the principles of the present invention can still be directly determined or derived based on the content disclosed in the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and recognized as covering all these other variations or modifications.

Claims

1. A refrigerator, comprising a box body defining at least one accommodating space and a thawing device disposed in one of the accommodating spaces, the thawing device comprising: A cylinder body, in which a thawing chamber with a forward opening is defined, wherein the thawing chamber is used for placing objects to be processed; A device door body, arranged at the front opening of the thawing chamber, for opening and closing the thawing chamber; A radio frequency generating module is configured to generate a radio frequency signal in a frequency range of 40 to 42 MHz; and The upper electrode plate and the lower electrode plate are respectively arranged horizontally at the top wall and the bottom wall of the thawing chamber, and are respectively electrically connected to the radio frequency generating module to generate radio frequency waves of corresponding frequencies in the thawing chamber according to the radio frequency signal, and thaw the objects to be processed in the thawing chamber; wherein the radio frequency generating module is configured as follows: When the change rate of the dielectric constant of the object to be processed is greater than or equal to a first rate threshold, the working power is reduced by 30% to 40% to prevent the object to be processed from being over-thawed; When the change rate of the dielectric constant of the object to be processed drops to less than or equal to a second rate threshold, the operation is stopped.

2. The refrigerator according to claim 1, wherein The radio frequency signal is a fixed frequency preset within the range of 40.48 to 40.68 MHz.

3. The refrigerator according to claim 1, wherein the thawing device further comprises: The detection module is configured to detect the incident wave signal and the reflected wave signal of the electrical connection connecting the RF generating module and the upper electrode plate, and calculate the load impedance of the RF generating module according to the voltage and current of the incident wave signal and the voltage and current of the reflected wave signal.

4. The refrigerator according to claim 3, wherein the thawing device further comprises: The load compensation module is configured to controllably increase or decrease the load impedance of the RF generation module, and make the difference between the load impedance and the output impedance of the RF generation module greater than or equal to a first impedance threshold and less than or equal to a second impedance threshold, so as to improve the thawing efficiency of the object to be processed.

5. The refrigerator according to claim 4, wherein The load compensation module includes a compensation unit connected in series with the object to be processed and a motor for increasing or decreasing the impedance of the compensation unit; wherein the motor is configured as follows: When the difference between the load impedance and the output impedance of the RF generation module is less than the first impedance threshold, increasing the impedance of the compensation unit; When the difference between the load impedance and the output impedance of the radio frequency generation module is greater than the second impedance threshold, the impedance of the compensation unit is reduced.

6. The refrigerator according to claim 4, wherein the cylinder further comprises: A vertical partition is arranged to extend from the top plate of the cylinder to the bottom plate of the cylinder in a vertical direction, and the radio frequency generating module is arranged between the vertical partition and the rear plate of the cylinder; and The horizontal partition is arranged to extend forward from the vertical partition in a horizontal direction, and the detection module and the load compensation module are arranged between the horizontal partition and the top plate of the cylinder.

7. The refrigerator according to claim 1, wherein The refrigerator is configured to calculate a rate of change of a dielectric constant of the object to be processed according to a load impedance of the radio frequency generating module.

8. The refrigerator according to claim 1, wherein the thawing device further comprises: An elastic conductive ring is arranged at the periphery of the forward opening so that it is squeezed and deformed when the device door is closed and fits tightly with the device door.

9. The refrigerator according to claim 8, wherein The cylinder and the device door are respectively provided with electromagnetic shielding features; and The electromagnetic shielding feature is configured to be in conductive contact with the elastic conductive ring to prevent the radio frequency waves generated by the thawing device from leaking out of the thawing device when the device door is closed.

10. The refrigerator according to claim 1, wherein the cabinet further defines a compressor compartment, wherein the refrigerator further comprises: A power supply module is arranged in the compressor room and is used to supply power to the radio frequency generating module.

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