A defrosting device, a defrosting method, and a refrigerator

Abstract

This invention provides a thawing device, a thawing method, and a refrigerator. The thawing device can automatically determine the weight of the object to be thawed based on its initial thawing temperature and the thawing frequency where the optimal electromagnetic wave absorption efficiency is located. It calculates S-parameters based on Pin and Pref1 of the thawing frequency where the optimal electromagnetic wave absorption efficiency is located, determines the fat content of the object based on the S-parameters of the thawing frequency where the optimal electromagnetic wave absorption efficiency is located, and determines a thawing strategy based on the initial thawing temperature, weight, and fat content of the object. This invention ensures that the thawing strategy is applicable to objects of various compositions, guarantees the thawing effect, ensures that the degree of thawing meets user needs, and ensures that the quality of the object is not affected by the thawing process.

Description

Technical Field

[0001] This invention belongs to the technical field of defrosting devices, specifically relating to a defrosting device, a defrosting method, and a refrigerator having the defrosting device. Background Technology

[0002] Freezing technology has long been used by food producers, home and commercial kitchen users as an effective method to maintain the freshness and quality of agricultural and aquatic products and other processed foods. The equipment used in freezing technology, such as refrigerators and freezers, is very mature and has achieved a high degree of adoption.

[0003] The freezer compartment of a typical household refrigerator (with a typical temperature of -18℃) is used to store food that will not be eaten for a short period of time, especially various kinds of meat. Before cooking food stored in the freezer, users usually need to thaw the frozen food to a target temperature of around -5℃ to 0℃. Meat at this temperature is easy to cut and will not be difficult to cut due to the low temperature. If the temperature is too high, it will be difficult to cut and the cut pieces or slices of meat will not be well-shaped.

[0004] Currently, the main defrosting methods used in home kitchens and their drawbacks are as follows:

[0005] Air thawing and refrigerated thawing are simple to operate, but if the thawing time is too long, the surface of the food is easily oxidized, and the juices are lost in large quantities after thawing.

[0006] Water thawing is not only time-consuming, but bacteria and microorganisms can easily grow on the surface of food during the thawing process, seriously affecting food quality.

[0007] Defrost using heating wires or heating tubes is inefficient and results in uneven temperatures for the defrosted food.

[0008] When microwave ovens using magnetron technology defrost food, the magnetron, as the emission source, cannot control the phase of the emitted electromagnetic waves, resulting in poor directionality. This leads to uneven heating inside and outside the food, causing excessive temperature differences between the inside and outside of the defrosted food, excessive loss of juices, and serious damage to the quality of the food.

[0009] The planar capacitor defrosting system operates at a frequency of 40.68MHz. The principle is that an RF signal source, through an RF matching device, generates a voltage of several kilovolts on parallel metal plates, creating an electric field between the two plates, similar to a capacitor. This electric field is then used to defrost the food. The disadvantages of this approach are: the selected frequency band is relatively low, and the ring isolators for this band are too large to use, resulting in poor isolation between the RF module's transmit and receive links. Changes in the defrosted food often worsen the transmit matching, causing power backflow into the receive link and potentially burning it out, thus leading to low reliability. Furthermore, its operating principle dictates the generation of several kilovolts on the capacitor plates, which compromises product safety. Some solutions also employ relay switching for frequency tuning and / or power adjustment, introducing noise.

[0010] Thawing devices that emit electromagnetic waves of a specific frequency offer high thawing efficiency and good temperature uniformity. However, in these devices, thawing time is typically determined by the surface temperature and weight of the food to be thawed. Since the composition of the food varies—for example, fish and meat of the same weight and surface temperature have completely different compositions—the thawing strategies are not universally applicable. Therefore, using the same thawing strategy for different types of food with varying compositional contents can lead to over-thawing, under-thawing, or altered quality after thawing.

[0011] The information disclosed in this background section is only intended to enhance the understanding of the background technology of this application, and therefore may include prior art that is not known to those skilled in the art. Summary of the Invention

[0012] The purpose of this invention is to provide a thawing device with high thawing efficiency and good temperature uniformity, so as to solve the problems of over-thawing, insufficient thawing, or changes in quality after thawing caused by using the same thawing strategy for different types of materials with different component contents in existing thawing devices.

[0013] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0014] A defrosting device, comprising:

[0015] The thawing chamber is used to hold the items to be thawed;

[0016] The thawing antenna is located inside the thawing cavity;

[0017] A radio frequency power source is used to generate radio frequency signals within a fixed frequency range and transmit them through the defrosting antenna;

[0018] The device includes:

[0019] An incident power detection module is used to detect the electromagnetic wave power Pin transmitted from the radio frequency power source to the thawing cavity;

[0020] A reflected power detection module is used to detect the electromagnetic wave power Pref1 reflected back from the thawing cavity;

[0021] A temperature detection module is used to detect the temperature of the object to be thawed;

[0022] The storage module is used to store the correspondence between the temperature of the object to be thawed and the thawing frequency, and the weight of the object to be thawed; it is also used to store the correspondence between the S-parameter of the thawing frequency and the fat content of the object to be thawed.

[0023] The control module is used to: acquire the initial thawing temperature of the object to be thawed through the temperature detection module; control the radio frequency power source to adjust the thawing frequency within a fixed frequency range by increasing or decreasing it according to a set time interval and a set step size, acquire Pin and Pref1 for each thawing frequency, calculate the electromagnetic wave absorption efficiency of the corresponding thawing frequency based on Pin and Pref1, and obtain the thawing frequency with the optimal electromagnetic wave absorption efficiency; determine the weight of the object to be thawed based on the initial thawing temperature and the thawing frequency with the optimal electromagnetic wave absorption efficiency; calculate S-parameters based on Pin and Pref1 of the thawing frequency with the optimal electromagnetic wave absorption efficiency, and determine the fat content of the object to be thawed based on the S-parameters; and determine a thawing strategy based on the initial thawing temperature, weight, and fat content of the object to be thawed, and perform thawing control according to the thawing strategy.

[0024] In the thawing device described above, the control module is used to determine the thawing time based on the initial thawing temperature, weight, fat content, electromagnetic wave power (Pin), and optimal electromagnetic wave absorption efficiency of the substance to be thawed.

[0025] In the thawing device described above, the thawing time = (initial thawing temperature + target temperature) * weight of the object to be thawed * specific heat capacity of the object to be thawed / (optimal electromagnetic wave absorption efficiency * Pin), wherein the specific heat capacity of the object to be thawed is determined by the fat content of the object to be thawed.

[0026] The defrosting device described above has a defrosting frequency of 450MHz ± 50MHz.

[0027] In the defrosting device described above, the set time interval is 1-3ms and the set step size is 0.5-2MHz.

[0028] In the thawing device described above, the S-parameter is S11 = a * log(Pref1 / Pin), where a is a coefficient.

[0029] As described above, the defrosting device includes a grounding terminal, a feeding terminal, and a vibrator, wherein both the grounding terminal and the feeding terminal have bent portions.

[0030] In the thawing device described above, the thawing chamber is a metal chamber.

[0031] In the defrosting device described above, the defrosting antenna is located on the bottom surface of the defrosting chamber, and a food tray is provided above the defrosting antenna.

[0032] A thawing method, the method being:

[0033] Detect the initial thawing temperature of the substance to be thawed;

[0034] The radio frequency power source is controlled to adjust the unfreezing frequency within a fixed frequency range by increasing or decreasing according to a set time interval and a set step size.

[0035] Obtain the electromagnetic wave power Pin transmitted from the radio frequency power source to the thawing cavity and the electromagnetic wave power Pref1 reflected back from the thawing cavity for each thawing frequency, and calculate the electromagnetic wave absorption efficiency for the corresponding thawing frequency based on Pin and Pref1.

[0036] The optimal electromagnetic wave absorption efficiency is obtained by considering all electromagnetic wave absorption efficiencies, and the thawing frequency at which the optimal electromagnetic wave absorption efficiency is located is obtained.

[0037] The relationship between the temperature of the object to be thawed and the thawing frequency and the weight of the object to be thawed is obtained, and the weight of the object to be thawed is obtained based on the initial thawing temperature and the thawing frequency at which the optimal electromagnetic wave absorption efficiency is located.

[0038] Calculate the S-parameters based on the thawing frequency Pin and Pref1 where the optimal electromagnetic wave absorption efficiency is located, and determine the fat content of the substance to be thawed based on the S-parameters.

[0039] The thawing strategy is determined based on the initial thawing temperature, weight, and fat content of the substance to be thawed, and thawing control is carried out according to the thawing strategy.

[0040] A refrigerator comprising the above-described defrosting device.

[0041] Compared with existing technologies, the advantages and positive effects of this invention are as follows: The thawing device of this invention includes a thawing chamber, a thawing antenna, a radio frequency power source, an incident power detection module, a reflected power detection module, a temperature detection module, a storage module, and a control module. The thawing chamber is used to contain the object to be thawed. The thawing antenna is located within the thawing chamber. The radio frequency power source is used to generate radio frequency signals within a fixed frequency range and transmit them through the thawing antenna. The incident power detection module is used to detect the electromagnetic wave power Pin transmitted from the radio frequency power source to the thawing chamber. The reflected power detection module is used to detect the electromagnetic wave power Pref1 reflected back from the thawing chamber. The temperature detection module is used to detect the temperature of the object to be thawed. The storage module is used to store the correspondence between the temperature of the object to be thawed and the thawing frequency, the weight of the object to be thawed, and the correspondence between the S-parameters of the thawing frequency and the fat content of the object to be thawed. The control module is used to obtain the initial thawing temperature of the object to be thawed through the temperature detection module; to control the radio frequency power source to increase or decrease the thawing frequency within a fixed frequency range according to a set time interval and a set step size, to obtain the Pin and Pref1 of each thawing frequency, to calculate the electromagnetic wave absorption efficiency of the corresponding thawing frequency based on Pin and Pref1, and to obtain the thawing frequency with the optimal electromagnetic wave absorption efficiency; to determine the weight of the object to be thawed based on the initial thawing temperature and the thawing frequency with the optimal electromagnetic wave absorption efficiency; to calculate the S-parameters based on Pin and Pref1 of the thawing frequency with the optimal electromagnetic wave absorption efficiency, and to determine the fat content of the object to be thawed based on the S-parameters; and to determine the thawing strategy based on the initial thawing temperature, weight, and fat content of the object to be thawed, and to perform thawing control according to the thawing strategy. This invention's thawing device automatically determines the weight of the substance to be thawed based on its initial thawing temperature and the thawing frequency where the optimal electromagnetic wave absorption efficiency is located. It calculates S-parameters based on Pin and Pref1 of the thawing frequency where the optimal electromagnetic wave absorption efficiency is located, determines the fat content of the substance based on the S-parameters of the thawing frequency where the optimal electromagnetic wave absorption efficiency is located, and determines the thawing strategy based on the initial thawing temperature, weight, and fat content of the substance. This invention ensures that the thawing strategy is applicable to substances of various compositions, guarantees the thawing effect, ensures that the degree of thawing meets user requirements, and ensures that the quality of the substance is not affected by the thawing process.

[0042] This invention's thawing method automatically determines the weight of the substance to be thawed based on its initial thawing temperature and the thawing frequency where the optimal electromagnetic wave absorption efficiency is located. It calculates S-parameters based on Pin and Pref1 of the thawing frequency where the optimal electromagnetic wave absorption efficiency is located, determines the fat content of the substance based on the S-parameters of the thawing frequency where the optimal electromagnetic wave absorption efficiency is located, and determines the thawing strategy based on the initial thawing temperature, weight, and fat content of the substance. This invention ensures that the thawing strategy is applicable to substances of various compositions, guarantees the thawing effect, ensures that the degree of thawing meets user requirements, and ensures that the quality of the substance is not affected by the thawing process.

[0043] Other features and advantages of the present invention will become clearer after reading the detailed embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a schematic diagram of the thawing device according to a specific embodiment of the present invention.

[0046] Figure 2 This is a schematic diagram of the defrosting device according to a specific embodiment of the present invention.

[0047] Figure 3 This is a schematic diagram of an antenna according to a specific embodiment of the present invention.

[0048] Figure 4 This is a flowchart of a thawing method according to a specific embodiment of the present invention. Detailed Implementation

[0049] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0050] It should be noted that in the description of this invention, terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," indicating directional or positional relationships, are based on the directional or positional relationships shown in the accompanying drawings. These are merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0051] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0052] This embodiment proposes a defrosting device using electromagnetic wave defrosting. Specifically, it determines the optimal defrosting strategy by detecting the initial defrosting temperature, weight, and fat content of the object to be defrosted. This embodiment automatically determines the weight of the object to be defrosted based on its initial defrosting temperature and the defrosting frequency where the optimal electromagnetic wave absorption efficiency is located. It calculates S-parameters based on the pin and pref1 of the defrosting frequency where the optimal electromagnetic wave absorption efficiency is located. It determines the fat content of the object to be defrosted based on the S-parameters of the defrosting frequency where the optimal electromagnetic wave absorption efficiency is located. Finally, it determines the defrosting strategy based on the initial defrosting temperature, weight, and fat content of the object, ensuring that the defrosting strategy is applicable to various types of objects to be defrosted, guaranteeing the defrosting effect, ensuring that the degree of defrosting meets user requirements, and ensuring that the quality of the object to be defrosted is not affected by the defrosting process.

[0053] like Figure 1 , 2 As shown, the defrosting device in this embodiment includes a defrosting chamber 5, a door 8, a food tray 4, a defrosting antenna 6, a PA component 1, a control module 2, a regulated power supply 3, an RF cable 7, a power cable 9, a signal control cable 10, and a temperature detection module 11.

[0054] The thawing chamber 5 is used to hold the items to be thawed.

[0055] The thawing chamber 5 is a metal chamber, preferably made of all-metal stainless steel, to prevent electromagnetic wave leakage; the inner cavity is smooth and flat, and the joints and corners are smooth and rounded to avoid electromagnetic wave accumulation and arcing.

[0056] Door 8 is used to seal the thawing chamber 5. Door 8 and thawing chamber 5 adopt an elastic sealing structure to compensate for electromagnetic leakage that may be caused by machining errors and assembly errors of door 8 and thawing chamber 5.

[0057] Generally, a food tray 4 is provided inside the thawing chamber 5. The food tray 4 is used to hold food, and the food to be thawed is placed on the food tray 4.

[0058] Food tray 4 is made of polyethylene.

[0059] The thawing antenna 6 is located inside the thawing cavity 5 and is used to emit electromagnetic waves to radiate the energy generated by the radio frequency power source into the thawing cavity 5.

[0060] The defrosting antenna 6 is located on the bottom surface of the defrosting chamber 5, and the food tray 4 is positioned above the defrosting antenna 6. That is, the defrosting antenna 6 is located between the defrosting chamber 5 and the food tray 4.

[0061] Since the thawing antenna 6 generally has a certain height, the height of the thawing device must be greater than the sum of the height of the space containing the object to be thawed and the height of the thawing antenna 6. Therefore, the height of the thawing antenna 6 affects the height of the thawing device. Simultaneously, the performance of the thawing antenna 6 is height-dependent; the higher the antenna, the better its matching characteristics. Therefore, the structural design of the thawing antenna 6 requires consideration of both spacing / height and performance.

[0062] To achieve a miniaturized design of the defrosting device while maintaining the performance of the defrosting antenna 6, such as Figure 3 As shown, this embodiment features a special design for the structure of the defrosting antenna 6:

[0063] The defrosting antenna 6 includes a grounding terminal 61, a feeding terminal 62, and an element 63. The element 63 is connected to the grounding terminal 61 and the feeding terminal 62. In this embodiment, both the grounding terminal 61 and the feeding terminal 62 have bent portions to reduce the height of the defrosting antenna 6.

[0064] The defrosting antenna 6 used in this embodiment adopts a bent structure, which greatly reduces the height of the defrosting antenna 6 while ensuring antenna performance, thereby helping to reduce the overall height of the defrosting device.

[0065] The antenna structure of this embodiment can operate efficiently in a thawing cavity 5 with a height of less than 200 mm.

[0066] Specifically, in this embodiment, the grounding terminal 61 has a first grounding bend 611 and a second grounding bend 612, and the power supply terminal 62 has a first power supply bend 621 and a second power supply bend 622. The design idea of ​​the bend is to reduce the height of the vibrator 63, but still ensure that the vibrator 63 has a certain height.

[0067] Preferably, the bending angle of the bent portion is 90 degrees.

[0068] In this embodiment, the portion between the first grounding bend 611 and the second grounding bend 612 is at a certain distance from the food tray 4, and the portion between the first power supply bend 621 and the second power supply bend 622 is at a certain distance from the food tray 4, which can avoid strong coupling with the food tray 4 or the food and generate local hot spots.

[0069] PA component 1, control module 2 and regulated power supply 3 are all located at the rear of the defrosting chamber 5. The regulated power supply 3 supplies power to the control module 2 and PA component 1 through power cable 9. PA component 1 is connected to defrosting antenna 6 through radio frequency cable 7. Control module 2 is connected to PA component 1 and temperature detection module 11 through signal control cable 10.

[0070] PA component 1 includes an RF power source, an incident power detection module, and a reflected power detection module.

[0071] The radio frequency power source is a signal source for generating the defrosting signal. It is used to generate radio frequency signals within a fixed frequency range and transmit them through the defrosting antenna 6.

[0072] The radio frequency power source is used to generate electromagnetic wave energy at a defrosting frequency of 450MHz±50MHz.

[0073] The electromagnetic wave energy of 450MHz±50MHz has good penetrability to food, and can heat the inside and outside of the food at the same time and evenly to achieve uniform thawing.

[0074] This embodiment uses an electromagnetic wave power source between 100-200W to ensure that food weighing ≤1.5kg can be thawed within 20 minutes, thus ensuring short thawing time and no juice loss.

[0075] Currently, industrial applications typically use frequency bands of 13MHz, 27MHz, 40MHz, 433MHz, 915MHz, and 2450MHz for food heating. Generally speaking, 13MHz, 27MHz, and 40MHz are more suitable for industrial scenarios because their frequencies are relatively low, resulting in low electromagnetic energy utilization and requiring greater power to defrost food.

[0076] The following examples show the penetration depth of electromagnetic waves at different frequencies (430MHz, 915MHz, and 2450MHz) into food:

[0077] Ingredients 450MHz 900MHz 2450MHz raw pork 4.7 cm 2.2 cm 0.8 cm raw beef 4.9 cm 2.3 cm 0.9 cm Cooked beef 6.5 cm 3.1 cm 1.2 cm cod 6.9 cm 3.3 cm 1.2 cm Mashed potatoes 4.0 cm 1.9 cm 0.7 cm carrot 5.2 cm 2.5 cm 0.9 cm

[0078] As can be seen from the table above, among 430MHz, 900MHz, and 2450MHz, the 430MHz penetration depth is more suitable for thawing foods weighing up to 5kg.

[0079] The incident power detection module is used to detect the electromagnetic wave power Pin transmitted from the radio frequency power source to the thawing cavity.

[0080] The reflected power detection module is used to detect the electromagnetic wave power Pref1 reflected back from the thawing cavity.

[0081] The temperature detection module is used to detect the temperature of the object to be thawed.

[0082] In this embodiment, the temperature detection module 11 is located at the top of the thawing chamber 5. It is an infrared temperature measurement module used to detect the surface temperature of the food to be thawed and take the lowest surface temperature at the start of thawing as the initial thawing temperature.

[0083] The control module also includes a storage module.

[0084] The storage module is used to store the correspondence between the temperature of the object to be thawed and the thawing frequency, and the weight of the object to be thawed; it is also used to store the correspondence between the S-parameters of the thawing frequency and the fat content of the object to be thawed.

[0085] The correspondence is determined beforehand through experiments and can be either a functional relationship or a correspondence table. Functional relationships offer more precise control, while correspondence tables provide a coarser control. The parameters in the correspondence table can be specific numerical values ​​or numerical ranges.

[0086] The control module is used to obtain the initial thawing temperature of the object to be thawed through the temperature detection module.

[0087] The control module is used to control the radio frequency power source to adjust the defrosting frequency within a fixed frequency range by increasing or decreasing according to a set time interval and a set step size. It obtains the Pin and Pref1 of each defrosting frequency, calculates the electromagnetic wave absorption efficiency of the corresponding defrosting frequency based on Pin and Pref1, and obtains the defrosting frequency with the best electromagnetic wave absorption efficiency.

[0088] Electromagnetic wave absorption efficiency = (Pin - Pref1) / Pin.

[0089] The time interval is set to 1-3ms, and the step size is set to 0.5-2MHz.

[0090] The control module is used to determine the weight of the object to be thawed based on the initial thawing temperature and the thawing frequency at which the optimal electromagnetic wave absorption efficiency is located.

[0091] The control module is used to calculate the S-parameters based on the thawing frequency Pin and Pref1 where the optimal electromagnetic wave absorption efficiency is located, and to determine the fat content of the substance to be thawed based on the S-parameters.

[0092] The S-parameter is S11 = a * log(Pref1 / Pin), where a is a coefficient, preferably any value between 8 and 12.

[0093] The control module is used to determine the thawing strategy based on the initial thawing temperature, weight, and fat content of the substance to be thawed, and to control the thawing process according to the thawing strategy.

[0094] Specifically, the control module is used to determine the thawing time based on the initial thawing temperature, weight, fat content, electromagnetic wave power Pin of the thawing chamber, and optimal electromagnetic wave absorption efficiency of the substance to be thawed.

[0095] Furthermore, the thawing time = (initial thawing temperature + target temperature) * weight of the object to be thawed * specific heat capacity of the object to be thawed / (optimal electromagnetic wave absorption efficiency * Pin), where the specific heat capacity of the object to be thawed is determined by the fat content of the object.

[0096] The experimental results comparing the same substance to be thawed using different methods are as follows:

[0097] Thawing method Thawing time Temperature difference (°C) Color change Blood / sap seepage Optimal temperature for stopping thawing Thaw naturally 4 hours 25 The surface layer, about 2mm deep, is somewhat whitish. More none Thawing by soaking in water 2 hours 25 The surface layer, about 10mm deep, will definitely turn white. a lot of none Refrigerate to thaw 12 hours 1 No obvious whitening less have Microwave defrosting (Model 1) 10 minutes 40 Large areas of severe whitening More none Microwave defrosting (Model 2) 15 minutes 55 Large areas of severe whitening More none This embodiment 15 minutes 3 none none have

[0098] like Figure 4 As shown, the defrosting method of the defrosting device is as follows:

[0099] S1, Begin.

[0100] Place the item to be thawed into the thawing chamber and receive the thawing start signal.

[0101] S2, the temperature detection module detects the temperature of the object to be thawed.

[0102] Preferably, the temperature detection module detects the surface temperature of the food to be thawed, and takes the lowest surface temperature as the initial thawing temperature.

[0103] S3. Control the RF power source to adjust the unfreezing frequency within a fixed frequency range by increasing or decreasing according to a set time interval and a set step size.

[0104] S4. Obtain Pin and Pref1 for each thawing frequency, and calculate the electromagnetic wave absorption efficiency for the corresponding thawing frequency based on Pin and Pref1.

[0105] Electromagnetic wave absorption efficiency = (Pin - Pref1) / Pin.

[0106] S5. Based on all electromagnetic wave absorption efficiencies, the optimal electromagnetic wave absorption efficiency is obtained, and then the thawing frequency at which the optimal electromagnetic wave absorption efficiency is located is obtained.

[0107] S6. Obtain the correspondence between the temperature of the object to be thawed, the thawing frequency, and the weight of the object to be thawed. Obtain the weight of the object to be thawed based on the initial thawing temperature and the thawing frequency at which the optimal electromagnetic wave absorption efficiency is located.

[0108] S7. Calculate the S-parameters based on the thawing frequency Pin and Pref1 where the optimal electromagnetic wave absorption efficiency is located.

[0109] The S-parameter is S11 = a * log(Pref1 / Pin), where a is a coefficient, preferably any value between 8 and 12.

[0110] S8. Determine the fat content of the substance to be thawed based on the S parameters.

[0111] S9. Determine the thawing strategy based on the initial thawing temperature, weight, and fat content of the substance to be thawed, and control the thawing process according to the thawing strategy.

[0112] Specifically, the control module is used to determine the thawing time based on the initial thawing temperature, weight, fat content, electromagnetic wave power Pin of the thawing chamber, and optimal electromagnetic wave absorption efficiency of the substance to be thawed.

[0113] Furthermore, the thawing time = (initial thawing temperature + target temperature) * weight of the object to be thawed * specific heat capacity of the object to be thawed / (optimal electromagnetic wave absorption efficiency * Pin), where the specific heat capacity of the object to be thawed is determined by the fat content of the object.

[0114] The target temperature is the temperature of the thawed item, typically -5 to 0℃.

[0115] This embodiment utilizes the excellent penetrability of 450MHz±50MHz electromagnetic waves to heat both internally and externally simultaneously. Electromagnetic radiation thawing enables uniform thawing of meat in a short time, ideally within a 20-minute period. For example, it can thaw up to 1.5kg of food within 20 minutes, with a temperature difference of less than ±2 degrees Celsius for 1kg of beef, offering safety and reliability. The antenna used achieves high-efficiency thawing within a small cavity, and its structure allows for efficient operation within cavities less than 200mm in height. This embodiment determines the weight of the food to be thawed based on the optimal efficiency frequency of the radio frequency electromagnetic waves, determines the composition (fat content percentage) of the food based on the S-parameters at the optimal efficiency point, determines the initial temperature of the food based on infrared thermometry, and determines a thawing strategy and automatically completes the thawing process based on the obtained parameters: weight, composition, and initial thawing temperature. The thawing strategy in this embodiment is determined based on the weight, composition, and initial thawing temperature of the object to be thawed. The thawing strategy is suitable for the object to be thawed, which can ensure that the thawing time is reduced and the thawing quality of the object is guaranteed. The temperature of the object to be thawed after thawing is determined in this embodiment to ensure that the object to be thawed is suitable for cutting.

[0116] This embodiment also proposes a refrigerator in which a defrosting device is embedded. The refrigerator includes a refrigerator compartment and / or a freezer compartment and a defrosting device.

[0117] The defrosting device includes a defrosting chamber 5, a door 8, a food tray 4, a defrosting antenna 6, a PA component 1, a control module 2, a regulated power supply 3, an RF cable 7, a power cable 9, a signal control cable 10, and a temperature detection module 11.

[0118] The thawing chamber 5 is used to hold the items to be thawed.

[0119] Door 8 is used to seal the thawing chamber 5. Door 8 and thawing chamber 5 adopt an elastic sealing structure to compensate for electromagnetic leakage that may be caused by machining errors and assembly errors of door 8 and thawing chamber 5.

[0120] Generally, a food tray 4 is provided inside the thawing chamber 5. The food tray 4 is used to hold food, and the food to be thawed is placed on the food tray 4.

[0121] Food tray 4 is made of polyethylene.

[0122] The thawing antenna 6 is located inside the thawing cavity 5 and is used to emit electromagnetic waves to radiate the energy generated by the radio frequency power source into the thawing cavity 5.

[0123] The defrosting antenna 6 is located on the bottom surface of the defrosting chamber 5, and the food tray 4 is positioned above the defrosting antenna 6. That is, the defrosting antenna 6 is located between the defrosting chamber 5 and the food tray 4.

[0124] Since the defrosting antenna 6 generally has a certain height, the height of the defrosting device must be greater than the sum of the height of the space containing the object to be defrosted and the height of the defrosting antenna 6. Therefore, the height of the defrosting antenna 6 will affect the height of the defrosting device. At the same time, the performance of the defrosting antenna 6 is related to its height. The higher the height, the better the matching characteristics of the defrosting antenna 6. Therefore, the structural design of the defrosting antenna 6 needs to meet both the requirements of spacing height and performance.

[0125] The defrosting antenna 6 includes a grounding terminal 61, a feeding terminal 62, and an element 63. The element 63 is connected to the grounding terminal 61 and the feeding terminal 62. In this embodiment, both the grounding terminal 61 and the feeding terminal 62 have bent portions to reduce the height of the defrosting antenna 6.

[0126] The defrosting antenna 6 used in this embodiment adopts a bent structure, which greatly reduces the height of the defrosting antenna 6 while ensuring antenna performance, thereby helping to reduce the overall height of the defrosting device.

[0127] PA component 1, control module 2 and regulated power supply 3 are all located at the rear of the defrosting chamber 5. The regulated power supply 3 supplies power to the control module 2 and PA component 1 through power cable 9. PA component 1 is connected to defrosting antenna 6 through radio frequency cable 7. Control module 2 is connected to PA component 1 and temperature detection module 11 through signal control cable 10.

[0128] PA component 1 includes an RF power source, an incident power detection module, and a reflected power detection module.

[0129] The radio frequency power source is a signal source for generating the defrosting signal. It is used to generate radio frequency signals within a fixed frequency range and transmit them through the defrosting antenna 6.

[0130] The radio frequency power source is used to generate electromagnetic wave energy at a defrosting frequency of 450MHz±50MHz.

[0131] The electromagnetic wave energy of 450MHz±50MHz has good penetrability to food, and can heat the inside and outside of the food at the same time and evenly to achieve uniform thawing.

[0132] This embodiment uses an electromagnetic wave power source between 100-200W to ensure that food weighing ≤1.5kg can be thawed within 20 minutes, thus ensuring short thawing time and no juice loss.

[0133] The incident power detection module is used to detect the electromagnetic wave power Pin transmitted from the radio frequency power source to the thawing cavity.

[0134] The reflected power detection module is used to detect the electromagnetic wave power Pref1 reflected back from the thawing cavity.

[0135] The temperature detection module is used to detect the temperature of the object to be thawed.

[0136] In this embodiment, the temperature detection module 11 is located at the top of the thawing chamber 5. It is an infrared temperature measurement module used to detect the surface temperature of the food to be thawed and take the lowest surface temperature as the initial thawing temperature.

[0137] The control module also includes a storage module.

[0138] The storage module is used to store the correspondence between the temperature of the object to be thawed and the thawing frequency, and the weight of the object to be thawed; it is also used to store the correspondence between the S-parameters of the thawing frequency and the fat content of the object to be thawed.

[0139] The correspondence is determined beforehand through experiments and can be either a functional relationship or a correspondence table. Functional relationships offer more precise control, while correspondence tables provide a coarser control. The parameters in the correspondence table can be specific numerical values ​​or numerical ranges.

[0140] The control module is used to obtain the initial thawing temperature of the object to be thawed through the temperature detection module.

[0141] The control module is used to control the radio frequency power source to adjust the defrosting frequency within a fixed frequency range by increasing or decreasing according to a set time interval and a set step size. It obtains the Pin and Pref1 of each defrosting frequency, calculates the electromagnetic wave absorption efficiency of the corresponding defrosting frequency based on Pin and Pref1, and obtains the defrosting frequency with the best electromagnetic wave absorption efficiency.

[0142] Electromagnetic wave absorption efficiency = (Pin - Pref1) / Pin.

[0143] The time interval is set to 1-3ms, and the step size is set to 0.5-2MHz.

[0144] The control module is used to determine the weight of the object to be thawed based on the initial thawing temperature and the thawing frequency at which the optimal electromagnetic wave absorption efficiency is located.

[0145] The control module is used to calculate the S-parameters based on the thawing frequency Pin and Pref1 where the optimal electromagnetic wave absorption efficiency is located, and to determine the fat content of the substance to be thawed based on the S-parameters.

[0146] The S-parameter is S11 = a * log(Pref1 / Pin), where a is a coefficient, preferably any value between 8 and 12.

[0147] The control module is used to determine the thawing strategy based on the initial thawing temperature, weight, and fat content of the substance to be thawed, and to control the thawing process according to the thawing strategy.

[0148] Specifically, the control module is used to determine the thawing time based on the initial thawing temperature, weight, fat content, electromagnetic wave power Pin of the thawing chamber, and optimal electromagnetic wave absorption efficiency of the substance to be thawed.

[0149] Furthermore, the thawing time = (initial thawing temperature + target temperature) * weight of the object to be thawed * specific heat capacity of the object to be thawed / (optimal electromagnetic wave absorption efficiency * Pin), where the specific heat capacity of the object to be thawed is determined by the fat content of the object.

[0150] The antenna structure of this embodiment can operate efficiently in a thawing cavity 5 with a height of less than 200 mm.

[0151] Specifically, in this embodiment, the grounding terminal 61 has a first grounding bend 611 and a second grounding bend 612, and the power supply terminal 62 has a first power supply bend 621 and a second power supply bend 622. The design idea of ​​the bend is to reduce the height of the vibrator 63, but still ensure that the vibrator 63 has a certain height.

[0152] Preferably, the bending angle of the bent portion is 90 degrees.

[0153] In this embodiment, the portion between the first grounding bend 611 and the second grounding bend 612 is at a certain distance from the food tray 4, and the portion between the first power supply bend 621 and the second power supply bend 622 is at a certain distance from the food tray 4, which can avoid strong coupling with the food tray 4 or the food and generate local hot spots.

[0154] Therefore, this embodiment can minimize the space occupied by the defrosting device while still achieving the desired defrosting effect, thus avoiding excessive space occupation in the refrigerator.

[0155] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions claimed by the present invention.

Claims

1. A defrosting device, comprising: The thawing chamber is used to hold the items to be thawed. The thawing antenna is located inside the thawing cavity; A radio frequency power source is used to generate radio frequency signals within a fixed frequency range and transmit them through the defrosting antenna; The device is characterized in that it comprises: An incident power detection module is used to detect the electromagnetic wave power Pin transmitted from the radio frequency power source to the thawing cavity; A reflected power detection module is used to detect the electromagnetic wave power Pref1 reflected back from the thawing cavity; A temperature detection module is used to detect the temperature of the object to be thawed; The storage module is used to store the correspondence between the temperature of the object to be thawed and the thawing frequency, and the weight of the object to be thawed; it is also used to store the correspondence between the S-parameter of the thawing frequency and the fat content of the object to be thawed. The control module is used to: acquire the initial thawing temperature of the object to be thawed through the temperature detection module; control the radio frequency power source to adjust the thawing frequency within a fixed frequency range by increasing or decreasing it according to a set time interval and a set step size, acquire Pin and Pref1 for each thawing frequency, calculate the electromagnetic wave absorption efficiency of the corresponding thawing frequency based on Pin and Pref1, and obtain the thawing frequency with the optimal electromagnetic wave absorption efficiency; determine the weight of the object to be thawed based on the initial thawing temperature and the thawing frequency with the optimal electromagnetic wave absorption efficiency; calculate S-parameters based on Pin and Pref1 of the thawing frequency with the optimal electromagnetic wave absorption efficiency, and determine the fat content of the object to be thawed based on the S-parameters; and determine a thawing strategy based on the initial thawing temperature, weight, and fat content of the object to be thawed, and perform thawing control according to the thawing strategy.

2. The defrosting device according to claim 1, characterized in that, The control module is used to determine the thawing time based on the initial thawing temperature, weight, fat content, electromagnetic wave power (Pin), and optimal electromagnetic wave absorption efficiency of the substance to be thawed.

3. The defrosting device according to claim 2, characterized in that, The thawing time = (initial thawing temperature + target temperature) * weight of the object to be thawed * specific heat capacity of the object to be thawed / (optimal electromagnetic wave absorption efficiency * Pin), wherein the specific heat capacity of the object to be thawed is determined by the fat content of the object to be thawed.

4. The defrosting device according to claim 1, characterized in that, The defrosting frequency is 450MHz±50MHz; the set time interval is 1-3ms; and the set step size is 0.5-2MHz.

5. The defrosting device according to claim 1, characterized in that, The S-parameter is S11 = a * log(Pref1 / Pin), where a is a coefficient.

6. The defrosting device according to claim 1, characterized in that, The defrosting antenna includes a grounding terminal, a feeding terminal, and a vibrator, and both the grounding terminal and the feeding terminal have bent portions.

7. The defrosting device according to claim 1, characterized in that, The thawing chamber is a metal chamber.

8. The defrosting device according to claim 1, characterized in that, The defrosting antenna is located on the bottom surface of the defrosting cavity, and a food tray is provided above the defrosting antenna.

9. A thawing method, the method comprising: Detect the initial thawing temperature of the substance to be thawed; The radio frequency power source is controlled to adjust the unfreezing frequency within a fixed frequency range by increasing or decreasing according to a set time interval and a set step size. Obtain the electromagnetic wave power Pin transmitted from the radio frequency power source to the thawing cavity and the electromagnetic wave power Pref1 reflected back from the thawing cavity for each thawing frequency, and calculate the electromagnetic wave absorption efficiency for the corresponding thawing frequency based on Pin and Pref1. The optimal electromagnetic wave absorption efficiency is obtained by considering all electromagnetic wave absorption efficiencies, and the thawing frequency at which the optimal electromagnetic wave absorption efficiency is located is obtained. The relationship between the temperature of the object to be thawed and the thawing frequency and the weight of the object to be thawed is obtained, and the weight of the object to be thawed is obtained based on the initial thawing temperature and the thawing frequency at which the optimal electromagnetic wave absorption efficiency is located. Calculate the S-parameters based on the thawing frequency Pin and Pref1 where the optimal electromagnetic wave absorption efficiency is located, and determine the fat content of the substance to be thawed based on the S-parameters. The thawing strategy is determined based on the initial thawing temperature, weight, and fat content of the substance to be thawed, and thawing control is carried out according to the thawing strategy.

10. A refrigerator, characterized in that, The refrigerator includes the defrosting device according to any one of claims 1-8.

Images