Unfreezing control method and device and refrigerator

Abstract

The invention discloses an unfreezing control method and device and a refrigerator, and the method comprises the steps: detecting the weight, the type, the real-time impedance and the real-time surface temperature of meat to be unfrozen, and recording the initial impedance; determining the target impedance of the thawing end point through the type and the initial impedance; determining an impedance difference value between the impedance at the current moment and the target impedance, if the difference value is greater than 0, entering an unfreezing process until the difference value is less than or equal to 0, and indicating that unfreezing is completed; the unfreezing process comprises the following steps: determining the standard unfreezing power at the current moment according to the weight, the type and the impedance difference value; determining whether the surface temperature at the current moment exceeds a critical temperature; if the temperature does not exceed the critical temperature, unfreezing at standard unfreezing power; and if the surface temperature exceeds the critical temperature, determining a calibration thawing power according to a temperature difference value between the surface temperature and the critical temperature in combination with a standard thawing power, and performing thawing with the calibration thawing power. According to the invention, intelligent unfreezing of different frozen foods can be realized, the unfreezing efficiency and uniformity are improved, and the unfreezing quality is ensured.

Description

Technical Field

[0001] This invention relates to the field of thawing technology, specifically to a thawing control method, device, and refrigerator. Background Technology

[0002] In modern households, the safe and efficient thawing of frozen meat is a critical technical challenge that urgently needs to be addressed. Currently, traditional thawing methods mainly include natural thawing, refrigerated thawing, and microwave thawing.

[0003] While natural thawing and refrigerated thawing can avoid localized overheating, they are slow processes that can lead to bacterial growth, especially when the surface temperature of meat is in the "danger zone" (4°C–6°C), where microorganisms multiply rapidly, posing a food safety risk. Furthermore, the long thawing time of these two methods makes it difficult for users to accurately predict the thawing completion time, impacting ease of use.

[0004] Microwave defrosting is a rapid defrosting method that uses electromagnetic waves to excite water molecules to vibrate and generate heat, thus achieving rapid warming. However, microwave heating has selectivity and limited penetration depth, leading to uneven defrosting and a tendency for the outside to be hot while the inside is cold. Especially for meats with uneven shapes or thicknesses, microwave energy may concentrate on the fat or edges, causing localized overheating and even partial tissue denaturation, affecting food quality.

[0005] In addition, the defrosting function in some existing refrigerator products often uses fixed power heating or timed defrosting, lacking a real-time monitoring and feedback control mechanism for the state of meat. It cannot dynamically adjust the defrosting strategy according to parameters such as the type, thickness, and temperature of the meat, resulting in poor defrosting effect, serious loss of juice, and affecting taste and nutritional value.

[0006] In recent years, some studies have attempted to introduce sensor technology to improve the thawing process. For example, infrared temperature sensors are used to monitor surface temperature and prevent overheating; or weight sensors are used to determine the thawing progress. However, these methods still lack accurate means of judging the internal state of the meat, making it difficult to achieve truly "intelligent thawing."

[0007] It is evident that the aforementioned existing thawing technologies each have their own applicable scope and limitations, and possess numerous problems, which can be summarized as follows: 1. "One-size-fits-all" thawing: Using the same time or power for all types, shapes, and sizes of meat results in thin edges or fatty parts being overheated while thicker parts are not fully thawed. 2. Difficulty in determining the thawing endpoint: Users find it difficult to accurately determine whether the meat has reached the ideal thawing state (usually -2°C to 0°C), and it is very easy to over-thaw, resulting in the proliferation of surface microorganisms and loss of juices. 3. Poor thawing uniformity: Microwave thawing is prone to causing local overheating, while traditional refrigeration thawing is too slow.

[0008] The aforementioned problems make it difficult for existing technologies to achieve precise control over the thawing process, affecting the safety, taste, and nutritional content of food. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides a defrosting control method, device, and refrigerator to achieve intelligent defrosting of different frozen foods, accurately determine the defrosting endpoint, improve defrosting efficiency and uniformity, and ensure the quality of defrosted food.

[0010] The present invention adopts the following technical solution.

[0011] According to a first aspect of the present invention, a thawing control method is provided. The method includes the following steps: The weight, type, real-time impedance, and real-time surface temperature of the meat to be thawed are detected, and the initial impedance is recorded. The target impedance at the thawing endpoint is determined by the type and initial impedance described above; Determine the impedance difference between the current impedance and the target impedance. If the impedance difference is greater than 0, proceed with the unfreezing process until the impedance difference is less than or equal to 0, indicating that unfreezing is complete. The unfreezing process includes: The standard thawing power at the current moment is determined based on the weight, the type, and the impedance difference. Determine whether the surface temperature at the current moment exceeds the critical temperature; if it does not exceed the critical temperature, then thaw using the standard thawing power; if it exceeds the critical temperature, then determine the calibrated thawing power based on the temperature difference between the surface temperature and the critical temperature, combined with the standard thawing power, and thaw using the calibrated thawing power, wherein the calibrated thawing power is lower than the standard thawing power.

[0012] In a further preferred embodiment, determining the impedance difference between the current impedance and the target impedance, and if the impedance difference is greater than 0, proceeding to the unfreezing process until the impedance difference is less than or equal to 0, indicating that unfreezing is complete, includes: After the thawing is complete, maintain the surface temperature of the thawed meat within the preset temperature range.

[0013] In a further preferred embodiment, determining the target impedance value of the thawing endpoint by the type includes: The target impedance is calculated using the following formula: Zg=K1·Z0 Where Zg is the target impedance; K1 is the proportionality coefficient, which is determined according to the type of meat to be thawed; and Z0 is the initial impedance.

[0014] In a further preferred embodiment, determining the standard thawing power at the current moment based on the weight, the type, and the impedance difference includes: The power attenuation coefficient during the thawing process of the meat to be thawed is determined based on the weight and type. Based on the attenuation coefficient and the impedance difference, the standard thawing power at the current moment is determined.

[0015] In a further preferred embodiment, determining the power attenuation coefficient during the thawing process of the meat to be thawed based on the weight and type includes: The power attenuation coefficient is determined by the following formula: K2=C·(W / ρ)^(2 / 3) / η Wherein, K2 is the power attenuation coefficient; C is the comprehensive correction coefficient calibrated through experiments; W is the weight of the meat to be thawed; ρ is the density of the meat to be thawed, determined by the type of meat to be thawed; and η is the efficiency coefficient.

[0016] In a further preferred embodiment, determining the power attenuation coefficient during the thawing process of the meat to be thawed based on the weight and type includes: Within a time period Δt after the start of the thawing process, thawing is carried out at the maximum safe thawing power Pmax to obtain the impedance change curve over time. Based on this curve, the initial slope S0 of the impedance change is determined, and the attenuation coefficient K2 is determined by the formula K2=k'·(S0 / S'). Here, k' is the preset base coefficient, and S' is the reference slope. Both k' and S' are selected according to the weight and type of meat to be thawed.

[0017] In a further preferred embodiment, determining the standard thawing power at the current moment based on the attenuation coefficient and the impedance difference includes: The standard thawing power at the current moment is determined by the following formula: P = Pmax·(1-exp(-K2·ΔZ / Z0)) Wherein, P is the standard defrosting power at the current moment; Pmax is the maximum safe defrosting power set by the system; K2 is the power attenuation coefficient; ΔZ is the difference between the current impedance and the target impedance; and Z0 is the initial impedance of the meat to be defrosted.

[0018] In a further preferred embodiment, if the critical temperature is exceeded, determining a calibrated thawing power based on the temperature difference between the critical temperature and the surface temperature, combined with a standard thawing power, and performing thawing using the calibrated thawing power, includes: If the temperature difference is less than or equal to the first temperature threshold: the calibrated thawing power is set to 60%~80% of the standard thawing power; If the temperature difference is greater than the first temperature threshold and less than the second temperature threshold: the calibrated thawing power is set to 20%~50% of the standard thawing power; If the temperature difference is greater than or equal to the second temperature threshold: set the calibration defrosting power to 0 until the surface temperature drops back to the restart temperature, and then re-enter the defrosting process.

[0019] According to a second aspect of the present invention, a defrosting control device is provided. The device includes: The thawing compartment is used to store meat that is about to be thawed. A weight sensor, an impedance sensor, and a temperature sensor are installed in the thawing chamber to measure the weight, real-time impedance, and real-time surface temperature of the meat to be thawed, respectively. A type identification component is used to identify the type of meat to be thawed; A defrosting assembly, located in the defrosting chamber, is used to defrost meat to be defrosted; The controller, connected to various sensors, category recognition components, and defrosting components, is used for: Obtain the weight, type, real-time impedance, and real-time surface temperature of the meat to be thawed, and record the initial impedance; The target impedance at the thawing endpoint is determined by the aforementioned type; Determine the impedance difference between the current impedance and the target impedance. If the impedance difference is greater than 0, proceed with the unfreezing process until the impedance difference is less than or equal to 0, indicating that unfreezing is complete. The unfreezing process includes: The standard thawing power at the current moment is determined based on the weight, the type, and the impedance difference. Determine whether the current surface temperature exceeds the critical temperature; if it does not exceed the critical temperature, control the defrosting component to defrost at the standard defrosting power; if it exceeds the critical temperature, determine the calibrated defrosting power based on the temperature difference between the surface temperature and the critical temperature, combined with the standard defrosting power, and control the defrosting component to defrost at the calibrated defrosting power, wherein the calibrated defrosting power is lower than the standard defrosting power.

[0020] In a further preferred embodiment, the controller is also configured to: After the thawing is complete, maintain the surface temperature of the thawed meat within the preset temperature range.

[0021] In a further preferred embodiment, the controller is also configured to: The target impedance is calculated using the following formula: Zg=K1·Z0 Where Zg is the target impedance; K1 is the proportionality coefficient, which is determined according to the type of meat to be thawed; and Z0 is the initial impedance.

[0022] In a further preferred embodiment, the controller is also configured to: The power attenuation coefficient during the thawing process of the meat to be thawed is determined based on the weight and type. Based on the attenuation coefficient and the impedance difference, the standard thawing power at the current moment is determined.

[0023] In a further preferred embodiment, the controller is also configured to: The power attenuation coefficient is determined by the following formula: K2=C·(W / ρ)^(2 / 3) / η Wherein, K2 is the power attenuation coefficient; C is the comprehensive correction coefficient calibrated through experiments; W is the weight of the meat to be thawed; ρ is the density of the meat to be thawed, determined by the type of meat to be thawed; and η is the efficiency coefficient.

[0024] In a further preferred embodiment, the controller is also configured to: The standard thawing power at the current moment is determined by the following formula: P = Pmax·(1-exp(-K2·ΔZ / Z0)) Wherein, P is the standard defrosting power at the current moment; Pmax is the maximum safe defrosting power set by the system; K2 is the power attenuation coefficient; ΔZ is the impedance difference between the current impedance and the target impedance; and Z0 is the initial impedance of the meat to be defrosted.

[0025] In a further preferred embodiment, the controller is also configured to: If the temperature difference is less than or equal to the first temperature threshold: the calibrated thawing power is set to 60%~80% of the standard thawing power; If the temperature difference is greater than the first temperature threshold and less than the second temperature threshold: the calibrated thawing power is set to 20%~50% of the standard thawing power; If the temperature difference is greater than or equal to the second temperature threshold: set the calibration defrosting power to 0 until the surface temperature drops back to the restart temperature, and then re-enter the defrosting process.

[0026] According to a third aspect of the present invention, a refrigerator is provided. The refrigerator includes a defrosting control device as described in the first aspect of the invention.

[0027] The beneficial effects of this invention are that, compared with the prior art, 1. By detecting the weight, type, real-time impedance, and real-time surface temperature of the meat to be thawed, a target impedance is determined. Then, based on the impedance difference between the current impedance and the target impedance, as well as the weight and type, a standard thawing power is determined for the current moment. When the surface temperature does not exceed the critical temperature, thawing is performed using the standard thawing power. When the surface temperature exceeds the critical temperature, the standard thawing power is calibrated based on the surface temperature, ensuring that the calibrated thawing power is lower than the standard thawing power. This allows for dynamic adjustment of the radio frequency thawing power, enabling automatic power adjustment according to the thawing progress, avoiding uneven thawing and energy waste, improving thawing efficiency and uniformity, and effectively preventing localized overheating.

[0028] 2. During the thawing process, the thawing power is reduced in stages based on the temperature difference between the surface temperature and the critical temperature. Specifically, when the temperature difference is less than or equal to the first temperature threshold, the calibration power is set to 60%~80% of the standard thawing power; when the temperature difference is greater than the first temperature threshold but less than the second temperature threshold, the calibration power is set to 20%~50% of the standard thawing power; when the temperature difference is greater than or equal to the second temperature threshold, thawing is stopped until the surface temperature drops to the restart temperature before resuming the thawing process. By adjusting the power in stages, temperature changes can be made more stable, improving the stability of the thawing process and reducing the impact of sudden temperature rises and falls on the meat tissue.

[0029] 3. By determining the power attenuation coefficient based on the weight and type of meat, different power adjustments can be made to optimize the power output strategy, achieve personalized defrosting, and improve defrosting efficiency and uniformity.

[0030] 4. Once the thawing is complete, stop the active heating and maintain the temperature of the thawing chamber within the preset temperature range (e.g., between -1°C and 0°C). This facilitates cutting and prevents juice loss or microbial growth due to excessively high temperatures. Attached Figure Description

[0031] Figure 1 This is a schematic flowchart of a thawing control method according to an embodiment of the present invention; Figure 2 A detailed thawing control method is provided in one embodiment of the present invention; Figure 3 This invention provides a curve showing the change in impedance of meat during the thawing process as a function of the thawing state, according to an embodiment of the present invention. Figure 4 This is a schematic diagram of a defrosting device according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the defrosting space structure in a defrosting device according to an embodiment of the present invention; Figure 6 This is a schematic diagram of a refrigerator with the defrosting device provided in an embodiment of the present invention.

[0032] The above figures include the following reference numerals: 1. Housing; 2. Upper electrode plate; 3. Lower electrode plate; 4. Upper insulating partition; 5. Lower insulating partition; 6. Thawing space; 7. Temperature sensor; 8. Weight sensor; 9. Impedance sensor; 10. Thawing tray; 11. Item to be thawed; 001. Thawing device Detailed Implementation To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. The embodiments described in this application are merely some embodiments of this invention, and not all embodiments. Based on the spirit of this invention, other embodiments obtained by those skilled in the art without creative effort are all within the protection scope of this invention.

[0033] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0034] In the following description, the terms "first" and "second" are used merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first" and "second" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0035] In the following description, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are expressly listed, but may include other steps or units that are not expressly listed or that are inherent to such process, method, product, or apparatus.

[0036] In existing thawing technologies, meat is typically thawed using the same time or power, without differentiation based on its type, weight, or shape. Furthermore, it's difficult to determine whether the meat has reached the ideal thawed state. Additionally, thawing uniformity is poor, with significant differences in thawing degree between the surface and interior of the meat. These problems make precise control of the thawing process difficult, affecting food safety, taste, and nutritional content.

[0037] Therefore, the present invention provides a defrosting control method, device and refrigerator to achieve intelligent defrosting of different frozen foods, accurately determine the defrosting endpoint, improve defrosting efficiency and uniformity, and ensure the quality of defrosted food.

[0038] A first aspect of the present invention provides a thawing control method.

[0039] like Figure 1 As shown, in one embodiment, the method includes the following steps: Step 1: Detect the weight, type, real-time impedance, and real-time surface temperature of the meat to be thawed, and record the initial impedance.

[0040] The testing can begin in response to a user placing meat into the defrosting chamber and initiating the defrosting process.

[0041] Initial impedance refers to the impedance of the meat to be thawed before radio frequency thawing is enabled.

[0042] Weight can be obtained by weighing using a weight sensor. Type can be identified by a camera or determined based on user input. Impedance can be measured using a bioimpedance measurement device composed of electrodes. Temperature can be measured using an infrared temperature sensor.

[0043] Step 2: Determine the target impedance at the thawing endpoint based on the type and initial impedance.

[0044] When meat is completely thawed, the temperature inside and outside the meat tends to be the same, the ice crystals completely disappear, and it turns into liquid water. At this point, the impedance value reaches a low level and tends to stabilize. The target impedance is mainly affected by the type of meat, fat content, and final temperature, but no longer changes drastically due to the phase transition (ice → water).

[0045] Step 3: Determine the impedance difference between the current impedance and the target impedance. If the impedance difference is greater than 0, proceed with the unfreezing process until the impedance difference is less than or equal to 0, indicating that unfreezing is complete.

[0046] The thawing process includes the following steps: Step 31: Determine the standard thawing power at the current moment based on the weight, type, and impedance difference.

[0047] Step 32: Determine whether the surface temperature at the current moment exceeds the critical temperature; if it does not exceed the critical temperature, then thaw using the standard thawing power; if it exceeds the critical temperature, then determine the calibrated thawing power based on the temperature difference between the surface temperature and the critical temperature, combined with the standard thawing power, and thaw using the calibrated thawing power, wherein the calibrated thawing power is lower than the standard thawing power.

[0048] The critical temperature in this step can be, for example, 5°C. Above this critical temperature, the surface of the meat tends to dry out, affecting the quality of the thawed meat.

[0049] In this embodiment, the target impedance is determined by detecting the weight, type, real-time impedance, and real-time surface temperature of the meat to be thawed. Then, based on the impedance difference between the current impedance and the target impedance, as well as the weight and type, the standard thawing power for the current moment is determined. When the surface temperature does not exceed the critical temperature, thawing is performed using the standard thawing power. When the surface temperature exceeds the critical temperature, the standard thawing power is calibrated based on the surface temperature, ensuring that the calibrated thawing power is lower than the standard thawing power. This allows for dynamic adjustment of the radio frequency thawing power, enabling automatic power adjustment according to the thawing progress, avoiding uneven thawing and energy waste, improving thawing efficiency and uniformity, and effectively preventing localized overheating.

[0050] In a further preferred embodiment, step 2 includes: The target impedance is calculated using the following formula: Zg=K1·Z0 Where Zg is the target impedance; K1 is the proportionality coefficient, which is determined according to the type of meat to be thawed; and Z0 is the initial impedance.

[0051] Specifically, K1 is determined as follows: A database is established through experiments to find the ratio of the final impedance value (Zfinal) to the initial impedance value (Zinitial) when the core temperature reaches the ideal thawing endpoint temperature (e.g., -1℃) for various types of meat. This ratio yields the proportionality coefficient K1, expressed as: K1 = Zfinal / Zinitial As an example, for most meats, the K1 value is typically between 0.15 and 0.35, such as approximately 0.2 for beef.

[0052] In this embodiment, by solving for the target impedance value, it is possible to more accurately determine whether the meat has reached the ideal thawing state, thereby improving the quality of the thawed meat.

[0053] In a further preferred embodiment, step 31 includes: Step 311: Determine the power attenuation coefficient during the thawing process of the meat to be thawed based on the weight and type.

[0054] This step can be achieved in two ways.

[0055] Method 1: The power attenuation coefficient is determined by the following formula: K2=C·(W / ρ)^(2 / 3) / η Wherein, K2 is the power attenuation coefficient; C is the comprehensive correction coefficient calibrated through experiments; W is the weight of the meat to be thawed; ρ is the density of the meat to be thawed, determined by the type of meat to be thawed; and η is the efficiency coefficient.

[0056] Method 2: Within a time period Δt after the start of the thawing process, thawing is carried out at the maximum safe thawing power Pmax, and the impedance change curve over time is obtained. Based on this curve, the initial slope S0 of the impedance change is determined, and the power attenuation coefficient K2 is determined by the formula K2=k'·(S0 / S'). Here, k' is a preset basic coefficient, and S' is a reference slope. Both k' and S' are selected based on the weight and type of meat to be thawed and are empirical constant values.

[0057] For example, assuming Δt = 30s, the impedance value on the curve can be sampled every 1s during the time period from 0 to 30s, and the slope of the curve segment between t = 0 and t = 1s can be calculated as the initial slope S0 of the impedance change.

[0058] In this way, if S0 is large (for example, a thin slice of meat), the calculated power attenuation coefficient K2 will be large, resulting in rapid power attenuation and preventing overheating. If S0 is small (for example, a large piece of very solid frozen meat), the calculated power attenuation coefficient K2 will be small, resulting in slow power attenuation and ensuring sufficient energy to penetrate to the core.

[0059] Step 312: Based on the attenuation coefficient and the impedance difference, determine the standard thawing power at the current moment.

[0060] Specifically, this step may include: The standard thawing power at the current moment is determined by the following formula: P = Pmax·(1-exp(-K2·ΔZ / Z0)) Wherein, P is the standard defrosting power at the current moment; Pmax is the maximum safe defrosting power set by the system; K2 is the power attenuation coefficient; ΔZ is the impedance difference between the current impedance and the target impedance; and Z0 is the initial impedance of the meat to be defrosted.

[0061] In this step, by introducing an exponential function to solve for the standard thawing power, it is possible to achieve rapid thawing when ΔZ is large (corresponding to the initial stage of thawing) and standard thawing power P≈Pmax; while when ΔZ approaches 0 (corresponding to the final stage of thawing), standard thawing power P also approaches 0, thereby achieving a smooth transition in the thawing process and preventing inertial overheating from affecting the quality of the thawed food.

[0062] In a further preferred embodiment, step 32 includes: S321. If the temperature difference is less than or equal to the first temperature threshold: the calibrated defrosting power is set to 60%~80% of the standard defrosting power; S322. If the temperature difference is greater than the first temperature threshold and less than the second temperature threshold: set the calibrated defrosting power to 20%~50% of the standard defrosting power; S323. If the temperature difference is greater than or equal to the second temperature threshold: set the calibration defrosting power to 0 until the surface temperature drops back to the restart temperature, and then re-enter the defrosting process.

[0063] Preferably, in the above steps S321 to S323, the first temperature threshold can be set to 0.8℃ to 1.5℃, and the second temperature threshold can be set to 2.5℃ to 3.5℃.

[0064] As an example, if the surface temperature of the meat is Ts and the critical temperature is Tc (e.g., 5℃), then the temperature difference ΔT = Ts - Tc. Assuming the first temperature threshold is set to 1℃ and the second temperature threshold is set to 3℃, once ΔT ≥ 0, regardless of the difference ΔZ between the current impedance and the target impedance, the power will be reduced in stages according to ΔT = Ts - Tc. Specifically, when ΔT ≤ 1℃: the calibrated defrosting power will be set to 70% of the standard defrosting power; when 1℃ < ΔT < 3℃: the calibrated defrosting power will be set to 40% of the standard defrosting power; when ΔT ≥ 3℃: the calibrated defrosting power is set to 0, defrosting is paused, and the defrosting process will resume after the surface temperature drops to the restart temperature. This restart temperature can be, for example, set to the critical temperature Tc, or slightly below the critical temperature. In other words, when the surface temperature Ts drops below or below this restart temperature, steps S31 and S32 are executed again.

[0065] In this implementation, by adjusting the defrosting power in stages, the temperature changes can be made more stable, the stability of the defrosting process can be improved, and the impact of sudden temperature rises and falls on meat tissue can be reduced.

[0066] In a further preferred embodiment, step S3 further includes: after indicating that thawing is complete, maintaining the surface temperature of the thawed meat within a preset temperature range.

[0067] As an example, the preset temperature range can be set to -1℃ to 0℃. Preferably, an audible alert can be issued upon completion of the thawing process to notify the user that the meat is in optimal thawing condition and ready for use.

[0068] In this embodiment, after the thawing is completed, active heating is stopped, and the temperature of the thawing chamber is maintained within a preset temperature range (e.g., between -1°C and 0°C). This facilitates cutting and prevents juice loss or microbial growth due to excessively high temperatures.

[0069] In a further preferred embodiment, such as Figure 2As shown, the thawing control method of the present invention is as follows: Step 1: Detect the weight W, type, real-time impedance, and real-time surface temperature of the meat to be thawed, and record the initial impedance Z0.

[0070] Step 2: Determine the target impedance Zg at the thawing endpoint based on the type and initial impedance: Zg = K1·Z0.

[0071] Step 3: Determine the impedance difference ΔZ between the current impedance and the target impedance: ΔZ = Zt - Zg, where Zt is the impedance at the current time t; Step 4: If the impedance difference is greater than 0, then determine the standard thawing power P at the current moment based on the weight, the type, and the impedance difference. P = Pmax * (1 - exp(-k2 * ΔZ / Z0)) Where Pmax is the maximum safe thawing power; K2 is the power attenuation coefficient.

[0072] Step 5: Determine whether the surface temperature at the current moment exceeds the critical temperature, and calculate the temperature difference.

[0073] Step 6: If the surface temperature at the current moment does not exceed the critical temperature, then defrost using the standard defrosting power.

[0074] Step 7: If the surface temperature at the current moment exceeds the critical temperature, and the temperature difference is less than or equal to the first temperature threshold: set the calibrated defrosting power to 60%~80% of the standard defrosting power, and defrost using the calibrated defrosting power.

[0075] Step 8: If the surface temperature at the current moment exceeds the critical temperature, and the temperature difference is greater than the first temperature threshold and less than the second temperature threshold: set the calibration thawing power to 20%~50% of the standard thawing power, and thaw using the calibration thawing power.

[0076] Step 9: If the surface temperature at the current moment exceeds the critical temperature, and the temperature difference is greater than or equal to the second temperature threshold: set the calibration defrosting power to 0 until the surface temperature drops back to the restart temperature, and then re-enter the defrosting process.

[0077] Step 10: When the impedance difference ΔZ is less than or equal to 0, it indicates that thawing is complete. Maintain the surface temperature of the thawed meat within the preset temperature range (e.g., -1℃ to 0℃).

[0078] Figure 3 The graph shows the impedance variation with thawing state during meat thawing, obtained by the method of the present invention. This curve can be clearly divided into four typical stages, which perfectly correspond to the physical state of the meat: Phase I: Completely frozen zone (corresponding to the high impedance plateau period) ①State: The meat is in a deep-frozen state (e.g., -18℃), where almost all of its internal moisture is frozen into ice. Ice is a poor conductor of electricity and has extremely high impedance.

[0079] ② Curve characteristics: The impedance value remains at a high and stable level. During this stage, even if the temperature rises slightly, the impedance change is very small as long as the ice crystals do not melt in large quantities. Phase II: Rapid Surface Thawing Zone (corresponding to a period of sharp decrease in impedance) ① State: The thawing energy begins to rapidly melt the ice crystals on the surface of the meat. The presence of liquid water creates an ion-conducting pathway.

[0080] ② Curve characteristics: The impedance value drops sharply, and the curve is very steep. This is because the transformation from an insulator (ice) to a conductor (water) is a qualitative change, with a leap in conductivity. This stage corresponds to the initial stage of "the surface is completely thawed, but the inside is not." Phase III: Core Thawing Zone (corresponding to the period of slow impedance decrease) ① Status: At this point, the surface of the meat has completely thawed, forming a "thawing front" that gradually moves towards the core. The ice crystals in the core continue to melt.

[0081] ② Curve characteristics: The impedance continues to decrease, but the slope of the curve becomes gentler, showing a gradual downward trend. This is because: 1. Current can more easily pass through the thawed surface layer. 2. The melting of ice crystals in the core, although still increasing the conductive path, contributes less to the overall impedance compared to the "from nothing to something" process in Stage II.

[0082] Phase IV: Complete Unfreezing Region (Low Impedance Stable Region) ①State: The temperature inside and outside of the meat tends to be the same, the ice crystals completely disappear, and it turns into liquid water.

[0083] ② Curve characteristics: The impedance value reaches a low level and tends to stabilize. At this point, the impedance is mainly affected by the type of meat, fat content, and final temperature, but no longer changes drastically due to phase transition (ice → water).

[0084] As can be seen, the defrosting control method of the present invention can determine the power attenuation coefficient according to the weight and type of meat, and make different power adjustments in combination with the impedance difference between the current impedance and the target impedance and the temperature difference between the surface temperature and the critical temperature, optimize the power output strategy, realize personalized defrosting, and improve defrosting efficiency and uniformity.

[0085] A second aspect of the present invention provides a defrosting control device.

[0086] In one embodiment, such as Figure 4 and 5The defrosting control device 001 includes: a defrosting chamber, a weight sensor 8, an impedance sensor 9, a temperature sensor 7, a species identification component, a defrosting component, and a controller.

[0087] The thawing chamber is used to store meat to be thawed and includes a shell 1. Inside the shell 1, there is a thawing cavity, a thawing space 6 placed inside the thawing cavity, and a temperature sensor 7. The thawing space can be a pull-out drawer structure or a rectangular box-shaped structure, as long as it can accommodate the items to be thawed. This embodiment uses a drawer-type structure. A thawing tray 10 is provided at the bottom of the thawing space 6 for placing the items to be thawed.

[0088] Temperature sensor 7 is an infrared temperature sensor. Temperature sensor 7 can monitor the surface temperature of meat to be thawed in real time.

[0089] Impedance sensor 9 is made of stainless steel electrodes and is evenly arranged inside the defrosting tray for non-destructive measurement of the impedance value of meat.

[0090] The weight sensor 8 is located at the bottom of the defrosting tray 10 and is used to detect the weight of the items to be defrosted placed in the tray.

[0091] The type identification component may include a camera and a recognition unit, or a signal receiver. The camera and recognition unit can automatically identify the type of meat, while the signal receiver can be connected to the input device, either wirelessly or in a limited manner, to obtain the type of meat input by the user.

[0092] The defrosting assembly includes an upper electrode plate 2, a lower electrode plate 3, an upper insulating partition 4, and a lower insulating partition 5. The upper electrode plate 2 is located at the top of the inner wall of the housing 1, and the lower electrode plate 3 is located at the bottom of the inner wall of the housing 1. The upper electrode plate 1 and the lower electrode plate 2 are connected to a radio frequency (RF) power supply via a coaxial cable, thereby generating a high-frequency electric field to defrost the object 11. The RF power supply has variable power, which is adjusted by a controller according to the defrosting status. Furthermore, the upper insulating partition 4 is located below the upper electrode plate, and the lower insulating partition 5 is located above the lower electrode plate, thus isolating the defrosting chamber from the upper and lower electrode plates to prevent contact between the object and the electrode plates. During defrosting, the object 11 is placed in the defrosting space and defrosted using the high-frequency electric field.

[0093] The controller is connected to various sensors, category recognition components, and defrosting components for the following purposes: Obtain the weight, type, real-time impedance, and real-time surface temperature of the meat to be thawed, and record the initial impedance; The target impedance at the thawing endpoint is determined by the aforementioned type; Determine the impedance difference between the current impedance and the target impedance. If the impedance difference is greater than 0, proceed with the unfreezing process until the impedance difference is less than or equal to 0, indicating that unfreezing is complete. The unfreezing process includes: The standard thawing power at the current moment is determined based on the weight, the type, and the impedance difference. Determine whether the current surface temperature exceeds the critical temperature; if it does not exceed the critical temperature, control the defrosting component to defrost at the standard defrosting power; if it exceeds the critical temperature, determine the calibrated defrosting power based on the temperature difference between the surface temperature and the critical temperature, combined with the standard defrosting power, and control the defrosting component to defrost at the calibrated defrosting power, wherein the calibrated defrosting power is lower than the standard defrosting power.

[0094] In a further preferred embodiment, the controller is also configured to: After the thawing is complete, maintain the surface temperature of the thawed meat within the preset temperature range.

[0095] In a further preferred embodiment, the controller is also configured to: The target impedance is calculated using the following formula: Zg=K1·Z0 Where Zg is the target impedance; K1 is the proportionality coefficient, which is determined according to the type of meat to be thawed; and Z0 is the initial impedance.

[0096] In a further preferred embodiment, the controller is also configured to: The power attenuation coefficient during the thawing process of the meat to be thawed is determined based on the weight and type. Based on the attenuation coefficient and the impedance difference, the standard thawing power at the current moment is determined.

[0097] In a further preferred embodiment, the controller is also configured to: The power attenuation coefficient is determined by the following formula: K2=C·(W / ρ)^(2 / 3) / η Wherein, K2 is the power attenuation coefficient; C is the comprehensive correction coefficient calibrated through experiments; W is the weight of the meat to be thawed; ρ is the density of the meat to be thawed, determined by the type of meat to be thawed; and η is the efficiency coefficient.

[0098] In a further preferred embodiment, the controller is also configured to: The standard thawing power at the current moment is determined by the following formula: P = Pmax·(1-exp(-K2·ΔZ / Z0)) Wherein, P is the standard defrosting power at the current moment; Pmax is the maximum safe defrosting power set by the system; K2 is the power attenuation coefficient; ΔZ is the impedance difference between the current impedance and the target impedance; and Z0 is the initial impedance of the meat to be defrosted.

[0099] In a further preferred embodiment, the controller is also configured to: If the temperature difference is less than or equal to the first temperature threshold: the calibrated thawing power is set to 60%~80% of the standard thawing power; If the temperature difference is greater than the first temperature threshold and less than the second temperature threshold: the calibrated thawing power is set to 20%~50% of the standard thawing power; If the temperature difference is greater than or equal to the second temperature threshold: set the calibration defrosting power to 0 until the surface temperature drops back to the restart temperature, and then re-enter the defrosting process.

[0100] A third aspect of the present invention provides a refrigerator having the defrosting device of the present invention. Figure 6 This is a refrigerator according to one embodiment of the present invention. Specifically, the defrosting device of the present invention is disposed inside the refrigerator.

[0101] In summary, the beneficial effects of the present invention are that, compared with the prior art, 1. By detecting the weight, type, real-time impedance, and real-time surface temperature of the meat to be thawed, a target impedance is determined. Then, based on the impedance difference between the current impedance and the target impedance, as well as the weight and type, a standard thawing power is determined for the current moment. When the surface temperature does not exceed the critical temperature, thawing is performed using the standard thawing power. When the surface temperature exceeds the critical temperature, the standard thawing power is calibrated based on the surface temperature, ensuring that the calibrated thawing power is lower than the standard thawing power. This allows for dynamic adjustment of the radio frequency thawing power, enabling automatic power adjustment according to the thawing progress, avoiding uneven thawing and energy waste, improving thawing efficiency and uniformity, and effectively preventing localized overheating.

[0102] 2. During the thawing process, the thawing power is reduced in stages based on the temperature difference between the surface temperature and the critical temperature. Specifically, when the temperature difference is less than or equal to the first temperature threshold, the calibration power is set to 60%~80% of the standard thawing power; when the temperature difference is greater than the first temperature threshold but less than the second temperature threshold, the calibration power is set to 20%~50% of the standard thawing power; when the temperature difference is greater than or equal to the second temperature threshold, thawing is stopped until the surface temperature drops to the restart temperature before resuming the thawing process. By adjusting the power in stages, temperature changes can be made more stable, improving the stability of the thawing process and reducing the impact of sudden temperature rises and falls on the meat tissue.

[0103] 3. By determining the power attenuation coefficient based on the weight and type of meat, different power adjustments can be made to optimize the power output strategy, achieve personalized defrosting, and improve defrosting efficiency and uniformity.

[0104] 4. Once the thawing is complete, stop the active heating and maintain the temperature of the thawing chamber within the preset temperature range (e.g., between -1°C and 0°C). This facilitates cutting and prevents juice loss or microbial growth due to excessively high temperatures.

[0105] This disclosure can be a system, method, and / or computer program product. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of this disclosure.

[0106] Computer-readable storage media can be tangible devices capable of holding and storing instructions for use by an instruction execution device. Computer-readable storage media can be, for example—but not limited to—electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination of the foregoing. The computer-readable storage media used herein are not to be construed as transient signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses through fiber optic cables), or electrical signals transmitted through wires.

[0107] The computer-readable program instructions described herein can be downloaded from computer-readable storage media to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to the computer-readable storage media in the respective computing / processing device.

[0108] Computer program instructions used to perform the operations of this disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, status setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The computer-readable program instructions may execute entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), is personalized by utilizing the status information of the computer-readable program instructions to implement various aspects of this disclosure.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A thawing control method, characterized in that, Includes the following steps: The weight, type, real-time impedance, and real-time surface temperature of the meat to be thawed are detected, and the initial impedance is recorded. The target impedance at the thawing endpoint is determined by the type and initial impedance described above; Determine the impedance difference between the current impedance and the target impedance. If the impedance difference is greater than 0, proceed with the unfreezing process until the impedance difference is less than or equal to 0, indicating that unfreezing is complete. The thawing process includes: The standard thawing power at the current moment is determined based on the weight, the type, and the impedance difference. Determine whether the surface temperature at the current moment exceeds the critical temperature; if it does not exceed the critical temperature, then thaw using the standard thawing power; if it exceeds the critical temperature, then determine the calibrated thawing power based on the temperature difference between the surface temperature and the critical temperature, combined with the standard thawing power, and thaw using the calibrated thawing power, wherein the calibrated thawing power is lower than the standard thawing power.

2. The thawing control method according to claim 1, characterized in that, The process of determining the impedance difference between the current impedance and the target impedance, and proceeding to the unfreezing process if the difference is greater than 0, continues until the difference is less than or equal to 0, indicating that unfreezing is complete. This includes: After the thawing is complete, maintain the surface temperature of the thawed meat within the preset temperature range.

3. The thawing control method according to claim 1, characterized in that, The determination of the target impedance value at the thawing endpoint based on the aforementioned type includes: The target impedance is calculated using the following formula: Zg=K1·Z0 Where Zg is the target impedance; K1 is the proportionality coefficient, which is determined according to the type of meat to be thawed; and Z0 is the initial impedance.

4. The thawing control method according to claim 1, characterized in that, Determining the standard thawing power at the current moment based on the weight, the type, and the impedance difference includes: The power attenuation coefficient during the thawing process of the meat to be thawed is determined based on the weight and type. Based on the attenuation coefficient and the impedance difference, the standard thawing power at the current moment is determined.

5. The thawing control method according to claim 4, characterized in that, Determining the power attenuation coefficient during the thawing process of the meat to be thawed based on the weight and type includes: The power attenuation coefficient is determined by the following formula: K2=C·(W / ρ)^(2 / 3) / η Wherein, K2 is the power attenuation coefficient; C is the comprehensive correction coefficient calibrated through experiments; W is the weight of the meat to be thawed; ρ is the density of the meat to be thawed, determined by the type of meat to be thawed; and η is the efficiency coefficient.

6. The thawing control method according to claim 4, characterized in that, Determining the power attenuation coefficient during the thawing process of the meat to be thawed based on the weight and type includes: Within a time period Δt after the start of the thawing process, thawing is carried out at the maximum safe thawing power Pmax to obtain the impedance change curve over time. Based on this curve, the initial slope S0 of the impedance change is determined, and then the power attenuation coefficient K2 is determined by the formula K2=k'·(S0 / S'). Wherein, k' is the preset base coefficient, and S' is the reference slope. Both k' and S' are selected according to the weight and type of meat to be thawed.

7. The thawing control method according to claim 4, characterized in that, The determination of the standard thawing power at the current moment based on the attenuation coefficient and the impedance difference includes: The standard thawing power at the current moment is determined by the following formula: P = Pmax·(1-exp(-K2·ΔZ / Z0)) Wherein, P is the standard defrosting power at the current moment; Pmax is the maximum safe defrosting power set by the system; K2 is the power attenuation coefficient; ΔZ is the impedance difference between the current impedance and the target impedance; and Z0 is the initial impedance of the meat to be defrosted.

8. The thawing control method according to claim 4, characterized in that, If the critical temperature is exceeded, a calibrated thawing power is determined based on the temperature difference between the critical temperature and the surface temperature, combined with the standard thawing power, and thawing is performed using the calibrated thawing power, including: If the temperature difference is less than or equal to the first temperature threshold: the calibrated thawing power is set to 60%~80% of the standard thawing power; If the temperature difference is greater than the first temperature threshold and less than the second temperature threshold: the calibrated thawing power is set to 20%~50% of the standard thawing power; If the temperature difference is greater than or equal to the second temperature threshold: set the calibration defrosting power to 0 until the surface temperature drops back to the restart temperature, and then re-enter the defrosting process.

9. A defrosting control device, characterized in that, include: The thawing compartment is used to store meat that is about to be thawed. A weight sensor, an impedance sensor, and a temperature sensor are installed in the thawing chamber to measure the weight, real-time impedance, and real-time surface temperature of the meat to be thawed, respectively. A type identification component is used to identify the type of meat to be thawed; A defrosting assembly, located in the defrosting chamber, is used to defrost meat to be defrosted; The controller, connected to various sensors, category recognition components, and defrosting components, is used for: Obtain the weight, type, real-time impedance, and real-time surface temperature of the meat to be thawed, and record the initial impedance; The target impedance at the thawing endpoint is determined by the aforementioned type; Determine the impedance difference between the current impedance and the target impedance. If the impedance difference is greater than 0, proceed with the unfreezing process until the impedance difference is less than or equal to 0, indicating that unfreezing is complete. The thawing process includes: The standard thawing power at the current moment is determined based on the weight, the type, and the impedance difference. Determine whether the current surface temperature exceeds the critical temperature; if it does not exceed the critical temperature, control the defrosting component to defrost at the standard defrosting power; if it exceeds the critical temperature, determine the calibrated defrosting power based on the temperature difference between the surface temperature and the critical temperature, combined with the standard defrosting power, and control the defrosting component to defrost at the calibrated defrosting power, wherein the calibrated defrosting power is lower than the standard defrosting power.

10. The defrosting control device according to claim 9, characterized in that, The controller is also used for: After the thawing is complete, maintain the surface temperature of the thawed meat within the preset temperature range.

11. The thawing control method according to claim 9, characterized in that, The controller is also used for: The target impedance is calculated using the following formula: Zg=K1·Z0 Where Zg is the target impedance; K1 is the proportionality coefficient, which is determined according to the type of meat to be thawed; and Z0 is the initial impedance.

12. The thawing control method according to claim 9, characterized in that, The controller is also used for: The power attenuation coefficient during the thawing process of the meat to be thawed is determined based on the weight and type. Based on the attenuation coefficient and the impedance difference, the standard thawing power at the current moment is determined.

13. The thawing control method according to claim 9, characterized in that, The controller is also used for: The power attenuation coefficient is determined by the following formula: K2=C·(W / ρ)^(2 / 3) / η Wherein, K2 is the power attenuation coefficient; C is the comprehensive correction coefficient calibrated through experiments; W is the weight of the meat to be thawed; ρ is the density of the meat to be thawed, determined by the type of meat to be thawed; and η is the efficiency coefficient.

14. The thawing control method according to claim 9, characterized in that, The controller is also used for: The standard thawing power at the current moment is determined by the following formula: P = Pmax·(1-exp(-K2·ΔZ / Z0)) Wherein, P is the standard defrosting power at the current moment; Pmax is the maximum safe defrosting power set by the system; K2 is the power attenuation coefficient; ΔZ is the impedance difference between the current impedance and the target impedance; and Z0 is the initial impedance of the meat to be defrosted.

15. The thawing control method according to claim 9, characterized in that, The controller is also used for: If the temperature difference is less than or equal to the first temperature threshold: the calibrated thawing power is set to 60%~80% of the standard thawing power; If the temperature difference is greater than the first temperature threshold and less than the second temperature threshold: the calibrated thawing power is set to 20%~50% of the standard thawing power; If the temperature difference is greater than or equal to the second temperature threshold: set the calibration defrosting power to 0 until the surface temperature drops back to the restart temperature, and then re-enter the defrosting process.

16. A refrigerator, characterized in that, Includes the defrosting control device as described in any one of claims 9 to 15.

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