Electromagnetic coordination litchi freezing and unfreezing device and method based on ultrasonic detection

Abstract

The invention provides an electromagnetic coordination litchi freezing and unfreezing device and method based on ultrasonic detection, the device comprises a cabinet body, a rotating shaft is arranged in the cabinet body, and the rotating shaft is connected with an ultrasonic detection device for detecting the structural change of the surface layer and the interior of a litchi. The side, away from the rotating shaft, of the ultrasonic detection device is connected with a tray used for placing litchis. An electromagnetic field generator is arranged in the cabinet body close to the tray and is used for forming an electromagnetic field in the cabinet body and adjusting parameters of the electromagnetic field according to a detection result of the ultrasonic detection device. The change of the internal structure of the litchi is monitored in real time by utilizing an ultrasonic detection technology, and accurate feedback is provided for the freezing process and the unfreezing process of the litchi. According to the change of the internal structure of the litchis, the electromagnetic field generator is adopted to adjust electromagnetic parameters, the uniformity and consistency of the freezing process and the thawing process of the litchis can be ensured, and the controllability of the quality of the litchis can be improved by adopting the freezing and thawing device for the litchis.

Description

Technical Field

[0001] The present invention relates to the technical field of litchi storage, and particularly to an electromagnetic coordinated litchi freezing and thawing device and method based on ultrasonic detection. Background Art

[0002] In the field of litchi processing and storage, freezing and thawing technologies have a decisive impact on the quality, safety and shelf life of litchi. However, the existing technologies have the following limitations: (1) The traditional freezing methods such as air freezing and mechanical refrigeration are slow in speed, easy to form large ice crystals, and damage the cell structure, resulting in juice loss, poor texture and bad taste after thawing. (2) It is difficult for the existing technologies to ensure the temperature uniformity of litchi during the freezing process and the thawing process, making the litchi overheat locally, resulting in affecting the stability of litchi quality. (3) The traditional thawing methods such as natural thawing, water thawing and air thawing have long thawing time, low efficiency, and are easy to breed microorganisms, increasing the risk of litchi spoilage. (4) The existing method of solely using electromagnetic freezing for litchi has low efficiency and cannot achieve rapid freezing of litchi.

[0003] In terms of litchi quality detection, although the traditional physical and chemical detection methods are accurate, they require destructive sampling, have problems of cumbersome detection processes and long time consumption, and cannot monitor the production process in real time. The emerging non-destructive detection technologies such as hyperspectral, Raman spectroscopy, electronic nose, near-infrared spectroscopy and ultrasonic technology each have their own advantages, but there are still deficiencies in terms of detection accuracy, real-time performance, cost and operation complexity. The hyperspectral technology equipment is expensive and the data processing is complex. The signal of Raman spectroscopy is weak and the cost is high. The electronic nose can only detect volatile components, and the accuracy of near-infrared spectroscopy is greatly affected by the environment. Although ultrasonic detection technology has been widely used in other fields, it has not been fully developed and applied in litchi freezing, litchi thawing and litchi quality detection. The special structure and components of litchi make it difficult for traditional detection technologies to comprehensively and real-time monitor its internal changes, especially during the freezing process and the thawing process.

[0004] Therefore, a device is needed that can quickly and uniformly freeze and thaw litchi, and can perform real-time regulation of freezing and thawing according to the results of non-destructive detection, so as to improve the quality and safety of litchi. Summary of the Invention

[0005] To overcome the problems existing in the related technologies, the purpose of the present invention is to provide an electromagnetic coordinated litchi freezing and thawing device and method based on ultrasonic detection, wherein the device can quickly and uniformly freeze and thaw litchi, and can perform real-time regulation of freezing and thawing according to the results of non-destructive detection, so as to improve the quality and safety of litchi.

[0006] An electromagnetic coordination litchi freezing and thawing device based on ultrasonic detection, comprising a cabinet body, wherein a rotating shaft is arranged inside the cabinet body, and the rotating shaft is connected with an ultrasonic detection device for detecting the structural changes on the surface and inside of the litchi; one side of the ultrasonic detection device away from the rotating shaft is connected with a tray for placing the litchi; an electromagnetic field generator is arranged in the cabinet body near the tray, and the electromagnetic field generator is used for forming an electromagnetic field inside the cabinet body and adjusting the parameters of the electromagnetic field according to the detection results of the ultrasonic detection device.

[0007] In a preferred technical solution of the present invention, the ultrasonic detection device comprises a plurality of high-frequency detection units and a plurality of low-frequency detection units. The high-frequency detection units are used for detecting the shallow structural changes on the surface of the litchi, and the low-frequency detection units are used for detecting the deep structural changes inside the litchi.

[0008] In a preferred technical solution of the present invention, the electromagnetic field generator is arranged around the inside of the cabinet body, and the electromagnetic field generator is of a multi-layer spiral coil structure.

[0009] In a preferred technical solution of the present invention, an atomizing spray head is arranged near the tray, the atomizing spray head faces the tray, and the atomizing spray head is used for spraying a freezing medium onto the litchi in the tray.

[0010] In a preferred technical solution of the present invention, the electromagnetic coordination litchi freezing and thawing device based on ultrasonic detection further comprises a hose. A freezing medium tank is arranged outside the cabinet body, the freezing medium tank is connected with the first end of the hose, and the second end of the hose is connected with the atomizing spray head.

[0011] In a preferred technical solution of the present invention, the hose comprises a first pipeline and a second pipeline. The first end of the first pipeline is connected with the freezing medium tank; the second end of the first pipeline and the first end of the second pipeline are both connected with a pipeline adapter, and the second end of the second pipeline is connected with the atomizing spray head.

[0012] In a preferred technical solution of the present invention, a variable-frequency magnetic flow pump is arranged near the pipeline adapter on the first pipeline, and the variable-frequency magnetic flow pump is used for adjusting the pressure of the freezing medium.

[0013] The present invention also provides an electromagnetic coordination litchi freezing and thawing method based on ultrasonic detection, comprising:

[0014] Placing the litchi on the tray;

[0015] Selecting a working mode, where the working mode includes an electromagnetic freezing mode, an electromagnetic thawing mode, an electromagnetic-assisted rapid freezing mode with a freezing medium, and an intelligent mode;

[0016] If the working mode is the electromagnetic freezing mode, start the electromagnetic field generator and adjust the electric field strength and magnetic field strength;

[0017] Use the ultrasonic detection device to detect the internal structural changes of the litchi, and use a temperature sensor to detect the temperature of the litchi;

[0018] According to the internal structural changes of the litchi and the temperature of the litchi, adjust the electric field strength and magnetic field strength in real time;

[0019] Turn on the variable-frequency magnetic flow pump, and control the atomizing spray head to spray the freezing medium on the litchi.

[0020] In a preferred technical solution of the present invention, the adjusting the electric field strength and magnetic field strength in real time according to the internal structural changes of the litchi and the temperature of the litchi includes:

[0021] If the freezing time is less than or equal to the freezing time threshold, set the magnetic field strength to the first magnetic field strength and set the electric field strength to the first electric field strength;

[0022] If the freezing time is greater than the freezing time threshold, set the magnetic field strength to the second magnetic field strength and set the electric field strength to the second electric field strength; wherein, the second magnetic field strength is less than the first magnetic field strength, and the second electric field strength is less than the first electric field strength.

[0023] In a preferred technical solution of the present invention, after selecting the working mode, it further includes:

[0024] If the working mode is the electromagnetic thawing mode, start the electromagnetic field generator, set the magnetic field strength to the third magnetic field strength, and set the electric field strength to the third electric field strength;

[0025] If the working mode is the electromagnetic-assisted rapid freezing mode of the freezing medium, under the action of the variable-frequency magnetic flow pump, the freezing medium flows from the freezing medium tank into the atomizing spray head, and control the atomizing spray head to evenly spray the freezing medium on the litchi; start the magnetic field generator to cooperate with the freezing medium to accelerate the freezing process of the litchi;

[0026] If the working mode is the intelligent mode, use the high-frequency detection unit to detect the shallow structure of the litchi, and use the low-frequency detection unit to detect the deep structure of the litchi; judge the quality of the litchi according to the shallow structure, the deep structure and the temperature of the litchi; if the quality of the litchi does not meet the standard, remind the user not to freeze or recommend a freezing plan.

[0027] The beneficial effects of the present invention are:

[0028] The electromagnetic coordination litchi freezing and thawing device based on ultrasonic detection provided by the present invention includes a cabinet body. A rotating shaft is arranged inside the cabinet body, and the rotating shaft is connected with an ultrasonic detection device for detecting the structural changes on the surface and inside of the litchi. On the side of the ultrasonic detection device far from the rotating shaft, there is a tray connected, and the tray is used for placing litchis. An electromagnetic field generator is arranged near the tray inside the cabinet body. The electromagnetic field generator is used to form an electromagnetic field inside the cabinet body and adjust the parameters of the electromagnetic field according to the detection results of the ultrasonic detection device. When litchis are placed on the tray of the present invention, when ultrasonic waves propagate inside the litchis, when encountering tissues with different densities and elasticities, the propagation speed, attenuation degree, and reflection situation will change. When the structure of normal litchi cells is intact, the propagation of ultrasonic waves is relatively stable; if the litchi cells are damaged due to freezing and the internal structure changes, the propagation characteristics will produce corresponding changes. For example, the ice crystals formed by freezing will cause the propagation speed of ultrasonic waves to decrease and the attenuation to increase. By analyzing these characteristic changes of the echo signals received by the ultrasonic detection device, the structural changes inside the litchi can be inferred. The present invention uses ultrasonic detection technology to monitor the structural changes inside the litchi in real time and provide accurate feedback for the freezing process and thawing process of the litchi. According to the structural changes inside the litchi, the electromagnetic parameters are adjusted by using the electromagnetic field generator, which can ensure the uniformity and consistency of the litchi freezing process and thawing process. Using the litchi freezing and thawing device of the present invention can improve the controllability of litchi quality and reduce the quality fluctuations of litchis caused by improper operation. Description of the Drawings

[0029] Figure 1 is the first structural schematic diagram of the electromagnetic coordination litchi freezing and thawing device based on ultrasonic detection of the present invention;

[0030] Figure 2 is the second structural schematic diagram of the electromagnetic coordination litchi freezing and thawing device based on ultrasonic detection of the present invention;

[0031] Figure 3 is the schematic diagram of the ultrasonic detection device of the present invention;

[0032] Figure 4 is the flow chart of the electromagnetic coordination litchi freezing and thawing method based on ultrasonic detection of the present invention.

[0033] Reference Numerals: 1, cabinet body; 2, rotating shaft; 3, ultrasonic detection device; 4, tray; 5, electromagnetic field generator; 6, high-frequency detection unit; 7, low-frequency detection unit; 8, atomizing spray head; 9, hose; 10, freezing medium tank; 11, first pipeline; 12, second pipeline; 13, pipeline adapter; 14, variable-frequency magnetic flow pump; 15, cabinet door; 16, control panel; 17, handle; 18, observation window; 19, temperature sensor. Detailed Embodiments

[0034] The preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0035] Example 1

[0036] As Figures 1 - 3 shown, this embodiment provides an electromagnetic coordination litchi freezing and thawing device based on ultrasonic detection, including a cabinet 1. Inside the cabinet 1, a rotating shaft 2 is provided, and the rotating shaft 2 is connected to an ultrasonic detection device 3 for detecting the structural changes on the surface and inside of the litchi. On the side of the ultrasonic detection device 3 away from the rotating shaft 2, a tray 4 is connected, and the tray 4 is used to place the litchi. An electromagnetic field generator 5 is provided near the tray 4 inside the cabinet 1. The electromagnetic field generator 5 is used to form an electromagnetic field inside the cabinet 1 and adjust the parameters of the electromagnetic field according to the detection results of the ultrasonic detection device 3.

[0037] The ultrasonic detection device 3 includes a plurality of high-frequency detection units 6 and a plurality of low-frequency detection units 7. The high-frequency detection units 6 are used to detect the shallow structural changes on the surface of the litchi, and the low-frequency detection units 7 are used to detect the deep structural changes inside the litchi.

[0038] The working frequency of the high-frequency detection unit 6 is 500 kHz and is used to detect whether there are fine cracks on the litchi epidermis. The working frequency of the low-frequency detection unit 7 is 50 kHz and is used to detect whether there are damages caused by slight extrusion inside the litchi. The electromagnetic coordination litchi freezing and thawing device based on ultrasonic detection further includes a controller. The input end of the controller is electrically connected to the ultrasonic detection device 3, and the output end of the controller is electrically connected to the electromagnetic field generator 5. The controller judges whether the quality of the litchi meets the standard according to the ultrasonic data. If the quality of the litchi does not meet the standard, the user is prompted not to freeze the litchi or a freezing scheme is recommended. The controller is electrically connected to a display screen and a speaker. The way the controller prompts the user can be to display the quality of the litchi on the display screen or to send a prompt voice to the user using the speaker. In addition, the electromagnetic coordination litchi freezing and thawing device of the present invention can also monitor the freezing and thawing conditions of the litchi, and adjust the electric field strength and magnetic field strength according to the freezing and thawing conditions to realize intelligent real-time control of the litchi freezing process and thawing process.

[0039] On one side of the cabinet body 1, a cabinet door 15 is installed. A handle 17 and an observation window 18 are provided on the cabinet door 15. A control panel 16 is provided on the cabinet body 1. The control panel 16 is electrically connected to the controller. The control panel 16 is used to operate and display the status of the litchi freezing and thawing device. The rotating shaft 2 is located on the bottom surface inside the cabinet body 1. The rotating shaft 2 can be driven by a motor or by a gear, and no limitation is made here. Above the rotating shaft 2, an ultrasonic detection device 3 is connected. On the side of the ultrasonic detection device 3 away from the rotating shaft 2, a tray 4 is connected. Litchis are placed on the tray 4. The rotating shaft 2 drives the ultrasonic detection device 3 to rotate, thereby driving the tray 4 to rotate. At the top of the cabinet body 1, an atomizing spray head 8 is provided. There are 6 atomizing spray nozzles in total for the atomizing spray head 8. Each atomizing spray nozzle faces the tray 4, so that the atomizing spray nozzles evenly spray the freezing medium onto the litchis in the tray 4.

[0040] The ultrasonic detection device 3 monitors the internal structure changes of litchis during the freezing process and the thawing process in real time, and transmits the detection signals to the controller. When ultrasonic waves propagate inside litchis, when encountering tissues with different densities and elasticities, the propagation speed, attenuation degree, and reflection situation will change. When the cell structure of normal litchis is intact, the propagation of ultrasonic waves is relatively stable; if the litchi cells are damaged due to freezing and the internal structure changes, the propagation characteristics will change. For example, the ice crystals formed by freezing will cause the propagation speed of ultrasonic waves to decrease and the attenuation to increase. By analyzing these characteristic changes of the echo signals received by the ultrasonic transducer, the internal structure changes of litchis are inferred.

[0041] The electromagnetic field generator 5 is arranged around the inside of the cabinet body 1. The electromagnetic field generator 5 is a multi-layer spiral coil structure. According to the Biot-Savart law, for a straight current-carrying wire, the magnitude of the magnetic induction intensity B generated at a distance r from the wire is as follows:

[0042]

[0043] where μ 0 is the magnetic permeability of vacuum, I is the current intensity, is the current element vector, is the vector from the current element to the field point, and r is the distance from the current element to the field point.

[0044] For the electrostatic field, Coulomb's law is expressed as

[0045] where F is the force between two point charges, k is the electrostatic force constant, q 1 is the electric charge of the first point charge, q 2 is the electric charge of the second point charge, r' is the distance between the two point charges. The above formula can be used to indirectly correlate the calculations related to the electric field. The following formula is used to calculate the electric field strength E:

[0046]

[0047] Among them, E is the electric field strength and q is the electric charge of the test charge. The electric field distribution inside the cabinet is analyzed based on the electric field strength E.

[0048] The electromagnetic coordinated litchi freezing and thawing device based on ultrasonic detection provided in this embodiment includes a cabinet. A rotating shaft is arranged inside the cabinet, and the rotating shaft is connected with an ultrasonic detection device for detecting the structural changes on the surface and inside of the litchi. One side of the ultrasonic detection device away from the rotating shaft is connected with a tray for placing the litchi. An electromagnetic field generator is arranged near the tray inside the cabinet, and the electromagnetic field generator is used to form an electromagnetic field inside the cabinet and adjust the parameters of the electromagnetic field according to the detection results of the ultrasonic detection device. Litchis are placed on the tray of the present invention. When ultrasonic waves propagate inside the litchi, when encountering tissues with different densities and elasticities, the propagation speed, attenuation degree, and reflection situation will change. When the structure of normal litchi cells is intact, the propagation of ultrasonic waves is relatively stable; if the litchi cells are damaged by freezing and the internal structure changes, the propagation characteristics will change correspondingly. For example, the ice crystals formed by freezing will reduce the propagation speed of ultrasonic waves and increase the attenuation. By analyzing these characteristic changes of the echo signals received by the ultrasonic detection device, the internal structural changes of the litchi can be inferred. The present invention uses ultrasonic detection technology to monitor the internal structural changes of litchis in real time, providing precise feedback for the freezing process and thawing process of litchis. According to the internal structural changes of the litchi, the electromagnetic parameters are adjusted by using the electromagnetic field generator, which can ensure the uniformity and consistency of the litchi freezing process and thawing process. Using the litchi freezing and thawing device of the present invention can improve the controllability of litchi quality and reduce the quality fluctuations of litchis caused by improper operation.

[0049] Embodiment 2

[0050] As Figures 1 - 3 shown, the electromagnetic coordinated litchi freezing and thawing device based on ultrasonic detection provided in this embodiment includes a cabinet 1. A rotating shaft 2 is arranged inside the cabinet 1, and the rotating shaft 2 is connected with an ultrasonic detection device 3 for detecting the structural changes on the surface and inside of the litchi. One side of the ultrasonic detection device 3 away from the rotating shaft 2 is connected with a tray 4 for placing the litchi. An electromagnetic field generator 5 is arranged near the tray 4 inside the cabinet 1, and the electromagnetic field generator 5 is used to form an electromagnetic field inside the cabinet 1 and adjust the parameters of the electromagnetic field according to the detection results of the ultrasonic detection device 3.

[0051] An atomizing spray head 8 is arranged near the tray 4. The atomizing spray head 8 faces the tray 4, and the atomizing spray head 8 is used to spray the freezing medium onto the litchi in the tray 4.

[0052] The electromagnetic coordination litchi freezing and thawing device further includes a hose 9. A freezing medium tank 10 is arranged outside the cabinet body 1. The freezing medium tank 10 is connected to the first end of the hose 9, and the second end of the hose 9 is connected to the atomizing spray head 8.

[0053] The hose 9 includes a first pipeline 11 and a second pipeline 12. The first end of the first pipeline 11 is connected to the freezing medium tank 10; the second end of the first pipeline 11 and the first end of the second pipeline 12 are both connected to a pipeline adapter 13, and the second end of the second pipeline 12 is connected to the atomizing spray head 8.

[0054] The atomizing spray head 8 has a total of 6 atomizing spray ports, and each atomizing spray port faces the tray 4, so that the atomizing spray head 8 evenly sprays the freezing medium onto the litchis in the tray 4. The hose 9 is used to connect the atomizing spray head 8 and the freezing medium tank 10. The freezing medium flows out of the freezing medium tank 10, flows through the hose 9 to the atomizing spray head 8, and then sprays from the atomizing spray head 8 onto the surface of the litchis.

[0055] The first pipeline 11 extends in the horizontal direction, and the second pipeline 12 extends in the height direction. The pipeline adapter 13 is used to connect the first pipeline 11 and the second pipeline 12, changing the extension direction of the hose 9 from horizontal extension to vertical extension. The overall shape of the hose 9 is L-shaped. The first pipeline 11 is located outside the cabinet body 1, and a part of the second pipeline 12 is located outside the cabinet body 1 and another part is located inside the cabinet body 1.

[0056] A variable-frequency magnetic flow pump 14 is arranged near the pipeline adapter 13 of the first pipeline 11. The variable-frequency magnetic flow pump 14 is used to adjust the pressure of the freezing medium. In this embodiment, the freezing medium is a mixture of propylene glycol and water.

[0057] According to Bernoulli's equation where a is a constant, p is the pressure, ρ is the fluid density, v is the flow velocity, and h is the height. In the freezing medium circulation system, by adjusting the power of the variable-frequency magnetic flow pump 14, the pressure of the freezing medium can be changed, thereby affecting the spraying uniformity and coverage. Appropriate pressure can ensure that the freezing medium is evenly sprayed on the surface of the litchis, improving the freezing uniformity.

[0058] The variable-frequency magnetic flow pump 14 has the functions of transporting the freezing medium and adjusting the spraying rate of the atomizing spray head 8 in the food freezing system. By changing the working frequency, the variable-frequency magnetic flow pump 14 can adjust the flow rate, thereby controlling the spraying rate of the atomizing spray head 8. For example, increasing the frequency at the initial stage of freezing to increase the spraying rate, so that the litchis can be quickly cooled. Reducing the frequency in the later stage to avoid over-freezing, thereby achieving uniform freezing.

[0059] Temperature sensors 19 are provided at various locations inside the cabinet body 1, and several of them are distributed near the tray 4. The temperature sensors 19 are used to monitor the internal temperature of the lychees in real time and feed the temperature data back to the controller.

[0060] In this embodiment, an atomizing spray head 8 is provided near the tray 4. The atomizing spray head 8 faces the tray 4, and the atomizing spray head 8 is used to spray the freezing medium onto the lychees in the tray 4. The electromagnetic coordinated lychee freezing and thawing device based on ultrasonic detection further includes a hose 9. A freezing medium tank 10 is provided outside the cabinet body 1. The freezing medium tank 10 is connected to the first end of the hose 9, and the second end of the hose 9 is connected to the atomizing spray head 8. Through the synergistic effect of electromagnetic technology and the freezing medium, the present invention realizes a fast and uniform freezing process, effectively reduces the formation of ice crystals, thereby reducing the damage to the cell structure of the lychees. This improvement significantly reduces the problems of juice loss, texture deterioration, and taste decline after the lychees are thawed, and improves the stability of the lychee quality.

[0061] Embodiment 3

[0062] As Figure 4 shown, this embodiment provides an electromagnetic coordinated lychee freezing and thawing method based on ultrasonic detection, including:

[0063] S1: Place the lychees on the tray.

[0064] S2: Select a working mode, and the working mode includes an electromagnetic freezing mode, an electromagnetic thawing mode, an electromagnetic assisted freezing medium rapid freezing mode, and an intelligent mode.

[0065] S3: If the working mode is the electromagnetic freezing mode, start the electromagnetic field generator and adjust the electric field strength and magnetic field strength.

[0066] S4: Use the ultrasonic detection device to detect the internal structural changes of the lychees, and use the temperature sensor to detect the temperature of the lychees.

[0067] S5: According to the internal structural changes of the lychees and the temperature of the lychees, adjust the electric field strength and magnetic field strength in real time.

[0068] S6: Turn on the variable frequency magnetic flow pump and control the atomizing spray head to spray the freezing medium onto the lychees.

[0069] The electromagnetic coordination litchi freezing and thawing device based on ultrasonic detection of the present invention has a total of 4 working modes, namely electromagnetic freezing mode, electromagnetic thawing mode, electromagnetic-assisted rapid freezing mode with freezing medium, and intelligent mode. If the working mode is the electromagnetic freezing mode, start the electromagnetic field generator 5, adjust the electric field strength and magnetic field strength to generate a specific electromagnetic field. The controller adjusts the electric field strength and magnetic field strength of the electromagnetic field inside the cabinet 1 in real time according to the changes in the internal structure of the litchi monitored by the ultrasonic detection device 3 and the temperature data of the inside of the litchi monitored by the temperature sensor 19.

[0070] The real-time adjustment of the electric field strength and magnetic field strength according to the changes in the internal structure of the litchi and the temperature of the litchi includes:

[0071] S51: If the freezing time is less than or equal to the freezing time threshold, set the magnetic field strength to the first magnetic field strength and the electric field strength to the first electric field strength.

[0072] S52: If the freezing time is greater than the freezing time threshold, set the magnetic field strength to the second magnetic field strength and the electric field strength to the second electric field strength; wherein, the second magnetic field strength is less than the first magnetic field strength, and the second electric field strength is less than the first electric field strength.

[0073] In the initial stage of freezing, appropriately increase the magnetic field strength and electric field strength. The range of the first magnetic field strength is 10 - 20 mT, and the range of the first electric field strength is 4 - 6 kV / cm. Using the first magnetic field strength and the first electric field strength in the initial stage of freezing can increase the orderly arrangement speed of water molecules. As the freezing process progresses, gradually reduce the magnetic field strength and electric field strength according to the formation of ice crystals inside the litchi, that is, use the second magnetic field strength and the second electric field strength to ensure the uniform growth of ice crystals. The range of the second magnetic field strength is 5 - 10 mT, and the range of the second electric field strength is 3 - 4 kV / cm. At the same time, the temperature sensor 19 monitors the internal temperature of the litchi in real time and feeds it back to the controller, so as to ensure that the freezing process of the litchi is carried out within the set temperature range.

[0074] After selecting the working mode, it also includes:

[0075] S3’: If the working mode is the electromagnetic thawing mode, start the electromagnetic field generator, set the magnetic field strength to the third magnetic field strength, and set the electric field strength to the third electric field strength.

[0076] S4’: If the working mode is the electromagnetic-assisted rapid freezing mode with freezing medium, under the action of the variable-frequency magnetic flow pump, the freezing medium flows from the freezing medium tank into the atomizing spray head, and control the atomizing spray head to evenly spray the freezing medium on the litchi; start the magnetic field generator to cooperate with the freezing medium to accelerate the freezing process of the litchi.

[0077] S5’: If the working mode is the intelligent mode, a high-frequency detection unit is adopted to detect the shallow structure of the litchi, and a low-frequency detection unit is adopted to detect the deep structure of the litchi; the litchi quality is judged according to the shallow structure, the deep structure and the temperature of the litchi; if the litchi quality does not meet the standard, the user is reminded not to freeze, or a freezing scheme is recommended.

[0078] In the electromagnetic thawing mode, the magnetic field generator adjusts the electromagnetic field parameters, sets the magnetic field intensity to the third magnetic field intensity, and sets the electric field intensity to the third electric field intensity. The range of the third magnetic field intensity is 5 - 20 mT, and the range of the third electric field intensity is 3 - 6 kV / cm, so that the water molecules inside the litchi generate resonance, and uniform heating and thawing of the inside of the litchi are realized under the action of heat generated by friction.

[0079] In the electromagnetic-assisted rapid freezing mode of the freezing medium, the freezing medium in the freezing medium tank 10 is evenly sprayed on the litchi through the atomizing spray head 8 under the action of the variable-frequency magnetic flow pump 14. At the same time, the magnetic field generator generates an electromagnetic field to cooperate with the freezing medium to accelerate the freezing process and improve the freezing efficiency and uniformity.

[0080] In the intelligent mode, the high-frequency detection unit 6 of the ultrasonic detection device 3 uses electromagnetic waves with a frequency higher than 100 kHz to detect the shallow structure on the surface of the litchi. The low-frequency detection unit 7 of the ultrasonic detection device 3 uses electromagnetic waves with a frequency of 20 - 100 kHz to detect the deep structure inside the litchi, and real-time monitors the change of the internal structure of the litchi during the processing. According to the ultrasonic detection data, the quality of the litchi is immediately analyzed. If it is detected that the quality parameters of the litchi deviate from the preset standard, the controller automatically adjusts the electromagnetic field parameters of the magnetic field generator and the working state of the variable-frequency magnetic flow pump 14 to ensure the litchi quality. For example, when the ultrasonic detection device 3 starts to work, the high-frequency detection unit 6 with a working frequency of 500 kHz finds that there are fine cracks on the epidermis of some litchis, and the low-frequency detection unit 7 with a working frequency of 50 kHz detects damage caused by slight extrusion inside the litchi, then the controller judges that the litchi quality does not meet the standard according to the ultrasonic data. At this time, the controller reminds the user not to freeze, or recommends a freezing scheme. The controller automatically increases the magnetic field intensity of the magnetic field generator from 8 mT to 10 mT, increases the electric field intensity from 3.5 kV / cm to 4 kV / cm, and increases the flow rate of the variable-frequency magnetic flow pump 14 by 20%, which can make the freezing more uniform, improve the freezing speed, and reduce the damage to the damaged litchi cells. After freezing, it enters the thawing link. It is detected by ultrasonic that the ice crystals inside the litchi melt unevenly, and the melting rate in some areas is slower. The controller reduces the magnetic field intensity to 6 mT and the electric field intensity to 3 kV / cm.

[0081] End process: When the set freezing or thawing time and temperature are reached, the device automatically stops running and emits a prompt sound. The control panel 16 displays the working conditions of this operation, including the processing time, the actually reached temperature, and the quality data of the lychees analyzed by ultrasonic detection. If the system analyzes improvement measures based on the working data of this operation and the built-in algorithm, it will promptly give improvement strategies on the control panel 16, such as adjusting the electromagnetic field parameter range and the flow rate of the freezing medium for the next processing. The operator opens the cabinet door 15, takes out the lychees, and can also click on the options in the control panel 16 to upload their opinions on this processing process, such as the actual taste and appearance changes of the lychees, etc., for subsequent optimization of the device operation parameters and algorithms.

[0082] The control method includes: (1) Setting parameters. Input parameters such as the food type, initial temperature, target freezing temperature or target thawing temperature, freezing time or thawing time, etc. on the control panel 16, and then select to run directly or enter the intelligent mode. (2) Starting the device. Press the start button to start the corresponding components according to the selected mode. In the electromagnetic freezing mode, start the magnetic field generator to adjust the current magnitude and frequency to generate a specific electromagnetic field. At the same time, decide whether to start the freezing medium circulation system according to whether electromagnetic-assisted freezing medium is used for freezing. The freezing medium circulation system includes a freezing medium tank 10, a variable-frequency magnetic flow pump 14, and an atomizing spray head 8.

[0083] In the electromagnetic thawing mode, start the magnetic field generator to adjust the electromagnetic field parameters; in the electromagnetic-assisted freezing medium freezing mode, it is necessary to start the magnetic field generator and the freezing medium circulation system. In addition, regardless of which mode, the ultrasonic detection device 3 can be started synchronously for real-time monitoring. Before the device starts, an automatic safety self-check program is triggered to check whether the connections of all components are stable, whether the circuit is normal, whether the freezing medium leaks, etc. Only when all safety indicators meet the standards will the device run officially.

[0084] In the intelligent mode, the ultrasonic detection device 3 monitors the internal structure changes of the litchi in real time, and the temperature sensor 19 monitors the internal temperature of the litchi in real time. The control system analyzes the quality of the litchi immediately according to the monitored data. If the quality is abnormal or does not meet the standard, it will remind the user not to freeze, or recommend a freezing solution; or adjust the electromagnetic field parameters of the magnetic field generator and the working state of the variable-frequency magnetic flow pump 14 in real time, so as to improve the speed and uniformity of the freezing process and thawing process on the premise of ensuring the quality of the litchi. At the same time, the system continuously monitors the operating state of the equipment. Once safety hazards such as current overload and abnormal temperature rise are detected, the safety protection mechanism is immediately triggered. At the hardware level, the relevant circuit is automatically cut off. For example, the power supply of the magnetic field generator and the variable-frequency magnetic flow pump 14 is cut off by the overcurrent protection switch set in the circuit; at the software level, the equipment operation instruction is stopped from being executed, and detailed fault information and safety prompts are displayed on the control panel 16 to guide the operator to troubleshoot problems. After the equipment stops running, a prompt sound is emitted, the control panel 16 shows the working conditions and improvement strategies of this time, and receives the opinions uploaded by the operator.

[0085] The electromagnetic coordination litchi freezing and thawing method based on ultrasonic detection in this embodiment includes placing the litchi on the tray 4 and selecting the working mode. The working modes include electromagnetic freezing mode, electromagnetic thawing mode, electromagnetic-assisted rapid freezing mode with freezing medium, and intelligent mode. If the working mode is the electromagnetic freezing mode, the electromagnetic field generator 5 is started, and the electric field intensity and magnetic field intensity are adjusted. The ultrasonic detection device 3 is used to detect the internal structure changes of the litchi, and the temperature sensor 19 is used to detect the temperature of the litchi. According to the internal structure changes of the litchi and the temperature of the litchi, the electric field intensity and magnetic field intensity are adjusted in real time. The variable-frequency magnetic flow pump 14 is turned on, and the atomizing spray head 8 is controlled to spray the freezing medium on the litchi. Since water molecules are polar molecules, in an electrostatic field, water molecules will undergo orientation and further induction to form a more ordered cluster structure, resulting in a decrease in free energy. In a magnetic field, the electron spin and nuclear spin of water molecules will be consistent with the magnetic field direction, causing the spin nuclei to precess along the direction of the external magnetic field, enhancing the thermal vibration of the molecules. This effect on water molecules makes the heat exchange between the freezing medium and the litchi more efficient. When freezing the litchi, the action of the electromagnetic field makes it easier for water molecules to interact with the freezing medium, accelerating heat transfer, thereby achieving rapid freezing of the litchi.

[0086] Embodiment 4

[0087] An embodiment of the present application further provides a computer device, which may be a server. Among them, the computer device includes a processor, a memory, a network interface, and a database connected through a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface of the computer device is used to communicate with an external terminal through a network connection.

[0088] This embodiment further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the electromagnetic coordination litchi freezing and thawing method based on ultrasonic detection in Embodiment 3. It can be understood that the computer-readable storage medium in this embodiment can be a volatile readable storage medium or a non-volatile readable storage medium.

[0089] It should be noted that in this article, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, device, article or method including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, device, article or method. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, device, article or method including the element.

[0090] The above are only the preferred embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, are equally included in the patent protection scope of the present application.

Claims

1. An electromagnetic coordinated litchi freezing and thawing device based on ultrasonic detection, characterized in that: It comprises a cabinet body, wherein a rotating shaft is arranged inside the cabinet body, and the rotating shaft is connected to an ultrasonic detection device for detecting changes in the surface and internal structure of litchi; a tray is connected to the side of the ultrasonic detection device away from the rotating shaft, and the tray is used to place the litchi; an electromagnetic field generator is arranged in the cabinet body near the tray, and the electromagnetic field generator is used to form an electromagnetic field inside the cabinet body, and adjust the parameters of the electromagnetic field according to the detection results of the ultrasonic detection device.

2. The electromagnetic coordinated litchi freezing and thawing device based on ultrasonic detection according to claim 1 is characterized in that: The ultrasonic detection device includes a plurality of high-frequency detection units and a plurality of low-frequency detection units. The high-frequency detection units are used to detect the shallow structural changes on the surface of litchi, and the low-frequency detection units are used to detect the deep structural changes inside the litchi.

3. The electromagnetic coordinated litchi freezing and thawing device based on ultrasonic detection according to claim 1 is characterized in that: The electromagnetic field generator is arranged around the interior of the cabinet, and the electromagnetic field generator is a multi-layer spiral coil structure.

4. The electromagnetic coordinated litchi freezing and thawing device based on ultrasonic detection according to claim 1 is characterized in that: An atomizing spray head is arranged near the tray and faces the tray. The atomizing spray head is used to spray a freezing medium onto the lychees in the tray.

5. The electromagnetic coordinated litchi freezing and thawing device based on ultrasonic detection according to claim 4 is characterized in that: It also includes a hose. A refrigerating medium tank is arranged outside the cabinet. The refrigerating medium tank is connected to a first end of the hose, and a second end of the hose is connected to the atomizing spray head.

6. The electromagnetic coordinated litchi freezing and thawing device based on ultrasonic detection according to claim 5 is characterized in that: The hose includes a first pipe and a second pipe, the first end of the first pipe is connected to the freezing medium tank; the second end of the first pipe and the first end of the second pipe are both connected to the pipe adapter, and the second end of the second pipe is connected to the atomizing spray head.

7. The electromagnetic coordinated litchi freezing and thawing device based on ultrasonic detection according to claim 6 is characterized in that: A variable frequency magnetic flow pump is arranged near the pipeline adapter of the first pipeline, and the variable frequency magnetic flow pump is used to adjust the pressure of the refrigerant medium.

8. An electromagnetic coordinated lychee freezing and thawing method based on ultrasonic detection, characterized in that: The electromagnetic coordinated lychee freezing and thawing device based on ultrasonic detection applied to any one of claims 1 to 7, the method comprising: placing the lychees on a tray; Selecting a working mode, wherein the working modes include electromagnetic freezing mode, electromagnetic thawing mode, electromagnetic assisted freezing medium rapid freezing mode and intelligent mode; If the working mode is the electromagnetic freezing mode, the electromagnetic field generator is started to adjust the electric field strength and the magnetic field strength; The ultrasonic detection device is used to detect the structural changes inside the litchi, and the temperature sensor is used to detect the temperature of the litchi; According to the changes in the internal structure of the litchi and the temperature of the litchi, the electric field strength and the magnetic field strength are adjusted in real time; The variable frequency magnetic flow pump is turned on, and the atomizing spray head is controlled to spray the freezing medium on the litchi.

9. The electromagnetic coordinated lychee freezing and thawing method based on ultrasonic detection according to claim 8, characterized in that: The method of adjusting the electric field strength and the magnetic field strength in real time according to the internal structure changes of the litchi and the temperature of the litchi comprises: If the freezing time is less than or equal to the freezing time threshold, the magnetic field strength is set to the first magnetic field strength, and the electric field strength is set to the first electric field strength; If the freezing time is greater than the freezing time threshold, the magnetic field strength is set to the second magnetic field strength, and the electric field strength is set to the second electric field strength; wherein the second magnetic field strength is smaller than the first magnetic field strength, and the second electric field strength is smaller than the first electric field strength.

10. The electromagnetic coordinated lychee freezing and thawing method based on ultrasonic detection according to claim 8, characterized in that: After selecting the working mode, the method further includes: If the working mode is the electromagnetic thawing mode, the electromagnetic field generator is started, the magnetic field strength is set to the third magnetic field strength, and the electric field strength is set to the third electric field strength; If the working mode is the electromagnetic-assisted freezing medium rapid freezing mode, the freezing medium flows from the freezing medium tank into the atomizing spray head under the action of the variable frequency magnetic flow pump, and the atomizing spray head is controlled to spray the freezing medium evenly on the litchi; the magnetic field generator is started to cooperate with the freezing medium to accelerate the freezing process of the litchi; If the working mode is the intelligent mode, a high-frequency detection unit is used to detect the shallow structure of the litchi, and a low-frequency detection unit is used to detect the deep structure of the litchi; the quality of the litchi is judged according to the shallow structure, the deep structure and the temperature of the litchi; if the quality of the litchi does not meet the standard, the user is reminded not to freeze it, or a freezing plan is recommended.

Images