A quick freezing system and a quick freezing method

Abstract

The application provides a quick freezing system and a quick freezing method, which comprise: a refrigeration cavity, which contains products to be quickly frozen; a first refrigeration module, which is used for providing air cooling to the products in the refrigeration cavity; a second refrigeration module, which comprises a liquid nitrogen nozzle for spraying liquid nitrogen on the products, and the liquid nitrogen nozzle is arranged in the refrigeration cavity; a detection module, which is used for measuring the temperature of the products; and a control module, which is in signal connection with the detection module and the second refrigeration module, and controls the second refrigeration module to be turned on according to the temperature of the products. The quick freezing system and the quick freezing method solve the technical problem of poor quick freezing effect and quality of the food in the quick freezer in the related art.

Description

Technical Field

[0001] This invention relates to the field of quick-freezing equipment technology, and more specifically to a quick-freezing system and quick-freezing method. Background Technology

[0002] With the development of the global economy and the acceleration of the pace of social life, people's demand for fresh food is increasing day by day, and freezing is an effective storage method to maintain food quality and extend its shelf life.

[0003] Currently, food refrigeration and preservation technologies are categorized into slow freezing and rapid freezing based on the freezing rate. Slow freezing involves a long freezing time, a slow passage through the maximum ice crystal formation zone, and the resulting ice crystals are large, few in number, and irregularly distributed. It also causes significant damage to the food's cellular structure, affecting food quality. Rapid freezing, on the other hand, involves a short freezing time, producing numerous needle-like ice crystals that are evenly distributed. It causes minimal damage to the food's cellular structure and has virtually no impact on its flavor and texture.

[0004] Quick-freezing equipment can be categorized into air-circulation, contact, spray, and immersion types based on the heat transfer medium. Each type of refrigeration method has its drawbacks. For example, air-circulation quick-freezing equipment results in greater food dehydration and has a lower heat transfer coefficient. Spray-type quick-freezing equipment requires large amounts of cryogenic fluid for foods that are difficult to freeze completely, increasing costs, and excessively rapid freezing can also cause cryogenic breakage.

[0005] Therefore, existing technologies need further development. Summary of the Invention

[0006] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide a quick-freezing system and quick-freezing method to solve the technical problems of poor quick-freezing effect and quality of food in related technologies.

[0007] To achieve the above technical objectives, the present invention adopts the following technical solution: A quick-freezing system is provided, comprising: a refrigeration chamber containing a product to be quick-frozen; a first refrigeration module providing air cooling to the product within the refrigeration chamber; a second refrigeration module including a liquid nitrogen nozzle for spraying liquid nitrogen onto the product, the liquid nitrogen nozzle being disposed within the refrigeration chamber; a detection module for measuring the temperature of the product; and a control module connected to both the detection module and the second refrigeration module; the control module controls the second refrigeration module to activate based on the product's temperature.

[0008] Furthermore, the quick-freezing system includes: an inlet and an outlet, which are respectively connected to the refrigeration chamber. The product enters the refrigeration chamber through the inlet and leaves the refrigeration chamber through the outlet, which is located at the end of the refrigeration chamber away from the inlet; and a conveyor belt that passes through the refrigeration chamber and carries the product through the inlet and outlet, respectively. The conveyor belt is located below the liquid nitrogen nozzle.

[0009] Furthermore, the quick-freezing system includes a dehumidification system, which includes: a first fan connected to the feed inlet via a first air supply channel perpendicular to the conveyor belt; a second fan connected to the discharge outlet via a second air supply channel perpendicular to the conveyor belt; a dehumidifying evaporator connected to both the first and second fans to provide dry air to both fans; and a return air channel connected to both the feed inlet and the discharge outlet, through which air enters the first and second fans after passing through the dehumidifying evaporator.

[0010] Furthermore, the second refrigeration module includes: a liquid nitrogen storage tank for storing liquid nitrogen; a first pump body, one end of which is connected to the liquid nitrogen storage tank and the other end of which is connected to the liquid nitrogen nozzle; a solenoid valve located between the first pump body and the liquid nitrogen storage tank; and a regulating valve located between the liquid nitrogen nozzle and the first pump body, which controls the flow rate of the liquid nitrogen nozzle by adjusting the opening degree of the regulating valve.

[0011] Furthermore, the quick-freezing system includes a liquid nitrogen nozzle at the discharge port, which is located between the liquid nitrogen nozzle and the discharge port.

[0012] Furthermore, the quick-freezing system includes multiple quick-freezing zones, which are spaced apart within the refrigeration chamber along the extension direction of the conveyor belt; multiple liquid nitrogen nozzles are provided, and each quick-freezing zone is equipped with multiple liquid nitrogen nozzles; detection modules are provided on both sides of the conveyor belt, and each detection module includes multiple sensors, which are set for the multiple quick-freezing zones.

[0013] Furthermore, the multiple quick-freezing zones include a first quick-freezing zone, a second quick-freezing zone, and a third quick-freezing zone arranged at intervals. The first quick-freezing zone is located on the side of the refrigeration chamber closer to the feed inlet, and the third quick-freezing zone is located on the side of the refrigeration chamber farther from the feed inlet.

[0014] Furthermore, the regulating valve includes: a first regulating valve connected to multiple liquid nitrogen nozzles in the first quick-freezing zone; a second regulating valve connected to multiple liquid nitrogen nozzles in the second quick-freezing zone; a third regulating valve connected to multiple liquid nitrogen nozzles in the third quick-freezing zone; and a fourth regulating valve connected to the liquid nitrogen nozzle at the discharge port.

[0015] Furthermore, the first refrigeration module includes: a refrigeration evaporator for supplying cooling to the first refrigeration module; and a condenser assembly connected to the refrigeration evaporator and the dehumidifying evaporator respectively to participate in the refrigeration cycle.

[0016] Furthermore, the quick-freezing system also includes: a collection tray located below the conveyor belt, used to recover liquid nitrogen; a condensing nozzle connected to the collection tray, which sprays the liquid nitrogen from the collection tray onto the surface of the condenser assembly to cool the condenser assembly; and a second pump body located between the collection tray and the condensing nozzle, used to deliver liquid nitrogen into the condensing nozzle.

[0017] Furthermore, the quick-freezing system also includes a filtration device located between the collection tray and the second pump body, used to filter liquid nitrogen.

[0018] A quick-freezing method, applicable to the aforementioned quick-freezing system, includes: measuring a first temperature value A1 of a product entering a refrigeration chamber using a detection module; comparing the value of the first temperature value A1 with an opening threshold B; if A1 > B, keeping the first refrigeration module open; if A1 ≤ B, opening the second refrigeration module; after a period of time, detecting the temperature value A of the product in the refrigeration chamber, comparing the value of A with a proximity threshold C, and controlling the flow rate of liquid nitrogen based on the relationship between A and the proximity threshold C.

[0019] Furthermore, the method for activating the second refrigeration module includes: the second refrigeration module is equipped with a solenoid valve and a first pump body; opening the solenoid valve and the first pump body allows liquid nitrogen to be drawn out from the liquid nitrogen storage tank located within the second refrigeration module.

[0020] Further, the proximity threshold C includes a first proximity threshold C1 and a second proximity threshold C2. A third quick-freezing zone is provided inside the refrigeration chamber, and a liquid nitrogen nozzle is provided in the third quick-freezing zone. The refrigeration chamber includes a liquid nitrogen nozzle at the outlet. The method for controlling the liquid nitrogen flow rate according to the relationship between A and the proximity threshold C includes: measuring the second temperature value A2 of the product inside the refrigeration chamber, comparing the second temperature value A2 with the first proximity threshold C1 and the second proximity threshold C2; A2 < A1; if C2 < A2 ≤ C1, adjusting the liquid nitrogen flow rate of the liquid nitrogen nozzle in the third quick-freezing zone according to the position of the product in the refrigeration chamber; if A2 ≤ C2, the liquid nitrogen flow rate of the liquid nitrogen nozzle remains unchanged; measuring the third temperature value A3 of the product at the outlet, if A3 ≤ C2, the liquid nitrogen flow rate of the liquid nitrogen nozzle at the outlet remains unchanged, if A3 > C2, increasing the liquid nitrogen flow rate of the liquid nitrogen nozzle at the outlet; A3 ≤ A2 < A1.

[0021] Furthermore, the method for adjusting the liquid nitrogen flow rate of the liquid nitrogen nozzle in the third quick-freezing zone according to the product's position in the refrigeration chamber includes: detecting whether the product is located in the third quick-freezing zone through a detection module; if not, reducing the liquid nitrogen flow rate of the liquid nitrogen nozzle in the third quick-freezing zone; if so, increasing the liquid nitrogen flow rate of the liquid nitrogen nozzle in the third quick-freezing zone.

[0022] Beneficial effects:

[0023] 1. By setting up a first refrigeration module and a second refrigeration module, the first refrigeration module continuously provides air cooling to the product in the refrigeration chamber, while the second refrigeration module sprays liquid nitrogen onto the product for cooling. The product entering the refrigeration chamber is pre-cooled by the air cooling provided by the first refrigeration module. The temperature of the product is measured by a detection module. When the product reaches a certain temperature and conditions, the second refrigeration module is activated to perform liquid nitrogen quick-freezing, thus achieving quick-freezing. Through the above-mentioned combined quick-freezing method, the freezing time of slow freezing is relatively reduced, allowing the quick-frozen product to quickly pass through the maximum ice crystal formation zone, ensuring a better quick-freezing effect for the food, accelerating the quick-freezing efficiency, and improving the quality of frozen products. By monitoring the product temperature as the node to activate liquid nitrogen quick-freezing, the cost of rapid freezing is reduced, and product low-temperature breakage is avoided. This solves the technical problems of poor quick-freezing effect and quality of food in related technologies.

[0024] 2. By incorporating a dehumidification system, air is cooled and dehumidified by the dehumidifying evaporator before being delivered to the inlet and outlet by the first and second fans. The first and second air supply channels are perpendicular to the conveyor belt, creating an air curtain that directly blows onto the products at the inlet and outlet. The air then returns to the dehumidifying evaporator through the return air channel. This air curtain effectively isolates the refrigeration chamber from the external environment, preventing heat loss and hindering the entry of water vapor from the outside environment, thus delaying frost formation inside the first and second refrigeration modules. As the products pass through the air curtain at the inlet, residual surface moisture is blown away, reducing the likelihood of product adhesion to the conveyor belt due to frozen surface moisture.

[0025] 3. By setting up multiple quick-freezing zones within the quick-freezing system, each zone is equipped with multiple liquid nitrogen nozzles. The detection module is correspondingly equipped with multiple sensors to detect the temperature or location of each quick-freezing zone, facilitating zone-based temperature or location detection and zone-based quick-freezing temperature management. Based on the real-time feedback from the detection module, the refrigeration parameters of each quick-freezing zone are adjusted in a timely manner to ensure the quick-freezing quality of the product. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the quick-freezing system used in an embodiment of the present invention;

[0027] Figure 2This is a simplified structural diagram of the first and second refrigeration modules of the quick-freezing system used in this embodiment of the invention;

[0028] Figure 3 This is a flowchart of the dehumidification system of the quick-freezing system used in the embodiments of the present invention;

[0029] Figure 4 This is a flowchart of the quick-freezing method used in an embodiment of the present invention.

[0030] The above figures include the following reference numerals:

[0031] 1. Refrigeration chamber; 11. Feed inlet; 12. Discharge outlet; 13. Conveyor belt; 14. Quick-freezing zone; 141. First quick-freezing zone; 142. Second quick-freezing zone; 143. Third quick-freezing zone; 2. First refrigeration module; 21. Refrigeration evaporator; 22. Condenser assembly; 3. Second refrigeration module; 31. Liquid nitrogen storage tank; 32. First pump body; 33. Solenoid valve; 34. Regulating valve; 341. First regulating valve; 342. Second regulating valve 343. Third regulating valve; 344. Fourth regulating valve; 35. Liquid nitrogen nozzle at the discharge port; 4. Liquid nitrogen nozzle; 5. Detection module; 51. Sensor; 6. Dehumidification system; 61. First fan; 611. First air supply channel; 62. Second fan; 621. Second air supply channel; 63. Dehumidifying evaporator; 64. Return air channel; 71. Collection tray; 72. Condensation nozzle; 73. Second pump body; 74. Filter device. Detailed Implementation

[0032] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0033] According to an embodiment of the present invention, a quick-freezing system is provided; please refer to [link / reference]. Figures 1 to 4The system includes: a cooling chamber 1 containing products to be quick-frozen; a first cooling module 2 providing air cooling to the products in the cooling chamber 1; a second cooling module 3 including a liquid nitrogen nozzle 4 for spraying liquid nitrogen onto the products, the liquid nitrogen nozzle 4 being disposed within the cooling chamber 1; a detection module 5 for measuring the temperature of the products; and a control module connected to the detection module 5 and the second cooling module 3; the control module controls the second cooling module 3 to activate based on the temperature of the products. By setting up a first refrigeration module 2 and a second refrigeration module 3, the first refrigeration module 2 continuously provides air cooling to the product in the refrigeration chamber 1, and the second refrigeration module 3 sprays liquid nitrogen onto the product for cooling. The product entering the refrigeration chamber 1 is pre-cooled by the air cooling provided by the first refrigeration module 2. The temperature of the product is measured by the detection module 5. When the product reaches a certain temperature and conditions, the second refrigeration module 3 is activated to perform liquid nitrogen quick-freezing, thus achieving quick-freezing of the product. Through the above-mentioned combined quick-freezing method, the freezing time of slow freezing is relatively reduced, and the quick-frozen product quickly passes through the maximum ice crystal formation zone, ensuring that the food has a better quick-freezing effect, accelerating the quick-freezing efficiency, and improving the quality of frozen products. By monitoring the temperature of the product as the node to start liquid nitrogen quick-freezing, the cost of rapid freezing is reduced, and product low-temperature breakage is avoided. This solves the technical problems of poor quick-freezing effect and quality of food in quick-freezing machines in related technologies.

[0034] In the quick-freezing system of this embodiment, see Figure 1 The quick-freezing system includes: an inlet 11 and an outlet 12, which are connected to a refrigeration chamber 1. The product enters the refrigeration chamber 1 through the inlet 11 and exits through the outlet 12, which is located at the end of the refrigeration chamber 1 furthest from the inlet 11. A conveyor belt 13 passes through the refrigeration chamber 1, carrying the product through both the inlet 11 and outlet 12. The conveyor belt 13 is located below the liquid nitrogen nozzle 4. By setting up the conveyor belt 13, the product is carried through the refrigeration chamber 1 at a uniform speed, achieving uniform cooling of the product.

[0035] Specifically, a conveyor mesh belt is provided on the conveyor belt 13.

[0036] In the quick-freezing system of this embodiment, see Figure 1 and Figure 3The quick-freezing system includes a dehumidification system 6, which includes: a first fan 61, which is connected to the feed inlet 11 through a first air supply channel 611, which is perpendicular to the conveyor belt 13; a second fan 62, which is connected to the discharge outlet 12 through a second air supply channel 621, which is perpendicular to the conveyor belt 13; a dehumidifying evaporator 63, which is connected to both the first fan 61 and the second fan 62, and is used to provide dry air to both the first fan 61 and the second fan 62; and a return air channel 64, which is connected to both the feed inlet 11 and the discharge outlet 12, and the air in the return air channel 64 enters the first fan 61 and the second fan 62 after passing through the dehumidifying evaporator 63. By setting up a dehumidification system 6, air is cooled and dehumidified by the dehumidifying evaporator 63, and then conveyed to the inlet 11 and outlet 12 by the first fan 61 and the second fan 62. The first air supply channel 611 and the second air supply channel 621 are set perpendicular to the conveyor belt 13, so the air forms an air curtain that blows directly onto the product at the inlet 11 and outlet 12, and then returns to the dehumidifying evaporator 63 through the return air channel 64. The formation of the air curtain can effectively isolate the heat exchange between the refrigeration chamber 1 and the external environment, prevent the loss of cooling capacity of the refrigeration chamber 1, and also hinder the entry of water vapor from the external environment, delaying the frost formation inside the first refrigeration module 2 and the second refrigeration module 3. When the product passes through the air curtain at the inlet 11, the air curtain can also blow away the residual moisture on the surface, reducing the possibility of the product sticking to the conveyor belt 13 due to the freezing of moisture on the product surface.

[0037] In the quick-freezing system of this embodiment, see Figure 2 The second refrigeration module 3 includes: a liquid nitrogen storage tank 31 for storing liquid nitrogen; a first pump body 32, one end of which is connected to the liquid nitrogen storage tank 31, and the other end of which is connected to the liquid nitrogen nozzle 4; a solenoid valve 33 located between the first pump body 32 and the liquid nitrogen storage tank 31; and a regulating valve 34 located between the liquid nitrogen nozzle 4 and the first pump body 32, which controls the flow rate of the liquid nitrogen nozzle 4 by adjusting the opening of the regulating valve 34. With the above configuration, the first pump body 32 is used to deliver liquid nitrogen to the liquid nitrogen nozzle 4, and the solenoid valve 33 controls the flow of liquid nitrogen.

[0038] In the quick-freezing system of this embodiment, see Figure 1 The quick-freezing system includes a liquid nitrogen nozzle 35 at the outlet, which is located between the liquid nitrogen nozzle 4 and the outlet 12. By setting the liquid nitrogen nozzle 35 at the outlet, the refrigeration intensity can be adjusted by selecting to open the liquid nitrogen nozzle 35 or adjusting the flow rate of the liquid nitrogen nozzle 35 according to the quick-freezing temperature of the product, so as to ensure the quick-freezing quality of the product.

[0039] In the quick-freezing system of this embodiment, see Figure 1 The quick-freezing system includes multiple quick-freezing zones 14, which are spaced apart within the refrigeration chamber 1 along the extension direction of the conveyor belt 13. Multiple liquid nitrogen nozzles 4 are provided in each of the quick-freezing zones 14. Detection modules 5 are located on both sides of the conveyor belt 13, each module including multiple sensors 51, corresponding to the multiple quick-freezing zones 14. Thus, the sensors 51 can detect the temperature and position information of the product. By setting multiple quick-freezing zones 14 within the quick-freezing system, each equipped with multiple liquid nitrogen nozzles 4, and correspondingly providing multiple sensors 51 for each zone, the system facilitates zoned temperature or position detection and zoned management of the quick-freezing temperature. Based on real-time feedback from the detection modules 5, the refrigeration parameters of each quick-freezing zone 14 can be adjusted promptly to ensure the quality of the quick-frozen product.

[0040] Specifically, sensor 51 is an infrared sensor.

[0041] In the quick-freezing system of this embodiment, see Figure 1 The multiple quick-freezing zones 14 include a first quick-freezing zone 141, a second quick-freezing zone 142 and a third quick-freezing zone 143 arranged at intervals. The first quick-freezing zone 141 is located in the refrigeration chamber 1 on the side close to the feed inlet 11, and the third quick-freezing zone 143 is located in the refrigeration chamber 1 on the side away from the feed inlet 11.

[0042] In the quick-freezing system of this embodiment, see Figure 2 The regulating valve 34 includes: a first regulating valve 341, connected to multiple liquid nitrogen nozzles 4 within the first quick-freezing zone 141; a second regulating valve 342, connected to multiple liquid nitrogen nozzles 4 within the second quick-freezing zone 142; a third regulating valve 343, connected to multiple liquid nitrogen nozzles 4 within the third quick-freezing zone 143; and a fourth regulating valve 344, connected to the liquid nitrogen nozzle 35 at the discharge port. By setting the first regulating valve 341, the second regulating valve 342, the third regulating valve 343, and the fourth regulating valve 344, any one of the above regulating valves can be adjusted individually based on the real-time feedback from the detection module 5, thereby enabling individual adjustment of any quick-freezing zone 14 or the liquid nitrogen nozzle 35 at the discharge port, facilitating zoned management and improving quick-freezing efficiency.

[0043] In the quick-freezing system of this embodiment, see Figure 2 The first refrigeration module 2 includes: a refrigeration evaporator 21, which is used to supply cooling to the first refrigeration module 2; and a condenser assembly 22, which is connected to the refrigeration evaporator 21 and the dehumidifying evaporator 63 respectively to participate in the refrigeration cycle.

[0044] In the quick-freezing system of this embodiment, see Figure 2 The quick-freezing system also includes: a collection tray 71 located below the conveyor belt 13, used to recover liquid nitrogen; a condensing nozzle 72 connected to the collection tray 71, which sprays the liquid nitrogen from the collection tray 71 onto the surface of the condenser assembly 22 to cool it; and a second pump body 73 located between the collection tray 71 and the condensing nozzle 72 to deliver liquid nitrogen into the condensing nozzle 72. Through this configuration, liquid nitrogen leaking from the conveyor belt 13 is recovered through the collection tray 71, and then sprayed onto the surface of the condenser assembly 22 through the condensing nozzle 72. The residual heat of the liquid nitrogen is used to cool the condenser assembly 22, improving its heat exchange efficiency and thus the cooling efficiency of the first refrigeration module 2, achieving resource recovery and avoiding waste.

[0045] In the quick-freezing system of this embodiment, see Figure 2 The quick-freezing system also includes a filter device 74, located between the collection tray 71 and the second pump body 73, for filtering liquid nitrogen. With this setup, the recovered liquid nitrogen is filtered before being sprayed, preventing product residue or other impurities on the conveyor belt from clogging the second pump body 73 and the condenser nozzle 72.

[0046] In the quick-freezing method of this embodiment, see... Figure 4 The above-mentioned quick-freezing system is applicable to the quick-freezing method, which includes: measuring the first temperature value A1 of the product entering the refrigeration chamber 1 through the detection module 5; comparing the value of the first temperature value A1 with the opening threshold B; if A1 > B, then keeping the first refrigeration module 2 open; if A1 ≤ B, then opening the second refrigeration module 3; after a period of time, detecting the temperature value A of the product in the refrigeration chamber 1, comparing the value of A with the proximity threshold C, and controlling the flow rate of liquid nitrogen according to the relationship between A and the proximity threshold C.

[0047] Specifically, the flow rate of liquid nitrogen is controlled by adjusting the opening of the regulating valve 34.

[0048] Specifically, when the product enters the refrigeration chamber 1, it is first pre-cooled by the first refrigeration module 2. When the product passes through the first quick-freezing zone 141, the product temperature A1 is detected. The value of the first temperature A1 is compared with the opening threshold B. If A1 > B, it means that the product is not pre-cooled enough and has not yet reached the maximum ice crystal formation zone. Therefore, the first refrigeration module 2 remains open, allowing the product to continue to receive air cooling. If A1 ≤ B, it means that the product pre-cooling temperature has been reached. At this time, the second refrigeration module 3 can be opened to allow the product to undergo liquid nitrogen quick-freezing. During the operation of the second refrigeration module 3, the temperature A is detected to monitor the quick-freezing temperature of the product and to control the opening of the regulating valve 34 in a timely manner to ensure the quick-freezing effect of the product.

[0049] By detecting the first temperature value A1, it can be determined whether the product meets the pre-cooling temperature, thus enabling the second cooling module 3 to be activated in a timely manner.

[0050] Specifically, the threshold B = 0℃, at which point the food is about to reach the maximum ice crystal formation zone.

[0051] In the quick-freezing method of this embodiment, see... Figure 4 The method for activating the second refrigeration module 3 includes: the second refrigeration module 3 is equipped with a solenoid valve 33 and a first pump body 32; the solenoid valve 33 and the first pump body 32 are opened to extract liquid nitrogen from the liquid nitrogen storage tank 31 located in the second refrigeration module 3.

[0052] In the quick-freezing method of this embodiment, see... Figure 4 The proximity threshold C includes a first proximity threshold C1 and a second proximity threshold C2. A third quick-freezing zone 143 is provided in the refrigeration chamber 1, and a liquid nitrogen nozzle 4 is provided in the third quick-freezing zone 143. The refrigeration chamber 1 includes a liquid nitrogen outlet nozzle 35. The method for controlling the liquid nitrogen flow rate according to the relationship between A and the proximity threshold C includes: measuring the second temperature value A2 of the product in the refrigeration chamber 1, and comparing the second temperature value A2 with the first proximity threshold C1 and the second proximity threshold C2; A2 < A1; if C2 < A2 ≤ C1, adjust the liquid nitrogen flow rate of the liquid nitrogen nozzle 4 in the third quick-freezing zone 143 according to the position of the product in the refrigeration chamber 1; if A2 ≤ C2, the liquid nitrogen flow rate of the liquid nitrogen nozzle 4 remains unchanged; measure the third temperature value A3 of the product located at the outlet 12, if A3 ≤ C2, the liquid nitrogen flow rate of the liquid nitrogen outlet nozzle 35 remains unchanged, if A3 > C2, increase the liquid nitrogen flow rate of the liquid nitrogen outlet nozzle 35; A3 ≤ A2 < A1.

[0053] Specifically, the liquid nitrogen flow rate of the liquid nitrogen nozzle 4 in the third quick-freezing zone 143 is adjusted by adjusting the opening of the third regulating valve 343; the liquid nitrogen flow rate of the liquid nitrogen nozzle 35 at the discharge port is adjusted by the fourth regulating valve 344; if A3≤C2, the fourth regulating valve 344 remains closed, and if A3>C2, the opening of the fourth regulating valve 344 is increased.

[0054] After a period of liquid nitrogen refrigeration, the degree of quick-freezing of the product is detected by measuring the second temperature value A2. If C2 < A2 ≤ C1, it means that the product is about to reach the qualified out-of-warehouse temperature. At this time, the opening of the third regulating valve 343 needs to be adjusted according to the product's position to adjust the liquid nitrogen flow rate of the liquid nitrogen nozzle 4 in the third quick-freezing zone 143, so as to ensure that the product can reach the out-of-warehouse temperature before leaving the warehouse. If A2 ≤ C2, it means that the product temperature has reached the qualified out-of-warehouse temperature and there is no need to increase the refrigeration intensity. Therefore, the liquid nitrogen flow rate of the liquid nitrogen nozzle 4 remains unchanged.

[0055] When the product is about to reach the outlet 12, the third temperature value A3 of the product is detected to determine whether the product has reached the qualified outlet temperature. If A3≤C2, it means that the product has reached the qualified outlet temperature. Therefore, the fourth regulating valve 344 remains closed, and the liquid nitrogen flow rate of the liquid nitrogen nozzle 35 at the outlet remains unchanged. If A3>C2, it means that the product has not yet reached the qualified outlet temperature. Therefore, the opening of the fourth regulating valve 344 is increased, so that the flow rate of the liquid nitrogen nozzle 35 at the outlet is increased, the cooling intensity in this range is increased, the temperature of the product is reduced faster, and the product's outlet temperature is guaranteed to be qualified.

[0056] Specifically, the acceptable temperature for quick-frozen products to leave the warehouse is -18℃.

[0057] Specifically, C1 = -15℃, C2 = -18℃.

[0058] In the quick-freezing method of this embodiment, see... Figure 4 The method for adjusting the liquid nitrogen flow rate of the liquid nitrogen nozzle 4 in the third quick-freezing zone 143 according to the position of the product in the refrigeration chamber 1 includes: detecting whether the product is located in the third quick-freezing zone 143 by the detection module 5; if not, reducing the liquid nitrogen flow rate of the liquid nitrogen nozzle 4 in the third quick-freezing zone 143; if so, increasing the liquid nitrogen flow rate of the liquid nitrogen nozzle 4 in the third quick-freezing zone 143.

[0059] When C2 < A2 ≤ C1, it indicates that the product is about to reach the qualified out-of-warehouse temperature after quick-freezing. At this time, the location of the product is determined. If it is located in the third quick-freezing zone 143, it means that the product is about to leave the refrigeration chamber 1. At this time, the opening of the third regulating valve 343 is increased to increase the liquid nitrogen flow rate of the liquid nitrogen nozzle 4 in the third quick-freezing zone 143, thereby increasing the quick-freezing intensity of the third quick-freezing zone 143 and accelerating the quick-freezing rate of the product. If the product is not located in the third quick-freezing zone 143, the opening of the third regulating valve 343 is reduced to reduce the liquid nitrogen flow rate of the liquid nitrogen nozzle 4 in the third quick-freezing zone 143, in order to save resources and avoid waste.

[0060] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0061] Optionally, specific examples in this embodiment can refer to the examples described in the above embodiments, and will not be repeated here.

[0062] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0063] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0064] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A quick-freezing method, characterized in that, The quick-freezing system includes: A refrigeration chamber (1) contains products to be quick-frozen; The first refrigeration module (2) is used to provide air cooling to the product in the refrigeration chamber (1); The second refrigeration module (3) includes a liquid nitrogen nozzle (4) for spraying liquid nitrogen onto the product, and the liquid nitrogen nozzle (4) is disposed inside the refrigeration chamber (1). The detection module (5) is used to measure the temperature of the product; The control module is signal-connected to the detection module (5) and to the second refrigeration module (3); the control module controls the second refrigeration module (3) to turn on according to the temperature of the product. The inlet (11) and outlet (12) are respectively connected to the refrigeration chamber (1). The product enters the refrigeration chamber (1) through the inlet (11) and leaves the refrigeration chamber (1) through the outlet (12). A conveyor belt (13) passes through the refrigeration chamber (1) and carries the product through the inlet (11) and the outlet (12) respectively. The quick-freezing system includes multiple quick-freezing zones (14), which are spaced apart in the refrigeration chamber (1) along the extension direction of the conveyor belt (13). The liquid nitrogen nozzle (4) includes multiple nozzles, and each of the multiple quick-freezing zones (14) is provided with multiple liquid nitrogen nozzles (4); the refrigeration chamber (1) includes a discharge port liquid nitrogen nozzle (35). The detection module (5) is provided on both sides of the conveyor belt (13). The detection module (5) includes multiple sensors (51), and the multiple sensors (51) are provided for multiple quick-freezing zones (14). The plurality of quick-freezing zones (14) include a first quick-freezing zone (141), a second quick-freezing zone (142) and a third quick-freezing zone (143) arranged at intervals. The first quick-freezing zone (141) is located in the refrigeration chamber (1) on the side close to the feed inlet (11), and the third quick-freezing zone (143) is located in the refrigeration chamber (1) on the side away from the feed inlet (11). The quick-freezing method includes: When the product enters the refrigeration chamber 1, it is first pre-cooled by the first refrigeration module 2. When the product passes through the first quick-freezing zone of multiple quick-freezing zones (14), the temperature A1 of the product is detected by the detection module (5). The value of the first temperature value A1 is compared with the opening threshold B. If A1 > B, the first refrigeration module (2) is kept open; if A1 ≤ B, the second refrigeration module (3) is opened. After a period of time, the temperature value A of the product in the refrigeration chamber (1) is detected, and the value of A is compared with the proximity threshold C. Based on the relationship between A and the proximity threshold C, the flow rate of liquid nitrogen is controlled. The proximity threshold includes a first proximity threshold C1 and a second proximity threshold C2. Based on the relationship between A and the proximity threshold C, methods for controlling the flow rate of liquid nitrogen include: Measure the second temperature value A2 of the product in the cooling chamber (1), and compare the second temperature value A2 with the first proximity threshold C1 and the second proximity threshold C2; A2 < A1; If C2 < A2 ≤ C1, adjust the liquid nitrogen flow rate of the liquid nitrogen nozzle (4) in the third quick-freezing zone (143) according to the position of the product in the refrigeration chamber (1); If A2≤C2, then the liquid nitrogen flow rate of the liquid nitrogen nozzle (4) in the third quick-freezing zone remains unchanged; The method for adjusting the liquid nitrogen flow rate of the liquid nitrogen nozzle (4) in the third quick-freezing zone (143) according to the position of the product in the refrigeration chamber (1) includes: The detection module (5) detects whether the product is located in the third quick-freezing zone (143). If not, reduce the liquid nitrogen flow rate of the liquid nitrogen nozzle (4) in the third quick-freezing zone (143); If so, increase the liquid nitrogen flow rate of the liquid nitrogen nozzle (4) in the third quick-freezing zone (143); Measure the third temperature value A3 of the product located at the outlet (12). If A3≤C2, the liquid nitrogen flow rate of the liquid nitrogen nozzle (35) at the outlet remains unchanged. If A3>C2, the liquid nitrogen flow rate of the liquid nitrogen nozzle (35) at the outlet is increased. A3≤A2<A1.

2. The quick-freezing method according to claim 1, characterized in that, The discharge port (12) is located at one end of the refrigeration chamber (1) away from the inlet (11); The conveyor belt (13) is located below the liquid nitrogen nozzle (4).

3. The quick-freezing method according to claim 2, characterized in that, The quick-freezing system includes a dehumidification system (6), which includes: The first fan (61) is connected to the feed inlet (11) through the first air supply channel (611), and the first air supply channel (611) is perpendicular to the conveyor belt (13). The second fan (62) is connected to the discharge port (12) through the second air supply channel (621), and the second air supply channel (621) is perpendicular to the conveyor belt (13). A dehumidifying evaporator (63) is connected to the first fan (61) and the second fan (62) respectively, and is used to provide dry air to the first fan (61) and the second fan (62); The return air duct (64) is connected to the feed inlet (11) and the discharge outlet (12) respectively. The air in the return air duct (64) enters the first fan (61) and the second fan (62) through the dehumidifying evaporator (63).

4. The quick-freezing method according to claim 2, characterized in that, The second refrigeration module (3) includes: Liquid nitrogen storage tank (31), said liquid nitrogen storage tank (31) is used to store liquid nitrogen; The first pump body (32) has one end connected to the liquid nitrogen storage tank (31) and the other end connected to the liquid nitrogen nozzle (4). Solenoid valve (33), the solenoid valve (33) is located between the first pump body (32) and the liquid nitrogen storage tank (31); A regulating valve (34) is located between the liquid nitrogen nozzle (4) and the first pump body (32). The flow rate of the liquid nitrogen nozzle (4) is controlled by adjusting the opening degree of the regulating valve (34).

5. The quick-freezing method according to claim 4, characterized in that, The quick-freezing system includes a liquid nitrogen nozzle (35) at the discharge port, which is located between the liquid nitrogen nozzle (4) and the discharge port (12).

6. The quick-freezing method according to claim 4, characterized in that, The regulating valve (34) includes: A first regulating valve (341) is connected to a plurality of liquid nitrogen nozzles (4) within the first quick-freezing zone (141); The second regulating valve (342) is connected to the plurality of liquid nitrogen nozzles (4) in the second quick-freezing zone (142); The third regulating valve (343) is connected to a plurality of liquid nitrogen nozzles (4) in the third quick-freezing zone (143); The fourth regulating valve (344) is connected to the liquid nitrogen nozzle (35) at the discharge port.

7. The quick-freezing method according to claim 3, characterized in that, The first refrigeration module (2) includes: A refrigeration evaporator (21) is used to supply cooling to the first refrigeration module (2); A condenser assembly (22) is connected to the refrigeration evaporator (21) and the dehumidification evaporator (63) respectively to participate in the refrigeration cycle.

8. The quick-freezing method according to claim 7, characterized in that, The quick-freezing system also includes: A collection tray (71) is located below the conveyor belt (13) and is used to recover the liquid nitrogen; A condensing nozzle (72) is connected to the collection tray (71). The condensing nozzle (72) sprays the liquid nitrogen in the collection tray (71) onto the surface of the condenser assembly (22) to cool the condenser assembly (22). The second pump body (73) is located between the collection plate (71) and the condensation nozzle (72) for conveying the liquid nitrogen into the condensation nozzle (72).

9. The quick-freezing method according to claim 8, characterized in that, The quick-freezing system also includes a filter device (74) located between the collection tray (71) and the second pump body (73) for filtering the liquid nitrogen.

10. The quick-freezing method according to claim 1, characterized in that, The method of opening the second refrigeration module (3) includes: the second refrigeration module (3) is provided with a solenoid valve (33) and a first pump body (32), the solenoid valve (33) and the first pump body (32) are opened, and liquid nitrogen is extracted from the liquid nitrogen storage tank (31) located in the second refrigeration module (3).

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