Quick freezer and control method of quick freezer

Abstract

The application discloses a quick freezer and a control method of the quick freezer. The quick freezer comprises multiple function rooms, a conveying belt for conveying articles through each function room, and a refrigerating unit. The multiple function rooms comprise a precooling room and a quick freezing room. The precooling room and the quick freezing room are communicated. A quick freezing air cooler is installed in the quick freezing room. Air discharged from the quick freezing room is sent back to the quick freezing room through the precooling room. The precooling room is divided into at least two precooling chambers. Each precooling chamber is provided with a precooling air cooler capable of working independently. When the quick freezer is in a refrigeration state, the precooling air cooler of at least one precooling chamber is in refrigeration operation, and the air inlet and the air outlet of the precooling chamber are both opened. According to the application, the air sent into the quick freezing room is dehumidified in advance by the precooling air cooler, so that the quick freezing air cooler in the quick freezing room is frost-free. The precooling air cooler in the precooling room alternately performs refrigeration and defrosting, and the quick freezer realizes frost-free defrosting without stopping.

Description

Technical Field

[0001] This invention relates to the field of quick-freezing technology, and more particularly to quick-freezing machines and control methods for quick-freezing machines. Background Technology

[0002] A quick-freezing machine is a device used for rapidly freezing food or goods. A traditional quick-freezing machine typically consists of a refrigeration unit, a freezing chamber, and a conveyor belt. The refrigeration system provides cooling to the freezing chamber. The refrigeration unit usually includes components such as a compressor, condenser, and evaporator, which compresses and condenses liquid refrigerant into a solid state. The evaporator then transfers heat to the air, thereby lowering the temperature of the freezing chamber. The conveyor belt transports the items to be frozen through the freezing chamber, which freezes the items on the conveyor belt. The freezing chamber is usually made of insulation material to maintain a low-temperature environment.

[0003] Because the quick-freezing room is in a low-temperature environment for a long time, the frost on the surface of the evaporator will be accelerated when the high-humidity air flows through the evaporator. An excessively thick frost layer will seriously hinder the heat exchange between the evaporator and the air, requiring the evaporator to be stopped frequently for defrosting, which will affect the production efficiency of the quick-freezing machine.

[0004] Therefore, how to design a quick-freezing machine that can achieve defrosting without stopping and the control method of the quick-freezing machine are technical problems that the industry urgently needs to solve. Summary of the Invention

[0005] To address the problem of existing quick-freezing machines requiring frequent shutdowns for defrosting, this invention proposes a quick-freezing machine and its control method. By using a pre-cooling air cooler to pre-dehumidify the air supplied to the quick-freezing chamber, the quick-freezing air cooler in the quick-freezing chamber becomes frost-free. The pre-cooling air cooler in the pre-cooling chamber alternates between cooling and defrosting, enabling the quick-freezing machine to defrost without stopping.

[0006] The technical solution adopted in this invention is to design a quick-freezing machine, including: multiple functional rooms, conveyor belts for transporting goods through each of the functional rooms, and a refrigeration unit; the multiple functional rooms include a pre-cooling room and a quick-freezing room, the pre-cooling room and the quick-freezing room are connected, a quick-freezing air cooler is installed in the quick-freezing room, and the air outlet of the quick-freezing room is sent back to the quick-freezing room through the pre-cooling room; the pre-cooling room is divided into at least two pre-cooling chambers, and each pre-cooling chamber is equipped with a pre-cooling air cooler that can work independently.

[0007] Furthermore, the air inlet of the precooling chamber is connected to the air outlet of the quick-freezing room, and the air outlet of the precooling chamber is connected to the air inlet of the quick-freezing room.

[0008] When the precooling air cooler is in the defrosting state, both the air inlet and air outlet of the precooling chamber where the precooling air cooler is located are closed;

[0009] When the quick-freezing machine is in refrigeration mode, at least one pre-cooling chamber's pre-cooling fan is in refrigeration operation, and both the air inlet and outlet of the pre-cooling chamber are open.

[0010] Furthermore, the air inlet of the precooling chamber is equipped with an inlet air valve to control its on / off state; the air outlet of the precooling chamber is equipped with an outlet air valve to control its on / off state.

[0011] Furthermore, the quick-freezing room is provided with an air supply duct and an air outlet duct. The air supply duct is connected to the air outlet of the pre-cooling chamber, and the air outlet duct is connected to the air inlet of the pre-cooling chamber. The conveyor belt has a pre-cooling conveying section that passes through the pre-cooling room. The pre-cooling conveying section is located between the air outlet duct and the air inlet of the pre-cooling chamber.

[0012] Furthermore, the plurality of functional rooms include a dehumidification room, a precooling room, and a quick-freezing room arranged sequentially along the direction of goods transport. The dehumidification room is separated from the precooling room, and the dehumidification room is equipped with a dehumidifying air cooler connected to the refrigeration unit.

[0013] Furthermore, the air coolers for each function are connected in parallel to the refrigerant circulation loop of the refrigeration unit, and each air cooler is equipped with a throttling valve on its inlet side.

[0014] The present invention also proposes a control method for a quick-freezing machine, the control method being applied to the aforementioned quick-freezing machine, comprising: after turning on the pre-cooling air blower in the pre-cooling room, determining whether a pre-cooling air blower has reached the defrosting entry condition;

[0015] If so, close the air inlet and outlet of the precooling chamber where the precooling air cooler is located, and defrost the precooling air cooler;

[0016] If not, the pre-cooling air cooler continues to operate.

[0017] Furthermore, control methods also include:

[0018] The defrosting priority of each pre-cooled air cooler is preset. After it is determined that a pre-cooled air cooler has reached the defrosting entry condition, it is determined whether all pre-cooled air coolers have reached the defrosting entry condition.

[0019] If so, the pre-cooling air conditioners are defrosted according to their defrosting priority, and at least one pre-cooling air conditioner is in cooling operation.

[0020] If not, the pre-cooling air cooler that has not met the defrosting conditions will continue to operate in cooling mode.

[0021] Furthermore, the control method also includes: upon receiving a refrigeration start-up command, starting the refrigeration unit, turning on the dehumidifying air cooler in the dehumidification room and the pre-cooling air cooler in the pre-cooling room; when T is detected...预冷 ≤T0 and T 速冻 When T1 is less than or equal to 1, turn on the quick-freezing air cooler in the quick-freezing room;

[0022] Among them, T 预冷 T represents the internal temperature of the pre-cooling room. 速冻 The temperature inside the quick-freezing room is T0, and T1 is a set temperature.

[0023] Furthermore, control methods also include:

[0024] After the air cooler in any of the aforementioned functional rooms is turned on, the evaporation temperature of the air cooler in that functional room is detected and the temperature difference between the evaporation temperature and the corresponding target evaporation temperature is calculated.

[0025] Adjust the opening of the throttle valve of the air cooler according to the temperature difference.

[0026] Furthermore, the change in the throttle valve opening Δu k for:

[0027] Δu k =K p ×(e k -e k-1 )+K i ×e k +K d ×(e k -2×e k-1 +e k-2 );

[0028] Among them, K p K is the proportionality coefficient. i K is the integration time constant. d e is the differential time constant. k e represents the temperature difference between the evaporation temperature of the air cooler detected in the kth sampling period and its corresponding target evaporation temperature. k-1 e is the temperature difference between the evaporation temperature of the air cooler detected in the (k-1)th sampling period and its corresponding target evaporation temperature. k-2 This is the temperature difference between the evaporation temperature of the air cooler detected in the (k-2)th sampling period and its corresponding target evaporation temperature.

[0029] Furthermore, control methods also include:

[0030] After the pre-cooling air cooler is turned on, the humidity parameters of the pre-cooling room and the quick-freezing room are detected;

[0031] When ψ 预冷 ≥C1 or ψ 速冻 When ≥C2, according to ψ 预冷 The difference between C1 and C2 is used to adjust the speed of the pre-cooling air cooler;

[0032] When ψ 预冷 <C1 and ψ 速冻 When <C2, the pre-cooling air cooler operates at the set maximum speed V0;

[0033] Where, ψ 预冷 ψ represents the humidity inside the pre-cooling room. 速冻 C1 is the target humidity of the quick-freezing room, C2 is the target humidity of the pre-cooling room, and C3 is the target humidity of the quick-freezing room.

[0034] Furthermore, according to ψ 预冷 Adjusting the speed of the pre-cooling air cooler by the difference between C1 and C1 includes:

[0035] V=V0-K1×(ψ 预冷 -C1);

[0036] Wherein, V is the rotational speed of the pre-cooling air cooler, K1 is the set coefficient, and V0 is the set maximum rotational speed of the pre-cooling air cooler.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. The air outlet of the quick-freezing room is sent back to the quick-freezing room through the pre-cooling room. The pre-cooling air cooler in the pre-cooling room dehumidifies the return air, reducing the humidity in the quick-freezing room. This makes the quick-freezing air cooler in the quick-freezing room frost-free. The pre-cooling air cooler in the pre-cooling room alternates between cooling and defrosting. The quick-freezing machine does not need to be stopped for defrosting, which significantly improves production efficiency.

[0039] 2. The air inlet and outlet of the defrosting precooling chamber are closed, while the air inlet of the normal precooling chamber is open. This ensures that the defrosting process does not affect the airflow circulation between the quick-freezing chamber and the normal precooling chamber, thus guaranteeing efficient heat exchange in the precooling chamber and improving the unit's cooling effect.

[0040] 3. The design includes a dehumidification room, a pre-cooling room, and a quick-freezing room arranged in sequence. The dehumidification room removes moisture from the items and performs initial pre-cooling. The quick-freezing room sends low-temperature cold air to the pre-cooling room for secondary pre-cooling of the items, avoiding excessive cooling of moisture in the quick-freezing room, reducing the energy consumption of the quick-freezing machine, and improving the quick-freezing efficiency.

[0041] 4. By controlling the alternating cooling and defrosting of the pre-cooling air cooler, the quick-freezing machine can be defrosted without stopping, ensuring efficient heat exchange in the pre-cooling room;

[0042] 5. The opening of the throttle valve is precisely controlled according to the temperature inside each functional room, so that the evaporation temperature of the air cooler is close to the corresponding target evaporation temperature, preventing the air cooler from frosting and ensuring heat exchange efficiency.

[0043] 6. Adjust the speed of the pre-cooling air cooler according to the environment inside the pre-cooling room and quick-freezing room. When the humidity in the pre-cooling room and / or quick-freezing room is high, reduce the speed to increase the dehumidification capacity. When the humidity in the pre-cooling room and quick-freezing room is low, control the pre-cooling air cooler to run at the set maximum speed V0 to achieve the maximum heat exchange efficiency of the refrigeration unit. Attached Figure Description

[0044] The present invention will now be described in detail with reference to the embodiments and accompanying drawings, wherein:

[0045] Figure 1 This is a connection diagram of the quick-freezing machine of the present invention;

[0046] Figure 2 This is a schematic diagram of the defrosting control of the pre-cooling air cooler of the present invention;

[0047] Figure 3 This is a schematic diagram of the alternating defrosting control of the pre-cooling air cooler of the present invention;

[0048] Figure 4 This is a schematic diagram of the start-up control of the refrigeration unit of the present invention;

[0049] Figure 5 This is a schematic diagram of the wind speed control of the pre-cooling air cooler of the present invention;

[0050] Figure label:

[0051] 1. Compressor; 2. Condenser; 3. Quick-freezing throttling valve; 4. Pre-cooling throttling valve; 5. Dehumidifying throttling valve; 6. First switching valve; 7. Second switching valve; 8. Pre-cooling chamber evaporating pressure balancing valve; 9. Dehumidifying chamber evaporating pressure balancing valve; 10. First inlet air valve; 11. First outlet air valve; 12. Second inlet air valve; 13. Second outlet air valve; 14. Dehumidifying air cooler; 15. First pre-cooling air cooler; 16. Second pre-cooling air cooler; 17. Quick-freezing air cooler; 18. Conveyor belt; 19. Dehumidifying chamber; 20. Pre-cooling chamber; 201. First pre-cooling chamber; 202. Second pre-cooling chamber; 21. Quick-freezing chamber; 22. Supply air duct; 23. Discharge air duct. Detailed Implementation

[0052] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0053] like Figure 1As shown, the quick-freezing machine proposed in this invention includes: multiple functional rooms, a conveyor belt 18, and a refrigeration unit. The conveyor belt 18 transports items through the various functional rooms. The refrigeration unit provides cooling capacity to the air cooler. The refrigeration unit includes a compressor 1, a condenser 2, a throttling valve, and an evaporator, forming a refrigerant circulation loop. The heat exchange tubes of the air cooler participate in the refrigerant circulation of the refrigeration unit as an evaporator. It should be understood that the term "items" mentioned herein includes, but is not limited to, food, and the term "multiple" refers to at least two items.

[0054] The multi-functional room includes a pre-cooling room 20 and a quick-freezing room 21. A conveyor belt 18 transports goods through both the pre-cooling room 20 and the quick-freezing room 21. The quick-freezing room 21 provides a low-temperature environment and is equipped with a quick-freezing air cooler 17. The quick-freezing air cooler 17 blows low-temperature cold air onto the conveyor belt 18 to quickly freeze the goods on the conveyor belt 18. The pre-cooling room 20 and the quick-freezing room 21 are connected; the air outlet of the quick-freezing room 21 is returned to the quick-freezing room 21 via the pre-cooling room 20. The pre-cooling room 20 dehumidifies the airflow from the quick-freezing room 21 and pre-cools the goods. The goods are pre-cooled in the pre-cooling room 20 and then absorb the cold air from the quick-freezing room 21 to achieve quick-freezing. This invention utilizes the pre-cooling air cooler in the pre-cooling room 20 to dehumidify the return air, reducing the humidity inside the quick-freezing room 21 and ensuring that the quick-freezing air cooler 17 inside the quick-freezing room 21 is frost-free.

[0055] The precooling room 20 is divided into at least two precooling chambers, each of which is equipped with an independent precooling air cooler. Each precooling air cooler can independently participate in the refrigerant circulation of the refrigeration unit. That is, during the operation of the blast freezer, the number of precooling air coolers that can be turned on for refrigeration can be selected according to actual needs. For example, all precooling air coolers can be turned on for refrigeration at the same time, or only one precooling air cooler can be turned on for refrigeration. The advantage of designing independent precooling chambers and precooling air coolers is that they can alternate between refrigeration and defrosting, ensuring heat exchange efficiency, and the blast freezer does not need to be stopped for defrosting.

[0056] Specifically, the air inlet of the pre-cooling chamber is connected to the air outlet of the quick-freezing room 21, and the air outlet of the pre-cooling chamber is connected to the air inlet of the quick-freezing room 21. The air from the quick-freezing room 21 enters the pre-cooling chamber and is cooled and dehumidified by the pre-cooling air cooler before being sent back to the quick-freezing room 21.

[0057] For ease of distinction and description, the precooling chamber in which the precooling air cooler is in defrosting state is called the defrosting precooling chamber, and the precooling chamber in which the precooling air cooler is in cooling state is called the normal precooling chamber. The air inlet and outlet of the defrosting precooling chamber are closed, while the air inlet and outlet of the normal precooling chamber are open. This ensures that the defrosting action does not affect the airflow circulation between the quick-freezing chamber 21 and the normal precooling chamber, thus guaranteeing efficient heat exchange in the precooling chamber 20 and improving the unit's cooling effect.

[0058] It should be noted that when the blast freezer is in refrigeration mode, at least one precooling chamber's precooling fan is in refrigeration operation, and both the air inlet and outlet of the precooling chamber are open. That is, at least one of the precooling chambers is in normal operation, in order to ensure that the blast freezer can continue to produce.

[0059] In some embodiments of the present invention, the air inlet of the precooling chamber is equipped with an inlet air valve that controls its on / off state, and the air outlet of the precooling chamber is equipped with an outlet air valve that controls its on / off state. The inlet air valve and the outlet air valve are controlled by the controller of the quick-freezing machine. When the precooling air cooler is in the refrigeration state, the inlet air valve and the outlet air valve are automatically opened, and when the precooling air cooler is in the defrosting state, the inlet air valve and the outlet air valve are automatically closed.

[0060] In some embodiments of the present invention, the quick-freezing room 21 is provided with an air supply duct 22 and an air outlet duct 23. The air outlet duct 23 connects the air outlet of the quick-freezing room 21 and the air inlet of the pre-cooling chamber, and the air supply duct 22 connects the air inlet of the quick-freezing room 21 and the air outlet of the pre-cooling chamber. The conveyor belt 18 has a pre-cooling conveyor section passing through the pre-cooling room 20 and a quick-freezing conveyor section passing through the quick-freezing room 21. The pre-cooling conveyor section is located between the air outlet duct 23 and the air inlet of the pre-cooling chamber. The low-temperature cold air blown out by the quick-freezing air cooler 17 enters the air outlet duct 23 through the quick-freezing conveyor section. The low-temperature cold air delivered by the air outlet duct 23 then passes through the pre-cooling conveyor section to pre-cool the items and then enters the pre-cooling chamber. After being dehumidified and cooled by the pre-cooling air cooler, the dry air is sent back to the quick-freezing room 21.

[0061] Specifically, in one application scenario of the present invention, the upper part of the quick-freezing room 21 is provided with an air supply duct 22, and the lower part of the quick-freezing room 21 is provided with an air outlet duct 23. The conveyor belt 18 is located at the lower part of the quick-freezing machine to facilitate the staff to pick up and take items. Moreover, the cold air blown out by the quick-freezing cold air fan 17 sinks to the air outlet duct 23 located below the conveyor belt 18, and is then drawn upward by the pre-cooling cold air fan to the pre-cooling conveyor section passing through the conveyor belt 18 and entering the pre-cooling chamber. The air circulation is smooth and the pre-cooling effect is better.

[0062] In some embodiments of the present invention, the multiple functional rooms include a dehumidification room 19, a pre-cooling room 20, and a quick-freezing room 21 arranged sequentially along the direction of item transport. The items transported by the conveyor belt 18 first pass through the dehumidification room 19, then through the pre-cooling room 20, and finally through the quick-freezing room 21. The dehumidification room 19 and the pre-cooling room 20 are separated, that is, except for the conveyor belt 18, the other areas between the dehumidification room 19 and the pre-cooling room 20 are not connected, so as to prevent the hot and humid air in the dehumidification room 19 from entering the pre-cooling room 20 and causing the frost situation in the pre-cooling room 20 to worsen.

[0063] The dehumidification room 19 is equipped with a dehumidifying air cooler 14 connected to the refrigeration unit. The dehumidifying air cooler 14 removes moisture from the items using high-speed airflow. Specifically, the dehumidifying air cooler 14 accelerates the airflow to achieve a certain airflow speed and pressure, using this airflow to blow off or dry water droplets on the surface of the items, preventing the quick-freezing room 21 from cooling too much moisture and reducing the energy consumption of the quick-freezing machine. Furthermore, the cold air provided by the dehumidifying air cooler 14 can pre-cool the items initially, and then the low-temperature cold air sent from the quick-freezing room 21 to the pre-cooling room 20 performs a second pre-cooling. After these two pre-cooling processes, the items are sent to the quick-freezing room 21, significantly improving the quick-freezing efficiency.

[0064] In some embodiments of the present invention, the air coolers in each functional room are connected in parallel to the refrigerant circulation loop of the refrigeration unit. Each air cooler is equipped with a throttling valve on its inlet side. All pre-cooling air coolers in the pre-cooling room can share a single throttling valve. Both the air coolers and the throttling valve are controlled by the controller of the quick-freezing machine. The controller independently adjusts the evaporation temperature of its corresponding air cooler through the throttling valve and independently adjusts the airflow speed of its functional room through the air cooler to accurately match the usage requirements of different functional rooms.

[0065] like Figure 1 As shown, specifically, in one application scenario of the present invention, the quick-freezing machine has a dehumidification room 19, a pre-cooling room 20, and a quick-freezing room 21. The pre-cooling room 20 is divided into a first pre-cooling chamber 201 and a second pre-cooling chamber 202. A first pre-cooling air cooler 15 is installed in the first pre-cooling chamber 201, and a second pre-cooling air cooler 16 is installed in the second pre-cooling chamber 202. A dehumidification throttling valve 5 is installed on the inlet side of the dehumidification air cooler 14, and a dehumidification chamber evaporation pressure balancing valve 9 is installed on the outlet side of the dehumidification air cooler 14. The first pre-cooling air cooler 15 and the second pre-cooling air cooler 16 share a pre-cooling throttling valve 4 and a... The precooling chamber evaporation pressure balancing valve 8 is connected to the outlet of the precooling throttling valve 4 via the inlet side of the first precooling air cooler 15 through the first switching valve 6. The inlet side of the second precooling air cooler 16 is connected to the outlet of the precooling throttling valve 4 via the second switching valve 7. The outlet side of the first precooling air cooler 15 and the outlet side of the second precooling air cooler 16 are connected in parallel to the precooling chamber evaporation pressure balancing valve 8. The quick-freezing throttling valve 3 is installed on the inlet side of the quick-freezing air cooler 17. The dehumidification throttling valve 5, the precooling throttling valve 4 and the quick-freezing throttling valve 3 are all connected to the outlet of the condenser 2. The switching valves and throttling valves are all controlled by the controller of the quick-freezing machine.

[0066] In addition, the functional room is provided with an insulation layer around it to maintain a low temperature environment and prevent cold leakage. The insulation layer can be provided on the inner wall surface of the functional room, or on the outer wall surface of the functional room, or embedded in the wall of the functional room. The present invention does not make any special requirements on the installation position of the insulation layer.

[0067] like Figure 2As shown, this invention also proposes a control method for a quick-freezing machine. The controller of the quick-freezing machine executes this control method, and the control logic is as follows:

[0068] After turning on the precooling air cooler in the precooling room, determine whether any precooling air cooler meets the defrosting entry conditions.

[0069] If so, close the air inlet and outlet of the precooling chamber where the precooling air cooler is located, and defrost the precooling air cooler;

[0070] If not, the pre-cooling air cooler will continue to operate.

[0071] For ease of distinction and description, a pre-cooling air conditioner that meets the defrosting entry conditions is called a defrosting pre-cooling air conditioner, and the pre-cooling chamber where the defrosting pre-cooling air conditioner is located is called the defrosting pre-cooling chamber. A pre-cooling air conditioner that does not meet the defrosting entry conditions is called a normal pre-cooling air conditioner, and the pre-cooling chamber where the normal pre-cooling air conditioner is located is called the normal pre-cooling air conditioner. After the pre-cooling air conditioners in the pre-cooling room are turned on, if there are defrosting pre-cooling air conditioners, the air inlet and outlet of the defrosting pre-cooling chamber should be closed, while the air inlet and outlet of the normal pre-cooling chamber should remain open, so that the defrosting action does not affect the airflow circulation between the quick-freezing room and the normal pre-cooling chamber.

[0072] like Figure 3 As shown, in some embodiments of the present invention, the preferred scheme of the defrosting logic is as follows:

[0073] The defrosting priority of each pre-cooled air cooler is preset. After determining that a pre-cooled air cooler has reached the defrosting entry condition, it is determined whether all pre-cooled air coolers have reached the defrosting entry condition.

[0074] If so, the pre-cooling air conditioners will be defrosted in order of defrosting priority, and at least one pre-cooling air conditioner will be running in cooling mode.

[0075] If not, the pre-cooling air coolers that meet the defrosting entry conditions will defrost, while the pre-cooling air coolers that do not meet the defrosting entry conditions will continue to operate in cooling mode.

[0076] The advantage of this design is that it controls the alternating cooling and defrosting of the pre-cooling air cooler, enabling the quick-freezing machine to defrost without stopping, and ensuring efficient heat exchange in the pre-cooling room.

[0077] like Figure 1As shown, for ease of understanding, two pre-cooling air coolers are used as an example. The defrosting priority of the first pre-cooling air cooler 15 is higher than that of the second pre-cooling air cooler 16. When only the first pre-cooling air cooler 15 meets the defrosting entry conditions, the first pre-cooling air cooler 15 enters defrosting, and both the first inlet air valve 10 and the first outlet air valve 11 are closed. When only the second pre-cooling air cooler 16 meets the defrosting entry conditions, the second pre-cooling air cooler 16 enters defrosting, and both the second inlet air valve 12 and the second outlet air valve 13 are closed. When both the first pre-cooling air cooler 15 and the second pre-cooling air cooler 16 meet the defrosting entry conditions simultaneously, the first pre-cooling air cooler 15 defrosts first, and the second pre-cooling air cooler 16 defrosts after the first pre-cooling air cooler 15 has completed defrosting.

[0078] It should be noted that when the pre-cooling air cooler is turned on, the air inlet and outlet of its pre-cooling chamber are already open by default. When the blast freezer is in cooling mode, and the defrosting pre-cooling air cooler reaches the defrosting exit condition, the defrosting pre-cooling air cooler will return to normal pre-cooling air cooler operation, that is, resume cooling operation, and the inlet and outlet air valves of the corresponding pre-cooling chamber will be opened.

[0079] Furthermore, the defrosting entry conditions, defrosting actions, and defrosting exit conditions are all mature existing technologies. For example, the defrosting entry condition can be set by the cooling duration of the pre-cooled air cooler reaching a set duration, or by the frost thickness on the heat exchanger tube surface of the pre-cooled air cooler reaching a set thickness. The defrosting exit condition can be set by the defrosting duration of the defrosting action reaching a set defrosting time. Defrosting methods such as hot air bypass, electric heating, or water defrosting can be used to defrost the pre-cooled air cooler. In practical applications, the corresponding defrosting entry conditions, defrosting actions, and defrosting exit conditions are selected according to specific usage requirements. This invention does not impose any special limitations on these aspects.

[0080] like Figure 1 As shown, in a preferred embodiment of the present invention, the quick-freezing machine has a dehumidification room 19, a pre-cooling room 20 and a quick-freezing room 21. The pre-cooling room 20 is divided into at least two pre-cooling chambers. The start-up phase of the refrigeration unit and the control logic after start-up are described in detail below.

[0081] like Figure 4 As shown, the control process during the start-up phase of the refrigeration unit includes:

[0082] After the refrigeration unit is powered on, the temperature and humidity parameters of the dehumidification room 19, the precooling room 20 and the quick-freezing room 21 are monitored in real time.

[0083] When the refrigeration unit receives the refrigeration start command, the refrigeration unit is turned on, and the dehumidification air cooler 14 in the dehumidification room 19 and the pre-cooling air cooler in the pre-cooling room 20 are turned on.

[0084] When T is detected 预冷 ≤T0 and T 速冻When T1 is less than or equal to 1, turn on the quick-freezing air cooler 17 of quick-freezing room 21.

[0085] Among them, T 预冷 The temperature inside the pre-cooling room is 20℃, T 速冻 T0 and T1 are the internal temperatures of the quick-freezing room 21.

[0086] The purpose of this design is to first use the pre-cooling air cooler to dehumidify and cool the air in the pre-cooling room 20 and the quick-freezing room 21. After the temperature in the pre-cooling room 20 and the quick-freezing room 21 is reduced to the corresponding set temperature, that is, after the airflow is relatively dry, the quick-freezing air cooler 17 is turned on to ensure that the quick-freezing air cooler 17 in the quick-freezing room 21 is frost-free.

[0087] To improve the stability of the quick-freezing machine's startup, the preferred solution is that when the refrigeration unit receives the refrigeration start-up command, it first opens both the inlet and outlet air valves of the pre-cooling chamber simultaneously, with a delay of t. 延时0 After a certain time, ensuring the airflow channels are clear, turn on the dehumidifying air cooler 14, the pre-cooling air cooler, the quick-freezing air cooler 17, and the expansion valve, delaying for t seconds. 延时1 After a certain period of time, ensuring the refrigerant passage is clear, start compressor 1. 延时0 and t 延时1 All of these are preset delay times, the length of which can be designed according to actual usage requirements, for example, t 延时0 For 60 seconds, t 延时1 It lasts for 20 seconds.

[0088] like Figure 4 As shown, the control process after the refrigeration unit starts up includes:

[0089] After the air cooler in any functional room is turned on, the evaporation temperature of the air cooler in that functional room is detected and the temperature difference between the evaporation temperature and the corresponding target evaporation temperature is calculated.

[0090] Adjust the opening of the throttle valve of the air cooler according to the temperature difference.

[0091] The purpose of this design is to precisely control the opening of the throttle valve according to the temperature inside each functional compartment, so that the evaporation temperature of the air cooler approaches the corresponding target evaporation temperature, preventing the air cooler from frosting and ensuring heat exchange efficiency.

[0092] Specifically, the change in the throttle valve opening Δu k for:

[0093] Δu k =K p ×(e k -e k-1 )+K i ×e k +K d ×(ek -2×e k-1 +e k-2 );

[0094] Among them, K p K is the proportionality coefficient. i K is the integration time constant. d e is the differential time constant. k e represents the temperature difference between the evaporation temperature of the air cooler detected in the kth sampling period and its corresponding target evaporation temperature. k-1 e represents the temperature difference between the evaporation temperature of the air cooler detected in the (k-1)th sampling period and its corresponding target evaporation temperature. k-2 This is the temperature difference between the evaporation temperature of the air cooler detected in the (k-2)th sampling period and its corresponding target evaporation temperature.

[0095] To improve the stability of unit startup, the preferred solution is to have each throttle valve operate at a set initial opening for a certain period of time when it is open, and then adjust the opening according to the temperature difference. The length of this "certain period of time" can be designed according to actual usage requirements, such as 1 minute.

[0096] In a preferred embodiment of the present invention, the temperature difference is calculated as follows for each air cooler:

[0097] Temperature difference ek = T in dehumidifier evaporative cooler 14 蒸发14 -T a1 T 蒸发14 The evaporation temperature of the dehumidifying air cooler 14 is T. a1 =T 除湿设定 -A1,T 除湿设定 The target temperature for the dehumidification room 19 is set for the user. To ensure that the dehumidifying air cooler does not frost, T 除湿设定 -A1>0, and the dehumidifying air cooler 14 uses high-pressure air delivery to ensure that the moisture on the items is dried. A1 is a set parameter, for example, the default set parameter A1 is 12℃.

[0098] The temperature difference of the first pre-cooling air cooler 15 is ek = T. 蒸发15 -T a2 T 蒸发15 The evaporation temperature of the first pre-cooling air cooler 15 is T, and the target evaporation temperature of the first pre-cooling air cooler 15 is T. a2 =T 预冷设定 -A2,T 预冷设定 The target temperature for the pre-cooling room 20 is set by the user. A2 is the set parameter, for example, the default set parameter A2 is 10℃.

[0099] The temperature difference of the second pre-cooling air cooler 16 is ek = T. 蒸发16 -Ta2 T 蒸发16 The evaporation temperature of the second pre-cooling air cooler 16 is T, and the target evaporation temperature of the second pre-cooling air cooler 16 is T. a2 =T 预冷设定 -A2,T 预冷设定 The target temperature for the pre-cooling room 20 is set by the user. A2 is the set parameter, for example, the default set parameter A2 is 10℃.

[0100] Temperature difference ek = T in quick-freezing air cooler 17 蒸发17 -T a3 T 蒸发17 The evaporation temperature of the quick-freezing air cooler 17 is T. The target evaporation temperature of the quick-freezing air cooler 17 is T. a3 =T 速冻设定 -A3,T 速冻设定 The target temperature for the quick-freezing room 21 is set by the user. A3 is the set parameter, for example, the default set parameter A3 is 8℃.

[0101] It should be understood that when the first pre-cooling air cooler 15 and the second pre-cooling air cooler 16 are operating simultaneously, the temperature difference ek between the air cooler evaporation temperature of the pre-cooling room 20 and the target evaporation temperature of the pre-cooling room 20 is T. 蒸发15 -T a2 +T 蒸发16 -T a2 The temperature difference ek in the precooling chamber 20 is the sum of the temperature differences between the evaporation temperature of each precooling air cooler in operation and the target evaporation temperature of the precooling chamber 20. The opening of the precooling throttle valve 4 is adjusted according to the temperature difference ek in the precooling chamber 20. When only the first precooling air cooler 15 is running, the temperature difference ek between the air cooler evaporation temperature and the target evaporation temperature of the precooling chamber 20 is T. 蒸发15 -T a2 The opening of the precooling throttle valve 4 is adjusted according to the temperature difference ek between the precooling chamber 20 and the target evaporation temperature of the precooling chamber 20. When only the second precooling air cooler 16 is running, the temperature difference ek between the air cooler evaporation temperature and the target evaporation temperature of the precooling chamber 20 is T. 蒸发16 -T a2 The opening of the precooling throttle valve 4 is adjusted according to the temperature difference ek between the precooling chamber 20 and the precooling chamber 20.

[0102] like Figure 5 As shown, after the pre-cooling air cooler is turned on, the air speed is adjusted according to the humidity inside the pre-cooling room 20 and the quick-freezing room 21. The air speed control of the pre-cooling air cooler only applies to normal pre-cooling air coolers. Specifically, the air speed control process includes:

[0103] After the pre-cooling air cooler is turned on, the humidity parameters of the pre-cooling room 20 and the quick-freezing room 21 are measured.

[0104] When ψ预冷 ≥C1 or ψ 速冻 When the temperature is ≥C2, it indicates that the air humidity in the pre-cooling room 20 or the quick-freezing room 21 is too high, according to ψ 预冷 The difference between C1 and C1 is used to adjust the speed of the pre-cooling air cooler so that the initial speed of the pre-cooling room matches the current demand. When the humidity is high, the speed is reduced to increase the dehumidification capacity, and when the humidity is low, the speed is increased to increase the cooling capacity.

[0105] When ψ 预冷 <C1 and ψ 速冻 When the temperature is <C2, it indicates that the air humidity in the pre-cooling room 20 and the quick-freezing room 21 is low, and the speed of the pre-cooling air cooler is set to the maximum speed V0 to achieve the maximum heat exchange efficiency.

[0106] Where, ψ 预冷 ψ represents the humidity inside the pre-cooling room. 速冻 C1 represents the target humidity inside the quick-freezing room, C2 represents the target humidity inside the pre-cooling room, and C3 represents the target humidity inside the quick-freezing room.

[0107] Specifically, in some embodiments of the present invention, the formula for calculating the rotational speed of the pre-cooling air cooler is as follows:

[0108] V=V0-K1×(ψ 预冷 -C1);

[0109] Where V is the rotational speed of the precooling air cooler, K1 is the setting coefficient, and V0 is the set maximum rotational speed of the precooling air cooler.

[0110] The design logic of this calculation formula is that the higher the humidity inside the pre-cooling room, the lower the speed of the pre-cooling air cooler and the greater the dehumidification capacity.

[0111] It should be noted that the terminology used above is for describing specific embodiments only and is not intended to limit the exemplary embodiments of the present invention. When the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. The order of execution of actions, steps, etc., in the apparatus and methods shown in the specification and drawings can be implemented in any order unless a specific order is expressly specified, and as long as the output of a previous process is not used in a subsequent process. Similar sequential terms used for ease of description do not imply that such an order must be followed.

[0112] Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0113] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. Control methods for a quick-freezing machine, which includes: The system includes multiple functional rooms, conveyor belts for transporting goods through each of the functional rooms, and refrigeration units; the multiple functional rooms include a pre-cooling room and a quick-freezing room, the pre-cooling room and the quick-freezing room are connected, the quick-freezing room is equipped with a quick-freezing air cooler, and the exhaust air from the quick-freezing room is sent back to the quick-freezing room through the pre-cooling room; the pre-cooling room is divided into at least two pre-cooling chambers, and each pre-cooling chamber is equipped with a pre-cooling air cooler that can operate independently. The control method is applied to the quick-freezing machine, characterized in that it includes: after turning on the pre-cooling air blower in the pre-cooling room, determining whether the pre-cooling air blower has reached the defrosting entry condition; If so, close the air inlet and outlet of the precooling chamber where the precooling air cooler is located, and defrost the precooling air cooler; If not, the pre-cooling air cooler continues to operate in cooling mode; The multiple functional rooms include a dehumidification room, a pre-cooling room, and a quick-freezing room arranged sequentially along the direction of goods transportation. The air coolers of each functional room are connected in parallel to the refrigerant circulation loop of the refrigeration unit, and a throttling valve is installed on the inlet side of each air cooler. The control method further includes: upon receiving a refrigeration start-up command, starting the refrigeration unit, and turning on the dehumidifying air cooler in the dehumidification room and the pre-cooling air cooler in the pre-cooling room; when T is detected... 预冷 ≤T0 and T 速冻 When T1 is less than or equal to 1, turn on the quick-freezing air cooler in the quick-freezing room; Among them, T 预冷 T represents the internal temperature of the pre-cooling room. 速冻 The temperature inside the quick-freezing room is T0, and T1 is a set temperature.

2. The control method according to claim 1, characterized in that, The air inlet of the precooling chamber is connected to the air outlet of the quick-freezing room, and the air outlet of the precooling chamber is connected to the air inlet of the quick-freezing room. When the precooling air cooler is in the defrosting state, both the air inlet and air outlet of the precooling chamber where the precooling air cooler is located are closed; When the quick-freezing machine is in refrigeration mode, at least one pre-cooling chamber's pre-cooling fan is in refrigeration operation, and both the air inlet and outlet of the pre-cooling chamber are open.

3. The control method according to claim 2, characterized in that, The air inlet of the precooling chamber is equipped with an inlet air valve that controls its on / off state; the air outlet of the precooling chamber is equipped with an outlet air valve that controls its on / off state.

4. The control method according to claim 3, characterized in that, The quick-freezing room is provided with an air supply duct and an air outlet duct. The air supply duct is connected to the air outlet of the pre-cooling chamber, and the air outlet duct is connected to the air inlet of the pre-cooling chamber. The conveyor belt has a pre-cooling conveying section that passes through the pre-cooling room. The pre-cooling conveying section is located between the air outlet duct and the air inlet of the pre-cooling chamber.

5. The control method according to any one of claims 1 to 4, characterized in that, The multiple functional rooms include a dehumidification room, a pre-cooling room, and a quick-freezing room arranged sequentially along the direction of goods transportation. The dehumidification room is separated from the pre-cooling room, and the dehumidification room is equipped with a dehumidifying air cooler connected to the refrigeration unit.

6. The control method according to claim 5, characterized in that, The air coolers for each function are connected in parallel to the refrigerant circulation loop of the refrigeration unit, and each air cooler is equipped with a throttling valve on its inlet side.

7. The control method according to claim 1, characterized in that, Also includes: The defrosting priority of each pre-cooled air cooler is preset. After it is determined that a pre-cooled air cooler has reached the defrosting entry condition, it is determined whether all pre-cooled air coolers have reached the defrosting entry condition. If so, the pre-cooling air conditioners are defrosted according to their defrosting priority, and at least one pre-cooling air conditioner is in cooling operation. If not, the pre-cooling air cooler that has not met the defrosting conditions will continue to operate in cooling mode.

8. The control method according to claim 1, characterized in that, Also includes: After the air cooler in any of the aforementioned functional rooms is turned on, the evaporation temperature of the air cooler in that functional room is detected and the temperature difference between the evaporation temperature and the corresponding target evaporation temperature is calculated. Adjust the opening of the throttle valve of the air cooler according to the temperature difference.

9. The control method according to claim 8, characterized in that, The change in the opening of the throttle valve for: ； in, This is the proportionality coefficient. The integral time constant is... The differential time constant is This represents the temperature difference between the evaporation temperature of the air cooler detected in the k-th sampling period and its corresponding target evaporation temperature. This represents the temperature difference between the evaporation temperature of the air cooler detected in the (k-1)th sampling period and its corresponding target evaporation temperature. It is the temperature difference between the evaporation temperature of the air cooler detected in the (k-2)th sampling period and its corresponding target evaporation temperature.

10. The control method according to claim 1, characterized in that, Also includes: After the pre-cooling air cooler is turned on, the humidity parameters of the pre-cooling room and the quick-freezing room are detected; When ψ 预冷 ≥C1 or ψ 速冻 When ≥C2, according to ψ 预冷 The difference between C1 and C2 is used to adjust the speed of the pre-cooling air cooler; When ψ 预冷 <C1 and ψ 速冻 When <C2, the pre-cooling air cooler operates at the set maximum speed V0; Where, ψ 预冷 ψ represents the humidity inside the pre-cooling room. 速冻 C1 is the target humidity of the quick-freezing room, C2 is the target humidity of the pre-cooling room, and C3 is the target humidity of the quick-freezing room.

11. The control method according to claim 10, characterized in that, According to ψ 预冷 Adjusting the speed of the pre-cooling air cooler by the difference between C1 and C1 includes: ； Where V is the rotational speed of the pre-cooling air cooler. To set coefficients, This is the set maximum speed of the pre-cooling air cooler.

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