Oxygen reduction device, refrigerator and control method

Abstract

The invention discloses an oxygen reduction device, a refrigerator and a control method, the oxygen reduction device comprises: a housing, the interior of which is divided by a first partition plate into a first chamber and a second chamber which are independent from each other; an air inlet cavity communicated with the front ports of the two cavities is formed in the shell, and an air supply assembly is arranged in the air inlet cavity; air door assemblies used for controlling connection and disconnection of the corresponding cavities and the air inlet cavity are arranged at the front ports respectively; the rear ports of the two chambers are provided with collecting cavities communicating with the air exhaust assembly. A plurality of groups of first air outlet holes are formed in the inner walls of the two cavities in the thickness direction of the shell; a plurality of first hollow fiber membrane bundles and a plurality of second hollow fiber membrane bundles which extend along the axial direction are respectively arranged in the two cavities; the nitrogen-oxygen separation coefficient and the water absorption rate of the second hollow fiber membrane bundle are greater than those of the first hollow fiber membrane bundle; the first ends, facing the front ports, of the two hollow fiber membrane bundles are both of a closed structure, and the second ends are both in an open state and communicated with the collection cavity. Therefore, different requirements on nitrogen-oxygen separation efficiency and moisture resistance in different oxygen reduction stages are met, and the service life of the membrane bundle is prolonged.

Description

Technical Field

[0001] This invention relates to the field of gas separation technology, and in particular to oxygen reduction devices, refrigerators, and control methods. Background Technology

[0002] Currently, the core technologies of refrigerators in preserving fruits and vegetables mainly rely on low-temperature environment control and humidity regulation to extend shelf life by inhibiting microbial growth and the metabolic rate of fruits and vegetables. However, fruits and vegetables continue to undergo aerobic respiration during refrigeration, leading to the consumption of nutrients, tissue aging, and a decline in taste. To address this issue, some high-end refrigerators have begun to introduce oxygen-reducing preservation technology in recent years, which further inhibits the respiration of fruits and vegetables by reducing the oxygen concentration in the storage environment.

[0003] Current oxygen-reducing preservation technologies mainly employ hollow fiber membranes to separate nitrogen and oxygen. This method selectively permeates oxygen while enriching nitrogen, thereby reducing the proportion of oxygen in the environment. However, in practical applications, this technology has been found to have the following shortcomings:

[0004] (1) Limited material selection: It is difficult for a single hollow fiber membrane material to achieve both high nitrogen and oxygen separation coefficient and good moisture resistance. For example, polyimide material has a high separation coefficient (6-8), but its water absorption rate is high, and it is easy to cause performance degradation or even failure when exposed to high humidity for a long time; while polysulfone material has good moisture resistance, but its separation coefficient is low (4-6), resulting in low oxygen reduction efficiency. (2) Poor dynamic response capability: Existing systems usually operate with fixed parameters and cannot be dynamically adjusted according to changes in the oxygen reduction process. This leads to low efficiency in the early stage of oxygen reduction, and over-adjustment is easy to occur when the oxygen concentration is reduced and close to the target concentration, resulting in energy waste or oxygen concentration fluctuations. (3) Short material life: Due to the high humidity in the fruit and vegetable drawer, hollow fiber membrane, especially polyimide material, may still undergo structural aging due to moisture absorption when not in operation, affecting its service life and separation efficiency. (4) Lack of intelligent control strategy: Existing oxygen reduction systems lack the ability to monitor and predict the oxygen reduction process in real time, and cannot make intelligent decisions based on the current oxygen concentration change trend, resulting in a lag in control strategy and affecting the preservation effect. Summary of the Invention

[0005] This invention provides an oxygen reduction device, a refrigerator, and a control method to address the problem that existing oxygen reduction devices using hollow fiber membranes cannot meet the different requirements for nitrogen and oxygen separation efficiency and moisture resistance at different stages, resulting in low oxygen reduction efficiency and short material lifespan of the hollow fiber membranes.

[0006] The technical solution adopted in this invention is to design an oxygen reduction device, comprising:

[0007] The housing is divided into a first chamber and a second chamber by a first partition. An air inlet chamber is provided at the first end of the housing along its axial direction. The air inlet chamber is connected to the front ports of the first chamber and the second chamber. An air supply assembly is provided in the air inlet chamber. The front ports of the first chamber and the second chamber are respectively provided with damper assemblies for controlling the connection and disconnection between the corresponding chamber and the air inlet chamber.

[0008] Both the first chamber and the second chamber have a collection chamber at their rear ports, and each collection chamber is connected to the air extraction assembly; the first chamber and the second chamber have multiple sets of first air outlets on their inner walls along the thickness direction of the housing.

[0009] The first chamber is provided with a plurality of first hollow fiber membrane bundles extending along the axial direction, and the second chamber is provided with a plurality of second hollow fiber membrane bundles extending along the axial direction; the nitrogen-oxygen separation coefficient and water absorption rate of the second hollow fiber membrane bundles are both greater than those of the first hollow fiber membrane bundles.

[0010] The first ends of both the first hollow fiber membrane bundle and the second hollow fiber membrane bundle facing the front port are closed structures, and the second ends of both the first hollow fiber membrane bundle and the second hollow fiber membrane bundle are open and communicate with the collection cavity.

[0011] Furthermore, the damper assembly includes a first damper and a second damper;

[0012] The first chamber is provided with a first damper at its front port, which is used to control the connection between the first chamber and the air inlet chamber.

[0013] The front port of the second chamber is provided with a second damper, which is used to control the connection and disconnection between the second chamber and the air inlet chamber;

[0014] Furthermore, the first damper and the second damper will not be activated simultaneously.

[0015] Furthermore, a moisture-absorbing component is provided in the second chamber, which is used to perform moisture-absorbing and drying treatment on the interior of the second chamber.

[0016] Furthermore, the moisture-absorbing component is composed of a solid porous moisture-absorbing material, which includes at least one of metal-organic framework materials, covalent organic framework materials, and porous organic polymers.

[0017] Furthermore, the air extraction assembly includes a vacuum pump, a first air extraction pipe, a second air extraction pipe, and a solenoid valve;

[0018] The first chamber is connected to the vacuum pump via the first suction pipe;

[0019] The second chamber is connected to the first suction pipe through the second suction pipe, and a solenoid valve is provided at the connection between the first suction pipe and the second suction pipe. The solenoid valve is used to selectively open the first suction pipe and close the second suction pipe, or close the first suction pipe and open the second suction pipe.

[0020] Furthermore, a second partition is provided at the rear port of the collection cavity corresponding to the first chamber and the second chamber, and the edge of the second partition is sealed to the inner wall of the corresponding chamber.

[0021] The second ends of all the first hollow fiber membrane bundles and all the second hollow fiber membrane bundles are in contact with the second partition, and the contact position of the second partition is provided with a second air outlet.

[0022] Furthermore, the material used to manufacture the first hollow fiber membrane bundle includes any one of polysulfone, polyethersulfone, and cellulose acetate.

[0023] Furthermore, the material used to manufacture the second hollow fiber membrane bundle includes any one of polyimide, polyamide, and polytetrafluoroethylene.

[0024] The present invention also proposes a refrigerator comprising at least one compartment, wherein the compartment integrates an oxygen reduction device as described above.

[0025] Furthermore, an oxygen concentration detection device is also installed in the room, which is used to detect the oxygen concentration in the corresponding room in real time.

[0026] The present invention also proposes a control method for a refrigerator as described above, the control method comprising:

[0027] Place the fruits and vegetables into the compartment of the refrigerator and activate the air supply and exhaust components;

[0028] Real-time collection of oxygen concentration parameters within the chamber;

[0029] The collected oxygen concentration parameters are curve-fitted to generate an oxygen concentration change trend curve.

[0030] Analyze the slope k of the oxygen concentration change trend curve, and divide the oxygen reduction stage according to the slope k;

[0031] Depending on the different deoxygenation stages, the opening and closing of the damper assembly is controlled so that the airflow delivered by the air supply assembly enters the first chamber or the second chamber.

[0032] Further, based on the slope, the oxygen reduction stages are divided, and the control method includes:

[0033] When the absolute value of the slope During the deoxygenation phase, which is in the rapid separation zone, the first air damper is activated and the second air damper is closed.

[0034] When the absolute value of the slope During the oxygen reduction phase, which is in a transition zone, the first air damper is activated and the second air damper is closed.

[0035] When the absolute value of the slope During the deoxygenation phase, which is in the slow separation zone, the first air damper is closed and the second air damper is activated.

[0036] Furthermore, the control method includes:

[0037] When the oxygen reduction stage is in the rapid separation zone, the rotation speed of the air supply component is the initial rotation speed n, and the working power of the air extraction component is the initial preset power P.

[0038] When the oxygen reduction stage is in the transition zone, the rotation speed of the air supply component is 2n, and the working power of the air extraction component is 2P.

[0039] When the oxygen reduction stage is in the slow separation zone, the rotation speed of the air supply component is 2n, and the working power of the air extraction component is P.

[0040] Compared with the prior art, the present invention has at least the following beneficial effects:

[0041] This invention controls the entry of raw gas into the first or second chamber through a damper assembly, and utilizes a first and second hollow fiber membrane bundle with complementary properties to meet the different requirements of nitrogen-oxygen separation efficiency and moisture resistance at different deoxygenation stages, thus balancing high separation efficiency and moisture resistance and extending the material service life of the hollow fiber membrane bundle. Attached Figure Description

[0042] The present invention will now be described in detail with reference to the embodiments and accompanying drawings, wherein:

[0043] Figure 1 This is a schematic diagram of the first internal structure of the oxygen reduction device proposed in this invention.

[0044] Figure 2 for Figure 1 An enlarged schematic diagram of reference numeral A in the attached figure;

[0045] Figure 3 This is a schematic diagram of the second internal structure of the oxygen reduction device proposed in this invention;

[0046] Figure 4 for Figure 3 An enlarged view of reference numeral B in the attached diagram;

[0047] Figure 5This is a schematic diagram of the internal structure of the first type of air extraction component proposed in this invention;

[0048] Figure 6 This is a schematic diagram of the internal structure of the second type of air extraction component proposed in this invention;

[0049] Figure 7 This is a schematic diagram of the internal structure of the refrigerator compartments proposed in this invention;

[0050] Figure 8 This is the first flowchart of the refrigerator control method proposed in this invention;

[0051] Figure 9 This is a schematic diagram of the oxygen concentration change trend curve proposed in this invention;

[0052] Figure 10 This is the second flowchart of the refrigerator control method proposed in this invention.

[0053] Attached Figure Description: 10. Shell;

[0054] 101. First partition; 102. First chamber; 103. Second chamber; 104. Air inlet chamber; 105. Collecting chamber; 106. First air outlet; 107. Second partition; 108. Second air outlet; 109. Fixing component; 110. Air outlet;

[0055] 20. Air supply components;

[0056] 30. Damper assembly;

[0057] 301. First air damper; 302. Second air damper;

[0058] 40. Air extraction assembly;

[0059] 401. Vacuum pump; 402. First extraction pipe; 403. Second extraction pipe; 404. Solenoid valve;

[0060] 50. First hollow fiber membrane bundle;

[0061] 60. Second hollow fiber membrane bundle;

[0062] 70. Moisture-absorbing components;

[0063] 80. Room;

[0064] 90. Oxygen concentration detection device. Detailed Implementation

[0065] 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.

[0066] Currently, the core technologies of refrigerators in preserving fruits and vegetables mainly rely on low-temperature environment control and humidity regulation to extend shelf life by inhibiting microbial growth and the metabolic rate of fruits and vegetables. However, fruits and vegetables continue to undergo aerobic respiration during refrigeration, leading to the consumption of nutrients, tissue aging, and a decline in taste. To address this issue, some high-end refrigerators have begun to introduce oxygen-reducing preservation technology in recent years, which further inhibits the respiration of fruits and vegetables by reducing the oxygen concentration in the storage environment.

[0067] Current oxygen-reducing preservation technologies mainly employ hollow fiber membranes to separate nitrogen and oxygen. This method selectively permeates oxygen while enriching nitrogen, thereby reducing the proportion of oxygen in the environment. However, in practical applications, this technology has been found to have the following shortcomings:

[0068] (1) Limited material selection: It is difficult for a single hollow fiber membrane material to achieve both high nitrogen and oxygen separation coefficient and good moisture resistance. For example, polyimide material has a high separation coefficient (6-8), but its water absorption rate is high, and it is easy to cause performance degradation or even failure when exposed to high humidity for a long time; while polysulfone material has good moisture resistance, but its separation coefficient is low (4-6), resulting in low oxygen reduction efficiency. (2) Poor dynamic response capability: Existing systems usually operate with fixed parameters and cannot be dynamically adjusted according to changes in the oxygen reduction process. This leads to low efficiency in the early stage of oxygen reduction, and over-adjustment is easy to occur when the oxygen concentration is reduced and close to the target concentration, resulting in energy waste or oxygen concentration fluctuations. (3) Short material life: Due to the high humidity in the fruit and vegetable drawer, hollow fiber membrane, especially polyimide material, may still undergo structural aging due to moisture absorption when not in operation, affecting its service life and separation efficiency. (4) Lack of intelligent control strategy: Existing oxygen reduction systems lack the ability to monitor and predict the oxygen reduction process in real time, and cannot make intelligent decisions based on the current oxygen concentration change trend, resulting in a lag in control strategy and affecting the preservation effect.

[0069] Therefore, in some embodiments, such as Figure 1 As shown, this invention proposes an oxygen reduction device that can meet the different requirements for nitrogen and oxygen separation efficiency and moisture resistance at different stages, improve oxygen reduction efficiency, and extend the material service life of hollow fiber membranes, comprising:

[0070] The housing 10 is internally divided by a first partition 101 to form an independent first chamber 102 and a second chamber 103. An air inlet chamber 104 is provided at the first end along its axial direction inside the housing 10. The air inlet chamber 104 communicates with the front ports of the first chamber 102 and the second chamber 103. An air supply assembly 20 is provided inside the air inlet chamber 104. The front ports of the first chamber 102 and the second chamber 103 are respectively provided with damper assemblies 30 for controlling the opening and closing of the corresponding chamber with the air inlet chamber 104.

[0071] The rear ports of the first chamber 102 and the second chamber 103 are each provided with a sealed collection chamber 105, and each collection chamber 105 is connected to the air extraction assembly 40; the first chamber 102 and the second chamber 103 are provided with multiple sets of first air outlets 106 along the inner wall of the shell 10 in the thickness direction.

[0072] The first chamber 102 is provided with a plurality of first hollow fiber membrane bundles 50 extending along the axial direction, and the second chamber 103 is provided with a plurality of second hollow fiber membrane bundles 60 extending along the axial direction; the nitrogen-oxygen separation coefficient and water absorption rate of the second hollow fiber membrane bundles 60 are both greater than those of the first hollow fiber membrane bundles 50.

[0073] The first ends of the first hollow fiber membrane bundle 50 and the second hollow fiber membrane bundle 60 facing the front port are both closed structures, and the second ends of the first hollow fiber membrane bundle 50 and the second hollow fiber membrane bundle 60 are both open and communicate with the collection cavity 105.

[0074] It should be noted that the oxygen reduction device proposed in this embodiment is applied inside the refrigerator compartment 80, and the oxygen reduction device also includes a controller. Furthermore, the front and rear ports proposed in this embodiment are preferably oriented along the length, axis, or X-axis of the housing 10, the thickness of the housing 10 is preferably along the Z-axis, and the width of the housing 10 is preferably along the Y-axis. The air supply assembly 20 proposed in this embodiment is preferably a fan or blower, and the housing 10 is provided with an air outlet 110 corresponding to the air supply assembly 20.

[0075] The first hollow fiber membrane bundle 50 and the second hollow fiber membrane bundle 60 are both composed of multiple hollow fiber membrane filaments. The permeate gas inside the hollow fiber membrane filaments can only flow into the collecting cavity 105 through the second end, and then be extracted to the outside of the refrigerator by the extraction assembly 40. The multiple first hollow fiber membrane bundles 50 are spaced apart along the width direction of the shell 10 in the first chamber 102, and the multiple second hollow fiber membrane bundles 60 are spaced apart along the width direction of the shell 10 in the second chamber 103.

[0076] Thus, when the oxygen reduction device is activated, the controller activates the air supply assembly 20 and the air extraction assembly 40. At this time, the controller controls the damper assembly 30 to connect the first chamber 102 with the air inlet chamber 104. That is, the air supply assembly 20 sends the air (equivalent to the raw material gas, the same throughout) from the chamber 80 into the first chamber 102. At this time, the activation of the air extraction assembly 40 ensures that a pressure difference is formed inside and outside the first hollow fiber membrane bundle 50. When the raw material gas passes through the first hollow fiber membrane bundle 50, the fast-permeating components (such as oxygen) in the raw material gas preferentially dissolve outside the first hollow fiber membrane bundle 50 and permeate and diffuse through the membrane material. The low-pressure side (i.e., the inner cavity of the first hollow fiber membrane bundle 50) of the hollow fiber membrane bundle 50 is desorbed. The desorbed oxygen is collected in the inner cavity and flows to the collection cavity 105, thereby realizing the separation and purification of the raw material gas (i.e., oxygen-rich gas is formed inside the membrane of the first hollow fiber membrane bundle 50, and nitrogen-rich gas is formed outside the membrane). Then, the oxygen-rich gas in the collection cavity 105 is extracted by the extraction component 40 to the outside of the compartment 80 or the refrigerator. The separated and purified raw material gas (equivalent to nitrogen-rich gas) is discharged back into the compartment 80 through the first vent 106 of the first compartment 102, thereby ensuring that the oxygen concentration in the corresponding compartment 80 gradually decreases.

[0077] When the oxygen concentration in chamber 80 drops to a predetermined value, a hollow fiber membrane bundle with a higher nitrogen-oxygen separation coefficient is required. Therefore, the controller will control the damper assembly 30 to connect the second chamber 103 with the air inlet chamber 104. That is, the air supply assembly 20 sends the raw material gas from chamber 80 into the second chamber 103. When the raw material gas passes through the second hollow fiber membrane bundle 60, the fast-permeable components (such as oxygen) in the raw material gas preferentially dissolve outside the membrane of the second hollow fiber membrane bundle 60 and permeate and diffuse through the membrane material. They are desorbed on the low-pressure side (i.e., the inner cavity of the second hollow fiber membrane bundle 60). Oxygen is collected in the inner cavity and flows to the collection chamber 105, thereby achieving the separation and purification of the raw material gas (i.e., oxygen-rich gas is formed inside the membrane of the second hollow fiber membrane bundle 60, and nitrogen-rich gas is formed outside the membrane). Then, the oxygen-rich gas in the collection chamber 105 is extracted by the extraction component 40 to the outside of the chamber 80 or the refrigerator. The separated and purified raw material gas (equivalent to nitrogen-rich gas) is discharged back into the chamber 80 through the first vent 106 of the second chamber 103, thereby ensuring that the oxygen concentration in the corresponding chamber 80 eventually drops to the required oxygen concentration. Finally, the controller shuts off the air supply component 20 and the extraction component 40, and the oxygen reduction device stops operating.

[0078] Therefore, the present invention controls the raw material gas to enter the first chamber 102 or the second chamber 103 through the damper assembly 30, and utilizes the complementary characteristics of the first hollow fiber membrane bundle 50 and the second hollow fiber membrane bundle 60 (double hollow fiber membrane structure) to meet the different requirements of nitrogen and oxygen separation efficiency and moisture resistance at different oxygen reduction stages, taking into account both high separation efficiency and moisture resistance, and extending the material service life of the hollow fiber membrane bundle.

[0079] The housing 10 is provided with a fixing member 109 at the first end of all the first hollow fiber membrane bundles 50 and the second hollow fiber membrane bundles 60 to ensure the stability of the first hollow fiber membrane bundles 50 and the second hollow fiber membrane bundles 60 during transportation.

[0080] In some embodiments, to precisely control the communication between the intake chamber 104 and the first chamber 102 or the second chamber 103, such as... Figure 1 As shown, the damper assembly 30 includes a first damper 301 and a second damper 302;

[0081] The front port of the first chamber 102 is provided with a first damper 301, which is used to control the connection and disconnection between the first chamber 102 and the air inlet chamber 104.

[0082] The front port of the second chamber 103 is provided with a second damper 302, which is used to control the connection and disconnection between the second chamber 103 and the air inlet chamber 104;

[0083] Furthermore, the first damper 301 and the second damper 302 will not be activated simultaneously.

[0084] Both the first damper 301 and the second damper 302 consist of a valve plate and a motor. The motor is electrically connected to the controller, which drives the valve plate to rotate via the motor to close the corresponding chamber and prevent airflow from entering. Furthermore, the first damper 301 and the second damper 302 do not activate simultaneously; that is, if the first damper 301 activates at the same time, the second damper 302 will close, effectively meaning that the air intake chamber 104 communicates only with the first chamber 102 (e.g., ...). Figure 3 As shown); similarly, when the first damper 301 closes, the second damper 302 opens, which means that the intake chamber 104 is only connected to the second chamber 103 (as shown). Figure 1 (As shown).

[0085] In some embodiments, such as Figure 2 As shown, a moisture-absorbing component 70 is provided in the second chamber 103, and the moisture-absorbing component 70 is used to perform moisture-absorbing and drying treatment on the inside of the second chamber 103.

[0086] It should be noted that the moisture-absorbing component 70 is disposed on the side wall of the first partition 101 facing the second chamber 103.

[0087] Thus, when the controller activates the first damper 301 and closes the second damper 302, the moisture absorption component 70 is in a normal pressure environment and performs moisture absorption and drying during the non-working period of the second hollow fiber membrane bundle 60, avoiding the second hollow fiber membrane bundle 60 being in a high humidity environment for a long time and effectively extending the service life of the second hollow fiber membrane bundle 60. When the controller closes the first damper 301 and activates the second damper 302, the second hollow fiber membrane bundle 60 is in operation, the airflow velocity on the surface of the moisture absorption component 70 increases, and the pressure decreases (equivalent to the moisture absorption component 70 being in a depressurized environment). At this time, the moisture absorbed by the moisture absorption component 70 will be re-extracted, and then the extracted moisture will be discharged back into the chamber 80 through the first vent 106 along with the nitrogen-rich gas in the second chamber 103, increasing the humidity in the chamber 80 and delaying the water loss of the fruits and vegetables in the chamber 80.

[0088] Of course, in other embodiments (not shown in the figures), the oxygen reduction device also includes:

[0089] A moisture-absorbing component 70 is disposed within the second chamber 103;

[0090] An opening and closing assembly is connected to the moisture-absorbing assembly 70; the opening and closing assembly is used to open or close the moisture-absorbing assembly 70 relative to the second chamber 103.

[0091] When the opening and closing assembly is in the open state, the moisture-absorbing assembly 70 is exposed to the second chamber 103 for moisture absorption and drying; when the opening and closing assembly is in the closed state, the moisture-absorbing assembly 70 is isolated from the second chamber 103.

[0092] Thus, when the controller activates the first damper 301 and closes the second damper 302, the controller controls the opening and closing components to be in the open state so that the moisture absorption component 70 can perform moisture absorption and drying treatment during the non-working period of the second hollow fiber membrane bundle 60, thereby preventing the second hollow fiber membrane bundle 60 from being in a high humidity environment for a long time and effectively extending the service life of the second hollow fiber membrane bundle 60.

[0093] When the controller closes the first damper 301 and activates the second damper 302, the second hollow fiber membrane bundle 60 is in operation, and there are two scenarios:

[0094] Firstly, there is no need to increase humidity in chamber 80. At this time, the controller controls the opening and closing components to be in the closed state, and the moisture absorption component 70 is isolated from the second chamber 103. The moisture absorption component 70 neither absorbs moisture and dries, nor decomposes moisture.

[0095] Secondly, when the humidity in the chamber 80 needs to be increased, the controller controls the opening and closing components to be in the open state. At this time, the airflow velocity on the surface of the moisture absorption component 70 increases and the pressure decreases. The moisture absorbed by the moisture absorption component 70 will be re-extracted, and then the extracted moisture will be discharged back into the chamber 80 through the first air outlet 106 along with the nitrogen-rich gas in the second chamber 103, thereby increasing the humidity in the chamber 80.

[0096] Specifically, the moisture-absorbing component 70 is composed of a solid porous moisture-absorbing material, which includes at least one of metal-organic framework materials, covalent organic framework materials, and porous organic polymers.

[0097] Thus, the moisture-absorbing component 70 is composed of a solid porous moisture-absorbing material, rather than a liquid (such as LiBr, LiCl, CaCl2 solution), powder, or easily detachable particle desiccant. This is because liquid, powder, or easily detachable particle desiccant may generate droplets, powder, or tiny particles entrained in the airflow. Once these particles enter the second hollow fiber membrane bundle 60, they will block the membrane pores of the second hollow fiber membrane bundle 60, causing a sharp drop in the membrane permeation flux of the second hollow fiber membrane bundle 60, and even causing irreversible pollution.

[0098] In some embodiments, such as Figure 1 As shown, the air extraction assembly 40 includes a vacuum pump 401, a first air extraction pipe 402, a second air extraction pipe 403, and a solenoid valve 404.

[0099] The first chamber 102 is connected to the vacuum pump 401 via the first suction pipe 402;

[0100] The second chamber 103 is connected to the first suction pipe 402 through the second suction pipe 403, and a solenoid valve 404 is provided at the connection between the first suction pipe 402 and the second suction pipe 403. The solenoid valve 404 is used to selectively open the first suction pipe 402 and close the second suction pipe 403, or to close the first suction pipe 402 and open the second suction pipe 403.

[0101] Thus, when the first damper 301 is activated and the second damper 302 is closed, the controller activates the solenoid valve 404 to open the first extraction pipe 402 and close the second extraction pipe 403 (e.g., Figure 5 As shown), so that the vacuum pump 401 can ensure that a pressure difference is formed inside and outside the first hollow fiber membrane bundle 50, and extract the oxygen-enriched gas from the collection chamber 105 corresponding to the first chamber 102 from the refrigerator; similarly, when the first damper 301 is closed and the second damper 302 is activated, the controller activates the solenoid valve 404, so that the solenoid valve 404 closes the first extraction pipe 402 and opens the second extraction pipe 403 (as shown). Figure 6As shown), so that the vacuum pump 401 can ensure that a pressure difference is formed inside and outside the second hollow fiber membrane bundle 60, and extract the oxygen-enriched gas from the collection chamber 105 corresponding to the second chamber 103 from the refrigerator.

[0102] In some embodiments, to ensure that the oxygen-enriched gas separated from the first hollow fiber membrane bundle 50 and the second hollow fiber membrane bundle 60 can be stably delivered to the corresponding collection cavity 105, such as... Figure 1 and Figure 4 As shown, the collection cavity 105 is provided with a second partition 107 at the rear port corresponding to the first chamber 102 and the second chamber 103, and the edge of the second partition 107 is sealed to the inner wall of the corresponding chamber.

[0103] The second ends of all the first hollow fiber membrane bundles 50 and all the second hollow fiber membrane bundles 60 are in contact with the second partition 107, and the contact positions of the second partition 107 are provided with second air outlets 108.

[0104] It should be noted that each hollow fiber membrane bundle has multiple second air outlets 108 at the contact position with the second partition 107, and the multiple second air outlets 108 in the same contact position are arranged at intervals along a circumferential direction to form a ring array, and the shape of the ring array corresponds to the shape of the second end of the corresponding hollow fiber membrane bundle.

[0105] The first hollow fiber membrane bundle 50 is made of any one of polysulfone, polyethersulfone, and cellulose acetate.

[0106] The material used to make the second hollow fiber membrane bundle 60 includes any one of polyimide, polyamide, and polytetrafluoroethylene.

[0107] Understandably, the optimal material for the first hollow fiber membrane bundle 50 is polysulfone, which is moisture-resistant (with low water absorption) and has a nitrogen-oxygen separation coefficient of 4-6; the optimal material for the second hollow fiber membrane bundle 60 is polyimide, which has a higher nitrogen-oxygen separation coefficient (6-8), but is not moisture-resistant (with high water absorption).

[0108] By combining the first hollow fiber membrane bundle 50 and the second hollow fiber membrane bundle 60, the different requirements of nitrogen and oxygen separation efficiency and moisture resistance of the membrane material at different oxygen reduction stages can be met, achieving optimal matching of material performance, as detailed below:

[0109] When fruits and vegetables are placed in chamber 80, the oxygen concentration in chamber 80 is relatively high. At this time, the oxygen is first reduced by the first hollow fiber membrane bundle 50. After the oxygen concentration in chamber 80 is reduced to the specified concentration, the process switches to the second hollow fiber membrane bundle 60, which has a higher nitrogen-oxygen separation coefficient, to further reduce the oxygen concentration in chamber 80 and achieve the final oxygen reduction requirement.

[0110] In some embodiments, the present invention also provides a refrigerator comprising at least one compartment 80, wherein the compartment 80 integrates an oxygen reduction device as described above.

[0111] It should be noted that the compartment 80 proposed in this embodiment has a drawer structure.

[0112] Thus, when fruits and vegetables are placed in chamber 80 and the oxygen-reducing device is activated, the controller activates the air supply assembly 20 and the air extraction assembly 40. At this time, the controller controls the damper assembly 30 to connect the first chamber 102 with the air inlet chamber 104. That is, the air supply assembly 20 sends the raw material gas from chamber 80 into the first chamber 102. The activation of the air extraction assembly 40 ensures that a pressure difference is formed across the first hollow fiber membrane bundle 50. When the raw material gas passes through the first hollow fiber membrane bundle 50, the fast-permeating components in the raw material gas preferentially penetrate the first hollow fiber membrane. The oxygen in the first hollow fiber membrane bundle 50 dissolves outside the membrane and diffuses through the membrane material, desorbing in the inner cavity of the first hollow fiber membrane bundle 50. The desorbed oxygen gathers in the inner cavity and flows to the collection chamber 105, thereby achieving the separation and purification of the raw material gas. Then, the oxygen-rich gas in the collection chamber 105 is extracted by the extraction component 40 to the outside of the chamber 80 or the refrigerator. The separated and purified raw material gas (equivalent to nitrogen-rich gas) is discharged back into the chamber 80 through the first vent 106 of the first chamber 102, thereby ensuring that the oxygen concentration in the corresponding chamber 80 gradually decreases.

[0113] When the oxygen concentration in chamber 80 drops to a predetermined value, a hollow fiber membrane bundle with a higher nitrogen-oxygen separation coefficient is required. Therefore, the controller will control the damper assembly 30 to connect the second chamber 103 with the air inlet chamber 104. That is, the air supply assembly 20 sends the raw material gas from chamber 80 into the second chamber 103. When the raw material gas passes through the second hollow fiber membrane bundle 60, the oxygen in the raw material gas preferentially dissolves outside the membrane of the second hollow fiber membrane bundle 60 and permeates and diffuses through the membrane material, desorbing inside the second hollow fiber membrane bundle 60. The desorbed oxygen is collected in the inner cavity and flows to the collection chamber 105, thereby achieving the separation and purification of the raw material gas. Then, the oxygen-enriched gas in the collection chamber 105 is extracted by the extraction component 40 to the outside of the chamber 80 or the refrigerator. The separated and purified raw material gas (equivalent to nitrogen-enriched gas) is discharged back into the chamber 80 through the first air outlet 106 of the second chamber 103, thereby ensuring that the oxygen concentration in the corresponding chamber 80 eventually drops to the required oxygen concentration. Finally, the controller shuts off the air supply component 20 and the extraction component 40, and the oxygen reduction device stops operating.

[0114] Therefore, the present invention controls the raw material gas to enter the first chamber 102 or the second chamber 103 through the damper assembly 30, and utilizes the complementary characteristics of the first hollow fiber membrane bundle 50 and the second hollow fiber membrane bundle 60 (double hollow fiber membrane structure) to meet the different requirements of nitrogen and oxygen separation efficiency and moisture resistance at different oxygen reduction stages, taking into account both high separation efficiency and moisture resistance, and improving oxygen reduction efficiency.

[0115] In some embodiments, such as Figure 7 As shown, an oxygen concentration detection device 90 is also installed in the chamber 80, which is used to detect the oxygen concentration in the corresponding chamber 80 in real time.

[0116] In this way, the controller can monitor changes in oxygen concentration in real time and generate an oxygen concentration change trend curve. Based on the slope k of the curve, the oxygen reduction process is divided into three stages (rapid separation zone, transition zone, and slow separation zone). The controller can dynamically adjust the selection of hollow fiber membrane bundles according to the stage changes and coordinate the control of the operating parameters of the air supply component 20 and the air extraction component 40 to achieve efficient oxygen reduction in different stages, improve the system response speed and control accuracy, and also improve the overall system energy efficiency and stability.

[0117] Specifically, the oxygen reduction process for the refrigerator proposed in this invention is as follows:

[0118] Start-up phase: The user places fruits and vegetables into compartment 80 and closes the door. The controller starts the vacuum pump 401 and the air supply component 20, and oxygen reduction begins inside compartment 80. The preset oxygen reduction time is t (2h≤t≤4h).

[0119] Rapid separation stage: The controller activates the first damper 301 and closes the second damper 302. The vacuum pump 401 operates at its initial preset power, and the air supply assembly 20 operates at its initial speed, drawing the raw material gas from the chamber 80 into the housing 10. The raw material gas passes over the surface of the first hollow fiber membrane bundle 50, where oxygen dissolves, diffuses, and decomposes within the membrane under the pressure difference between the inside and outside. During this process, oxygen-rich gas forms inside the membrane, and nitrogen-rich gas forms outside. The oxygen-rich gas is drawn out of the refrigerator by the vacuum pump 401 and re-enters the chamber 80, causing the oxygen concentration within the chamber 80 to gradually decrease.

[0120] When the second damper 302 is closed, the moisture absorption component 70 will continue to dry the second hollow fiber membrane bundle 60 to ensure that the second hollow fiber membrane bundle 60 is not in a high humidity environment for a long time, so as to extend the service life of the second hollow fiber membrane bundle 60.

[0121] Transition Phase: The rate of oxygen concentration decrease slows down. The controller continues to use the first hollow fiber membrane bundle 50, but increases the rotational speed of the air supply assembly 20 and the power of the vacuum pump 401 to accelerate separation. Increasing the power of the vacuum pump 401 can increase the oxygen pressure difference across the membrane, accelerating membrane dissolution and permeation. Increasing the rotational speed of the air supply assembly 20 can accelerate the replacement of the feed gas and also increase the decomposition rate.

[0122] Slow separation stage: When the oxygen concentration approaches the target value (the final oxygen concentration required in compartment 80), the controller closes the first damper 301 and activates the second damper 302 to switch to and use the second hollow fiber membrane bundle 60, continuing to reduce oxygen with a high nitrogen-oxygen separation coefficient. Simultaneously, the power of the vacuum pump 401 is reduced to the initial preset power. With a high nitrogen-oxygen separation coefficient, maintaining a certain pressure difference across the membrane is sufficient to achieve nitrogen-oxygen separation, thus reducing energy consumption. At the same time, the rotation speed of the air supply assembly 20 remains constant. During this stage, the nitrogen concentration is high, and concentration polarization is easily generated outside the membrane. Increasing the rotation speed of the air supply assembly 20 can accelerate the gas flow outside the membrane, prevent nitrogen accumulation, and accelerate the separation rate.

[0123] Membrane module dormancy phase: When the preset oxygen de-oxidation time t is reached, the controller will stop the air supply assembly 20 and vacuum pump 401, and the chamber 80 will stop oxygen de-oxidation. The moisture absorption assembly 70 will dry the second hollow fiber membrane bundle 60.

[0124] Periodic monitoring and adjustment: The controller is periodically woken up (e.g., every 24 hours) to restart the oxygen reduction process.

[0125] In some embodiments, such as Figure 8 and Figure 9 As shown, the present invention also proposes a control method for a refrigerator as described above, the control method comprising:

[0126] Place the fruits and vegetables into the refrigerator compartment 80 and start the air supply assembly 20 and the air extraction assembly 40;

[0127] Real-time collection of oxygen concentration parameters within the chamber 80;

[0128] The collected oxygen concentration parameters are curve-fitted to generate an oxygen concentration change trend curve.

[0129] Analyze the slope k of the oxygen concentration change trend curve, and divide the oxygen reduction stage according to the slope k;

[0130] Depending on the different oxygen reduction stages, the opening and closing of the damper assembly 30 is controlled so that the airflow delivered by the air supply assembly 20 enters the first chamber 102 or the second chamber 103.

[0131] In this way, by constructing a coordinated control strategy for the air supply component 20, the air extraction component 40, and the hollow fiber membrane bundle, and generating an oxygen concentration change trend curve based on the oxygen concentration change trend in the chamber 80, different oxygen reduction stages are divided according to the slope k of the curve. The first hollow fiber membrane bundle 50 or the second hollow fiber membrane bundle 60 is selected according to different oxygen reduction stages. At the same time, the operating parameters of the air supply component 20 and the air extraction component 40 (including the rotation speed of the air supply component 20 and the working power of the air extraction component 40) are dynamically adjusted to achieve efficient oxygen reduction in different stages. This meets the different requirements of nitrogen and oxygen separation efficiency and moisture resistance in different oxygen reduction stages, takes into account both high separation efficiency and moisture resistance, extends the material service life of the hollow fiber membrane bundle, and also improves the overall system energy efficiency and stability.

[0132] Among them, such as Figure 10 As shown, the oxygen reduction stage is divided according to the slope, and the control method includes:

[0133] When the absolute value of the slope During the deoxygenation stage, which is in the rapid separation zone, the first damper 301 is activated and the second damper 302 is closed.

[0134] When the absolute value of the slope During the oxygen reduction phase, which is in the transition zone, the first damper 301 is activated and the second damper 302 is closed.

[0135] When the absolute value of the slope During the deoxygenation stage, which is in the slow separation zone, the first air damper 301 is closed and the second air damper 302 is activated.

[0136] Please refer to the following table:

[0137]

[0138] This ensures that the deoxygenation device can open different dampers according to different deoxygenation stages, so that the characteristics of the first hollow fiber membrane bundle 50 and the second hollow fiber membrane bundle 60 complement each other, meet the different requirements of nitrogen and oxygen separation efficiency and moisture resistance at different deoxygenation stages, take into account both high separation efficiency and moisture resistance, and extend the material service life of the hollow fiber membrane bundle.

[0139] To ensure that the operating parameters of the air supply component 20 and the air extraction component 40 can be dynamically adjusted through different oxygen reduction stages to achieve a highly efficient and energy-saving oxygen reduction process, the control method includes:

[0140] When the oxygen reduction stage is in the rapid separation zone, the rotation speed of the air supply component 20 is the initial rotation speed n, and the working power of the air extraction component 40 is the initial preset power P.

[0141] When the oxygen reduction stage is in the transition zone, the rotation speed of the air supply component 20 is 2n, and the working power of the air extraction component 40 is 2P.

[0142] When the oxygen reduction stage is in the slow separation zone, the rotation speed of the air supply component 20 is 2n, and the working power of the air extraction component 40 is P.

[0143] The present invention also proposes a computer-readable storage medium storing a computer program / instructions and a bit stream thereon, wherein the computer program / instructions, when executed by a processor, implement the refrigerator and control method described above to generate the bit stream.

[0144] 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 may be implemented in any order unless a specific express order is 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.

[0145] Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus 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 constraints. 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.

[0146] 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. An oxygen-reducing device, characterized in that, include: The housing (10) is divided into an independent first chamber (102) and a second chamber (103) by a first partition (101); an air inlet chamber (104) is provided at the first end of the housing (10) along its axial direction, the air inlet chamber (104) is connected to the front port of the first chamber (102) and the second chamber (103), and an air supply assembly (20) is provided in the air inlet chamber (104); the front port of the first chamber (102) and the second chamber (103) are respectively provided with a damper assembly (30) for controlling the opening and closing of the corresponding chamber with the air inlet chamber (104). The rear ports of the first chamber (102) and the second chamber (103) are provided with a collection chamber (105), and each collection chamber (105) is connected to the air extraction assembly (40); the first chamber (102) and the second chamber (103) are provided with multiple sets of first air outlets (106) along the inner wall of the shell (10) in the thickness direction. The first chamber (102) is provided with a plurality of first hollow fiber membrane bundles (50) extending along the axial direction, and the second chamber (103) is provided with a plurality of second hollow fiber membrane bundles (60) extending along the axial direction; the nitrogen-oxygen separation coefficient and water absorption rate of the second hollow fiber membrane bundles (60) are both greater than those of the first hollow fiber membrane bundles (50). The first hollow fiber membrane bundle (50) and the second hollow fiber membrane bundle (60) have closed structures at their first ends facing the front port, and the second ends of the first hollow fiber membrane bundle (50) and the second hollow fiber membrane bundle (60) are open and communicate with the collection cavity (105).

2. The oxygen reduction device according to claim 1, characterized in that, The damper assembly (30) includes a first damper (301) and a second damper (302); The front port of the first chamber (102) is provided with a first damper (301), which is used to control the connection and disconnection between the first chamber (102) and the air inlet chamber (104); The front port of the second chamber (103) is provided with a second damper (302), which is used to control the connection and disconnection between the second chamber (103) and the air inlet chamber (104); Furthermore, the first damper (301) and the second damper (302) will not be activated simultaneously.

3. The oxygen reduction device according to claim 1, characterized in that, The second chamber (103) is provided with a moisture-absorbing component (70), which is used to perform moisture-absorbing and drying treatment on the inside of the second chamber (103).

4. The oxygen reduction device according to claim 3, characterized in that, The moisture-absorbing component (70) is composed of a solid porous moisture-absorbing material, which includes at least one of metal-organic framework materials, covalent organic framework materials, and porous organic polymers.

5. The oxygen reduction device according to claim 1, characterized in that, The air extraction assembly (40) includes a vacuum pump (401), a first air extraction pipe (402), a second air extraction pipe (403), and a solenoid valve (404). The first chamber (102) is connected to the vacuum pump (401) through the first suction pipe (402); The second chamber (103) is connected to the first suction pipe (402) through the second suction pipe (403), and a solenoid valve (404) is provided at the connection between the first suction pipe (402) and the second suction pipe (403). The solenoid valve (404) is used to selectively open the first suction pipe (402) and close the second suction pipe (403), or close the first suction pipe (402) and open the second suction pipe (403).

6. The oxygen reduction device according to claim 1, characterized in that, The collection cavity (105) is provided with a second partition (107) at the rear port corresponding to the first chamber (102) and the second chamber (103), and the edge of the second partition (107) is sealed to the inner wall of the corresponding chamber. The second ends of all the first hollow fiber membrane bundles (50) and all the second hollow fiber membrane bundles (60) are in contact with the second partition (107), and the contact position of the second partition (107) is provided with a second air outlet (108).

7. The oxygen reduction device according to any one of claims 1 to 6, characterized in that, The first hollow fiber membrane bundle (50) is made of any one of polysulfone, polyethersulfone and cellulose acetate.

8. The oxygen reduction device according to any one of claims 1 to 6, characterized in that, The material used to make the second hollow fiber membrane bundle (60) includes any one of polyimide, polyamide, and polytetrafluoroethylene.

9. A refrigerator comprising at least one compartment (80), characterized in that, The chamber (80) is equipped with an oxygen reduction device as described in any one of claims 1 to 8.

10. The refrigerator according to claim 9, characterized in that, The chamber (80) is also equipped with an oxygen concentration detection device (90), which is used to detect the oxygen concentration in the corresponding chamber (80) in real time.

11. A control method for a refrigerator as described in claim 9 or 10, characterized in that, The control method includes: Place the fruits and vegetables into the compartment (80) of the refrigerator and start the air supply assembly (20) and the air extraction assembly (40). Real-time collection of oxygen concentration parameters in the chamber (80); The collected oxygen concentration parameters are curve-fitted to generate an oxygen concentration change trend curve. Analyze the slope k of the oxygen concentration change trend curve, and divide the oxygen reduction stage according to the slope k; Depending on the different deoxygenation stages, the opening and closing of the damper assembly (30) is controlled so that the airflow delivered by the air supply assembly (20) enters the first chamber (102) or the second chamber (103).

12. The refrigerator control method according to claim 11, characterized in that, The control method includes dividing the oxygen reduction stage according to the slope: When the absolute value of the slope During the deoxygenation stage, which is in the rapid separation zone, the first air damper (301) is activated and the second air damper (302) is closed. When the absolute value of the slope During the oxygen reduction phase, the first air damper (301) is activated and the second air damper (302) is closed. When the absolute value of the slope During the deoxygenation phase, the first air damper (301) is closed and the second air damper (302) is activated.

13. The refrigerator control method according to claim 11 or 12, characterized in that, The control method includes: When the oxygen reduction stage is in the rapid separation zone, the rotation speed of the air supply component (20) is the initial rotation speed n, and the working power of the air extraction component (40) is the initial preset power P. When the oxygen reduction stage is in the transition zone, the rotation speed of the air supply component (20) is 2n, and the working power of the air extraction component (40) is 2P. When the deoxygenation stage is in the slow separation zone, the rotation speed of the air supply component (20) is 2n, and the working power of the air extraction component (40) is P.

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