Air conditioning-temperature and humidity multi-stage collaborative cold chain intelligent preservation system and control method

Abstract

According to the air conditioning-temperature and humidity multi-stage collaborative cold chain intelligent fresh-keeping system and the control method, return air of a container and outdoor fresh air are mixed in proportion, circulating updating of air in the container is achieved, and O2 is supplemented to the needed concentration; then, the concentration of CO2 and C2H4 of the mixed air is precisely regulated and controlled through a gas regulation module, then temperature control is achieved through a refrigeration module, and humidity regulation is conducted through a humidity regulation module; and finally, the goods are uniformly conveyed to a goods storage space through a container air supply pipeline, so that the temperature, humidity and gas components in the container are accurately regulated and controlled. Precise control over the environment in the box is achieved through cascade configuration of fresh air and return air mixing, gas component adjusting, temperature adjusting and humidity adjusting.

Description

Technical Field

[0001] This invention belongs to the field of refrigeration technology, specifically relating to a controlled atmosphere-temperature and humidity multi-level coordinated intelligent cold chain preservation system and control method. Background Technology

[0002] During the transport of fruits and vegetables in refrigerated containers, the refrigeration system precisely regulates the temperature (-18℃~10℃) and humidity (60%~95% RH) inside the container through components such as compressors and evaporators, inhibiting microbial growth and slowing down the metabolism of fruits and vegetables. Modified atmosphere packaging (MAP) technology, on the other hand, dynamically adjusts the concentrations of O2 (1%~5%) and CO2 (1%~10%) to inhibit respiration, and combines this with a catalytic adsorption module to remove ethylene gas, thus slowing down the ripening process. The refrigeration and MAP systems work synergistically to create a low-oxygen, suitable-temperature, and low-ethylene microenvironment for preservation, reducing the respiration intensity of fruits and vegetables and significantly extending their shelf life, thereby effectively solving the problem of quality deterioration during long-distance transportation. Currently, refrigerated containers used in long-distance fruit and vegetable transportation generally adopt a separate design for mechanical refrigeration and modified atmosphere preservation, which presents significant technical bottlenecks: First, conventional modified atmosphere systems rely on independent nitrogen generators or CO2 injection devices, which are energy-intensive and occupy a large space, making it difficult to adapt to the limited on-board power and load restrictions during transportation; Second, existing modified atmosphere technologies mostly use fixed gas ratios, which are difficult to adapt to the fluctuations in the respiratory metabolism of fruits and vegetables and external environmental disturbances in real time when transporting across climate zones, leading to unstable O2 / CO2 concentrations and accelerating the ripening and spoilage of fruits and vegetables.

[0003] Chinese patent application CN 115669719 A discloses a mobile controlled atmosphere refrigeration device that uses a chemical reaction module (a Kipp generator releasing CO2 and a candlestick consuming O2) to replace traditional electric controlled atmosphere equipment. It dynamically controls the O2 / CO2 concentration inside the container through a low-cost, low-energy non-electric drive, making it suitable for transportation in remote areas. However, the Kipp generator's CO2 generation rate is unstable due to temperature and reaction liquid concentration, potentially accelerating fruit and vegetable spoilage. Meanwhile, Chinese patent application CN118882267 A discloses a device and method for ice-temperature controlled atmosphere refrigeration of vegetables. It uses dual fans to accelerate cold air circulation and a spray mechanism to regulate humidity and lower the freezing point, achieving ice-temperature (close to 0°C but not frozen) controlled atmosphere preservation of vegetables and reducing cell damage. However, the dual fans and spray system increase system power consumption, making long-term operation economically unsustainable. Furthermore, humidity control accuracy depends on spray uniformity, easily leading to localized icing or excessive humidity, causing mold growth and other problems. None of the above solutions address the issues of dynamic environmental response and energy recycling, thus limiting their potential for commercialization. Summary of the Invention

[0004] To address the problems of energy redundancy, low space utilization, and insufficient dynamic control capabilities caused by the separate operation of mechanical refrigeration and controlled atmosphere systems in existing refrigerated containers for long-distance transportation of fruits and vegetables, this invention proposes a multi-level coordinated intelligent cold chain preservation system and control method based on controlled atmosphere and temperature and humidity.

[0005] This invention is achieved through the following technical solution: In a first aspect, the present invention provides a multi-level coordinated cold chain intelligent preservation system for controlled atmosphere, temperature and humidity, comprising: a container, a gas conditioning module, a refrigeration module, a humidity conditioning module, a fresh air duct, a return air duct, a supply air duct, a data acquisition module, and a central control unit; the inlet of the return air duct is connected to the internal space of the container, the outlet of the return air duct merges with the outlet of the fresh air duct and is connected to the inlet of the gas conditioning module via a mixing air duct, the outlet of the gas conditioning module is connected to the inlet of the refrigeration module, the outlet of the refrigeration module is connected to the inlet of the humidity conditioning module, and the outlet of the humidity conditioning module is connected to the internal space of the container via the supply air duct; The data acquisition module is used to collect the O2 concentration and mass flow rate of the return air in the return air duct and the O2 concentration of the outside air; and to collect the CO2 concentration, ethylene concentration, temperature and humidity of the mixed air in the mixed air duct and transmit them to the central control unit. The central control unit is used to control the mass flow rate of fresh air in the fresh air duct based on the O2 concentration and mass flow rate of the return air and the O2 concentration of the outside air, so that the O2 concentration of the mixed air reaches the set O2 value; it controls the gas regulating module to adjust the CO2 concentration and ethylene concentration of the mixed air to their respective set values ​​based on the CO2 concentration and ethylene concentration of the mixed air in the mixed air duct; it controls the cooling module to adjust the temperature of the mixed air to the corresponding set value based on the temperature of the mixed air in the mixed air duct; and it controls the humidity regulating module to adjust the humidity of the mixed air to the corresponding set value based on the humidity of the mixed air in the mixed air duct.

[0006] Preferably, the data acquisition module is also used to acquire the O2 concentration of the mixed air in the mixed air duct; The central control unit is also used to control the gas regulating module to adjust the O2 concentration of the mixed air to reach the corresponding set value based on the O2 concentration of the mixed air.

[0007] Furthermore, the gas regulation module includes a deoxygenation device, a CO2 adsorption device, a CO2 generation device, and an ethylene adsorption device; a first gas regulating valve and a deoxygenation device are connected in parallel on the mixing air duct; the outlet of the mixing air duct is connected to the CO2 adsorption device via a second gas regulating valve and to the CO2 generation device via a third gas regulating valve; the outlets of the CO2 adsorption device and the CO2 generation device are connected to the inlet of the ethylene adsorption device; and the outlet of the ethylene adsorption device is connected to the inlet of the refrigeration module.

[0008] Furthermore, the data acquisition module is also used to collect the O2 concentration, CO2 concentration, ethylene concentration, temperature, and humidity of the mixed air in the air supply duct; the central control module is also used to determine whether the O2 concentration, CO2 concentration, ethylene concentration, temperature, and humidity have reached the corresponding set values. If they have not reached the set values, the gas conditioning module, cooling module, and humidity conditioning module are controlled according to the O2 concentration, CO2 concentration, ethylene concentration, temperature, and humidity of the mixed air in the air supply duct.

[0009] Preferably, the refrigeration module includes an evaporator, a compressor, a condenser, a first expansion valve, a second expansion valve, a solenoid valve, and a subcooler; the outlet of the gas regulating module is connected to the refrigerant inlet of the evaporator, the refrigerant outlet of the evaporator is connected to the inlet of the humidity regulating module, and the refrigerant outlet of the evaporator is connected to the inlet of the condenser via the compressor; the outlet of the condenser is divided into two paths, one connected to the hot fluid inlet of the subcooler, and the other connected to the cold fluid inlet of the subcooler via the first expansion valve; the hot fluid outlet of the subcooler is connected to the refrigerant inlet of the evaporator via the second expansion valve; and the cold fluid outlet of the subcooler is connected to the compressor via the solenoid valve.

[0010] Preferably, the humidity control module includes a first humidity control valve, a second humidity control valve, a humidifier, and a dehumidifier; the outlet of the refrigeration module is connected to the inlet of the humidifier via the first humidity control valve and to the inlet of the dehumidifier via the second humidity control valve; the outlets of the humidifier and the dehumidifier are connected to the inlet of the air supply duct.

[0011] Preferably, the inlet of the fresh air duct is connected to an air filter and a fresh air regulating valve.

[0012] Secondly, the present invention provides a control method for the aforementioned controlled atmosphere-temperature and humidity multi-level coordinated intelligent cold chain preservation system, comprising: The data acquisition module collects the O2 concentration and mass flow rate of the return air in the return air duct and the O2 concentration of the outside air, and collects the CO2 concentration, ethylene concentration, temperature and humidity of the mixed air in the mixed air duct, and transmits them to the central control unit. The central control unit controls the mass flow rate of fresh air in the fresh air duct based on the O2 concentration and mass flow rate of the return air and the O2 concentration of the outside air, so that the O2 concentration of the mixed air reaches the set O2 value. The gas regulation module adjusts the CO2 concentration and ethylene concentration of the mixed air to their respective set values ​​based on the CO2 concentration and ethylene concentration of the mixed air in the mixed air duct. The cooling module adjusts the temperature of the mixed air to its corresponding set value based on the temperature of the mixed air in the mixed air duct. The humidity regulation module adjusts the humidity of the mixed air to its corresponding set value based on the humidity of the mixed air in the mixed air duct.

[0013] Preferably, the control method of the aforementioned controlled atmosphere-temperature and humidity multi-level coordinated cold chain intelligent preservation system utilizes a data acquisition module to collect the O2 concentration of the mixed air in the mixed air duct; The central control unit uses the gas regulation module to adjust the O2 concentration of the mixed air to the corresponding set value based on the O2 concentration of the mixed air.

[0014] Preferably, the control method of the aforementioned controlled atmosphere-temperature and humidity multi-level coordinated intelligent cold chain preservation system utilizes a data acquisition module to collect the O2 concentration, CO2 concentration, ethylene concentration, temperature, and humidity of the mixed air in the air supply duct; and uses a central control module to determine whether the O2 concentration, CO2 concentration, ethylene concentration, temperature, and humidity have reached the corresponding set values. If they have not been reached, the gas conditioning module, refrigeration module, and humidity conditioning module are controlled to continue adjusting based on the O2 concentration, CO2 concentration, ethylene concentration, temperature, and humidity of the mixed air in the air supply duct.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The multi-level collaborative intelligent preservation system proposed in this invention has the following workflow: First, the return air from the container is mixed with the fresh outdoor air in a certain proportion to achieve the circulation and renewal of the gas inside the container, replenishing O2 to the required concentration; then, the mixed air is precisely regulated by the gas regulation module to control the concentration of CO2 and C2H4, and then sequentially passes through the refrigeration module to achieve temperature control (accuracy of ±0.5℃) and the humidity regulation module to adjust the humidity (RH ±3% adjustable); finally, it is evenly delivered to the cargo storage space through the container's air supply duct, achieving precise control of the temperature, humidity and gas composition inside the container. This invention adopts a tiered configuration of "fresh and return air mixing - gas component adjustment - temperature adjustment - humidity adjustment" to achieve precise control of the environment inside the container. The main advantages are as follows: (1) Improve system efficiency. The tiered configuration of the intelligent preservation system can not only reduce additional power consumption, but also improve system energy efficiency. If the gas adjustment module is placed at the end, the refrigeration module and humidity adjustment module will need to consume more energy to cope with the temperature and humidity fluctuations caused by the gas adjustment module; (2) Enhance system stability. By adjusting the proportion of fresh air outside the container, the oxygen concentration of the mixed air is kept within the ideal range. This method effectively delays the respiration of fruits and vegetables, reduces the fluctuation of oxygen concentration, and reduces the workload of the gas adjustment module, thereby improving the energy efficiency and operational stability of the entire system; (3) Significantly improve humidity control accuracy. Placing the temperature adjustment device before the humidity adjustment device can reduce the effect of the evaporator 16 in the temperature adjustment device on the humidity of the air inside the container, and achieve precise control of humidity. (4) The scheme based on the comprehensive control of "gas composition-temperature-humidity" can effectively cope with external disturbances (such as temperature and humidity fluctuations and altitude changes) and the dynamic changes in the respiration and metabolism of fruits and vegetables, so as to adapt to changes in the external environment and ensure that the gas composition, temperature and humidity in the box are always maintained within a reasonable range, ensuring that fruits and vegetables are stored under ideal preservation conditions of low oxygen, low ethylene and constant temperature and humidity. This scheme significantly improves the system response speed and stability, optimizes the modified atmosphere effect, effectively extends the shelf life of fruits and vegetables, and reduces losses.

[0016] Furthermore, to avoid situations where the O2 concentration cannot be achieved by mixing fresh and return air under special circumstances, this invention also uses a gas regulation module to adjust the O2 concentration of the mixed air to reach the corresponding set value, thereby further ensuring that the O2 concentration of the mixed air entering the container reaches the set value, so as to ensure ideal preservation conditions as much as possible. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart of the intelligent cold chain preservation system of the present invention; Figure 2 This is a schematic diagram of the intelligent cold chain preservation system of the present invention; Figure 3 This is a control principle diagram of the intelligent cold chain preservation system of the present invention; In the diagram: 1. Fresh air duct; 2. Return air duct; 3. Gas regulation module; 4. Refrigeration module; 5. Humidity regulation module; 6. Supply air duct; 7. Container; 8. Mixing air duct; 9. First gas regulating valve; 10. Deoxygenation device; 11. CO2 adsorption device; 12. CO2 generation device; 13. Ethylene adsorption device; 14. Second gas regulating valve; 15. Third gas regulating valve; 16. Evaporator; 17. Compressor; 18. Condenser; 19. First expansion valve; 20. Second expansion valve; 21. Solenoid valve; 22. Subcooler; 23. First humidity regulating valve; 24. Second humidity regulating valve; 25. Humidifier; 26. Dehumidifier; 27. Fresh air regulating valve; 28. First air filter; 29. ​​Second air filter; 30. Third air filter; 31. Fourth air filter; 32. Fifth air filter. Detailed Implementation

[0019] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0020] It should be noted that the process equipment or apparatus not specifically mentioned in the following embodiments are all conventional equipment or apparatus in the art.

[0021] It should be noted that the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or apparatuses. Furthermore, unless otherwise stated, the numbering of each method step is merely a convenient tool for identifying each method step, and not intended to limit the order of the method steps or define the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0022] Furthermore, it should be noted that the terms "first," "second," etc., used in this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Moreover, unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly, for example, referring to a fixed connection or a detachable connection; a direct connection or an indirect connection via an intermediate medium; or a connection within two components.

[0023] like Figure 1 As shown, the cold chain intelligent preservation system of the present invention, which is a multi-level coordinated system of controlled atmosphere, temperature and humidity, includes a container 7, a gas conditioning module 3, a refrigeration module 4, a humidity conditioning module 5, a fresh air duct 1, a return air duct 2, a supply air duct 6, a data acquisition module, and a central control unit. The inlet of the return air duct 2 is connected to the internal space of the container 7. The outlet of the return air duct 2 merges with the outlet of the fresh air duct 1 and is connected to the inlet of the gas conditioning module 3 via a mixing air duct 8. The outlet of the gas conditioning module 3 is connected to the inlet of the refrigeration module 4. The outlet of the refrigeration module 4 is connected to the inlet of the humidity conditioning module 5. The outlet of the humidity conditioning module 5 is connected to the internal space of the container 7 via the supply air duct 6.

[0024] The data acquisition module is used to collect the O2 concentration and mass flow rate of the return air in the return air duct 2 and the O2 concentration of the outside air; and to collect the CO2 concentration, ethylene concentration, temperature and humidity of the mixed air in the mixed air duct 8 and transmit them to the central control unit.

[0025] The central control unit is used to control the mass flow rate of fresh air in the fresh air duct 1 according to the O2 concentration and mass flow rate of the return air and the O2 concentration of the outside air, so that the O2 concentration of the mixed air reaches the set O2 value; to control the gas regulating module 3 to adjust the CO2 concentration and ethylene concentration in the mixed air to their respective set values ​​according to the CO2 concentration and ethylene concentration in the mixed air in the mixed air duct 8; to control the cooling module 4 to adjust the temperature of the mixed air to the corresponding set value according to the temperature of the mixed air in the mixed air duct 8; and to control the humidity regulating module 5 to adjust the humidity of the mixed air to the corresponding set value according to the humidity of the mixed air in the mixed air duct 8.

[0026] Container 7 is the basic structure of the entire intelligent cold chain preservation system, mainly used for the storage and transportation of goods. Container 7 has good thermal insulation performance, which can effectively isolate the influence of the external environment and provide the necessary space and environment for internal controlled atmosphere and temperature and humidity control.

[0027] The gas regulation module 3 adjusts the ratio of oxygen (O2), carbon dioxide (CO2), and ethylene (C2H4) to ensure that fruits and vegetables maintain a suitable respiration state during transportation, slow down their metabolic rate, and thus extend their shelf life.

[0028] The refrigeration module 4 is used to maintain the temperature inside the container 7 within the optimal range (typically -18°C in freezing mode and 0°C to 10°C in fresh-keeping mode) through mechanical refrigeration technology, preventing fruits and vegetables from spoiling prematurely due to excessively high temperatures. This refrigeration module 4 can achieve a temperature control accuracy of ±0.5°C, ensuring temperature stability.

[0029] The humidity control module 5 is used to maintain a suitable humidity inside the container 7 through humidification and dehumidification functions (RH ± 3% adjustable) to prevent fruits and vegetables from losing water or rotting due to excessive humidity. This humidity control module 5 works in conjunction with the gas control module 3 and the refrigeration module 4 to optimize the overall preservation effect.

[0030] The fresh air duct 1 is used to introduce fresh external air, ensuring the gas inside container 7 is refreshed. In conjunction with the return air duct 2, gas circulation is achieved, maintaining the vitality of the environment inside container 7 and enhancing the storage effect of fruits and vegetables. The return air duct 2 introduces the gas inside container 7 into the gas conditioning module 3 for reprocessing and circulation. This step ensures efficient air utilization, reduces energy waste, and maintains the stability of the gas composition inside container 7. The supply air duct 6 is responsible for evenly distributing the regulated gas inside container 7, ensuring that each storage area maintains relatively consistent climatic conditions, further optimizing the preservation environment for fruits and vegetables. Through close collaboration among the various modules of the cold chain intelligent preservation system, perishable goods such as fruits and vegetables are stored in optimal condition during transportation.

[0031] To avoid situations where the oxygen content in the outside air is too high, making it difficult to adjust the fresh air mass flow rate to achieve the set oxygen concentration in the mixed air, this invention also collects the O2 concentration of the mixed air in the mixed air duct 8 through a data acquisition module; the central control unit controls the gas regulation module 3 to adjust the O2 concentration of the mixed air to the corresponding set value based on the O2 concentration of the mixed air.

[0032] In some embodiments of the present invention, a fresh air regulating valve 27 and a first air filter device 28 are provided on the fresh air duct, the first air filter device 28 filtering and removing impurities from the fresh air outside the chamber. A second air filter device 29 is provided on the mixed air duct 8.

[0033] In some embodiments of the present invention, the gas regulating module 3 includes a deoxygenation device 10, a CO2 adsorption device 11, a CO2 generation device 12, and an ethylene adsorption device 13; a first gas regulating valve 9 and a deoxygenation device 10 are connected in parallel on the mixing air duct 8; the outlet of the mixing air duct 8 is connected to the CO2 adsorption device 11 via a second gas regulating valve 14 and to the CO2 generation device 12 via a third gas regulating valve 15; the outlets of the CO2 adsorption device 11 and the CO2 generation device 12 are connected to the inlet of the ethylene adsorption device 13; and the outlet of the ethylene adsorption device 13 is connected to the inlet of the refrigeration module 4 via a third air filter 30.

[0034] In some embodiments of the present invention, the refrigeration module 4 adopts a gas-fuel enthalpy-increasing refrigeration system, including an evaporator 16, a compressor 17, a condenser 18, a first expansion valve 19, a second expansion valve 20, a solenoid valve 21, and a subcooler 22; the outlet of the gas regulating module 3 is connected to the refrigerant (here referring to mixed air) inlet of the evaporator 16, the refrigerant outlet of the evaporator 16 is connected to the inlet of the humidity regulating module 5 via a fourth air filter 31, and the refrigerant outlet of the evaporator 16 is connected to the inlet of the condenser 18 via the compressor 17; the outlet of the condenser 18 is divided into two paths, one path is connected to the hot fluid inlet of the subcooler 22, and the other path is connected to the cold fluid inlet of the subcooler 22 via the first expansion valve 19, the hot fluid outlet of the subcooler 22 is connected to the refrigerant inlet of the evaporator 16 via the second expansion valve 20; the cold fluid outlet of the subcooler 22 is connected to the compressor 17 via the solenoid valve 21.

[0035] In some embodiments of the present invention, the humidity regulating module 5 includes a first humidity regulating valve 23, a second humidity regulating valve 24, a humidifying device 25, and a dehumidifying device 26; the outlet of the refrigeration module 4 is connected to the inlet of the humidifying device 25 via the first humidity regulating valve 23 and to the inlet of the dehumidifying device 26 via the second humidity regulating valve 24; the outlets of the humidifying device 25 and the dehumidifying device 26 are connected to the inlet of the air supply duct 6 via the fifth air filter 32.

[0036] The main working principles of each module of the intelligent cold chain preservation system are as follows: Figure 2 As shown, firstly, the return air and fresh air in container 7 are mixed in a certain proportion. The fresh air is used to adjust the O2 concentration in the gas inside container 7 to ensure gas circulation and maintain a good gas environment. The mixing ratio of return air and fresh air is described by formula (1).

[0037]

[0038] in, The mass flow rate of the return air. The O2 concentration in the return air. The mass flow rate of fresh air in fresh air duct 1. The O2 concentration of fresh air, This is the set value for O2 concentration.

[0039] The mixed gas passes through an air filter and enters the gas conditioning module 3, flowing sequentially through the deoxygenation device 10, the CO2 generation / adsorption device, and the C2H4 adsorption device. The ratio of O2, CO2, and C2H4 is dynamically and precisely controlled to adapt to the metabolic changes of fruits and vegetables during transportation, ensuring optimal storage conditions. Subsequently, the mixed air passes through the evaporator 16 of the refrigeration module 4 and the humidity conditioning module 5. In the refrigeration module 4, the onboard power drives the compressor 17, where the refrigerant exchanges heat with the outdoor air in the condenser 18 and cools the mixed air in the evaporator 16, releasing cold energy to maintain a suitable temperature range for fruit and vegetable storage. Simultaneously, the humidity conditioning module 5 has a dual-effect humidity control function (RH±3% adjustable), effectively preventing rotting or water loss due to improper humidity. The dual-effect humidity control function means that the humidity conditioning module 5 has two different adjustment mechanisms: humidification and dehumidification. When the humidity of the mixed air is lower than the set value, the system automatically activates the humidification device 25 to add water to the mixed air to increase the relative humidity. RH When the humidity of the mixed air exceeds the set value, the system activates the dehumidifier 26 to remove excess moisture from the mixed air, thereby reducing the relative humidity. The regulated mixed air is evenly distributed to the cargo storage space through the air duct 6 at the bottom of container 7, ensuring uniform temperature and humidity distribution throughout the container. This process significantly reduces temperature and humidity unevenness, ensuring the overall quality of the goods and minimizing losses caused by unsuitable local environments. By comprehensively regulating the gas composition, temperature, and humidity of the mixed air, an efficient and flexible preservation environment is created, improving energy utilization and enhancing the dynamic control over the storage status of fruits and vegetables, thus achieving longer shelf life and lower loss rates. This innovative cold chain preservation technology provides strong support for the sustainable development of modern logistics systems.

[0040] To address the issues of fixed gas composition and slow environmental control response in traditional controlled atmosphere storage technologies, this invention innovatively proposes a dynamic integrated control scheme based on gas composition, temperature, and humidity. By integrating data acquisition modules from multiple high-precision sensors, the temperature, humidity, and concentration of key gases (O2, CO2, C2H4) in the mixed air are monitored in real time. The central control unit dynamically adjusts the ratio of fresh air to return air, precisely driving the deoxygenation, CO2 adsorption device 11 / generation device 12, and ethylene adsorption device 13. Combined with an advanced refrigeration and dual-effect humidity control module 5, comprehensive real-time control of the storage environment is achieved.

[0041] The control principle of the system of this invention is as follows: Figure 3 As shown, the specific control logic is as follows: (1) Monitoring phase: A data acquisition module composed of multiple sensors collects the O2 concentration and mass flow rate of the return air and the O2 concentration of the outside air in real time; and collects the CO2 concentration, ethylene concentration, temperature and relative humidity of the mixed air in the mixed air duct 8. RH The data is transmitted to the central control unit via the data acquisition module.

[0042] (2) Gas mixing and regulation control: Based on the set O2 concentration setting value and the actual O2 concentration value collected, the required fresh air volume is calculated, and the mixing ratio of fresh air and return air is dynamically adjusted according to formula (1); the mixed gas is first purified by an air filter device, and then enters the gas regulation module 3. The gas regulation module 3 achieves precise dynamic regulation of the mixed air components by precisely controlling the deoxygenation device 10, CO2 generation device 12, CO2 adsorption device 11 and ethylene adsorption device 13.

[0043] (3) Temperature regulation and control: Calculate the deviation between the temperature setpoint and the collected mixed air temperature, start the refrigeration module 4, adjust the speed of the compressor 17 to control the refrigerant circulation, and cool the mixed air through the evaporator 16 to maintain the set constant temperature range (±0.5℃).

[0044] (4) Humidity regulation and control: Calculate the deviation between the humidity setpoint and the mixed air humidity, start the humidity module, and when the mixed air humidity is lower than the humidity setpoint, start the humidifier 25 to replenish water; when the mixed air humidity is higher than the humidity setpoint, start the dehumidifier 26 to remove excess water. By dynamically adjusting the ratio of the opening of the humidity regulating valves in front of the humidifier 25 and the dehumidifier 26, precise humidity control can be achieved.

[0045] (5) Uniform control of gas delivery: Adjust the fan speed to ensure that the gas is evenly distributed to the cargo storage space inside the container 7 through the bottom air supply pipe 6; monitor the temperature and humidity uniformity of each area inside the container 7 in real time, and dynamically adjust the fan parameters to reduce local environmental differences.

[0046] (6) Finally, monitor whether the O2 concentration, CO2 concentration, ethylene concentration, temperature and humidity of the mixed air after treatment have reached their respective set values. If they have, the control is complete. If they have not, restart the intelligent preservation system and treat the air again until the set requirements are met.

[0047] This control logic ensures that the system dynamically and precisely adjusts the gas composition, temperature, and humidity according to the real-time environment and the condition of the fruits and vegetables, creating a stable and efficient preservation environment, extending the shelf life of fruits and vegetables, and reducing losses.

[0048] The aforementioned intelligent cold chain preservation system plays a crucial role in improving the transportation efficiency and preservation quality of perishable goods such as fruits and vegetables. By precisely controlling gas composition, temperature, and humidity, the system can effectively extend shelf life, reduce spoilage rates, and ensure the freshness and quality of goods during transportation. Simultaneously, the system's high efficiency and flexibility not only improve energy utilization but also reduce resource waste, promoting the development of sustainable logistics and possessing significant social and economic value in ensuring food safety and meeting market demands.

Claims

1. A controlled atmosphere-temperature and humidity multi-level coordinated intelligent cold chain preservation system, characterized in that, include: The container (7), gas conditioning module (3), refrigeration module (4), humidity conditioning module (5), fresh air duct (1), return air duct (2), supply air duct (6), data acquisition module and central control unit; the inlet of the return air duct (2) is connected to the internal space of the container (7), the outlet of the return air duct (2) merges with the outlet of the fresh air duct (1) and is connected to the inlet of the gas conditioning module (3) via the mixing air duct (8), the outlet of the gas conditioning module (3) is connected to the inlet of the refrigeration module (4), the outlet of the refrigeration module (4) is connected to the inlet of the humidity conditioning module (5), and the outlet of the humidity conditioning module (5) is connected to the internal space of the container (7) via the supply air duct (6); The data acquisition module is used to collect the O2 concentration and mass flow rate of the return air in the return air duct (2) and the O2 concentration of the outside air; and to collect the CO2 concentration, ethylene concentration, temperature and humidity of the mixed air in the mixed air duct (8) and transmit them to the central control unit. The central control unit is used to control the mass flow rate of fresh air in the fresh air duct (1) according to the O2 concentration and mass flow rate of the return air and the O2 concentration of the outside air, so that the O2 concentration of the mixed air reaches the O2 set value; according to the CO2 concentration and ethylene concentration of the mixed air in the mixed air duct (8), the gas regulating module (3) is used to adjust the CO2 concentration and ethylene concentration of the mixed air to their respective set values; according to the temperature of the mixed air in the mixed air duct (8), the cooling module (4) is used to adjust the temperature of the mixed air to the corresponding set value; according to the humidity of the mixed air in the mixed air duct (8), the humidity regulating module (5) is used to adjust the humidity of the mixed air to the corresponding set value.

2. The controlled atmosphere-temperature and humidity multi-level coordinated intelligent cold chain preservation system according to claim 1, characterized in that, The data acquisition module is also used to collect the O2 concentration of the mixed air in the mixed air duct (8); The central control unit is also used to control the gas regulating module (3) to adjust the O2 concentration of the mixed air to the corresponding set value according to the O2 concentration of the mixed air.

3. The controlled atmosphere-temperature and humidity multi-level synergistic cold chain intelligent preservation system according to claim 2, characterized in that, The gas regulation module (3) includes a deoxygenation device (10), a CO2 adsorption device (11), a CO2 generation device (12), and an ethylene adsorption device (13); the mixing air duct (8) is connected in parallel with a first gas regulating valve (9) and a deoxygenation device (10). The outlet of the mixing air duct (8) is connected to the CO2 adsorption device (11) via a second gas regulating valve (14) and to the CO2 generation device (12) via a third gas regulating valve (15). The outlets of the CO2 adsorption device (11) and the CO2 generation device (12) are connected to the inlet of the ethylene adsorption device (13). The outlet of the ethylene adsorption device (13) is connected to the inlet of the refrigeration module (4).

4. The controlled atmosphere-temperature and humidity multi-level synergistic intelligent cold chain preservation system according to claim 2, characterized in that, The data acquisition module is also used to collect the O2 concentration, CO2 concentration, ethylene concentration, temperature and humidity of the mixed air in the air supply duct (6); the central control module is also used to determine whether the O2 concentration, CO2 concentration, ethylene concentration, temperature and humidity have reached the corresponding set values. If they have not reached the set values, the gas regulation module (3), the refrigeration module (4) and the humidity regulation module (5) are controlled according to the O2 concentration, CO2 concentration, ethylene concentration, temperature and humidity of the mixed air in the air supply duct (6).

5. The controlled atmosphere-temperature and humidity multi-level coordinated intelligent cold chain preservation system according to claim 1, characterized in that, The refrigeration module (4) includes an evaporator (16), a compressor (17), a condenser (18), a first expansion valve, a second expansion valve (20), a solenoid valve (21), and a subcooler (22). The outlet of the gas regulating module (3) is connected to the refrigerant inlet of the evaporator (16), the refrigerant outlet of the evaporator (16) is connected to the inlet of the humidity regulating module (5), and the refrigerant outlet of the evaporator (16) is connected to the inlet of the condenser (18) via the compressor (17). The outlet of the condenser (18) is divided into two paths: one path is connected to the hot fluid inlet of the subcooler (22), and the other path is connected to the cold fluid inlet of the subcooler (22) via the first expansion valve. The hot fluid outlet of the subcooler (22) is connected to the refrigerant inlet of the evaporator (16) via the second expansion valve (20). The cold fluid outlet of the subcooler (22) is connected to the compressor (17) via the solenoid valve (21).

6. The controlled atmosphere-temperature and humidity multi-level coordinated intelligent cold chain preservation system according to claim 1, characterized in that, The humidity control module (5) includes a first humidity control valve (23), a second humidity control valve, a humidifier (25), and a dehumidifier (26); the outlet of the refrigeration module (4) is connected to the inlet of the humidifier (25) via the first humidity control valve (23) and to the inlet of the dehumidifier (26) via the second humidity control valve; the outlets of the humidifier (25) and the dehumidifier (26) are connected to the inlet of the air supply duct (6).

7. The controlled atmosphere-temperature and humidity multi-level coordinated intelligent cold chain preservation system according to claim 1, characterized in that, The inlet of the fresh air duct (1) is connected to an air filter and a fresh air regulating valve (27).

8. The control method of the controlled atmosphere-temperature and humidity multi-level coordinated intelligent cold chain preservation system as described in claim 1, characterized in that, include: The data acquisition module collects the O2 concentration and mass flow rate of the return air in the return air duct (2) and the O2 concentration of the outside air, and collects the CO2 concentration, ethylene concentration, temperature and humidity of the mixed air in the mixed air duct (8) and transmits them to the central control unit. The central control unit controls the mass flow rate of fresh air in the fresh air duct (1) based on the O2 concentration and mass flow rate of the return air and the O2 concentration of the outside air, so that the O2 concentration of the mixed air reaches the O2 set value; the gas regulating module (3) adjusts the CO2 concentration and ethylene concentration in the mixed air to their respective set values ​​based on the CO2 concentration and ethylene concentration in the mixed air duct (8); the cooling module (4) adjusts the temperature of the mixed air to the corresponding set value based on the temperature of the mixed air in the mixed air duct (8); and the humidity regulating module (5) adjusts the humidity of the mixed air to the corresponding set value based on the humidity of the mixed air in the mixed air duct (8).

9. The control method of the controlled atmosphere-temperature and humidity multi-level coordinated intelligent cold chain preservation system according to claim 8, characterized in that, The O2 concentration of the mixed air in the mixed air duct (8) was collected using the data acquisition module; The central control unit controls the gas regulation module (3) to adjust the O2 concentration of the mixed air to the corresponding set value based on the O2 concentration of the mixed air.

10. The control method of the controlled atmosphere-temperature and humidity multi-level coordinated intelligent cold chain preservation system according to claim 8, characterized in that, The data acquisition module collects the O2 concentration, CO2 concentration, ethylene concentration, temperature and humidity of the mixed air in the air supply duct (6); the central control module determines whether the O2 concentration, CO2 concentration, ethylene concentration, temperature and humidity have reached the corresponding set values. If they have not reached the set values, the gas regulation module (3), the refrigeration module (4) and the humidity regulation module (5) are controlled according to the O2 concentration, CO2 concentration, ethylene concentration, temperature and humidity of the mixed air in the air supply duct (6) to continue to adjust.

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