Modified atmosphere fresh-keeping process and system for sealed tobacco leaves
By precisely controlling the concentrations of oxygen, nitrogen, and carbon dioxide, as well as temperature and humidity, within sealed tunnels, and employing a PID algorithm to create an inert gas environment, the problem of quality degradation during tobacco storage was solved, achieving a highly efficient preservation effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-12
- Publication Date
- 2026-04-03
AI Technical Summary
Existing technologies cannot effectively prevent the aging reaction from continuing during tobacco storage, leading to a decline in tobacco quality, especially irreversible quality loss during long-term storage.
By precisely controlling the oxygen, nitrogen, and carbon dioxide concentrations within the sealed tunnel, and combining this with temperature and humidity, a PID control algorithm is employed to achieve dynamic adjustment, creating an inert gas environment to suppress oxidation reactions.
It effectively prevents the deterioration of tobacco leaf quality, maintains stable physicochemical indicators and sensory quality, resolves the contradiction between long-term storage and quality maintenance, and improves the utilization rate and economic benefits of tobacco leaves.
Smart Images
Figure CN121774253A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of tobacco production technology, and to a modified atmosphere preservation process and system for sealing tobacco leaves. Background Technology
[0002] The aging of tobacco leaves is essentially a series of slow, oxidation-based biochemical processes that occur under suitable conditions, aiming to improve their sensory qualities (such as aroma, taste, and color). However, once aging reaches the optimal point preset by the process (i.e., "aging in place"), if production cannot be started in time for tobacco processing due to scheduling or other reasons, this biochemical process will not automatically stop. Under normal storage conditions, the tobacco leaves will continue to age, gradually entering an "over-aging" state, leading to an irreversible decline in their core quality indicators. Specifically, this manifests as the dissipation of elegant aroma, a reduction in aroma intensity, a darker brown color, increased irritation, and reduced usability, resulting in a devaluation of the expensive raw material.
[0003] Currently, the industry generally relies on traditional temperature and humidity control technologies for the long-term storage of aged tobacco leaves. These technologies mainly use air conditioning and humidification / dehumidification equipment to maintain the warehouse environment within a certain temperature and humidity range (e.g., temperature 22±2°C, relative humidity 60±5%). While this method can delay mold and pests to some extent and slow down some physical changes, in normal air (oxygen content of about 21%), as long as the temperature and humidity are suitable, the oxidation reaction will continue, making it impossible to truly "preserve" or "pause aging." Especially when facing seasonal changes, fluctuations in local warehouse environments, or storage periods of several months to several years, relying solely on temperature and humidity control is insufficient. The tobacco leaves will still gradually deteriorate due to slow but continuous oxidation, and the long-term aging investment made by enterprises in pursuit of high quality faces the risk of loss. Summary of the Invention
[0004] This application provides a modified atmosphere storage process and system for sealing tobacco leaves, aiming to solve the above-mentioned problems.
[0005] One approach provides a modified atmosphere packaging process for sealing tobacco leaves, comprising the following steps: S1. Obtain information on the tobacco leaves to be preserved, the gas information, temperature information, and humidity information in the sealed tunnel; S2. Obtain the adjustment parameters based on the information obtained in step S1; S3. Based on the adjustment parameters and the adjustment algorithm, obtain execution data for adjusting the gas type and corresponding content value in the sealed tunnel, and the temperature and humidity in the tunnel within the set range; S4. Based on the execution data, the execution mechanism performs the corresponding action.
[0006] In one embodiment, the gas type in the adjustment parameters includes nitrogen, oxygen, and carbon dioxide; the oxygen concentration is set within a range of 0.1%-0.5%, the carbon dioxide concentration within a range of 1%-5%, the nitrogen concentration within a range of 94.5%-98.9%, the temperature within a range of 15-25°C, and the humidity within a range of 55-65%.
[0007] The adjustment parameters include preset gas types, target concentrations, target temperature values, and target humidity values based on the tobacco leaf information. These gas types, target concentrations, target temperature values, and target humidity values are all pre-stored by the user in corresponding tables. Finding the acquired tobacco leaf information will retrieve the corresponding gas types, target concentrations, target temperature values, and target humidity values.
[0008] In one scheme, the information of the tobacco leaves to be preserved, the gas information in the sealed tunnel, the temperature information, and the humidity information are respectively obtained by the user inputting or scanning barcodes or QR codes, and by the oxygen concentration sensor, the carbon dioxide concentration sensor, the nitrogen concentration sensor, the temperature sensor, and the humidity sensor.
[0009] In one embodiment, the actuator includes an intake valve and an exhaust valve communicating with the sealed tunnel, and also includes a humidity regulator and an air conditioner disposed within the sealed tunnel.
[0010] In one scheme, the adjustment algorithm calculates the flow rate of each gas using the following formula:
[0011] in, The flow rate of oxygen or carbon dioxide; , , For PID parameters; This refers to the gas content value detected by the corresponding sensor for oxygen or carbon dioxide. The corresponding adjustment parameter value is for oxygen or carbon dioxide.
[0012] In one scheme, establish , , The value of [value] is related to the tobacco leaf type, gas content, humidity, and temperature; the appropriate value should be selected based on the specific circumstances. , , value.
[0013] In one embodiment, another aspect provides a modified atmosphere packaging system for sealing tobacco leaves, comprising: A sealed tunnel for containing tobacco leaves to be preserved; A data acquisition module is installed inside the sealed tunnel. The data acquisition module is electrically connected to the processing module. An execution module is electrically connected to the processing module.
[0014] In one embodiment, the processing module is a PLC controller, and the adjustment algorithm is built into the processing module.
[0015] In one embodiment, an alarm module is also included, which is electrically connected to the processing module.
[0016] In one embodiment, a human-computer interaction interface is also included, which is electrically connected to the processing module.
[0017] The beneficial effects of this application are: By precisely controlling and maintaining the oxygen concentration within the sealed tunnel at an extremely low level (e.g., 0.1%-0.5%), key biochemical reactions that lead to the deterioration of tobacco leaf quality, such as oxidation and enzymatic browning, are effectively limited. This not only effectively prevents the "over-aging" of tobacco leaves that have already reached the desired aging stage, but also keeps their main physicochemical indicators and sensory quality stable at their optimal state for a long period, resolving the contradiction between long-term storage and quality maintenance.
[0018] The "adjustment algorithm" does not use fixed parameters. Instead, it establishes a mapping model based on "tobacco leaf type to process parameters." Based on the input tobacco leaf information (such as variety, origin, and grade), it matches or allows operators to define corresponding target gas concentration ranges (O2, CO2), temperature, humidity, and core control parameters (such as PID parameters). Whether it's highly aromatic flue-cured tobacco requiring extremely low oxygen, tobacco stems that allow slightly higher oxygen levels, or reconstituted tobacco leaves with special respiration rates, it can provide personalized preservation solutions, achieving refined management with a "one-size-fits-one" approach and strong versatility.
[0019] By employing a combination of dense shelving and sealed aisle storage, high-density storage was achieved. Simultaneously, precise controlled atmosphere storage extended the optimal shelf life of the tobacco leaves, allowing companies to flexibly adjust production according to market demand. This reduced losses due to raw material spoilage, improved the utilization rate of high-value tobacco leaves, and resulted in significant overall economic benefits. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 This is a schematic diagram of a modified atmosphere preservation process according to an embodiment of this application; Figure 2 This is a schematic diagram of the process of obtaining and adding nitrogen into a sealed tunnel according to an embodiment of this application; Figure 3 This is a schematic diagram of the control flow of a modified atmosphere preservation system according to an embodiment of this application; Figure 4 This is a schematic diagram of the adjustment algorithm architecture according to an embodiment of this application; Labels for each item in the figure: 1. Data acquisition module; 2. Processing module; 3. Execution module; 4. Alarm module; 5. Human-machine interface. Detailed Implementation
[0022] The specific embodiments of this application will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this application, but are not intended to limit the scope of this application. Similarly, the following examples are only some embodiments of this application, not all embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0023] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0025] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0026] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0027] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0028] This application proposes improvements and innovations, and presents the following embodiments.
[0029] In some implementations, please refer to Figures 1 to 4 One aspect is the provision of a modified atmosphere packaging process for sealing tobacco leaves, which includes the following steps: S1. Obtain information on the tobacco leaves to be preserved, the gas information, temperature information, and humidity information in the sealed tunnel; S2. Obtain the adjustment parameters based on the information obtained in step S1; S3. Based on the adjustment parameters and the adjustment algorithm, obtain the execution data for adjusting the gas type and corresponding content value in the sealed roadway, and the temperature and humidity in the roadway within the set range; S4. Based on the execution data, the execution agency performs the corresponding actions.
[0030] By precisely controlling and maintaining the oxygen concentration within the sealed tunnel at an extremely low level (e.g., 0.1%-0.5%), key biochemical reactions that lead to the deterioration of tobacco leaf quality, such as oxidation and enzymatic browning, are effectively limited. This not only effectively prevents the "over-aging" of tobacco leaves that have already reached the desired aging stage, but also keeps their main physicochemical indicators and sensory quality stable at their optimal state for a long period, resolving the contradiction between long-term storage and quality maintenance.
[0031] The "adjustment algorithm" does not use fixed parameters. Instead, it establishes a mapping model based on "tobacco leaf type to process parameters." Based on the input tobacco leaf information (such as variety, origin, and grade), it matches or allows operators to define corresponding target gas concentration ranges (O2, CO2), temperature, humidity, and core control parameters (such as PID parameters). Whether it's highly aromatic flue-cured tobacco requiring extremely low oxygen, tobacco stems that allow slightly higher oxygen levels, or reconstituted tobacco leaves with special respiration rates, it can provide personalized preservation solutions, achieving refined management with a "one-size-fits-one" approach and strong versatility.
[0032] In one embodiment, the gas type in the adjustment parameters includes nitrogen, oxygen, and carbon dioxide; the oxygen concentration is set within a range of 0.1%-0.5%, the carbon dioxide concentration within a range of 1%-5%, the nitrogen concentration within a range of 94.5%-98.9%, the temperature within a range of 15-25°C, and the humidity within a range of 55-65%.
[0033] Setting the oxygen concentration to the extremely low range of 0.1%-0.5% can strongly inhibit the oxidation reaction from the source of the chemical reaction (the concentration of reactants), so that the quality of the tobacco leaves that have been properly aged almost stops changing, thus effectively preventing "over-aging" and solving the core problem of long-term storage.
[0034] Setting the carbon dioxide concentration at 1%-5% helps suppress respiration while avoiding the potential negative impacts of excessively high concentrations on tobacco quality (such as sourness). Combined with a high-purity nitrogen background of 94.5%-98.9%, this creates a stable, inert, and mold-resistant high-quality gaseous environment.
[0035] Setting the temperature and humidity ranges to 15°C-25°C and 55%-65% respectively is the optimal range for maintaining the stable physical properties of tobacco leaves. In conjunction with a low-oxygen controlled environment, it can simultaneously inhibit biochemical reactions and physical deterioration (such as brittleness or mold), achieving comprehensive "dormant" preservation.
[0036] The adjustment parameters include preset gas types, target concentrations, target temperature values, and target humidity values based on the tobacco leaf information. These gas types, target concentrations, target temperature values, and target humidity values are all pre-stored by the user in corresponding tables. Finding the acquired tobacco leaf information will retrieve the corresponding gas types, target concentrations, target temperature values, and target humidity values.
[0037] By pre-storing independent "gas-temperature and humidity" target parameters for different tobacco leaf types (such as Yunnan flue-cured tobacco, Zimbabwean tobacco, Burley tobacco, etc.), the system can automatically match the best preservation solution, solving the industry pain point that different raw materials require different processes and greatly expanding the universality of the process.
[0038] Operators do not need to memorize or manually input complex parameters. They only need to select or scan the tobacco leaf type, and the system will automatically call up the complete set of settings, reducing human error, simplifying the operation process, and enabling the standardized execution of high-precision processes.
[0039] In one embodiment, the information on the tobacco leaves to be preserved, the gas information in the sealed tunnel, the temperature information, and the humidity information are respectively obtained by the user inputting or scanning barcodes or QR codes, oxygen concentration sensors, carbon dioxide concentration sensors, nitrogen concentration sensors, temperature sensors, and humidity sensors.
[0040] Real-time data collection using high-precision oxygen, carbon dioxide, nitrogen, temperature, and humidity sensors provides accurate and timely field data for the control algorithm, forming the foundation for achieving high-precision closed-loop control.
[0041] By combining user input, barcode or QR code scanning to obtain tobacco leaf information, the amount of manual data entry is greatly reduced, and information such as batch and origin of tobacco leaves can be quickly and accurately linked, providing a data entry point for realizing full-process digital management and quality traceability.
[0042] In one embodiment, the actuator includes an intake valve and an exhaust valve communicating with the sealed tunnel, and also includes a humidity regulator and an air conditioner disposed within the sealed tunnel.
[0043] By controlling the intake and exhaust valves, inert gases such as nitrogen can be precisely injected into the tunnel, while excess oxygen or carbon dioxide can be discharged, thereby actively and quickly adjusting the gas ratio to the target range.
[0044] The inclusion of humidity regulators (such as humidifiers / dehumidifiers) and air conditioners allows the system to independently and precisely control temperature and humidity. They work in conjunction with the gas control system to create and maintain a stable, complex environment where all parameters are under control.
[0045] In one embodiment, the adjustment algorithm calculates the flow rate of each gas using the following formula:
[0046] in, The flow rate of oxygen or carbon dioxide; , , For PID parameters; This refers to the gas content value detected by the corresponding sensor for oxygen or carbon dioxide. These are the corresponding adjustment parameter values for oxygen or carbon dioxide.
[0047] Specifically, the flow rate of oxygen or carbon dioxide is the flow rate in the exhaust pipe within the sealed tunnel. Excess oxygen and carbon dioxide produced by tobacco are expelled by injecting nitrogen into the sealed tunnel. Changing the flow rate of oxygen or carbon dioxide requires changing the rate at which nitrogen is injected into the sealed tunnel. The adjustment algorithm obtains... Subsequently, flow rate sensors for detecting oxygen and carbon dioxide are installed in the exhaust pipe to obtain real-time oxygen and carbon dioxide flow rates. Based on the real-time flow rates and... After comparison, adjust (increase or decrease) the rate of nitrogen injection into the sealed tunnel to make the real-time flow rates of oxygen and carbon dioxide approach each other. .
[0048] By employing a PID (proportional-integral-derivative) control algorithm, the system can not only react to the deviation between the current gas content and the target (proportional term), but also accumulate and eliminate historical deviations (integral term) and predict the trend of change (derivative term), thereby achieving fast, accurate and stable control without steady-state error.
[0049] This algorithm enables the system to respond quickly and smoothly to external disturbances (such as air entering due to the opening of the tunnel door), automatically adjusting it back to the set range, significantly improving the robustness (stability) of the entire preservation environment.
[0050] In one embodiment, establish , , The value of [value] is related to the tobacco leaf type, gas content, humidity, and temperature; the appropriate value should be selected based on the specific circumstances. , , value.
[0051] By establishing PID parameters ( , , By mapping the relationship between oxygen concentration and tobacco leaf type, real-time gas content, temperature, and humidity, the system can dynamically select the optimal control intensity based on the current operating conditions. For example, when the oxygen concentration is severely exceeded, it automatically adopts more aggressive control parameters, while using gentler parameters when the concentration is stable, thus achieving an optimal balance between control effectiveness and energy consumption and equipment wear.
[0052] This mapping relationship allows the same set of control algorithms to adapt more precisely to the physiological characteristics (such as breathing intensity) of different tobacco leaves and different environmental stages, which is a deeper manifestation of the "flexible and configurable" concept at the control execution level.
[0053] Specifically, the type of tobacco leaves determines the base value of the PID parameters, while real-time gas content, temperature, and humidity serve as correction factors to dynamically fine-tune the base values in order to achieve true adaptive flexible control.
[0054] The basic parameters are shown in Table 1 below (with "target oxygen concentration" as the main variable). Table 1 establishes the control baseline for different tobacco leaves under standard conditions.
[0055] Table 1
[0056] Table 2 below shows the environmental correction factor table. Table 2 defines how to dynamically adjust the base parameters based on real-time environmental deviations from standard conditions (e.g., standard temperature 20°C, humidity 60%).
[0057] Table 2
[0058] Query basic parameters: First, based on the tobacco leaf type and the set target oxygen concentration, refer to Table 1 above to obtain a set of initial (K) parameters. pbase ,K ibase ,K dbase ).
[0059] Real-time readings of current temperature, humidity, and oxygen concentration deviations are performed. For each environmental variable, the corresponding correction factor (C) is calculated according to Table 2. Kp C Ki C Kd ).
[0060] For example, if the current temperature is too high, a set of correction coefficients is obtained from the temperature row; if the humidity is too low, another set of coefficients is obtained from the humidity row.
[0061] The correction coefficients of each variable are combined by weighting or multiplying to obtain the final PID parameters applied to the current control cycle.
[0062] Final Kp = base K p ×C Kp (Temperature) × CKp (Humidity) × C Kp (O2 concentration deviation); K i and K d The calculation and K p same.
[0063] The control algorithm uses this set of dynamic parameters to perform PID calculations and outputs a control quantity. It can also record the control effect under different parameter combinations to optimize the correction coefficient table and achieve limited self-learning.
[0064] For scenarios where the direct control objective is to maintain carbon dioxide (CO2) concentration between 1% and 5%, the following basic parameter table (as shown in Table 3 below) and environmental correction factor table (as shown in Table 4 below) are constructed in accordance with engineering logic.
[0065] As shown in Table 3 below, the control tone is established based primarily on the respiration intensity of tobacco leaves (i.e., CO2 production rate).
[0066] Table 3
[0067] Table 4 below defines how to dynamically fine-tune the basic parameters based on the real-time environment. Standard conditions can be set as follows: temperature 20°C, humidity 60%, and CO2 concentration within the target range.
[0068] Table 4
[0069] Note: In Table 4, "↑" indicates increase or rise; "↓" indicates decrease or weaken; and "→" indicates approach.
[0070] CO2 control is inverse and intermittent (acting only when the limit is exceeded), so the algorithm must integrate anti-saturation mechanisms such as integral separation or integral limiting, which is a key difference from continuously adjusted O2 control.
[0071] Dual-mode control logic: Mode A (default): Suppression mode. When the measured CO2 value approaches or exceeds the target upper limit, PID closed-loop control is activated to actively de-suppress the CO2.
[0072] Mode B: Hold Mode. When the measured CO2 value is below the target lower limit, the PID output is forced to zero, and the deactivation device is completely shut down. This explicit "on / off" characteristic is an important component of CO2 control.
[0073] Coupling with O2 control: It should be noted that when a large amount of nitrogen is injected to reduce O2, CO2 will be diluted simultaneously. Therefore, at the algorithm level, after a large nitrogen injection event, the CO2 controller can temporarily reduce Kp or pause its operation to avoid over-adjustment.
[0074] Table 5 below defines two deviation states: severely too high and severely too low.
[0075] Table 5
[0076] In one embodiment, such as Figure 3 As shown, another aspect provides a modified atmosphere packaging system for sealing tobacco leaves, comprising: Sealed tunnels are used to hold tobacco leaves that need to be preserved. Data acquisition module 1 is installed inside the sealed tunnel; Processing module 2, data acquisition module 1 and processing module 2 are electrically connected; Execution module 3 is electrically connected to processing module 2.
[0077] The system is divided into three core modules: data acquisition, processing, and execution, clearly defining the functions and connections between each module. This modular design reduces system complexity and facilitates segmented debugging, maintenance, and upgrades.
[0078] This architecture fully covers the three core components of industrial automatic control: sensors (acquisition modules) perceive the environment, controllers (processing modules) calculate and make decisions, and valves and regulators (execution modules) change the environment through actions, forming a complete, automatically operating intelligent preservation system.
[0079] In one embodiment, the processing module is a PLC controller, and the adjustment algorithm is built into the processing module.
[0080] The PLC (Programmable Logic Controller) is used as the processing module. It is designed for industrial environments and features strong anti-interference ability, stable operation and low failure rate. It can meet the stringent requirements of continuous operation of tobacco warehouses year-round.
[0081] PLC programming languages are intuitive and have short development cycles. Built-in adjustment algorithms allow engineers to optimize and iterate the control logic based on practical debugging experience without affecting hardware connections, thus improving system maintainability.
[0082] In one embodiment, an alarm module 4 is also included, which is electrically connected to the processing module 2.
[0083] When sensor data is abnormal (such as oxygen concentration failing to decrease), equipment malfunctions (such as valve jamming), or environmental parameters are severely exceeded, the alarm module can immediately alert management personnel through sound, light, and electrical signals, preventing the entire batch of tobacco leaves from spoiling due to system failure and reducing storage risks.
[0084] Alarm logs can record historical data of system anomalies, helping technicians analyze failure modes, perform equipment maintenance in advance, shift from "reactive maintenance" to "preventive maintenance," and improve the overall availability of the system.
[0085] Specifically, alarm module 4 is an existing alarm.
[0086] In one embodiment, it further includes a human-computer interaction interface 5, which is electrically connected to the processing module 2.
[0087] Through the human-machine interface (HMI), operators can start and stop the process, set parameters, and switch tobacco leaf types with one click. They can also monitor all environmental parameters and system status in real time in the form of curves and numbers, making the complex control process intuitive and easy to manage.
[0088] HMI can automatically record and store process data throughout the entire lifecycle (temperature and humidity, gas concentration curves, alarm events, etc.), establishing a complete "preservation file" for each batch of stored tobacco leaves, and meeting the data needs for quality auditing and process optimization.
[0089] Specifically, the human-computer interaction interface 5 is the existing display touch screen.
[0090] Specifically, such as Figure 2 The diagram shows the nitrogen source acquisition process for the sealed tunnel. The gas outlet of the sealed tunnel passes through an electric ball valve, a vacuum pump, an electric ball valve, a gas storage tank, and a vacuum pump in sequence before entering the air inlet of the air compressor. The gas outlet of the air compressor passes through a gas storage tank, a dryer, a nitrogen generator, an electric ball valve, a vacuum pump, and an electric ball valve in sequence before entering the sealed tunnel, completing the nitrogen circulation and replenishment. This reduces the amount of nitrogen that the air compressor needs to generate from the air, improves nitrogen generation efficiency, and reduces the workload of the nitrogen generator.
[0091] The air compressor, all vacuum pumps, all electric ball valves, and nitrogen generator are all electrically connected to the processing module (PLC). An online oxygen analyzer is also connected to the outlet pipeline of the sealed tunnel to analyze the oxygen content in the pipeline and thus obtain the oxygen content in the sealed tunnel.
[0092] Specifically, such as Figure 4 The diagram shows the architecture of the adjustment algorithm. The specific workflow of each module working together is as follows: 1. Parameter initialization module; Function: This is the starting point of the algorithm, responsible for loading the "recipe" of the control target. When the operator selects the tobacco leaf type (such as "Yunnan flue-cured tobacco") through the human-machine interface (HMI), this module calls the corresponding target setpoints (such as O2: 0.3%, CO2: 3%, temperature: 20°C, humidity: 60%) and the corresponding initial control parameters (such as PID parameter groups) from the pre-stored parameter mapping table.
[0093] Significance: It realizes the emphasized "flexible configurability" and provides personalized execution basis for the entire control system.
[0094] 2. Real-time monitoring module; Function: As the "sensors" of the system, it collects real-time environmental data at a fixed frequency (e.g., every 5 seconds) by deploying gas sensors (O2, CO2), temperature and humidity sensors, etc. in sealed tunnels.
[0095] Significance: Converting physical environment (gas content, temperature and humidity) into data signals that can be processed by algorithms is the foundation of closed-loop control.
[0096] 3. Data processing center; Function: As the "nerve center" of the system, it receives raw data from the monitoring modules and performs processing such as filtering, cleaning, data fusion, and format standardization. For example, it averages data from multiple similar sensors to improve reliability, or packages the data into a standard format and distributes it to multiple downstream modules such as decision-making, adaptive, and alarm systems.
[0097] Significance: It ensures that the data received by downstream modules is accurate, reliable, and consistent, thereby improving the decision-making quality of the entire system.
[0098] 4. Control Decision Module; Function: This is the "brain" of the algorithm. It receives the processed data, compares it with the target value set by the "parameter initialization module," and calculates the deviation. Then, it uses the previously defined PID control algorithm (or other advanced algorithms, such as fuzzy logic or model predictive control) to calculate the control quantity (such as the opening degree of the nitrogen valve or the power of the air conditioner) required to eliminate the deviation.
[0099] Significance: Transforming simple monitoring data into specific, quantifiable execution instructions is the core computational step in achieving precise control.
[0100] 5. Execution control module; Function: As the "hands and feet" of the system, it receives instructions from the decision-making module, converts them into specific and safe electrical signals or communication protocols, and drives the actuators (such as intake valves, exhaust valves, solenoid valves, frequency converters, and air conditioning compressors) to perform precise actions.
[0101] Significance: It completes the final conversion from "digital instructions" to "physical actions", directly changing the gas and physical environment within the tunnel.
[0102] 6. Adaptive module; Function: Serves as the system's "learner and optimizer." It continuously observes the control effect (such as overshoot and settling time) and, based on historical data and preset rules, fine-tunes key parameters (such as PID parameters) in the control decision module online. For example, if a slow response is detected in the early stages of system operation, the proportional gain Kp can be automatically increased.
[0103] Significance: It endows the system with preliminary intelligence and self-optimization capabilities, enabling the control process to become better with adjustments and dynamically adapt to changes in the state of tobacco leaves and the environment.
[0104] 7. Alarm and Log Module; Function: Serving as the system's "safety sentinel and archivist." It monitors all data streams and immediately triggers multi-level alarms upon detecting anomalies (such as sensor malfunction, severely excessive concentration, or equipment communication interruption). Simultaneously, it continuously records all sensor data, control commands, and alarm events, forming a complete operational log.
[0105] Significance: It ensures the security and traceability of system operation, and provides an immutable data foundation for fault diagnosis, process auditing and subsequent optimization.
[0106] This architecture is clearly designed and highly modular, comprehensively covering all key aspects of modern industrial control. It not only achieves basic closed-loop control, but also, through the hub design of the data processing center and the introduction of adaptive modules, realizes centralized information processing and intelligent optimization, demonstrating the evolution from "automation" to "intelligence."
[0107] The above are merely optional embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application. Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.
Claims
1. A modified atmosphere packaging process for sealing tobacco leaves, characterized in that, Includes the following steps: S1. Obtain information on the tobacco leaves to be preserved, the gas information, temperature information, and humidity information in the sealed tunnel; S2. Obtain the adjustment parameters based on the information obtained in step S1; S3. Based on the adjustment parameters and the adjustment algorithm, obtain execution data for adjusting the gas type and corresponding content value in the sealed tunnel, and the temperature and humidity in the tunnel within the set range; S4. Based on the execution data, the execution mechanism performs the corresponding action.
2. The preservation process according to claim 1, characterized in that, Among the adjustment parameters, the gas types include nitrogen, oxygen, and carbon dioxide; the oxygen concentration is set within the range of 0.1%-0.5%, the carbon dioxide concentration within the range of 1%-5%, the nitrogen concentration within the range of 94.5%-98.9%, the temperature within the range of 15-25°C, and the humidity within the range of 55-65%.
3. The preservation process according to claim 2, characterized in that, The information on the tobacco leaves to be preserved, the gas information in the sealed tunnel, the temperature information, and the humidity information are respectively obtained by the user through input, scanning of barcodes or QR codes, and by oxygen concentration sensors, carbon dioxide concentration sensors, nitrogen concentration sensors, temperature sensors, and humidity sensors.
4. The preservation process according to claim 3, characterized in that, The actuator includes an intake valve and an exhaust valve communicating with the sealed tunnel, and also includes a humidity regulator and an air conditioner disposed within the sealed tunnel.
5. The preservation process according to claim 4, characterized in that, The adjustment algorithm calculates the flow rate of each gas using the following formula: in, The flow rate of oxygen or carbon dioxide; , , For PID parameters; This refers to the gas content value detected by the corresponding sensor for oxygen or carbon dioxide. The value of the adjustment parameter corresponding to oxygen or carbon dioxide.
6. The preservation process according to claim 5, characterized in that, Establish , , The value of [value] is related to the tobacco leaf type, gas content, humidity, and temperature; the appropriate value should be selected based on the specific circumstances. , , value.
7. A controlled atmosphere preservation system for sealed tobacco leaves, characterized in that, For performing the preservation process as described in claim 6, comprising: A sealed tunnel for containing tobacco leaves to be preserved; A data acquisition module is installed inside the sealed tunnel. The data acquisition module is electrically connected to the processing module. An execution module is electrically connected to the processing module.
8. The preservation system according to claim 7, characterized in that, The processing module is a PLC controller, and the adjustment algorithm is built into the processing module.
9. The preservation system according to claim 7, characterized in that, It also includes an alarm module, which is electrically connected to the processing module.
10. The preservation system according to claim 7, characterized in that, It also includes a human-computer interaction interface, which is electrically connected to the processing module.