A ship ventilation volume regulation and monitoring system and method

Abstract

This invention belongs to the field of ship ventilation control technology, and in particular to a ship ventilation airflow regulation and monitoring system and method, comprising: a standard database construction module, used to pre-establish and store standard airflow demand values ​​corresponding to multiple ship operating conditions, wherein the standard airflow demand values ​​are determined according to ship design parameters and / or historical operating data, and each operating condition corresponds to a standard airflow demand value; a real-time data acquisition module, used to collect the actual airflow value in the ship's ventilation ducts in real time at a set sampling period; and a difference calculation module, used to retrieve the corresponding standard airflow demand value from the standard database construction module according to the current ship operating condition; a standard airflow demand database covering multiple operating conditions is established, giving ventilation control a dynamic and multi-dimensional reference basis, avoiding the problem of excessive or insufficient airflow caused by fixed preset values.

Description

Technical Field

[0001] This invention belongs to the field of ship ventilation control technology, specifically relating to a ship ventilation volume regulation and monitoring system and method. Background Technology

[0002] Ship ventilation systems are crucial for ensuring ship safety, crew comfort, and the normal operation of equipment. Their core function is to provide adequate fresh air to areas such as the engine room, cargo holds, and living quarters to control temperature, humidity, concentration of harmful gases, and dust levels. Especially in large ships or special vessel types (such as liquefied gas carriers and ro-ro passenger ships), precise airflow control directly impacts energy efficiency and fire and explosion safety.

[0003] Currently, the regulation and monitoring of ship ventilation volume mainly rely on the following existing technologies: First, independent PID control based on preset values. Most ship ventilation systems use a local or central control room proportional-integral-derivative (PID) controller. Operators set a fixed target airflow value based on experience or design manuals. The system receives real-time feedback from airflow sensors, and the controller adjusts dampers or frequency converters to approach the set value.

[0004] Second, alarm mechanisms based on simple thresholds. Existing monitoring systems typically only set high and low thresholds for a single physical quantity (such as fan current, duct static pressure, and cabin temperature). When the monitored value exceeds the threshold range, an audible and visual alarm is triggered. The alarm logic mostly compares the "real-time measured value" with "fixed upper and lower limits".

[0005] Third, discrete database applications. Some advanced systems record historical operational data (such as air volume, energy consumption, and environmental parameters) to form log databases for post-event queries or trend analysis. However, these databases are mostly for passive storage and lack active interaction with the real-time control closed loop.

[0006] However, as ships increasingly demand intelligent energy efficiency management (such as EEDI and EEXI requirements) and adaptability to complex operating conditions, the aforementioned existing technologies and systems have revealed significant shortcomings in practical applications.

[0007] First, there is a lack of a dynamic, multi-dimensional standard reference system. In actual ship operation, the required air volume changes dynamically with the ship's operating conditions (navigation, loading and unloading, berthing), environmental conditions (seawater temperature, atmospheric pressure), changes in compartment usage (personnel density, cargo-released gases), and equipment status (main engine load). Existing technologies use fixed preset values ​​or single threshold alarms, failing to establish a theoretically optimal air volume standard database that covers multiple operating conditions. This results in either excessive ventilation leading to huge energy consumption or insufficient ventilation causing safety hazards.

[0008] Secondly, the real-time monitoring and alarm logic is simplistic and unable to identify systemic deviations. Existing alarms only address instantaneous sensor values ​​exceeding limits, lacking the ability to dynamically compare real-time monitored airflow with theoretical airflow under corresponding operating conditions in a standard database. When the system experiences malfunctions such as duct blockage, filter contamination, or fan performance degradation, the actual airflow gradually deviates from the theoretical required value, but this may not trigger a simple fixed threshold alarm, leading to potential faults being overlooked for a long time.

[0009] Furthermore, there is a lack of proactive early warning mechanisms based on discrepancies. Existing technologies cannot issue warnings to administrators in the early stages of system performance degradation; alarms are only triggered when discrepancies accumulate to a fixed threshold, often missing the optimal maintenance window.

[0010] To address the aforementioned issues, this application proposes a ship ventilation volume regulation and monitoring system and method thereof. Summary of the Invention

[0011] To address the problems mentioned in the background section, this invention provides a ship ventilation volume regulation and monitoring system and method, which solves the technical problems of existing technologies such as the lack of a dynamic standard reference system, the inability to identify systematic deviations due to simplistic alarm logic, and the lack of a proactive early warning mechanism based on differences.

[0012] To achieve the above objectives, the present invention provides the following technical solution: a ship ventilation volume regulation and monitoring system, comprising: The standard database construction module is used to pre-establish and store standard air volume requirements for multiple ship operating conditions. The standard air volume requirements are determined based on ship design parameters and / or historical operating data, with one standard air volume requirement for each operating condition.

[0013] The real-time data acquisition module is used to collect the actual air volume value inside the ship's ventilation duct in real time at a set sampling period.

[0014] The difference calculation module is used to retrieve the corresponding standard air volume requirement value from the standard database construction module according to the current ship operating conditions, compare the actual air volume value with the standard air volume requirement value, and calculate the air volume difference value and relative deviation rate between the two. The relative deviation rate is calculated according to the following formula: Relative deviation rate = |actual air volume value - standard air volume requirement value| / standard air volume requirement value × 100%.

[0015] The alarm determination module is used to determine whether the relative deviation rate exceeds a preset allowable deviation rate threshold. If it does, an alarm signal is generated and sent to the human-machine interface or centralized alarm unit of the ship monitoring system.

[0016] Furthermore, the real-time data acquisition module also includes a filtering unit, which is used to perform arithmetic averaging on multiple continuously acquired actual air volume values, and send the calculated arithmetic average as the valid actual air volume value at the current moment into the difference calculation module to eliminate the interference of instantaneous fluctuations on the air volume difference calculation results.

[0017] Furthermore, the standard database construction module stores at least the following ship operating conditions: ship navigation status (including navigation, berthing, loading and unloading), engine room load level, cabin personnel density level, external ambient temperature range, and cargo hold gas concentration level; the standard air volume requirement value is obtained by looking up a table, that is, matching the currently detected operating condition parameters in the standard database. If a completely identical operating condition is matched, the corresponding standard air volume value is directly read; if no completely identical operating condition is matched, the standard air volume value corresponding to the closest operating condition is selected as the reference value.

[0018] Furthermore, the alarm determination module is configured with a multi-level alarm mode, including a first alarm unit and a second alarm unit. The first alarm unit generates a level-one warning signal when the relative deviation rate is greater than or equal to a first allowable threshold but less than a second allowable threshold; the second alarm unit generates a level-two severe alarm signal when the relative deviation rate is greater than or equal to the second allowable threshold. The first allowable threshold is less than the second allowable threshold, and the specific value is set according to the ship's ventilation safety requirements.

[0019] Furthermore, the system also includes an alarm delay confirmation module, which confirms the issuance of an alarm signal of that level only after the relative deviation rate has continuously exceeded the corresponding threshold for a preset delay time; if the relative deviation rate falls back below the threshold within the delay time, the current alarm triggering process is terminated to avoid frequent false alarms caused by instantaneous fluctuations in air volume.

[0020] Furthermore, the system also includes an automatic airflow adjustment module. This module calculates the adjustment amount based on the airflow difference value output by the difference calculation module, using a proportional control algorithm or a proportional-integral control algorithm. Specifically, the adjustment amount = proportional coefficient × airflow difference value, or the adjustment amount = proportional coefficient × airflow difference value + integral coefficient × historical cumulative sum of airflow difference values. This adjustment amount is output as a control command to the fan frequency converter or electric damper actuator of the ship's ventilation system to change the fan speed or damper opening, thereby bringing the actual airflow value closer to the standard airflow demand value.

[0021] Furthermore, the system also includes a database self-learning and updating module. This module is used to periodically record the operating parameters and corresponding actual airflow values ​​during periods when the actual airflow value is stable and no alarms are triggered, either during system operation or when set conditions are met. It also corrects the corresponding standard airflow demand values ​​in the standard database module. The correction method involves weighting the original standard airflow demand value and the currently recorded stable actual airflow value according to a certain weight, obtaining an updated standard airflow demand value, and storing it in the database. This allows the standard database to adapt to airflow demand deviations caused by aging ship equipment or environmental changes.

[0022] This invention also provides a method for monitoring and regulating ship ventilation volume, comprising the following steps: Step S1: Pre-establish and store standard air volume requirements for multiple ship operating conditions to form a standard database.

[0023] Step S2: Collect the actual air volume value in the ship's ventilation duct in real time at the set sampling period.

[0024] Step S3: Based on the current ship operating conditions, retrieve the corresponding standard air volume demand value from the standard database, and calculate the air volume difference and relative deviation rate between the actual air volume value and the standard air volume demand value.

[0025] Step S4: Determine whether the relative deviation rate exceeds the preset allowable deviation rate threshold. If it does, generate an alarm signal.

[0026] Furthermore, in step S2, before calculating the air volume difference value, the arithmetic average of multiple continuously collected actual air volume values ​​is first processed, and the average value obtained is used as the current actual air volume value for subsequent calculations.

[0027] Furthermore, step S4 employs a multi-level threshold judgment method: no alarm is triggered when the relative deviation rate is less than the first threshold; a first-level warning is issued when the relative deviation rate is greater than or equal to the first threshold and less than the second threshold; and a second-level severe alarm is issued when the relative deviation rate is greater than or equal to the second threshold. Moreover, an alarm signal is only actually output after the relative deviation rate has continuously exceeded the corresponding threshold for a preset delay.

[0028] Furthermore, the method also includes step S5: based on the air volume difference value, a proportional control algorithm or a proportional-integral control algorithm is used to calculate the control quantity, and the result is output to the fan frequency converter or damper actuator to adjust the fan speed or damper opening so that the actual air volume value approaches the standard air volume demand value, thereby achieving automatic correction before the alarm is triggered.

[0029] Compared with the prior art, the beneficial effects of the present invention are: A standard air volume demand database covering multiple operating conditions has been established, providing a dynamic and multi-dimensional reference for ventilation control and avoiding the problem of excessive or insufficient air volume caused by fixed preset values.

[0030] It enables dynamic comparison of actual air volume with standard air volume, and can identify systematic deviations caused by equipment aging, filter blockage, etc., making up for the shortcomings of traditional simple threshold alarms.

[0031] A multi-level alarm and delayed confirmation mechanism has been introduced, which can issue early warning prompts for maintenance when the deviation is small, and avoid false alarms caused by instantaneous fluctuations.

[0032] Optionally, it integrates automatic adjustment and self-learning update functions, forming a closed-loop intelligent ventilation management system of "monitoring-comparison-alarm-adjustment-learning", which effectively improves the safety, energy efficiency and intelligence level of the ship's ventilation system. Attached Figure Description

[0033] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a block diagram of the overall structure of the ship ventilation volume regulation and monitoring system in an embodiment of the present invention.

[0034] Figure 2 This is a flowchart of the ship ventilation volume regulation and monitoring method in an embodiment of the present invention.

[0035] 1. Standard database construction module; 2. Real-time data acquisition module; 21. Filtering unit; 3. Difference calculation module; 4. Alarm judgment module; 41. First alarm unit; 42. Second alarm unit; 5. Alarm delay confirmation module; 6. Automatic airflow adjustment module; 7. Database self-learning and updating module. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0037] like Figure 1 As shown in the figure, this embodiment provides a ship ventilation air volume adjustment and monitoring system. The system includes a standard database construction module 1, a real-time data acquisition module 2, a difference calculation module 3, an alarm judgment module 4, an alarm delay confirmation module 5, and an automatic air volume adjustment module 6.

[0038] The standard database construction module 1 is used to pre-establish and store standard airflow requirements for multiple ship operating conditions. In practical implementation, designers first determine the theoretical airflow requirements of the ship under different operating conditions based on the ship's design drawings, ventilation calculations, and historical operating data. For example, for engine room ventilation, the following operating conditions and corresponding standard airflows can be set: 20,000 m³ / h for navigation conditions (main engine load above 85%); 8,000 m³ / h for berthing conditions (main engine off, auxiliary engines running); and 15,000 m³ / h for loading / unloading conditions (increased cargo hold ventilation requirements). The standard database can be stored using a relational database or a simple configuration file and deployed in the ship's control room monitoring computer or a dedicated embedded controller.

[0039] The real-time data acquisition module 2 connects to a wind speed sensor or airflow measurement device installed in the ventilation duct, and collects actual airflow values ​​at a set sampling period (e.g., 1 second). The real-time data acquisition module 2 also includes a filtering unit 21, which performs an arithmetic average on the five consecutively collected actual airflow values. For example, if the five most recently collected values ​​are 19800, 20200, 19900, 20100, and 20000, the average value is (19800 + 20200 + 19900 + 20100 + 20000) / 5 = 20000 m³ / h. This average value is then sent to the difference calculation module 3 as the current valid actual airflow value. Using an arithmetic average filter effectively eliminates measurement noise caused by transient sensor fluctuations or fluid disturbances.

[0040] The difference calculation module 3 first retrieves the corresponding standard airflow requirement value from the standard database construction module 1 based on the current ship operating conditions (e.g., navigation status obtained through the Automatic Identification System, main engine load level obtained through the engine room monitoring and alarm system). Assuming the current operating condition is navigation, the standard airflow requirement is 20,000 m³ / h, and the actual average airflow is 19,000 m³ / h. The difference calculation module 3 calculates the airflow difference value ΔQ = 19,000 - 20,000 = -1,000 m³ / h, and calculates the relative deviation rate δ = |19,000 - 20,000| / 20,000 × 100% = 5%.

[0041] The alarm judgment module 4 presets a first allowable threshold (e.g., 5%) and a second allowable threshold (e.g., 15%). When δ=5%, the first allowable threshold is reached but the second allowable threshold is not reached. The first alarm unit 41 generates a level one warning signal, which can be sent to the central control room monitoring interface, prompting the operator with a flashing yellow icon that "the ventilation volume is too low, it is recommended to check the filter or air duct." If the actual air volume continues to drop to 17000 m³ / h, then δ=15%, reaching the second allowable threshold. The second alarm unit 42 generates a level two severe alarm signal, which flashes red and is accompanied by an audible alarm, prompting "the ventilation volume is seriously insufficient, please stop the machine immediately for inspection."

[0042] The alarm delay confirmation module 5 is located after the alarm judgment module 4. Its function is to prevent false alarms caused by momentary interference. For example, the delay time is set to 5 seconds. If the actual air volume recovers to below the threshold within 5 seconds, the alarm will not be issued; only when the relative deviation rate continuously exceeds the corresponding threshold for 5 seconds will the alarm be confirmed and issued. In this way, when the ship experiences a brief fluctuation in air volume due to the instantaneous opening and closing of hatches, unnecessary alarms will not be triggered.

[0043] The automatic airflow adjustment module 6 receives the airflow difference value ΔQ = -1000 m³ / h output by the difference calculation module 3 and calculates the adjustment amount using a proportional-integral control algorithm. Let the proportional coefficient Kp = 0.5, the integral coefficient Ki = 0.05, and the control period Ts = 2 seconds. The proportional term is 0.5 × (-1000) = -500, and the integral term accumulates historical deviations. Assuming the initial integral term is 0, the first adjustment amount u = -500 (corresponding to a 50 rpm reduction in the frequency converter) is output to the fan frequency converter, appropriately reducing the fan speed to decrease unnecessary energy consumption (when the actual airflow is higher than the standard) or increasing the speed (when the actual airflow is lower than the standard). Through multiple adjustments, the actual airflow gradually approaches the standard airflow requirement value. Of course, this embodiment can also use simple proportional control, i.e., adjustment amount = proportional coefficient × airflow difference value, to reduce system complexity. Example

[0044] This embodiment adds a database self-learning update module 7 to the existing embodiment 1, while the other modules are the same as those in embodiment 1.

[0045] During system operation, the database self-learning update module 7 records the average actual airflow value of the past hour and the operating parameters for that period at 2:00 AM daily (when the ship is typically operating at a low load and stable speed). Assuming that over five consecutive days of stable operation, the actual airflow value under navigation conditions is consistently recorded at around 19,500 m³ / h, while the standard airflow requirement stored in the standard database is 20,000 m³ / h, this could be due to slight filter clogging or fan impeller wear leading to decreased system efficiency. The self-learning update module 7 corrects the standard value using the following weighted average formula: Updated standard air volume = α × original standard air volume + (1-α) × average actual air volume Taking α = 0.8 (meaning retaining 80% of the original design value and adopting 20% ​​of the actual empirical value), the new standard air volume = 0.8 × 20000 + 0.2 × 19500 = 16000 + 3900 = 19900 m³ / h. The corrected standard value is stored in the database. After multiple learning cycles, the standard database will better reflect the current actual characteristics of the ship, avoiding continuous deviation alarms due to equipment aging. Example

[0046] This embodiment provides a method for monitoring and regulating ship ventilation volume using the above-described system, such as... Figure 2 As shown, it includes the following steps: Step S1: Pre-establish and store standard air volume requirements for multiple ship operating conditions to form a standard database. In practice, the theoretical air volume values ​​from the ventilation calculation sheets provided by the ship designer can be entered into the database and stored according to operating conditions.

[0047] Step S2: Collect the actual air volume value inside the ship's ventilation duct in real time at a set sampling period (e.g., 1 second), and perform an arithmetic average on multiple continuously collected actual air volume values ​​to obtain a filtered actual air volume value. In this embodiment, N=5, that is, an averaged actual air volume value is output every 5 seconds.

[0048] Step S3: Based on the current ship operating conditions, retrieve the corresponding standard air volume requirement value from the standard database, and calculate the air volume difference and relative deviation rate between the actual air volume value and the standard air volume requirement value. For example, if the actual air volume value is 18000 m³ / h and the standard value is 20000 m³ / h, then the difference value is -2000 m³ / h, and the relative deviation rate is 10%.

[0049] Step S4: Determine whether the relative deviation rate exceeds the preset allowable deviation rate threshold. In this embodiment, the first threshold is set to 8%, and the second threshold is set to 20%. Since 10% > 8% and 10% < 20%, a level one warning is triggered. Simultaneously, before issuing the alarm, a delay confirmation is initiated: continuous monitoring for 5 seconds; if the relative deviation rate remains greater than or equal to 8% within 5 seconds, a level one warning signal is output to the human-machine interface at the 5th second; if the relative deviation rate drops below 8% during this period, the alarm is canceled.

[0050] Step S5: Based on the airflow difference, calculate the control quantity using a proportional control algorithm. Assuming a proportional coefficient Kp = 0.6, the control quantity = 0.6 × (-2000) = -1200, corresponding to a 120 rpm reduction in the fan inverter frequency (or a corresponding adjustment of the damper opening). After the output is executed, the actual airflow gradually recovers until the deviation is eliminated or reduced to an acceptable range.

[0051] Through the above steps, the method of the present invention realizes intelligent monitoring of the entire process of ship ventilation volume, including "standard database establishment - real-time monitoring - difference calculation - graded delay alarm - automatic adjustment".

[0052] This invention can be widely applied to ventilation systems in engine rooms, cargo holds, and living quarters of various civilian and military vessels, and is particularly suitable for remote monitoring and management of intelligent and unmanned ships. Through this invention, ship operators can effectively reduce energy consumption in ventilation systems, extend equipment lifespan, and improve ship operational safety, demonstrating promising prospects for industrial applications.

[0053] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A ship ventilation volume regulation and monitoring system, characterized in that, include: The standard database construction module is used to pre-establish and store standard air volume demand values ​​corresponding to multiple ship operating conditions. The standard air volume demand values ​​are determined based on ship design parameters and / or historical operating data, and each operating condition corresponds to a standard air volume demand value. The real-time data acquisition module is used to collect the actual air volume value inside the ship's ventilation duct in real time at a set sampling period; The difference calculation module is used to retrieve the corresponding standard air volume requirement value from the standard database construction module according to the current ship operating conditions, compare the actual air volume value with the standard air volume requirement value, and calculate the air volume difference value and relative deviation rate between the two. The relative deviation rate is calculated according to the following formula: Relative deviation rate = |Actual air volume value - Standard air volume requirement value| / Standard air volume requirement value × 100%; The alarm determination module is used to determine whether the relative deviation rate exceeds a preset allowable deviation rate threshold. If it does, an alarm signal is generated and sent to the human-machine interface or centralized alarm unit of the ship monitoring system.

2. The ship ventilation volume regulation and monitoring system according to claim 1, characterized in that, The real-time data acquisition module further includes a filtering unit, which is used to perform an arithmetic average on multiple continuously acquired actual air volume values. Specifically, the N most recently acquired actual air volume values ​​are added together and then divided by N. The calculated arithmetic average is then sent to the difference calculation module as the valid actual air volume value at the current moment, thereby eliminating the interference of instantaneous fluctuations on the air volume difference calculation result. Here, N is a preset number of samples, with a value range of 3 to 10.

3. The ship ventilation volume regulation and monitoring system according to claim 1, characterized in that, The standard database construction module stores ship operating conditions that include at least one or more of the following types: ship navigation status (including navigation, berthing, loading and unloading), engine room load level (including light load, medium load, heavy load), cabin personnel density level, external ambient temperature range, and cargo hold gas concentration level; the standard air volume requirement value is obtained by looking up a table, that is, matching the currently detected operating condition parameters in the standard database. If a completely identical operating condition is matched, the corresponding standard air volume value is directly read. If no completely identical operating condition is matched, the standard air volume value corresponding to the closest operating condition is selected as the reference value.

4. The ship ventilation volume regulation and monitoring system according to claim 1, characterized in that, The alarm determination module is further configured as a multi-level alarm mode, including a first alarm unit and a second alarm unit, wherein: the first alarm unit is used to generate a first-level early warning signal when the relative deviation rate is greater than or equal to a first allowable threshold but less than a second allowable threshold, prompting the operator to pay attention to the airflow deviation trend; the second alarm unit is used to generate a second-level severe alarm signal when the relative deviation rate is greater than or equal to the second allowable threshold, prompting the operator to immediately perform inspection or maintenance; the first allowable threshold is less than the second allowable threshold, and the specific values ​​of both are set according to the ship's ventilation safety requirements.

5. The ship ventilation volume regulation and monitoring system according to claim 4, characterized in that, It also includes an alarm delay confirmation module, which confirms the issuance of an alarm signal of that level only after the relative deviation rate has continuously exceeded the corresponding threshold for a preset delay time; if the relative deviation rate falls back below the threshold within the delay time, the current alarm triggering process is terminated, thereby avoiding frequent false alarms caused by instantaneous fluctuations in air volume.

6. The ship ventilation volume regulation and monitoring system according to claim 1, characterized in that, It also includes an automatic airflow adjustment module, which calculates the adjustment amount based on the airflow difference value output by the difference calculation module using a proportional control algorithm or a proportional-integral control algorithm. Specifically, the adjustment amount is calculated as: adjustment amount = proportional coefficient × airflow difference value, or the adjustment amount with an integral term = proportional coefficient × airflow difference value + integral coefficient × historical cumulative sum of airflow difference values. This adjustment amount is output to the fan frequency converter or electric damper actuator of the ship's ventilation system in the form of a control command to change the fan speed or damper opening, thereby making the actual airflow value approach the standard airflow demand value.

7. The ship ventilation volume regulation and monitoring system according to claim 1, characterized in that, It also includes a database self-learning update module. This self-learning update module is used to record the operating parameters and corresponding actual air volume values ​​during the period when the actual air volume value is stable and no alarm is triggered during system operation, periodically or when set conditions are met. It also corrects the corresponding standard air volume demand value in the standard database module. The correction method is to take a weighted average of the original standard air volume demand value and the stable actual air volume value recorded this time according to a certain weight, and then store the updated standard air volume demand value in the database. This allows the standard database to adapt to the air volume demand deviation caused by the aging of ship equipment or environmental changes.

8. A method for monitoring and regulating ship ventilation volume using the system described in any one of claims 1 to 7, characterized in that, Includes the following steps: Step S1: Pre-establish and store standard air volume requirements for multiple ship operating conditions to form a standard database; Step S2: Collect the actual air volume value in the ship's ventilation duct in real time at the set sampling period; Step S3: Based on the current ship operating conditions, retrieve the corresponding standard air volume demand value from the standard database, and calculate the air volume difference and relative deviation rate between the actual air volume value and the standard air volume demand value; Step S4: Determine whether the relative deviation rate exceeds the preset allowable deviation rate threshold. If it does, generate an alarm signal.

9. The method for regulating and monitoring ship ventilation volume according to claim 8, characterized in that, In step S2, before calculating the air volume difference value, the arithmetic mean of multiple continuously collected actual air volume values ​​is first processed, and the average value is used as the current actual air volume value for subsequent calculations. In step S4, a multi-level threshold judgment method is adopted. When the relative deviation rate is less than the first threshold, no alarm is triggered. When the relative deviation rate is greater than or equal to the first threshold and less than the second threshold, a first-level warning is issued. When the relative deviation rate is greater than or equal to the second threshold, a second-level severe alarm is issued. Furthermore, an alarm signal is only actually output after the relative deviation rate has continuously exceeded the corresponding threshold for a preset delay.

10. The method for regulating and monitoring ship ventilation volume according to claim 8, characterized in that, The method also includes step S5: based on the air volume difference value, a proportional control algorithm or a proportional-integral control algorithm is used to calculate the control quantity and output it to the fan frequency converter or damper actuator to adjust the fan speed or damper opening so that the actual air volume value is close to the standard air volume demand value, thereby achieving automatic correction before the alarm is triggered.

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