Automatic adjusting method for combustion type inert gas system for ship

Abstract

The invention provides an automatic adjusting method of a combustion type inert gas system for a ship, and belongs to the technical field of safety protection of a ship dangerous cargo tank, and the automatic adjusting method comprises the following steps: presetting reference parameters and threshold values such as inert gas yield, oxygen content, pressure and oil supply pressure; after the system is operated, data such as fan power, oxygen content, pressure and temperature are collected in real time and compared with preset values, and deviation is calculated. If the deviation exceeds the threshold value, the control device outputs an instruction to adjust the rotating speed of the fan, the oil supply unit, the air door, the adjusting valve and the cooling water pump in a linkage manner, so that parameters return to a normal range. The process is cyclically executed to form closed-loop control, and it is ensured that the safe inerting state in the liquid cargo tank is continuously maintained. Through a multi-parameter linkage closed-loop automatic adjustment and fault emergency mechanism, accurate and stable control over key indexes such as the oxygen content of inert gas is achieved, and it is guaranteed that the ship liquid cargo tank is in a high-safety inerting state all the time while manual dependence is greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of safety protection technology for dangerous liquid cargo tanks on ships, and more specifically, to an automatic adjustment method for a combustion-type inert gas system for ships. Background Technology

[0002] Marine combustion-type inert gas systems are core equipment for ensuring the safe navigation of dangerous liquid cargo ships. They generate low-oxygen flue gas through fuel combustion, which is then scrubbed and purified before being delivered to the cargo tanks to maintain an inert state with an oxygen content below 8% VOL, preventing combustion and explosion accidents. However, the operation and adjustment of existing systems mainly rely on manual experience or simple semi-automatic control, exhibiting significant lag and instability: manual operation struggles to respond in real-time to fluctuations in operating conditions, easily leading to excessive oxygen content or abnormal pressure. Furthermore, differences in operation among different crew members make it difficult for the system to maintain a precise and stable state over a long period, significantly increasing the workload and safety risks for crew members. Existing semi-automatic solutions are mostly limited to independent adjustment of a single parameter such as oxygen content or pressure, lacking a coordinated linkage mechanism between multiple parameters. This often results in a "one-sided" phenomenon, such as adjusting only the damper to control oxygen content while ignoring fuel supply pressure matching, leading to incomplete combustion, energy waste, and decreased inert gas quality, or causing pipeline oscillations and equipment damage due to a crude pressure regulation strategy.

[0003] Furthermore, existing technologies generally lack robust closed-loop feedback and emergency fault-tolerance mechanisms. When faced with sudden changes in sensor data, actuator failures, or interference from complex sea conditions, the system cannot automatically identify deviation thresholds and make precise compensation adjustments. This easily leads to over-adjustment or failure, forcing the system to frequently switch to manual mode or even shut down, seriously threatening the ship's continuous and safe supply capabilities during navigation and berthing. This current state of low adjustment accuracy, poor linkage, and insufficient safety is no longer sufficient to meet the stringent requirements of the China Classification Society (CCS) regulations for high reliability of inert gas systems and the stringent requirements of chemical transport ships for inert gas quality (oxygen content stable at 3%-4% VOL). There is an urgent need for an intelligent control method that can achieve fully automatic multi-parameter linkage adjustment, has fault emergency handling capabilities, and is highly adaptable, in order to fundamentally solve the technical bottlenecks of high dependence on manual operation, large system fluctuations, and prominent safety hazards. Summary of the Invention

[0004] The purpose of this invention is to provide an automatic adjustment method for a marine combustion-type inert gas system, which aims to solve the problems mentioned in the background art.

[0005] This invention is implemented as follows: an automatic adjustment method for a marine combustion-type inert gas system, applied to a marine combustion-type inert gas system including air supply equipment, inert gas generating equipment, cooling water supply equipment, fuel supply equipment, conveying and discharging equipment, monitoring equipment, and control devices, comprising the following steps: S1. The control device presets the inert gas production preset value, inert gas oxygen content preset value, pressure preset range, burner oil supply pressure preset range, deviation threshold and valve adjustment step value. S2. After the system is running, the monitoring device collects real-time data on fan power, inert gas oxygen content, pressure at key points of the system, inert gas temperature and equipment status, and sends the collected data to the control device. S3. The control device compares the real-time collected data with the preset benchmark parameters in step S1, calculates the deviation value, and determines whether the deviation value is greater than or equal to the preset deviation threshold. S4. When the parameters are determined to be abnormal, the control device outputs an adjustment command to control the fan speed, oil supply unit, burner damper, inert gas regulating valve, exhaust valve and cooling water pump in a coordinated manner, so that the parameters return to the preset range. S5. Repeat steps S2 to S4 to form a closed-loop regulation mechanism to maintain the inert state in the dangerous goods liquid cargo tanks of the ship.

[0006] Optionally, in step S2, the specific methods of data acquisition include: By monitoring the fan current and power, and comparing the fan's power-flow curve, the system automatically calculates the air supply flow and inert gas production. The oxygen content data of inert gas at the outlet of the inert gas generator is collected by an oxygen content sensor. Pressure sensors are used to collect the air supply pressure at the fan outlet, the inert gas generator outlet pressure, and the inert gas main pipe pressure.

[0007] Optionally, in step S3, the specific process of parameter comparison and deviation judgment is as follows: The flow rate, oxygen content, and pressure are compared sequentially, and then a deviation judgment is made. The flow rate comparison is to compare the real-time automatically calculated inert gas output with the preset inert gas output. The oxygen content comparison is to compare the real-time collected inert gas oxygen content data with the preset inert gas oxygen content value. The pressure comparison is to compare the real-time collected inert gas generator outlet pressure data with the preset pressure range. If the deviation value is less than the deviation threshold, the parameter is judged to be normal and no adjustment action is performed; if the deviation value is greater than or equal to the deviation threshold, the parameter is judged to be abnormal and the adjustment procedure in step S4 is triggered.

[0008] Optionally, in step S4, the adjustment command includes inert gas production adjustment, specifically: When the real-time inert gas output is higher than the preset value or the deviation value is greater than or equal to the threshold, the control device outputs a command to reduce the fan speed and reduce the air supply. When the real-time inert gas output is lower than the preset value or the deviation value is greater than or equal to the threshold, the control device outputs a command to increase the fan speed and increase the air supply.

[0009] Optionally, in step S4, the adjustment command includes adjusting the inert gas oxygen content, specifically: When the real-time inert gas oxygen content is higher than the preset value or the deviation value is greater than or equal to the threshold, the control device outputs a command to increase the fuel supply pressure of the fuel supply unit and increase the fuel supply. When the real-time inert gas oxygen content is lower than the preset value or the deviation value is greater than or equal to the threshold, the control device outputs a command to increase the burner damper opening to increase the air supply flow, while reducing the oil supply pressure of the oil supply unit to reduce the fuel supply. When the oxygen content in the liquid cargo tank is detected to be close to the limit, the control device triggers the adjustment action in advance and adjusts the control precision.

[0010] Optionally, in step S4, the adjustment command includes pressure adjustment, specifically: Inert gas generator outlet pressure regulation: When the real-time pressure is higher than the upper limit of the preset range, increase the opening of the inert gas regulating valve; when the real-time pressure is lower than the lower limit of the preset range, decrease the opening of the inert gas regulating valve. Inert gas main pressure regulation: When the real-time pressure is higher than the upper limit of the preset range, increase the opening of the vent valve to release excess inert gas to the atmosphere; when the real-time pressure is lower than the lower limit of the preset range, decrease the opening of the vent valve.

[0011] Optionally, in step S4, the adjustment command further includes inert gas temperature adjustment, specifically: Temperature data is collected by the inert gas temperature sensor at the outlet of the inert gas generator. When the real-time temperature is higher than the preset delivery temperature, the speed of the variable frequency water pump in the cooling water supply equipment is increased to increase the cooling water volume; when the real-time temperature is lower than the preset delivery temperature, the speed of the variable frequency water pump is reduced to decrease the cooling water volume.

[0012] Optionally, it also includes emergency response procedures: When abnormal sensor data is detected, parameters continuously exceed the preset range after the adjustment command is executed, or critical equipment malfunctions, the control device immediately issues an audible and visual alarm, records the fault information, and switches the system to manual adjustment mode.

[0013] Optionally, in step S5, continuous closed-loop adjustment is used to ensure that the oxygen content of the gas in the dangerous goods liquid cargo tank of the ship is not higher than 8%VOL, so that the compartment is kept in an inert state that does not support combustion and explosion; and the control device records parameter data, adjustment actions and equipment operating status in real time to form a system operation log.

[0014] Optionally, the air supply equipment is a variable frequency fan, the oil supply equipment is an oil supply unit equipped with a variable frequency oil pump, and the cooling water supply equipment is a cooling water unit equipped with a variable frequency water pump; the monitoring equipment includes a fan outlet pressure sensor, an inert gas generator outlet pressure sensor, an inert gas temperature sensor, an oxygen content sensor, and an inert gas main pipe pressure sensor; the control device is a system monitoring unit, which has the functions of data reception, parameter analysis, adjustment command output, fault alarm, and data recording.

[0015] The present invention provides an automatic adjustment method for a marine combustion-type inert gas system, which has the following beneficial effects: By constructing a fully automated control system of "real-time monitoring, intelligent comparison, and multi-parameter linkage closed-loop adjustment," and innovatively adopting a two-way coordinated and pressure-graded linkage strategy for fan speed and oil supply pressure, the oxygen content of inert gas is precisely stabilized within the optimal range of 3%-4% VOL. This completely solves the problems of lag, low precision, and system fluctuations caused by single-parameter adjustment in traditional manual adjustment. At the same time, it has dual safety monitoring and fault emergency switching mechanisms, which significantly reduce the labor intensity of crew members and eliminate the risk of human operation, while ensuring that the dangerous goods liquid cargo tanks of the ship are always in a high-safety inertization state in accordance with CCS specifications. It also has significant advantages such as no need for large-scale hardware modification, strong adaptability, and low cost.

[0016] In summary, this invention achieves precise and stable control of key indicators such as inert gas oxygen content through multi-parameter linkage closed-loop automatic adjustment and fault emergency mechanism, which greatly reduces reliance on manual labor while ensuring that the ship's liquid cargo tanks are always in a high-safety inertization state.

[0017] Other features and advantages of the invention will become clear from the following detailed description of exemplary embodiments of the invention with reference to the accompanying drawings. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the invention and, together with their description, serve to explain the principles of the invention.

[0019] Figure 1 This is a schematic diagram of the composition of a marine combustion-type inert gas system provided in an embodiment of the present invention; Figure 2 A flow rate regulation flowchart of an automatic regulation method for a marine combustion-type inert gas system provided in an embodiment of the present invention; Figure 3 A flowchart illustrating the oxygen content adjustment process of an automatic adjustment method for a marine combustion-type inert gas system provided in an embodiment of the present invention; Figure 4 A flowchart illustrating the inert gas generator outlet pressure regulation method of the automatic regulation method for a marine combustion-type inert gas system provided in an embodiment of the present invention. Figure 5 A flowchart illustrating the inert gas main pressure regulation process of the automatic adjustment method for a marine combustion-type inert gas system provided in an embodiment of the present invention.

[0020] In the diagram: 01. Fan; 02. First air supply pipeline; 03. Fan outlet valve; 04. Second air supply pipeline; 05. Inert gas generator; 06. First inert gas pipeline; 07. Inert gas regulating valve; 08. Second inert gas pipeline; 09. Inert gas delivery valve; 10. Third inert gas pipeline; 11. Liquid cargo tank; 12. Fan outlet pressure sensor; 13. Oil supply unit; 14. Oil supply pipeline; 15. Water supply pipeline; 16. Cooling water unit; 17. Inert gas generator outlet pressure sensor; 18. Inert gas temperature sensor; 19. Oxygen content sensor; 20. Fifth inert gas pipeline; 21. Exhaust valve; 22. Fourth inert gas pipeline; 23. Inert gas main pipeline pressure sensor; 24. Outboard discharge pipeline; 25. System monitoring unit. Detailed Implementation

[0021] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0022] The following describes, with reference to the accompanying drawings, an automatic adjustment method for a marine combustion-type inert gas system according to an embodiment of the present invention.

[0023] like Figure 1-5 As shown, an automatic adjustment method for a marine combustion-type inert gas system is provided in one embodiment of the present invention. This method is applied to a marine combustion-type inert gas system that includes air supply equipment, inert gas generating equipment, cooling water supply equipment, fuel supply equipment, conveying and discharging equipment, monitoring equipment, and control devices. The method includes the following steps: Step S1: Before the system starts, preset the inert gas production value, inert gas oxygen content value, pressure range, burner fuel supply pressure range, deviation threshold and valve adjustment step value through the control device. Step S2: After the system is running, the monitoring equipment collects real-time data on the power of the fan 01, the oxygen content of the inert gas, the pressure of each key point, the temperature of the inert gas, and the equipment status, and sends it to the control device. Step S3: The control device compares the real-time collected data with the preset benchmark parameters in step S1, calculates the deviation value, and determines whether the deviation value is greater than or equal to the preset deviation threshold. Step S4: When the parameters are determined to be abnormal, the control device outputs an adjustment command to control the speed of the fan 01, the oil supply unit 13, the burner damper, the inert gas regulating valve 07, the exhaust valve 21 and the cooling water pump in a coordinated manner, so that all parameters return to the preset range. Step S5: Repeat steps S2 to S4 to form a closed-loop control mechanism to maintain the inert state in the dangerous goods liquid cargo tanks of the ship.

[0024] In step S2, by monitoring the current and power of the fan 01 and comparing the power-flow curve of the fan 01, the system air supply flow and inert gas production are automatically calculated; the oxygen content of the inert gas is monitored by collecting oxygen content data at the outlet of the inert gas generator 05 through an oxygen sensor; the pressure monitoring includes collecting the air supply pressure through the fan outlet pressure sensor 12, collecting the generator outlet pressure through the inert gas generator outlet pressure sensor 17, and collecting the main pipe pressure through the inert gas main pipe pressure sensor 23.

[0025] In step S4, the adjustment command includes inert gas production adjustment: When the real-time inert gas output is higher than the preset value or the deviation value is greater than or equal to the threshold, the control device outputs a command to reduce the speed of the blower 01 and reduce the air supply. When the real-time inert gas output is lower than the preset value or the deviation value is greater than or equal to the threshold, the control device outputs a command to increase the speed of the fan 01 and increase the air supply.

[0026] In step S4, the adjustment command includes adjusting the inert gas oxygen content: When the real-time inert gas oxygen content is higher than the preset value or the deviation value is greater than or equal to the threshold, the control device outputs a command to increase the oil supply pressure of the oil supply unit 13 and increase the fuel supply. When the real-time inert gas oxygen content is lower than the preset value or the deviation value is greater than or equal to the threshold, the control device outputs a command to increase the burner damper opening to increase the air supply flow, while reducing the oil supply pressure of the oil supply unit 13 to reduce the fuel supply. When the oxygen content in the liquid cargo tank 11 is detected to be close to the limit, the control device triggers the adjustment action in advance and adjusts the control precision to ensure that the oxygen content in the tank is always below the limit.

[0027] In step S4, the adjustment command includes pressure adjustment: Inert gas generator 05 outlet pressure regulation: When the real-time pressure is higher than the upper limit of the preset range, increase the opening of the inert gas regulating valve 07; when the real-time pressure is lower than the lower limit of the preset range, decrease the opening of the inert gas regulating valve 07. Inert gas main pressure regulation: When the real-time pressure is higher than the upper limit of the preset range, increase the opening of the exhaust valve 21 to release excess inert gas to the atmosphere; when the real-time pressure is lower than the lower limit of the preset range, decrease the opening of the exhaust valve 21.

[0028] In step S4, the adjustment command further includes inert gas temperature adjustment: Temperature data is collected by the inert gas temperature sensor 18 at the outlet of the inert gas generator 05. When the real-time temperature is higher than the preset delivery temperature, the speed of the variable frequency water pump in the cooling water supply equipment is increased to increase the cooling water volume; when the real-time temperature is lower than the preset delivery temperature, the speed of the variable frequency water pump is reduced to decrease the cooling water volume.

[0029] In step S1, the preset value of the inert gas oxygen content is set to be no higher than 5% VOL, preferably in the range of 3%-4% VOL; the preset value of the inert gas production is no less than 125% of the ship's maximum unloading capacity.

[0030] In step S3, the parameter comparison specifically includes the following process: Flow comparison: The inert gas production calculated in real time is compared with the preset inert gas production, and the inert gas production adjustment process is determined based on the comparison results. Oxygen content comparison: The real-time collected inert gas oxygen content data is compared with the preset inert gas oxygen content value, and the oxygen content adjustment process is determined based on the comparison result. Pressure comparison: The real-time collected pressure data of the inert gas generator 05 outlet is compared with the preset pressure range, and the pressure regulation process is determined based on the comparison results. Deviation judgment: Calculate the deviation value between each real-time data and the corresponding preset parameter, and compare the deviation value with the preset deviation threshold; if the deviation value is less than the deviation threshold, the parameter is judged to be normal and no adjustment action is performed; if the deviation value is greater than or equal to the deviation threshold, the parameter is judged to be abnormal and the adjustment procedure in step S4 is immediately triggered.

[0031] The method also includes emergency response steps: When abnormal sensor data is detected, parameters continuously exceed the preset range after the adjustment command is executed, or critical equipment malfunctions, the control device immediately issues an audible and visual alarm, records the fault information, and switches the system to manual adjustment mode.

[0032] In step S5, continuous closed-loop regulation is used to ensure that the oxygen content of the gas in the dangerous goods liquid cargo tank of the ship is not higher than 8%VOL, so that the compartment is kept in an inert state that does not support combustion and explosion. At the same time, the control device records parameter data, adjustment actions and equipment operating status in real time to form an operation log.

[0033] In one embodiment, the air supply equipment includes a fan 01 and a fan outlet valve 03, which are used to supply the air required for combustion to the burner. The fan 01 is a variable frequency fan, and the fan flow rate can be adjusted according to the fan power-flow curve to calculate the system inert gas supply flow rate. The fan outlet valve 03 is used to adjust the outlet pressure of the fan 01 so that the fan 01 is in normal working condition.

[0034] The inert gas generating equipment includes an inert gas generator 05 (with a built-in burner, combustion chamber, and scrubbing tower). The burner burns fuel to produce flue gas, which is then fully combusted in the combustion chamber to produce more flue gas. The inert gas is then washed, dusted, and desulfurized by the scrubbing tower before being used as inert gas for subsequent equipment.

[0035] The cooling water supply equipment includes a cooling water unit 16, which provides cooling and washing water to the inert gas generator 05 to ensure that the inert gas does not exceed the maximum allowable delivery temperature. The cooling water unit 16 uses a variable frequency water pump, which automatically adjusts the frequency of the variable frequency water pump motor when the inert gas temperature exceeds the set range, so as to adjust the cooling water pressure and water volume of the inert gas generator 05 and restore the inert gas temperature to the set temperature range.

[0036] The fuel supply equipment includes a fuel supply unit 13, which is used to supply fuel required for combustion to the burner. It can regulate the fuel supply pressure to ensure the fuel combustion is complete. The fuel supply unit 13 uses a variable frequency oil pump, and the fuel supply is automatically adjusted by adjusting the speed of the variable frequency oil pump to keep the oxygen content in the inert gas generated by combustion within a set range.

[0037] The conveying and discharging equipment includes an inert gas regulating valve 07, an exhaust valve 21, and an inert gas delivery valve 09. The inert gas regulating valve 07 is used to regulate the pressure at the outlet of the inert gas generator 05 to ensure that the pressure inside the combustion chamber is kept within the optimal range. The inert gas delivery valve 09 is used to deliver qualified inert gas to the dangerous goods liquid cargo tank 11 of the ship. The exhaust valve 21 is used to discharge the inert gas to the atmosphere when the inert gas parameters are not qualified, so as to prevent unqualified inert gas from entering the dangerous goods liquid cargo tank 11 of the ship, and at the same time regulate the pressure of the inert gas delivered to the dangerous goods liquid cargo tank 11 of the ship.

[0038] The monitoring equipment includes a fan outlet pressure sensor 12, an inert gas generator outlet pressure sensor 17, an inert gas temperature sensor 18, an oxygen content sensor 19, and an inert gas main pipe pressure sensor 23. The oxygen content sensor 19 is used to collect the oxygen content of the inert gas at the outlet of the inert gas generator. Each pressure sensor collects the pressure data at its corresponding location. The inert gas temperature sensor 18 collects the temperature data of the inert gas at the outlet of the inert gas generator 05.

[0039] It also includes a piping system, which comprises an air supply pipeline, an oil supply pipeline 14, an inert gas pipeline, and a seawater pipeline, used for the transportation of air, fuel, inert gas, and cooling water, respectively. Specifically: the air supply pipeline includes a first air supply pipeline 02 and a second air supply pipeline 04, and the fan 01 is connected to the inert gas generator 05 sequentially through the first air supply pipeline 02, the fan outlet valve 03, and the second air supply pipeline 04; the oil supply unit 13 is connected to the inert gas generator 05 through the oil supply pipeline 14; the inert gas pipeline includes a first inert gas pipeline 06, a second inert gas pipeline 08, a third inert gas pipeline 10, a fourth inert gas pipeline 22, and a fifth inert gas pipeline 20, and the inert gas generator 05 is connected to the inert gas regulating valve 07 through the first inert gas pipeline 06. The inert gas regulating valve 07 is connected to the inert gas delivery valve 09 via the second inert gas pipeline 08. The inert gas delivery valve 09 is connected to the liquid cargo tank via the third inert gas pipeline 10. The vent valve 21 is connected to the second inert gas pipeline 08 via the fourth inert gas pipeline 22. The vent valve 21 is also connected to the atmosphere via the fifth inert gas pipeline 20. The seawater pipeline includes a water supply pipeline 15. The cooling water unit 16 is connected to the inert gas generator 05 via the water supply pipeline 15. The inert gas generator 05 is also connected to the overboard discharge pipeline 24 for discharging cooling water overboard.

[0040] The control device includes a system monitoring unit 25, which is used to receive real-time data transmitted by various sensors, perform parameter comparison and analysis, output adjustment commands, control the operation of various valves, oil supply unit 13, cooling water unit 16 and other equipment, realize automatic adjustment function, and also has auxiliary functions such as data recording and fault alarm.

[0041] In a preferred embodiment of the present invention, the control device's built-in adjustment logic employs a hierarchical PID (proportional-integral-derivative) control algorithm. Specifically, for key parameters such as inert gas oxygen content and pressure, when the deviation exceeds a first threshold (e.g., 50% of the deviation threshold) but is less than a preset deviation threshold, proportional (P) control is used to coarsely adjust the parameters at a slower rate and with larger step values, allowing the parameters to quickly approach the target range. When the deviation shrinks to less than the first threshold, the system automatically switches to proportional-integral (PI) control to eliminate static errors and achieve fine adjustment. When parameters fluctuate frequently or are disturbed, proportional-integral-derivative (PID) control is activated. By predicting the error change trend through derivative action, reverse adjustment is applied in advance, enhancing the system's dynamic response capability and stability. This hierarchical PID control strategy effectively balances the contradiction between the system's rapid response and stable adjustment, avoiding overshoot and oscillation.

[0042] To further improve system reliability, in another embodiment, redundant sensors can be installed at key monitoring points (such as the oxygen content at the inert gas generator outlet and the pressure in the inert gas main). The control device simultaneously receives signals from two sensors of the same type and compares them. When the readings of the two sensors deviate from a preset allowable range, one sensor is determined to be faulty. The system immediately issues a sensor fault alarm, automatically masks the abnormal data, switches to control using the sensor with the normal reading, and prompts the crew to perform maintenance. If both sensors fail simultaneously, the system forcibly switches to manual mode and issues an emergency alarm. This redundancy design effectively avoids misadjustment or system downtime caused by the failure of a single sensor, further enhancing the safety and continuity of the system.

[0043] The automatic adjustment method of this invention strictly meets the relevant requirements for inert gas systems in the China Classification Society (CCS) "Code for Construction and Equipment of Ships Carrying Dangerous Chemicals in Bulk". Through the aforementioned closed-loop linkage adjustment, the system can stably control the oxygen content at the outlet of the inert gas generator within the range of 3.5%VOL ± 0.5%VOL, far exceeding the upper limit of 8%VOL required by the code. Simultaneously, the inert gas delivery pressure can be precisely adjusted according to the set pressure of the breather valve in the liquid cargo tank, ensuring that the pressure is always maintained between 1.15 and 1.25 times atmospheric pressure. This effectively prevents air infiltration and avoids triggering the breather valve or damaging the tank structure due to excessive pressure. The inert gas delivery temperature is stably controlled within a safe range of 5°C below the ambient temperature or an absolute temperature not exceeding 40°C through frequency conversion regulation of the cooling water unit, effectively reducing the thermal radiation impact of inert gas on the liquid cargo tank. These precise control indicators fully demonstrate the significant advantages of the method of this invention in improving the inherent safety of ship transportation.

[0044] The above embodiments of the present invention provide an automatic adjustment method for a marine combustion-type inert gas system, the main advantages of which are as follows: 1) This invention overcomes the limitations of existing technologies, such as single-parameter adjustment and the lag and low precision of manual adjustment. Through a closed-loop logic of "real-time monitoring - parameter comparison - automatic adjustment - continuous feedback," it achieves fully automated and precise control of core parameters such as inert gas oxygen content, pressure, and temperature. In particular, for the critical indicator of oxygen content, it adopts a two-way coordinated adjustment mode of "fan speed + oil supply pressure" (increasing oil supply when oxygen content is too high and increasing air supply and decreasing oil supply when oxygen content is too low), stably maintaining it within the preferred range of 3%-4% VOL. This strictly conforms to CCS specifications, ensuring that the ship's dangerous goods liquid cargo tank 11 is always in a safe inertized state that does not support combustion or explosion (oxygen content <8% VOL), making it particularly suitable for chemical transport ships with extremely high requirements for inert gas quality.

[0045] 2) This invention innovatively designs a multi-parameter hierarchical linkage adjustment strategy, avoiding system oscillations caused by single-parameter adjustment: By decoupling and linking the air supply pressure and the inert gas delivery pressure, when the outlet pressure of the inert gas generator 05 is abnormal, the relevant valves are adjusted first. When the pressure of the inert gas main pipe is abnormal, the delivery valve and the exhaust valve 21 are adjusted in tandem. The impact on oxygen content is considered simultaneously during the adjustment process, which solves the problem of disconnect between pressure regulation and oxygen content regulation in traditional technology.

[0046] By incorporating the cooling water unit 16 into the linkage system, the cooling water volume is automatically adjusted according to the inert gas temperature. This ensures that the purity of the inert gas and the delivery temperature meet the standards, while achieving dynamic balance throughout the entire process of generation, purification, and delivery, effectively extending the service life of the equipment.

[0047] 3) This invention achieves full automation from parameter monitoring and deviation analysis to command execution. The control device automatically completes complex calculations and logical judgments, eliminating the need for continuous operator monitoring and frequent manual adjustments, significantly reducing the workload of crew members. Simultaneously, it completely eliminates safety hazards caused by differences in human experience, delayed responses, or operational errors, significantly improving the reliability and consistency of system operation.

[0048] 4) This invention constructs a comprehensive security protection network: The system incorporates dual oxygen content monitoring at the outlet of the inert gas generator 05 and inside the liquid cargo tank 11, providing dual assurance of source control and end-point verification.

[0049] It possesses comprehensive fault diagnosis and emergency handling functions, covering scenarios such as sensor failure, ineffective adjustment actions, and equipment malfunction. Once an anomaly is detected, the system immediately issues audible and visual alarms, logs the information, and seamlessly switches to manual emergency mode to ensure that the system can maintain basic operation or safely shut down under extreme conditions, maximizing the safety of ship transportation.

[0050] 5) This solution is highly versatile and practical, and can be widely adapted to various types of dangerous goods liquid cargo ships using combustion-type inert gas systems. Implementation requires no large-scale modification of existing hardware systems; intelligent upgrades can be achieved primarily through optimizing control logic algorithms and adding a small number of necessary sensors. This solution is easy to implement, cost-effective, and can significantly improve the automation level and safety performance of older ships, demonstrating broad prospects for widespread application.

[0051] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An automatic adjustment method for a marine combustion-type inert gas system, applied to a marine combustion-type inert gas system comprising air supply equipment, inert gas generating equipment, cooling water supply equipment, fuel supply equipment, conveying and discharging equipment, monitoring equipment, and control devices, characterized in that, Includes the following steps: S1. The control device presets the inert gas production preset value, inert gas oxygen content preset value, pressure preset range, burner oil supply pressure preset range, deviation threshold and valve adjustment step value. S2. After the system is running, the monitoring device collects real-time data on fan power, inert gas oxygen content, pressure at key points of the system, inert gas temperature and equipment status, and sends the collected data to the control device. S3. The control device compares the real-time collected data with the preset benchmark parameters in step S1, calculates the deviation value, and determines whether the deviation value is greater than or equal to the preset deviation threshold. S4. When the parameters are determined to be abnormal, the control device outputs an adjustment command to control the fan speed, oil supply unit, burner damper, inert gas regulating valve, exhaust valve and cooling water pump in a coordinated manner, so that the parameters return to the preset range. S5. Repeat steps S2 to S4 to form a closed-loop regulation mechanism to maintain the inert state in the dangerous goods liquid cargo tanks of the ship.

2. The automatic adjustment method for a marine combustion-type inert gas system according to claim 1, characterized in that, In step S2, the specific methods of data collection include: By monitoring the fan current and power, and comparing the fan's power-flow curve, the system automatically calculates the air supply flow and inert gas production. The oxygen content data of inert gas at the outlet of the inert gas generator is collected by an oxygen content sensor. Pressure sensors are used to collect the air supply pressure at the fan outlet, the inert gas generator outlet pressure, and the inert gas main pipe pressure.

3. The automatic adjustment method for a marine combustion-type inert gas system according to claim 1, characterized in that, In step S3, the specific process of parameter comparison and deviation judgment is as follows: The flow rate, oxygen content, and pressure are compared sequentially, and then a deviation judgment is made. The flow rate comparison is to compare the real-time automatically calculated inert gas output with the preset inert gas output. The oxygen content comparison is to compare the real-time collected inert gas oxygen content data with the preset inert gas oxygen content value. The pressure comparison is to compare the real-time collected inert gas generator outlet pressure data with the preset pressure range. If the deviation value is less than the deviation threshold, the parameter is judged to be normal and no adjustment action is performed; if the deviation value is greater than or equal to the deviation threshold, the parameter is judged to be abnormal and the adjustment procedure in step S4 is triggered.

4. The automatic adjustment method for a marine combustion-type inert gas system according to any one of claims 1-3, characterized in that, In step S4, the adjustment command includes inert gas production adjustment, specifically: When the real-time inert gas output is higher than the preset value or the deviation value is greater than or equal to the threshold, the control device outputs a command to reduce the fan speed and reduce the air supply. When the real-time inert gas output is lower than the preset value or the deviation value is greater than or equal to the threshold, the control device outputs a command to increase the fan speed and increase the air supply.

5. The automatic adjustment method for a marine combustion-type inert gas system according to claim 4, characterized in that, In step S4, the adjustment command includes adjusting the inert gas oxygen content, specifically: When the real-time inert gas oxygen content is higher than the preset value or the deviation value is greater than or equal to the threshold, the control device outputs a command to increase the fuel supply pressure of the fuel supply unit and increase the fuel supply. When the real-time inert gas oxygen content is lower than the preset value or the deviation value is greater than or equal to the threshold, the control device outputs a command to increase the burner damper opening to increase the air supply flow, while reducing the oil supply pressure of the oil supply unit to reduce the fuel supply. When the oxygen content in the liquid cargo tank is detected to be close to the limit, the control device triggers the adjustment action in advance and adjusts the control precision.

6. The automatic adjustment method for a marine combustion-type inert gas system according to claim 5, characterized in that, In step S4, the adjustment command includes pressure adjustment, specifically: Inert gas generator outlet pressure regulation: When the real-time pressure is higher than the upper limit of the preset range, increase the opening of the inert gas regulating valve; when the real-time pressure is lower than the lower limit of the preset range, decrease the opening of the inert gas regulating valve. Inert gas main pressure regulation: When the real-time pressure is higher than the upper limit of the preset range, increase the opening of the vent valve to release excess inert gas to the atmosphere; when the real-time pressure is lower than the lower limit of the preset range, decrease the opening of the vent valve.

7. The automatic adjustment method for a marine combustion-type inert gas system according to claim 6, characterized in that, In step S4, the adjustment command further includes inert gas temperature adjustment, specifically: Temperature data is collected by an inert gas temperature sensor at the outlet of the inert gas generator. When the real-time temperature is higher than the preset delivery temperature, the speed of the variable frequency water pump in the cooling water supply equipment is increased to increase the cooling water volume. When the real-time temperature is lower than the preset delivery temperature, the speed of the variable frequency water pump is reduced to decrease the cooling water volume.

8. The automatic adjustment method for a marine combustion-type inert gas system according to claim 1, characterized in that, It also includes emergency troubleshooting steps: When abnormal sensor data is detected, parameters continuously exceed the preset range after the adjustment command is executed, or critical equipment malfunctions, the control device immediately issues an audible and visual alarm, records the fault information, and switches the system to manual adjustment mode.

9. The automatic adjustment method for a marine combustion-type inert gas system according to claim 1, characterized in that, In step S5, through continuous closed-loop regulation, the oxygen content of the gas in the dangerous goods liquid cargo tank of the ship is ensured to be no higher than 8%VOL, so that the compartment is kept in an inert state that does not support combustion and explosion. Furthermore, the control device records parameter data, adjustment actions, and equipment operating status in real time, forming a system operation log.

10. The automatic adjustment method for a marine combustion-type inert gas system according to claim 1, characterized in that, The air supply equipment is a variable frequency fan; The oil supply equipment is an oil supply unit equipped with a variable frequency oil pump; The cooling water supply equipment is a cooling water unit equipped with a variable frequency water pump; The monitoring equipment includes a fan outlet pressure sensor, an inert gas generator outlet pressure sensor, an inert gas temperature sensor, an oxygen content sensor, and an inert gas main pipe pressure sensor. The control device is a system monitoring unit, which has the functions of data reception, parameter analysis, adjustment command output, fault alarm and data recording.

Images