An early warning method for monitoring abnormal temperature status of ships carrying dangerous goods

Abstract

The present invention discloses an early warning method for monitoring abnormal temperature conditions of ships carrying dangerous goods. The early warning method is divided into four parts: installation of monitoring equipment, determination of temperature abnormality parameters, calculation of temperature abnormality indicators, and grading of temperature abnormality levels. The present invention utilizes infrared thermal imaging temperature measurement methods to achieve spatial overall temperature measurement of the temperature field of all key hazardous locations on ships carrying dangerous goods. It utilizes multiple indicators that can objectively reflect the temperature abnormality and calculates the level of temperature abnormality on ships carrying dangerous goods based on a comprehensive temperature assessment strategy. The application of the present invention has the advantages of accurate advance warning, strong environmental adaptability, low false alarm rate, strong resistance to interference factors, good feasibility and operability, and provides an effective technical method for shipping management departments to implement accurate and effective hierarchical control.

Description

Technical Field

[0001] The present invention relates to a ship monitoring and early warning method, and in particular to an early warning method for monitoring abnormal temperature status of a ship carrying dangerous goods. Background Art

[0002] With the rapid development of my country's national economy and industrial production, the demand and use of flammable and explosive petrochemicals and chemicals, as raw materials, intermediates, or finished products for industrial production and people's daily lives, has increased dramatically in recent years. As a major producer, user, importer, and consumer of hazardous chemicals, my country has always attached great importance to the safe production of hazardous chemicals. As a key mode of cargo transportation, accidents during the transport of hazardous chemicals by water can have serious adverse impacts on waterways, nearby ships, surrounding buildings, people's lives, and industrial production. Hazardous chemicals are flammable, explosive, toxic, and hazardous, making them highly susceptible to serious accidents such as leaks, fires, and explosions during transportation. The occurrence, development, and spread of these accidents are closely related to temperature. A comprehensive evaluation index and real-time temperature data collection at key locations during the transportation of dangerous goods, along with a comprehensive evaluation index, can objectively and comprehensively reflect the safety level of the risk of explosion and ignition of dangerous goods due to excessively high temperatures, thereby providing early warning of accidents caused by temperature fluctuations in the dangerous goods themselves or by high temperatures in the hull or onboard equipment.

[0003] At present, ships carrying dangerous goods mainly perceive temperature through two ways: installing point temperature sensors in cargo holds to monitor the temperature changes of cargo in independent cargo holds, and installing point temperature-sensitive fire detectors on the ceilings of manned areas to detect whether there is a fire. However, the high-temperature risk points on board that lead to fire and explosion accidents of dangerous goods are scattered and numerous. The deck and cargo hold hatch covers in hot weather, high-temperature piping systems with damaged insulation materials, power supply lines and electrical cabinets in abnormal conditions such as short circuits and loose joints, personnel illegally using fire and smoking, and flying fires in areas around the ship may all cause dangerous goods to burn and explode. Existing temperature measurement technology and personnel system management alone cannot achieve comprehensive, accurate, comprehensive, dynamic, and large-scale temperature field monitoring and early warning for dangerous places on ships carrying dangerous goods that may cause combustion and explosion.

[0004] In addition, due to the significant differences in the internal ambient temperature of different dangerous places on the ship and the temperature differences between numerous facilities and equipment, some equipment is in a medium-high temperature state for a long time during normal operation, and under non-accident conditions, the external air circulation affects the spatial temperature of the place. The traditional high-temperature threshold over-limit alarm method often cannot objectively reflect the overall over-temperature risk level of the ship, and is prone to omissions and misreporting. It cannot meet the current safety risk management requirements of relevant shipping management departments for water transportation of dangerous goods. Summary of the Invention

[0005] In order to overcome the deficiencies of the prior art, the present invention provides an early warning method for monitoring abnormal temperature conditions of a ship carrying dangerous goods.

[0006] The technical solution adopted by the present invention is: an early warning method for monitoring abnormal temperature status of ships carrying dangerous goods is divided into four parts: monitoring equipment installation, temperature abnormality status parameter determination, temperature abnormality index calculation, and temperature abnormality status level classification. The four steps are as follows:

[0007] Step 1: Install monitoring equipment

[0008] Identify various safety risks of ships carrying dangerous goods during the shipping process, and determine the areas that need to be monitored on ships carrying dangerous goods. The monitoring equipment includes infrared thermal imagers and remote centralized data acquisition software. Infrared thermal imagers are set in the key monitoring areas of ships carrying dangerous goods. Each key monitoring area of ​​ships carrying dangerous goods is equipped with no less than one infrared thermal imager, and the image acquisition range of the infrared thermal imager is no less than 60% of the total space of each key monitoring area.

[0009] Step 2: Determine the temperature abnormality state parameters

[0010] 1. First, set the parameter code and the corresponding code definition. The parameter code and the corresponding code definition are shown in the table below:

[0011]

[0012]

[0013]

[0014] 2. Use remote centralized data acquisition software to collect thermal images from all infrared thermal imagers installed on ships carrying dangerous goods. The thermal image collected by the i-th infrared thermal imager is divided into j monitoring areas according to the key objects of attention.

[0015] 3. According to the temperature history data of each monitoring area of ​​the ship carrying dangerous goods under normal working conditions, set the corresponding alarm temperature upper limit BJT for each monitoring area ij , upper limit of heating rate SWT ij , Over-temperature pixel alarm point upper limit DS ij , Over-temperature pixel alarm point growth rate upper limit DSV ij , Over-temperature pixel alarm ratio upper limit ZB ij .

[0016] 4. Set the regional risk weight value QZ according to the danger and importance of each monitoring area during the navigation of ships carrying dangerous goods ij .

[0017] 5. Set the over-temperature state weight value ZS according to the temperature development characteristics of the potential explosion accident of the ship carrying dangerous goods cwt , Temperature rise state weight value ZS swv , over-temperature pixel state weight value ZS cwd , Over-temperature pixel alarm point growth state weight value ZS cdv , Over-temperature pixel alarm ratio status weight value ZS czb .

[0018] Step 3: Calculation of temperature anomaly index

[0019] a. The temperature of all pixels in each monitoring area and the corresponding upper limit of the alarm temperature BJT ij If there is at least one pixel whose temperature value is greater than or equal to the upper limit of the alarm temperature, BJT ij , then the over-temperature state CWT of the jth area of ​​the image collected by the i-th infrared thermal imager is ij =1, otherwise CWT ij =0.

[0020] b. The difference between the temperature value of all pixels in each monitoring area and the temperature value t seconds ago and the corresponding upper limit of the heating rate SWT ij If there is at least one pixel difference greater than or equal to the upper limit of the heating rate SWT ij , then the temperature rise rate state SWV of the jth area of ​​the image collected by the i-th infrared thermal imager is ij =1, otherwise SWV ij =0.

[0021] c. All real-time temperatures in the monitoring area are greater than the alarm temperature upper limit BJT ij When the total number of pixels is greater than or equal to the upper limit DS of the over-temperature pixel alarm point ij , then the over-temperature pixel count state CWD of the jth area of ​​the image captured by the i-th infrared thermal imager is ij =1, otherwise CWD ij =0.

[0022] d. Calculate all real-time temperatures in the monitoring area that are greater than the alarm temperature upper limit BJT ij The difference between the total number of pixels and the number before the temperature sampling interval t seconds, if the difference is greater than or equal to the upper limit DSV of the growth rate of the over-temperature pixel alarm point ij, then the over-temperature pixel alarm point growth state CDV of the jth area of ​​the image collected by the i-th infrared thermal imager is ij =1, otherwise CDV ij =0.

[0023] e. Calculate all real-time temperatures in the monitoring area that are greater than the alarm temperature upper limit BJT ij The ratio of the total number of pixels to the total number of pixels in the monitoring area, if the ratio is greater than or equal to the upper limit ZB of the over-temperature pixel alarm ratio ij , then the over-temperature pixel alarm ratio state CZB of the jth area of ​​the image collected by the i-th infrared thermal imager is ij =1, otherwise CZB ij = 0. f. Construct the over-temperature state vector CWT of the i-th infrared thermal imager according to the following formula: i , the over-temperature state vector CWT of all infrared thermal imagers on the ship and the risk weight vector QZ of the i-th infrared thermal imager i , the risk weight vector QZ of all infrared thermal imagers on board, and calculate the over-temperature state level value CWT lev :

[0024]

[0025] CWT lev =CWT·QZ.

[0026] g. Construct the temperature rise speed state vector SWV of the i-th infrared thermal imager according to the following formula: i and the temperature rise speed state vector SWV of all infrared thermal imagers on the ship, and calculate the temperature rise speed level value SWV lev :

[0027]

[0028] SWV lev =SWV·QZ.

[0029] h. Construct the over-temperature pixel count state vector CWD of the i-th infrared thermal imager according to the following formula: i and the state vector CWD of the number of over-temperature pixels of all infrared thermal imagers on the ship, and calculate the level value CWD of the number of over-temperature pixels lev :

[0030]

[0031] CWD lev =CWD·QZ.

[0032] i. Construct the over-temperature pixel alarm point growth state vector CDV of the i-th infrared thermal imager according to the following formula:i and the over-temperature pixel alarm point growth state vector CDV of all infrared thermal imagers of the ship, and calculate the over-temperature pixel alarm point growth level value CDV lev :

[0033]

[0034] CDV lev =CDV·QZ.

[0035] j. Construct the over-temperature pixel alarm ratio state vector CZB of the i-th infrared thermal imager according to the following formula: i And the over-temperature pixel alarm ratio state vector CZB of all infrared thermal imagers of the ship, and calculate the over-temperature pixel alarm ratio level value CZB lev :

[0036] CZB lev =CZB·QZ.

[0037] k. Construct the abnormal state vector YCZT and the temperature development change characteristic vector ZS according to the following formula, and calculate the abnormal state level value YCZT lev :

[0038]

[0039] YCZT lev =YCZT·ZS.

[0040] Step 4: Classification of abnormal temperature status

[0041] According to the safety risks of ships carrying dangerous goods, the temperature abnormality level WDYCZT of ships carrying dangerous goods is divided into four levels from severe to mild, namely level 1: emergency linkage disposal level, level 2: navigation emergency organization level, level 3: enterprise remote supervision level, level 4: ship self-investigation level; and three safety thresholds are set, namely: temperature abnormality level 1 state threshold LEV1, temperature abnormality level 2 state threshold LEV2 and temperature abnormality level 3 state threshold LEV3, and LEV3<LEV2<LEV1, and the temperature abnormality level WDYCZT is determined according to the following judgment rules:

[0042] When 0<YCZT lev When ≤LEV3, the abnormal temperature level WDYCZT is level 4;

[0043] When LEV3<YCZT lev When ≤LEV2, the abnormal temperature state level WDYCZT is level 3;

[0044] When LEV2<YCZTlev When ≤LEV1, the abnormal temperature level WDYCZT is level 2;

[0045] When LEV1<YCZT lev When , the abnormal temperature level WDYCZT is level one.

[0046] The beneficial effects of the present invention are: using the infrared thermal imaging temperature measurement method, the overall temperature field space measurement of all key dangerous places on ships carrying dangerous goods is realized, and a variety of indicators that can objectively reflect the abnormal temperature state are used to calculate the safety risk level of ships carrying dangerous goods based on a comprehensive temperature assessment strategy, thereby realizing the rapid identification and early warning of abnormal temperature risks that induce fire and explosion accidents on ships carrying dangerous goods. The application of the present invention has the advantages of accurate advance warning, strong environmental adaptability, low false alarm rate, strong anti-interference factor, good feasibility and operability, etc., which provides an effective technical method for shipping management departments to implement accurate and effective hierarchical control. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a flowchart of an embodiment of the present invention. DETAILED DESCRIPTION

[0048] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0049] Example: Take a chemical tanker with methanol in all cargo holds as an example. During navigation, a fire occurs in the engine room of the main engine, causing the gearbox to burn simultaneously. The following example provides an example of a temperature abnormality alarm:

[0050] (1) Installation of monitoring equipment: Identify various safety risks of chemical tankers during navigation and determine the areas on board that require key monitoring. Two infrared thermal imagers are installed in the ship's engine room, cargo deck, pump room, cockpit, storeroom, kitchen, restaurant, evacuation passage, conference room, fire equipment room and chimney exit. The image acquisition range is capable of monitoring the entire space where it is located. All cargo hatch covers, fuel tanks, piping systems, main engines, gearboxes, clutches, superchargers, batteries and oil pumps on board are within the monitoring coverage of the infrared thermal imager. The infrared thermal imager uses a 4mm fixed-focus lens with a display resolution of 383×288 pixels. The temperature measurement range of the infrared thermal imager covers -20℃-350℃.

[0051] (2) Determination of temperature anomaly state parameters

[0052] 1. First, set the parameter code and the corresponding code definition. The parameter code and the corresponding code definition are shown in the table below:

[0053]

[0054]

[0055]

[0056] 2. Utilize remote centralized data acquisition software to capture thermal images from all thermal imagers installed on the vessel. Using irregular closed patterns, the thermal images captured by each camera are divided into multiple monitoring zones based on key objects of interest, such as equipment, pipelines and cabinets, walls and ceilings, and floors. For example, consider the first thermal imager, located in the engine room. The image captured by the first camera includes five objects of interest: the main engine, gearbox, high-temperature piping, walls, and floor. Using irregular patterns, the software divides the 383×288 pixel image into five zones: monitoring zone 1 for the main engine, zone 2 for the gearbox, zone 3 for the high-temperature piping, zone 4 for the walls, and zone 5 for the floor. The same process applies to the remaining thermal imagers.

[0057] 3. According to the temperature history data of each monitoring area of ​​the ship under normal working conditions, set the corresponding alarm temperature upper limit BJT for each monitoring area ij , upper limit of heating rate SWT ij , Over-temperature pixel alarm point upper limit DS ij , Over-temperature pixel alarm point growth rate upper limit DSV ij , Over-temperature pixel alarm ratio upper limit ZB ij These five alarm upper limits objectively reflect the characteristics of potential safety risks from different perspectives. Therefore, the setting of each threshold should be selected in combination with the normal working conditions of the object of concern. ij The critical temperature of the normal state and abnormal state of the object of interest is given, which simply and intuitively represents the real-time state of the object of interest; the upper limit of the heating rate SWT ij The temperature rise rate of the object of concern from normal state to abnormal state is given, which represents the future development trend of the object of concern and plays a role in predicting and warning potential risks before a fire occurs; the upper limit of the over-temperature pixel alarm point DS ij The maximum permissible range of abnormal state of the object of concern in the local position is given, which characterizes the danger level, scope and scale of the abnormal state of the object of concern, and plays the role of automatic distinction between local and overall, small fire and large fire, controllable and uncontrollable; the upper limit of the growth rate of over-temperature pixel alarm points DSV ij The maximum permissible rate of transition of the abnormal state of the object of concern from local to overall development is given, which is an important indicator to characterize the speed of fire development and provide guidance for the efficiency of subsequent emergency rescue operations; the upper limit of the proportion of over-temperature pixel alarms ZB ijUpper limit DS of over-temperature pixel alarm points ij Based on this, the allowable critical value of the proportion of the abnormal state area of ​​the object of concern to the entire whole is given, which represents the possible risk that the object of concern will lose all its operating functions.

[0058] Taking the first infrared thermal imager as an example, due to the characteristics of the host's high normal operating temperature, relatively fixed internal heating components and positions, and the host's temperature rise speed from cold to hot state is moderate, the BJT is set 11 =100℃、SWT 11 =10℃ / s、DS 11 =15000point,DSV 11 =100point / s, ZB 11 =35%; Due to the normal working temperature of the gearbox, the temperature of the entire box is relatively uniform, and the temperature change rate from cold to hot is slow, so BJT is set 12 =60℃、SWT 12 =3℃ / s, DS 12 =30000point,DSV 12 =80point / s, ZB 12 = 50%; Due to the characteristics of high temperature pipes, unless the outer insulation material is damaged, the outer layer is usually at a lower temperature and the temperature rise rate is extremely slow, so BJT is set 13 =30℃、SWT 13 =2℃ / s, DS 13 =30000point,DSV 13 =80point / s, ZB 12 =50%; The walls and floors on the ship are important components for preventing the spread of fire and for fireproofing the cabin space. Since the bearing capacity and integrity of steel materials are damaged under high temperatures, it is particularly important to monitor their temperature and temperature changes. Considering that the walls and floors are usually at ambient temperature, the walls and floors in the engine room are not affected by sunlight, etc., and the temperature changes are extremely slow, so BJT is set. 14 =BJT 15 =30℃、SWT 14 =SWT 15 =2℃ / s, DS 14 =DS 15 =30000point,DSV 14 =DSV 15 =80point / s, ZB 14 =ZB 15 =50%.

[0059] 4. Set regional risk weight value QZ according to the danger and importance of each monitoring area during the ship's navigation process ij Taking the first infrared thermal imager as an example, the main engine and gearbox are key equipment in the ship's power system. Their importance is self-evident. 11 =QZ 12 =1; Damage to the insulation layer of the high-temperature piping system may ignite the leaked oil in the engine room due to the high temperature at the damaged area, which is of great importance. 13 =0.8, walls and floors are relatively less important due to their non-combustible steel properties, QZ 13 =0.2.

[0060] 5. Set the over-temperature state weight value ZS according to the temperature development and change characteristics of the ship's potential explosion accident cwt , Temperature rise state weight value ZS swv , over-temperature pixel state weight value ZS cwd , Over-temperature pixel alarm point growth state weight value ZS cdv , Over-temperature pixel alarm ratio status weight value ZS czb Since methanol is a volatile liquid and a Class A fire hazard, it may explode and burn the entire ship if it encounters high temperatures after leakage. Therefore, chemical tankers carrying methanol should focus on the overtemperature status and heating rate of each monitoring area, while the other three indicators are relatively less important. Therefore, ZS is set. cwt =ZS swv =1, ZS cwd =ZS cdv =ZS czb =0.5.

[0061] (3) Calculation of temperature anomaly index

[0062] a. The temperature of all pixels in each monitoring area and the corresponding alarm temperature upper limit BJT ij Compare, if there is at least one pixel whose temperature value is greater than or equal to BJT ij , then the over-temperature state CWT ij =1, otherwise CWT ij = 0. Due to the fire in the main engine and gearbox, the current temperature exceeds 200℃, so CWT 11 =CWT 12 =1, the rest CWT ij =0.

[0063] b. The difference between the temperature value of all pixels in each monitoring area and the temperature value t seconds ago and the corresponding upper limit of the heating rate SWT ij If there is at least one pixel difference greater than or equal to the upper limit of the heating rate SWT ij, then the temperature rise state SWV ij =1, otherwise SWV ij = 0. After the fire occurred in the main engine and gearbox, the current temperature rose rapidly, and the heating rate was above 30℃ / s, so SWV 11 =SWV 12 =1, the rest of SWV ij =0.

[0064] c. All real-time temperatures in the monitoring area are greater than the alarm temperature upper limit BJT ij When the total number of pixels is greater than or equal to the upper limit of the over-temperature pixel alarm point DS ij , then the over-temperature pixel count state CWD of the jth area of ​​the image collected by the i-th infrared thermal imager is ij =1, otherwise CWD ij = 0. As the combustion of the main engine and gearbox progresses, 23183 points in the 1# monitoring area exceed 100°C, and 35321 points in the 2# monitoring area exceed 60°C. Therefore, CWD 11 =CWD 12 =1, the rest are CWD ij = 0. d. Calculate all real-time temperatures in the monitoring area that are greater than the alarm temperature upper limit BJT ij The difference between the total number of pixels and the number of pixels before the temperature sampling interval t seconds, if the difference is greater than or equal to the upper limit DSV of the growth rate of the over-temperature pixel alarm points ij , then the number of over-temperature pixel alarm points in the jth area of ​​the image collected by the i-th infrared thermal imager is increased by CDV ij =1, otherwise CDV ij = 0. The difference between the total number of pixels with a current real-time temperature greater than 100°C in monitoring area 1# and the number 1 second ago is 212 points / s, and the difference between the total number of pixels with a current real-time temperature greater than 60°C in monitoring area 2# and the number 1 second ago is 136 points / s, so CDV 11 =CDV 12 =1, the rest of CDV ij =0.

[0065] e. Calculate all real-time temperatures within the monitoring area that are greater than the alarm temperature upper limit BJT ij The ratio of the total number of pixels to the total number of pixels in the monitoring area, if the ratio is greater than or equal to the upper limit ZB of the over-temperature pixel alarm ratio ij , then the over-temperature pixel alarm ratio state CZB of the jth area of ​​the image collected by the i-th infrared thermal imager is ij =1, otherwise CZB ij= 0. The ratio of the total number of pixels with a temperature greater than 100°C in the 1# monitoring area to the total number of pixels in the monitoring area is 76%, and the ratio of the total number of pixels with a temperature greater than 60°C in the 2# monitoring area to the total number of pixels in the area is 89%. Therefore, CZB 11 =CZB 12 =1, the rest CZB ij =0.

[0066] f. Construct the over-temperature state vector CWT of the i-th infrared thermal imager according to the following formula: i , the over-temperature state vector CWT of all infrared thermal imagers on the ship and the risk weight vector QZ of the i-th infrared thermal imager i , the risk weight vector QZ of all infrared thermal imagers on board, and calculate the over-temperature state level value CWT lev :

[0067]

[0068] CWT lev =CWT·QZ=2.

[0069] g. Construct the temperature rise speed state vector SWV of the i-th infrared thermal imager according to the following formula i And the temperature rise speed state vector SWV of all infrared thermal imagers on the ship, and calculate the temperature rise speed level SWV lev :

[0070]

[0071] SWV lev =SWV·QZ.

[0072] h. Construct the over-temperature pixel state vector CWD of the i-th infrared thermal imager according to the following formula: i And the over-temperature pixel count state vector CWD of all infrared thermal imagers on the ship, and calculate the over-temperature pixel count level value CWD lev :

[0073]

[0074] CWD lev =CWD·QZ.

[0075] i. Construct the over-temperature pixel alarm point growth state vector CDV of the i-th infrared thermal imager according to the following formula: i And the over-temperature pixel alarm point growth state vector CDV of all infrared thermal imagers on the ship, and calculate the over-temperature pixel alarm point growth level value CDV lev :

[0076] CDV lev=CDV·QZ.

[0077] j. Construct the over-temperature pixel alarm ratio state vector CZB of the i-th infrared thermal imager according to the following formula: i And the over-temperature pixel alarm ratio state vector CZB of all infrared thermal imagers on the ship, and calculate the over-temperature pixel alarm ratio level value CZB lev :

[0078]

[0079] CZB lev =CZB·QZ.

[0080] k. Construct the abnormal state vector YCZT and the temperature development change characteristic vector ZS according to the following formula, and calculate the abnormal state level value YCZT lev :

[0081]

[0082] YCZT lev =YCZT·ZS=7.

[0083] (IV) Classification of temperature anomaly levels

[0084] According to the safety risks and management practices of ships carrying dangerous goods, the temperature anomaly status level WDYCZT of ships carrying dangerous goods is divided into four levels from severe to mild, namely level 1: emergency linkage disposal level, level 2: navigation emergency organization level, level 3: enterprise remote supervision level, and level 4: ship self-inspection level. Three safety thresholds are set, namely: temperature anomaly level 1 threshold LEV1 = 10, temperature anomaly level 2 threshold LEV2 = 5, and temperature anomaly level 3 threshold LEV3 = 1, and LEV3 < LEV2 < LEV1. According to the judgment rules, the temperature anomaly level WDYCZT of this embodiment is determined to be level 2. The judgment rules are as follows:

[0085] When 0<YCZT lev When ≤LEV3, the abnormal temperature level WDYCZT is level 4;

[0086] When LEV3<YCZT lev When ≤LEV2, the abnormal temperature state level WDYCZT is level 3;

[0087] When LEV2<YCZT lev When ≤LEV1, the abnormal temperature level WDYCZT is level 2;

[0088] When LEV1<YCZT lev When , the abnormal temperature level WDYCZT is level one.

[0089] The abnormal temperature state level WDYCZT reaches level 2, indicating that a serious fire or explosion has occurred on the ship. However, the scope and scale of the fire are currently small and limited to a specific area of ​​the ship. It has not yet caused large-scale spread. The accident damage and ship risks are currently within controllable ranges. The shipping management department can communicate with the personnel on board through the ship's own communication system and remotely guide the activation of the fire protection system and the ship's departure from the main channel. Based on this method, the shipping management department can dynamically, accurately and comprehensively grasp the overall temperature anomaly level of ships carrying dangerous goods during navigation. The method fully considers the temperature differences of different objects of concern on the ship under abnormal conditions, objectively characterizes the temperature change trend before the disaster, the degree of danger, scope and scale of the accident during the disaster, the future development trend after the disaster, and the risk of the accident getting out of control, which helps the shipping management department to implement differentiated management and control measures.

Claims

1. An early warning method for monitoring abnormal temperature status of a ship carrying dangerous goods, characterized in that: The early warning method is divided into four parts: installation of monitoring equipment, determination of temperature anomaly parameters, calculation of temperature anomaly indicators, and classification of temperature anomaly levels. The steps of the four parts are as follows: Step 1: Install monitoring equipment Identify various safety risks of ships carrying dangerous goods during navigation and determine areas requiring key monitoring on ships carrying dangerous goods. The monitoring equipment includes infrared thermal imagers and remote centralized data acquisition software. Infrared thermal imagers are installed in key monitoring areas of ships carrying dangerous goods. Each key monitoring area of ​​a ship carrying dangerous goods must be equipped with at least one infrared thermal imager, and the image acquisition range of the infrared thermal imager must be no less than 60% of the total space of each key monitoring area. Step 2: Determine the temperature abnormality state parameters 1. First, set the parameter code and the corresponding code definition. The parameter code and the corresponding code definition are shown in the table below:

2. Use remote centralized data acquisition software to collect thermal images from all infrared thermal imagers installed on ships carrying dangerous goods, and divide the thermal images collected by the i-th infrared thermal imager into j monitoring areas according to the key objects of attention; 3. According to the temperature history data of each monitoring area of ​​the ship carrying dangerous goods under normal working conditions, set the corresponding alarm temperature upper limit BJT for each monitoring area ij , upper limit of heating rate SWT ij , Over-temperature pixel alarm point upper limit DS ij , Over-temperature pixel alarm point growth rate upper limit DSV ij , Over-temperature pixel alarm ratio upper limit ZB ij ; 4. Set the regional risk weight value QZ according to the danger and importance of each monitoring area during the navigation of ships carrying dangerous goods ij ; 5. Set the over-temperature state weight value ZS according to the temperature development characteristics of the potential explosion accident of the ship carrying dangerous goods cwt , Temperature rise state weight value ZS swv , over-temperature pixel state weight value ZS cwd , Over-temperature pixel alarm point growth state weight value ZS cdv , Over-temperature pixel alarm ratio status weight value ZS czb ; Step 3: Calculation of temperature anomaly index a. The temperature of all pixels in each monitoring area and the corresponding upper limit of the alarm temperature BJT ij If there is at least one pixel whose temperature value is greater than or equal to the upper limit of the alarm temperature, BJT ij , then the over-temperature state CWT of the jth area of ​​the image collected by the i-th infrared thermal imager is ij =1, otherwise CWT ij =0; b. The difference between the temperature value of all pixels in each monitoring area and the temperature value t seconds ago and the corresponding upper limit of the heating rate SWT ij If there is at least one pixel difference greater than or equal to the upper limit of the heating rate SWT ij , then the temperature rise rate state SWV of the jth area of ​​the image collected by the i-th infrared thermal imager is ij =1, otherwise SWV ij =0; c. All real-time temperatures in the monitoring area are greater than the alarm temperature upper limit BJT ij When the total number of pixels is greater than or equal to the upper limit DS of the over-temperature pixel alarm point ij , then the over-temperature pixel count state CWD of the jth area of ​​the image captured by the i-th infrared thermal imager is ij =1, otherwise CWD ij =0; d. Calculate all real-time temperatures in the monitoring area that are greater than the alarm temperature upper limit BJT ij The difference between the total number of pixels and the number before the temperature sampling interval t seconds, if the difference is greater than or equal to the upper limit DSV of the growth rate of the over-temperature pixel alarm point ij , then the over-temperature pixel alarm point growth state CDV of the jth area of ​​the image collected by the i-th infrared thermal imager is ij =1, otherwise CDV ij =0; e. Calculate all real-time temperatures in the monitoring area that are greater than the alarm temperature upper limit BJT ij The ratio of the total number of pixels to the total number of pixels in the monitoring area, if the ratio is greater than or equal to the upper limit ZB of the over-temperature pixel alarm ratio ij , then the over-temperature pixel alarm ratio state CZB of the jth area of ​​the image collected by the i-th infrared thermal imager is ij =1, otherwise CZB ij =0; f. Construct the over-temperature state vector CWT of the i-th infrared thermal imager according to the following formula: i , the over-temperature state vector CWT of all infrared thermal imagers on the ship and the risk weight vector QZ of the i-th infrared thermal imager i , the risk weight vector QZ of all infrared thermal imagers on board, and calculate the over-temperature state level value CWT lev : CWT lev =CWT·QZ; g. Construct the temperature rise speed state vector SWV of the i-th infrared thermal imager according to the following formula: i and the temperature rise speed state vector SWV of all infrared thermal imagers on the ship, and calculate the temperature rise speed level value SWV lev : SWV lev =SWV·QZ; h. Construct the over-temperature pixel count state vector CWD of the i-th infrared thermal imager according to the following formula: i and the state vector CWD of the number of over-temperature pixels of all infrared thermal imagers on the ship, and calculate the level value CWD of the number of over-temperature pixels lev : CWD lev =CWD·QZ; i. Construct the over-temperature pixel alarm point growth state vector CDV of the i-th infrared thermal imager according to the following formula: i and the over-temperature pixel alarm point growth state vector CDV of all infrared thermal imagers of the ship, and calculate the over-temperature pixel alarm point growth level value CDV lev : CDV lev =CDV·QZ; j. Construct the over-temperature pixel alarm ratio state vector CZB of the i-th infrared thermal imager according to the following formula: i And the over-temperature pixel alarm ratio state vector CZB of all infrared thermal imagers of the ship, and calculate the over-temperature pixel alarm ratio level value CZB lev : CZB lev =CZB·QZ; k. Construct the abnormal state vector YCZT and the temperature development change characteristic vector ZS according to the following formula, and calculate the abnormal state level value YCZT lev : YCZT lev =YCZT·ZS; Step 4: Classification of abnormal temperature levels According to the safety risks of ships carrying dangerous goods, the temperature abnormality level WDYCZT of ships carrying dangerous goods is divided into four levels from severe to mild, namely level 1: emergency linkage disposal level, level 2: navigation emergency organization level, level 3: enterprise remote supervision level, level 4: ship self-inspection level; Three safety thresholds are set, namely: temperature anomaly level 1 threshold LEV1, temperature anomaly level 2 threshold LEV2, and temperature anomaly level 3 threshold LEV3, and LEV3 < LEV2 < LEV1. The temperature anomaly level WDYCZT is determined according to the following judgment rules: When 0<YCZT lev When ≤LEV3, the abnormal temperature level WDYCZT is level 4; When LEV3<YCZT lev When ≤LEV2, the abnormal temperature state level WDYCZT is level 3; When LEV2<YCZT lev When ≤LEV1, the abnormal temperature level WDYCZT is level 2; When LEV1<YCZT lev When , the abnormal temperature level WDYCZT is level one.

Images