Loading arm safety control system and method for LNG tank car

Abstract

The invention discloses a loading arm safety control system and method for an LNG tank lorry, and the system comprises a safety monitoring device which is used for collecting various feedback information in real time, and the feedback information is used for monitoring the environment of a loading yard, the motion state of a loading arm and the occurrence condition of a dangerous event in the whole loading process from the entering of the tank lorry to the completion of the loading operation; the feedback information is sent to the industrial personal computer; and the industrial personal computer is used for carrying out omnibearing safety monitoring according to the feedback information and sending a loading arm braking instruction and / or an early warning prompt when an abnormal event is detected so as to carry out safety auxiliary control on the loading arm. According to the invention, the occurrence of accidental risks in the whole loading process can be effectively prevented, response measures are formed, and the operation safety in the whole loading process is ensured.

Description

Technical Field

[0001] This invention relates to the field of oil and gas storage and transportation safety technology, and in particular to a safety control system and method for loading booms of LNG tank trucks. Background Technology

[0002] LNG (liquefied natural gas, primarily composed of methane), as a clean energy source, is loaded onto LNG tank trucks at LNG receiving terminals and LNG liquefaction plants. If an LNG leak occurs, static electricity can accumulate in the tank truck due to factors such as electrostatic discharge from the human body or poor grounding, potentially triggering an electrostatic explosion. Furthermore, in China, LNG loading stations require two to three people to manually push the loading arm to the control box at the rear of the LNG tank truck and manually connect the gas and liquid phase arms to the corresponding gas and liquid phase interfaces on the tank truck. This loading process typically takes 30-60 minutes. During loading, on-site operators rely on experience to monitor for leaks. This loading process and monitoring method severely impact loading efficiency and pose significant safety hazards.

[0003] In an existing patent document (publication number CN111637361A), an automated loading and unloading device based on cryogenic skid mounting is provided. This solution replaces the original manual valve with a pneumatic breakaway valve. The breakaway valve provides a nitrogen conversion valve to quickly realize the valve's action, thereby reducing the workload of the operator and making it convenient to close the valve. This achieves automated loading and unloading without manual operation of all valves. However, it does not consider the impact of the loading yard environment, the movement state of the loading arm, and the occurrence of dangerous events on the overall loading process.

[0004] The existing patent document (publication number CN214744981U) provides an intelligent LNG tanker loading and unloading arm. This solution is used to automate the loading and unloading process of tankers, but it does not take into account the impact of the loading yard environment, the movement state of the loading arm, and the occurrence of dangerous events on the overall loading process.

[0005] In an existing patent document (publication number CN211315763U), a cryogenic fluid loading and unloading arm is provided. This solution effectively solves the problem of the loading and unloading arm naturally drooping due to gravity during loading and unloading docking by setting an anti-instability device. However, it does not consider the impact of the loading yard environment, the movement state of the loading arm, and the occurrence of dangerous events on the overall loading process.

[0006] Therefore, existing technical solutions do not consider the impact of loading yard environment, loading arm movement status and dangerous events on the overall loading process, resulting in low LNG loading efficiency and poor safety and convenience of loading operations.

[0007] In summary, there is a need in the existing technology to provide a solution for comprehensive safety monitoring during loading operations of a loading arm. Summary of the Invention

[0008] The purpose of this invention is to provide a solution for comprehensive safety monitoring of LNG loading operations, thereby solving the problems of low LNG loading efficiency and poor safety and convenience in the prior art.

[0009] To address the aforementioned technical problems, this invention provides a loading arm safety control system for LNG tank trucks. The loading arm safety control system includes: a safety monitoring device, which collects in real-time feedback information regarding the loading yard environment, loading arm movement status, and occurrence of hazardous events throughout the entire loading process, from the tank truck's arrival to the completion of the loading operation, and sends the feedback information to an industrial control computer; the industrial control computer performs comprehensive safety monitoring based on the feedback information and issues loading arm braking commands and / or warning prompts when an abnormal event is detected, thereby providing auxiliary safety control for the loading arm.

[0010] Preferably, the safety monitoring device includes: a loading arm motion feedback and control module, which receives the connection port position parameters of the tanker truck and automatically controls the loading arm of the loading skid to move to the pipeline connection port of the LNG tanker truck using the connection port position parameters as the target set value, wherein the pulse current signal representing the movement position of each joint is fed back and output; and a loading process intelligent identification module, which collects images of the dangerous areas of the loading operation in real time during the overall loading process, performs image processing, and outputs the image processing results as feedback information.

[0011] Preferably, the loading arm motion feedback and control module includes: at least one motor disposed at each joint of the loading arm for operation under the action of a motor control signal; an encoder disposed in the motor for acquiring pulse current signals when the corresponding joint rotates, so that the industrial control computer obtains feedback joint motion position information based on the pulse current signals; limit switches for verifying the motion position of each joint; and a motor control unit for generating motor control signals for each joint based on the target set value and in combination with the verified actual position of each joint, so as to perform closed-loop feedback adjustment of the motion parameters of the motor.

[0012] Preferably, the motor control unit is further configured to adjust the motor operating parameters according to the following steps: determining the actual target position after integrating the actual positions of each joint based on the pulse current signal representing the verified joint movement position; performing position correction calculation based on the actual target position and the target set value to obtain a position control signal for adjusting towards the target set value; performing speed correction calculation based on the position control signal and the speed corresponding to the pulse current signal to obtain a speed control signal for adjusting towards the target set value; and performing current correction calculation based on the speed control signal and the output current of each motor to obtain a motor control signal for adjusting towards the target set value, so as to use the motor control signal to adjust the rotational torque of the corresponding motor.

[0013] Preferably, the intelligent recognition module for the loading process includes: a binocular camera, which has corresponding cameras installed on the top and side of the canopy at the entrance of the loading yard, respectively, and the binocular camera is used to collect images containing all information in the dangerous area of ​​the loading operation in real time; an image processing unit, which is used to perform differential processing, binary processing, closing operation and contour recognition on the continuously acquired loading operation images in sequence to obtain the image processing result of each image; and a multi-parameter sensor installed at the end of the loading arm, which is used to collect various sensing signals in real time, including displacement sensing signals, ultrasonic sensing signals and image sensing signals.

[0014] Preferably, the industrial control computer is also used to monitor the overall loading process according to the following procedure: based on the real-time acquired loading operation images and feedback pulse current signals, and combined with the dynamic pressure data from the purging system and the dynamic temperature data from the loading pre-cooling system, the computer monitors the sequential completion of each sub-process in the overall loading process. The sub-processes include: tank truck entry, static grounding after vehicle entry, loading arm movement control and positioning, initial nitrogen purging, nitrogen purging, loading pre-cooling, loading, secondary nitrogen purging, and loading arm return.

[0015] Preferably, the industrial control computer is further configured to detect hazardous events during the overall loading process according to the following steps: converting the feedback pulse current signal into position feedback information, and performing information fusion based on the image processing results, the position feedback information, and various sensor signals from the intelligent identification module of the loading process to determine the relative positional relationship and motion trend of the gas phase arm and the liquid phase arm, as well as the obstacle classification results in the displacement path of the loading arm; determining whether there is a collision between the gas / liquid phase arm and an obstacle on the movement path of the loading arm, or an intrusion of non-operating personnel or irrelevant objects into the hazardous area of ​​the loading operation, and thus issuing a braking command for the loading arm when a collision risk between the gas / liquid phase arm and / or an obstacle intrusion into the operation area is detected.

[0016] Preferably, the safety monitoring device further includes: a volatile medium leakage monitoring module, which is used to monitor the characteristic information of each monitoring point by setting different monitoring points in the loading arm and tank car. The industrial control computer is also used to determine the abnormal characteristics of the corresponding monitoring point based on the characteristic information of different monitoring points, so as to determine whether a medium leakage event has occurred in the loading yard, so as to issue a loading arm braking command when a medium leakage occurs.

[0017] Preferably, the volatile medium leakage monitoring module includes: an airtightness monitoring probe installed at the bottom of the canopy at the entrance of the loading yard, the airtightness monitoring probe covering all monitoring points, wherein the airtightness monitoring probe includes: an infrared detection device, a thermal imaging device, a temperature monitor and a combustible gas monitor.

[0018] Preferably, the safety monitoring device further includes: a fault diagnosis module for key components of the loading arm, which is used to monitor the status characteristics of different key components installed in the loading arm and the tanker. The industrial control computer is also used to determine the abnormal operating status of the corresponding key components based on the status characteristics of different key components, thereby determining whether abnormal motor operation, valve body blockage and leakage, and loading arm wear and loosening faults have occurred, so as to issue a loading arm braking command when any one or more of these faults occur.

[0019] Preferably, the abnormal operating states include, but are not limited to: current, voltage, temperature, vibration, and flow rate, and the key components include, but are not limited to: valves of the loading arm, valve instruments of the loading arm, and motors.

[0020] Preferably, the industrial control computer is also interlocked with the human body electrostatic grounding detection system and the tank truck electrostatic grounding detection system; the industrial control computer is also used to monitor the first electrostatic information in the loading yard and the second electrostatic information carried by the loading and unloading personnel, and to issue an early warning when the first electrostatic information is greater than a first preset value and / or the second electrostatic information is greater than a second preset value.

[0021] On the other hand, embodiments of the present invention also provide a safety control method for a loading arm of an LNG tanker truck. The loading arm safety control method is implemented using the loading arm control system described above. The loading arm safety control method includes: a safety monitoring device collecting feedback information in real time to monitor the loading yard environment, loading arm movement status, and occurrence of dangerous events during the entire loading process from the tanker truck's arrival to the completion of the loading operation, and sending the feedback information to an industrial control computer; the industrial control computer performs comprehensive safety monitoring based on the feedback information, and issues a loading arm braking command and / or warning prompt when an abnormal event is detected, so as to provide safety auxiliary control for the loading arm.

[0022] Compared with the prior art, one or more embodiments of the above solutions may have the following advantages or beneficial effects:

[0023] This invention proposes a safety control method for the loading arm of LNG tank trucks. The system and method automatically move the loading arm to the pipeline connection port of the LNG tank truck, improving the loading efficiency and convenience of LNG tank trucks. It also effectively prevents unexpected risks during the overall loading process and establishes corresponding countermeasures, thereby ensuring the safety and convenience of the loading operation, improving the automation and safety levels of the loading site, and further enhancing the operational efficiency of LNG receiving stations or liquefaction plants.

[0024] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims, and drawings. Attached Figure Description

[0025] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0026] Figure 1 This is a schematic diagram of the overall structure of the loading arm safety control system for LNG tank trucks according to an embodiment of this application.

[0027] Figure 2 This is a schematic diagram of the specific structure of the loading arm motion feedback and control module in the loading arm safety control system for LNG tank trucks according to an embodiment of this application.

[0028] Figure 3 This is a schematic diagram illustrating the implementation process of the intelligent identification module for the loading process in the loading arm safety control system for LNG tank trucks, as described in an embodiment of this application.

[0029] Figure 4 This is a schematic flowchart illustrating the image processing unit in the loading arm safety control system for LNG tank trucks according to an embodiment of this application.

[0030] Figure 5 This is a schematic diagram illustrating the principle of using a volatile medium leakage monitoring module to monitor leakage point characteristic information in the loading arm safety control system for LNG tank trucks according to an embodiment of this application.

[0031] Figure 6 This is a schematic diagram illustrating the principle of using a fault diagnosis module for key components of the loading arm to monitor the status characteristics of different components in the safety control system for the loading arm of an LNG tanker according to an embodiment of this application.

[0032] Figure 7 This is a schematic diagram illustrating the principle of adjusting motor operating parameters using a motor control unit in the safety control system for the loading arm of an LNG tanker according to an embodiment of this application.

[0033] Figure 8 This is a schematic diagram illustrating the specific process of using an industrial control computer to monitor the overall loading process in the loading arm safety control system for LNG tank trucks, as described in an embodiment of this application.

[0034] Figure 9 This is a schematic diagram of the overall steps of the loading arm safety control method for LNG tank trucks according to an embodiment of this application. Detailed Implementation

[0035] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings and examples, so that the process of how the present invention uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. It should be noted that, as long as there is no conflict, the various embodiments and features in the various embodiments of the present invention can be combined with each other, and the resulting technical solutions are all within the protection scope of the present invention.

[0036] Furthermore, the steps illustrated in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Also, although a logical order is shown in the flowcharts, in some cases the steps shown or described may be performed in a different order than that shown here.

[0037] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms “a” and “an” as used herein are also intended to include the plural. It should also be understood that the terms “comprising” and / or “including” as used herein specify the presence of the stated features, integers, steps, operations, units, and / or components, without excluding the presence or addition of one or more other features, integers, steps, operations, units, components, and / or combinations thereof.

[0038] LNG (liquefied natural gas, primarily composed of methane), as a clean energy source, is loaded onto LNG tank trucks at LNG receiving terminals and LNG liquefaction plants. If an LNG leak occurs, static electricity can accumulate in the tank truck due to factors such as electrostatic discharge from the human body or poor grounding, potentially triggering an electrostatic explosion. Furthermore, in China, LNG loading stations require two to three people to manually push the loading arm to the control box at the rear of the LNG tank truck and manually connect the gas and liquid phase arms to the corresponding gas and liquid phase interfaces on the tank truck. This loading process typically takes 30-60 minutes. During loading, on-site operators rely on experience to monitor for leaks. This loading process and monitoring method severely impact loading efficiency and pose significant safety hazards.

[0039] In an existing patent document (publication number CN111637361A), an automated loading and unloading device based on cryogenic skid mounting is provided. This solution replaces the original manual valve with a pneumatic breakaway valve. The breakaway valve provides a nitrogen conversion valve to quickly realize the valve's action, thereby reducing the workload of the operator and making it convenient to close the valve. This achieves automated loading and unloading without manual operation of all valves. However, it does not consider the impact of the loading yard environment, the movement state of the loading arm, and the occurrence of dangerous events on the overall loading process.

[0040] The existing patent document (publication number CN214744981U) provides an intelligent LNG tanker loading and unloading arm. This solution is used to automate the loading and unloading process of tankers, but it does not take into account the impact of the loading yard environment, the movement state of the loading arm, and the occurrence of dangerous events on the overall loading process.

[0041] In an existing patent document (publication number CN211315763U), a cryogenic fluid loading and unloading arm is provided. This solution effectively solves the problem of the loading and unloading arm naturally drooping due to gravity during loading and unloading docking by setting an anti-instability device. However, it does not consider the impact of the loading yard environment, the movement state of the loading arm, and the occurrence of dangerous events on the overall loading process.

[0042] Therefore, existing technical solutions do not consider the impact of loading yard environment, loading arm movement status and dangerous events on the overall loading process, resulting in low LNG loading efficiency and poor safety and convenience of loading operations.

[0043] In summary, the existing technology needs to provide a solution for safety monitoring during loading operations of a loading arm.

[0044] Example 1

[0045] Figure 1 This is a schematic diagram of the overall structure of the loading boom safety control system for LNG tank trucks according to an embodiment of this application. See below for reference. Figure 1 The specific structure of the loading arm safety control system for LNG tank trucks (hereinafter referred to as the "loading arm safety control system") described in the embodiments of the present invention will be explained.

[0046] like Figure 1 As shown, the loading arm safety control system includes: a safety monitoring device 1 and an industrial control computer 2.

[0047] The safety monitoring device 1 is configured to collect feedback information in real time on the loading yard environment, loading arm movement status and occurrence of dangerous events during the entire loading process from the arrival of the tanker truck to the completion of the loading operation, and send the feedback information to the industrial control computer 2.

[0048] The industrial control computer 2 is configured to perform comprehensive safety monitoring based on various feedback information, and issue loading arm braking commands and / or warning prompts when abnormal events are detected, so as to provide safety auxiliary control for the loading arm.

[0049] In one embodiment, the safety monitoring device 1 includes: a loading arm motion feedback and control module 3 and a loading process intelligent identification module 4.

[0050] The loading arm motion feedback and control module 3 is configured to receive the connection port position parameters of the tanker truck and automatically control the loading arm of the loading skid to move to the pipeline connection port of the LNG tanker truck using the connection port position parameters as the target set value. The loading arm motion feedback and control module 3 is also configured to output pulse current signals representing the motion position information of each joint within the loading arm.

[0051] The intelligent identification module 4 for loading process is configured to collect images of dangerous areas in the loading operation during the entire loading process in real time, and perform image processing to output the image processing results as feedback information.

[0052] Furthermore, the loading arm motion feedback and control module 3 includes: at least one motor, an encoder 6 installed in the motor 5, a limit switch 7, and a motor control unit 8.

[0053] At least one motor is installed at each joint of the loading arm, meaning each joint is equipped with a corresponding motor. Motor 5 is configured to operate under the action of motor control signals.

[0054] The encoder 6 is configured to acquire pulse current signals when the corresponding joint rotates, so that the industrial computer 2 can obtain feedback joint motion position information based on the pulse current signals.

[0055] Limit switch 7 is configured to verify the movement position of each joint.

[0056] The motor control unit 8 is configured to generate motor control signals for each joint based on the target set value and the actual position of each joint after verification, so as to perform closed-loop feedback adjustment of the motion parameters of the motor 5.

[0057] In this embodiment, reference Figure 2The motors in the loading arm motion feedback and control module 3 may include at least one motor located at each joint of the gas phase arm and at least one motor located at each joint of the liquid phase arm. Each joint is equipped with a corresponding motor, and each motor has an encoder internally. In this embodiment, the at least one motor located at each joint of the gas phase arm is identified as motor 1-1, motor 1-2, and motor 1-3. The at least one motor located at each joint of the liquid phase arm is identified as motor 2-1, motor 2-2, and motor 2-3.

[0058] Specifically, encoder 6 is a sensor used to measure the rotation angle of a joint, typically mounted on the joint to accurately measure its position and movement. Encoder 6 acquires pulsed current signals as the joint rotates; these pulsed current signals can be used to calculate the position and movement of the end effector, thus enabling the industrial computer 2 to obtain feedback joint movement position information based on the pulsed current signals. Optionally, encoder 6 can be a position encoder for the loading arm assist unit.

[0059] Optionally, after prolonged use, the loading arm may deform or the motor control gears may become inaccurate, requiring zero-point calibration of encoder 6. In this case, encoder 6 needs to be connected to a computer and calibrated using encoder-related software. It is important to note that zero-point calibration of encoder 6 should be performed after installation, and during use, avoid rotating the loading arm beyond the encoder's measurement range to prevent affecting the encoder's measurement accuracy.

[0060] Further, continue to refer to Figure 2 The loading arm motion feedback and control module 3 also includes at least one shut-off valve. This shut-off valve is used to control the connection status between the loading arm and the LNG tanker interface. Specifically, the at least one shut-off valve includes at least one shut-off valve located on the gas phase arm and at least one shut-off valve located on the liquid phase arm.

[0061] At least one shut-off valve installed on the gas phase arm includes a main shut-off valve (i.e., shut-off valve 1-1) installed at the gas phase arm port and branch shut-off valves (shut-off valves 1-2, 1-3, and 1-4) installed between motors 1-2 and 1-3. At least one shut-off valve installed on the liquid phase arm includes a main shut-off valve (i.e., shut-off valve 2-1) installed at the liquid phase arm port and branch shut-off valves (shut-off valves 2-2, 2-3, and 2-4) installed between motors 2-2 and 2-3.

[0062] Furthermore, the intelligent recognition module 4 for the loading process includes: a binocular camera 10, an image processing unit 11, and a multi-parameter sensor 9 disposed at the end of the loading arm.

[0063] The binocular camera 10 is equipped with cameras on the top and sides of the canopy at the entrance of the loading yard. The binocular camera 10 is configured to acquire images containing all information within the hazardous area of ​​the loading operation in real time.

[0064] The image processing unit 11 is configured to sequentially perform differential processing, binary processing, closing operation and contour recognition on the continuously acquired loading operation images, thereby obtaining the image processing result of each image.

[0065] The multi-parameter sensor 9 is configured to acquire various sensing signals in real time. These sensing signals include: displacement sensing signals, ultrasonic sensing signals, and image sensing signals.

[0066] Specifically, refer to Figure 3 The implementation process of the intelligent identification module 4 during the loading process can be as follows: First, the loading process is planned, and the dangerous areas for loading operations are defined. Second, the pre-planned dangerous areas for loading operations are photographed by a binocular camera 10, and the images are processed by the image processing unit 11 to obtain the image processing results for each image. When an abnormal intrusion is detected based on the image processing results, the system can trigger an audible and visual alarm and display the alarm content. Then, the multi-parameter sensor 9 installed at the end of the loading arm collects data on the abnormal intrusion object in real time and feeds the results back to the working condition machine 2. When the working condition machine 2 confirms that the abnormal intrusion object is no longer present, the alarm is deactivated and the loading operation continues; otherwise, the loading operation is suspended. (Refer to...) Figure 4 The image recognition process includes sequentially performing difference processing, binary operation, closing operation, and contour recognition.

[0067] Optionally, the multi-parameter sensor 9 can be a sensor integrating a laser displacement sensor, an ultrasonic sensor, and an image sensor, capable of classifying and detecting the position of obstacles in the loading arm's displacement path. The laser displacement sensor has a small range but high accuracy, capable of detecting obstacles within a range of 80–500 mm with an accuracy of 0.1 mm, used for accurately detecting the distance to obstacles at the end of the loading arm when the loading arm is close to the tank truck body. The ultrasonic sensor has a large range, capable of detecting obstacles within a range of 300–8000 mm, used for roughly detecting the distance to obstacles at the end of the loading arm when the distance to the tank truck body is greater. The image sensor has a large field of view, performing visual detection of obstacles within its field of view, and working in conjunction with the ultrasonic and laser sensors to detect the spatial position of obstacles.

[0068] In one embodiment, the safety monitoring device 1 further includes a volatile medium leakage monitoring module.

[0069] The volatile medium leakage monitoring module is configured to monitor the characteristic information of each monitoring point by setting leakage monitoring points at different locations in the loading arm and tanker.

[0070] When the industrial control computer 2 works in conjunction with the volatile medium leakage monitoring device, the industrial control computer 2 is also configured to determine the abnormal characteristics of the corresponding monitoring points based on the characteristic information of different monitoring points, thereby determining whether a medium leakage event has occurred at the loading yard, so as to issue a loading arm braking command when a medium leakage occurs. The abnormal characteristics include, but are not limited to: the amount of leaked gas, whether the leaked gas contains flammable gas, abnormal temperature, etc.

[0071] Optionally, leakage monitoring points in different locations include, but are not limited to: pipe connections such as flanges and joints; valves such as shut-off valves; and connections between instruments and pipes.

[0072] Furthermore, the volatile medium leakage monitoring module includes an airtightness monitoring probe installed at the bottom of the canopy at the entrance of the loading yard. The airtightness monitoring probe can cover leakage monitoring points at all locations.

[0073] The airtightness monitoring probes include: infrared detection equipment, thermal imaging equipment, temperature monitoring instruments, and combustible gas monitoring instruments.

[0074] Specifically, the process of the volatile medium leakage monitoring device is as follows:

[0075] 1. Air tightness monitoring locations include, but are not limited to: flanges, joints, and pipe connections; valves such as shut-off valves; and connections between instruments and pipes.

[0076] 2.Reference Figure 5 The methods for monitoring gas tightness include, but are not limited to: (1) Infrared detection: Infrared radiation technology is used to detect leaked gas. Different types of gases and gases at different temperatures have different infrared radiation. Leakage points can be identified by detecting the radiation of specific types of gases. (2) Thermal imaging detection: The temperature of liquefied natural gas is usually between -160 degrees Celsius and -162 degrees Celsius. The temperature of meteorological natural gas also varies greatly with the outside atmospheric temperature. Therefore, thermal imaging technology can be used to detect whether there is a gas leak and identify the location of the leak point. (3) Temperature detection: Leakage points are identified by detecting the temperature difference between LNG and the outside atmosphere. When flammable liquids evaporate, they take away a lot of heat, making the regional temperature field gradient and time gradient more obvious, forming thermal image temperature gradient characteristics. By fusing and analyzing the information of easily leaking parts through thermal imager and visible light camera, and combining its image texture, contour features and thermal image temperature gradient, the leakage of volatile medium can be judged. (4) Combustible gas detection.

[0077] Alternatively, in order to better monitor whether a medium leak occurs during the loading operation, an acoustic sensor can be installed at the loading arm valve to determine whether a leak has occurred at the loading arm valve through acoustic frequency domain analysis. Alternatively, a gas sensor can be installed at the loading arm valve to determine whether a leak has occurred at the loading arm valve through gas detection and analysis.

[0078] In one embodiment, the safety monitoring device 1 further includes a fault diagnosis module for key components of the loading arm.

[0079] The critical component fault diagnosis module for the loading boom is configured to monitor the status characteristics of various critical components located within the loading boom and tanker truck. These critical components include, but are not limited to: valves in the loading boom's valve body, valve body instruments in the loading boom, and motors.

[0080] When the industrial control computer 2 works in conjunction with the fault diagnosis module for key components of the loading arm, the industrial control computer 2 is also configured to determine the abnormal operating status of the corresponding key components based on the state characteristics of different key components. This allows it to determine whether abnormal motor operation, valve body blockage and leakage, or loading arm wear and loosening faults have occurred. In the event of any one or more of these faults, a loading arm braking command will be issued. These abnormal operating statuses include, but are not limited to, current, voltage, temperature, vibration, and flow rate.

[0081] Optionally, fault diagnosis for the motor includes: current and voltage monitoring, encoder feedback monitoring, vibration status monitoring, and infrared thermal imaging monitoring. Fault diagnosis for valve body instruments and valves includes: flow monitoring, pressure monitoring, temperature monitoring, valve position feedback, valve body status monitoring, valve body sound analysis, and valve body leakage detection.

[0082] Specifically, refer to Figure 6 (a) The specific process of fault diagnosis of the motor by the fault diagnosis module of the loading arm key component is as follows:

[0083] (1) Current and voltage monitoring. Monitoring the input current and voltage of the motor can detect electrical problems such as short circuits, open circuits, and cable connection problems. Abnormal current or voltage waveforms may be signs of a fault.

[0084] (2) Encoder feedback. The encoder inside the motor provides position feedback. Monitoring the encoder feedback signal can detect motion control problems of the motor, such as step loss, position drift, and encoder failure.

[0085] (3) Vibration analysis. Vibration sensors can be used to monitor the vibration of the motor. Abnormal vibration may indicate mechanical problems, such as imbalance, bearing wear, or mechanical component failure.

[0086] (4) Temperature monitoring: Continuous monitoring of the motor temperature can detect overheating problems, which may be signs of insulation problems, insufficient cooling, or abnormal motor load. Infrared imaging technology can be used to monitor the temperature distribution of the motor to identify possible overheating or uneven heating problems.

[0087] Furthermore, the fault diagnosis module for key components of the loading arm can determine the motor's fault condition by analyzing motor control parameters and monitoring motor operating status. Monitoring the motor's operating status, such as speed, position, and torque, can detect abnormal behavior or performance problems; analyzing the motor's control parameters, such as PID parameters (proportional-integral-derivative), can detect problems with the control system, such as excessively long response time or instability.

[0088] Specifically, refer to Figure 6 (b) The specific process of fault diagnosis of valve body valves and valve body instruments by the fault diagnosis module of the loading arm key components is as follows:

[0089] (1) Flow, pressure and temperature monitoring: Monitoring the flow, pressure and temperature data of fluids around the valve body and instruments can help detect abnormal operation in the system, such as blockage, leakage or overload.

[0090] (2) Valve position feedback: The position of the valve can be monitored using a position sensor to ensure that it operates as expected. If the position is incorrect, adjustments or maintenance operations can be performed.

[0091] (3) Vibration analysis: Use vibration sensors to monitor the vibration of the valve. If abnormal vibration occurs, it indicates that there is a mechanical problem with the valve body, such as bearing wear or valve disc loosening.

[0092] In one embodiment, the industrial computer 2 is also interlocked with the human body electrostatic grounding detection system and the tank truck electrostatic grounding detection system.

[0093] The industrial control computer 2 is also configured to monitor the first static electricity information in the loading yard and the second static electricity information carried by the loading and unloading personnel. When the first static electricity information is greater than the first preset value and / or the second static electricity information is greater than the second preset value, an early warning reminder will be issued.

[0094] The specific values ​​of the first and second preset values ​​are not limited and can be reasonably selected according to actual application needs.

[0095] Specifically, the industrial control computer 2 monitors the static electricity levels of personnel during LNG loading and unloading operations. It issues alarms when static electricity levels are high and may even automatically shut down the loading arm pipeline and the LNG handling pipelines to the liquid / gas phase to prevent electrostatic discharge. Through human static electricity grounding monitoring, tank truck static electricity grounding detection system configuration interlocks, and a fine water atomization system at the loading and unloading site, it proactively controls static electricity on personnel in the loading and unloading area. This process can eliminate potential accidents caused by potentially charged human bodies inducing leakage, flammable gas combustion, and explosion, ensuring the personal safety of loading and unloading personnel.

[0096] Example 2

[0097] Based on the above embodiment one, the implementation process of the present invention of adjusting the motor operating parameters using a motor control unit will be described in detail below. Figure 7 This is a schematic diagram illustrating the principle of adjusting motor operating parameters using a motor control unit in the safety control system for the loading arm of an LNG tanker truck, as described in an embodiment of this application. Figure 7 As shown, the motor control unit will adjust the motor operating parameters according to the following steps:

[0098] S1, based on the pulse current signals representing the verified joint movement positions, determine the actual target position after integrating the actual positions of each joint.

[0099] S2, based on the actual target position and the target set value, performs position correction calculations to obtain a position control signal used to adjust to the target set value.

[0100] S3, based on the speeds corresponding to the position control signal and the pulse current signal, performs speed correction calculations to obtain the speed control signal used to adjust to the target setting value.

[0101] S4. Based on the speed control signal and the output current of each motor, current correction calculation is performed to obtain the motor control signal used to adjust to the target set value, so as to use the motor control signal to adjust the rotational torque of the corresponding motor.

[0102] In this embodiment, firstly, the movement position of each joint is obtained by analyzing the pulse current signal, and then the movement position of each joint is verified by using limit switches. This process is equivalent to determining the actual target position after integrating the actual positions of each joint.

[0103] In this embodiment, the target setting value is obtained based on the connection port position parameters of the tank truck, and then the deviation between the actual target position after the integration of each joint and the target setting value is corrected and calculated so that the loading arm can reach the target setting position during the movement of the next stage.

[0104] During position adjustment, a position control signal for adjusting the target setting is obtained by combining the actual target position and the target set value with the position loop. Then, based on the position control signal and the speed corresponding to the pulse current signal at that time, a speed control signal for adjusting towards the target setting value is obtained by combining the speed control signal and the output current of each motor with the current loop. Finally, a motor control signal is obtained by combining the speed control signal and the output current of each motor with the current loop. The rotational torque of the corresponding motor is adjusted by clicking the control signal, thereby compensating for the position adjustment.

[0105] Specifically, the motor control unit achieves precise control and self-calibration of the loading arm displacement through closed-loop self-feedback. This self-feedback is implemented using a three-loop control algorithm, consisting of a current loop, a speed loop, and a position loop from the inside out. The outermost loop, the position loop, has its setpoint derived from an external command, i.e., the actual target position. The setpoints for the other two control loops are derived from the calculation results of the previous control loop. The principle of the three-loop control algorithm is as follows: Figure 7 As shown.

[0106] Furthermore, the output current of each motor is converted into corresponding decimal data by an AD converter, and then enters the current loop for calculation. The current loop mainly controls the rotational torque of the motor, which is the most basic guarantee for the motor's response speed to command pulses and can significantly improve its closed-loop performance.

[0107] Example 3

[0108] Based on the above embodiments one and two, the implementation functions of the industrial control computer of the present invention will be specifically described below.

[0109] In one embodiment, reference Figure 8 The industrial control computer 2 is also used to monitor the overall loading process according to the following procedure:

[0110] Based on real-time acquired images of the loading operation and feedback pulse current signals, combined with dynamic pressure data from the purging system and dynamic temperature data from the loading pre-cooling system, the sequential completion status of each sub-process in the overall loading process is monitored.

[0111] The sub-processes include: tanker truck arrival, static grounding after vehicle arrival, loading arm movement control and positioning, initial nitrogen purging, nitrogen blowing, loading pre-cooling, loading, secondary nitrogen purging, and loading arm return to position.

[0112] In this embodiment, reference Figure 8 The industrial control computer 2 analyzes the real-time collected images of the loading operation to determine whether the tanker truck entry process has been completed. If so, the loading arm safety control system is in active mode; otherwise, it remains in sleep mode.

[0113] After the tanker truck enters the site, the industrial control computer 2 analyzes the real-time collected images of the loading operation to determine whether the tanker truck has entered the designated position. If so, the industrial control computer 2 analyzes the real-time collected images of the loading operation to determine whether the static grounding step after the vehicle enters the site has been completed. If not, the loading arm safety control system remains in active mode.

[0114] After the industrial control computer 2 determines that the electrostatic grounding link after the vehicle enters the site has been completed, it determines whether the loading arm movement control and positioning link has been completed based on the feedback pulse current signal. If the electrostatic grounding link after the vehicle enters the site has not been completed, the loading arm safety control system remains in active mode.

[0115] Once the loading arm movement control is completed and in position, the shut-off valve opens, and a limit switch detects whether the valve is open. When the limit switch detects that the shut-off valve is open, the initial nitrogen purging process begins; when the limit switch detects that the shut-off valve is not open, the valve remains open.

[0116] During the initial nitrogen purging process, the industrial control computer 2 monitors the dynamic pressure data of the purging system in real time. When the dynamic pressure data of the purging system is greater than or equal to a first preset value, the initial nitrogen purging process is considered complete, and the process proceeds to the nitrogen purging stage. When the dynamic pressure data of the purging system is less than the first preset value, the initial nitrogen purging process continues. Optionally, the first preset value can be 0.4.

[0117] During the nitrogen purging process, the industrial control computer 2 monitors the dynamic pressure data of the purging system in real time. When the dynamic pressure data of the purging system is greater than or equal to the second preset value, the nitrogen purging process is considered complete. When the dynamic pressure data of the purging system is less than the second preset value, the nitrogen purging process continues.

[0118] After the nitrogen purging process is completed, the industrial control computer 2 analyzes the dynamic temperature data of the vehicle loading precooling system in real time to determine whether the vehicle loading precooling process is complete. If so, the vehicle loading process begins; otherwise, the vehicle loading precooling process continues.

[0119] During the loading process, the industrial control computer 2 monitors the loading flow rate. When the loading flow rate is greater than or equal to the preset flow rate value, it indicates that the loading process is completed. When the loading flow rate is less than the preset flow rate value, the loading process continues.

[0120] After the loading process is completed, a secondary nitrogen purging process is carried out. The industrial control computer 2 determines whether the secondary nitrogen purging process has been completed based on the dynamic pressure data of the purging system in real time. If it is completed, the shut-off valve is closed; otherwise, the secondary nitrogen purging process continues.

[0121] After the secondary nitrogen purging process is completed, the limit switch is used to check whether the shut-off valve is working. If it is, the loading arm returns to its original position; otherwise, the shut-off valve is put into operation.

[0122] After the shut-off valve operates, the industrial control computer 2 analyzes the real-time acquired loading operation images to determine whether the loading arm return step has been completed. If yes, the entire loading process is completed; otherwise, the loading arm return step continues.

[0123] Optionally, an endoscope camera can be installed at the end of the loading arm. This endoscope camera has a small field of view and can monitor the completion of loading and unloading tasks in real time.

[0124] In one embodiment, the industrial computer 2 is also used to monitor hazardous events during the overall vehicle assembly process according to the following steps:

[0125] A1 converts the feedback pulse current signal into position feedback information, and performs information fusion based on the image processing results, position feedback information, and various sensor signals from the intelligent identification module 4 of the loading process to determine the relative positional relationship and motion trend of the gas phase arm and the liquid phase arm, as well as the obstacle classification results in the displacement path of the loading arm.

[0126] A2 determines whether there is a collision between the gas-liquid phase arm and an obstacle on the movement path of the loading arm, or whether non-operating personnel or unrelated objects have entered the dangerous area of ​​the loading operation. When a collision risk between the gas-liquid phase arm and / or an obstacle has entered the operating area is detected, a loading arm braking command is issued.

[0127] In this embodiment, the absolute positions of the gas phase arm and liquid phase arm of the loading arm are obtained by converting the feedback pulse current signal into position feedback information. Then, based on the image processing results, the relative positional relationship and motion trend of the liquid and gas phase arms are determined in real time. The absolute positions and motion trends of the gas and liquid phase arms are used to determine whether there is a collision risk. When the absolute positions of the gas and liquid phase arms overlap, it indicates a collision, and a braking command is issued to the loading arm. Furthermore, the real-time position of obstacles can be obtained using multi-parameter sensors, and analysis based on the real-time position of the obstacles and the absolute positions of the gas and liquid phase arms is performed to determine whether the gas and liquid phase arms will collide with obstacles on the movement path of the loading arm.

[0128] In this embodiment, the image information collected by the binocular camera 10 can be used to determine whether there are non-operating personnel or irrelevant objects intruding into the dangerous area of ​​the loading operation. When non-operating personnel or irrelevant objects intrude into the dangerous area of ​​the loading operation, a loading arm braking command is issued.

[0129] Among them, irrelevant objects refer to objects that may pose safety hazards to the LNG loading operation, such as objects carrying static electricity.

[0130] Example 4

[0131] Based on the loading arm safety control system provided in Embodiments 1-3 above, this invention also provides a loading arm safety control method for LNG tank trucks. This loading arm safety control method utilizes the loading arm safety control system described above.

[0132] Figure 9 This is a schematic diagram illustrating the overall steps of a loading boom safety control method for LNG tank trucks, according to an embodiment of this application. Figure 9 As shown, the loading arm safety control method according to an embodiment of the present invention includes the following steps:

[0133] In step S910, the safety monitoring device 1 collects feedback information in real time on the loading yard environment, loading arm movement status, and occurrence of dangerous events during the entire loading process from the arrival of the tanker truck to the completion of the loading operation, and sends the feedback information to the industrial control computer 2.

[0134] In step S920, the industrial control computer 2 performs comprehensive safety monitoring based on various feedback information, and issues a loading arm braking command and / or warning prompt when an abnormal event is detected, so as to provide safety auxiliary control for the loading arm.

[0135] This invention proposes a safety control system and method for the loading arm of LNG tank trucks. This system and method automatically moves the loading arm to the pipeline connection port of the LNG tank truck, improving the collision prevention efficiency and convenience of the LNG tank truck. Furthermore, it effectively prevents unexpected risks during the overall loading process and establishes corresponding countermeasures, thereby ensuring the safety and convenience of the loading operation. Simultaneously, it improves the automation and safety levels at the loading site, further enhancing the operational efficiency of LNG receiving terminals or liquefaction plants.

[0136] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

[0137] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0138] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0139] It should be understood that the embodiments disclosed herein are not limited to the specific structures, processing steps, or materials disclosed herein, but should be extended to equivalent substitutions of these features as understood by those skilled in the art. It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.

[0140] The phrase "an embodiment" or "an embodiment" used in this specification means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Therefore, the phrase "an embodiment" or "an embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0141] While the embodiments disclosed in this invention are as described above, the content is merely for the purpose of facilitating understanding of the invention and is not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and changes in form and detail of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection of this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A safety control system for a loading boom of an LNG tanker truck, characterized in that, The loading arm safety control system includes: The safety monitoring device is used to collect feedback information in real time to monitor the loading yard environment, loading arm movement status and occurrence of dangerous events during the entire loading process from the arrival of the tanker truck to the completion of the loading operation, and sends the feedback information to the industrial control computer. The industrial control computer is used to perform comprehensive safety monitoring based on the feedback information, and to issue loading arm braking commands and / or warning prompts when abnormal events are detected, so as to provide safety auxiliary control for the loading arm.

2. The loading boom safety control system according to claim 1, characterized in that, The safety monitoring device includes: The loading arm motion feedback and control module is used to receive the connection port position parameters of the tanker truck and automatically control the loading arm of the loading skid to move to the pipeline connection port of the LNG tanker truck with the connection port position parameters as the target set value. The module also outputs the pulse current signal representing the movement position of each joint. The intelligent identification module for the loading process is used to collect images of dangerous areas in the loading operation in real time during the entire loading process, and to process the images and output the image processing results as feedback information.

3. The loading boom safety control system according to claim 2, characterized in that, The loading arm motion feedback and control module includes: At least one motor is provided at each joint of the loading arm for operation under the action of motor control signals; An encoder installed in the motor is used to collect pulse current signals when the corresponding joint rotates, so that the industrial control computer can obtain feedback joint motion position information based on the pulse current signals. Limit switches are used to verify the movement position of each joint; The motor control unit is used to generate motor control signals for each joint based on the target set value and the actual position of each joint after verification, so as to perform closed-loop feedback adjustment of the motion parameters of the motor.

4. The loading arm safety control system according to claim 3, characterized in that, The motor control unit is also used to adjust the motor operating parameters according to the following steps: Based on the pulse current signals representing the verified joint movement positions, the actual target position after integrating the actual positions of each joint is determined. Based on the actual target position and the target set value, position correction calculations are performed to obtain a position control signal for adjusting to the target set value. Based on the speeds corresponding to the position control signal and the pulse current signal, a speed correction calculation is performed to obtain a speed control signal for adjusting towards the target setting value; Based on the speed control signal and the output current of each motor, current correction calculation is performed to obtain a motor control signal for adjusting to the target set value, so as to use the motor control signal to adjust the rotational torque of the corresponding motor.

5. The loading boom safety control system according to any one of claims 2 to 4, characterized in that, The intelligent identification module for the loading process includes: A binocular camera is installed on the top and side of the canopy at the entrance of the loading yard. The binocular camera is used to collect images in real time containing all information in the dangerous area of ​​the loading operation. The image processing unit is used to sequentially perform differential processing, binary processing, closing operation and contour recognition on the continuously acquired loading operation images to obtain the image processing result of each image; A multi-parameter sensor is installed at the end of the loading arm to collect various sensing signals in real time, including displacement sensing signals, ultrasonic sensing signals, and image sensing signals.

6. The loading boom safety control system according to any one of claims 2 to 5, characterized in that, The industrial control computer is also used to monitor the overall loading process according to the following procedure: Based on real-time acquired images of the loading operation and feedback pulse current signals, combined with dynamic pressure data from the purging system and dynamic temperature data from the loading pre-cooling system, the sequential completion status of each sub-process in the overall loading process is monitored. The various sub-processes include: tanker truck arrival, static grounding after vehicle arrival, loading arm movement control and positioning, initial nitrogen purging, nitrogen blowing, loading pre-cooling, loading, secondary nitrogen purging, and loading arm return to position.

7. The loading boom safety control system according to claim 6, characterized in that, The industrial control computer is also used to detect hazardous events during the overall vehicle assembly process according to the following steps: The feedback pulse current signal is converted into position feedback information, and information fusion is performed based on the image processing results, the position feedback information and various sensor signals from the intelligent identification module of the loading process to determine the relative position relationship and motion trend of the gas phase arm and the liquid phase arm, as well as the obstacle classification results in the displacement path of the loading arm. It determines whether there is a collision between the gas-liquid phase arm and an obstacle on the movement path of the loading arm, or whether non-operating personnel or unrelated objects intrude into the dangerous area of ​​the loading operation. When a collision risk between the gas-liquid phase arm and / or an obstacle intrusion into the operation area is detected, a loading arm braking command is issued.

8. The loading boom safety control system according to any one of claims 2 to 7, characterized in that, The safety monitoring device also includes: A volatile medium leakage monitoring module is used to monitor characteristic information at various monitoring points set up inside the loading arm and tanker truck. The industrial control computer is also used to determine the abnormal characteristics of the corresponding monitoring points based on the characteristic information of different monitoring points, so as to determine whether a medium leakage event has occurred in the loading yard, so as to issue a loading arm braking command when a medium leakage occurs.

9. The loading arm safety control system according to claim 8, characterized in that, The volatile medium leakage monitoring module includes: an airtightness monitoring probe installed at the bottom of the canopy at the entrance of the loading yard, the airtightness monitoring probe covering all monitoring points, wherein, The airtightness monitoring probe includes: an infrared detection device, a thermal imaging device, a temperature monitoring instrument, and a combustible gas monitoring instrument.

10. The loading boom safety control system according to claim 8 or 9, characterized in that, The safety monitoring device also includes: A fault diagnosis module for key components of the loading arm is used to monitor the status characteristics of different key components installed in the loading arm and tanker truck. The industrial control computer is also used to determine the abnormal operating status of the corresponding key components based on the state characteristics of different key components, thereby determining whether abnormal motor operation, valve body blockage and leakage, and loading arm wear and loosening faults have occurred, so as to issue a loading arm braking command when any one or more of these faults occur.

11. The loading arm safety control system according to claim 12, characterized in that, The abnormal operating conditions include, but are not limited to: current, voltage, temperature, vibration, and flow rate. The key components include, but are not limited to: valves on the loading arm, valve instruments on the loading arm, and motors.

12. The loading boom safety control system according to any one of claims 1 to 11, characterized in that, The industrial control computer is also interlocked with the human body electrostatic grounding detection system and the tank truck electrostatic grounding detection system; The industrial control computer is also used to monitor the first static electricity information in the loading yard and the second static electricity information carried by the loading and unloading personnel. When the first static electricity information is greater than the first preset value and / or the second static electricity information is greater than the second preset value, an early warning reminder is issued.

13. A safety control method for a loading boom of an LNG tanker truck, characterized in that, The loading arm safety control method is implemented using the loading arm control system as described in any one of claims 1 to 12, wherein the loading arm safety control method includes: The safety monitoring device collects feedback information in real time to monitor the loading yard environment, loading arm movement status, and occurrence of dangerous events during the entire loading process from the arrival of the tanker truck to the completion of the loading operation, and sends the feedback information to the industrial control computer. The industrial control computer performs comprehensive safety monitoring based on the feedback information, and issues a loading arm braking command and / or warning prompt when an abnormal event is detected, so as to provide safety auxiliary control for the loading arm.

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