Electrostatic safety control system and method for an LNG loading / unloading site

Abstract

The application discloses an electrostatic safety control system and method for LNG loading and unloading sites, comprising: an electrostatic grounding self-detection device for detecting the electrostatic grounding state of an LNG tank car; a human body electrostatic monitoring device for real-time detection of the human body electrostatic potential of an operator; and a control device for diagnosing whether the tank car grounding detection is qualified according to the electrostatic grounding state, and diagnosing whether the electrostatic potential of the operator before and after the loading and unloading operation is in a safe state according to the human body electrostatic potential when the grounding detection is qualified, so as to output a response control strategy of interrupting the loading and unloading operation for an unsafe operation state. The application can effectively prevent the occurrence of the human body electrostatic overhigh and the equipment grounding bad condition in the LNG loading and unloading operation area, and form corresponding response measures, so as to ensure the safety of the on-site operation.

Description

TECHNICAL FIELD

[0001] The present application relates to the oil and gas storage and transportation safety technical field, and particularly to an electrostatic safety control system and method for an LNG loading and unloading site. BACKGROUND

[0002] LNG is a liquid fossil fuel after natural gas (main component methane) is compressed and cooled to its condensation point (-161.5℃) temperature, and has the characteristics of low temperature and easy vaporization. At present, as a clean energy, LNG is completed in the LNG receiving station and LNG liquefaction plant, and the transfer operation is completed by using the automobile tank car through land transportation. For pure methane, the minimum ignition energy is about 0.47mJ, and the explosion limit of methane in air is about 5% to 15%, among which the explosion is most violent at about 9.5%. Once LNG leaks and evaporates in large quantities, it may cause electrostatic accumulation of the tank car and induce spark discharge due to human body electrostatic discharge, poor grounding and other reasons, causing electrostatic explosion accidents in the LNG loading site such as the receiving station.

[0003] At present, the LNG loading site mainly eliminates the electrostatic of the tank car and the human body electrostatic by installing the tank car electrostatic grounding detector and the human body electrostatic eliminator near the loading pry. After the tank car is parked in the loading site, the tank car loading personnel (tank car driver and site management personnel) touch the human body electrostatic eliminator ball, open the tank car tail operating box door and clamp the tank car electrostatic grounding detector grounding clamp on the metal body of the tank car. However, in the existing patent documents CN201665524U, CN101830422A, CN101830422B and CN202769269U, when the disclosed low-temperature land fluid loading and unloading arm (ultra-low-temperature fluid loading and unloading arm) is used for tank car loading, the manual low-temperature valve is arranged on the liquid phase arm and the gas phase arm of the loading and unloading arm, and the flange connection is adopted at the end of the loading and unloading arm, which causes that the existing loading and unloading arm still needs to manually tighten 16 nuts of the liquid phase arm and the gas phase arm flanges before the LNG loading, so as to complete the docking of the tank car and the loading and unloading arm. When the loading is completed, the corresponding gas phase arm and liquid phase arm docking flanges are disassembled. Generally, the LNG loading time is 30-60 minutes, and the operator must monitor whether the loading arm and the LNG tank car leak in the site during the LNG loading. Therefore, if the leakage occurs at the sealing position of the universal joint, the valve and the flange of the loading arm, the corresponding valve on the tank car operating box and the loading and unloading arm must be manually closed on site, so as to prevent the continuous leakage of LNG in the tank car. Otherwise, if the leakage (or residual liquid leakage) occurs at the universal joint and the flange of the loading arm, the explosion space will be formed due to the rapid gasification of LNG, and the explosion will be caused when the static discharge spark occurs.

[0004] In addition, electrostatic discharge from the human body is a major ignition source in LNG loading areas. Due to the long loading time, it's inevitable that workers will accumulate static electricity due to prolonged on-site movement and monitoring of the loading process. Workers are required to wear anti-static shoes and clothing, but the quality of these items, frequent washing, or exceeding their service life can cause them to fail to meet safety standards. Especially during the dry winter months, it is crucial to prevent excessive static electricity in LNG work areas to avoid igniting leaked or vaporized methane gas. Existing patent document CN217736923U discloses an anti-static monitoring system for LNG refueling stations. This system primarily identifies workers entering the plant through video monitoring, detects their static electricity, and prompts them to manually touch a static eliminator to eliminate it. However, this requires a high degree of self-discipline from workers, making its implementation inherently risky.

[0005] In summary, traditional tank truck electrostatic grounding detectors are isolated systems and cannot be interlocked with the loading and unloading control system during LNG loading and unloading. This makes it difficult to completely eliminate the potential hazards of electrostatic discharge at LNG loading and unloading sites. Therefore, existing LNG loading and unloading sites lack a device that can monitor and eliminate static electricity from the human body during loading and unloading operations to address the risks of static electricity from the human body and / or electrostatic discharge from tank trucks during manual operations at LNG loading sites. Summary of the Invention

[0006] The purpose of this invention is to propose an electrostatic safety control scheme for LNG loading and unloading sites, so as to solve the risk of static electricity to human body and / or electrostatic discharge of tank trucks during manual operation at LNG loading sites in the prior art.

[0007] To address the aforementioned technical problems, this invention provides an electrostatic safety control system for LNG loading and unloading sites, comprising: an electrostatic grounding self-detection device for detecting the electrostatic grounding status of LNG tank trucks; a human electrostatic monitoring device for real-time detection of the electrostatic potential of workers; and a control device for diagnosing whether the tank truck grounding test is qualified based on the electrostatic grounding status, and, if the grounding test is qualified, diagnosing whether the electrostatic potential of workers is in a safe state before and after the loading and unloading operation based on the human electrostatic potential, thereby outputting a response control strategy to interrupt the loading and unloading operation in case of an unsafe operating state.

[0008] Preferably, the human body electrostatic monitoring device is implemented using a non-contact electric field sensor array, which is installed on a clamp or movable operating column via a connecting wire, and is located in the work area where the loading and unloading personnel are located.

[0009] Preferably, each non-contact electric field sensor is distributed at a position point of a terminal end of a loading arm in a loading pry in the LNG loading and unloading site, and a gas phase and liquid phase pipeline inlet at a rear end of a tank truck operation box; a universal joint and each valve in the loading arm; each valve in the tank truck operation box.

[0010] Preferably, the control device is further configured to dynamically diagnose the qualification of the tank truck grounding detection according to the real-time detected tank truck grounding capacitance value, grounding leakage resistance and grounding resistance, wherein when the tank truck grounding capacitance value fails to reach a preset capacitance threshold, or the grounding leakage resistance or the grounding resistance exceeds a corresponding preset resistance threshold, a first type of on-off control instruction for controlling the loading pry to be disconnected from the loading arm, and a second type of on-off control instruction for controlling the loading arm to be disconnected from the tank truck operation box are outputted, and a pre-warning is indicated; when the tank truck grounding capacitance value reaches or exceeds the preset capacitance threshold, and neither the grounding leakage resistance nor the grounding resistance exceeds the corresponding preset resistance threshold, indication information that the electrostatic grounding detection is qualified is outputted.

[0011] Preferably, the control device is further configured to, after obtaining the indication information that the electrostatic grounding detection is qualified, diagnose whether to start the loading and unloading operation according to the real-time detected human body electrostatic potential by using a preset electrostatic potential threshold, wherein when the human body electrostatic potential reaches or exceeds the preset electrostatic potential threshold, the first type of on-off control instruction for controlling the loading pry to be disconnected from the loading arm is outputted, and a pre-warning is indicated; when the human body electrostatic potential fails to reach the preset electrostatic potential threshold, indication information that the loading and unloading operation is allowed is outputted.

[0012] Preferably, the control device is further configured to, after obtaining the indication information that the loading and unloading operation is allowed, diagnose the qualified state of the electrostatic potential of an operator in the loading and unloading operation according to the real-time detected human body electrostatic potential by using the preset electrostatic potential threshold, wherein when the human body electrostatic potential reaches or exceeds the preset electrostatic potential threshold, the first type of on-off control instruction for controlling the loading pry to be disconnected from the loading arm is outputted, and a pre-warning is indicated; when the human body electrostatic potential fails to reach the preset electrostatic potential threshold, the first type of on-off control instruction for controlling the loading pry to be disconnected from the loading arm after the LNG loading and unloading is completed.

[0013] Preferably, the control device is further configured to compare the real-time detected static electric potential of the human body with a preset electric potential safety threshold, diagnose the qualified state of the static electric potential of the worker during the loading and unloading process, and the electric potential safety threshold is less than the static electric potential threshold, wherein when the human body static electric potential reaches or exceeds the preset electric potential safety threshold and does not exceed the preset static electric potential threshold, an abnormal alarm information is output to prompt the worker to stay away from the current work area.

[0014] Preferably, the first type of on-off control instruction is used to control the on-off state of a loading arm gas phase quick shut-off valve and a loading arm liquid phase quick shut-off valve used to connect the gas phase pipeline interface and the liquid phase pipeline interface on the loading sled to the gas phase arm and the liquid phase arm in the loading arm, respectively; and the second type of on-off control instruction is used to control the on-off state of a tank car gas phase pipeline emergency shut-off valve and a tank car liquid phase pipeline emergency shut-off valve used to connect the gas phase arm and the liquid phase arm in the loading arm to the gas phase pipeline interface and the liquid phase pipeline interface in the tank car operation box, respectively.

[0015] Preferably, the static electric safety control system further comprises a water droplet atomization device installed at the top of the loading station canopy or the loading sled, configured to actively atomize and humidify the current loading and unloading area under the control of a humidification instruction, so that the relative humidity of the loading and unloading area is maintained above a preset humidity threshold, wherein the humidification time is not less than 45 minutes and the preset humidity threshold is 50%, wherein the control device is further configured to generate the humidification instruction and send the humidification instruction to the water droplet atomization device when detecting that the static electric potential of the worker during the loading and unloading process is unqualified.

[0016] In another aspect, the embodiment of the present application provides a loading and unloading mechanism for an LNG loading and unloading site, comprising: the static electric safety control system as described above; a loading arm system of a loading sled in the LNG loading and unloading site connected to the first end of the static electric safety control system; and an LNG tank car connected to the second end of the static electric safety control system.

[0017] In addition, the embodiment of the present application further provides an electrostatic safety control method for an LNG loading and unloading site, which is implemented according to the electrostatic safety control system as described above, wherein the electrostatic safety control method comprises: detecting, by the electrostatic grounding self-detection device, the electrostatic grounding state of the LNG tank truck; diagnosing, by the control device, whether the tank truck grounding detection is qualified according to the electrostatic grounding state; detecting, by the human body electrostatic monitoring device, the human body electrostatic potential of the operating personnel in real time; when the grounding detection is qualified, diagnosing, by the control device, whether the electrostatic potential of the operating personnel before and after the loading and unloading operation is implemented is in a safe state according to the human body electrostatic potential, so as to output a response control strategy of indicating interrupting the loading and unloading operation for the unsafe operating state.

[0018] Preferably, the human body electrostatic monitoring device is implemented by using a non-contact electric field sensor array, which is arranged in an operating area where the loading and unloading operating personnel are located.

[0019] Compared with the prior art, one or more embodiments in the above solution can have the following advantages or beneficial effects:

[0020] The present application provides an electrostatic safety control system and method for an LNG loading and unloading site. The system and method control the quick connection between the loading and unloading arm and the tank truck and the emergency cut-off of LNG delivery through the specified on-off control of the quick connector and the quick cut-off valve, prevent continuous leakage of LNG, and prevent the formation of a large range of flammable materials; by monitoring the human body electrostatic charging of the personnel engaged in LNG loading and unloading operations and issuing an alarm in the case of high static electricity, even automatically cutting off the loading and unloading pipeline and the LNG operation box liquid / gas pipeline, to prevent human body electrostatic discharge; by the human body electrostatic grounding monitoring, the tank truck electrostatic grounding detection system and the control system configuration interlocking, combined with the water mist atomization system of the loading and unloading site, actively preventing and controlling the human body electrostatic in the loading and unloading area, preventing potential charged human bodies from inducing leakage and explosion accidents of volatile flammable gas, and ensuring the safety of the operating personnel. The present application can effectively prevent the occurrence of high human body electrostatic and poor equipment grounding in the LNG loading and unloading operation area, and form the corresponding response measures, thereby ensuring the safety of the site operation.

[0021] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application can be realized and achieved by the structure particularly pointed out in the specification, claims and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0022] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, illustrate embodiments of the present application, and are used to explain the present application together with the embodiments of the present application, and do not constitute a limitation on the present application. In the drawings:

[0023] Figure 1 Fig. 1 is a schematic diagram of an overall structure of an electrostatic safety control system for an LNG loading and unloading site according to an embodiment of the present application.

[0024] Figure 2 Fig. 2 is a schematic diagram of a specific structure of an electrostatic safety control system for an LNG loading and unloading site according to an embodiment of the present application.

[0025] Figure 3 Fig. 3 is a schematic diagram of an example of a non-contact electric field sensor array used in an electrostatic safety control system for an LNG loading and unloading site according to an embodiment of the present application.

[0026] Figure 4 Fig. 4 is a schematic diagram of an implementation flow of an electrostatic safety control system for an LNG loading and unloading site according to an embodiment of the present application.

[0027] Figure 5 Fig. 5 is a schematic diagram of an overall step of an electrostatic safety control method for an LNG loading and unloading site according to an embodiment of the present application. DETAILED DESCRIPTION

[0028] The embodiments of the present application will be described in detail with reference to the drawings and embodiments below, by which the technical means applied by the present application to solve the technical problems and achieve the technical effects can be fully understood and implemented. It should be noted that, unless there is a conflict, each embodiment in the present application and each feature in each embodiment can be combined with each other, and the technical solutions formed thereby are within the protection scope of the present application.

[0029] In addition, the steps shown in the flowchart of the drawings can be executed in a computer system such as a set of computer-executable instructions. Moreover, although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0030] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the example embodiments. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0031] LNG is a natural gas (main component methane) after compression, cooling to its freezing point (-161.5 ℃) temperature after liquid fossil fuel, it has the characteristics of low temperature, easy vaporization. At present, LNG as clean energy, its in LNG receiving station, LNG liquefaction plant complete LNG tank truck loading operation, using tank truck through the land to complete the LNG transfer operation. For pure methane, its minimum ignition energy is about 0.47 mJ, and the explosion limit of methane in air is about 5% to 15%, among which the explosion is most violent when the methane is about 9.5%. Once LNG leakage and large evaporation occur, static electricity accumulation and spark discharge may be caused by human body static discharge, poor grounding and other reasons, resulting in static explosion accidents in LNG loading station and other loading places.

[0032] At present, LNG loading station mainly eliminates tank truck static electricity and human body static electricity by installing tank truck static electricity grounding detector and human body static electricity eliminator near the loading pry. Among them, after the tank truck is parked in the loading station, the tank truck loading personnel (tank truck driver and site management personnel) touch the human body static electricity eliminator ball, open the tank truck tail operation box door and clamp the tank truck static electricity grounding detector grounding clamp on the tank truck metal body. However, in the existing patent documents CN201665524U, CN101830422A, CN101830422B and CN202769269U about LNG loading station, when the disclosed low temperature land fluid loading and unloading arm (ultra low temperature fluid loading and unloading arm) is used for tank truck loading, manual low temperature valves are arranged on the liquid phase arm and gas phase arm of the loading and unloading arm, and the end of the loading and unloading arm is connected by loose sleeve flange, which causes that the existing loading and unloading arm still needs to manually tighten 16 nuts of the liquid phase arm and gas phase arm flanges before LNG loading, so as to complete the butt joint of the tank truck and the loading and unloading arm; when the loading is completed, the corresponding gas phase arm and liquid phase arm butt joint flanges are disassembled. Generally, the LNG loading time is 30-60 min, and the operator must monitor whether the loading arm and LNG tank truck leak in the field during the LNG loading process. Therefore, if the leakage occurs in the sealing part of the universal joint, valve and flange of the loading arm, the corresponding valve on the tank truck operation box and the loading and unloading arm must be manually closed on site, so as to prevent continuous leakage of LNG in the tank truck. Otherwise, if the universal joint and flange plate of the loading arm leak (or residual liquid leaks), it will cause LNG to rapidly gasify and form an explosion space, which will cause explosion when encountering static discharge and other sparks.

[0033] In addition, electrostatic discharge from the human body is a major ignition source in LNG loading areas. Due to the long loading time of LNG operations, it is inevitable that personnel will accumulate static electricity due to prolonged on-site movement and monitoring of the loading process. While personnel handling liquefied hydrocarbons must wear anti-static shoes and clothing, the quality of these items, frequent washing, or exceeding their service life can cause them to fail to meet safety standards. Especially during the dry winter months, it is crucial to prevent excessive static electricity in LNG work areas to avoid igniting leaked or vaporized methane gas. Existing patent document CN217736923U discloses an anti-static monitoring system for LNG refueling stations. This system primarily identifies personnel entering the plant through video monitoring, detects static electricity, and prompts them to manually touch a static eliminator to eliminate it. However, this requires a high degree of self-discipline from the personnel, making its implementation inherently risky.

[0034] In summary, because traditional tank truck electrostatic grounding detectors are isolated systems and cannot be interlocked with the loading and unloading control system during LNG loading and unloading, it is difficult to completely eliminate the potential hazards of electrostatic discharge at LNG loading and unloading sites. Therefore, existing LNG loading and unloading sites lack a device that can monitor and eliminate static electricity from the human body during loading and unloading operations, in order to solve the risk of static electricity from the human body and / or electrostatic discharge from the tank truck during manual operations at LNG loading sites in the existing technology.

[0035] To address the technical problems mentioned above, this application proposes an electrostatic safety control system and method for LNG loading and unloading sites. This system and method include controls to quickly shut down the loading system when there is no leakage in the LNG loading system, when leakage occurs and human static electricity is detected, or when the vehicle grounding status is abnormal. Simultaneously, it provides audible and visual alarms and actively eliminates static electricity.

[0036] Example One

[0037] Figure 1 This is a schematic diagram of the overall structure of an electrostatic safety control system for LNG loading and unloading sites, according to an embodiment of this application. Figure 1 As shown, the electrostatic safety control system described in this embodiment of the invention includes: an electrostatic grounding self-detection device A (see...) Figure 2 Component 4), Human body static electricity monitoring device B and control device C (see...) Figure 2 Component 8 in the middle.

[0038] The static grounding self-detection device A is used for detecting the static grounding state of the LNG tank truck in real time. The human body static electricity monitoring device B is used for detecting the human body static electricity potential of the operator in real time. The control device C is used for diagnosing whether the tank truck grounding detection is qualified according to the real-time detected static grounding state, and diagnosing whether the static electricity potential of the operator before and after the loading and unloading operation is in a safe state according to the real-time detected human body static electricity potential when the grounding detection is qualified, so as to output a response control strategy of interrupting the loading and unloading operation for the unsafe operation state.

[0039] It should be noted that although the human body static electricity potential detection implemented by the control device C starts after the previous tank truck grounding detection is qualified, the tank truck grounding state still needs to be detected synchronously in the process of continuously detecting the human body static electricity potential before and after the loading and unloading operation, and if the control device C detects that the tank truck grounding state is unqualified (i.e. the tank truck static grounding is poor), an interrupt instruction for the loading and unloading operation is immediately generated. The interrupt instruction for the loading and unloading operation includes a first type of on-off control instruction for controlling the disconnection of the loading pry and the loading arm, and a second type of on-off control instruction for controlling the disconnection of the loading arm and the tank truck operation box.

[0040] Therefore, the tank truck grounding state detection task carried out by the embodiment of the present application is throughout the time period before, during and after the loading operation, and the interrupt instruction for the loading and unloading operation generated based on the abnormal grounding state has the highest response authority.

[0041] In addition, the control device C can also be connected to and communicate with the controllers in the loading arm system and the tank truck operation box system. In this way, when the controller in the loading arm system or the tank truck operation box system detects a leakage event in the loading arm area or the tank truck operation box area, the control device C can obtain the leakage event response instruction sent by the controller in the loading arm system or the tank truck operation box system, and immediately generate the above-mentioned interrupt instruction for the loading and unloading operation, thereby ensuring the safety of the loading and unloading site and personnel.

[0042] Figure 2 The specific structure diagram of the static electricity safety control system for the LNG loading and unloading site of the embodiment of the present application.

[0043] The installation position of the electrostatic safety control system of the LNG loading and unloading site cannot block the movement of the tank truck 2, and therefore the human body electrostatic monitoring device B and the electrostatic grounding self-detection device A (component 4) need to be installed near the loading pry 1 and cannot affect the movement of the loading arm 3. Before the operator connects the electrostatic grounding self-detection device A with the tank truck 2, the operator needs to actively touch the human body electrostatic monitoring device B. Since the LNG tank truck filling time is generally 30-60 min, during this period, the operator will not actively touch the human body electrostatic monitoring device B and the human body electrostatic eliminator on site of the LNG loading and unloading site.

[0044] The control device C (component 8) is electrically connected with the electrostatic grounding self-detection device A. The control device 8 detects the electrostatic grounding condition of the tank truck 2 in real time through the electrostatic grounding self-detection device 4, and the electrostatic grounding self-detection device 4 also provides an audible and visual signal indicating the grounding state of the tank truck. When the tank truck 2 is not grounded well, the control device 8 issues a first type of on-off control instruction for controlling the loading pry 1 and the loading arm (the loading gas phase arm 301 and the loading liquid phase arm 302) to be disconnected, and a second type of on-off control instruction for controlling the loading arm (the loading gas phase arm 301 and the loading liquid phase arm 302) to be disconnected with the gas phase pipeline interface and the liquid phase pipeline interface in the tank truck operation box 2, respectively, so as to quickly cut off the power gas source of the tank truck gas phase pipeline emergency shut-off valve 501, the tank truck liquid phase pipeline emergency shut-off valve 502, the quick shut-off valve 901 for the loading arm gas phase arm, and the quick shut-off valve 902 for the loading arm liquid phase arm, so as to ensure that each valve body is in a closed state.

[0045] In the embodiment of the present application, the control device 8 is installed in an explosion-proof junction box at the work site, or can be installed in a non-explosion-proof place (such as a control room).

[0046] As shown in Figure 2 , the human body electrostatic monitoring device B in the embodiment of the present application is implemented by using a non-contact electric field sensor array. The non-contact electric field sensor array is arranged in the work area where the loading and unloading operators are located. In one embodiment, the non-contact electric field sensor array is installed on a clamp or a mobile operating column through a connecting line.

[0047] As shown in Figure 3 , the non-contact electric field sensor array includes a plurality of non-contact electric field sensors 701, 702, 703, 704, … The non-contact electric field sensor array tests the electric field change of a specific space within a certain space and distance range through a specific space formed by each sensor, so as to obtain the human body electrostatic charging information of the on-site operator. For example, if the non-contact electric field sensor is installed on the body of the on-site operator, the non-contact electric field sensor array can directly test the human body electrostatic potential.

[0048] In this embodiment of the invention, the non-contact electric field sensors 701-704 are movable components. Specifically, refer to... Figure 2 The non-contact electric field sensors can be distributed at the following locations:

[0049] At the end of the loading arm inside the loading skid in the LNG loading and unloading area, and at the gas and liquid phase pipeline inlets at the rear end of the tank truck control box.

[0050] Universal joints and valves inside the loading arm;

[0051] The valves inside the tank truck's control box.

[0052] In one embodiment, the sensing probes of the non-contact electric field sensors 701-704 can be directly clamped to the dry connector 601 at the end of the gas phase arm and the dry connector 602 at the end of the liquid phase arm using a clip-on bracket, or they can be clamped to the rear end of the tank truck or the metal parts of the loading arm. In another embodiment, the sensing probes of the non-contact electric field sensors 701-704 can be installed near the universal joint or manual valve using a movable operating column, especially within a certain range of the LNG dry connector, with a reasonable layout. In yet another embodiment, the non-contact electric field sensors 701-704 can be powered by the electrostatic grounding self-detection device 4 and form a human body electrostatic monitoring device, thereby transmitting the human body electrostatic signal to the control device 8 via a signal line.

[0053] Furthermore, the first type of on / off control command described in this embodiment of the invention is used to control the on / off state of the loading arm gas phase quick (emergency) shut-off valve 901 and loading arm liquid phase quick (emergency) shut-off valve 902, which are used to connect the gas phase pipeline interface and liquid phase pipeline interface on the loading skid 1 to the gas phase arm 301 and liquid phase arm 302 in the loading arm, respectively. The second type of on / off control command is used to control the on / off state of the tank truck gas phase pipeline emergency shut-off valve 501 and tank truck liquid phase pipeline emergency shut-off valve 502, which are used to connect the gas phase arm 301 and liquid phase arm 302 in the loading arm to the gas phase pipeline interface (near 501) and liquid phase pipeline interface (near 502) in the tank truck operation box 2, respectively.

[0054] Specifically, such as Figure 2 As shown, tank truck 2 enters the loading area. Tank truck 2 is connected to loading arms 301 and 302 via LNG dry connectors 6. Tank truck 2 is connected to dry connectors 6 via manual / pneumatic integrated emergency shut-off valves 501 and 502. Loading arms 3 and loading skid 1 are connected via quick shut-off valves 901 and 902. Thus, quick shut-off valves 901 and 902 can be used to cut off the pipeline transport between loading skid and loading arm, and emergency shut-off valves 501 and 502, which are respectively fixedly installed on the gas phase pipeline interface and the liquid phase pipeline interface of tank truck 2, can be used to cut off the leakage of tank truck 2.

[0055] Further, the installation position of the dry joint 601, 602 is the operation box at the tail end of the LNG tank car. The dry joint 601, 602 comprises a male head and a female head, wherein the male head and the female head adopt a stop valve design, and can be bidirectionally conducted after being connected in a sealed manner, and meanwhile have a quick connection function; wherein the female head of the joint 601, 602 is respectively installed at the end of the gas phase arm 301 and the liquid phase arm 302, and the male head of the joint 601, 602 is respectively installed at the inlet of the corresponding gas phase pipeline and liquid phase pipeline of the tank car 2, for realizing the quick connection between the tank car 2 and the loading arm.

[0056] In addition, the electrostatic safety control system provided by the embodiment of the present application further comprises a water droplet atomization device 10. The water droplet atomization device 10 is installed at the top of the loading station canopy or the loading pry 1. The water droplet atomization device 10 can spray fine water mist, so as to atomize and humidify the loading and unloading area.

[0057] The water droplet atomization device 10 is used to actively atomize and humidify the current loading and unloading operation area under the control of a humidification instruction, so that the relative humidity of the loading and unloading operation area is kept above a preset humidity threshold. The humidification time is not less than 45 minutes, and the preset humidity threshold is 50%.

[0058] In the embodiment of the present application, the start of the water droplet atomization device 10 is realized by the control device 8. The control device 8 is also used to generate a humidification instruction and send the humidification instruction to the water droplet atomization device 10 when it is detected that the static potential of the operator in the loading and unloading operation process is in an unqualified state, so as to make the water droplet atomization device 10 start and automatically actively atomize and humidify the current loading and unloading operation area.

[0059] Example Two

[0060] Figure 4 The figure is a flowchart for implementing the electrostatic safety control system for the LNG loading and unloading site according to the embodiment of the present application. The implementation process of the electrostatic safety control system according to the embodiment of the present application will be specifically described below based on the above-mentioned embodiment one.

[0061] In one embodiment, the control device 8 is used to dynamically diagnose the qualification of the tank car grounding detection according to the real-time detected tank car-to-ground capacitance value, tank car-to-ground leakage resistance and grounding resistance of the electrostatic grounding self-detection device. The tank car-to-ground leakage resistance is the resistance between the whole tank car and the ground, and the grounding resistance is the resistance between the electrostatic grounding self-detection device connected to the tank car and the grounding net.

[0062] When the control device 8 detects that the tank car ground capacitance value does not reach the preset capacitance threshold value, or the ground leakage resistance or the grounding resistance exceeds the corresponding preset resistance threshold value, the first type of on-off control instruction for controlling the disconnection of the loading pry 1 and the loading arm 301, 302 is output, the second type of on-off control instruction for controlling the disconnection of the loading arm 301, 302 and the tank car operation box 2 is output, and the current tank car ground detection unqualified state is indicated and warned. In addition, when the control device 8 detects that the tank car ground capacitance value reaches or exceeds the preset capacitance threshold value, and neither the ground leakage resistance nor the grounding resistance exceeds the corresponding preset resistance threshold value, the indication information of the qualified electrostatic grounding detection is output.

[0063] As shown in Figure 4 , first, the electrostatic grounding self-detection device 4 detects the grounding conditions of the tank car and itself, and the control device 8 diagnoses to determine whether the tank car electrostatic grounding meets the preset resistance threshold value (for example, the self-grounding resistance is greater than 4Ω, and the tank car leakage resistance is greater than 1000Ω). If not, the control device sends an audible and light alarm signal, and sends a control instruction for controlling the quick disconnection of the shut-off valve 901, 902, so that the tank car loading operation is not allowed to be performed.

[0064] Secondly, the electrostatic grounding self-detection device 4 also detects the tank car capacitance, and the control device 8 diagnoses to determine whether the tank car ground capacitance is less than the preset capacitance threshold value (for example, 500pF). If it is less, it is considered that the tank car electrostatic grounding is not perfect or the electrostatic grounding self-detection device 4 and the tank car cannot be perfectly connected. At this time, an audible and light alarm signal is sent, and a control instruction for controlling the quick disconnection of the shut-off valve 901, 902 is sent, so that the tank car loading operation is not allowed to be performed.

[0065] If the control device 8 determines that the current tank car electrostatic grounding condition is good, the conditions of grounding resistance ≤ 4Ω, ground leakage resistance ≤ 1000Ω, and tank car capacitance ≥ 500pF must be met at the same time. At this time, the indication information of the qualified electrostatic grounding detection is output.

[0066] Continuing to refer to Figure 4 , the control device 8 of the embodiment of the present application is also used to diagnose whether to start the loading and unloading operation according to the real-time detected human body electrostatic potential by using the preset electrostatic potential threshold value after obtaining the indication information of the qualified electrostatic grounding detection. When the control device 8 detects that the human body electrostatic potential reaches or exceeds the preset electrostatic potential threshold value, the first type of on-off control instruction for controlling the disconnection of the loading pry 1 and the loading arm is output, and the current human body electrostatic detection unqualified state is indicated and warned (for example, audible and light alarm).

[0067] In addition, when the control device 8 detects that the human body static electric potential does not reach the preset static electric potential threshold, an instruction information allowing the loading and unloading operation is output. At this time, since the human body static electric potential of the operator in the operation area meets the preset threshold, the control device 8 can issue a control instruction for quickly controlling the connection of the loading arm and the tank car, so as to control the opening of the cut-off valves 501 and 502, and then allow the operator to perform the LNG loading and unloading operation.

[0068] Further, the control device 8 is also used to, after obtaining the instruction information allowing the loading and unloading operation, continue to diagnose the qualified state of the static electric potential of the operator during the loading and unloading operation according to the real-time detected human body static electric potential by using the preset static electric potential threshold. When the control device 8 detects that the current human body static electric potential reaches or exceeds the preset static electric potential threshold, a first type of on-off control instruction for controlling the disconnection of the loading pry and the loading arm is output, and an indication warning (for example, an audible and visual alarm) is performed for the unqualified state of the current human body static electric potential. At this time, since the current loading and unloading operation has been started, the current indication warning information is used to indicate that the on-site operator quickly evacuates, and a humidification instruction is generated to start the water droplet atomization device 10 to automatically perform atomization humidification processing on the current loading and unloading operation area, so as to eliminate the current static electricity; at the same time, the instruction information not allowing the disassembly of the quick connector 601 and 602 is output.

[0069] In addition, when the control device 8 detects that the human body static electric potential does not reach the preset static electric potential threshold, an instruction information allowing the loading and unloading operation is output. At this time, since the human body static electric potential of the operator in the operation area meets the preset threshold, the control device 8 can issue a control instruction for quickly controlling the connection of the loading arm and the tank car, so as to control the opening of the cut-off valves 501 and 502, and then allow the operator to perform the LNG loading and unloading operation.

[0070] In addition, whether in the human body static electric potential detection process before starting the loading and unloading operation or in the human body static electric potential detection process after starting the loading and unloading operation, the control device 8 of the embodiment of the application is also used to compare the real-time detected human body static electric potential with a preset electric potential safety threshold, and diagnose the qualified state of the static electric potential of the operator before and after the loading and unloading operation. The electric potential safety threshold (for example, 5kV) is less than the above-mentioned static electric potential threshold (for example, 8kV).

[0071] When the control device 8 detects that the real-time human body static electric potential reaches or exceeds the preset electric potential safety threshold and does not exceed the preset static electric potential threshold, an abnormal alarm information is directly output to prompt the operator to move away from the current operation area and voice prompt the high human body static electric potential to prohibit the disassembly of the LNG dry connector.

[0072] Specifically, the control device 8 monitors the static potential data transmitted by the human body static monitoring device in real time and monitors the dynamic potential fluctuation value of the data, and when it is judged that the static potential value is in an abnormal condition (for example, once the human body static voltage of the person close to the potential leakage LNG area exceeds 5kV), the control device 8 will automatically control to issue a voice and sound-light alarm to prompt the operation personnel with large human body static to quickly move away from the operation area. If the static voltage continues to rise, the control device 8 continues to issue instructions for regulating the indication information and early warning prompt signal of the sound-light alarm, and at the same time issues instructions for controlling the closing of the quick cut-off valve 901, 902, thereby preventing the human body static discharge from igniting volatile methane and the like, and ensuring the safety of personnel and equipment on site.

[0073] Example Three

[0074] Based on the static safety control system provided in the above embodiment one and / or embodiment two, the embodiment of the present application further provides a loading and unloading mechanism for an LNG loading and unloading site. The loading and unloading mechanism comprises the static safety control system as described in the above embodiment one and / or embodiment two, a loading arm system, and an LNG tank car.

[0075] One end of the loading arm system is connected with a loading pry in the LNG loading and unloading site, and the other end of the loading arm system is connected with the first end of the static safety control system; the second end of the static safety control system is connected with the LNG tank car.

[0076] In this way, by connecting the loading arm system and the static safety control system as described in the embodiment of the present application, and connecting the static safety control system and the operation box control system of the tank car, the static safety monitoring and elimination control in the complete tank car loading and unloading operation can be realized.

[0077] Example Four

[0078] Based on the static safety control system provided in the above embodiment one and / or embodiment two, the embodiment of the present application further provides a static safety control method for an LNG loading and unloading site. The static safety control method is realized according to the static safety control system as described above.

[0079] Figure 5 The static safety control method described in the embodiment of the present application is shown in the overall step schematic diagram of the static safety control method for an LNG loading and unloading site. As shown in Figure 5 The static safety control method described in the embodiment of the present application comprises the following steps:

[0080] Step S501, detecting the static grounding state of the LNG tank car by the static grounding self-detection device 4;

[0081] Step S502, the control device 8 diagnoses whether the tank car grounding detection is qualified according to the real-time detected electrostatic grounding state;

[0082] Step S503, the human body electrostatic monitoring device is used to detect the human body electrostatic potential of the operator in real time;

[0083] Step S504, when the grounding detection is qualified, the control device 8 continues to diagnose whether the electrostatic potential of the operator before and after the loading and unloading operation is in a safe state according to the human body electrostatic potential, so as to output a response control strategy indicating interrupting the loading and unloading operation for the unsafe operation state.

[0084] In one embodiment, the human body electrostatic monitoring device is implemented by using a non-contact electric field sensor array. The non-contact electric field sensor array is arranged in the operation area where the loading and unloading operator is located.

[0085] The application discloses an electrostatic safety control system and method for an LNG loading and unloading site. The system and method control the quick connection between the loading and unloading arm and the tank car and the emergency cut-off of LNG delivery through the specified on-off control of the quick connector and the quick cut-off valve, prevent the continuous leakage of LNG, and prevent the formation of a large range of combustibles; the system and method monitor the human body electrostatic charging of the personnel in the LNG loading and unloading operation and issue an alarm in the case of large electrostatic, and even automatically cut off the loading and unloading pipeline and the LNG operation box liquid / gas pipeline, to prevent the human body electrostatic discharge; the system and method are configured to interlock the human body electrostatic grounding monitoring, the tank car electrostatic grounding detection system and the control system, combine the water misting system of the loading and unloading site, actively prevent and control the human body electrostatic in the loading and unloading area, prevent the leakage and volatile combustible gas combustion and explosion accidents induced by the potential charged human body, and ensure the personal safety of the loading and unloading operation personnel. The application can effectively prevent the occurrence of the high human body electrostatic and the poor equipment grounding in the LNG loading and unloading operation area, and form the corresponding response measures, so as to ensure the safety of the on-site operation.

[0086] The above merely describes the preferred embodiments of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

[0087] In the description of the application, unless otherwise specified and limited, the meaning of "a plurality of" is two or more; the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the purpose of facilitating the description of the application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application. In addition, the terms "first", "second", "third" and the like are only for the purpose of description and cannot be understood as indicating or implying relative importance.

[0088] In the description of the application, it should be noted that, unless otherwise specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0089] It should be understood that the embodiments disclosed in the present application are not limited to the specific structure, processing steps or materials disclosed herein, but should extend to equivalent alternatives of these features understood by those skilled in the relevant art. It should also be understood that the terms used herein are only for the purpose of describing the specific embodiments and do not mean limitation.

[0090] The phrase "one embodiment" or "an embodiment" appearing in the specification means that the specific feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the application. Therefore, the phrase "one embodiment" or "an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment.

[0091] Although the embodiments disclosed in the present application are as described above, the content described is only the embodiments adopted for the purpose of facilitating the understanding of the present application, and is not intended to limit the present application. Any person skilled in the art of the present application can make any modification and change in the form and details without departing from the spirit and scope of the present application, but the patent protection scope of the present application shall be subject to the scope defined by the appended claims.

Claims

1. An electrostatic safety control system for an LNG loading and unloading site, characterized in that, The application relates to a static grounding self-detection device for detecting the static grounding state of an LNG tank truck, a human body static electricity monitoring device for real-time detection of the human body static electricity potential of an operator, and a control device for diagnosing whether the static grounding detection of the tank truck is qualified according to the static grounding state, and for diagnosing whether the static electricity potential of the operator before and after the implementation of loading and unloading operation is in a safe state according to the human body static electricity potential when the grounding detection is qualified, so as to output a response control strategy for indicating interruption of the loading and unloading operation in an unsafe operation state, wherein the control device is further used for diagnosing whether the loading and unloading operation is started according to the real-time detected human body static electricity potential by using a preset static electricity potential threshold after obtaining the static grounding detection qualified indication information, and the diagnosis comprises: outputting a first on-off control instruction for controlling the disconnection of a loading pry and a loading arm and giving an indication warning when the human body static electricity potential reaches or exceeds the preset static electricity potential threshold; and outputting indication information for allowing the loading and unloading operation when the human body static electricity potential does not reach the preset static electricity potential threshold. The control device is further used for diagnosing the qualified state of the static electricity potential of the operator during the loading and unloading operation according to the real-time detected human body static electricity potential by using the preset static electricity potential threshold after obtaining the indication information for allowing the loading and unloading operation, and the diagnosis comprises: outputting the first on-off control instruction and giving an indication warning when the human body static electricity potential reaches or exceeds the preset static electricity potential threshold; and outputting the first on-off control instruction for controlling the disconnection of the loading pry and the loading arm after the completion of the LNG loading and unloading when the human body static electricity potential does not reach the preset static electricity potential threshold. The control device is further used for comparing the real-time detected human body static electricity potential with a preset potential safety threshold to diagnose the qualified state of the static electricity potential of the operator during the loading and unloading operation, and the potential safety threshold is smaller than the static electricity potential threshold, and when the human body static electricity potential reaches or exceeds the preset potential safety threshold and does not exceed the preset static electricity potential threshold, abnormal alarm information is outputted to prompt the operator to move away from the current operation area, and humidification instructions are generated to actively perform atomization humidification treatment on the current loading and unloading operation area, so as to eliminate the current static electricity. When the human body static electricity potential does not reach the preset static electricity potential threshold until the completion of the LNG loading and unloading operation, the first on-off control instruction for controlling the disconnection of the loading pry and the loading arm is directly outputted after the completion of the LNG tank truck filling. The non-contact electric field sensors in the human body static electricity monitoring device are distributed at the following position points: the end of the loading arm in the loading pry in the LNG loading and unloading site and the gas phase and liquid phase pipeline entrances at the rear end of the tank truck operation box; the universal joint and valves in the loading arm; the valves in the tank truck operation box; and the body of the on-site operator. ​ ​ ​ ​ ​ ​ ​ ​ 2. The electrostatic safety control system of claim 1, wherein, The human body static electricity monitoring device is realized by using a non-contact electric field sensor array, the non-contact electric field sensor array is installed on a clamp or a mobile operating column through a connecting line, and the non-contact electric field sensor array is arranged in a working area where a loading and unloading worker is located. 3.The electrostatic safety control system according to claim 1 or 2, characterized in that, The control device is further used for dynamically diagnosing the eligibility of the tank truck grounding detection according to the real-time detected tank truck-to-ground capacitance value, ground leakage resistance and grounding resistance, wherein, When it is detected that the tank truck-to-ground capacitance value does not reach a preset capacitance threshold, or the ground leakage resistance or the grounding resistance exceeds a corresponding preset resistance threshold, a first type of on-off control instruction for controlling the loading pry to be disconnected from the loading arm and a second type of on-off control instruction for controlling the loading arm to be disconnected from the tank truck operation box are output, and a pre-warning indication is performed; When it is detected that the tank truck-to-ground capacitance value reaches or exceeds the preset capacitance threshold, and the ground leakage resistance and the grounding resistance do not exceed the corresponding preset resistance threshold, an indication information that the electrostatic grounding detection is qualified is output. 4.The electrostatic safety control system according to claim 3, characterized in that, The first type of on-off control instruction is used for controlling the on-off state of a loading arm gas phase quick shut-off valve and a loading arm liquid phase quick shut-off valve used for connecting the gas phase pipeline interface and the liquid phase pipeline interface on the loading pry to the gas phase arm and the liquid phase arm in the loading arm respectively; The second type of on-off control instruction is used for controlling the on-off state of a tank truck gas phase pipeline emergency shut-off valve and a tank truck liquid phase pipeline emergency shut-off valve used for connecting the gas phase arm and the liquid phase arm in the loading arm to the gas phase pipeline interface and the liquid phase pipeline interface in the tank truck operation box respectively.

5. The electrostatic safety control system of claim 3, wherein, The electrostatic safety control system further comprises: A water droplet atomization device installed at the top of a loading station canopy or a loading pry, used for actively atomizing and humidifying the current loading and unloading working area under the control of a humidifying instruction, so that the relative humidity of the loading and unloading working area is maintained above a preset humidity threshold, wherein the humidifying time is not less than 45 min and the preset humidity threshold is 50%, wherein, The control device is further used for generating the humidifying instruction and sending the humidifying instruction to the water droplet atomization device when it is detected that the electrostatic potential of the worker in the loading and unloading process is in an unqualified state.

6. A loading and unloading mechanism for an LNG loading and unloading site, characterized by, It comprises: The electrostatic safety control system according to any one of claims 1-5; The loading arm system of the loading pry in the LNG loading and unloading field is connected with the first end of the electrostatic safety control system; and The LNG tank truck is connected with the second end of the electrostatic safety control system.

7. A method of electrostatic safety control for an LNG loading / unloading site, characterized by, The electrostatic safety control method is realized according to the electrostatic safety control system according to any one of claims 1-5, wherein the electrostatic safety control method comprises: Detecting the electrostatic grounding state of the LNG tank truck by the electrostatic grounding self-detection device; The control device diagnoses whether the tank truck grounding detection is qualified according to the electrostatic grounding state; The human body static electricity potential of the worker is detected in real time by a human body static electricity monitoring device; When the grounding detection is qualified, the control device diagnoses whether the static electricity potential of the worker before and after the loading and unloading operation is in a safe state according to the human body static electricity potential, so as to output a response control strategy indicating interrupting the loading and unloading operation for the unsafe operation state.

8. The electrostatic safety control method according to claim 7, wherein The human body static electricity monitoring device is implemented by using a non-contact electric field sensor array which is arranged in a working area where the loading and unloading worker is located.

Images