Electrostatic safety control system and method for LNG loading and unloading place

Abstract

The invention discloses an electrostatic safety control system and method for an LNG loading and unloading place, and the system comprises an electrostatic grounding self-detection device which is used for detecting the electrostatic grounding state of an LNG tank car; the human body static monitoring device is used for detecting the human body static potential of an operator in real time; and the control device is used for diagnosing whether the grounding detection of the tank car is qualified according to the electrostatic grounding state, and diagnosing whether the electrostatic potential of the operator is in a safe state before and after the loading and unloading operation is implemented according to the electrostatic potential of the human body when the grounding detection is qualified, so as to output a coping control strategy indicating the interruption of the loading and unloading operation in an unsafe operation state. According to the device, the situations that human body static electricity is too high and equipment grounding is poor in an LNG loading and unloading operation area can be effectively prevented, and corresponding countermeasures are formed, so that field operation safety is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas storage and transportation safety, and in particular to an electrostatic safety control system and method for LNG loading and unloading sites. Background Art

[0002] LNG is a liquid fossil fuel after natural gas (main component methane) is compressed and cooled to its freezing point (-161.5℃). It has the characteristics of low temperature and easy vaporization. At present, LNG, as a clean energy, is used to load LNG tank trucks at LNG receiving stations and LNG liquefaction plants, and to transport LNG by land using tank trucks. For pure methane, its minimum ignition energy is about 0.47mJ, and the explosion limit of methane in the air is about 5% to 15%, among which methane explodes most violently at about 9.5%. Once LNG leaks and evaporates in large quantities, it may cause static electricity accumulation in the tank truck and induce spark discharge due to reasons such as human static electricity discharge and poor grounding, causing static electricity explosion accidents at loading sites such as LNG receiving stations.

[0003] At present, LNG loading stations mainly use tank truck static grounding detectors and human static eliminators installed near the loading skid to eliminate static electricity in tank trucks and on human bodies. After the tank truck stops at the loading station, the tank truck loading personnel (tank truck drivers and on-site managers) touch the ball of the human static eliminator, open the operating box door at the rear of the tank truck, and clamp the grounding clamp of the tank truck static grounding detector to the metal body of the tank truck. However, in the existing patent documents CN201665524U, CN101830422A, CN101830422B, and CN202769269U on LNG loading stations, when the disclosed low-temperature land-based fluid loading and unloading arm (ultra-low-temperature fluid loading and unloading arm) is loaded into a tank truck, manual low-temperature valves are set on the liquid phase arm and the gas phase arm of the loading and unloading arm, and the end of the loading and unloading arm is connected with a loose flange, resulting in the existing loading and unloading arm still needing to manually tighten the liquid phase arm and the gas phase arm flanges, a total of 16 nuts, before LNG loading, to complete the docking between the tank truck and the loading and unloading arm; when 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. During the LNG loading process, the operator must monitor the loading arm and the LNG tank truck at all times on site to see if there is any leakage. Therefore, if leakage occurs at the universal joint, valve, flange and other sealing parts of the loading arm, the corresponding valves on the tank truck operation box and the loading and unloading arm must be closed manually on site to prevent the continuous leakage of LNG in the tank truck. Otherwise, once the universal joint and flange of the loading arm leak (or residual liquid leaks), LNG will quickly gasify to form an explosion space, which will cause an explosion when encountering sparks such as static discharge.

[0004] In addition, human body static discharge is the main ignition source in the LNG loading area. Since the LNG loading operation takes a long time, it is inevitable that the operator will be charged while walking on site for a long time and monitoring the loading process for abnormalities. Operators need to wear anti-static shoes and clothes, but due to the quality of anti-static shoes / anti-static work clothes, long-term cleaning or exceeding the use period, the anti-static shoes and clothes will not meet the safety standards. Especially in the dry winter season, LNG workplaces must prevent the occurrence of excessive human static electricity to prevent human body static electricity discharge and other ignition of leaked and gasified methane gas. The existing patent document CN217736923U discloses an anti-static monitoring system for LNG filling stations, which mainly uses video surveillance to identify staff entering the factory and detect human body static electricity and prompt the human body to manually touch the human body static eliminator to eliminate human body static electricity, but this requires a high degree of self-consciousness and initiative from the operators, so that this solution still has a large risk during implementation.

[0005] To sum up, since the traditional tank truck electrostatic grounding detector is an information island, it cannot be interlocked with the loading and unloading control system during the LNG loading and unloading process, and it is difficult to completely eliminate the hidden dangers of electrostatic hazards in LNG loading and unloading sites. Therefore, the existing LNG loading and unloading sites lack a device that can be used to monitor and eliminate human body static electricity during loading and unloading operations, so as to solve the risk of human body static electricity and / or tank truck static electricity discharge during manual operations in LNG loading sites in the prior art. Summary of the invention

[0006] The purpose of the present invention is to propose an electrostatic safety control solution for LNG loading and unloading sites to solve the risk of static electricity on the human body and / or static electricity discharge on tank trucks during manual operations at LNG loading sites in the prior art.

[0007] In order to solve the above technical problems, an embodiment of the present invention provides an electrostatic safety control system for LNG loading and unloading sites, including: an electrostatic grounding self-detection device, which is used to detect the electrostatic grounding status of the LNG tank truck; a human body electrostatic monitoring device, which is used to detect the human body electrostatic potential of the operator in real time; a control device, which is used to diagnose whether the tank truck grounding detection is qualified according to the electrostatic grounding status, and when the grounding detection is qualified, 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, thereby outputting a response control strategy for interrupting the loading and unloading operation for an unsafe operating state.

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

[0009] Preferably, the non-contact electric field sensors are distributed at the following locations: the end of the loading arm in the loading skid in the LNG loading and unloading site, and the gas and liquid pipeline inlets at the rear end of the tank truck operating box; the universal joint and valves in the loading arm; and the valves in the tank truck operating box.

[0010] Preferably, the control device is also used to dynamically diagnose the qualification of the tank truck grounding detection based on the real-time detected tank truck capacitance to ground, ground leakage resistance and grounding resistance, wherein, when it is detected that the tank truck capacitance to ground does not reach the preset capacitance threshold, or the ground leakage resistance or the grounding resistance exceeds the corresponding preset resistance threshold, a first type of on-off control instruction for controlling the disconnection between the loading skid and the loading arm, and a second type of on-off control instruction for controlling the disconnection between the loading arm and the tank truck operating box are output, and an indication warning is given; when it is detected that the tank truck capacitance to ground reaches or exceeds the preset capacitance threshold, and both 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.

[0011] Preferably, the control device is further used to diagnose whether to start loading and unloading operations based on the real-time detected human body electrostatic potential and a preset electrostatic potential threshold after obtaining the electrostatic grounding detection qualified indication information, wherein when it is detected that the human body electrostatic potential reaches or exceeds the preset electrostatic potential threshold, a first type of on-off control instruction for controlling the disconnection between the loading skid and the loading arm is output, and an indication warning is issued; when it is detected that the human body electrostatic potential does not reach the preset electrostatic potential threshold, an indication information allowing loading and unloading operations is output.

[0012] Preferably, the control device is further used to diagnose the qualified state of the electrostatic potential of the operator during the loading and unloading operation according to the real-time detected electrostatic potential of the human body and using a preset electrostatic potential threshold after obtaining the indication information allowing the loading and unloading operation, wherein, when it is detected that the electrostatic potential of the human body reaches or exceeds the preset electrostatic potential threshold, a first type of on-off control instruction for controlling the disconnection between the loading skid and the loading arm is output and an indication warning is given; when it is detected that the electrostatic potential of the human body does not reach the preset electrostatic potential threshold, the first type of on-off control instruction for controlling the disconnection between the loading skid and the loading arm is output after the LNG loading and unloading is completed.

[0013] Preferably, the control device is also used to compare the real-time detected human body electrostatic potential with a preset potential safety threshold, and diagnose the qualified state of the operator's electrostatic potential before and after the loading and unloading operation, and the potential safety threshold is less than the electrostatic potential threshold. When it is detected that the human body's electrostatic potential reaches or exceeds the preset potential safety threshold and does not exceed the preset electrostatic potential threshold, an abnormal alarm message is output to prompt the staff to stay away from the current working area.

[0014] Preferably, the first type of on-off control instructions are used to control the on-off states of the loading arm gas phase quick shut-off valve and the loading arm liquid phase quick shut-off valve, which are used to connect the gas phase pipeline interface and the liquid phase pipeline interface on the loading skid with the gas phase arm and the liquid phase arm in the loading arm respectively; the second type of on-off control instructions are used to control the on-off states of the tank truck gas phase pipeline emergency shut-off valve and the tank truck liquid phase pipeline emergency shut-off valve, which are used to connect the gas phase arm and the liquid phase arm in the loading arm with the gas phase pipeline interface and the liquid phase pipeline interface in the tank truck operating box respectively.

[0015] Preferably, the electrostatic safety control system also includes: a water droplet atomization device, which is installed on the top of the loading station canopy or at the loading skid, and is used to actively perform atomization humidification in 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 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 also used to generate the humidification instruction and send the humidification instruction to the water droplet atomization device when it is detected that the electrostatic potential of the operator during the loading and unloading operation is in an unqualified state.

[0016] On the other hand, an embodiment of the present invention provides a loading and unloading mechanism for an LNG loading and unloading site, comprising: the electrostatic safety control system as described above; a loading arm system of a loading skid in the LNG loading and unloading site, which is connected to the first end of the electrostatic safety control system; and an LNG tank truck, which is connected to the second end of the electrostatic safety control system.

[0017] In addition, an embodiment of the present invention also provides an electrostatic safety control method for LNG loading and unloading sites, which is implemented according to the electrostatic safety control system as described above, wherein the electrostatic safety control method includes: using an electrostatic grounding self-detection device to detect the electrostatic grounding state of the LNG tank truck; the control device diagnoses whether the tank truck grounding detection is qualified according to the electrostatic grounding state; using a human body electrostatic monitoring device to detect the human body electrostatic potential of the operator in real time; when the grounding detection is qualified, the control device diagnoses 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, thereby outputting a response control strategy for interrupting the loading and unloading operation for an unsafe operating state.

[0018] Preferably, the human body static electricity monitoring device is implemented by a non-contact electric field sensor array, and the non-contact electric field sensor array is arranged in the working area where the loading and unloading workers are located.

[0019] Compared with the prior art, one or more embodiments of the above scheme may have the following advantages or beneficial effects:

[0020] The present invention proposes an electrostatic safety control system and method for LNG loading and unloading sites. The system and method control the quick connection between the loading and unloading arm and the tank truck and the emergency cut-off LNG delivery by specifying the on-off control of the quick connector and the quick cut-off valve, thereby preventing the continuous leakage of LNG and preventing the formation of large-scale combustibles; by monitoring the electrostatic charge of the human body of the personnel in the LNG loading and unloading operation and issuing an alarm when the static charge is large, and even automatically cutting off the loading and unloading pipeline and the liquid / gas phase pipeline of the LNG operation box, to prevent the occurrence of human body electrostatic discharge; by monitoring the human body electrostatic grounding, the tank truck electrostatic grounding detection system and the control system configuration interlock, combined with the loading and unloading site fine water atomization system, the human body static charge in the loading and unloading area is actively controlled, and the potential charged human body induced leakage of volatile flammable gas explosion accidents are prevented, so as to ensure the personal safety of the loading and unloading operators. The present invention can effectively prevent the occurrence of excessive human body static charge and poor equipment grounding in the LNG loading and unloading operation area, and form corresponding countermeasures, thereby ensuring the safety of on-site operations.

[0021] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0023] 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 the present application.

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

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

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

[0027] Figure 5 Schematic diagram of the overall steps of the electrostatic safety control method for LNG loading and unloading sites according to an embodiment of the present application. DETAILED DESCRIPTION

[0028] The following will describe the implementation methods of the present invention in detail with reference to the accompanying drawings and embodiments, so that the implementation process of how the present invention applies 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 of the present invention and the various features in the embodiments can be combined with each other, and the technical solutions formed are all within the protection scope of the present invention.

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

[0030] The terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms "one", "one" and "item" used herein are also intended to include plural numbers. It should also be understood that the terms "include" and / or "comprise" used herein specify the existence of stated features, integers, steps, operations, units and / or components, without excluding the existence or addition of one or more other features, integers, steps, operations, units, components and / or combinations thereof.

[0031] LNG is a liquid fossil fuel after natural gas (main component methane) is compressed and cooled to its freezing point (-161.5℃). It has the characteristics of low temperature and easy vaporization. At present, LNG, as a clean energy, is used to load LNG tank trucks at LNG receiving stations and LNG liquefaction plants, and to transport LNG by land using tank trucks. For pure methane, its minimum ignition energy is about 0.47mJ, and the explosion limit of methane in the air is about 5% to 15%, among which methane explodes most violently at about 9.5%. Once LNG leaks and evaporates in large quantities, it may cause static electricity accumulation in the tank truck and induce spark discharge due to reasons such as human static electricity discharge and poor grounding, causing static electricity explosion accidents at loading sites such as LNG receiving stations.

[0032] At present, LNG loading stations mainly use tank truck static grounding detectors and human static eliminators installed near the loading skid to eliminate static electricity in tank trucks and on human bodies. After the tank truck stops at the loading station, the tank truck loading personnel (tank truck drivers and on-site managers) touch the ball of the human static eliminator, open the operating box door at the rear of the tank truck, and clamp the grounding clamp of the tank truck static grounding detector to the metal body of the tank truck. However, in the existing patent documents CN201665524U, CN101830422A, CN101830422B, and CN202769269U on LNG loading stations, when the disclosed low-temperature land-based fluid loading and unloading arm (ultra-low-temperature fluid loading and unloading arm) is loaded into a tank truck, manual low-temperature valves are set on the liquid phase arm and the gas phase arm of the loading and unloading arm, and the end of the loading and unloading arm is connected with a loose flange, resulting in the existing loading and unloading arm still needing to manually tighten the liquid phase arm and the gas phase arm flanges, a total of 16 nuts, before LNG loading, to complete the docking between the tank truck and the loading and unloading arm; when 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. During the LNG loading process, the operator must monitor the loading arm and the LNG tank truck at all times on site to see if there is any leakage. Therefore, if leakage occurs at the universal joint, valve, flange and other sealing parts of the loading arm, the corresponding valves on the tank truck operation box and the loading and unloading arm must be closed manually on site to prevent the continuous leakage of LNG in the tank truck. Otherwise, once the universal joint and flange of the loading arm leak (or residual liquid leaks), LNG will quickly gasify to form an explosion space, which will cause an explosion when encountering sparks such as static discharge.

[0033] In addition, human body static discharge is the main ignition source in the LNG loading area. Since the LNG loading operation takes a long time, it is inevitable that the operator will be charged while walking on site for a long time and monitoring whether there are any abnormal processes during the loading process. Liquid hydrocarbon loading and unloading workers need to wear anti-static shoes and clothes, but due to the quality of anti-static shoes / anti-static work clothes, long-term cleaning or exceeding the use period, the anti-static shoes and clothes will not meet the safety standards. Especially in the dry winter season, LNG workplaces must prevent the occurrence of excessive human body static electricity to prevent human body static electricity discharge and other ignition of leaked and gasified methane gas. The existing patent document CN217736923U discloses an anti-static monitoring system for LNG filling stations, which mainly uses video surveillance to identify staff entering the factory and detect human body static electricity and prompt the human body to manually touch the human body static eliminator to eliminate human body static electricity, but this requires a high degree of self-consciousness and initiative from the operators, so that this solution still has a large risk during implementation.

[0034] To sum up, since the traditional tank truck electrostatic grounding detector is an information island, it cannot be interlocked with the loading and unloading control system during the LNG loading and unloading process. Therefore, it is difficult to completely eliminate the hidden dangers of electrostatic hazards in LNG loading and unloading sites. Therefore, the existing LNG loading and unloading sites lack a device that can be used to monitor and eliminate human body static electricity during loading and unloading operations, so as to solve the risk of human body static electricity and / or tank truck static electricity discharge during manual operations in LNG loading operations in the prior art.

[0035] In order to solve the technical problems in the above background technology, the embodiment of the present application proposes an electrostatic safety control system and method for LNG loading and unloading sites. The system and method are respectively set to quickly cut off the loading system when there is no leakage in the LNG loading system, leakage occurs and human body static electricity is detected, and the vehicle grounding state is abnormal, and at the same time, sound and light alarms are issued and static electricity is actively eliminated.

[0036] Embodiment 1

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

[0038] The electrostatic grounding self-detection device A is used to detect the electrostatic grounding status of the LNG tanker in real time. The human body electrostatic monitoring device B is used to detect the human body electrostatic potential of the operator in real time. The control device C is used to diagnose whether the tanker grounding test is qualified based on the electrostatic grounding status detected in real time, and if the grounding test is qualified, diagnose whether the electrostatic potential of the operator before and after the loading and unloading operation is in a safe state based on the human body electrostatic potential detected in real time, so as to output a response control strategy indicating the interruption of the loading and unloading operation for the unsafe operation state.

[0039] It should be noted that although the human body electrostatic potential detection implemented by the control device C is implemented after the previous tank truck grounding detection is qualified, the tank truck grounding state still needs to be synchronously detected during the continuous detection of human body electrostatic potential before and after the loading and unloading operation. If the control device C detects that the tank truck grounding state is unqualified (i.e., the tank truck electrostatic grounding is poor), a loading and unloading operation interruption instruction is immediately generated. The loading and unloading operation interruption instruction includes: a first type of on-off control instruction for controlling the disconnection of the loading skid 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] To this end, the tank truck grounding status detection task carried out by the embodiment of the present invention runs through the time periods before, during and after the entire loading operation, and the loading and unloading operation interruption instruction generated based on the abnormal grounding status has the highest response authority.

[0041] In addition, the control device C described in the embodiment of the present invention can also be connected to the controllers in the loading arm system and the tank truck operation box system at the same time and realize communication interaction. 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, thereby immediately generating the above-mentioned loading and unloading operation interruption instruction, thereby ensuring the safety of the loading and unloading site and personnel.

[0042] Figure 2 This is a schematic diagram of the specific structure of an electrostatic safety control system for LNG loading and unloading sites according to an embodiment of the present application.

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

[0044] The control device C (component 8) is electrically connected to the electrostatic grounding self-detection device A. The control device 8 detects the electrostatic grounding condition of the tank car 2 in real time through the electrostatic grounding self-detection device 4, and the electrostatic grounding self-detection device 4 also provides an acoustic and optical signal indicating the grounding state of the tank car. When the tank car 2 is poorly grounded, the control device 8 issues a first type of on-off control instruction for controlling the disconnection of the loading skid 1 from the loading arm (loading gas phase arm 301 and loading liquid phase arm 302), and a second type of on-off control instruction for controlling the disconnection of the loading arm (loading gas phase arm 301 and loading liquid phase arm 302) from the gas phase pipeline interface and the liquid phase pipeline interface in the tank car operation box 2, respectively, so as to quickly cut off the power gas source of the tank car gas phase pipeline emergency cut-off valve 501, the tank car liquid phase pipeline emergency cut-off valve 502, the loading arm gas phase arm quick cut-off valve 901 and the loading arm liquid phase arm quick cut-off valve 902 to ensure that each valve body is in a closed state.

[0045] In the embodiment of the present invention, the control device 8 is installed in an explosion-proof junction box at the work site, and may also be installed in a non-explosion-proof location (eg, a control room).

[0046] like Figure 2 As shown, the human body static electricity monitoring device B described in the embodiment of the present invention is implemented by a non-contact electric field sensor array. The non-contact electric field sensor array is arranged in the working area where the loading and unloading workers are located. In one embodiment, the non-contact electric field sensor array is installed on a clip or a movable operating column through a connecting wire.

[0047] like Figure 3 As shown, 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 changes in a certain space around or in a specific space within a distance range through the specific space formed by each sensor, thereby obtaining the electrostatic charging information of the human body of the on-site workers. For example, if the non-contact electric field sensor is installed on the body of the on-site workers, the non-contact electric field sensor array can directly test the electrostatic potential of the human body itself.

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

[0049] The end of the loading arm in the loading skid in the LNG loading and unloading site, and the gas and liquid pipeline inlets at the rear end of the tank truck operating box;

[0050] The universal joints and valves in the loading arm;

[0051] At the valves in the tank truck operating box.

[0052] In one embodiment, the sensing probes of the non-contact electric field sensors 701-704 can be fixed by a bracket with a clip and directly clamped on the dry joint 601 at the end of the gas phase arm of the loading vehicle and the dry joint 602 at the end of the liquid phase arm of the loading vehicle, or can be clamped on 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 and manual valve through a movable operating column, especially reasonably arranged within a certain range of the LNG dry joint. In another embodiment, the non-contact electric field sensors 701-704 can be powered by the electrostatic grounding self-detection device 4 and constitute a human body electrostatic monitoring device, thereby sending the human body electrostatic signal to the control device 8 through the signal line.

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

[0054] Specifically, Figure 2 As shown, the tank truck 2 enters the loading area, and the tank truck 2 is connected to the loading arms 301, 302 through the LNG dry joint 6, wherein the tank truck 2 is connected to the dry joint 6 through the manual / pneumatic integrated emergency shut-off valves 501, 502, and the loading and unloading arm 3 is connected to the loading skid 1 through the quick shut-off valves 901, 902, so that the pipeline transportation between the loading skid and the loading arm can be cut off by the quick shut-off valves 901, 902, and the leakage of the tank truck 2 can be cut off by the emergency shut-off valve 501 on the gas phase pipeline interface and the emergency shut-off valve 502 on the liquid phase pipeline interface respectively fixedly installed on the tank truck 2.

[0055] Furthermore, the installation position of the dry connectors 601 and 602 is the operation box at the rear end of the LNG tanker. The dry connectors 601 and 602 include a male head and a female head, wherein the male head and the female head are designed with a stop valve, and can be bidirectionally conducted only after the connection is sealed, and have a quick connection function; wherein the female heads of the connectors 601 and 602 are respectively installed at the ends of the gas phase arm 301 and the liquid phase arm 302, and the male heads of the connectors 601 and 602 are respectively installed at the entrances of the gas phase pipeline and the liquid phase pipeline corresponding to the tanker 2, for realizing a quick connection between the tanker 2 and the loading arm.

[0056] In addition, the electrostatic safety control system described in the embodiment of the present invention further includes: a water drop atomization device 10. The water drop atomization device 10 is installed on the top of the loading station canopy or the loading skid 1. The water drop atomization device 10 can spray fine water mist, thereby atomizing and humidifying the loading and unloading area.

[0057] The water drop atomization device 10 is used to actively perform atomization humidification in the current loading and unloading operation area under the control of the humidification instruction, so that the relative humidity of the loading and unloading operation area is maintained above the 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 invention, the water drop atomization device 10 is started 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 drop atomization device 10 when it is detected that the electrostatic potential of the operator during the loading and unloading operation is in an unqualified state, so that the water drop atomization device 10 is started and automatically performs atomization and humidification processing on the current loading and unloading operation area.

[0059] Embodiment 2

[0060] Figure 4 The schematic diagram of the implementation process of the electrostatic safety control system for LNG loading and unloading sites in the embodiment of the present application is as follows. Based on the above embodiment 1, the implementation process of the electrostatic safety control system described in the embodiment of the present invention is specifically described.

[0061] In one embodiment, the control device 8 is used to dynamically diagnose the eligibility of the tank truck grounding detection based on the real-time detected tank truck-to-ground capacitance value, tank truck-to-ground leakage resistance and grounding resistance of the electrostatic grounding self-detection device. The tank truck-to-ground leakage resistance is the resistance between the tank truck as a whole and the ground, and the grounding resistance is the resistance between the electrostatic grounding self-detection device connected to the tank truck and the grounding grid.

[0062] Among them, when the control device 8 detects that the capacitance value of the tank car to the ground does not reach the preset capacitance threshold, or the leakage resistance to the ground or the grounding resistance exceeds the corresponding preset resistance threshold, the first type of on-off control instruction for controlling the disconnection of the loading skid 1 and the loading arms 301 and 302, and the second type of on-off control instruction for controlling the disconnection of the loading arms 301 and 302 from the tank car operation box 2 are output, and the current tank car grounding detection unqualified state is indicated and warned. In addition, when the control device 8 detects that the capacitance value of the tank car to the ground reaches or exceeds the preset capacitance threshold, and the leakage resistance to the ground and the grounding resistance do not exceed the corresponding preset resistance threshold, the indication information of the qualified electrostatic grounding detection is output.

[0063] like Figure 4 As shown, first, the electrostatic grounding self-detection device 4 detects the tank truck and its own grounding conditions, and the control device 8 performs diagnosis to determine whether the tank truck's electrostatic grounding meets the pre-set preset resistance threshold (for example: its own grounding resistance is greater than 4Ω, and the tank truck's leakage resistance is greater than 1000Ω) conditions. If not, the control device sends out an audible and visual alarm signal, and sends out a control instruction for controlling the quick disconnect shut-off valves 901 and 902, thereby not allowing the tank truck loading operation.

[0064] Secondly, the electrostatic grounding self-detection device 4 also detects the capacitance of the tank truck, and the control device 8 diagnoses to determine whether the capacitance of the tank truck to the ground is less than a preset capacitance threshold (for example: 500pF). If it is less than, it is considered that the electrostatic grounding of the tank truck is not intact or the electrostatic grounding self-detection device 4 is not properly connected to the tank truck. At this time, an audible and visual alarm signal is issued, and a control instruction for controlling the quick disconnect valves 901 and 902 is issued, thereby not allowing the tank truck loading operation.

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

[0066] Continue to refer Figure 4 The control device 8 described in the embodiment of the present invention is also used to diagnose whether to start the loading and unloading operation based on the real-time detected human body electrostatic potential and the preset electrostatic potential threshold after obtaining the electrostatic grounding detection qualified indication information. Among them, when the control device 8 detects that the human body electrostatic potential reaches or exceeds the preset electrostatic potential threshold, it outputs a first type of on-off control instruction for controlling the disconnection between the loading skid 1 and the loading arm, and indicates and warns the current human body electrostatic detection unqualified state (for example: sound and light alarm).

[0067] In addition, when the control device 8 detects that the electrostatic potential of the human body does not reach the preset electrostatic potential threshold, it outputs instruction information allowing loading and unloading operations. At this time, since the electrostatic potential of the human body 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 between the loading arm and the tank truck, thereby controlling the shut-off valves 501 and 502 to open, and then allowing the operator to carry out LNG loading and unloading operations.

[0068] Furthermore, the control device 8 is also used to diagnose the qualified state of the electrostatic potential of the operator during the loading and unloading operation based on the real-time detected human body electrostatic potential and the preset electrostatic potential threshold after obtaining the indication information of allowing the loading and unloading operation. Among them, when the control device 8 detects that the current human body electrostatic potential reaches or exceeds the preset electrostatic potential threshold, it outputs a first type of on-off control instruction for controlling the disconnection between the loading skid and the loading arm, and indicates and warns the current unqualified state of human body electrostatic detection (for example: sound and light alarm). At this time, since the loading and unloading operation has already started, the current indication and warning information is used to instruct the on-site operators to evacuate quickly, and a humidification instruction is generated to start the water drop atomization device 10 and automatically and actively perform atomization and humidification treatment on the current loading and unloading operation area, thereby eliminating the current static electricity; at the same time, the indication information that does not allow the quick connectors 601 and 602 to be disassembled is output.

[0069] In addition, when the control device 8 detects that the electrostatic potential of the human body has not reached the preset electrostatic potential threshold until the LNG loading and unloading operation is completed, after the LNG loading and unloading is completed, it directly outputs a first type of on-off control instruction for controlling the disconnection between the loading skid 1 and the loading arm; at the same time, it outputs instruction information allowing the quick connectors 601 and 602 to be disassembled.

[0070] In addition, whether it is the process of detecting the electrostatic potential of the human body before or after the loading and unloading operation is started, the control device 8 described in the embodiment of the present invention is also used to compare the real-time detected electrostatic potential of the human body with the preset potential safety threshold, and diagnose the qualified state of the electrostatic potential of the operator before and after the loading and unloading operation. Among them, the potential safety threshold (for example: 5kV) is less than the above-mentioned electrostatic potential threshold (for example: 8kV).

[0071] Among them, when the control device 8 detects that the real-time human body electrostatic potential reaches or exceeds the preset potential safety threshold and does not exceed the preset electrostatic potential threshold, it directly outputs abnormal alarm information to prompt the staff to stay away from the current working area and gives a voice prompt that the human body electrostatic potential is high and it is prohibited to disassemble the LNG dry joint.

[0072] Specifically, the control device 8 monitors the electrostatic potential data transmitted by the human body electrostatic monitoring device in real time and monitors the dynamic potential fluctuation value of this data. When it is determined that the electrostatic potential value is in an abnormal situation (such as: once the human body electrostatic voltage near the potential LNG leakage area exceeds 5kV), the control device 8 will automatically control the voice and sound and light alarms to prompt the operators with large human body static electricity to quickly leave the work area. If the electrostatic voltage continues to rise, the control device 8 continues to issue instructions for regulating the sound and light alarm to issue indication information and early warning prompt signals, and at the same time issues instructions for controlling the closing of the quick cut-off valves 901 and 902, thereby preventing the human body static discharge from igniting volatile methane, etc., to ensure the safety of on-site personnel and equipment.

[0073] Embodiment 3

[0074] Based on the electrostatic safety control system provided in the above embodiment 1 and / or embodiment 2, the present invention also provides a loading and unloading mechanism for LNG loading and unloading sites. The loading and unloading mechanism includes: the electrostatic safety control system as described in the above embodiment 1 and / or embodiment 2, a loading arm system, and an LNG tank truck.

[0075] One end of the loading arm system is connected to the loading skid in the LNG loading and unloading yard, and the other end of the loading arm system is connected to the first end of the electrostatic safety control system; the second end of the electrostatic safety control system is connected to the LNG tank truck.

[0076] In this way, by docking the loading arm system described in the embodiment of the present invention with the electrostatic safety control system, and docking the electrostatic safety control system with the tank truck's operating box control system, electrostatic safety monitoring and elimination control in the complete tank truck loading and unloading operation can be achieved.

[0077] Embodiment 4

[0078] Based on the electrostatic safety control system provided in the above embodiment 1 and / or embodiment 2, the present invention also provides an electrostatic safety control method for LNG loading and unloading sites. The electrostatic safety control method is implemented according to the electrostatic safety control system described above.

[0079] Figure 5 Schematic diagram of the overall steps of the static electricity safety control method for LNG loading and unloading sites according to the embodiment of the present application. Figure 5 As shown, the static electricity safety control method described in the embodiment of the present invention includes the following steps:

[0080] Step S501, the electrostatic grounding self-detection device 4 detects the electrostatic grounding state of the LNG tank truck;

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

[0082] Step S503: using a human body static electricity monitoring device to detect the human body static electricity 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 based on the electrostatic potential of the human body, thereby outputting a response control strategy indicating interruption of the loading and unloading operation for an unsafe operation state.

[0084] In one embodiment, the human body static electricity monitoring device is implemented by a non-contact electric field sensor array. The non-contact electric field sensor array is arranged in the working area where the loading and unloading workers are located.

[0085] The present invention discloses an electrostatic safety control system and method for LNG loading and unloading sites. The system and method control the quick connection between the loading and unloading arm and the tank truck and the emergency cut-off LNG delivery by specifying the on-off control of the quick connector and the quick cut-off valve, thereby preventing the continuous leakage of LNG and preventing the formation of large-scale combustibles; by monitoring the electrostatic charge of the human body of the personnel in the LNG loading and unloading operation and issuing an alarm when the static charge is large, and even automatically cutting off the loading and unloading pipeline and the liquid / gas phase pipeline of the LNG operation box, the electrostatic discharge of the human body is prevented; by monitoring the human body electrostatic grounding, the tank truck electrostatic grounding detection system and the control system configuration interlock, combined with the loading and unloading site fine water atomization system, the human body static charge in the loading and unloading area is actively prevented and controlled, and the potential charged human body induced leakage of volatile flammable gas explosion accidents are prevented, so as to ensure the personal safety of the loading and unloading operators. The present invention can effectively prevent the occurrence of excessive human body static charge and poor equipment grounding in the LNG loading and unloading operation area, and form corresponding countermeasures, thereby ensuring the safety of on-site operations.

[0086] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any person familiar with the technology within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

[0087] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0088] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0089] It should be understood that the embodiments disclosed in the present invention are not limited to the specific structures, processing steps or materials disclosed herein, but should be extended to equivalent substitutions of these features understood by ordinary technicians in the relevant field. It should also be understood that the terms used herein are only used for the purpose of describing specific embodiments and are not meant to be limiting.

[0090] The "one embodiment" or "embodiment" mentioned in the specification means that the specific features, structures or characteristics described in conjunction with the embodiment are included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment" or "embodiment" appearing in various places throughout the specification do not necessarily refer to the same embodiment.

[0091] Although the embodiments disclosed in the present invention are as above, the contents described are only embodiments adopted for facilitating the understanding of the present invention and are not intended to limit the present invention. Any technician in the technical field to which the present invention belongs can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. An electrostatic safety control system for LNG loading and unloading sites, characterized in that: include: Electrostatic grounding self-detection device, which is used to detect the electrostatic grounding status of the LNG tanker; A human body static electricity monitoring device, which is used to detect the human body static electricity potential of the operator in real time; A control device is used to diagnose whether the tank truck grounding test is qualified according to the electrostatic grounding state, and when the grounding test is qualified, 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 for interrupting the loading and unloading operation for an unsafe operating state.

2. The electrostatic safety control system according to claim 1, characterized in that: The human body static electricity monitoring device is implemented by a non-contact electric field sensor array, which is installed on a clamp or a movable operating column through a connecting line, and the non-contact electric field sensor array is arranged in the working area where the loading and unloading workers are located.

3. The electrostatic safety control system according to claim 2, characterized in that: The non-contact electric field sensors are distributed at the following locations: The end of the loading arm in the loading skid in the LNG loading and unloading site, and the gas and liquid pipeline inlets at the rear end of the tank truck operating box; The universal joint and valves in the loading arm; At each valve in the tank truck operating box.

4. The electrostatic safety control system according to any one of claims 1 to 3, characterized in that: The control device is also used to dynamically diagnose the eligibility of the tank truck grounding detection based on the tank truck-to-ground capacitance value, ground leakage resistance and grounding resistance detected in real time, wherein: When it is detected that the capacitance value of the tank truck to the ground does not reach the preset capacitance threshold, or the leakage resistance to the ground or the grounding resistance exceeds the corresponding preset resistance threshold, a first type of on-off control instruction for controlling the disconnection between the loading skid and the loading arm and a second type of on-off control instruction for controlling the disconnection between the loading arm and the tank truck operating box are output, and an indication warning is issued; When it is detected that the capacitance value of the tank truck to the ground reaches or exceeds the preset capacitance threshold, and both the leakage resistance to the ground and the grounding resistance do not exceed the corresponding preset resistance threshold, an indication information indicating that the electrostatic grounding detection is qualified is output.

5. The electrostatic safety control system according to claim 4, characterized in that: The control device is also used to diagnose whether to start the loading and unloading operation based on the real-time detected human body electrostatic potential and a preset electrostatic potential threshold after obtaining the electrostatic grounding detection qualified indication information, wherein: When it is detected that the electrostatic potential of the human body reaches or exceeds a preset electrostatic potential threshold, a first type on-off control instruction for controlling the loading skid to disconnect from the loading arm is output, and an indication warning is issued; When it is detected that the electrostatic potential of the human body does not reach the preset electrostatic potential threshold, an indication message allowing the loading and unloading operation is output.

6. The electrostatic safety control system according to claim 5, characterized in that: The control device is further used to diagnose the qualified state of the electrostatic potential of the operator during the loading and unloading operation according to the real-time detected electrostatic potential of the human body and using a preset electrostatic potential threshold after obtaining the instruction information allowing the loading and unloading operation, wherein: When it is detected that the electrostatic potential of the human body reaches or exceeds a preset electrostatic potential threshold, a first type of on-off control instruction for controlling the disconnection between the loading skid and the loading arm is output and an indication warning is issued; When it is detected that the electrostatic potential of the human body does not reach the preset electrostatic potential threshold, a first type on-off control instruction is provided for controlling the loading skid to be disconnected from the loading arm after the LNG loading and unloading is completed.

7. The electrostatic safety control system according to claim 5 or 6, characterized in that: The control device is also used to compare the real-time detected human electrostatic potential with a preset potential safety threshold, and diagnose the qualified state of the electrostatic potential of the operator before and after the loading and unloading operation, wherein the potential safety threshold is less than the electrostatic potential threshold, wherein: When it is detected that the electrostatic potential of the human body reaches or exceeds the preset potential safety threshold and does not exceed the preset electrostatic potential threshold, an abnormal alarm message is output to prompt the staff to stay away from the current working area.

8. The electrostatic safety control system according to any one of claims 4 to 7, characterized in that: The first type of on-off control instructions are used to control the on-off state of the loading arm gas phase quick shut-off valve and the loading arm liquid phase quick shut-off valve, which are used to connect the gas phase pipeline interface and the liquid phase pipeline interface on the loading skid to the gas phase arm and the liquid phase arm in the loading arm respectively; The second type of on-off control instructions are used to control the on-off status of the tank truck gas phase pipeline emergency shut-off valve and the tank truck liquid phase pipeline emergency shut-off valve, which are used to connect the gas phase arm and liquid phase arm in the loading arm to the gas phase pipeline interface and liquid phase pipeline interface in the tank truck operating box respectively.

9. The electrostatic safety control system according to claim 6, characterized in that: The electrostatic safety control system also includes: The water drop atomization device is installed on the top of the loading station canopy or the loading skid, and is used to actively perform atomization humidification in the current loading and unloading operation area under the control of the humidification instruction, so that the relative humidity of the loading and unloading operation area is maintained above the 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 also used to generate the humidification instruction and send the humidification instruction to the water drop atomization device when it is detected that the electrostatic potential of the operator during the loading and unloading operation is in an unqualified state.

10. A loading and unloading mechanism for LNG loading and unloading sites, characterized in that: include: The electrostatic safety control system according to any one of claims 1 to 9; A loading arm system of a loading skid in the LNG loading and unloading yard, which is connected to the first end of the electrostatic safety control system; and The LNG tank truck is connected to the second end of the electrostatic safety control system.

11. A static electricity safety control method for LNG loading and unloading sites, characterized in that: The electrostatic safety control method is implemented according to the electrostatic safety control system according to any one of claims 1 to 9, wherein the electrostatic safety control method comprises: The electrostatic grounding self-detection device is used to detect the electrostatic grounding status of the LNG tank truck; The control device diagnoses whether the tank truck grounding test is qualified according to the electrostatic grounding state; The human body static electricity monitoring device is used to detect the human body static electricity potential of the operator in real time; When the grounding detection is qualified, the control device diagnoses whether the electrostatic potential of the operator before and after the loading and unloading operation is in a safe state based on the human body electrostatic potential, and outputs a response control strategy for interrupting the loading and unloading operation for an unsafe operating state.

12. The static electricity safety control method according to claim 11, characterized in that: The human body static electricity monitoring device is implemented by a non-contact electric field sensor array, and the non-contact electric field sensor array is arranged in the working area where the loading and unloading workers are located.

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