Interlocking control system for oil pressure emergency cut-off valve of liquefied petroleum gas storage tank

Abstract

The utility model discloses a liquefied petroleum gas storage tank oil pressure emergency cut-off valve interlocking control system which comprises a storage tank, a hand-operated oil pressure pump, a pressure relief oil return pipeline, a controller, a pressure transmitter, a liquid level transmitter and three electromagnetic three-way valves. The storage tank gas phase pipe, the storage tank liquid outlet pipe and the storage tank liquid inlet pipe are each provided with an oil pressure type emergency cut-off valve, the three electromagnetic three-way valves are correspondingly connected to the three oil pressure type emergency cut-off valves respectively, and three connecting ports of the electromagnetic three-way valves are communicated with the hand-operated oil pressure pump, the pressure relief oil return pipeline and the oil pressure type emergency cut-off valves respectively. Original equipment is utilized to the maximum extent, interlocking control function transformation of the oil pressure type emergency cut-off valve is carried out on the storage tank of the liquefied petroleum gas station, the national new standard requirement and the liquefied petroleum gas station safety management requirement are met, meanwhile, the transformation cost is reduced to the maximum extent, and the transformation period is shortened to the maximum extent.

Description

Technical Field

[0001] The utility model belongs to the technical field of the oil-pressure emergency cut-off system of liquefied petroleum gas stations, and particularly relates to an interlock control system for an oil-pressure emergency cut-off valve of a liquefied petroleum gas storage tank. Background Technique

[0002] In recent years, several serious safety accidents have occurred successively in the domestic liquefied petroleum gas industry, which has attracted the high attention of the state to the safety management of the liquefied petroleum gas industry. The "National Urban Gas Safety Inspection and Rectification Work Plan" issued by the State Council Safety Production Committee; the "Guiding Opinions on Strengthening the Safety Management of Bottled Liquefied Petroleum Gas" jointly issued by six departments including the Ministry of Housing and Urban-Rural Development have put forward clear goals, tasks, progress and requirements for the improvement work of the entire chain of safety management in the liquefied petroleum gas industry. The "Code for Design of Liquefied Petroleum Gas Supply Engineering" GB51142-2015, which came into effect on August 1, 2016, replaced the content of Chapter 8 of the original "Code for Design of Urban Gas" GB50028-2006. Article 9.3.5, Item 3 requires that "emergency cut-off valves shall be installed on the liquid-phase outlet pipe and gas-phase pipe of the storage tank". Article 4.3.3 of the "Code for Gas Engineering Projects" GB55009-2021, which came into effect on January 1, 2022, further stipulates that "emergency cut-off valves interlocked with the liquid-level control of the storage tank shall be installed on the liquid-phase inlet and outlet pipes of liquefied natural gas and liquefied petroleum gas storage tanks".

[0003] For the liquefied petroleum gas stations built previously, oil-pressure emergency cut-off valves are installed on the liquid-phase inlet and outlet pipes and gas-phase pipes of the storage tank, but they do not have the function of control interlock. According to the current specifications, the original valves need to be removed for renovation, replaced with pneumatic valves, and the instrument air pipes need to be re-laid, and air compressors or nitrogen cylinder groups need to be newly installed. Such a renovation method has high costs and a long construction period, and the replaced valve pipes, etc. have no reuse value. Content of the Utility Model

[0004] Aiming at the problems existing in the prior art, the purpose of the utility model is to provide an interlock control system for an oil-pressure emergency cut-off valve of a liquefied petroleum gas storage tank.

[0005] To solve the above problems, the utility model adopts the following technical solutions:

[0006] An interlock control system for an oil-pressure emergency cut-off valve of a liquefied petroleum gas storage tank, comprising a storage tank, a hand-operated oil pump, a pressure relief and oil return pipeline, a controller, a pressure transmitter, a liquid level transmitter and three electromagnetic three-way valves. The storage tank is connected with a storage tank gas-phase pipe, a storage tank liquid outlet pipe and a storage tank liquid inlet pipe. An oil-pressure emergency cut-off valve is provided on each of the storage tank gas-phase pipe, the storage tank liquid outlet pipe and the storage tank liquid inlet pipe. The three electromagnetic three-way valves are respectively connected to the oil-pressure emergency cut-off valves connected to the storage tank gas-phase pipe, the storage tank liquid outlet pipe and the storage tank liquid inlet pipe. The three connection ports of the electromagnetic three-way valve are respectively communicated with the hand-operated oil pump, the pressure relief and oil return pipeline and the oil-pressure emergency cut-off valve. The pressure transmitter is connected to the storage tank and is in signal connection with the controller to monitor the pressure information in the storage tank and convert it into an electrical signal and send it to the controller. The liquid level transmitter is connected to the storage tank and is in signal connection with the controller to monitor the liquid level information of the liquefied petroleum gas in the storage tank and convert it into an electrical signal and send it to the controller. The controller is in signal connection with the three electromagnetic three-way valves to receive the electrical signals sent by the pressure transmitter and the liquid level transmitter, make a judgment, and then respectively control the three electromagnetic three-way valves to connect the oil-pressure emergency cut-off valve with the hand-operated oil pump or the pressure relief and oil return pipeline.

[0007] Preferably, the pressure transmitter is a remote pressure transmitter.

[0008] Preferably, the liquid level transmitter is a remote liquid level transmitter.

[0009] Preferably, when the controller receives the electrical signal sent by the pressure transmitter indicating that the pressure in the storage tank is less than 1.6 Mpa, it controls the electromagnetic three-way valve connected to the oil-pressure emergency cut-off valve on the storage tank gas-phase pipe to connect the oil-pressure emergency cut-off valve with the hand-operated oil pump; when the controller receives the electrical signal sent by the pressure transmitter indicating that the pressure in the storage tank is greater than or equal to 1.6 Mpa, it controls the electromagnetic three-way valve connected to the oil-pressure emergency cut-off valve on the storage tank gas-phase pipe to connect the oil-pressure emergency cut-off valve with the pressure relief and oil return pipeline.

[0010] Preferably, when the controller receives the electrical signal sent by the liquid level transmitter indicating that the liquid level of liquefied petroleum gas in the storage tank is less than 90%, it controls the electromagnetic three-way valve connected to the oil pressure type emergency cut-off valve on the liquid inlet pipe of the storage tank to connect the oil pressure type emergency cut-off valve with the hand-operated oil pump; when the controller receives the electrical signal sent by the liquid level transmitter indicating that the liquid level of liquefied petroleum gas in the storage tank is greater than or equal to 90%, it controls the electromagnetic three-way valve connected to the oil pressure type emergency cut-off valve on the liquid inlet pipe of the storage tank to connect the oil pressure type emergency cut-off valve with the pressure relief and oil return pipeline; when the controller receives the electrical signal sent by the liquid level transmitter indicating that the liquid level of liquefied petroleum gas in the storage tank is greater than 5%, it controls the electromagnetic three-way valve connected to the oil pressure type emergency cut-off valve on the liquid outlet pipe of the storage tank to connect the oil pressure type emergency cut-off valve with the hand-operated oil pump; when the controller receives the electrical signal sent by the liquid level transmitter indicating that the liquid level of liquefied petroleum gas in the storage tank is less than or equal to 5%, it controls the electromagnetic three-way valve connected to the oil pressure type emergency cut-off valve on the liquid outlet pipe of the storage tank to connect the oil pressure type emergency cut-off valve with the pressure relief and oil return pipeline.

[0011] Preferably, an audible and visual alarm is electrically connected to the controller to determine the electrical signals sent by the pressure transmitter and the liquid level transmitter and then control whether the audible and visual alarm alarms.

[0012] Preferably, when the controller receives the electrical signal sent by the pressure transmitter indicating that the pressure in the storage tank is greater than or equal to 1.55 Mpa, it controls the audible and visual alarm to alarm.

[0013] Preferably, when the controller receives the electrical signal sent by the liquid level transmitter indicating that the liquid level of liquefied petroleum gas in the storage tank is greater than or equal to 85%, it controls the audible and visual alarm to alarm.

[0014] Preferably, when the controller receives the electrical signal sent by the liquid level transmitter indicating that the liquid level of liquefied petroleum gas in the storage tank is less than or equal to 10%, it controls the audible and visual alarm to alarm.

[0015] Preferably, the controller is a PLC controller.

[0016] The beneficial effects of the present utility model:

[0017] Compared with the prior art, the advantages of the present utility model are:

[0018] The utility model monitors the liquid level and pressure information of the storage tank in real time through a pressure transmitter and a liquid level transmitter and transmits the information to a controller. The electromagnetic three-way valve is used to connect a hand-operated oil pressure pump, a pressure relief and oil return pipeline, and an oil pressure type emergency cut-off valve. Then, the controller controls the electromagnetic three-way valve connected to the oil pressure type emergency cut-off valve on the gas phase pipe, the liquid outlet pipe, and the liquid inlet pipe of the storage tank according to the liquid level and pressure information of the storage tank to connect the oil pressure type emergency cut-off valve with the hand-operated oil pressure pump or the pressure relief and oil return pipeline, so as to realize the emergency cut-off or pressurization of the oil pressure type emergency cut-off valve, thereby realizing the control interlock of the oil pressure type emergency cut-off valve with the liquid level and pressure of the storage tank. The utility model makes the maximum use of the original equipment, transforms the interlock control function of the oil pressure type emergency cut-off valve for the storage tank of the liquefied petroleum gas station, and while meeting the requirements of the new national standard and the safety management needs of the liquefied petroleum gas station, also considers maximizing the reduction of the transformation cost and shortening the transformation period. Brief Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram of the utility model. Detailed Embodiment

[0020] Next, the technical solutions in the embodiments of the utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only a part of the embodiments of the utility model, rather than all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the utility model.

[0021] In the description of the utility model, it should be noted that the orientation or positional relationship indicated by the terms "upper / lower end", "inside", "outside", "front end", "rear end", "both ends", "one end", "the other end", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0022] In the description of the utility model, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "set / sleeved with", "socketed", "connected", etc. should be understood in a broad sense. For example, "connected" 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 directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the utility model can be understood according to specific situations.

[0023] Please refer to Figure 1 , the present utility model provides a technical solution: a hydraulic emergency cut-off valve interlock control system for a liquefied petroleum gas storage tank, including a storage tank 1, a hand-operated hydraulic pump 3, a pressure relief and oil return pipeline 4, a controller 5, a pressure transmitter 6, a liquid level transmitter 7 and three electromagnetic three-way valves 8. A storage tank gas phase pipe 11, a storage tank liquid outlet pipe 12 and a storage tank liquid inlet pipe 13 are connected to the storage tank 1. An oil pressure type emergency cut-off valve 2 is respectively arranged on the storage tank gas phase pipe 11, the storage tank liquid outlet pipe 12 and the storage tank liquid inlet pipe 13. The three electromagnetic three-way valves 8 are respectively connected to the oil pressure type emergency cut-off valves 2 connected to the storage tank gas phase pipe 11, the storage tank liquid outlet pipe 12 and the storage tank liquid inlet pipe 13. The three connection ports of the electromagnetic three-way valve 8 are respectively communicated with the hand-operated hydraulic pump 3, the pressure relief and oil return pipeline 4 and the oil pressure type emergency cut-off valve 2. The pressure transmitter 6 is connected to the storage tank 1 and is in signal connection with the controller 5 to monitor the pressure information in the storage tank 1 and convert it into an electrical signal and send it to the controller 5. The liquid level transmitter 7 is connected to the storage tank 1 and is in signal connection with the controller 5 to monitor the liquid level information of the liquefied petroleum gas in the storage tank 1 and convert it into an electrical signal and send it to the controller 5. The controller 5 is in signal connection with the three electromagnetic three-way valves 8 to receive the electrical signals sent by the pressure transmitter 6 and the liquid level transmitter 7, make judgments, and respectively control the three electromagnetic three-way valves 8 to communicate the oil pressure type emergency cut-off valve 2 with the hand-operated hydraulic pump 3 or the pressure relief and oil return pipeline 4.

[0024] The present utility model monitors the liquid level and pressure information of the storage tank 1 in real time through the pressure transmitter 6 and the liquid level transmitter 7 and transmits it to the controller 5, and connects the hand-operated hydraulic pump 3, the pressure relief and oil return pipeline 4 and the oil pressure type emergency cut-off valve 2 through the electromagnetic three-way valve 8. Then, the controller 5 respectively controls the electromagnetic three-way valves 8 connected to the oil pressure type emergency cut-off valves 2 on the storage tank gas phase pipe 11, the storage tank liquid outlet pipe 12 and the storage tank liquid inlet pipe 13 to communicate the oil pressure type emergency cut-off valve 2 with the hand-operated hydraulic pump 3 or the pressure relief and oil return pipeline 4 according to the liquid level and pressure information of the storage tank 1, so as to realize the emergency cut-off or pressurization of the oil pressure type emergency cut-off valve 2, and thus realize the control interlock of the oil pressure type emergency cut-off valve 2 with the liquid level and pressure of the storage tank 1. The present utility model makes the best use of the original equipment, transforms the interlock control function of the oil pressure type emergency cut-off valve 2 for the storage tank 1 of the liquefied petroleum gas station. While meeting the requirements of the new national standard and the safety management needs of the liquefied petroleum gas station, it also considers maximizing the reduction of the transformation cost and shortening the transformation period.

[0025] Further, the pressure transmitter 6 is a remote pressure transmitter, and the liquid level transmitter 7 is a remote liquid level transmitter, so as to realize remote control and complete remote interlock.

[0026] Further, when the controller 5 receives an electrical signal sent by the pressure transmitter 6 indicating that the pressure in the storage tank 1 is less than 1.6 Mpa, it controls the electromagnetic three-way valve 8 connected to the oil-pressure emergency cut-off valve 2 on the gas-phase pipe 11 of the storage tank to connect the oil-pressure emergency cut-off valve 2 to the hand-operated oil pump 3, so that the hand-operated oil pump 3 continuously pressurizes the oil-pressure emergency cut-off valve 2 to keep the gas-phase pipe 11 of the storage tank connected; when the controller 5 receives an electrical signal sent by the pressure transmitter 6 indicating that the pressure in the storage tank 1 is greater than or equal to 1.6 Mpa, it controls the electromagnetic three-way valve 8 connected to the oil-pressure emergency cut-off valve 2 on the gas-phase pipe 11 of the storage tank to connect the oil-pressure emergency cut-off valve 2 to the pressure relief and oil return pipeline 4 to urgently cut off the gas-phase pipe 11 of the storage tank.

[0027] Further, when the controller 5 receives an electrical signal sent by the liquid level transmitter 7 indicating that the liquid level of liquefied petroleum gas in the storage tank 1 is less than 90%, it controls the electromagnetic three-way valve 8 connected to the oil-pressure emergency cut-off valve 2 on the liquid inlet pipe 13 of the storage tank to connect the oil-pressure emergency cut-off valve 2 to the hand-operated oil pump 3, so that the hand-operated oil pump 3 continuously pressurizes the oil-pressure emergency cut-off valve 2 to keep the liquid inlet pipe 13 of the storage tank connected; when the controller 5 receives an electrical signal sent by the liquid level transmitter 7 indicating that the liquid level of liquefied petroleum gas in the storage tank 1 is greater than or equal to 90%, it controls the electromagnetic three-way valve 8 connected to the oil-pressure emergency cut-off valve 2 on the liquid inlet pipe 13 of the storage tank to connect the oil-pressure emergency cut-off valve 2 to the pressure relief and oil return pipeline 4 to urgently cut off the liquid inlet pipe 13 of the storage tank and stop the liquid inlet.

[0028] Further, when the controller 5 receives an electrical signal sent by the liquid level transmitter 7 indicating that the liquid level of liquefied petroleum gas in the storage tank 1 is greater than 5%, it controls the electromagnetic three-way valve 8 connected to the oil-pressure emergency cut-off valve 2 on the liquid outlet pipe 12 of the storage tank to connect the oil-pressure emergency cut-off valve 2 to the hand-operated oil pump 3, so that the hand-operated oil pump 3 continuously pressurizes the oil-pressure emergency cut-off valve 2 to keep the liquid outlet pipe 12 of the storage tank connected; when the controller 5 receives an electrical signal sent by the liquid level transmitter 7 indicating that the liquid level of liquefied petroleum gas in the storage tank 1 is less than or equal to 5%, it controls the electromagnetic three-way valve 8 connected to the oil-pressure emergency cut-off valve 2 on the liquid outlet pipe 12 of the storage tank to connect the oil-pressure emergency cut-off valve 2 to the pressure relief and oil return pipeline 4 to urgently cut off the liquid outlet pipe 12 of the storage tank and stop the liquid outlet.

[0029] Further, an audible and visual alarm 9 is electrically connected to the controller 5 to judge the electrical signals sent by the pressure transmitter 6 and the liquid level transmitter 7 and control whether the audible and visual alarm 9 alarms, so as to give an early warning to the operator.

[0030] Further, when the controller 5 receives an electrical signal sent by the pressure transmitter 6 indicating that the pressure in the storage tank 1 is greater than or equal to 1.55 Mpa, it controls the audible and visual alarm 9 to alarm.

[0031] Furthermore, when the controller 5 receives the electrical signal sent by the liquid level transmitter 7 indicating that the liquid level of the liquefied petroleum gas in the storage tank 1 is greater than or equal to 85%, it controls the audible and visual alarm 9 to give an alarm.

[0032] Furthermore, when the controller 5 receives the electrical signal sent by the liquid level transmitter 7 indicating that the liquid level of the liquefied petroleum gas in the storage tank 1 is less than or equal to 10%, it controls the audible and visual alarm 9 to give an alarm.

[0033] Specifically, the controller 5 is a PLC controller.

[0034] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation. An element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0035] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An interlock control system for an oil pressure emergency cut-off valve of a liquefied petroleum gas storage tank, comprising a storage tank (1). A storage tank gas phase pipe (11), a storage tank liquid outlet pipe (12) and a storage tank liquid inlet pipe (13) are communicated with the storage tank (1). An oil pressure type emergency cut-off valve (2) is respectively arranged on the storage tank gas phase pipe (11), the storage tank liquid outlet pipe (12) and the storage tank liquid inlet pipe (13), and is characterized in that, The system further includes a hand-operated oil pressure pump (3), a pressure relief and oil return pipeline (4), a controller (5), a pressure transmitter (6), a liquid level transmitter (7), and three electromagnetic three-way valves (8). The three electromagnetic three-way valves (8) are respectively connected to the oil pressure type emergency cut-off valves (2) connected to the gas phase pipe (11) of the storage tank, the liquid outlet pipe (12) of the storage tank, and the liquid inlet pipe (13) of the storage tank. The three connection ports of the electromagnetic three-way valve (8) are respectively communicated with the hand-operated oil pressure pump (3), the pressure relief and oil return pipeline (4), and the oil pressure type emergency cut-off valve (2). The pressure transmitter (6) is connected to the storage tank (1) and is in signal connection with the controller (5) to monitor the pressure information in the storage tank (1) and convert it into an electrical signal and send it to the controller (5). The liquid level transmitter (7) is connected to the storage tank (1) and is in signal connection with the controller (5) to monitor the liquid level information of the liquefied petroleum gas in the storage tank (1) and convert it into an electrical signal and send it to the controller (5). The controller (5) is in signal connection with the three electromagnetic three-way valves (8) to receive the electrical signals sent by the pressure transmitter (6) and the liquid level transmitter (7), and after judgment, respectively control the three electromagnetic three-way valves (8) to communicate the oil pressure type emergency cut-off valve (2) with the hand-operated oil pressure pump (3) or the pressure relief and oil return pipeline (4).

2. The interlock control system of an oil pressure emergency cut-off valve for a liquefied petroleum gas storage tank according to claim 1, characterized in that, The pressure transmitter (6) is a remote pressure transmitter.

3. The interlock control system of an oil pressure emergency cut-off valve for a liquefied petroleum gas storage tank according to claim 1, characterized in that, The liquid level transmitter (7) is a remote liquid level transmitter.

4. A hydraulic emergency cut-off valve interlock control system for a liquefied petroleum gas storage tank according to claim 1, characterized in that, When the controller (5) receives the electrical signal sent by the pressure transmitter (6) indicating that the pressure in the storage tank (1) is less than 1.6 Mpa, it controls the electromagnetic three-way valve (8) connected to the oil pressure type emergency cut-off valve (2) on the gas phase pipe (11) of the storage tank to communicate the oil pressure type emergency cut-off valve (2) with the hand-operated oil pressure pump (3); When the controller (5) receives the electrical signal sent by the pressure transmitter (6) indicating that the pressure in the storage tank (1) is greater than or equal to 1.6 Mpa, it controls the electromagnetic three-way valve (8) connected to the oil pressure type emergency cut-off valve (2) on the gas phase pipe (11) of the storage tank to communicate the oil pressure type emergency cut-off valve (2) with the pressure relief and oil return pipeline (4).

5. The interlock control system of an oil pressure emergency cut-off valve for a liquefied petroleum gas storage tank according to claim 1, wherein When the controller (5) receives the electrical signal sent by the liquid level transmitter (7) indicating that the liquid level of the liquefied petroleum gas in the storage tank (1) is less than 90%, it controls the electromagnetic three-way valve (8) connected to the oil pressure type emergency cut-off valve (2) on the liquid inlet pipe (13) of the storage tank to communicate the oil pressure type emergency cut-off valve (2) with the hand-operated oil pressure pump (3); When the controller (5) receives the electrical signal sent by the liquid level transmitter (7) indicating that the liquid level of the liquefied petroleum gas in the storage tank (1) is greater than or equal to 90%, it controls the electromagnetic three-way valve (8) connected to the oil pressure type emergency cut-off valve (2) on the liquid inlet pipe (13) of the storage tank to communicate the oil pressure type emergency cut-off valve (2) with the pressure relief and oil return pipeline (4); When the controller (5) receives the electrical signal sent by the liquid level transmitter (7) indicating that the liquid level of the liquefied petroleum gas in the storage tank (1) is greater than 5%, it controls the electromagnetic three-way valve (8) connected to the oil pressure type emergency cut-off valve (2) on the liquid outlet pipe (12) of the storage tank to communicate the oil pressure type emergency cut-off valve (2) with the hand-operated oil pressure pump (3); When the controller (5) receives an electrical signal sent by the liquid level transmitter (7) indicating that the liquid level of liquefied petroleum gas in the storage tank (1) is less than or equal to 5%, it controls the electromagnetic three-way valve (8) connected to the oil pressure type emergency cut-off valve (2) on the liquid discharge pipe (12) of the storage tank to connect the oil pressure type emergency cut-off valve (2) to the pressure relief and oil return pipeline (4).

6. The interlock control system of an oil pressure emergency cut-off valve for a liquefied petroleum gas storage tank according to claim 1, characterized in that, An audible and visual alarm (9) is electrically connected to the controller (5) to determine whether to alarm the audible and visual alarm (9) after judging the electrical signals sent by the pressure transmitter (6) and the liquid level transmitter (7).

7. The interlocking control system of an oil pressure emergency cut-off valve for a liquefied petroleum gas storage tank according to claim 6, characterized in that, When the controller (5) receives an electrical signal sent by the pressure transmitter (6) indicating that the pressure in the storage tank (1) is greater than or equal to 1.55 Mpa, it controls the audible and visual alarm (9) to alarm.

8. An interlock control system for an oil pressure emergency cut-off valve of a liquefied petroleum gas storage tank according to claim 6, characterized in that, When the controller (5) receives an electrical signal sent by the liquid level transmitter (7) indicating that the liquid level of liquefied petroleum gas in the storage tank (1) is greater than or equal to 85%, it controls the audible and visual alarm (9) to alarm.

9. The interlock control system of an oil pressure emergency cut-off valve for a liquefied petroleum gas storage tank according to claim 6, characterized in that, When the controller (5) receives an electrical signal sent by the liquid level transmitter (7) indicating that the liquid level of liquefied petroleum gas in the storage tank (1) is less than or equal to 10%, it controls the audible and visual alarm (9) to alarm.

10. The interlocking control system of an oil pressure emergency cut-off valve for a liquefied petroleum gas storage tank according to claim 1, wherein The controller (5) is a PLC controller.

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