Automatic train loading system suitable for high-solidification-point crude oil and residual oil purging method of automatic train loading system

Abstract

The invention discloses an automatic train loading system suitable for high-solidification-point crude oil and a residual oil purging method thereof.The system comprises a crude oil loading pipeline module, a loading oil gas recovery module and a nitrogen purging module, and the crude oil loading pipeline module is used for crude oil loading; the loading oil gas recovery module is used for recovering oil gas generated in the crude oil loading pipeline module in the crude oil loading process; the nitrogen purging module is used for removing crude oil remaining in the crude oil loading pipeline module in the crude oil loading process. Automatic loading of the whole train is achieved through the crude oil loading pipeline module, the loading oil gas recovery module, the nitrogen purging module and the urgent steam purging blockage removal module. Through linkage of an electric V-shaped regulating valve and an electric ball valve on a crude oil loading pipeline, the problem of insufficient treatment capacity of an oil gas recovery device caused by large air inflow of simultaneous loading of a plurality of trains is solved; the automatic alignment crane pipe on the crude oil loading pipeline is linked with a nitrogen purging module electromagnetic valve to solve the problem that crude oil of the crane pipe adheres to the wall.

Description

Technical Field

[0001] The present invention relates to the technical field of oilfield storage and transportation, and particularly to an automatic train loading system applicable to high pour point crude oil and a method for purging residual oil thereof. Background Art

[0002] Due to the high pour point and high viscosity of high pour point crude oil, wax deposition, wall hanging, blockage and other phenomena exist in the loading arms after the loading operation. Especially in winter, freezing blockage occurs after long-term accumulation, resulting in inability to load. The loading arm adopts a telescopic vertical pipe. After the crude oil adheres to the wall, the vertical pipe cannot droop, resulting in liquid surface loading, which is likely to generate static electricity and cause safety accidents. In addition, there is a problem of crude oil dripping after loading. Especially in windy areas, the oil hanging on the wall of the loading arm cannot drip in time and is scattered into the atmosphere by the wind, which is particularly serious. There are major safety and environmental protection hazards such as fire and explosion and excessive emissions. At present, there is no technology to completely solve the safety and environmental protection problems caused by the loading of high pour point crude oil. Therefore, it is necessary to study a train loading device applicable to high pour point crude oil in combination with the physical properties of crude oil and production characteristics.

[0003] 1. At present, most train loading systems are multi-channel loading (loading multiple oil tank trucks at the same time). When the number of loading arms for simultaneous loading decreases, the loading pump cannot immediately change the flow rate, which is likely to cause the flow rate of other loading arms to be too large and exceed the flow rate for loading, resulting in safety hazards such as overflow of the tank.

[0004] 2. At present, some train loading systems do not set up an oil and gas recovery system. Although some loading oil and gas can be recovered, there is no interlock relationship between the gas phase pipeline and the liquid phase pipeline. If the valves of other loading arm pipelines cannot be closed in time, there will be a situation where the intake volume of the oil and gas recovery device exceeds the limit and cannot be treated up to standard.

[0005] 3. At present, most crude oil train loading systems do not set up a nitrogen purging line. Due to the high viscosity of the oil product, it cannot drip in time after loading, resulting in wax deposition on the inner wall of the loading arm, which in turn affects the loading operation.

[0006] 4. At present, most crude oil train loading systems do not set up an emergency steam purging system. Once the loading arm is blocked by condensation, it cannot be processed on site; the safety risk of disassembling and assembling the loading arm with oil is extremely high.

[0007] 5. At present, many loading systems still adopt manual operation. The labor intensity of workers is high and the on-site operation safety risk is large. This product operates automatically, can reduce the number of personnel, and can ensure loading safety. Summary of the Invention

[0008] The object of the present invention is to provide an automatic train loading system for high pour point crude oil and its residual oil purging method, which is used to solve the problems affecting the loading operation such as wax formation, wall sticking, and blockage of high pour point crude oil; it can reduce the labor intensity of personnel operation and avoid safety risks. It can be widely used in the loading projects of high pour point and high viscosity oil products in oilfield stations and oil depots, and has great significance for safety and environmental protection. To achieve the above object, the present invention provides the following technical solutions:

[0009] An automatic train loading system for high pour point crude oil, characterized in that the system includes a crude oil loading pipeline module, a loading oil and gas recovery module, and a nitrogen purging module, wherein,

[0010] The crude oil loading pipeline module is used for crude oil loading;

[0011] The loading oil and gas recovery module is used to recover the oil and gas generated in the crude oil loading pipeline module during the crude oil loading process;

[0012] The nitrogen purging module is used to remove the crude oil remaining in the crude oil loading pipeline module during the crude oil loading process.

[0013] Further, the crude oil loading pipeline module includes a loading arm, an electric V-ball valve, and a manual ball valve. Among them, the inlet of the manual ball valve is connected to a loading pump through a pipeline; the outlet of the manual ball valve is connected to the inlet of the electric V-ball valve through a pipeline; the outlet of the electric V-ball valve is connected to the inlet of the loading arm through a pipeline; the outlet of the loading arm is connected to the tanker opening through a pipeline.

[0014] Further, the loading arm is an automatic alignment loading arm; the loading arm is provided with a liquid level gauge and a tuning fork liquid level switch.

[0015] Further, the crude oil loading pipeline module is also provided with electric tracing heat, and the electric tracing heat is arranged on the pipeline between the electric V-ball valve and the loading arm.

[0016] Further, the loading oil and gas recovery module includes an electric ball valve, a flame arrester, and a device for recovering oil and gas. Among them, the inlet of the electric ball valve is connected to the outlet of the loading arm through a pipeline;

[0017] The outlet pipeline of the electric ball valve is connected to the inlet of the flame arrester; the outlet of the flame arrester is connected to the device for recovering oil and gas through a pipeline.

[0018] Further, the loading oil and gas recovery module is also provided with electric tracing heat, and the electric tracing heat is arranged on the pipeline between the electric ball valve and the loading arm.

[0019] Further, the nitrogen purging module includes a manual ball valve, a solenoid valve, and a check valve, wherein,

[0020] The inlet of the manual ball valve is connected to a nitrogen tank through a pipeline, and is used to control the nitrogen purging pressure;

[0021] The outlet pipeline of the manual ball valve is connected to the inlet of the solenoid valve; the outlet pipeline of the solenoid valve is connected to the inlet pipeline of the check valve; the outlet of the check valve is connected to the loading arm through a pipeline.

[0022] Further, the electric V-type regulating valve and the electric ball valve are interlocked through a DCS system; wherein, the electric V-type regulating valve and the electric ball valve are opened or closed simultaneously.

[0023] Further, the system further includes an emergency steam purging and blockage removal module,

[0024] The emergency steam purging and blockage removal module is used to remove the residual crude oil in the crude oil loading pipeline module.

[0025] Further, the emergency steam purging and blockage removal system includes a ball valve and a metal hose; the inlet of the ball valve is connected to the steam pipeline;

[0026] The outlet of the ball valve is connected to the inlet of the metal hose, and the outlet of the metal hose is connected to the loading arm.

[0027] Further, the method includes the following steps: after the electric V-type regulating valve of the liquid-phase pipeline is closed, the loading arm is automatically lifted. When the loading arm nozzle is higher than the crude oil liquid level in the tank car, the signal is fed back to the solenoid valve through the DCS, the solenoid valve is opened, and nitrogen purging is carried out for a predetermined time. After the purging is completed, the solenoid valve is closed, and the loading arm is completely lifted away from the oil tank.

[0028] Further, the method further includes: when the crude oil coagulates and blocks the pipeline, the emergency steam purging and blockage removal system is used for steam purging and blockage removal, and the steps are as follows:

[0029] Connect the steam pipeline to the steam purging port with a hose, open the ball valve, steam enters the crude oil pipeline for purging, and after a predetermined time, the crude oil melts and flows out from the loading arm nozzle;

[0030] When crude oil flows out from the loading arm nozzle, close the ball valve, and the pipeline blockage removal is completed.

[0031] The present invention also provides an application of the automatic train loading system for high pour point crude oil as described above in oilfield stations and oil storage depots transported by trains.

[0032] The technical effects and advantages of the present invention:

[0033] 1. Nitrogen purging can ensure that the wall-hanging crude oil is purged into the tank car, avoiding blockage of the pipeline due to long-term accumulation.

[0034] 2. The steam purging function is an emergency measure. When the pipeline is frozen and blocked due to abnormal working conditions, the heat of the steam is used to remove the blockage of the pipeline.

[0035] 3. The electric V-type regulating valve of the liquid phase pipeline is interlocked with the oil and gas electric ball valve to realize the normal operation of the rear-end oil and gas recovery device.

[0036] The present invention realizes automatic loading of the entire train through a crude oil loading pipeline module, a loading oil and gas recovery module, a nitrogen purge module and a rapid steam purge unblocking module. The electric V-shaped regulating valve on the crude oil loading pipeline and the electric ball valve of the loading oil and gas recovery module are linked to solve the problem of insufficient processing capacity of the oil and gas recovery device caused by the large air intake of multiple trains loading at the same time. The automatic alignment crane pipe on the crude oil loading pipeline and the solenoid valve of the nitrogen purge system are linked to solve the problem of crude oil sticking to the crane pipe wall.

[0037] Other features and advantages of the present invention will be described in the following description, and partly become obvious from the description, or be understood by implementing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The figure is a schematic diagram of the automatic train loading system applicable to high-freezing point crude oil according to the present invention.

[0039] In the figure: 1. crane pipe, 2. electric ball valve, 3. flame arrester, 4. electric heating, 5. ball valve, 6. quick connector, 7. check valve, 8. solenoid valve, 9. ball valve, 10. electric V-type regulating valve, 11. ball valve. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] In order to solve the deficiencies of the prior art, the present invention discloses an automatic train loading system suitable for high-freezing crude oil, such as Figure 1 As shown, the system includes a crude oil loading pipeline module, a loading oil gas recovery module, a nitrogen purge module and a rapid steam purge and unblocking module.

[0042] The crude oil loading pipeline module is used for loading crude oil. In a specific embodiment of the present invention, the crude oil loading pipeline module includes a loading arm 1, an electric V-ball valve 10, and a manual ball valve 11. Among them, the inlet of the manual ball valve 11 is connected to the loading pump through a pipeline; the outlet of the manual ball valve 11 is connected to the inlet of the electric V-ball valve 10 through a pipeline; the outlet of the electric V-ball valve 10 is connected to the inlet of the loading arm 1 through a pipeline; the outlet of the loading arm 1 is connected to the tanker opening through a pipeline. The crude oil loading pipeline module is also provided with electric tracing 4, and the electric tracing 4 is arranged on the pipeline between the electric V-ball valve 10 and the loading arm 1. The purpose of the electric tracing is to maintain the pipeline temperature to ensure that the crude oil in the pipeline does not coagulate and has fluidity.

[0043] In a specific embodiment of the present invention, the loading arm is an automatic alignment loading arm, which can realize logical control; the loading arm is provided with a liquid level gauge and a tuning fork liquid level switch to ensure that the loading does not overflow the tank.

[0044] In a specific embodiment of the present invention, the loading oil and gas recovery module is used to recover the oil and gas generated in the crude oil loading pipeline module during the crude oil loading process. The loading oil and gas recovery module includes an electric ball valve 2, a flame arrester 3, and a device for sending oil and gas to the recovery unit. Among them, the inlet of the electric ball valve 2 is connected to the outlet of the loading arm 1 through a pipeline; the outlet pipeline of the electric ball valve 2 is connected to the inlet of the flame arrester 3; the outlet of the flame arrester 3 is connected to the device for sending oil and gas to the recovery unit through a pipeline. The loading oil and gas recovery module is also provided with electric tracing, and the electric tracing is arranged on the pipeline between the electric ball valve 2 and the loading arm 1. The flame arrester adopts a detonation type flame arrester.

[0045] In a specific embodiment of the present invention, the nitrogen purging module is used to remove the crude oil remaining in the crude oil loading pipeline module during the crude oil loading process.

[0046] The nitrogen purging module includes a manual ball valve 9, a solenoid valve 8, and a check valve 7. Among them, the incoming gas pipeline from the nitrogen tank is connected to the inlet of the manual ball valve 9 to control the nitrogen pressure. Among them, when the opening of the ball valve decreases, the nitrogen volume can be reduced, that is, the nitrogen pressure can be reduced; when the valve opening increases, the nitrogen volume can be increased, that is, the nitrogen pressure can be increased; the outlet pipeline of the manual ball valve 9 is connected to the inlet of the solenoid valve 8. The solenoid valve of the nitrogen pipeline is automatically controlled and automatically opened through the DCS control system to realize automatic purging; the outlet pipeline of the solenoid valve 8 is connected to the inlet pipeline of the check valve 7 to realize the anti-backflow function; the outlet of the check valve 7 is connected to the loading arm 1 through a pipeline.

[0047] In a specific embodiment of the present invention, the emergency steam purging and plugging removal module is used to remove the residual crude oil in the crude oil loading pipeline module. The emergency steam purging and plugging removal system includes a ball valve 5 and a metal hose 6; the inlet of the ball valve 5 is connected to the steam pipeline; the outlet of the ball valve is connected to the inlet of the metal hose 6, and the outlet of the metal hose 6 is connected to the loading arm 1.

[0048] In a specific embodiment of the present invention, the electric V-type regulating valve 10 and the electric ball valve 2 are interlocked through a DCS system (distributed control system); wherein, the electric V-type regulating valve 10 and the electric ball valve 2 are opened or closed simultaneously. Specifically, the signals of the electric V-type regulating valve 10 in the crude oil loading pipeline module and the electric ball valve 2 in the loading and unloading oil and gas recovery module are uniformly uploaded to the DCS system for interlocking (HS); when the electric V-type regulating valve 10 in the crude oil loading pipeline system is opened, the electric ball valve 2 in the loading and unloading oil and gas recovery system is opened; when the electric V-type regulating valve 10 in the crude oil loading pipeline system is closed, the electric ball valve 2 in the loading and unloading oil and gas recovery module is closed.

[0049] Figure 1 Herein, PLC represents a programmable logic controller, MOV represents an electric valve, HS represents interlocking, LS represents liquid level alarm interlock, S represents a solenoid valve, EA represents alarm, ES represents emergency stop, M represents electric, and I represents an interlocking control line. Among them, the interlocking relationship of two valves is set in the system to achieve simultaneous opening and closing: when the electric V-type regulating valve 10 in the liquid phase pipeline is opened, the electric ball valve 2 in the oil and gas pipeline is opened; when the electric V-type regulating valve 10 in the liquid phase pipeline is closed, the electric ball valve 2 in the oil and gas pipeline is closed. When the electric V-type regulating valve 10 receives a start signal, the distributed control system will send opening signals to both the electric ball valve 2 and the electric V-type regulating valve 10 simultaneously. The electric V-type regulating valve 10 is a valve for controlling the liquid (crude oil) pipeline, and the electric ball valve 2 is a pipeline for the oil and gas generated during the crude oil loading process. It is required that the liquid phase pipeline and the oil and gas pipeline be opened and closed simultaneously. It is controlled through a DCS system (distributed control system).

[0050] The overall control of the oil pipe purging process is carried out through a PLC (programmable logic controller). The electric V-type regulating valve 10 and the electric ball valve 2 are interlocked through a DCS system (distributed control system) for HS (interlocking); the liquid level alarm interlock LS and the electric V-type regulating valve 10 are interlocked through a PLC (programmable logic controller) for HS (interlocking); when the oil tanker reaches the liquid level, the electric V-type regulating valve 10 is interlocked and shut off.

[0051] The EA - alarm, ES - emergency stop and the electric V-type regulating valve 10 are interlocked through a PLC (programmable logic controller) for HS (interlocking); when the on-site static electricity grounding fails, a combustible gas alarm or a fire occurs, the system gives an alarm EA and an emergency stop ES, and closes the electric V-type regulating valve 10.

[0052] The present invention is applicable to an automatic train loading system for high - pour crude oil. Through the crude oil loading pipeline module, the loading oil and gas recovery module, the nitrogen purging residual oil module and the emergency steam purging and plug - removing module, the automatic loading of a whole train is realized. It is used to solve the problems such as wax formation, wall sticking, blockage, etc. of high - pour crude oil that affect the loading operation; it can reduce the labor intensity of personnel operation and avoid safety risks, and can be widely promoted and used in the loading projects of high - pour and high - viscosity oil products in oilfield stations and oil depots, having great significance for safety and environmental protection.

[0053] The present invention also provides a method for purging residual oil of an automatic train loading system applicable to high - pour crude oil. The method includes the following steps:

[0054] After the electric V - type regulating valve 10 finishes the shut - off task, the loading arm 1 automatically lifts and stops after leaving the liquid level of the oil tanker, and then starts to purge the loading arm with nitrogen for 30 s. After 30 s, the solenoid valve executes the shut - off task.

[0055] After the electric V - type regulating valve 10 of the liquid - phase pipeline is closed, the manual ball valve 9 is opened, and the loading arm 1 automatically lifts. At this time, there is crude oil hanging on the wall of the loading arm. When the mouth of the loading arm is higher than the liquid level of the crude oil in the tanker, the signal is fed back to the solenoid valve 8 through the DCS, and the solenoid valve 8 is opened to conduct nitrogen purging for 30 s (the purging time can be adjusted within the control system). After the purging is completed, the solenoid valve 8 is closed, and the loading arm completely lifts and leaves the oil tanker. The time can be set in the control system, generally between 30 s and 90 s.

[0056] The method further includes:

[0057] The present invention solves the problem of insufficient processing capacity of the oil and gas recovery device caused by a large intake of gas during the simultaneous loading of multiple trains through the linkage of the electric V - type regulating valve on the crude oil loading pipeline and the electric ball valve of the loading oil and gas recovery system. The automatic alignment loading arm on the crude oil loading pipeline and the solenoid valve of the nitrogen purging system are linked to solve the problem of crude oil sticking to the wall of the loading arm.

[0058] When the pipeline is blocked due to the extremely cold weather and the train electric tracing system fails, and there is crude oil in the pipeline, the crude oil will condense and block the pipeline due to the temperature drop. At this time, steam purging is required to remove the blockage. The operation steps are as follows:

[0059] 1. Connect the steam pipeline to the steam purging port of the loading arm 1 through the hose 6, and slowly open the steam control valve. Steam enters the crude oil pipeline. After a period of time, the crude oil melts and flows out from the mouth of the loading arm 1;

[0060] 2. When crude oil flows out from the mouth of the loading arm, it proves the success of pipeline blockage removal. Close the ball valve 5 to stop purging, and remove the hose 6.

[0061] The present invention also provides the application of an automatic train loading system applicable to high - pour crude oil in oilfield stations and oil storage depots transported by trains.

[0062] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An automatic train loading system applicable to highly viscous crude oil, characterized in that, The system includes a crude oil loading pipeline module, a loading oil and gas recovery module, and a nitrogen purging module. Among them, The crude oil loading pipeline module is used for loading crude oil; The loading oil and gas recovery module is used to recover the oil and gas generated in the crude oil loading pipeline module during the crude oil loading process; The nitrogen purging module is used to remove the crude oil remaining in the crude oil loading pipeline module during the crude oil loading process.

2. The automatic train loading system for highly viscous crude oil according to claim 1, wherein The crude oil loading pipeline module includes a loading arm (1), an electric V-ball valve (10), and a manual ball valve (11). Among them, The inlet of the manual ball valve (11) is used to be connected to a loading pump through a pipeline; The outlet of the manual ball valve (11) is connected to the inlet of the electric V-ball valve (10) through a pipeline; the outlet of the electric V-ball valve (10) is connected to the inlet of the loading arm (1) through a pipeline; The outlet of the loading arm (1) is used to be connected to the tanker opening through a pipeline.

3. The automatic train loading system for high pour point crude oil according to claim 2, characterized in that The loading arm is an automatic alignment loading arm; The loading arm is provided with a liquid level gauge and a tuning fork liquid level switch.

4. The automatic train loading system for high pour point crude oil according to claim 2, characterized in that The crude oil loading pipeline module is further provided with electric tracing (4), and the electric tracing (4) is arranged on the pipeline between the electric V-ball valve (10) and the loading arm (1).

5. The automatic train loading system for high pour point crude oil according to claim 2, characterized in that The loading oil and gas recovery module includes an electric ball valve (2), a flame arrester (3), and a device for recovering oil and gas. Among them, The inlet of the electric ball valve (2) is connected to the outlet of the loading arm through a pipeline; The outlet pipeline of the electric ball valve (2) is connected to the inlet of the flame arrester (3); the outlet of the flame arrester (3) is connected to the device for recovering oil and gas through a pipeline.

6. The automatic train loading system for high pour point crude oil according to claim 5, characterized in that The loading oil and gas recovery module is further provided with electric tracing, and the electric tracing is arranged on the pipeline between the electric ball valve (2) and the loading arm (1).

7. The automatic train loading system for high pour point crude oil according to claim 1, characterized in that The nitrogen purging module includes a manual ball valve (9), a solenoid valve (8), and a check valve (7). Among them, The inlet of the manual ball valve (9) is connected to a nitrogen tank through a pipeline and is used to control the nitrogen purging pressure; The outlet pipeline of the manual ball valve (9) is connected to the inlet of the solenoid valve (8); the outlet pipeline of the solenoid valve (8) is connected to the inlet pipeline of the check valve (7); the outlet of the check valve (7) is connected to the loading arm (1) through a pipeline.

8. The automatic train loading system for high pour point crude oil according to claim 5, characterized in that The electric V-ball valve (10) and the electric ball valve (2) are interlocked through a DCS system; Among them, the electric V-ball valve (10) and the electric ball valve (2) are opened or closed simultaneously.

9. An automatic train loading system for highly viscous crude oil according to claim 4, characterized in that, The system further includes an emergency steam purging and plugging removal module. The emergency steam purging and blockage removal module is used to remove the residual crude oil in the crude oil loading pipeline module.

10. An automatic train loading system for high pour point crude oil according to claim 9, characterized in that The emergency steam purging and blockage removal system includes a ball valve (5) and a metal hose (6); The inlet of the ball valve (5) is connected to the steam pipeline; The outlet of the ball valve is connected to the inlet of the metal hose (6), and the outlet of the metal hose (6) is connected to the loading arm (1).

11. The method for purging residual oil of the automatic train loading system applicable to highly viscous crude oil according to any one of claims 1-10, characterized in that, The method includes the following steps: After the electric V-type regulating valve (10) of the liquid phase pipeline is closed, the loading arm (1) is automatically lifted. When the loading arm nozzle is higher than the crude oil liquid level in the tank car, the signal is fed back to the solenoid valve (8) through the DCS, and the solenoid valve (8) is opened to perform nitrogen purging for a predetermined time. After the purging is completed, the solenoid valve (8) is closed, and the loading arm (1) is completely lifted away from the oil tank.

12. The method for purging residual oil of the automatic train loading system applicable to highly viscous crude oil according to any one of claims 1-10, characterized in that, The method further includes: When the crude oil solidifies and blocks the pipeline, the emergency steam purging and blockage removal system is used for steam purging and blockage removal. The steps are as follows: Connect the steam pipeline to the steam purging port with a hose (6), open the ball valve (5), and steam enters the crude oil pipeline for purging. After a predetermined time, the crude oil melts and flows out from the loading arm nozzle; When crude oil flows out from the loading arm nozzle, close the ball valve (5), and the pipeline blockage removal is completed.

13. Application of the automatic train loading system for high pour point crude oil according to any one of claims 1-10 in oilfield stations and oil storage depots transported by trains.

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