An apparatus and method for controlling the position of slugging during shutdown of a refined oil pipeline

Abstract

The present invention relates to a device and a control method for controlling the position of mixed oil during pipeline shutdown in a refined oil pipeline, including an oil transportation station and a mixed oil shutdown area; the oil transportation station includes an oil storage tank, the oil storage tank is communicated with the refined oil pipeline through a connecting pipe, a first valve is arranged on the connecting pipe, and a second valve is installed on the refined oil pipeline downstream of the connection between the connecting pipe and the refined oil pipeline; the mixed oil shutdown area includes a front diesel and rear gasoline shutdown pipe, an intermediate pipe and a front gasoline and rear diesel shutdown pipe which are sequentially connected to the refined oil pipeline, and the front diesel and rear gasoline shutdown pipe and the front gasoline and rear diesel shutdown pipe are inclined, a first densitometer is installed upstream of the front diesel and rear gasoline shutdown pipe, a second densitometer is installed on the intermediate pipe, and a third densitometer is installed downstream of the front gasoline and rear diesel shutdown pipe. The present invention reduces the amount of mixed oil during pipeline transportation and improves the efficiency of the transported oil products.

Description

Technical Field

[0001] The present invention relates to the technical field of mixed oil treatment for oil pipelines, and in particular to a device and a control method for controlling the stopping position of mixed oil in a refined oil pipeline. Background Art

[0002] Long-distance refined oil pipelines generally adopt the sequential transportation method of alternating gasoline and diesel. During the transportation process, a section of mixed oil will be generated at the interface between gasoline and diesel transportation. Moreover, the longer the transportation distance, the greater the amount of mixed oil generated. The mixed oil section is expressed as the content range of one kind of oil in another kind of oil from 1% to 99%. The mixed oil section enters the mixed oil tank through on-line cutting at the pipeline terminal station, and the subsequent oil products are delivered for trade at the station exit.

[0003] In order to reduce the impact of mixed oil on the quality of pipeline-transported oil products, it is necessary to control the amount of mixed oil generated during sequential transportation. At present, in China, the amount of mixed oil generated during pipeline transportation is generally controlled by optimizing batches and process flows. For the amount of mixed oil generated during the transportation of different oil product batches in a specific pipeline, it is generally within a certain range value. In order to reduce the proportion of mixed oil generated, pipeline management parties usually adopt the method of increasing the single-batch oil transportation volume. In addition, during the transportation process, increasing the flow rate control and reducing the number of stops can avoid the increase in the amount of mixed oil. However, the above mixed oil control methods are only passive measures and cannot fundamentally reduce the amount of mixed oil.

[0004] Chinese Patent CN101788466B discloses "a method for detecting the mixed oil interface in refined oil pipeline transportation", which includes continuously collecting oil samples in the refined oil pipeline at a certain time interval, measuring the absorbance Ai at a wavelength of 904.8 - 907.8 nm by near-infrared spectroscopy, and performing differential spectrum calculation with the near-infrared absorbance A0 measured by n-pentane within the above wavelength range. The differential spectrum value Ri is A0 - Ai, and the mixed oil interface is judged by the Ri value. This invention can monitor the mixed oil interface of pipeline-transported oil products in real time, perform mixed oil cutting in a timely manner, and ensure the quality of pipeline-transported oil products. However, this invention can only monitor and track the mixed oil interface and cannot control the stopping position of the mixed oil.

[0005] Therefore, those skilled in the art are committed to developing a device and a control method for controlling the stopping position of mixed oil in a refined oil pipeline to reduce the amount of mixed oil during pipeline transportation and improve the efficiency of pipeline-transported oil products. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a device and a control method for controlling the stopping position of mixed oil in a refined oil pipeline to reduce the amount of mixed oil during pipeline transportation and improve the efficiency of pipeline-transported oil products.

[0007] The technical solution of the present invention for solving the above technical problem is as follows: A device for controlling the stopping position of mixed oil in a refined oil pipeline includes an oil transportation station yard and a mixed oil stopping and transportation area;

[0008] The oil delivery station includes an oil storage tank, which is communicated with a refined oil pipeline through a connecting pipe. A first valve is arranged on the connecting pipe, and a second valve is installed on the refined oil pipeline downstream of the connection between the connecting pipe and the refined oil pipeline.

[0009] The mixed oil shutdown area includes a front-diesel-back-gasoline shutdown pipe, an intermediate pipe, and a front-gasoline-back-diesel shutdown pipe that are sequentially connected to the refined oil pipeline. The front-diesel-back-gasoline shutdown pipe and the front-gasoline-back-diesel shutdown pipe are inclined. A first densitometer is installed upstream of the front-diesel-back-gasoline shutdown pipe, a second densitometer is installed on the intermediate pipe, and a third densitometer is installed downstream of the front-gasoline-back-diesel shutdown pipe.

[0010] The beneficial effects of the present invention are as follows: By detecting with each densitometer and controlling each valve in a certain order, when the refined oil pipeline sequentially transports oil products, the mixed oil during planned shutdown is stopped in the mixed oil control area through the control system, and the mixed oil volume is reduced by using the density difference and elevation difference. The present invention can be applied to the control of the mixed oil volume during the transportation of diesel and gasoline in the refined oil pipeline, providing technical support for the quality control of pipeline-transported oil products.

[0011] On the basis of the above technical solution, the present invention can also be improved as follows.

[0012] Further, it further includes a control device, which is electrically connected to the first valve, the second valve, the first densitometer, the second densitometer, and the third densitometer.

[0013] The beneficial effect of adopting the above further solution is that the control device is used to control the actions of each component according to the control signal, improving the operation efficiency.

[0014] Further, the angles between the front-diesel-back-gasoline shutdown pipe and the front-gasoline-back-diesel shutdown pipe and the horizontal plane are both greater than 15°.

[0015] The beneficial effect of adopting the above further solution is that there is a certain angle between the front-diesel-back-gasoline shutdown pipe and the front-gasoline-back-diesel shutdown pipe and the horizontal plane, which is beneficial to the stratification of diesel and gasoline.

[0016] The present invention also provides a method for controlling the mixed oil shutdown position of a refined oil pipeline, including the above-mentioned device for controlling the mixed oil shutdown position of a refined oil pipeline, and comprising the following steps:

[0017] S1. According to the shutdown plan of the refined oil pipeline, estimate the mixed oil shutdown position and the mixed oil volume;

[0018] S2. When the forward oil product of the mixed oil is diesel and the backward oil product is gasoline, when the value of the first densitometer starts to decrease, open the first valve and turn down the second valve;

[0019] When the density of the first densitometer is consistent with the density of the pipeline gasoline batch, and the values of the second and third densitometers are both consistent with the pipeline diesel batch, close the second valve;

[0020] S3. When the mixed oil is moving forward with gasoline and backward with diesel, when the value of the second densitometer starts to rise, open the first valve and reduce the second valve;

[0021] When the values of the first and second densitometers are both consistent with the pipeline diesel batch, and the third densitometer is consistent with the gasoline batch density, close the second valve.

[0022] The beneficial effect of adopting the above further solution is to judge the refined oil through the change of the densitometer value, which is conducive to opening and closing different valves.

[0023] Further, in step S2, after the second valve is completely closed, confirm the values of the first and second densitometers again. If the value of the second densitometer becomes smaller, open the first and second valves for reverse transportation until the values of the second and third densitometers are both consistent with the pipeline diesel batch, then close the first and second valves;

[0024] If the value of the first densitometer becomes larger, open the second valve until the first densitometer is consistent with the pipeline gasoline batch and then close the second valve.

[0025] The beneficial effect of adopting the above further solution is to further reduce the content of mixed oil in the mixed oil area through forward or reverse oil transportation.

[0026] Further, in step S3, after the second valve is completely closed, confirm the values of the second and third densitometers again. If the value of the third densitometer becomes larger, open the first and second valves for reverse transportation until the value of the third densitometer is consistent with the pipeline gasoline batch, then close the first and second valves;

[0027] If the value of the second densitometer becomes smaller, open the second valve until the second densitometer is consistent with the pipeline diesel batch and then close the second valve.

[0028] Further, the capacities of the front-diesel-rear-gasoline stop pipeline and the front-gasoline-rear-diesel stop pipeline are 5 to 10 times the amount of mixed oil.

[0029] The beneficial effect of adopting the above further solution is that the capacities of the front-diesel-rear-gasoline stop pipeline and the front-gasoline-rear-diesel stop pipeline are relatively large, which is conducive to the stratification of gasoline and diesel. Brief Description of the Drawings

[0030] Figure 1 It is a schematic structural diagram of a specific embodiment of the present invention;

[0031] Figure 2Schematic diagram of the steps in a specific embodiment of the present invention.

[0032] In the accompanying drawings, the list of components represented by each reference numeral is as follows:

[0033] 1. Oil transportation station; 2. Mixed oil shutdown area; 3. Control device; 4. Storage oil tank; 5. Connecting pipe; 6. Finished product oil pipeline; 7. First valve; 8. Second valve; 9. Front diesel and rear gasoline shutdown pipe; 10. Intermediate pipe; 11. Front gasoline and rear diesel shutdown pipe; 12. First densitometer; 13. Second densitometer; 14. Third densitometer. Specific embodiments

[0034] The principles and features of the present invention will be described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0035] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "length", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "inner", "outer", "peripheral side", "circumferential direction", etc. are based on the orientation or positional relationships shown in the accompanying drawings. These are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the system or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0036] In the description of the present invention, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0037] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; 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 or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] As Figure 1 shown, a control device for the shutdown position of mixed oil in a finished product oil pipeline includes an oil transportation station 1 and a mixed oil shutdown area 2. Specifically, the oil transportation station 1 includes a storage oil tank 4, and multiple storage oil tanks 4 can be provided, which are divided into gasoline storage tanks and diesel storage tanks. The storage oil tank 4 is communicated with the finished product oil pipeline 6 through a connecting pipe 5, and a first valve 7 is provided on the connecting pipe 5. A second valve 8 is installed on the finished product oil pipeline 6 downstream of the connection between the connecting pipe 5 and the finished product oil pipeline 6. Both the first valve 7 and the second valve 8 are electrically controlled valves, which are conducive to remote control.

[0039] The mixed oil shutdown area 2 includes a front-diesel-rear-gasoline shutdown pipe 9, an intermediate pipe 10, and a front-gasoline-rear-diesel shutdown pipe 11 that are sequentially connected to the refined oil pipeline 6, and the front-diesel-rear-gasoline shutdown pipe 9 and the front-gasoline-rear-diesel shutdown pipe 11 are inclined. The front-diesel-rear-gasoline shutdown pipe 9, the intermediate pipe 10, and the front-gasoline-rear-diesel shutdown pipe 11 are generally U-shaped. In some embodiments, in order to facilitate the rapid stratification of diesel and gasoline, the angles between the front-diesel-rear-gasoline shutdown pipe 9 and the front-gasoline-rear-diesel shutdown pipe 11 and the horizontal plane are both greater than 15°. A first densitometer 12 is installed upstream of the front-diesel-rear-gasoline shutdown pipe 9, a second densitometer 13 is installed on the intermediate pipe 10, and a third densitometer 14 is installed downstream of the front-gasoline-rear-diesel shutdown pipe 11.

[0040] In a specific embodiment, it further includes a control device 3, and the control device 3 is electrically connected to the first valve 7, the second valve 8, the first densitometer 12, the second densitometer 13, and the third densitometer 14. The control device 3 receives control signals and controls each valve and each densitometer according to the control signals.

[0041] As Figure 2 shown, the present invention also provides a method for controlling the mixed oil shutdown position of a refined oil pipeline, including the above-mentioned control device for the mixed oil shutdown position of a refined oil pipeline, and includes the following steps:

[0042] S1. According to the shutdown plan of the refined oil pipeline 6, estimate the mixed oil shutdown position and the amount of mixed oil. Specifically, estimating the shutdown position facilitates the operator to observe each densitometer in a timely manner and make corresponding judgments quickly, and the estimated amount of mixed oil is used for the subsequent pipeline design of the mixed oil area.

[0043] S2. When the advancing oil of the mixed oil is diesel and the trailing oil is gasoline, when the value of the first densitometer 12 starts to decrease, open the first valve 7 and turn down the second valve 8;

[0044] When the first densitometer 12 is consistent with the density of the pipeline-transported gasoline batch, and the values of the second densitometer 13 and the third densitometer 14 are both consistent with the density of the pipeline-transported diesel batch, close the second valve 8;

[0045] After the second valve 8 is completely closed, confirm the values of the first densitometer 12 and the second densitometer 13 again. If the value of the second densitometer 13 decreases, open the first valve 7 and the second valve 8 for reverse transportation until the values of the second densitometer 13 and the third densitometer 14 are both consistent with the density of the pipeline-transported diesel batch, then close the first valve 7 and the second valve 8;

[0046] If the value of the first densitometer 12 increases, open the second valve 8 until the value of the first densitometer 12 is consistent with the density of the pipeline-transported gasoline batch, then close the second valve 8.

[0047] Specifically, ① closely monitor the value of the first densitometer 12. When the density value displayed by the first densitometer 12 starts to decline, at this time, the mixed oil head passes through the pipeline position where the first densitometer 12 is located. Meanwhile, open the first valve 7 through the control device 3 and reduce the opening of the second valve 8 to lower the operation speed of the outbound oil product.

[0048] ② When the density value displayed by the first densitometer 12 stabilizes and is consistent with the density of the pipeline gasoline batch, and the density values displayed by the second densitometer 13 and the third densitometer 14 are consistent with the density of the pipeline diesel batch, close the second valve 8 through the control device 3, and the subsequent inbound oil product flows into the storage tank 4.

[0049] ③ After the second valve 8 is completely closed, confirm the density values of the first densitometer 12 and the second densitometer 13 again. If there is no change, the mixed oil stops being transported in the front diesel and rear gasoline stop - transport pipe 9. If the density value displayed by the second densitometer 13 becomes smaller, indicating that part of the mixed oil bypasses the low point, then it is necessary to open the first valve 7 and the second valve 8 through the control device 3 for reverse transportation operation. When the density value displayed by the second densitometer 13 returns to the density of the pipeline diesel batch and the density value displayed by the first densitometer 12 is the density of the pipeline gasoline batch, close the first valve 7 and the second valve 8 through the control device 3.

[0050] If the density value displayed by the first densitometer 12 becomes larger, indicating that part of the mixed oil flows back to the position where the first densitometer 12 is located, then it is necessary to open the second valve 8 through the control device 3 and continue to transport the oil product towards the outbound pipeline direction until the density value of the first densitometer 12 returns to the density of the pipeline gasoline batch and the density value displayed by the second densitometer 13 is the density of the pipeline diesel batch, then close the second valve 8 through the control device 3.

[0051] S3. When the forward - flowing oil product of the mixed oil is gasoline and the backward - flowing oil product is diesel, when the value of the second densitometer 13 starts to rise, open the first valve 7 and reduce the opening of the second valve 8;

[0052] When the values of both the first densitometer 12 and the second densitometer 13 are consistent with the density of the pipeline diesel batch and the third densitometer 14 is consistent with the density of the gasoline batch, close the second valve 8.

[0053] After the second valve 8 is completely closed, confirm the values of the second densitometer 13 and the third densitometer 14 again. If the value of the third densitometer 14 becomes larger, open the first valve 7 and the second valve 8 for reverse transportation until the value of the third densitometer 14 is consistent with the density of the pipeline gasoline batch, then close the first valve 7 and the second valve 8;

[0054] If the value of the second densitometer 13 becomes smaller, open the second valve 8 until the value of the second densitometer 13 is consistent with the density of the pipeline diesel batch, then close the second valve 8.

[0055] Specifically, ① closely monitor the value of the second densitometer 13. When the density value displayed by the second densitometer 13 starts to rise, at this time, the mixed oil head passes through the pipeline position where the second densitometer 13 is located. At the same time, open the first valve 7 through the control device 3 and turn down the second valve 8 to reduce the operation speed of the outbound oil product.

[0056] ② When the density values displayed by the first densitometer 12 and the second densitometer 13 tend to be stable and are consistent with the density of the pipeline-transported diesel batch, and the density value displayed by the third densitometer 14 is consistent with the density of the pipeline-transported gasoline batch, close the second valve 8 through the control device 3, and the subsequent inbound oil product flows into the storage tank 4.

[0057] ③ After the second valve 8 is completely closed, confirm the density values of the second densitometer 13 and the third densitometer 14 again. If there is no change, the mixed oil stops being transported in the front-gas-back-diesel stop-transport pipe 11. If the density value displayed by the third densitometer 14 becomes larger, then part of the mixed oil crosses the outlet of the mixed-oil stop-transport area 2. In this case, it is necessary to open the first valve 7 and the second valve 8 through the control device 3 to perform a reverse transportation operation. When the density value displayed by the third densitometer 14 returns to the density of the pipeline-transported gasoline batch and the density value displayed by the second densitometer 13 is the density of the pipeline-transported diesel batch, close the second valve 8 through the control device 3. If the density value displayed by the second densitometer 13 becomes smaller, then part of the mixed oil flows back to the position where the second densitometer 13 is located. In this case, it is necessary to open the second valve 8 through the control device 3 and continue to transport the oil product in the direction of the outbound pipeline until the density value displayed by the second densitometer 13 returns to the density of the pipeline-transported diesel batch and the density value displayed by the third densitometer 14 is the density of the pipeline-transported gasoline batch, and then close the second valve 8 through the control device 3.

[0058] In some embodiments, to facilitate the rapid stratification of gasoline and diesel and ensure that the mixed-oil stop-transport area 2 has sufficient capacity, the capacities of the front-diesel-back-gas stop-transport pipe 9 and the front-gas-back-diesel stop-transport pipe 11 are 5 to 10 times the amount of mixed oil. After the pipeline stops being transported, the mixed oil in the mixed-oil stop-transport area 3 stops flowing, and the gasoline and diesel in the mixed oil move according to their own densities and the elevation of the stop-transport section. The gasoline moves to the gasoline section, and the diesel moves to the diesel section, thereby reducing the amount of mixed oil. When the transportation starts again, the mixed oil is transported to the downstream of the pipeline along with the pipeline-transported oil product.

[0059] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0060] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for controlling the stopping position of mixed oil in a refined oil pipeline, characterized in that: Based on a device for controlling the stopping position of mixed oil in a refined oil pipeline, the device for controlling the stopping position of mixed oil in a refined oil pipeline includes: an oil delivery station yard (1) and a mixed oil stopping area (2); The oil delivery station yard (1) includes an oil storage tank (4), the oil storage tank (4) communicates with a refined oil pipeline (6) through a connecting pipe (5), a first valve (7) is arranged on the connecting pipe (5), and a second valve (8) is installed on the refined oil pipeline (6) downstream of the connection between the connecting pipe (5) and the refined oil pipeline (6); The mixed oil stopping area (2) includes a front-diesel-back-gasoline stopping pipe (9), an intermediate pipe (10), and a front-gasoline-back-diesel stopping pipe (11) connected to the refined oil pipeline (6) in sequence, and the front-diesel-back-gasoline stopping pipe (9) and the front-gasoline-back-diesel stopping pipe (11) are inclined, a first densitometer (12) is installed upstream of the front-diesel-back-gasoline stopping pipe (9), a second densitometer (13) is installed on the intermediate pipe (10), and a third densitometer (14) is installed downstream of the front-gasoline-back-diesel stopping pipe (11); It further includes a control device (3), and the control device (3) is electrically connected to the first valve (7), the second valve (8), the first densitometer (12), the second densitometer (13), and the third densitometer (14); The included angles between the front-diesel-back-gasoline stopping pipe (9) and the front-gasoline-back-diesel stopping pipe (11) and the horizontal plane are both greater than 15°; The method for controlling the stopping position of mixed oil in a refined oil pipeline includes the following steps: S1. According to the stopping plan of the refined oil pipeline, estimate the stopping position and the amount of mixed oil; S2. When the forward-moving oil product of the mixed oil is diesel and the backward-moving oil product is gasoline, when the value of the first densitometer (12) starts to decrease, open the first valve (7) and adjust the second valve (8) smaller; When the value of the first densitometer (12) is consistent with the density of the gasoline batch in pipeline transportation, and the values of the second densitometer (13) and the third densitometer (14) are both consistent with the diesel batch in pipeline transportation, close the second valve (8); S3. When the forward-moving oil product of the mixed oil is gasoline and the backward-moving oil product is diesel, when the value of the second densitometer (13) starts to increase, open the first valve (7) and adjust the second valve (8) smaller; When the values of the first densitometer (12) and the second densitometer (13) are both consistent with the diesel batch in pipeline transportation, and the third densitometer (14) is consistent with the density of the gasoline batch, close the second valve (8).

2. According to the method for controlling the stopping position of mixed oil in a refined oil pipeline described in claim 1, characterized in that: In step S2, after the second valve (8) is completely closed, confirm the values of the first densitometer (12) and the second densitometer (13) again. If the value of the second densitometer (13) becomes smaller, open the first valve (7) and the second valve (8) for reverse transportation until the values of the second densitometer (13) and the third densitometer (14) are both consistent with the diesel batch in pipeline transportation, then close the first valve (7) and the second valve (8); When the value of the first densitometer (12) increases, open the second valve (8) until the first densitometer (12) is consistent with the gasoline batch in the pipeline, and then close the second valve (8).

3. The method for controlling the stopping position of mixed oil in a refined oil pipeline according to claim 1, characterized in that: In step S3, after the second valve (8) is completely closed, confirm the values of the second densitometer (13) and the third densitometer (14) again. When the value of the third densitometer (14) increases, open the first valve (7) and the second valve (8) for reverse transportation until the value of the third densitometer (14) is consistent with the gasoline batch in the pipeline, and then close the first valve (7) and the second valve (8); When the value of the second densitometer (13) decreases, open the second valve (8) until the second densitometer (13) is consistent with the diesel batch in the pipeline, and then close the second valve (8).

4. The method for controlling the stopping position of mixed oil in a refined oil pipeline according to claim 1, characterized in that: The capacities of the front-diesel and rear-gasoline stop pipeline (9) and the front-gasoline and rear-diesel stop pipeline (11) are 5 to 10 times the amount of mixed oil.

Images