A gas-liquid two-phase non-equiproportion sampling device

Abstract

A gas-liquid two-phase non-equiproportion sampling device mainly includes a shunt pipe, a cyclone, a main fluid and a shunt fluid sampling pipe, a sampling chamber, etc. A liquid groove is arranged on the shunt pipe wall, and the gas-phase shunt pipe and the liquid-phase shunt holes are arranged alternately in the circumferential position of the liquid groove. A liquid-phase sampling pipe is provided at the liquid-phase shunt hole of the sampling fluid. By changing the number of gas-phase and liquid-phase shunt pipes, the flow rates of the gas-phase and liquid-phase sampling fluids entering the sampling chamber can be changed, and thus the desired gas-liquid shunt ratio can be obtained. Compared with the prior art, the present invention is small in volume and compact in structure, and is not affected by parameters such as the inlet gas-liquid flow velocity and flow pattern.

Description

Technical Field

[0001] The present invention belongs to the field of fluid metering, and particularly relates to a gas-liquid two-phase non-equiproportion sampling device for multi-phase flow sampling and metering. Background Art

[0002] In the petroleum industry, the oil well produced fluids are usually mixtures of gas, liquid, and sediment. After simple separation, the obtained gas-liquid two-phase flow usually needs to be transported through pipelines to downstream oil and gas treatment stations. To ensure the effectiveness of energy utilization, there are certain requirements for the metering accuracy of the transported gas-liquid two-phase flow.

[0003] Currently, there are various sampling methods for the shunt and phase separation method, such as tee-tube type, sampling tube type, rotary drum type, rotary wheel type, cyclone type, etc. Except for the tee-tube type distributor, other samplers are uniform sampling without changing the gas-liquid composition of the sampled fluid. For two-phase fluids with a large difference in gas-liquid content, since the content of one of the fluids is relatively low, its content in the sampled fluid will be even lower after sampling. At this time, still using uniform sampling will seriously affect the accuracy of subsequent flow measurement. Although the tee-tube type distributor can achieve gas-liquid separation, only the gas phase enters the upper branch pipe, and it is impossible to simultaneously measure the gas-liquid two-phase flow rates.

[0004] To overcome the defects of the prior art, the present invention proposes a gas-liquid two-phase non-equiproportion sampling device. The gas and liquid phases can be sampled separately through the gas-phase shunt pipe of the sampled fluid and the liquid-phase sampling pipe. By changing the number of the gas-phase shunt pipe or the liquid-phase sampling pipe of the sampled fluid, the gas-liquid phase shunt ratio can be changed. For the fluid with a relatively low phase fraction in the two-phase flow, its shunt ratio can be increased, thereby improving the metering accuracy of the gas-liquid two-phase flow. Summary of the Invention

[0005] The present invention relates to a gas-liquid two-phase non-equiproportion sampling device, which mainly includes a shunt pipe, a cyclone, a main flow chamber, a sampling chamber, a liquid tank, a baffle, a main fluid outlet pipe, a sampled fluid gas-phase outlet pipe, and a sampled fluid liquid-phase outlet pipe. The cyclone is arranged near the inlet of the shunt pipe, and the swirl vanes of the cyclone are closely attached to the inner wall surface of the shunt pipe. The downstream outlet of the shunt pipe is closed by the baffle. The liquid tank is an annular channel and is located between the cyclone and the baffle on the shunt pipe. The main flow chamber is arranged on the outer edge of the shunt pipe, covering the liquid tank and the inlet of the main fluid outlet pipe. The sampling chamber is arranged on the outer edge of the main flow chamber, and the main flow chamber and the sampling chamber are coaxial. The main fluid outlet pipe is communicated with the main flow chamber. The sampled fluid gas-phase outlet pipe is arranged at the top of the sampling chamber, and the sampled fluid liquid-phase outlet pipe is arranged at the bottom of the sampling chamber.

[0006] A number of liquid-phase shunt holes are arranged at the bottom of the liquid tank. The liquid-phase shunt holes include the main-stream liquid-phase shunt holes and the sampling-fluid liquid-phase shunt holes. Among them, the sampling-fluid liquid-phase shunt holes are connected to the sampling chamber through a liquid-phase sampling pipe, and the main-stream liquid-phase shunt holes are directly connected to the main-stream chamber. The gas-phase shunt pipe consists of the main-stream gas-phase shunt pipe and the sampling-fluid gas-phase shunt pipe. The gas-phase shunt pipe extends deep into the shunt pipe. Among them, the main-stream gas-phase shunt pipe penetrates through the liquid tank and is arranged at the liquid tank for connecting the main-stream chamber, and the sampling-fluid gas-phase shunt pipe penetrates through the main-stream chamber and is arranged on the main-stream chamber for connecting the sampling chamber. Gas-phase shunt holes are arranged at the centers of the inlets of both the main-stream gas-phase shunt pipe and the sampling-fluid gas-phase shunt pipe.

[0007] The structures of the gas-phase shunt holes on the main-stream gas-phase shunt pipe and the sampling-fluid gas-phase shunt pipe are exactly the same, and the structures of the main-stream liquid-phase shunt holes and the sampling-fluid liquid-phase shunt holes are exactly the same, both being circular-hole structures. However, the structures of the gas-phase shunt holes and the liquid-phase shunt holes are not the same, and the numbers of both the gas-phase shunt holes and the liquid-phase shunt holes are not less than 2.

[0008] The inlets of the several gas-phase shunt pipes are evenly arranged along the circumferential direction of the shunt pipe. There is only one gas-sampling hole on each gas-phase shunt pipe. One liquid-phase sampling pipe is only connected to one sampling-fluid liquid-phase shunt hole. The gas-phase shunt pipes and the liquid-phase shunt holes are arranged staggeredly on the liquid tank and are all located in a plane perpendicular to the axis of the liquid tank.

[0009] Compared with the prior art, the present invention has the following advantages:

[0010] (1) Under the action of the cyclone, the wave flow, stratified flow and uneven annular flow can be integrated into an annular flow with a uniform liquid film thickness, effectively eliminating the influence of the two-phase flow pattern fluctuation on the measurement.

[0011] (2) By changing the numbers of the sampling-fluid gas-phase shunt pipe and the liquid-phase sampling pipe, the gas-liquid two-phase shunt ratio can be adjusted.

[0012] (3) The existence of the liquid tank can make the liquid phase in the annular flow rectified by the cyclone concentrate in the liquid tank, reducing gas entrainment.

[0013] (4) Gas-sampling holes are arranged at the inlets of the gas-phase shunt pipes, making the resistance characteristics concentrated at the orifice, eliminating the different flow characteristics caused by the different lengths between the main-stream gas-phase shunt pipe and the sampling-fluid gas-phase shunt pipe.

[0014] (5) Gas-phase outlet pipes and liquid-phase outlet pipes are respectively arranged at the top and bottom of the sampling chamber. The sampling chamber is not only used to collect the sampling fluid, but also can be used as a separator to further improve the measurement accuracy of the gas-liquid phases of the sampling fluid.

[0015] (6) There are no moving parts, the structure is simple, and it has the characteristics of low operating cost, convenient operation and high measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the composition of the present invention;

[0017] Figure 2 It is a schematic diagram of the first example of the present invention;

[0018] Figure 3 It is an enlarged view of the gas sampling tube of the present invention;

[0019] Figure 4 It is a working principle diagram of the present invention;

[0020] Figure 5 It is a working principle diagram of the A-A section of the present invention;

[0021] Figure 6 It is a schematic diagram of the second example of the present invention;

[0022] Figure 7 It is a schematic diagram of the third example of the present invention.

[0023] 1 - shunt pipe; 2 - cyclone; 3 - main flow chamber; 4 - sampling chamber; 5 - liquid tank; 6 - baffle; 7 - main fluid outlet pipe; 8 - sampling fluid gas-phase outlet pipe; 9 - sampling fluid liquid-phase outlet pipe; 10 - main fluid liquid-phase shunt hole; 11 - sampling fluid liquid-phase shunt hole; 12 - liquid-phase sampling pipe; 13 - main fluid gas-phase shunt pipe; 14 - sampling fluid gas-phase shunt pipe; 15 - gas-phase shunt hole. DETAILED DESCRIPTION OF THE INVENTION

[0024] As Figure 1 shown, it mainly includes: a shunt pipe 1, a cyclone 2, a main flow chamber 3, a sampling chamber 4, a liquid tank 5, a baffle 6, a main fluid outlet pipe 7, a sampling fluid gas-phase outlet pipe 8 and a sampling fluid liquid-phase outlet pipe 9. The cyclone 2 is arranged near the inlet of the shunt pipe 1, and the swirl vanes of the cyclone 2 are closely attached to the inner wall surface of the shunt pipe 1. The downstream outlet of the shunt pipe 1 is closed by the baffle 6. The liquid tank 5 is an annular channel and is located between the cyclone 2 and the baffle 6 on the shunt pipe 1. The main flow chamber 3 is arranged on the outer edge of the shunt pipe 1, covering the liquid tank 5 and the inlet of the main fluid outlet pipe 7. The sampling chamber 4 is arranged on the outer edge of the main flow chamber 3, and the main flow chamber 3 and the sampling chamber 4 are coaxial. The main fluid outlet pipe 7 is communicated with the main flow chamber 3. The sampling fluid gas-phase outlet pipe 8 is arranged at the top of the sampling chamber 4, and the sampling fluid liquid-phase outlet pipe 9 is arranged at the bottom of the sampling chamber 4.

[0025] As Figure 2As shown in the figure, a number of liquid-phase shunt holes are arranged at the bottom of the liquid tank 5. The liquid-phase shunt holes include the main-stream liquid-phase shunt holes 10 and the sampling-fluid liquid-phase shunt holes 11. Among them, the sampling-fluid liquid-phase shunt holes 11 are connected to the sampling chamber 4 through the liquid-phase sampling pipe 12, and the main-stream liquid-phase shunt holes 10 are directly connected to the main-stream chamber 3. The gas-phase shunt pipe is composed of the main-stream gas-phase shunt pipe 13 and the sampling-fluid gas-phase shunt pipe 14. The gas-phase shunt pipe extends deep into the shunt pipe 1. Among them, the main-stream gas-phase shunt pipe 13 penetrates through the liquid tank 5 and is arranged at the liquid tank 5 for connecting the main-stream chamber 3. The sampling-fluid gas-phase shunt pipe 14 penetrates through the main-stream chamber 3 and is arranged on the main-stream chamber 3 for connecting the sampling chamber 4. Gas-phase shunt holes 15 are arranged at the centers of the inlets of the main-stream gas-phase shunt pipe 13 and the sampling-fluid gas-phase shunt pipe 14.

[0026] The structures of the gas-phase shunt holes 15 on the main-stream gas-phase shunt pipe 13 and the sampling-fluid gas-phase shunt pipe 14 are exactly the same, and the structures of the main-stream liquid-phase shunt holes 10 and the sampling-fluid liquid-phase shunt holes 11 are exactly the same, both being circular-hole structures. However, the structure of the gas-phase shunt holes 15 is not the same as that of the liquid-phase shunt holes. The numbers of the gas-phase shunt holes 15 and the liquid-phase shunt holes are both not less than 2.

[0027] As Figure 3 shown in the figure, the inlets of the several gas-phase shunt pipes are uniformly arranged along the circumferential direction of the shunt pipe 1. There is only one gas-phase sampling hole 15 on each gas-phase shunt pipe. One liquid-phase sampling pipe 12 is only connected to one sampling-fluid liquid-phase shunt hole 11. The gas-phase shunt pipes and the liquid-phase shunt holes are arranged staggeredly on the liquid tank 5 and are all located in a plane perpendicular to the axis of the liquid tank 5.

[0028] The working principle of the present invention is described as follows:

[0029] As Figure 4 shown in the figure, the swirling vanes of the cyclone 2 are closely attached to the inner wall surface of the shunt pipe 1. After the gas-liquid two-phase fluid enters the shunt pipe 1, it passes through the cyclone 2 and is forced to flow in the channel formed by the swirling vanes and the wall surface of the shunt pipe 1. Due to the action of the centrifugal force and the fact that the density of the liquid phase is much greater than that of the gas phase, the liquid phase is thrown to the outermost side to form a liquid film closely attached to the wall surface of the shunt pipe 1, while the gas phase flows in the center of the shunt pipe 1. At this time, the flow pattern is a uniform annular flow. For a horizontal pipe without a swirling device, under the action of gravity, the gas-liquid two-phase is significantly asymmetrically distributed in the pipe cross-section, with more liquid phase at the bottom and the gas phase mainly concentrated in the upper part of the pipe. After passing through the cyclone 2, flow patterns such as stratified flow, wavy flow, semi-annular flow, and asymmetric annular flow are all adjusted to a uniform annular flow pattern with the liquid film uniformly distributed along the pipe circumference.

[0030] Since the end of the shunt pipe 1 is closed by the baffle 6, the rectified annular flow can only be shunted through the gas-phase shunt holes 15 and the liquid-phase shunt holes. As Figure 5As shown, the liquid phase flows closely along the tube wall and then flows into the liquid tank 5. Since the aperture of the liquid phase shunt hole is relatively small, the resistance of the liquid phase when flowing through the orifice is relatively large. The presence of the liquid tank 5 can cause the liquid phase to converge to a certain depth, thereby preventing the gas phase from entering the liquid phase shunt hole. A part of the liquid phase directly enters the main flow chamber 3 through the main flow liquid phase shunt hole 10, and the rest is the sampling fluid, which enters the sampling chamber 4 through the liquid phase sampling tube 12 connected to the sampling fluid liquid phase shunt hole 11. Since the liquid phase shunt ratio only depends on the ratio of the number of sampling fluid liquid phase shunt holes 11 connected to the liquid phase sampling tube 12 to the total number of liquid phase shunt holes, the liquid phase shunt ratio can be changed by changing the number of liquid phase sampling tubes 12.

[0031] As Figure 5 shown, the gas phase flows at the central position of the shunt tube 1 and then flows into the main flow gas phase shunt tube 13 and the sampling fluid gas phase shunt tube 14 respectively through the gas phase shunt hole 15. Since the aperture of the gas phase shunt hole 15 is relatively small, the resistance characteristics can be concentrated at the orifice. The gas phase flowing into the downstream directly enters the main flow chamber 3 through the main flow gas phase shunt tube 13, and the gas used for sampling flows into the sampling chamber 4 through the sampling fluid gas phase shunt tube 14. Since the gas phase shunt ratio only depends on the ratio of the number of sampling fluid gas phase shunt tubes 14 to the total number of gas phase shunt tubes, the gas phase shunt ratio can be changed by changing the number of sampling fluid gas phase shunt tubes 14.

[0032] After the sampling fluid flowing out through the sampling fluid gas phase shunt tube 14 and the sampling fluid liquid phase shunt hole 11 is secondarily separated in the sampling chamber 4, the gas phase flows out through the sampling fluid gas phase outlet tube 8 at the top of the sampling chamber 4, and the liquid phase flows out through the sampling fluid liquid phase outlet tube 9 at the bottom of the sampling chamber 4. As Figure 4 shown, the main flow fluid flowing out through the main flow gas phase shunt tube 13 and the main flow liquid phase shunt hole 10 enters the main flow chamber 3 and then flows out through the main flow outlet tube 7.

[0033] The following is an example illustration for non-equal ratio shunting:

[0034] Example 1: Liquid phase shunt ratio 1 / 4, gas phase shunt ratio 1 / 2;

[0035] As Figure 2 shown, when the sampling device has 4 liquid phase shunt holes and 1 liquid phase sampling tube, the liquid phase shunt ratio can be guaranteed to be 1 / 4; when the sampling device has 4 gas phase shunt tubes, and 2 of them are sampling fluid gas phase shunt tubes, the gas phase shunt ratio can be guaranteed to be 1 / 2, which can be used to measure gas-liquid two-phase fluids with less gas phase content and more liquid phase content.

[0036] Example 2: Liquid phase shunt ratio 1 / 4, gas phase shunt ratio 1 / 4;

[0037] As Figure 6As shown in the figure, when the number of liquid-phase shunt holes and gas-phase shunt pipes of the sampling device are both 4, and the number of liquid-phase sampling pipes and sampling fluid gas-phase shunt pipes are both 1, the liquid-phase shunt ratio and gas-phase shunt ratio can be ensured to be both 1 / 4, which can be used for measuring gas-liquid two-phase fluids with uniform gas-liquid two-phase content.

[0038] Example 3: Liquid-phase shunt ratio 1 / 2, gas-phase shunt ratio 1 / 4;

[0039] As Figure 7 shown in the figure, when the sampling device has 4 liquid-phase shunt holes and 2 liquid-phase sampling pipes, the liquid-phase shunt ratio can be ensured to be 1 / 2; when the sampling device has 4 gas-phase shunt pipes, and 1 of them is the sampling fluid gas-phase shunt pipe, the gas-phase shunt ratio can be ensured to be 1 / 4, which can be used for measuring gas-liquid two-phase fluids with less liquid-phase content and more gas-phase content.

[0040] For the convenience of description of the present invention, the number of gas-liquid shunt holes and sampling pipes shown in the embodiments is small. In actual applications, more gas-liquid shunt holes and sampling pipes can be used to achieve more shunt ratio combinations. Therefore, the numbers of the sampling fluid gas-phase shunt pipe 14 and the liquid-phase sampling pipe 12 described in the present invention can be adjusted by themselves, so as to achieve different gas-phase and liquid-phase shunt ratios to meet the shunt ratio requirements of different working conditions.

[0041] The present invention adopts the design of separately sampling gas-liquid two phases, and changes the gas-liquid two-phase shunt ratio by changing the number of sampling fluid gas-phase shunt pipes and the number of liquid-phase sampling pipes. The gas-phase and liquid-phase shunt ratios both depend on the ratio of the number of shunt holes responsible for sampling each phase to the total number of shunt holes of each phase. The advantages of the present invention are that it can achieve equal-proportion sampling of gas and liquid, and can also achieve non-equal-proportion sampling. Users can select appropriate shunt ratios according to actual situations. Compared with the prior art, it has better applicability. In addition, the present invention has no moving parts, has a simple structure, is not affected by factors such as the gas-liquid flow pattern in the pipeline and the gas-liquid flow velocity, and has the characteristics of low operating cost, convenient operation and high measurement accuracy.

Claims

1. A gas-liquid two-phase non-equal-proportion sampling device, characterized in that, It mainly includes: a shunt pipe (1), a hydrocyclone (2), a main flow chamber (3), a sampling chamber (4), a liquid tank (5), a baffle (6), a main fluid outlet pipe (7), a sampling fluid gas-phase outlet pipe (8) and a sampling fluid liquid-phase outlet pipe (9). The hydrocyclone (2) is arranged near the inlet of the shunt pipe (1), and the swirl vanes of the hydrocyclone (2) are closely attached to the inner wall surface of the shunt pipe (1). The downstream outlet of the shunt pipe (1) is closed by the baffle (6). The liquid tank (5) is an annular channel and is located between the hydrocyclone (2) and the baffle (6) on the shunt pipe (1). The main flow chamber (3) is arranged on the outer edge of the shunt pipe (1) to cover the liquid tank (5) and the inlet of the main fluid outlet pipe (7). The sampling chamber (4) is arranged on the outer edge of the main flow chamber (3), and the main flow chamber (3) and the sampling chamber (4) are coaxial. The main fluid outlet pipe (7) is communicated with the main flow chamber (3). The sampling fluid gas-phase outlet pipe (8) is arranged at the top of the sampling chamber (4), and the sampling fluid liquid-phase outlet pipe (9) is arranged at the bottom of the sampling chamber (4); A number of liquid-phase shunt holes are arranged at the bottom of the liquid tank (5). The liquid-phase shunt holes include a main fluid liquid-phase shunt hole (10) and a sampling fluid liquid-phase shunt hole (11). Among them, the sampling fluid liquid-phase shunt hole (11) is connected to the sampling chamber (4) through a liquid-phase sampling pipe (12), and the main fluid liquid-phase shunt hole (10) is directly connected to the main flow chamber (3). The gas-phase shunt pipe is composed of a main fluid gas-phase shunt pipe (13) and a sampling fluid gas-phase shunt pipe (14). The gas-phase shunt pipe extends into the shunt pipe (1). Among them, the main fluid gas-phase shunt pipe (13) penetrates through the liquid tank (5) and is arranged at the liquid tank (5) for communicating with the main flow chamber (3). The sampling fluid gas-phase shunt pipe (14) penetrates through the main flow chamber (3) and is arranged on the main flow chamber (3) for communicating with the sampling chamber (4). Gas-phase shunt holes (15) are arranged at the centers of the inlets of the main fluid gas-phase shunt pipe (13) and the sampling fluid gas-phase shunt pipe (14).

2. The gas-liquid two-phase non-equiproportion sampling device according to claim 1, characterized in that: The structures of the gas-phase shunt holes (15) on the main fluid gas-phase shunt pipe (13) and the sampling fluid gas-phase shunt pipe (14) are completely the same, and the structures of the main fluid liquid-phase shunt hole (10) and the sampling fluid liquid-phase shunt hole (11) are completely the same, both being circular hole structures. However, the structure of the gas-phase shunt hole (15) is not the same as that of the liquid-phase shunt hole, and the numbers of the gas-phase shunt hole (15) and the liquid-phase shunt hole are not less than 2.

3. The gas-liquid two-phase non-equal proportion sampling device according to claim 1, characterized in that: The inlets of a number of the gas-phase shunt pipes are evenly arranged along the circumferential direction of the shunt pipe (1). There is only one gas-phase shunt hole (15) on each gas-phase shunt pipe. One liquid-phase sampling pipe (12) is only connected to one sampling fluid liquid-phase shunt hole (11). The gas-phase shunt pipes and the liquid-phase shunt holes are staggered on the liquid tank (5) and are all located in a plane perpendicular to the axis of the liquid tank (5).

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