Gas-liquid two-phase flow sensor based on flow pattern

Abstract

The invention discloses a flow pattern-based gas-liquid two-phase flow sensor, which belongs to the technical field of fluid flow detection, and comprises a flow sensor, the two-phase fluid forms a first kind of'single-phase flow-like flow form ', a second kind of'axial symmetry flow form' and a third kind of'non-axial symmetry flow form 'in the channel. And a conical throttling element is installed for the second-type axial symmetric flow flowing form. For a third type of non-axisymmetric flow flowing form, a lower throttling element is fixedly arranged at the lower part in a fluid channel of the flow sensor when liquid is more and gas is less; and when the liquid is less and the gas is more, the upper throttling element is mounted. According to the flow sensor, convection type damage can be reduced, the flow sensor can effectively adapt to detection of three kinds of different gas-liquid two-phase flows, and meanwhile the measurement effect of the flow sensor is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fluid flow detection devices, and more specifically, to a gas-liquid two-phase flow sensor based on flow morphology. Background Art

[0002] As a kind of multiphase flow, gas-liquid two-phase flow is widely used in natural gas, petroleum, chemical industry, nuclear energy, aerospace and other fields. Unlike single-phase flow, gas-liquid two-phase flow contains both gas and liquid. When they coexist and flow at the same time, due to the large difference in the medium characteristics of the two-phase fluid, the physical parameters such as friction coefficient, fluid density and viscosity are different, and the two-phase fluids interact and influence each other, making the two-phase flow show quite complex characteristics compared with the single-phase flow. Many criteria relationships and analysis methods in single-phase flow cannot be directly applied to the study of gas-liquid two-phase. At the same time, under the influence of many working conditions such as gravity, temperature, pressure and phase flow, it is very difficult to detect the flow parameters of gas-liquid two-phase flow. In gas-liquid two-phase flow, different flow rates, pressures, pipeline layout conditions and pipeline geometry will cause different shapes of the phase interface and form different flow patterns. The gas-liquid two-phase flow patterns in horizontal circular pipes include bubbly flow, slug flow, plug flow, stratified flow, annular flow, mist flow, etc.

[0003] The distribution pattern of gas-liquid two-phase flow in the pipeline is obviously different from that of single-phase fluid, and can be divided into three flow types: the first type, mist flow, is similar to single-phase fluid, and the droplets are evenly distributed in the pipe cross section in an axisymmetric manner, which is called quasi-single-phase flow; the second type, bubbly flow and annular mist flow, the liquid phase is unevenly distributed in the pipe cross section, but is basically in an axisymmetric state, which is called axisymmetric flow; the third type, plug flow, stratified flow, stratified wavy flow, and elastic flow, the distribution of the liquid phase on the cross section is neither uniform nor axisymmetric, which is called non-axisymmetric flow.

[0004] At present, the measurement of gas-liquid two-phase flow does not take into account the factor of flow pattern distribution. Single-phase flow flow measurement sensors are directly used for all flow patterns. Single-phase flow flow sensors are suitable for measuring the flow pattern of the first type of single-phase flow. For measuring the second type of axisymmetric flow pattern of gas-liquid two-phase flow, it can be measured, but the effect is general, and for measuring the third type of non-axisymmetric flow pattern distribution, the measurement effect is very poor.

[0005] Therefore, in view of this, the existing structure is studied and improved, and a gas-liquid two-phase flow sensor based on flow morphology is provided, in order to achieve a more practical purpose. Summary of the invention

[0006] 1. Technical issues to be solved

[0007] In view of the problems existing in the prior art, the purpose of the present invention is to provide a gas-liquid two-phase flow sensor based on flow morphology, which can reduce the destruction of convection pattern and make the flow sensor effectively adapt to the detection of three different types of gas-liquid two-phase flows. At the same time, it effectively improves the measurement effect of the flow sensor.

[0008] 2. Technical solution

[0009] To solve the above problems, the present invention adopts the following technical solutions.

[0010] A gas-liquid two-phase flow sensor based on flow patterns includes a flow sensor, in which a first type of single-phase flow pattern, a second type of axisymmetric flow pattern and a third type of non-axisymmetric flow pattern are formed in the fluid channel of the flow sensor, and is characterized in that: the first type of single-phase flow pattern is installed with a orifice plate, the second type of axisymmetric flow pattern flows through a conical throttling member, and the third type of non-axisymmetric flow pattern is installed with an upper throttling member when there is less liquid and more gas, and the fluid flows through the lower part of the upper throttling member, and when there is more liquid and less gas, a lower throttling member is fixedly arranged at the lower part of the fluid channel of the flow sensor, and the fluid flows through the upper part of the lower throttling member.

[0011] Furthermore, the conical throttling member includes a central flow guide tube, a bracket is fixedly provided on the outer side of the central flow guide tube, the other end of the bracket is fixed to the inside of the flow sensor, and a guide member is fixedly provided on the inside of the central flow guide tube.

[0012] Furthermore, the central flow guide tube is provided with three subdivided flow openings, and the guide member is connected to the subdivided flow opening located in the middle position.

[0013] Furthermore, the guide member includes a central rod and a cone.

[0014] Furthermore, the upper throttling member comprises a straight flow guide tube, a flow guide plate is fixedly installed inside the straight flow guide tube, and the flow guide plate is vertically arranged to the inner wall of the straight flow guide tube.

[0015] Furthermore, the third type of non-axisymmetric flow pattern forms a two-phase flow of a low-level gas phase and a low-level liquid phase after passing through the upper throttling member.

[0016] Furthermore, the upper throttle member and the lower throttle member have the same structure and are symmetrically arranged in an upper and lower direction.

[0017] Furthermore, the third type of non-axisymmetric flow pattern forms a two-phase flow of a high-level gas phase and a high-level liquid phase after passing through the lower throttling member.

[0018] 3. Beneficial effects

[0019] Compared with the prior art, the advantages of the present invention are:

[0020] ①1① In this scheme, when using a flow sensor to detect gas-liquid two-phase flow under flow patterns, different throttling parts are selected and installed according to the distribution positions of three different types of gas-liquid two-phase flows formed inside the flow sensor, and the structure of the flow sensor is changed to guide the gas-liquid two-phase flow, and the interference and change to the original flow state are reduced as much as possible, so that the structure of the flow sensor adapts to the flow state, wherein the flow sensor can effectively detect the first type of gas-liquid two-phase flow of the single-phase flow pattern, and the throttling parts such as orifice plates are used to make the flow sensor adapt to the second type of gas-liquid two-phase flow of the axisymmetric flow pattern, and the conical throttling parts are used to make the flow sensor adapt to the third type of gas-liquid two-phase flow of the non-axisymmetric flow pattern, and the upper throttling parts or the lower throttling parts are used. In this way, while reducing the damage to the convection pattern, the flow sensor can be effectively adapted to the detection of three different types of gas-liquid two-phase flows, and at the same time, the measurement effect of the flow sensor is effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the flow sensor in the present invention;

[0022] Figure 2 It is a schematic diagram of the classification of the three types of flow patterns in the present invention;

[0023] Figure 3 It is a structural schematic diagram of the conical throttling member in the present invention;

[0024] Figure 4 For the present invention Figure 3 The structural diagram of the enlarged part A in the middle;

[0025] Figure 5 It is a structural schematic diagram of the upper throttling member in the present invention;

[0026] Figure 6 It is a schematic structural diagram of the lower throttling member in the present invention.

[0027] Description of the numbers in the figure:

[0028] 1. Flow sensor;

[0029] 2. The first type of single-phase flow pattern;

[0030] 3. The second type of axisymmetric flow pattern;

[0031] 4. The third type of non-axisymmetric flow pattern;

[0032] 5. Conical throttling piece;

[0033] 501, center flow guide pipe; 5011, subdivided flow outlet;

[0034] 502, bracket;

[0035] 503, guide piece; 5031, center rod; 5032, cone;

[0036] 6. upper throttle member; 601. straight flow guide tube; 602. guide plate;

[0037] 7. Lower throttle. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0039] Embodiment 1:

[0040] See also Figure 1 - Figure 6 A gas-liquid two-phase flow sensor based on flow morphology includes a flow sensor 1. A first type of quasi-single-phase flow morphology 2, a second type of axisymmetric flow morphology 3, and a third type of non-axisymmetric flow morphology 4 are formed in the fluid channel of the flow sensor 1. The first type of quasi-single-phase flow morphology 2 is a mist flow, which is similar to a single-phase fluid, and the droplets are axisymmetrically evenly distributed in the pipe cross section, which is called a quasi-single-phase flow.

[0041] The second type of axisymmetric flow pattern 3 is a bubbly flow or annular mist flow, in which the liquid phase is unevenly distributed in the pipe cross section, but is basically in an axisymmetric state, which is called axisymmetric flow;

[0042] The third type of non-axisymmetric flow pattern 4 is a plug flow, stratified flow, stratified wavy flow or slug flow, in which the distribution of the liquid phase on the cross section is neither uniform nor axisymmetric, which is called non-axisymmetric flow;

[0043] A conical throttling piece 5 is fixedly arranged in the middle of the fluid channel of the flow sensor 1. The second type of axisymmetric flow pattern 3 flows through the conical throttling piece 5. The conical throttling piece 5 can guide the fluid of the second type of axisymmetric flow pattern 3 with central throttling, reduce the damage to the flow pattern, and improve the measurement effect.

[0044] An upper throttling piece 6 is fixedly provided at the upper part of the fluid channel of the flow sensor 1 , and the third type of non-axisymmetric flow pattern 4 flows through the upper throttling piece 6 , which can guide the fluid in the lower part of the fluid channel of the third type of non-axisymmetric flow pattern 4 .

[0045] A lower throttling member 7 is fixedly provided at the lower part of the fluid channel of the flow sensor 1 , and the third type of non-axisymmetric flow pattern 4 flows through the lower throttling member 7 , which can guide the fluid in the upper part of the fluid channel of the third type of non-axisymmetric flow pattern 4 .

[0046] See also Figure 3 and Figure 4 Specifically, the conical throttling element 5 includes a central flow guide tube 501, a bracket 502 is fixedly provided on the outer side of the central flow guide tube 501, the other end of the bracket 502 is fixed to the inside of the flow sensor 1, and a guide member 503 is fixedly provided on the inside of the central flow guide tube 501.

[0047] The fluid of the second type axisymmetric flow pattern 3 passes through the central flow guide tube 501 and is then guided by the guide member 503, so that the structure of the flow sensor 1 adapts to the flow state, and placing the entire throttling member at a position with a high content of the second type axisymmetric flow pattern 3 can effectively improve the measurement effect.

[0048] Specifically, three subdivided flow openings 5011 are provided on the central flow guide pipe 501 , and the guide member 503 is connected to the subdivided flow opening 5011 located in the middle.

[0049] The three subdivided flow openings 5011 are marked as p1, p2 and p3 respectively, wherein the differential pressure between p1 and p2 is Δp1, and the differential pressure between p2 and p3 is Δp2, so that the drainage effect of the guide member 503 can be ensured.

[0050] Specifically, the guide member 503 includes a central rod 5031 and a cone 5032 .

[0051] The cone 5032 can effectively guide the fluid, thereby effectively improving the measurement effect.

[0052] Embodiment 2:

[0053] Based on the above embodiment 1, further description is given.

[0054] See also Figure 5 and Figure 6 Specifically, the upper throttling member 6 includes a straight flow guide tube 601 , and a guide plate 602 is fixedly installed inside the straight flow guide tube 601 , and the guide plate 602 is vertically arranged to the inner wall of the straight flow guide tube 601 .

[0055] The guide plate 602 is arranged inside the straight guide tube 601. The guide plate 602 can be used to guide the gas phase and liquid phase flowing through the upper throttling member 6, and a swirling flow is formed on the other side of the guide plate 602. Placing the upper throttling member 6 at a position with a high gas phase content in the third type of non-axisymmetric flow pattern 4 can effectively improve the measurement effect.

[0056] See also Figure 5 Specifically, the third type of non-axisymmetric flow pattern 4 forms a low-level gas phase and a low-level liquid phase after passing through the upper throttling member 6.

[0057] The guide plate 602 can effectively limit the flow of the gas phase, so that the structure of the flow sensor 1 adapts to the flow state.

[0058] See also Figure 5 and Figure 6 Specifically, the upper throttle member 6 and the lower throttle member 7 have the same structure, and the two are symmetrically arranged in an upper and lower direction.

[0059] See also Figure 6 Specifically, after the third type of non-axisymmetric flow pattern 4 passes through the lower throttling member 7, a high-level gas phase and a high-level liquid phase are formed.

[0060] The lower throttle member 7 is used to dredge the lower part of the fluid channel of the flow sensor 1 , and its function is similar to that of the upper throttle member 6 .

[0061] Embodiment 3:

[0062] Based on the above-mentioned Embodiment 1 and Embodiment 2, further description is given.

[0063] The experimental test data of the upper throttling gas-liquid two-phase flow sensor are as follows:

[0064]

[0065] Among them, the upper throttling gas-liquid two-phase flow sensor is mainly used to measure low-liquid stratified flow, wavy stratified flow, and elastic flow, and is used for two-phase flow measurement at the wellhead of gas wells in oil and gas fields.

[0066] The experimental test data of the lower throttling gas-liquid two-phase flow sensor are as follows:

[0067]

[0068] Among them, the down-throttling gas-liquid two-phase flow sensor is mainly used to measure high-liquid stratified flow, wavy stratified flow, elastic flow, bubbly flow, and plug flow, and is used for two-phase flow measurement at the wellhead of high-liquid oil wells in oil and gas fields.

[0069] Working principle:

[0070] When using the flow sensor 1 to detect the gas-liquid two-phase flow under the flow pattern, according to the three different types of gas-liquid two-phase flow patterns formed inside the flow sensor 1, different throttling parts are selected to install, and the structure of the flow sensor 1 is changed to guide the gas-liquid two-phase flow, and the interference and change to the original flow state are reduced as much as possible, so that the structure of the changed flow sensor 1 can adapt to the flow state.

[0071] Among them, the flow sensor 1 can effectively detect the gas-liquid two-phase flow of the first type of single-phase flow form 2.

[0072] The conical throttling piece 5 is installed in the middle of the fluid channel of the flow sensor 1. By using the conical throttling piece 5, the flow sensor 1 is adapted to the gas-liquid two-phase flow of the second type axisymmetric flow pattern 3.

[0073] The upper throttle member 6 is installed in the upper part of the fluid channel of the flow sensor 1, and the lower throttle member 7 is installed in the lower part of the fluid channel of the flow sensor 1. The upper throttle member 6 or the lower throttle member 7 is used to make the flow sensor 1 adapt to the gas-liquid two-phase flow of the third type of non-axisymmetric flow pattern 4. In this way, while reducing the destruction of the convection pattern, the flow sensor 1 can effectively adapt to the detection of three different types of gas-liquid two-phase flows. At the same time, the measurement effect of the flow sensor 1 is effectively improved.

[0074] The above is only a preferred specific implementation of the present invention; however, the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solution and its improved conception within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A gas-liquid two-phase flow sensor based on flow patterns, comprising a flow sensor (1), wherein a first type of quasi-single-phase flow pattern (2), a second type of axisymmetric flow pattern (3) and a third type of non-axisymmetric flow pattern (4) are formed in a fluid channel of the flow sensor (1), characterized in that: The first type of single-phase flow pattern (2) is equipped with an orifice plate, the second type of axisymmetric flow pattern (3) flows through a conical throttling member (5), and the third type of non-axisymmetric flow pattern (4) is equipped with an upper throttling member (6) when there is less liquid and more gas, and the fluid flows through the lower part of the upper throttling member (6), and when there is more liquid and less gas, a lower throttling member (7) is fixedly arranged at the lower part of the fluid channel of the flow sensor (1), and the fluid flows through the upper part of the lower throttling member (7).

2. The gas-liquid two-phase flow sensor based on flow morphology according to claim 1 is characterized in that: The conical throttling member (5) comprises a central flow guide tube (501), a bracket (502) is fixedly arranged on the outer side of the central flow guide tube (501), the other end of the bracket (502) is fixed to the inside of the flow sensor (1), and a guide member (503) is fixedly arranged on the inside of the central flow guide tube (501).

3. The gas-liquid two-phase flow sensor based on flow morphology according to claim 2 is characterized in that: The central flow guide tube (501) is provided with three subdivided flow openings (5011), and the guide member (503) is connected to the subdivided flow opening (5011) located in the middle.

4. The gas-liquid two-phase flow sensor based on flow morphology according to claim 2 is characterized in that: The flow guide (503) comprises a central rod (5031) and a cone (5032).

5. The gas-liquid two-phase flow sensor based on flow morphology according to claim 1, characterized in that: The upper throttling member (6) comprises a straight flow guide tube (601), a flow guide plate (602) is fixedly installed inside the straight flow guide tube (601), and the flow guide plate (602) is arranged vertically to the inner wall of the straight flow guide tube (601).

6. The gas-liquid two-phase flow sensor based on flow morphology according to claim 1, characterized in that: After passing through the upper throttling element (6), the third type of non-axisymmetric flow pattern (4) forms a fluid flow of a low-level gas phase and a low-level liquid phase.

7. The gas-liquid two-phase flow sensor based on flow morphology according to claim 1, characterized in that: The upper throttle member (6) and the lower throttle member (7) have the same structure and are symmetrically arranged in an upper and lower direction.

8. The gas-liquid two-phase flow sensor based on flow morphology according to claim 1, characterized in that: After passing through the lower throttling element (7), the third type of non-axisymmetric flow pattern (4) forms a fluid flow of a high-level gas phase and a high-level liquid phase.

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