Double differential pressure type moisture flow measuring device and measuring method

Abstract

The invention discloses a double differential pressure type moisture flow measuring device and method. The device comprises a measuring tube, and a pressure transmitter is installed on the upstream of the measuring tube; a porous pore plate and a V-shaped cone throttling element are installed in the middle of the measuring tube, the two sides of the porous pore plate are connected with a first three-valve set, and a first differential pressure transmitter is installed on the first three-valve set; the two sides of the V-cone throttling element are connected with a second three-valve set, and a second differential pressure transmitter is installed on the second three-valve set. A temperature transmitter is mounted at the downstream of the measuring pipe; the pressure transmitter, the first differential pressure transmitter, the second differential pressure transmitter and the temperature transmitter are respectively connected with the industrial computer. The measuring device disclosed by the invention has a wider metering range, can perform gas-liquid phase simultaneous metering on the moisture, is high in metering precision and low in maintenance cost, obtains the gas-liquid phase mass flow rate by solving a metering model, and is higher in calculation speed, high in model precision and high in adaptability to different working conditions.

Description

Technical Field

[0001] The invention relates to the field of flow measurement, and in particular to a dual differential pressure wet gas flow measurement device and a measurement method. Background Art

[0002] Wet gas is a special form of gas-liquid two-phase flow, which is widely present in many industrial fields. In the oil and gas extraction industry, as some oil and gas enter the final stage of recovery, the water content in the output increases significantly, and a small amount of liquid phase that is difficult to separate exists in the output. During the oil and gas transportation process, due to changes in pressure and temperature, the content of the liquid phase gradually increases with the transportation process, forming wet gas. The liquid phase is a medium or multiple media that exist in the wet gas, which exists in a free state. Especially in the process of oil and gas field exploitation, it is always produced together with liquid hydrocarbons, water vapor, etc. The accuracy of wet gas measurement is closely related to the understanding of the production capacity of oil and gas wells. It can be seen that the study of wet gas itself and its measurement method is part of the study of gas-liquid two-phase flow. It is very important and necessary to detect the real-time flow of gas-liquid two-phase flow and optimize the production process.

[0003] There are three main types of moisture measurement currently:

[0004] The first is a wet gas flow meter based on a gas flow meter that is only used for gas phase measurement. It only measures the gas phase. When the liquid content in the wet gas produced from the wellhead is small and the measurement accuracy requirement is not high, and the error caused by the liquid phase is acceptable, the gas flow meter is directly used for measurement, and the liquid phase flow is not measured. Therefore, it is not applicable when the liquid phase flow is large, real-time measurement of the liquid phase flow is required, or higher measurement accuracy is required.

[0005] The second is a wet gas flow meter based on a gas phase flow meter and a correction model that is only used for gas phase measurement. When the liquid phase flow rate does not change much over a period of time, the liquid phase flow rate or liquid phase content (known) is determined by other methods such as regular or irregular sampling and analysis, and the gas phase flow rate is obtained by model correction. This method is only applicable to situations where the liquid phase flow rate does not change much over a period of time. When the liquid phase flow rate changes greatly over time, this method will have a large error. It is necessary to obtain the liquid phase flow rate or liquid phase content by other methods regularly or irregularly according to the changes in the liquid phase flow rate, and input it into the model. The real-time performance of the liquid phase correction is difficult to guarantee, which also increases the extra workload.

[0006] The third is the wet gas flowmeter for gas-liquid two-phase measurement, which is usually composed of two or more gas phase flowmeters, or a combination of a differential pressure flowmeter and a phase content flowmeter (gamma, microwave). By measuring the content of each component in the wet gas, the two-phase flow correction model is used to correct the gas-liquid two-phase of the wet gas, and then the flow of each phase of the wet gas is measured. This method has high accuracy, but because gamma rays have certain radioactivity, strict radioactive protection is required, and its price is high. The most commonly used method now is to measure by combining two differential pressure flowmeters (standard orifice plates, venturi tubes, etc.). It has a simple structure, reliable measurement, low cost, and high accuracy, but the standard throttling parts (standard orifice plates, venturi tubes), etc., have a relatively narrow range. Under wellhead conditions, the produced fluid usually contains certain impurities, and the throttling parts are prone to blockage, affecting the measurement, and the ability to resist impurities is also weak. Therefore, a wet gas flowmeter suitable for the wellhead production environment and capable of real-time monitoring of flow changes is needed. Summary of the invention

[0007] In order to solve the above technical problems, the present invention provides a dual differential pressure wet gas flow measurement device and measurement method, which can monitor the wellhead produced fluid in real time with high measurement accuracy, and has the advantages of not easy to be blocked, self-rectified, and self-cleaned, which is convenient for large-scale production and has low production cost.

[0008] To achieve the above object, the technical solution of the present invention is as follows:

[0009] A dual differential pressure wet gas flow measurement device comprises a measuring tube, wherein a pressure transmitter is installed upstream of the measuring tube; a multi-hole plate and a V-cone throttling piece are installed in the middle of the measuring tube, a pressure hole 1 and a pressure hole 2 are provided on the measuring tubes on both sides of the multi-hole plate, the pressure hole 1 and the pressure hole 2 are connected to a three-valve group 1 through a pressure pipe 1 and a pressure pipe 2 respectively, and a differential pressure transmitter 1 is installed on the three-valve group 1; a pressure hole 3 is provided on the measuring tube at the front end of the V-cone throttling piece, and the pressure hole 1 and the pressure hole 2 are connected to a three-valve group 1 through a pressure pipe 1 and a pressure pipe 2 respectively. A pressure hole four is provided on the measuring tube above the V-cone throttling device, and the pressure hole three and the pressure hole four are connected to the three-valve group two through the pressure tube three and the pressure tube four respectively, and the differential pressure transmitter two is installed on the three-valve group two, and the pressure tube four enters the front end of the V-cone throttling device from the pressure hole four and extends into the center of the tail end; a temperature transmitter is installed downstream of the measuring tube; the pressure transmitter, the differential pressure transmitter one, the differential pressure transmitter two, and the temperature transmitter are respectively connected to the industrial computer.

[0010] In the above scheme, pressure taking valves are arranged on the pressure taking pipe 1, the pressure taking pipe 2, the pressure taking pipe 3 and the pressure taking pipe 4.

[0011] A dual differential pressure wet gas flow measurement method, using the dual differential pressure wet gas flow measurement device as described above, comprises the following steps:

[0012] Step 1, using a standard gas flowmeter and a standard liquid flowmeter to measure the mass flow rate of the gas phase and the mass flow rate of the liquid phase respectively, to obtain a standard value of the gas phase flow rate and a standard value of the liquid phase flow rate;

[0013] Step 2, the gas phase and liquid phase flowing through the standard gas flowmeter and the standard liquid flowmeter are mixed into wet gas and then passed into a horizontally placed dual differential pressure wet gas flow measurement device, and the pressure in the measuring tube, the multi-hole orifice plate differential pressure, the V-cone differential pressure and the temperature in the measuring tube are collected through the pressure transmitter, the differential pressure transmitter 1, the differential pressure transmitter 2 and the temperature transmitter;

[0014] Step 3, calculating the porous plate apparent mass flow rate, V-cone apparent mass flow rate and gas phase density through the collected data;

[0015] Step 4, substituting the calculated porous plate apparent mass flow rate, V-cone apparent mass flow rate, gas phase density and known parameters into the correction model, fitting them with the standard value of gas phase flow rate and the standard value of liquid phase flow rate, and calculating the constants in the correction model;

[0016] Step 5, substituting the calculated constants into the correction model to obtain a metering model of the dual differential pressure wet gas flow measurement device;

[0017] Step 6. During the actual measurement process, the dual differential pressure wet gas flow measurement device is placed horizontally and installed on the equipment production pipeline through a flange. The porous orifice plate differential pressure, V-cone differential pressure and the temperature in the measuring tube are collected to calculate the porous orifice plate apparent mass flow, V-cone apparent mass flow and gas phase density. The calculated porous orifice plate apparent mass flow, V-cone apparent mass flow and gas phase density are substituted into the metering model, and the actual gas phase mass flow and liquid phase mass flow of the equipment production pipeline are obtained by solving the Newton iteration method.

[0018] In the above scheme, the specific method of step 3 is as follows:

[0019] First, the gas phase density ρ is calculated by using the temperature T and pressure P in the pipeline output by the temperature transmitter and the pressure transmitter. g :

[0020]

[0021] Then, the apparent mass flow rate m of the porous plate is calculated by the differential pressure value output by differential pressure transmitter 1 and differential pressure transmitter 2. gApparentO and V-cone apparent mass flow rate m gApparentV :

[0022]

[0023]

[0024] Among them, Δp O , Δp V are the differential pressure values ​​output by differential pressure transmitter 1 and differential pressure transmitter 2, C is the outflow coefficient, β o , β V are the aperture ratios of the porous orifice plate and the V-cone throttling element, ε O , ε V are the expansion coefficients of the porous orifice plate and the V-cone throttling element, d o d V They are the converted diameters of the porous orifice plate and the V-cone throttling element respectively.

[0025] In the above scheme, in step 4, the correction model is as follows:

[0026]

[0027] Among them, Or o It is the false high value of the differential pressure transmitter when the humid air flows through. m g is the standard value of gas phase flow rate, m gApparentO is the apparent mass flow rate of the porous plate; X LM 、Dr、Fr g are several dimensionless parameters describing the characteristics of moisture, among which X LM is the pressure drop ratio between the gas phase and the liquid phase, that is m l is the standard value of liquid phase flow rate, ρg is the gas phase density, ρ l is the liquid phase density; Dr is the gas-liquid density ratio, that is Fr g It is used to characterize the relative magnitude of inertial force and gravity in fluid flow, that is, A, B, D, E, F, G, H are constants, Or V It is the false high value of differential pressure transmitter 2 when the humid air flows through. m gApparentV is the V-cone apparent mass flow rate.

[0028] Through the above technical solution, the present invention provides a dual differential pressure wet gas flow measurement device and a measurement method having the following characteristics:

[0029] Beneficial effects:

[0030] 1. The present invention proposes a dual differential pressure wet gas flow meter measuring device based on a porous orifice plate and a V-cone throttling element and a correction model based on the dual differential pressure wet gas flow meter measuring device. By installing the dual differential pressure wet gas flow meter on the equipment pipeline, the wet gas can be directly measured without separation, and the wellhead produced fluid can be monitored in real time.

[0031] 2. The present invention uses a porous orifice plate as an upstream throttling device. The porous orifice plate is suitable for measuring the flow of gas phase, steam and liquid phase. It has a wide range of applications and a simple structure that is easy to replicate. The performance of the orifice flowmeter is relatively stable. Even after long-term use, as long as it is properly maintained, it can maintain a good measurement effect. When the orifice flowmeter is used in conjunction with a differential pressure transmitter, a high-range ratio differential pressure flow measurement device can be formed, which makes it more flexible in dealing with a wide range of flow changes. Compared with the standard orifice plate, it has the advantages of not easy to clog, white rectification, white cleaning, etc., and it is very convenient for large-scale production with low production cost.

[0032] 3. The present invention uses a V-cone throttling piece as a downstream throttling piece. The structure of the V-cone throttling piece is relatively simple, mainly composed of a V-cone body and a straight pipe section. Compared with other types of flow meters, the V-cone throttling piece has a smaller pressure loss, and has a higher measurement accuracy, especially at a lower Reynolds number. It can also maintain good linearity. The V-cone throttling piece has a wider range ratio, generally above 10:1, and can even reach 20:1. This makes it more flexible when dealing with a wide range of flow changes. The V-cone throttling piece can be applied to the measurement of various gas phases, liquid phases and steam, including dirty flow, pulsating flow and high moisture content gas phase, and because of its advantages of white cleaning and white rectification, it has been widely used in the field of flow measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0034] Figure 1 A schematic diagram of a dual differential pressure wet gas flow measurement device disclosed in an embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of the installation of a multi-hole plate;

[0036] Figure 3 This is a schematic diagram of the installation of the V-cone throttling piece;

[0037] Figure 4 is the relative error plot of the gas phase test set;

[0038] Figure 5 This is the relative error plot of the liquid phase test set.

[0039] In the figure, 1. measuring tube; 2. multi-hole orifice plate; 3. V-cone throttling piece; 4. pressure transmitter; 5. differential pressure transmitter 1; 6. differential pressure transmitter 2; 7. temperature transmitter; 8. three-valve group 1; 9. three-valve group 2; 10. pressure valve; 11. industrial computer; 12. flange; 13. screw mounting hole; 14. pressure hole 1; 15. pressure hole 2; 16. pressure hole 3; 17. pressure hole 4; 18. pressure tube 1; 19. pressure tube 2; 20. pressure tube 3; 21. pressure tube 4. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0041] The present invention provides a dual differential pressure wet gas flow measurement device, such as Figure 1 As shown, it includes a measuring tube 1, and a pressure transmitter 4 is installed upstream of the measuring tube 1 to measure the pressure in the tube 1 in real time. A temperature transmitter 7 is installed downstream of the measuring tube 1 to measure the temperature in the tube 1 in real time.

[0042] A porous plate 2 and a V-cone throttling piece 3 are installed in the middle of the measuring tube 1. In this embodiment, the porous plate 2 is installed upstream of the measuring tube 1, and the V-cone throttling piece 3 is installed downstream of the measuring tube 1. The installation position can also be adjusted forward and backward.

[0043] A pressure hole 14 and a pressure hole 2 15 are provided on the measuring tube 1 on both sides of the porous orifice plate 2. The pressure hole 14 and the pressure hole 2 15 are connected to a three-valve group 8 through a pressure pipe 18 and a pressure pipe 2 19 respectively. A differential pressure transmitter 5 is installed on the three-valve group 8. The pressure difference on both sides of the porous orifice plate 2 is measured by the differential pressure transmitter 5, which is referred to as the porous orifice plate differential pressure.

[0044] A pressure hole 3 16 is provided on the measuring tube 1 at the front end of the V-cone throttling piece 3, and a pressure hole 4 17 is provided on the measuring tube 1 above the V-cone throttling piece 3. The pressure hole 3 16 and the pressure hole 4 17 are connected to the three-valve group 2 9 through the pressure tube 3 20 and the pressure tube 4 21 respectively. The differential pressure transmitter 2 6 is installed on the three-valve group 2 9, and the pressure difference on both sides of the V-cone throttling piece 3 is measured by the differential pressure transmitter 2 6, which is referred to as the V-cone differential pressure. The pressure tube 4 21 enters the front end of the V-cone throttling piece 3 from the pressure hole 4 17 and extends into the center of the tail end, so that the pressure at the center of the tail end of the V-cone throttling piece 3 can be measured, and the measurement is more accurate.

[0045] like Figure 2 As shown, the porous plate 2 is a circular plate with multiple holes distributed on it, which is installed in the middle of the measuring tube 1 through the screw mounting holes 13 on the flange 12. When the fluid flows through the porous plate 2, it passes through the holes on the porous plate 2, so that the fluid will form a pressure difference on both sides of the porous plate 2.

[0046] like Figure 3 As shown, the V-cone throttling piece 3 is composed of a straight pipe section and a V-cone body, and is a solid structure. It is supported and installed in the middle of the measuring tube 1 through the pressure taking pipe 21. When the fluid flows through the V-cone throttling piece 3, it will bypass the V-cone throttling piece 3 and flow through its periphery, thus forming a pressure difference on both sides of the V-cone throttling piece 3. Due to the different structures of the porous orifice plate 2 and the V-cone throttling piece 3, the pressure difference generated by the fluid flowing through the two throttling pieces is also different.

[0047] The three-valve group 1 8 and the three-valve group 2 9 are mainly composed of a valve body, two stop valves and a balance valve. The two stop valves: usually called high-pressure valves and low-pressure valves, are used to control the flow of media into or out of the positive and negative pressure chambers of the differential pressure transmitter. Balance valve: used to balance the pressure of the positive and negative pressure chambers to prevent damage to the differential pressure transmitter due to excessive pressure difference during installation or removal.

[0048] The pressure transmitter 4, differential pressure transmitter one 5, differential pressure transmitter two 6, and temperature transmitter 7 are respectively connected to the industrial computer 11. The pressure transmitter 4, differential pressure transmitter one 5, differential pressure transmitter two 6, and temperature transmitter 7 can upload the measured pressure in the measuring tube, the porous orifice plate differential pressure, the V-cone differential pressure, and the temperature in the measuring tube to the industrial computer 11 in real time.

[0049] In the above embodiment, pressure taking valves 10 are provided on pressure taking pipe 1 18 , pressure taking pipe 2 19 , pressure taking pipe 3 20 and pressure taking pipe 4 21 . When measurement is required, the pressure taking valves 10 are opened, and after the measurement is completed, the pressure taking valves 10 are closed.

[0050] The present invention also discloses a dual differential pressure wet gas flow measurement method, which uses the dual differential pressure wet gas flow measurement device as above, and comprises the following steps:

[0051] Step 1: Use a standard gas flowmeter and a standard liquid flowmeter to measure the mass flow rate of the gas phase and the mass flow rate of the liquid phase respectively, and obtain a standard value of the gas flow rate and a standard value of the liquid flow rate.

[0052] Step 2, the gas phase and liquid phase flowing through the standard gas flowmeter and the standard liquid flowmeter are mixed into wet gas and then passed into a horizontally placed dual differential pressure wet gas flow measurement device, and the pressure in the measuring tube, the porous orifice plate differential pressure, the V-cone differential pressure and the temperature in the measuring tube are collected through the pressure transmitter 4, the differential pressure transmitter 1 5, the differential pressure transmitter 2 6, and the temperature transmitter 7.

[0053] Step 3, calculating the porous plate apparent mass flow rate, V-cone apparent mass flow rate and gas phase density through the collected data.

[0054] The specific method is as follows:

[0055] First, the gas phase density ρ is calculated by using the temperature T and pressure P in the pipeline output by the temperature transmitter 7 and the pressure transmitter 4.g :

[0056]

[0057] Then, the apparent mass flow rate m of the porous plate is calculated by the differential pressure value output by differential pressure transmitter 1 5 and differential pressure transmitter 2 6. gApparentO and V-cone apparent mass flow rate m gApparentV :

[0058]

[0059]

[0060] Among them, Δp O , Δp V are the differential pressure values ​​output by differential pressure transmitter 1 5 and differential pressure transmitter 2 6, C is the outflow coefficient, β o , β V are the aperture ratios of the porous orifice plate and the V-cone throttling element 3, ε O , ε V are the expansion coefficients of the porous plate and the V-cone throttling element 3, d o d V They are the converted diameters of the porous orifice plate and the V-cone throttling element 3 respectively.

[0061] Step 4, substitute the calculated porous plate apparent mass flow rate, V-cone apparent mass flow rate, gas phase density and known parameters into the correction model, fit them with the standard values ​​of gas phase flow rate and liquid phase flow rate, and calculate the constants in the correction model.

[0062] The revised model is as follows:

[0063]

[0064] Among them, Or O It is the false high value of differential pressure transmitter 15 when the humid air flows through. m g is the standard value of gas phase flow rate, m gApparentO is the apparent mass flow rate of the porous plate; X LM 、Dr、Fr g are several dimensionless parameters describing the characteristics of moisture, among which X LM is the pressure drop ratio between the gas phase and the liquid phase, that is m l is the standard value of liquid phase flow rate, ρ g is the gas phase density, ρ l is the liquid phase density; Dr is the gas-liquid density ratio, that is Fr g It is used to characterize the relative magnitude of inertial force and gravity in fluid flow, that is, A, B, D, E, F, G, H are constants, Or V It is the false high value of differential pressure transmitter 26 when the humid air flows through. m gApparentV is the V-cone apparent mass flow rate.

[0065] Step 5, substituting the calculated constants into the correction model to obtain the metering model of the dual differential pressure wet gas flow measurement device.

[0066] Step 6. During the actual measurement process, the dual differential pressure wet gas flow measurement device is placed horizontally and installed on the equipment production pipeline through a flange. The porous orifice plate differential pressure, V-cone differential pressure and the temperature in the measuring tube are collected to calculate the porous orifice plate apparent mass flow, V-cone apparent mass flow and gas phase density. The calculated porous orifice plate apparent mass flow, V-cone apparent mass flow and gas phase density are substituted into the metering model, and the actual gas phase mass flow and liquid phase mass flow of the equipment production pipeline are obtained by solving the Newton iteration method.

[0067] The Newton iteration method uses the tangent line on the function curve to gradually approximate the root of the equation. First, an initial guess value for the root of the equation is required. The initial point is the value at which the gas-liquid phase mass flow rate iteration starts. m l0 is the initial value of liquid mass flow rate, m g0 is the initial value of gas phase mass flow rate.

[0068] When solving nonlinear equations, the Newton iteration method expands its application range by establishing the Jacobian Matrix, so that it can handle multivariable functions. The Jacobian matrix is ​​a matrix in which the first-order partial derivatives of a function are arranged in a certain way. It reflects the optimal linear approximation of a differentiable equation to a given point, similar to the derivative of a multivariate function, starting from the initial guess value. Start by calculating the next approximate value through the iterative formula Then use calculate And so on, until the change of the approximation value is very small or reaches the predetermined accuracy ε, when The output after the condition is the gas-liquid phase mass flow rate.

[0069] The measuring device of this embodiment is used to measure a mixture of air and water. The pressure range is 100kpa-400kpa, the gas phase mass flow range is 73kg / h-300kg / h, and the liquid phase mass flow range is 70kg / h-1130kg / h. There are 600 groups of experimental points in total. Through these experimental points, various parameters in the correction model are determined to obtain the metering model of the dual differential pressure wet gas flow measurement device, and the model is written into the industrial computer. Install the dual differential pressure wet gas flow measurement device on the experimental pipeline, turn on the industrial computer and the pressure transmitter, differential pressure transmitter 1, differential pressure transmitter 2, and temperature transmitter, and pass the mixture of air and water into the metering pipeline. The industrial computer receives the pressure, porous orifice plate differential pressure, V-cone differential pressure and temperature signals, and inputs the signals into the metering model to finally obtain the gas phase mass flow rate and liquid phase mass flow rate. In actual measurement, such as Figure 4 and Figure 5 As shown, the relative error of the gas phase flow rate is within ±4%, with a confidence level of 98%, and the relative error of the liquid phase flow rate is within ±9%, with a confidence level of 96%.

[0070] Compared with the measurement of wet gas by gas phase flow meter, this method has a wider measurement range and can measure both gas and liquid phases of wet gas at the same time with high measurement accuracy.

[0071] Compared with other standard differential pressure flowmeter combinations, the throttling structure used in this method has a higher range ratio and a shorter straight pipe section. The equipment structure is smaller, the accuracy is high, the cost is lower, and it is more suitable for wellhead metering conditions.

[0072] Compared with the method of combining a differential pressure flowmeter with a phase content detection device, this method does not require investment in radiation protection and maintenance, and the cost is also lower.

[0073] The present invention establishes a dual differential pressure wet gas flow metering model based on a porous orifice plate-V cone throttling element, and adopts Newton iteration method to solve the model to obtain the gas-liquid phase mass flow rate, which has faster calculation speed, high model accuracy and strong adaptability to different working conditions.

[0074] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A dual differential pressure wet gas flow measurement device, characterized in that: It comprises a measuring tube, wherein a pressure transmitter is installed upstream of the measuring tube; a porous plate and a V-cone throttling piece are installed in the middle of the measuring tube, a pressure hole 1 and a pressure hole 2 are provided on the measuring tubes on both sides of the porous plate, the pressure hole 1 and the pressure hole 2 are connected to a three-valve group 1 through a pressure tube 1 and a pressure tube 2 respectively, and a differential pressure transmitter 1 is installed on the three-valve group 1; a pressure hole 3 is provided on the measuring tube at the front end of the V-cone throttling piece, a pressure hole 4 is provided on the measuring tube above the V-cone throttling piece, the pressure hole 3 and the pressure hole 4 are connected to a three-valve group 2 through a pressure tube 3 and a pressure tube 4 respectively, and a differential pressure transmitter 2 is installed on the three-valve group 2, and the pressure tube 4 enters the front end of the V-cone throttling piece from the pressure hole 4 and extends into the center of the tail end; a temperature transmitter is installed downstream of the measuring tube; the pressure transmitter, the differential pressure transmitter 1, the differential pressure transmitter 2, and the temperature transmitter are respectively connected to an industrial computer.

2. A dual differential pressure wet gas flow measurement device according to claim 1, characterized in that: Pressure taking valves are arranged on the pressure taking pipe 1, the pressure taking pipe 2, the pressure taking pipe 3 and the pressure taking pipe 4.

3. A dual differential pressure wet gas flow measurement method, using a dual differential pressure wet gas flow measurement device as claimed in claim 2, characterized in that: The steps include: Step 1, using a standard gas flowmeter and a standard liquid flowmeter to measure the mass flow rate of the gas phase and the mass flow rate of the liquid phase respectively, to obtain a standard value of the gas phase flow rate and a standard value of the liquid phase flow rate; Step 2, the gas phase and liquid phase flowing through the standard gas flowmeter and the standard liquid flowmeter are mixed into wet gas and then passed into a horizontally placed dual differential pressure wet gas flow measurement device, and the pressure in the measuring tube, the multi-hole orifice plate differential pressure, the V-cone differential pressure and the temperature in the measuring tube are collected through the pressure transmitter, the differential pressure transmitter 1, the differential pressure transmitter 2 and the temperature transmitter; Step 3, calculating the porous plate apparent mass flow rate, V-cone apparent mass flow rate and gas phase density through the collected data; Step 4, substituting the calculated porous plate apparent mass flow rate, V-cone apparent mass flow rate, gas phase density and known parameters into the correction model, fitting them with the standard value of gas phase flow rate and the standard value of liquid phase flow rate, and calculating the constants in the correction model; Step 5, substituting the calculated constants into the correction model to obtain a metering model of the dual differential pressure wet gas flow measurement device; Step 6. During the actual measurement process, the dual differential pressure wet gas flow measurement device is placed horizontally and installed on the equipment production pipeline through a flange. The porous orifice plate differential pressure, V-cone differential pressure and the temperature in the measuring tube are collected to calculate the porous orifice plate apparent mass flow, V-cone apparent mass flow and gas phase density. The calculated porous orifice plate apparent mass flow, V-cone apparent mass flow and gas phase density are substituted into the metering model, and the actual gas phase mass flow and liquid phase mass flow of the equipment production pipeline are obtained by solving the Newton iteration method.

4. A dual differential pressure wet gas flow measurement method according to claim 3, characterized in that: The specific method of step 3 is as follows: First, the gas phase density ρ is calculated by using the temperature T and pressure P in the pipeline output by the temperature transmitter and the pressure transmitter. g : Then, the apparent mass flow rate m of the porous plate is calculated by the differential pressure value output by differential pressure transmitter 1 and differential pressure transmitter 2. gApparentO and V-cone apparent mass flow rate m gApparentV : Among them, Δp O , Δp V are the differential pressure values ​​output by differential pressure transmitter 1 and differential pressure transmitter 2, C is the outflow coefficient, β o , β V are the aperture ratios of the porous orifice plate and the V-cone throttling element, ε O , ε V are the expansion coefficients of the porous orifice plate and the V-cone throttling element, d o d V They are the converted diameters of the porous orifice plate and the V-cone throttling element respectively.

5. A dual differential pressure wet gas flow measurement method according to claim 3, characterized in that: In step 4, the correction model is as follows: Among them, Or O It is the false high value of the differential pressure transmitter when the humid air flows through. m g is the standard value of gas phase flow rate, m gApparentO is the apparent mass flow rate of the porous plate; X LM 、Dr、Fr g are several dimensionless parameters describing the characteristics of moisture, among which X LM is the pressure drop ratio between the gas phase and the liquid phase, that is m l is the standard value of liquid phase flow rate, ρ g is the gas phase density, ρ l is the liquid phase density; Dr is the gas-liquid density ratio, that is Fr g It is used to characterize the relative magnitude of inertial force and gravity in fluid flow, that is, A, B, D, E, F, G, H are constants, Or V It is the false high value of differential pressure transmitter 2 when the humid air flows through. m gApparentV is the V-cone apparent mass flow rate.

Images