Early warning device for liquid surge entrainment in gas pipeline

Abstract

The application discloses a kind of early warning devices of gas transmission pipeline liquid sudden increase entrainment, including top pressure pipe, bottom pressure pipe, differential pressure transmitter, data processing terminal and early warning equipment, the input end of top pressure pipe is communicated with the top end of gas transmission pipeline, the input end of bottom pressure pipe is communicated with the bottom end of gas transmission pipeline;The output end of top pressure pipe and the output end of bottom pressure pipe are connected with differential pressure transmitter respectively, and differential pressure transmitter is used to monitor the parameter of fluid in top pressure pipe and bottom pressure pipe;Differential pressure transmitter is connected with data processing terminal, and data processing terminal is used to process the parameter of fluid obtained by differential pressure transmitter monitoring, obtains differential pressure value, and compares differential pressure value with preset value;Early warning equipment is connected with data processing terminal;When differential pressure value is greater than preset value, data processing terminal transmits signal to early warning equipment, and early warning equipment alarms.It can solve the problem that existing early warning device cannot timely and accurately early warn liquid inclusion condition.

Description

Technical Field

[0001] This invention relates to the field of pipeline defect monitoring and simulation technology, specifically to an early warning device for sudden liquid entrainment in gas transmission pipelines. Background Technology

[0002] Gas pipelines are used extensively in the production processes of natural gas extraction, transportation, purification, and sales. These pipelines are designed for gas transport. Although a small amount of liquid may inevitably be mixed in with the gas, this liquid can generally be removed through technical means.

[0003] There is a risk that unconventional operations upstream may cause a large amount of liquid to be carried into the gas pipeline. If the liquid is not removed in time, it may be carried into the downstream user's production equipment, which will seriously affect the normal production of the downstream user and even cause safety hazards.

[0004] In order to remove liquid inclusions in a timely manner, an effective early warning device is needed. Existing early warning devices cannot provide timely and accurate warnings for situations involving large amounts of liquid inclusions. Summary of the Invention

[0005] The purpose of this invention is to provide an early warning device for sudden liquid entrainment in gas pipelines, solving the problem that existing early warning devices cannot provide timely and accurate warnings of liquid entrainment.

[0006] This invention is achieved through the following technical solution:

[0007] An early warning device for sudden liquid entrainment in a gas pipeline includes: a top pressure tap and a bottom pressure tap, wherein the input end of the top pressure tap is connected to the top of the gas pipeline, and the input end of the bottom pressure tap is connected to the bottom of the gas pipeline; a differential pressure transmitter, wherein the output ends of the top and bottom pressure taps are respectively connected to the differential pressure transmitter, and the connection point between the bottom pressure tap and the differential pressure transmitter is positioned lower than the bottom of the gas pipeline; the differential pressure transmitter is used to monitor fluid parameters within the top and bottom pressure taps; a data processing terminal, wherein the differential pressure transmitter is connected to the data processing terminal, and the data processing terminal is used to process the fluid parameters monitored by the differential pressure transmitter to obtain a differential pressure value, and compare the differential pressure value with a preset value; and an early warning device, wherein the early warning device is connected to the data processing terminal; when the differential pressure value exceeds the preset value, the data processing terminal transmits a signal to the early warning device, and the early warning device triggers an alarm; based on the gas pipeline... A method for an early warning device for a sudden increase in liquid entrainment in a pipeline includes the following steps: connecting the input end of the top pressure tap and the input end of the bottom pressure tap to the top and bottom ends of the gas pipeline, respectively; determining the calculation formula for the differential pressure value and inputting the calculation formula into the data processing terminal; setting the preset value in the data processing terminal according to the fluid conditions in the gas pipeline; when the early warning device alarms, disconnecting the top pressure tap or the bottom pressure tap from the differential pressure transmitter and utilizing the flow in the gas pipeline... The pressure difference between the gas and the outside environment flushes the accumulated liquid and dirt in the disassembled top or bottom pressure taps to the outside. After flushing, the disassembled top or bottom pressure taps are reconnected to the differential pressure transmitter. Under abnormal conditions, the calculation formula is: ΔP = R × Δρ × ΔH; where: ΔP is the differential pressure value; R is an empirical constant; Δρ is the density of the gas-liquid mixture in the gas pipeline under abnormal conditions; and ΔH is the liquid accumulation height in the gas pipeline under normal and abnormal conditions.

[0008] Optionally, the differential pressure transmitter is detachably connected to the top pressure tap and the bottom pressure tap.

[0009] Optionally, the detachable connection is a threaded connection or a flange connection.

[0010] Optionally, the top pressure pipe and the bottom pressure pipe are respectively provided with a top valve and a bottom valve.

[0011] Optionally, the differential pressure transmitter is connected to the data processing terminal via a cable, or the differential pressure transmitter is connected to the data processing terminal via a network signal.

[0012] Optionally, the data processing terminal is a server or a PLC.

[0013] Optionally, the method based on the early warning device for sudden liquid entrainment in the gas pipeline further includes the following steps:

[0014] Under normal operating conditions, the calculation formula is:

[0015] Under normal operating conditions, the calculation formula is:

[0016] ΔΡ=ρ1×H1×g-ρ1×H2×g=0;

[0017] in:

[0018] ΔP is the pressure difference value;

[0019] ρ1 is the density of the fluid in the gas pipeline under normal operating conditions;

[0020] H1 is the height of the fluid inside the bottom pressure tapping tube;

[0021] H2 is the height of the fluid inside the top pressure tapping tube;

[0022] G is the acceleration due to gravity.

[0023] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0024] The early warning device for sudden liquid entrainment in gas pipelines provided in this embodiment uses a top pressure tap and a bottom pressure tap, connected to the top and bottom of a vertically installed gas pipeline, respectively. These pipes direct fluid from both ends of the pipeline to a differential pressure transmitter. The bottom pressure tap is positioned at a lower height than the bottom of the pipeline. Utilizing the density difference between the top and bottom of the pipeline and the principle of communicating vessels, a pressure difference is created between the two ends of the transmitter. The transmitter contains a detection diaphragm; fluid from both ends of the pipeline is directed to the two ends of the diaphragm, causing deformation due to the pressure difference. A data processing terminal generates an electrical signal from the deformation of the diaphragm, producing the differential pressure value. This signal is transmitted to the data processing terminal, which processes the fluid parameters using a specific formula. By comparing the differential pressure value with a preset value, a precise alarm is provided. Based on this, by setting up an early warning device, when the differential pressure value exceeds the preset value, the early warning device will promptly alarm, thus accurately and timely identifying the problem of a large amount of liquid entrainment exceeding the threshold. This allows maintenance personnel to promptly remove liquid entrainment in the gas pipeline. Furthermore, by setting the connection height between the bottom pressure tap and the differential pressure transmitter to be lower than the bottom of the gas pipeline, when a large amount of gas-liquid mixture suddenly accumulates at the connection between the bottom pressure tap and the differential pressure transmitter under abnormal operating conditions, the normal operating condition fluid gas inside the top pressure tap can be discharged into the gas pipeline due to gravity. This ensures that the fluids measured by the differential pressure transmitter inside the top and bottom pressure taps are the normal operating condition fluid and the abnormal operating condition fluid, respectively, avoiding mixing and thus avoiding measurement errors. Through the cooperation of the above features, this early warning device for sudden increase in liquid entrainment in gas pipelines can effectively solve the problem that existing early warning devices cannot provide timely and accurate early warning of liquid entrainment. Attached Figure Description

[0025] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0026] Figure 1 This is a schematic diagram of an early warning device for sudden liquid entrainment in a gas pipeline provided in an embodiment of the present invention.

[0027] The attached diagram shows the markings and corresponding component names:

[0028] 1-Gas transmission pipeline; 10-Top pressure tap; 101-Top valve; 11-Bottom pressure tap; 111-Bottom valve; 20-Differential pressure transmitter; 30-Data processing terminal; 40-Early warning equipment. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0030] First, it should be noted that under normal operating conditions, the gaseous fluid in the gas pipeline 1 contains a small amount of liquid. Under the influence of gravity, the liquid slowly accumulates at the bottom of the gas pipeline 1, forming stagnant liquid and contaminants. This results in the fluid density at the bottom of the gas pipeline 1 being greater than that at the top, causing the pressure difference to increase slowly. Under abnormal operating conditions, the fluid inside the gas pipeline 1 suddenly carries a large amount of liquid, rapidly changing from a gaseous phase to a gas-liquid mixture. This causes a sudden and sharp increase in the fluid density at the bottom of the gas pipeline 1, resulting in a sharp increase in the pressure difference. Therefore, the pressure difference can accurately and effectively characterize the degree of liquid entrainment.

[0031] Please refer to Figure 1 This invention provides an early warning device for sudden liquid entrainment in a gas pipeline, comprising: a top pressure tapping pipe 10 and a bottom pressure tapping pipe 11, wherein the input end of the top pressure tapping pipe 10 is connected to the top end of the gas pipeline 1, and the input end of the bottom pressure tapping pipe 11 is connected to the bottom end of the gas pipeline 1; secondly, a differential pressure transmitter 20 is provided, wherein the output ends of the top pressure tapping pipe 10 and the bottom pressure tapping pipe 11 are respectively connected to the differential pressure transmitter 20, and the connection point between the bottom pressure tapping pipe 11 and the differential pressure transmitter 20 is positioned lower than the bottom end of the gas pipeline 1. The differential pressure transmitter 20 is used to monitor the parameters of the fluid in the top pressure tap 10 and the bottom pressure tap 11; the third includes a data processing terminal 30, the differential pressure transmitter 20 is connected to the data processing terminal 30, the data processing terminal is used to process the parameters of the fluid monitored by the differential pressure transmitter 20, obtain the differential pressure value, and compare the differential pressure value with a preset value; the fourth includes an early warning device 40, the early warning device 40 is connected to the data processing terminal 30; when the differential pressure value is greater than the preset value, the data processing terminal transmits a signal to the early warning device 40, and the early warning device 40 alarms.

[0032] The early warning device for sudden liquid entrainment in a gas pipeline provided in this embodiment uses a top pressure pipe 10 and a bottom pressure pipe 11, which are respectively connected to the top and bottom of a vertically installed gas pipeline 1 under test. These pipes guide the fluid from both ends of the gas pipeline 1 to a differential pressure transmitter 20. The connection point between the bottom pressure pipe 11 and the differential pressure transmitter 20 is positioned lower than the bottom of the gas pipeline 1. Utilizing the difference in fluid density between the top and bottom ends of the gas pipeline 1 and the principle of communicating vessels, a pressure difference is created between the two connection points of the differential pressure transmitter 20. The differential pressure transmitter 20 contains a detection diaphragm. The fluid from both ends of the gas pipeline 1 is guided to the two ends of the detection diaphragm, forcing the diaphragm to deform due to the pressure difference. A data processing terminal 30 is used. The deformation of the detection diaphragm in the differential pressure transmitter 20 generates a corresponding electrical signal, resulting in a differential pressure value, which is transmitted to the data processing terminal 30. The data processing terminal processes the fluid parameters using a specific formula and provides an accurate warning by comparing the differential pressure value with a preset value. The system includes a warning node; based on this, by setting up an early warning device 40, when the differential pressure value exceeds the preset value, the early warning device 40 will promptly sound an alarm, which can promptly and accurately detect the problem of a large amount of liquid entrainment exceeding the threshold, and can promptly guide maintenance personnel to remove the liquid entrainment in the gas transmission pipeline 1. Furthermore, by setting the connection height between the bottom pressure tap 11 and the differential pressure transmitter 20 to be lower than the bottom of the gas transmission pipeline 1, when a large amount of gas-liquid mixture suddenly accumulates at the connection between the bottom pressure tap 11 and the differential pressure transmitter 20 under abnormal operating conditions, the normal operating condition fluid gas inside the top pressure tap 10 can be discharged into the gas transmission pipeline 1 due to gravity, ensuring that the fluid inside the top pressure tap 10 and the bottom pressure tap 11 measured by the differential pressure transmitter 20 are the normal operating condition fluid and the abnormal operating condition fluid, respectively, avoiding the mixing of the two and thus avoiding measurement errors. Through the cooperation of the above features, the early warning device for sudden increase in liquid entrainment in the gas transmission pipeline can effectively solve the problem that existing early warning devices cannot provide timely and accurate warnings of liquid entrainment.

[0033] It should be noted that the differential pressure transmitter 20 does not require the addition of isolation fluid. Instead, it uses the pressure difference (density difference) combined with the principle of communicating vessels to force the deformation of the internal detection diaphragm to characterize the pressure difference value.

[0034] It should be noted that the data processing terminal 30 mentioned above can be any of the relevant products in the existing technology, as long as it can receive data signals and process, calculate and compare the data signals.

[0035] It should be noted that the aforementioned early warning device 40 can be any of the relevant products in the existing technology, as long as it can receive signals and perform physical representation based on the signals, such as flashing lights, sound emission, image display, digital display, etc.

[0036] In order for maintenance personnel to promptly remove accumulated liquid and dirt from the top pressure pipe 10 or the bottom pressure pipe 11, the differential pressure transmitter 20 is detachably connected to the top pressure pipe 10 and the bottom pressure pipe 11.

[0037] Preferably, the detachable connection is a threaded connection or a flange connection.

[0038] In other embodiments, a centrally located drain valve and drain pipe design can be used to drain the accumulated liquid and dirt inside the pipe without disassembly.

[0039] To facilitate smoother sewage discharge operations, the top pressure pipe 10 and the bottom pressure pipe 11 are respectively equipped with a top valve 101 and a bottom valve 111.

[0040] By setting the top valve 101 and the bottom valve 111, the drainage, maintenance or commissioning is not restricted by whether there is fluid passing through the gas pipeline 1.

[0041] It should be noted that the differential pressure transmitter 20 is connected to the data processing terminal 30 via a cable, or the differential pressure transmitter 20 is connected to the data processing terminal 30 via a network signal.

[0042] Preferably, the data processing terminal 30 is a server or a PLC.

[0043] The present invention also provides a method for early warning of sudden liquid entrainment in a gas pipeline, which employs any of the above-mentioned early warning devices for sudden liquid entrainment in the gas pipeline 1, and includes the following steps:

[0044] S1. Connect the input end of the top pressure pipe 10 and the input end of the bottom pressure pipe 11 to the top and bottom ends of the gas transmission pipeline 1, respectively.

[0045] S2. Determine the calculation formula for the differential pressure value and input the calculation formula into the data processing terminal 30;

[0046] S3. Set the preset value in the data processing terminal according to the fluid conditions in the gas pipeline 1;

[0047] S4. When the warning device 40 alarms, the top pressure pipe 10 or the bottom pressure pipe 11 is separated from the differential pressure transmitter 20, and the accumulated liquid and dirt in the separated top pressure pipe 10 or bottom pressure pipe 11 are flushed to the outside by the pressure difference between the fluid in the gas pipeline 1 and the outside.

[0048] S5. After flushing, reconnect the disassembled top pressure pipe 10 or bottom pressure pipe 11 to the differential pressure transmitter 20.

[0049] Conventional use of differential pressure transmitters requires the addition of a release fluid. This method, however, does not require the release fluid and instead uses the differential pressure transmitter to measure the differential pressure value. It utilizes the principle that the difference in fluid density within the gas pipeline under normal and abnormal operating conditions creates differential pressure. Based on the differential pressure transmitter's measurement values, it calculates the relationship between fluid density and liquid accumulation in the pipeline under abnormal conditions, providing early warning of abnormal operating conditions.

[0050] ρ1 is the density of the gas phase fluid in the gas transmission pipeline under normal operating conditions, and ρ2 is the density of the liquid phase fluid in the gas-liquid mixture that may be entrained in the gas transmission pipeline under abnormal operating conditions; H1 is the height of the fluid in the bottom pressure tap 11, and H2 is the height of the fluid in the top pressure tap 10.

[0051] Under normal operating conditions, the fluid density in both the top and bottom pressure taps is ρ1, and the fluid height in both pipes is 0. Under abnormal operating conditions, due to gravity, the height of the gas-liquid mixture increases from 0, and the fluid in the bottom pressure tap gradually changes from a gaseous fluid under normal conditions to a gas-liquid mixture. The density of the gas-liquid mixture is Δρ, which is between the gaseous fluid density ρ1 under normal operating conditions and the liquid fluid density ρ2 under abnormal operating conditions. The fluid density in the top pressure tap is ρ1, and the fluid height H1 in the bottom pressure tap 11 begins to increase. When the gas-liquid mixture does not completely fill the gas transmission pipeline, the fluid height H2 in the top pressure tap 10 is normally 0.

[0052] In daily management, due to the influence of gravity, trace amounts of liquid substances entrained in the gas pipeline will gradually deposit in the bottom pressure tapping pipe, and the values ​​of H1 and H2 will slowly increase under normal operating conditions. Based on user requirements, a maintenance value 'a' is set. When the measured value ΔP ≥ a, liquid is drained from both the top and bottom pressure tapping pipes to maintain H1 and H2 at a normal level of 0.

[0053] The main feature of this method is that, based on the medium, pipe diameter, pressure, etc. of the user's gas transmission pipeline, an empirical constant R is calculated. Based on the measured value ΔP, the relationship between the fluid density and the liquid accumulation height in the gas transmission pipeline is calculated using a formula to estimate the degree of liquid entrainment in the fluid in the gas transmission pipeline. According to the user's needs, a warning value b is determined, and a warning is issued when ΔP ≥ b.

[0054] Under normal operating conditions, the calculation formula is:

[0055] ΔΡ=ρ1×H1×g-ρ1×H2×g=0;

[0056] in:

[0057] ΔP is the pressure difference value; ρ1 is the density of the fluid in the gas transmission pipeline 1 under normal operating conditions; H1 is the height of the fluid in the bottom pressure tap 11; H2 is the height of the fluid in the top pressure tap 10; G is the acceleration due to gravity.

[0058] Under abnormal operating conditions, the calculation formula is as follows:

[0059] ΔP = R × Δρ × ΔH;

[0060] in:

[0061] ΔP is the pressure difference value; R is an empirical constant; Δρ is the density of the gas-liquid mixture in the gas pipeline 1 under abnormal operating conditions; ΔH is the liquid accumulation height of the fluid in the gas pipeline 1 under normal and abnormal operating conditions.

[0062] It should be noted that the preset values ​​can be set according to the actual needs of the user, and different preset values ​​can be set for normal working conditions and abnormal working conditions, and displayed separately at 40 warning devices.

[0063] It should be noted that the R value is determined based on the differential pressure gauge specifications, pipe diameter, fluid density, fluid flow rate, pipe pressure, and other parameters, combined with experience and specific experimental requirements.

[0064] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A warning device for sudden liquid entrainment in a gas pipeline, characterized in that, include: The top pressure pipe (10) and the bottom pressure pipe (11) are connected, with the input end of the top pressure pipe (10) connected to the top end of the gas pipeline and the input end of the bottom pressure pipe (11) connected to the bottom end of the gas pipeline. Differential pressure transmitter (20), the output end of the top pressure pipe (10) and the output end of the bottom pressure pipe (11) are respectively connected to the differential pressure transmitter (20), the connection point of the bottom pressure pipe (11) and the differential pressure transmitter (20) is set at a height lower than the bottom end of the gas pipeline, the differential pressure transmitter (20) is used to monitor the parameters of the fluid in the top pressure pipe (10) and the bottom pressure pipe (11); Data processing terminal (30), the differential pressure transmitter (20) is connected to the data processing terminal (30), the data processing terminal is used to process the parameters of the fluid monitored by the differential pressure transmitter (20), obtain the differential pressure value, and compare the differential pressure value with a preset value; Early warning device (40), the early warning device (40) is connected to the data processing terminal (30); When the differential pressure value is greater than the preset value, the data processing terminal transmits a signal to the early warning device (40), and the early warning device (40) alarms. The method based on the early warning device for sudden liquid entrainment in the gas pipeline includes the following steps: The input end of the top pressure pipe (10) and the input end of the bottom pressure pipe (11) are connected to the top and bottom ends of the gas transmission pipeline, respectively. Determine the calculation formula for the differential pressure value and input the calculation formula into the data processing terminal (30). The preset value is set at the data processing terminal based on the fluid conditions inside the gas pipeline. When the warning device (40) alarms, the top pressure pipe (10) or the bottom pressure pipe (11) is separated from the differential pressure transmitter (20), and the accumulated liquid and dirt in the top pressure pipe (10) or the bottom pressure pipe (11) after separation are flushed to the outside by the pressure difference between the fluid in the gas pipeline and the outside. After flushing, the disassembled top pressure tube (10) or bottom pressure tube (11) is reconnected to the differential pressure transmitter (20); Under abnormal operating conditions, the calculation formula is as follows: ΔP = R × Δρ × ΔH; in: ΔP is the pressure difference value; R is an empirical constant; Δρ is the density of the gas-liquid mixture in the gas pipeline under abnormal operating conditions; ΔH represents the liquid accumulation height of the fluid in the gas transmission pipeline under normal and abnormal operating conditions.

2. The early warning device for sudden liquid entrainment in gas pipelines according to claim 1, characterized in that, The differential pressure transmitter (20) is detachably connected to the top pressure tap (10) and the bottom pressure tap (11).

3. The early warning device for sudden liquid entrainment in gas pipelines according to claim 2, characterized in that, The detachable connection is either a threaded connection or a flange connection.

4. The early warning device for sudden liquid entrainment in gas pipelines according to claim 1, characterized in that, The top pressure pipe (10) and the bottom pressure pipe (11) are respectively equipped with a top valve (101) and a bottom valve (111).

5. The early warning device for sudden liquid entrainment in gas pipelines according to claim 1, characterized in that, The differential pressure transmitter (20) is connected to the data processing terminal (30) via a cable, or the differential pressure transmitter (20) is connected to the data processing terminal (30) via a network signal.

6. The early warning device for sudden liquid entrainment in gas pipelines according to claim 1, characterized in that, The data processing terminal (30) is a server or a PLC.

7. The early warning device for sudden liquid entrainment in gas pipelines according to claim 1, characterized in that, The method based on the early warning device for sudden liquid entrainment in the gas pipeline further includes the following steps: Under normal operating conditions, the calculation formula is: ΔΡ=ρ1×H1×g-ρ1×H2×g=0; in: ΔP is the pressure difference value; ρ1 is the density of the fluid in the gas pipeline under normal operating conditions; H1 is the height of the fluid inside the bottom pressure tap (11); H2 is the height of the fluid inside the top pressure tap (10); G is the acceleration due to gravity.

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