A combined anti-blocking system for flow measurement

Abstract

The utility model relates to a composite anti-blocking system for flow measurement, belonging to the technical field of pipeline flow measurement. It aims to solve the problem that the existing differential pressure type, thermal type gas mass flowmeter and the like are blocked in pressure tapping hole, pressure tapping pipe or differential pressure sensor instrument pipe due to the impurities such as gravel, coal ash and industrial dregs contained in industrial pipeline medium, leading to instrument failure or inaccurate measurement. The system comprises a three-valve group, a flowmeter, a control module, an upper computer and two groups of air sources; one side of the three-valve group is sealingly communicated with a differential pressure sensor, the positive pressure end and the negative pressure end of the flowmeter are respectively connected to the two ends of the three-valve group through the instrument air paths provided with positive pressure normally closed valves and negative pressure normally closed valves, the control module is connected to the normally closed valves and the upper computer through a control loop, and the two groups of air sources are respectively connected to the corresponding ends of the flowmeter through the pipelines provided with positive pressure hand-operated valves and negative pressure hand-operated valves, and positive pressure normally open valves and negative pressure normally open valves can also be provided. The utility model is mainly used for pipeline flow measurement, preventing instrument and pipeline blockage and ensuring stable and accurate measurement.

Description

Technical Field

[0001] This utility model relates to the field of pipeline flow measurement technology, and in particular to a composite anti-clogging system for flow measurement. Background Technology

[0002] Currently, instruments widely used for pipeline flow measurement mainly include differential pressure flow meters and thermal gas mass flow meters. These instruments typically require the installation of one or more pressure taps or sensor probes in the fluid pipeline to calculate the flow rate by detecting parameters such as fluid pressure and velocity.

[0003] In the current technological context, when using differential pressure flow meters to measure the flow rate of industrial pipelines, the measured medium contains various impurities, such as gravel, coal ash, and industrial slag, which may clog the pressure tapping holes or pipes of the flow meter, or even the instrument tube of the differential pressure sensor, leading to flow meter failure or inaccurate measurement.

[0004] Therefore, we propose a composite anti-clogging system for flow measurement. Utility Model Content

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a composite anti-clogging system for flow measurement.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A composite anti-clogging system for flow measurement includes:

[0008] A three-valve manifold, wherein one side of the three-valve manifold is sealed and connected to a differential pressure sensor;

[0009] The flow meter is located on one side of the three-valve manifold. Its positive pressure end is sealed and connected to one end of the three-valve manifold through an instrument air circuit equipped with a positive pressure normally closed valve, and its negative pressure end is sealed and connected to the other end of the three-valve manifold through an instrument air circuit equipped with a negative pressure normally closed valve.

[0010] The control module is located on one side of the instrument air circuit. Both the positive pressure normally closed valve and the negative pressure normally closed valve are connected to the control module through the control circuit.

[0011] The host computer is connected to the control module via a control loop;

[0012] Two sets of air sources: one set is connected to the positive pressure end of the flow meter through a pipeline equipped with a positive pressure manual adjustment valve, and the other set is connected to the negative pressure end of the flow meter through a pipeline equipped with a negative pressure manual adjustment valve.

[0013] The gas source outputs low-pressure airflow through positive pressure manual adjustment valve and negative pressure manual adjustment valve to purge the flow meter and instrument air path anti-blockage. The differential pressure signal collected by the differential pressure sensor is transmitted to the host computer through the control module.

[0014] In one possible design, a positive pressure normally open valve and a negative pressure normally open valve are also included. The positive pressure normally open valve is located in the pipeline between one set of gas sources and the instrument gas circuit, and the negative pressure normally open valve is located in the pipeline between the other set of gas sources and the instrument gas circuit.

[0015] In one possible design, the positive pressure normally closed valve, the negative pressure normally closed valve, the positive pressure normally open valve, and the negative pressure normally open valve are all solenoid valves.

[0016] In one possible design, the control module can detect changes in pipeline load and the output signal of the differential pressure sensor. When the pipeline load change is less than ±5%, and the duration of the continuous unidirectional change trend of the differential pressure sensor's output signal exceeds a preset threshold and the change amplitude is greater than twice the pipeline load change amplitude, the control module determines that there is a risk of blockage in the system and starts the cleaning mode.

[0017] In one possible design, the positive pressure normally closed valve, negative pressure normally closed valve, positive pressure normally open valve, negative pressure normally open valve, positive pressure manually adjustable valve, and negative pressure manually adjustable valve can be combined into an integral valve group for installation, or arranged separately and controlled independently according to the installation space and maintenance requirements.

[0018] Beneficial effects: In this utility model, with a pressurized air source, four control valves and two manual adjustment valves are used to provide two different air-blowing anti-clogging modes. In the operation state, it does not affect the normal flow measurement, and it can provide continuous air-blowing anti-clogging in the working state of the flow meter. It adopts two working states of normal low pressure + high pressure for clogging to blow out the blockage by increasing the air source pressure and using strong pressure bursting. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the gas path structure of a composite anti-clogging system for flow measurement proposed in this utility model.

[0020] Figure 2 This is a schematic diagram of the working mode 2 of a composite anti-blocking system for flow measurement proposed in this utility model.

[0021] In the diagram: 1. Differential pressure sensor; 2. Positive pressure normally closed valve; 3. Positive pressure normally open valve; 4. Positive pressure manual control valve; 5. Flow meter; 6. Negative pressure manual control valve; 7. Negative pressure normally open valve; 8. Control circuit; 9. Negative pressure normally closed valve; 10. Instrument air circuit; 11. Three-valve manifold; 12. Control module; 13. Air source; 14. Host computer. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0023] In one embodiment: Refer to Figures 1-2 A composite anti-clogging system includes a three-valve manifold 11. One side of the three-valve manifold 11 is sealed to a differential pressure sensor 1. During assembly, a seal is achieved by tightening the sealing ring with bolts to prevent media leakage from affecting the accuracy of differential pressure signal acquisition. Even if the media pressure fluctuates, a stable sealing state can be maintained. A flow meter 5 is installed on one side of the three-valve manifold 11. Its positive pressure end is connected to one end of the three-valve manifold 11 through an instrument air passage 10, on which a positive pressure normally closed valve 2 is installed. The negative pressure end of the flow meter 5 is connected to the other end of the three-valve manifold 11 through another instrument air passage 10 of the same specification, on which a negative pressure normally closed valve 9 is installed. These two valves control the opening and closing of the instrument air passage 10, thereby regulating the media flow between the flow meter 5 and the three-valve manifold 11.

[0024] The control module 12 is located on one side of the instrument air circuit 10, and its position should be chosen to facilitate the establishment of control connections with each valve. Both the positive pressure normally closed valve 2 and the negative pressure normally closed valve 9 are connected to the control module 12 via the control loop 8 to transmit signals and control commands. The host computer 14 is also connected to the control module 12 via the control loop 8. Various signals collected by the control module 12 can be uploaded to the host computer 14 in real time. Operators can view system operating parameters, including the data collected by the differential pressure sensor 1 and the on / off status of each valve, through the interface of the host computer 14. This eliminates the need for on-site inspection of each component's status, and the host computer 14 can be replaced by a DCS (Distributed Control System).

[0025] The system is equipped with two sets of air sources 13, providing low-pressure airflow to the positive and negative pressure ends of the flow meter 5, respectively. One set of air sources 13 is connected to the positive pressure end of the flow meter 5 via a pipeline, on which a positive pressure manual adjustment valve 4 is installed. The operator can rotate the valve stem of the positive pressure manual adjustment valve 4 to adjust the airflow pressure and flow rate. The other set of air sources 13 is connected to the negative pressure end of the flow meter 5 via another pipeline, on which a negative pressure manual adjustment valve 6 is installed. The adjustment method is the same as that of the positive pressure manual adjustment valve 4. During normal operation, the air source 13 continuously outputs low-pressure airflow. The airflow enters the flow meter 5 through the pipeline, and then flows along the instrument air passage 10, purging the measuring channel of the flow meter 5 and the inner wall of the instrument air passage 10 to remove any dust and impurities that may be attached.

[0026] To improve the stability of the airflow supply, the system is also equipped with a positive pressure normally open valve 3 and a negative pressure normally open valve 7. The positive pressure normally open valve 3 is installed on the pipeline connecting the air source 13 and the instrument air circuit 10, specifically between the positive pressure manual adjustment valve 4 and the instrument air circuit 10. The negative pressure normally open valve 7 is installed on another pipeline connecting the air source 13 and the instrument air circuit 10, located between the negative pressure manual adjustment valve 6 and the instrument air circuit 10. These two valves are always open during normal system operation. When the positive pressure manual adjustment valve 4 or the negative pressure manual adjustment valve 6 needs adjustment or maintenance, the positive pressure normally open valve 3 and the negative pressure normally open valve 7 can maintain the basic passage of the pipeline, avoiding the risk of short-term blockage caused by airflow interruption, while also reducing pressure fluctuations during valve switching and ensuring the stability of the signal collected by the differential pressure sensor 1.

[0027] This application can be used in the field of pipeline flow measurement, or in other fields applicable to this application.

[0028] In another embodiment: a composite anti-clogging system for flow measurement, which is applied to the field of pipeline flow measurement;

[0029] In another aspect of this embodiment, the normally closed positive pressure valve 2, normally closed negative pressure valve 9, normally open positive pressure valve 3, and normally open negative pressure valve 7 all employ solenoid valves. These valves have a fast response speed, with the time from receiving the control signal to completing the opening and closing action not exceeding 0.5 seconds, enabling them to quickly respond to the commands of the control module 12. The control signal for the solenoid valve is transmitted by the control module 12 through the control circuit 8. When the control module 12 issues an opening command, the solenoid valve coil is energized to generate a magnetic field, driving the valve core to move and thus opening the valve. When the command stops, the coil is de-energized, the valve core resets under the action of the spring force, and the valve closes, achieving automated control without manual intervention.

[0030] Operating Mode 1: Under normal operating conditions, continuous purging is performed using low-pressure airflow. The normally closed positive pressure valve 2 and the normally closed negative pressure valve 9 are closed. The positive and negative pressure signals from the flowmeter 5 are sent to the high-pressure and low-pressure sides of the differential pressure sensor 1, respectively. The air source 13 is connected to the positive and negative pressure ends of the flowmeter 5. By manually adjusting the positive pressure manual valve 4 and the negative pressure manual valve 6, a suitable airflow is ensured to enter the flowmeter 5, preventing blockage without affecting the differential pressure signal. In this operating state, the positive pressure manual valve 4 and the negative pressure manual valve 6 simultaneously function as pressure reducing and stabilizing valves, reducing the air source pressure from above 3MPa to below 100Kpa. This ensures that the amount of gas blown into the flowmeter 5 does not affect its normal measurement and also provides high-pressure isolation for the flowmeter 5.

[0031] Operating Mode 2: When the control module 12 detects a potential blockage in the flow meter 5 or the instrument air path for delivering pressure, it automatically enters Operating Mode 2; alternatively, it can be manually entered by the operator. Upon entry, the control module 12 checks the communication status and the opening / closing status of each solenoid valve to ensure they are correct, and also checks for changes in pipeline load. If the pipeline load remains unchanged, it sends a pressurization command to the air source 13 and prepares an analog input to the differential pressure sensor 1 to prevent the differential pressure sensor 1 from outputting incorrect signals due to fluctuations in the air path switching, thus affecting the operation of the host computer 14. This analog input can be derived from historical data segments of the same differential pressure sensor 1 with fluctuations not exceeding 5%, or from a backup differential pressure sensor 1 operating under the same conditions.

[0032] With the differential pressure sensor 1 maintaining a signal, the control module 12 opens the positive pressure normally closed valve 2 and the negative pressure normally closed valve 9, cutting off the gas path between the flow meter 5 and the differential pressure sensor 1. Simultaneously, the positive pressure normally open valve 3 and the negative pressure normally open valve 7 are closed, connecting the gas source 13 to the instrument gas path on the positive and negative pressure sides of the flow meter. Once the gas source 13 is pressurized, it can be released. The high-pressure gas will quickly fill the instrument gas path and then be depressurized from the pressure tap of the flow meter 5 into the pipeline, simultaneously carrying away various impurities and dust that may be clogging the flow meter 5 and the instrument gas path. Since the flow rates of the positive pressure manual valve 4 and the negative pressure manual valve 6 are much smaller than those of the positive pressure normally open valve 3 and the negative pressure normally open valve 7, no specific requirements are placed on the opening and closing of the positive pressure manual valve 4 and the negative pressure manual valve 6.

[0033] Positive pressure normally closed valve 2, negative pressure normally closed valve 9, positive pressure normally open valve 3, negative pressure normally open valve 7, positive pressure manually adjustable valve 4, and negative pressure manually adjustable valve 6 can be designed in combination for use as a valve group, or they can be arranged and controlled independently.

[0034] The basis for detecting changes in pipeline load can be the opening and closing angle of the pipeline damper, or changes in power generation load, electricity consumption, or energy consumption data.

[0035] When the pipeline load change is less than ±5%, and the output signal of differential pressure sensor 1 continuously shows a unidirectional changing trend with a total change trend greater than twice the pipeline load change, it is considered that there is a possibility of blockage in flow meter 5 or the instrument passage, and the system will automatically switch to working mode 2. If working mode 2 is automatically switched to three times in a day, it indicates that the blockage point may be located in the instrument passage, and control module 12 will send a signal to host computer 14 to remind the user to manually check for leaks in the instrument passage.

[0036] The accompanying drawings in this application are for illustrative purposes only. The dimensions and shapes of the components shown are not actual limitations but are merely schematic representations. In actual implementation, the components can be reasonably configured and adjusted according to specific needs and actual conditions.

[0037] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A composite anti-clogging system for flow measurement, characterized in that, include: Three-valve manifold (11), one side of which is sealed to the differential pressure sensor (1). The flow meter (5) is located on one side of the three-valve group (11). Its positive pressure end is sealed and connected to one end of the three-valve group (11) through the instrument air passage (10) equipped with a positive pressure normally closed valve (2), and its negative pressure end is sealed and connected to the other end of the three-valve group (11) through the instrument air passage (10) equipped with a negative pressure normally closed valve (9). The control module (12) is located on one side of the instrument air circuit (10). The positive pressure normally closed valve (2) and the negative pressure normally closed valve (9) are connected to the control module (12) through the control circuit (8). The host computer (14) is connected to the control module (12) through the control loop (8); Two sets of air sources (13) are connected to the positive pressure end of the flow meter (5) through a pipeline equipped with a positive pressure manual adjustment valve (4), and the other set is connected to the negative pressure end of the flow meter (5) through a pipeline equipped with a negative pressure manual adjustment valve (6). Among them, the gas source (13) outputs low-pressure airflow to purge the flow meter (5) and instrument air path (10) through the positive pressure manual adjustment valve (4) and the negative pressure manual adjustment valve (6) to prevent blockage. The differential pressure signal collected by the differential pressure sensor (1) is transmitted to the host computer (14) through the control module (12).

2. The composite anti-clogging system for flow measurement according to claim 1, characterized in that, It also includes a positive pressure normally open valve (3) and a negative pressure normally open valve (7). The positive pressure normally open valve (3) is located in the pipeline between one set of gas sources (13) and the instrument gas line (10), and the negative pressure normally open valve (7) is located in the pipeline between the other set of gas sources (13) and the instrument gas line (10).

3. A composite anti-clogging system for flow measurement according to claim 1, characterized in that, The normally closed positive pressure valve (2), normally closed negative pressure valve (9), normally open positive pressure valve (3), and normally open negative pressure valve (7) are all solenoid valves.

4. A composite anti-clogging system for flow measurement according to claim 1, characterized in that, The control module (12) can detect changes in pipeline load and the output signal of differential pressure sensor (1). When the change in pipeline load is less than ±5%, and the duration of the continuous unidirectional change trend of the output signal of differential pressure sensor (1) exceeds the preset threshold and the change amplitude is greater than twice the change amplitude of pipeline load, the control module (12) determines that there is a risk of blockage in the system and starts the cleaning mode.

5. A composite anti-clogging system for flow measurement according to claim 1, characterized in that, The positive pressure normally closed valve (2), negative pressure normally closed valve (9), positive pressure normally open valve (3), negative pressure normally open valve (7), positive pressure manually adjustable valve (4), and negative pressure manually adjustable valve (6) can be combined into an integral valve group for installation, or arranged and controlled independently according to the installation space and maintenance requirements.

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