A pulse type anti-clogging back purge air velocity measurement system

Abstract

This utility model discloses a pulse-type anti-clogging backflush air velocity measurement system, including a differential pressure tapping unit, a differential pressure transmitter, a control cabinet unit, and a pulse anti-clogging backflush unit. The differential pressure tapping unit is installed inside the fluid pipeline to be measured, used to collect the positive and negative pressures of the fluid in the pipeline, and transmit the differential pressure signal through the positive and negative pressure pipelines. The differential pressure transmitter is used to convert the received differential pressure signal into a current signal. The control cabinet unit is used to receive the standard current signal, calculate and display the real-time flow velocity, and transmit the signal to the power plant's central control room. The pulse anti-clogging backflush unit is connected to the positive and negative pressure pipelines. The pulse anti-clogging backflush unit includes at least one set of protection modules for protecting the differential pressure transmitter. Both the shut-off valve and the pulse valve are closed in the non-backflush state, forming a double closure to prevent compressed air leakage into the measurement pipeline, thus preventing measurement data errors.

Description

Technical Field

[0001] This utility model relates to the field of wind speed measurement technology, specifically a pulse-type anti-blocking back-blowing wind speed measurement system. Background Technology

[0002] In the production process of thermal power plants, the uniform and stable delivery of pulverized coal is crucial to the boiler combustion efficiency and operational safety. The airflow velocity (i.e., primary air velocity) in the pulverized coal pipe is a key parameter for controlling the pulverized coal delivery volume and ensuring uniform gas-pulverized coal mixing. Therefore, long-term, accurate, and reliable online measurement of the pulverized coal pipe velocity is of great significance.

[0003] Currently, commonly used industrial wind speed measurement methods include using Pitot tubes and thermal anemometers. However, the pressure measuring holes of Pitot tubes and the probe surfaces of thermal anemometers are easily clogged and adhered by coal dust particles in high dust concentration environments such as coal pulverizer pipes in thermal power plants, resulting in a serious decrease in measurement accuracy and requiring frequent maintenance. Based on this, this utility model proposes a pulse-type anti-clogging back-blowing wind speed measurement system that can solve the above problems. Utility Model Content

[0004] The purpose of this invention is to provide a pulse-type anti-blocking backflushing wind speed measurement system to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a pulse-type anti-clogging backflushing wind speed measurement system, comprising:

[0006] The differential pressure tapping unit is installed inside the pipeline containing the fluid being measured. It is used to acquire the positive and negative pressures of the fluid within the pipeline and transmit the differential pressure signal through positive and negative pressure pipelines.

[0007] A differential pressure transmitter is used to convert a received differential pressure signal into a current signal.

[0008] The control cabinet unit is used to receive standard current signals, calculate and display the real-time flow rate, and transmit the signal to the power plant's central control room.

[0009] The pulse anti-clogging backflush unit is connected to the positive pressure pipeline and the negative pressure pipeline and is controlled by the control cabinet unit. It is used to perform timed alternating pulse purging on the positive pressure pipeline, the negative pressure pipeline and the differential pressure tapping unit.

[0010] The pulse anti-blockage backflush unit includes at least one set of protection modules for protecting the differential pressure transmitter. The protection modules are activated during backflush to isolate and release backflush pressure.

[0011] As a preferred technical solution, the pulse anti-blocking backflush unit includes a main air source valve, which is installed on a main air source pipe. The main air source pipe is connected to two sets of branch air source pipes, which are respectively connected to the positive pressure pipeline and the negative pressure pipeline. A blocking valve and a pulse valve are respectively installed on the two sets of branch air source pipes.

[0012] As a preferred technical solution, a pressure reducing filter is installed in the gas source main pipe after the gas source main valve. The pressure reducing filter is used to adjust the backflush pressure and filter water vapor and impurities in the gas.

[0013] As a preferred technical solution, the protection module includes an isolation valve and a secondary protection valve respectively installed on the positive pressure pipeline and the negative pressure pipeline.

[0014] As a preferred technical solution, the secondary protection valve is a three-way valve with an exhaust port that opens to the atmospheric environment.

[0015] As a preferred technical solution, the control cabinet unit has a signal locking module, which is used to lock the output value of the current signal during backflushing.

[0016] Compared with the prior art, the beneficial effects of this utility model are:

[0017] Both the shut-off valve and the pulse valve are closed in the non-backflushing state, forming a double closure to prevent compressed air from leaking into the measuring pipeline and causing measurement data errors. The pulse anti-clogging backflushing unit adopts a timed alternating pulse purging method, with instantaneous high-pressure pulse purging, which significantly improves the ash removal effect compared to continuous purging.

[0018] The isolation valve closes during backflush, effectively blocking the backflush pressure from directly impacting the differential pressure transmitter. Even if there is a leak in the isolation valve, the leaked high-pressure airflow will be safely discharged into the atmosphere through the exhaust port of the secondary protection valve and will not affect the differential pressure transmitter, thus providing double protection for the differential pressure transmitter and preventing damage to the transmitter.

[0019] The control cabinet unit's display screen shows wind speed parameters and can automatically control the backflushing frequency and cycle. The signal is automatically maintained during backflushing, ensuring the long-term stable, accurate, and reliable operation of the entire measurement system. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure;

[0021] In the diagram: 1. Differential pressure tapping unit; 2. Positive pressure pipeline; 3. Negative pressure pipeline; 4. Differential pressure transmitter; 5. Control cabinet unit; 6. Main air supply valve; 7. Pressure reducing filter; 8. Shut-off valve; 9. Pulse valve; 10. Isolation valve; 11. Secondary protection valve. Detailed Implementation

[0022] The following is a detailed description of a pulse-type anti-blocking backflushing wind speed measurement system according to an embodiment of the present disclosure, with reference to the accompanying drawings. To make the objectives, technical solutions, and advantages of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present disclosure.

[0023] Therefore, the following detailed description of embodiments of the present disclosure provided in conjunction with the accompanying drawings is not intended to limit the scope of the claimed disclosure, but merely to illustrate selected embodiments of the disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of the present disclosure without inventive effort are within the scope of protection of the present disclosure.

[0024] See Figure 1 A pulse-type anti-clogging backflush velocity measuring device is provided, comprising a differential pressure tapping unit 1, a differential pressure transmitter 4, a control cabinet unit 5, and a pulse anti-clogging backflush unit.

[0025] Differential pressure tapping unit 1 is installed inside the pipeline of the fluid to be measured. Differential pressure tapping unit 1 collects the positive and negative pressure of the fluid in the pipeline by means of back-to-back differential pressure principle, and transmits the differential pressure signal through positive pressure pipeline 2 and negative pressure pipeline 3. Differential pressure tapping unit 1 has positive pressure tapping and negative pressure tapping points. Positive pressure pipeline 2 and negative pressure pipeline 3 lead out the collected pressure.

[0026] Differential pressure transmitter 4 is connected to positive pressure line 2 and negative pressure line. Differential pressure transmitter 4 is used to convert the received differential pressure signal into a current signal. The current signal is 4-20mA, which has strong anti-interference ability and is easy to transmit over long distances.

[0027] The control cabinet unit 5 is composed of a programmable logic controller (PLC) as its core. The control cabinet unit 5 is used to receive the 4-20mA current signal from the differential pressure transmitter 4, calculate and display the real-time flow rate. The real-time flow rate calculation result can be displayed on the display screen of the control cabinet unit 5 and the signal can be transmitted to the power plant central control room.

[0028] The pulse anti-clogging backflushing unit is connected to the positive pressure pipeline 2 and the negative pressure pipeline 3 and is controlled by the control cabinet unit. It is used to perform timed alternating pulse purging on the positive pressure pipeline 2, the negative pressure pipeline 3 and the differential pressure tapping unit 1. The control cabinet unit 5 has a timer and preset control logic. According to the preset time cycle, such as every 1-2 hours, it controls the pulse anti-clogging backflushing unit to start alternating backflushing and instantaneous high-pressure pulse purging. Compared with continuous purging, the dust removal effect is significantly improved.

[0029] The pulse anti-clogging backflush unit includes a main air supply valve 6, which is installed on a main air supply pipe (instrument air supply 0.4-1.0MPa). The main air supply pipe is connected to two sets of branch air supply pipes, which are respectively connected to the positive pressure pipe 2 and the negative pressure pipe. A shut-off valve 8 and a pulse valve 9 are installed on the two sets of branch air supply pipes respectively.

[0030] The shut-off valve 8 is a solenoid valve located at the front end of the pulse valve 9. The pulse valve 9 is used to generate short and powerful air pulses. Both the shut-off valve 8 and the pulse valve 9 are closed in the non-backflush state, forming a double closure to prevent compressed air from leaking into the measuring pipeline and causing measurement data errors.

[0031] A pressure reducing filter 7 is installed after the main gas valve 6 in the main gas supply pipe. The pressure reducing filter 7 is used to regulate the backflush pressure and filter water vapor and impurities in the gas to ensure the cleanliness of the purge gas.

[0032] The pulse anti-clogging backflush unit also includes a protection module. The protection module is used to protect the differential pressure transmitter 4. The protection module is activated during backflush to isolate and release backflush pressure. The protection module includes an isolation valve 10 and a secondary protection valve 11 installed on the positive pressure line 2 and the negative pressure line 3, respectively. The isolation valve 10 is closed during backflush to effectively block the backflush pressure from directly impacting the differential pressure transmitter 4. The secondary protection valve 11 is a three-way valve with an exhaust port that opens to the atmosphere. During backflush, even if there is a leak in the isolation valve 10, the leaked high-pressure airflow will be safely discharged into the atmosphere through the exhaust port of the secondary protection valve 11 and will not act on the differential pressure transmitter 4, thus forming a double protection for the differential pressure transmitter 4 and preventing damage to the transmitter.

[0033] The control cabinet unit 5 has a signal locking module, which is used to lock the output value of the current signal during backflushing. The signal locking module keeps the control cabinet unit 5 at the measurement value at the last moment before backflushing starts, and resumes the transmission of the real-time flow rate signal after backflushing ends.

[0034] Working principle: During non-backflushing periods, the pressure is collected by the differential pressure tapping unit 1 and converted into a 4-20mA current signal by the differential pressure transmitter 4. The control cabinet unit calculates and displays the real-time flow rate and transmits the signal remotely. After the timing of the control cabinet unit 5 reaches the preset cycle, the control pulse anti-blocking backflushing unit is activated, the control isolation valve 10 is closed and the secondary protection valve 11 is opened to provide transmitter protection for backflushing. The blocking valve 8 is opened and the pulse valve 9 is driven to generate periodic high-pressure air pulses to backflush and clean the positive and negative pressure pipelines 3 and the pressure tapping unit. After the backflushing is completed, the blocking valve 8 and the pulse valve 9 are closed, then the isolation valve 10 is closed, the secondary protection valve 11 is closed, and the measurement state is restored.

[0035] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A pulse-type anti-clogging backflush velocity measurement system, characterized in that, include: The differential pressure tapping unit is installed inside the pipeline containing the fluid being measured. It is used to acquire the positive and negative pressures of the fluid within the pipeline and transmit the differential pressure signal through positive and negative pressure pipelines. A differential pressure transmitter is used to convert a received differential pressure signal into a current signal. The control cabinet unit is used to receive standard current signals, calculate and display the real-time flow rate, and transmit the signal to the power plant's central control room. The pulse anti-clogging backflush unit is connected to the positive pressure pipeline and the negative pressure pipeline and is controlled by the control cabinet unit. It is used to perform timed alternating pulse purging on the positive pressure pipeline, the negative pressure pipeline and the differential pressure tapping unit. The pulse anti-blockage backflush unit includes at least one set of protection modules for protecting the differential pressure transmitter. The protection modules are activated during backflush to isolate and release backflush pressure.

2. The pulse-type anti-clogging backflush wind speed measurement system according to claim 1, characterized in that, The pulse anti-clogging backflush unit includes a main air source valve, which is installed on a main air source pipe. The main air source pipe is connected to two sets of branch air source pipes, which are respectively connected to the positive pressure pipeline and the negative pressure pipeline. A shut-off valve and a pulse valve are respectively installed on the two sets of branch air source pipes.

3. The pulse-type anti-clogging back-blowing wind speed measurement system according to claim 2, characterized in that, A pressure reducing filter is installed behind the main gas valve on the main gas supply pipe. The pressure reducing filter is used to adjust the backflush pressure and filter water vapor and impurities in the gas.

4. The pulse-type anti-clogging back-blowing wind speed measurement system according to claim 1, characterized in that, The protection module includes an isolation valve and a secondary protection valve installed on the positive pressure pipeline and the negative pressure pipeline, respectively.

5. The pulse-type anti-clogging back-blowing wind speed measurement system according to claim 4, characterized in that, The secondary protection valve is a three-way valve with an exhaust port that opens to the atmospheric environment.

6. The pulse-type anti-clogging back-blowing wind speed measurement system according to claim 1, characterized in that, The control cabinet unit has a signal locking module, which is used to lock the output value of the current signal during backflushing.

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