阅读说明：本技术 一种烟气流速检测系统及其使用方法 (Flue gas flow velocity detection system and application method thereof ) 是由 邢亮 王永刚 李宝旗 刘宝康 周会 于 2020-12-02 设计创作，主要内容包括：本发明涉及一种烟气流速监测系统及其使用方法,该系统包括静压传感器、动压传感器以及设置在烟道内的密封的取压管道,所述取压管道靠近烟道中心的一端为锥形部,取压管道内设有横向的隔板,隔板将取压管道分隔成上方的静压腔和下方的动压腔,锥形部的上方开有与静压腔连通的静压进气口,锥形部的下方开有与动压腔连通的动压进气口,所述动压腔通过管路与动压传感器连通,所述静压腔通过管路与静压传感器连通,本发明的一种烟气流速监测系统及其使用方法,仪器采用皮托管差压法测量烟气流速,并可对烟气压力、温度直接进行测量,使得测量精度和准确性大大提高,而且降低了使用成本和维护工作量,特别适合用于在线实时测量烟气参数。(The invention relates to a flue gas velocity monitoring system and a using method thereof, the system comprises a static pressure sensor, a dynamic pressure sensor and a sealed pressure taking pipeline arranged in a flue, one end of the pressure taking pipeline close to the center of the flue is a conical part, a transverse partition plate is arranged in the pressure taking pipeline, the pressure taking pipeline is divided into an upper static pressure cavity and a lower dynamic pressure cavity by the partition plate, a static pressure air inlet communicated with the static pressure cavity is arranged above the conical part, a dynamic pressure air inlet communicated with the dynamic pressure cavity is arranged below the conical part, the dynamic pressure cavity is communicated with the dynamic pressure sensor by a pipeline, and the static pressure cavity is communicated with the static pressure sensor by a pipeline. And the use cost and the maintenance workload are reduced, and the device is particularly suitable for online real-time measurement of the flue gas parameters.)

1. A flue gas flow rate monitoring system is characterized in that: including static pressure sensor (6), dynamic pressure sensor (7) and set up sealed pressure pipeline (12) of getting in the flue, the one end that gets pressure pipeline (12) and be close to the flue center is the toper portion, gets to be equipped with horizontal baffle (13) in pressure pipeline (12), and the baffle will get pressure pipeline (12) and separate into the static pressure chamber of top and the pressure chamber that moves of below, and open the top of toper portion has static pressure air inlet (14) with static pressure chamber intercommunication, and open the below of toper portion has dynamic pressure air inlet (15) with dynamic pressure chamber intercommunication, it communicates with dynamic pressure sensor (7) through pipeline to move the pressure chamber, the static pressure chamber passes through pipeline and static pressure sensor (6) intercommunication.

2. A flue gas flow rate monitoring system according to claim 1, wherein: the back flushing protection electromagnetic valve A (3) is arranged on a pipeline through which the dynamic pressure cavity is communicated with the dynamic pressure sensor (7), the back flushing protection electromagnetic valve B (4) is arranged on a pipeline through which the static pressure cavity is communicated with the static pressure sensor (6), the back flushing protection electromagnetic valve A (3) and the back flushing protection electromagnetic valve B (4) are both one-inlet two-outlet type three-way electromagnetic valves, the static pressure sensor (6) is communicated with a normally open outlet of the back flushing protection electromagnetic valve B (4), the dynamic pressure sensor (7) is communicated with the normally open outlet of the back flushing protection electromagnetic valve A (3), and the normally closed outlet of the back flushing protection electromagnetic valve A (3) and the normally closed outlet of the back flushing protection electromagnetic valve B (4) are communicated with a back flushing air source through pipelines respectively.

3. A flue gas flow rate monitoring system according to claim 2, wherein: and a back-blowing electromagnetic valve A (1) is arranged on a pipeline communicated with the back-blowing protection electromagnetic valve A (3) and the air source, and a back-blowing electromagnetic valve B (2) is arranged on a pipeline communicated with the back-blowing protection electromagnetic valve B (4) and the air source.

4. A flue gas flow rate monitoring system according to claim 1, wherein: and the static pressure sensor (6) and the dynamic pressure sensor (7) are both arranged in the shell.

5. A flue gas flow rate monitoring system according to claim 1, wherein: and a temperature sensor (16) is arranged on the pressure taking pipeline (12).

6. A flue gas flow rate monitoring system according to claim 1, wherein: the pressure taking pipeline (12) is a circular pipe.

7. A use method of a flue gas flow rate monitoring system is characterized by comprising the following steps:

a. horizontally inserting one end of a conical part of the pressure taking pipeline (12) into the flue, and enabling the dynamic pressure air inlet (15) to face downwards and the static pressure air inlet (14) to face upwards;

b. the smoke in the flue flows upwards, and the smoke enters the dynamic pressure cavity through the dynamic pressure air inlet (15) to increase the pressure in the dynamic pressure cavity; the smoke flowing through the conical part flows upwards through the static pressure air inlet (14) to reduce the pressure in the static pressure cavity;

c. the pressure intensity in the dynamic pressure cavity is detected through a dynamic pressure sensor (7), the pressure intensity in the static pressure cavity is detected through a static pressure sensor (6), and therefore the flow velocity of the flue gas is obtained through calculation;

d. starting a back-blowing protection electromagnetic valve A (3) and a back-blowing protection electromagnetic valve B (4), closing pipelines leading to a dynamic pressure sensor (7) and a static pressure sensor (6), and communicating pipelines leading to a back-blowing electromagnetic valve A (1) and a back-blowing electromagnetic valve B (2);

e. then opening a back-blowing electromagnetic valve A (1) and a back-blowing electromagnetic valve B (2) to enable a back-blowing air source to be communicated with the dynamic pressure cavity and the static pressure cavity;

f. the movable pressure cavity and the static pressure cavity are subjected to back blowing through a back blowing air source, and the inner wall of the pressure measuring pipeline is subjected to ash removal, so that the anti-blocking effect is achieved.

Technical Field

The invention relates to the technical field of flue gas monitoring, in particular to a flue gas flow velocity monitoring system and a using method thereof.

Background

Thermal power generation is consuming a large amount of non-renewable resources on the earth while providing clean energy for human beings, and is also continuously generating a large amount of byproducts such as waste gas, waste water and waste residue, which increasingly pollutes the earth environment and finally brings disasters to human production and life.

Today, with increasing environmental pollution, various methods are being sought to control or reduce the pollution, including pretreatment of these solid emissions, on-line measurement of flue gas emissions (CEMS). The CEMS system monitors parameters such as SO2, NOx, smoke dust, and the like in real time, and also monitors parameters such as flow rate, pressure, temperature, and the like of flue gas, SO as to adjust the combustion condition and the flue gas emission condition of the boiler in time.

The high-temperature flue gas generally refers to gas generated in coal-fired power generation engineering in the thermal power industry, is used as a special medium, the general temperature range is 50-120 ℃, and can reach 160 ℃ under special conditions, in addition, dust and acidic substances such as SO2, NOX and the like generally exist in the flue gas, and how to overcome the high temperature, high dust and acidic substances to ensure the on-line measurement of the flow rate of the flue gas is a very difficult problem, and under the condition, the necessary detection accuracy is ensured, and the reaction speed is high; the installation and calibration are easy; protection requirements such as dust prevention, splash prevention and corrosion prevention; the automation degree is high, and the maintenance workload is low. In order to solve these problems, a reliable measuring instrument is required to accurately measure the flow rate, pressure and temperature of the flue gas for the severe measurement of high temperature, high dust, high humidity and high corrosion in the flue.

The concentration and the total amount of pollutants discharged from a fixed pollution source are controlled in China, and the flow speed (flow) of discharged flue gas is an important parameter for determining the total amount of the pollutants.

The currently generally adopted methods for flue gas flow rate are divided into two main categories:

(1) and (3) calculation method: such as steam flow method, chemical equilibrium calculation method for fuel combustion and calculation method for smoke volume flow rate by induced draft fan hour power.

(2) Measurement method: such as: pitot tube methods, ultrasonic methods, sonic methods, thermal equilibrium methods, target flow meter methods, light scintillation methods, infrared methods, and the like.

The flue for mounting the CEMS of the flue gas of the fixed pollution source in China hardly meets the requirement of flow field stability, the flow velocity is not uniformly distributed in the flue, and the difficulty in measuring the flow velocity of the flue gas is caused when the flow velocity is less than 10m/s (particularly when the flow velocity is less than 5 m/s).

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a flue gas flow velocity monitoring system and a using method thereof.

The invention is realized by the following technical scheme, and provides a flue gas flow velocity monitoring system and a using method thereof, wherein the flue gas flow velocity monitoring system comprises a static pressure sensor, a dynamic pressure sensor and a sealed pressure taking pipeline arranged in a flue, one end of the pressure taking pipeline close to the center of the flue is a conical part, a transverse partition plate is arranged in the pressure taking pipeline, the pressure taking pipeline is divided into an upper static pressure cavity and a lower dynamic pressure cavity by the partition plate, a static pressure air inlet communicated with the static pressure cavity is formed above the conical part, a dynamic pressure air inlet communicated with the dynamic pressure cavity is formed below the conical part, the dynamic pressure cavity is communicated with the dynamic pressure sensor through a pipeline, and the static pressure cavity is communicated with the static pressure sensor through a pipeline.

The pressure measuring pipeline in the scheme adopts a Pitot tube method measuring principle, and according to Bernoulli equation, the energy in the fluid flowing process comprises potential energy, kinetic energy and static pressure energy; for gas flow, the change of potential energy is usually ignored, and kinetic energy and static pressure energy can be mutually converted under certain conditions; get the total energy and the static pressure energy that the dynamic pressure air inlet and the static pressure air inlet of pressing the pipeline represented gas respectively, the difference between the two is the dynamic pressure energy, the dynamic pressure energy is directly proportional with the square of gas velocity of flow, through communicateing dynamic pressure sensor and static pressure sensor respectively with dynamic pressure air inlet and static pressure air inlet, thereby measure the velocity of flow of gas in the flue, because dynamic pressure air inlet and static pressure air inlet set up on the toper portion, when the flue gas flows through the toper portion, the flue gas flows along the toper portion surface, can increase the peripheral flue gas velocity of flow of toper portion, thereby increase the flue gas velocity of flow through static pressure air inlet department, thereby the flow curve through the flue gas makes the measurement more accurate, even when the flow is less, also can realize the accurate.

Preferably, a back-blowing protection electromagnetic valve A is arranged on a pipeline through which the dynamic pressure cavity is communicated with the dynamic pressure sensor, a back-blowing protection electromagnetic valve B is arranged on a pipeline through which the static pressure cavity is communicated with the static pressure sensor, the back-blowing protection electromagnetic valve A and the back-blowing protection electromagnetic valve B are both one-inlet two-outlet three-way electromagnetic valves, the static pressure sensor is communicated with a normally open outlet of the back-blowing protection electromagnetic valve B, the dynamic pressure sensor is communicated with the normally open outlet of the back-blowing protection electromagnetic valve A, and the normally closed outlet of the back-blowing protection electromagnetic valve A and the normally closed outlet of the back-blowing protection electromagnetic valve B are respectively communicated with a.

The dynamic pressure chamber and the dynamic pressure sensor in this scheme are always on, and the static pressure chamber and the static pressure sensor are always on, and when needs carry out the blowback, blowback protection solenoid valve A and blowback protection solenoid valve B switch over, make blowback air supply intercommunication dynamic pressure chamber and static pressure chamber, carry out the blowback through blowback air supply to dynamic pressure chamber and static pressure chamber, to getting the automatic real-time deashing of whole wall of pressing the pipeline, reach and prevent stifled purpose.

Preferably, a back-blowing electromagnetic valve A is arranged on a pipeline for communicating the back-blowing protection electromagnetic valve A with an air source, and a back-blowing electromagnetic valve B is arranged on a pipeline for communicating the back-blowing protection electromagnetic valve B with the air source. Through the blowback solenoid valve A and the blowback solenoid valve B that set up in this scheme, when carrying out the blowback, switch back protection solenoid valve A and blowback protection solenoid valve B earlier, then open blowback solenoid valve A and blowback solenoid valve B again and carry out the blowback, prevent that blowback protection solenoid valve A and blowback protection solenoid valve B from switching in the twinkling of an eye blowback gas gets into dynamic pressure sensor or static pressure sensor.

Preferably, the static pressure sensor and the dynamic pressure sensor are both arranged in the shell. The casing that sets up in this scheme plays the guard action to static pressure sensor and dynamic pressure sensor.

And as optimization, a temperature sensor is arranged on the pressure measuring pipeline. The temperature sensor in the scheme is used for detecting the temperature of the flue gas.

Preferably, the pressure measuring pipeline is a round pipe. Get in this scheme and press the pipeline to be the pipe, make the one end that gets to press the pipeline to be close to the flue center be conical, can take a sample better.

A use method of a flue gas flow rate monitoring system comprises the following steps:

a. horizontally inserting one end of a conical part of the pressure taking pipeline into the flue, and enabling the dynamic pressure air inlet to face downwards and the static pressure air inlet to face upwards;

b. the smoke in the flue flows upwards, and enters the dynamic pressure cavity through the dynamic pressure air inlet, so that the pressure in the dynamic pressure cavity is increased; the smoke flowing through the conical part flows upwards through the static pressure air inlet, so that the pressure in the static pressure cavity is reduced;

c. the pressure intensity in the dynamic pressure cavity is detected through the dynamic pressure sensor, the pressure intensity in the static pressure cavity is detected through the static pressure sensor, and therefore the flue gas flow velocity is obtained through calculation;

d. starting a back-blowing protection electromagnetic valve A and a back-blowing protection electromagnetic valve B, closing pipelines leading to a dynamic pressure sensor and a static pressure sensor, and communicating pipelines leading to the back-blowing electromagnetic valve A and the back-blowing electromagnetic valve B;

e. then opening a back-blowing electromagnetic valve A and a back-blowing electromagnetic valve B to enable a back-blowing air source to be communicated with the dynamic pressure cavity and the static pressure cavity;

f. the movable pressure cavity and the static pressure cavity are subjected to back blowing through a back blowing air source, and the inner wall of the pressure measuring pipeline is subjected to ash removal, so that the anti-blocking effect is achieved.

The invention has the beneficial effects that: according to the flue gas flow velocity monitoring system and the using method thereof, the instrument measures the flue gas flow velocity by adopting a pitot tube differential pressure method, and can directly measure the pressure and the temperature of the flue gas, so that the measurement precision and the accuracy are greatly improved, the use cost and the maintenance workload are reduced, and the system is particularly suitable for measuring the flue gas parameters on line in real time and meets the national environmental protection industry standard.

The instrument has a simple structure, is convenient to install, integrates a plurality of measurement technologies, and can realize long-term stable and high-performance online measurement of parameters such as flue gas flow velocity and the like; more selectable modules and parameters can greatly enhance the measurement range of the flue gas parameter monitor.

Drawings

FIG. 1 is a schematic diagram of the structure of the present invention;

FIG. 2 is a schematic structural view of the present invention without a pressure tapping pipe;

shown in the figure:

1. the device comprises back-blowing electromagnetic valves A, 2, back-blowing electromagnetic valves B, 3, back-blowing protection electromagnetic valves A, 4, back-blowing protection electromagnetic valves B, 5, a touch operation panel, 6, a static pressure sensor, 7, a dynamic pressure sensor, 8, a temperature sensor chip, 9, an analog output wiring terminal, 10, a shell, 11, a rainproof connector lug, 12, a pressure tapping pipeline, 13, a partition plate, 14, a static pressure air inlet, 15, a dynamic pressure air inlet, 16 and a temperature sensor.

Detailed Description

In order to clearly illustrate the technical features of the present solution, the present solution is explained below by way of specific embodiments.

As shown in fig. 1-2, the flue gas flow velocity monitoring system and the using method thereof of the present invention include a static pressure sensor 9, a dynamic pressure sensor 10, and a sealed pressure tapping pipe 1 disposed in a flue, wherein one end of the pressure tapping pipe 1 is inserted into the flue, the pressure tapping pipe 1 is a circular pipe, one end of the pressure tapping pipe 1 away from the center of the flue is sealed by a sealing plate, one end of the pressure tapping pipe 1 close to the center of the flue is a tapered portion, and the tapered portion is conical.

Be equipped with horizontal baffle 2 in the pressure pipeline 1, the baffle will be got pressure pipeline 1 and is separated into the quiet pressure chamber in top and the dynamic pressure chamber in below, and quiet pressure chamber is the same with dynamic pressure cavity volume.

The wall thickness of the conical part is the same as that of the pressure taking pipeline 1, a static pressure air inlet 3 communicated with the static pressure cavity is formed above the conical part, a dynamic pressure air inlet 4 communicated with the dynamic pressure cavity is formed below the conical part, and the static pressure air inlet 3 and the dynamic pressure air inlet 4 are both oval.

The dynamic pressure cavity is communicated with a dynamic pressure sensor 10 through a pipeline, the static pressure cavity is communicated with a static pressure sensor 9 through a pipeline, and the pipelines of the dynamic pressure cavity and the static pressure cavity are communicated on the sealing plate.

Get and be equipped with temperature sensor 11 on the pressure pipeline 1, temperature sensor 11 installs in the one end that pressure pipeline 1 is close to the toper portion, and temperature sensor 11 installs in the pressure pipeline 1 outside to be convenient for detect flue gas temperature.

A back-blowing protection electromagnetic valve A7 is arranged on a pipeline through which the dynamic pressure cavity is communicated with the dynamic pressure sensor 10, a back-blowing protection electromagnetic valve B8 is arranged on a pipeline through which the static pressure cavity is communicated with the static pressure sensor 9, the back-blowing protection electromagnetic valve A7 and the back-blowing protection electromagnetic valve B8 are both one-in two-out three-way electromagnetic valves, the static pressure sensor 9 is communicated with a normally open outlet of the back-blowing protection electromagnetic valve B8, the dynamic pressure sensor 10 is communicated with a normally open outlet of the back-blowing protection electromagnetic valve A7, and a normally closed outlet of the back-blowing protection electromagnetic valve A7 and a normally closed outlet of the back-blowing protection electromagnetic valve B8 are respectively communicated with.

The back-blowing gas requires the use of compressed air for instruments, nitrogen and other oil-free, water-free and dust-free gases. The back-blowing air interface is a phi 8 quick connector. The back-blowing pressure range is as follows: 0.3-0.5 mpa.

The back flushing time is about 30 seconds, the interval time can be automatically controlled, the standard back flushing interval time is 1 hour, and the specific time interval can be customized according to the requirements of customers.

Move pressure chamber and dynamic pressure sensor normal open, quiet pressure chamber and static pressure sensor normal open, when needs carry out the blowback, blowback protection solenoid valve A and blowback protection solenoid valve B switch over, make blowback air supply intercommunication move pressure chamber and quiet pressure chamber, carry out the blowback through blowback air supply to moving pressure chamber and static pressure chamber, to getting the automatic real-time deashing in full wall of pressing the pipeline, reach and prevent stifled purpose.

And a back-blowing electromagnetic valve A5 is arranged on a pipeline for communicating the back-blowing protection electromagnetic valve A7 with an air source, and a back-blowing electromagnetic valve B6 is arranged on a pipeline for communicating the back-blowing protection electromagnetic valve B8 with the air source. When back flushing is carried out, the back flushing protection electromagnetic valve A and the back flushing protection electromagnetic valve B are switched firstly, then the back flushing electromagnetic valve A and the back flushing electromagnetic valve B are opened for back flushing, and instant back flushing gas entering the dynamic pressure sensor or the static pressure sensor is prevented from being switched by the back flushing protection electromagnetic valve A and the back flushing protection electromagnetic valve B.

The static pressure sensor 9 and the dynamic pressure sensor 10 are both installed in the machine shell 10, the machine shell 10 is protected by composite spraying of steel spraying plastics, and a double-hasp structure is adopted, so that the machine shell is easy to install and disassemble and can be directly used in outdoor environment.

The back-blowing protection electromagnetic valve A7, the back-blowing electromagnetic valve A5, the back-blowing protection electromagnetic valve B8 and the back-blowing electromagnetic valve B6 are all installed in the machine shell 10.

A temperature sensor chip 8 is also arranged in the shell, and the temperature sensor chip 8 is electrically connected with a temperature sensor 11.

The casing 10 is provided with a touch control operation panel 5, the casing 10 is also provided with an analog output wiring terminal used for being connected with an electric wire, and the wiring terminal on the casing 10 is a rainproof wiring terminal 11.

A use method of a flue gas flow rate monitoring system comprises the following steps:

a. one end of the tapered portion of the pressure-taking pipe 12 is inserted horizontally into the flue, and the dynamic pressure inlet 15 faces downward and the static pressure inlet 14 faces upward.

b. The smoke in the flue flows upwards, and enters the dynamic pressure cavity through the dynamic pressure air inlet 15, so that the pressure in the dynamic pressure cavity is increased; the flue gas flowing through the cone portion flows upwards through the static pressure inlet 14, causing the pressure in the static pressure chamber to decrease.

c. The pressure intensity in the dynamic pressure cavity is detected through the dynamic pressure sensor 7, the pressure intensity in the static pressure cavity is detected through the static pressure sensor 6, and therefore the flue gas flow velocity is obtained through calculation.

d. And starting the back-blowing protection electromagnetic valve A3 and the back-blowing protection electromagnetic valve B4, closing the pipelines leading to the dynamic pressure sensor 7 and the static pressure sensor 6, and communicating the pipelines leading to the back-blowing electromagnetic valve A1 and the back-blowing electromagnetic valve B2.

e. And then opening a back-blowing electromagnetic valve A1 and a back-blowing electromagnetic valve B2 to enable a back-blowing air source to be communicated with the dynamic pressure cavity and the static pressure cavity.

f. The movable pressure cavity and the static pressure cavity are subjected to back blowing through a back blowing air source, and the inner wall of the pressure measuring pipeline is subjected to ash removal, so that the anti-blocking effect is achieved.

Of course, the above description is not limited to the above examples, and the undescribed technical features of the present invention can be implemented by or using the prior art, and will not be described herein again; the above embodiments and drawings are only for illustrating the technical solutions of the present invention and not for limiting the present invention, and the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that changes, modifications, additions or substitutions within the spirit and scope of the present invention may be made by those skilled in the art without departing from the spirit of the present invention, and shall also fall within the scope of the claims of the present invention.