CN110864773B - Method and system for online checking accuracy of solid flow meter - Google Patents

Abstract

The invention provides a method and a system for on-line inspection of the accuracy of a solid flowmeter. First, a comparison pipeline with the same diameter as the conveying pipeline where the solid flowmeter to be inspected is installed is set up; the powder mass flow of the solid flowmeter to be inspected is read; Convey the same powder as that in the pipeline to be tested to the comparison pipeline, and set the powder feeding rate equal to the value displayed by the solid flowmeter to be tested; secondly, detect the static pressure of the conveying air in the pipeline to be tested and the comparison pipeline, and adjust it to The static pressure of the two pipelines is the same; the wind speed in the pipeline to be tested and the comparison pipeline is detected, and the wind speed of the two pipelines is adjusted to be the same; finally, on the pipeline to be tested and the comparison pipeline, the pipe sections with the same length are selected to detect the two pipe sections respectively. Pressure drop signal; compare and analyze the pressure drop characteristics on the two pipe sections to judge the accuracy of the solid flowmeter to be tested. The inspection device is designed according to the method, and the structure is simple, and the fast inspection of the solid flowmeter can be realized without affecting the transportation work of the pipeline to be inspected.

Description

Method and system for on-line inspection of accuracy of solid flowmeter

technical field

The invention relates to a method and a system for checking flowmeters in the field of measurement and detection, in particular to an on-line checking method and system for the accuracy of solid flowmeters.

Background technique

The precise transportation of powder has important requirements in chemical, power generation, metallurgy and other industries, such as coal powder feeding in coal gasification process, solid adsorbent injection in thermal power flue gas treatment process and other applications. Usually, a solid flow meter is used to monitor the mass flow of the powder, and at the same time adjust the amount of powder to control the mass flow of the powder.

However, in the long-term use process of solid flowmeter, it is often necessary to recalibrate or check its accuracy, such as: 1. Due to factors such as powder particle adhesion and deposition, the accuracy will be affected; 2. If the powder conveying material is replaced, When the physical properties change, the flowmeter needs to be checked and calibrated again; 3. At the same time, the change of the wind speed of the powder conveying pipeline will lead to the change of the flow pattern of the pneumatic conveying, and the flowmeter also needs to be checked and calibrated.

Most of the existing solid flowmeter inspection devices and methods are based on the weighing method, and the solid flowmeter to be inspected is inspected according to the weighing data. Therefore, the inspection process generally takes a long time, and the device is relatively complicated. When inspecting, it is often necessary to interrupt the original transportation. process to weigh.

Patent CN101545801A provides a device and method for testing a solid mass flowmeter. The device includes a set of dry feeding device, which uses a weighing tank to collect and weigh the sent powder, and is equipped with a dust removal device to prevent the powder from flowing out with the carrier gas, so as to ensure the reliability of the weighing data; although this patent realizes It can accurately test the solid flowmeter, but the device is complicated and occupies a large space, which is easily limited by space when used.

Patent CN102140371A provides a device and method for testing solid mass flowmeter. The device includes a set of dry feeding device. The powder is weighed by a weighing tank before feeding into the feeding device to ensure the accuracy of the weighing data; although this patent realizes the accurate calibration of the solid flowmeter However, the use of weighing data accumulation method to reduce errors leads to a long calibration time, and it is impossible to quickly and real-time test the accuracy of the solid flowmeter.

To sum up, the existing solid flowmeter inspection devices have complicated devices, long inspection time, and often need to interrupt the original pneumatic conveying process during inspection. The solid flow meter inspection device.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an on-line inspection method and system for the accuracy of a solid flowmeter, which is used to solve the problems that the current traditional solid flowmeter detection device is complex and the traditional weighing data accumulation method takes a long time. When the solid flowmeter inspection device is inspected, it is often necessary to interrupt the original pneumatic conveying process.

In order to solve the above problems, the present invention considers that in the powder transportation, due to the acceleration of the gas phase and the particle phase, the collision and friction with the tube wall, the friction between the gas and the particles, etc., the gas-solid two phases will generate pressure during the movement process. Different powder conveying concentrations, conveying pipelines have different pressure drop characteristics. Based on the knowledge that the main core parameters of pneumatic conveying are the same (the conveying air pressure and airflow velocity are the same, and the powder type and powder mass flow rate are the same), the conveying pipelines with the same diameter should have similar pressure drop characteristics. Simple and reliable on-line inspection method and system for accuracy of solid flowmeter without interrupting the original pneumatic conveying process:

The present application designs a method for on-line inspection of the accuracy of a solid flowmeter,

a. First, set up a comparison pipeline with the same diameter as the pipeline to be inspected, and read the powder mass flow data of the solid flow meter to be inspected on the pipeline to be inspected; the storage and transportation pipelines to be inspected are stored in the silo of the sending device. The powder material with the same material is conveyed in the middle; the powder is conveyed to the comparison pipeline through the feeding device, and the powder feeding rate of the feeding device is set to be equal to the powder mass flow data of the solid flowmeter to be tested;

b. Secondly, check the static pressure of the conveying air in the pipeline to be inspected and the comparison pipeline, adjust the static pressure of the conveying air in the comparison pipeline until the static pressure of the conveying air in the two pipelines is the same; , adjust the wind speed in the comparison pipeline until the wind speed of the two pipelines is the same;

c. Detect the pressure drop signal between the two measuring points with the distance L on the pipeline to be inspected, and detect the pressure drop signal between the two measuring points with the same distance L on the comparison pipeline;

d. Compare the pressure drop signal of the pipeline to be inspected and the pressure drop signal of the contrast pipeline, and comprehensively analyze the pressure drop characteristics of the two groups of pressure drop signals, so as to judge the accuracy of the solid flowmeter to be inspected.

When the powder in the pipeline to be inspected or the pipeline transportation environment changes, the accuracy of the solid flowmeter to be inspected can be checked online by the same method by adjusting the powder in the feeding device or comparing the pipeline transportation environment.

Further, the specific judgment method of the solid flowmeter to be tested is:

为ΔP₁(n)的平均值；ΔP₂(n)为一定时间间隔t内，以采样频率f对对比管道两测量点间的压降进行测量，所获压降采样值；

为ΔP₂(n)的平均值；S₁为待检输送管道压降信号的标准差；S₂为对比管道压降信号的标准差；Define the data parameters of the pressure drop signal in the pipeline to be tested and the comparison pipeline: ΔP ₁ (n) is within a certain time interval t, measure the pressure drop between the two measurement points of the pipeline to be tested at the sampling frequency f, and the obtained pressure drop sample value;

is the average value of ΔP ₁ (n); ΔP ₂ (n) is the sampling value of the pressure drop obtained by measuring the pressure drop between the two measurement points of the comparison pipeline with the sampling frequency f within a certain time interval t;

is the average value of ΔP ₂ (n); S ₁ is the standard deviation of the pressure drop signal of the pipeline to be inspected; S ₂ is the standard deviation of the pressure drop signal of the comparison pipeline;

The test results correspond to three situations:

且

判断待检固体流量计准确性符合要求；10 when

and

Judging that the accuracy of the solid flowmeter to be tested meets the requirements;

但

判断待检固体流量计准确性不符合要求；2○ when

but

Judging that the accuracy of the solid flowmeter to be tested does not meet the requirements;

无论是否存在

判定待检固体流量计准确性不符合要求；3○ when

whether or not it exists

It is judged that the accuracy of the solid flowmeter to be tested does not meet the requirements;

和

的计算方法为：

and

The calculation method is:

式中：N——一定时间间隔内压降采样信号内的采样数量，N＝f·t。S1 and _S2 are calculated as _:

In the formula: N——the number of samples in the voltage drop sampling signal in a certain time interval, N=f·t.

Further, the design of the present application sets the distance between the front and rear measurement points on the detection pipeline of the first differential pressure detector and the second differential pressure detector to be 4-8 times the diameter of the pipeline; the first differential pressure detector and the The sampling frequency f of the second differential pressure detector is set to 500HZ-2000HZ, and the sampling time t is 5S-30S.

Further, the mass flow rate of the powder conveyed by the feeding device to the comparison pipeline is controlled by adjusting the opening of the blanking valve; the fan provides the conveying air for the comparison pipeline, and the wind speed in the comparison pipeline is controlled by adjusting the opening degree of the fan valve; The opening of the pressure reducing valve controls the static pressure of the conveying air in the contrast pipeline. The mass flow of the powder will directly affect the degree of pressure drop of the powder during the movement: when the wind speed and static pressure of the conveying wind remain unchanged, the larger the powder flow, the greater the resistance during the movement, the same two. The greater the pressure drop between the two measurement points; on the contrary, when the powder flow rate is small, the resistance received during the movement is small, and the pressure drop between the same two measurement points is smaller.

Further, the transmission air static pressure detection data of the conveying pipeline to be inspected and the comparison pipeline are sent to the pressure reducing valve controller, and the opening of the pressure reducing valve is controlled by the pressure reducing valve controller; The test results are sent to the fan valve controller, and the fan valve controller is used to control the fan valve opening; the mass change data in the feeding device is detected by the quality sensor, and the powder mass flow data in the pipeline to be inspected is detected by the solid flow meter to be inspected, and the The data signals of the mass sensor and the solid flowmeter to be tested are sent to the blanking valve controller, and the opening of the blanking valve is controlled by the blanking valve controller. The automatic control of the pressure reducing valve, the fan valve and the feeding valve by the pressure reducing valve controller, the fan valve controller and the feeding valve controller according to the comparison test results is shorter than manual control and adjustment, and the timeliness is high.

Further, the static pressure of the conveying air in the conveying pipeline to be inspected is detected by the first static pressure detector, the static pressure in the surge tank is detected by the second static pressure detector, and the static pressure in the conveying pipeline to be inspected is detected by the first wind speed detector. The wind speed in the comparison pipeline is detected by the second wind speed detector, the pressure drop between the corresponding two measurement points in the pipeline to be tested is detected by the first differential pressure detector, and the pressure drop in the comparison pipeline is detected by the second differential pressure detector. Corresponds to the pressure drop between two measuring points.

When the measurement data of the second static pressure detector is greater than the measurement data of the first static pressure detector, increase the opening of the pressure reducing valve; when the measurement data of the second static pressure detector is smaller than that of the first static pressure detector When the measurement data of the second wind speed detector is greater than the measurement data of the first wind speed detector, reduce the opening degree of the fan valve; when the measurement data of the second wind speed detector is less than When the measurement data of the first wind speed detector is obtained, the opening degree of the fan valve is increased.

Preferably, the second wind speed detector detects and compares the measurement points in the pipeline corresponding to the positions where the first wind speed detector detects the measurement points in the pipeline to be tested; the second differential pressure detector detects and compares the two measurement points in the pipeline with the first wind speed detector. The differential pressure detector detects the corresponding positions of the two measuring points in the pipeline to be inspected.

Further, the pressure drop data between the two measurement points corresponding to the pipeline to be inspected and the comparison pipeline are collected by the data collector, and then the data collector transmits the data to the data processor, and the data processor can calculate the corresponding two pipelines. The standard deviation and average pressure drop of the pressure drop signals between the two measurement points, and the standard deviation and average pressure drop of the pressure drop signals between the two measurement points corresponding to the two pipelines can be compared and analyzed to determine the accuracy of the solid flowmeter to be tested. sex.

Design an on-line inspection system for the accuracy of solid flowmeter, including the pipeline to be inspected and the comparison pipeline with the same diameter as the pipeline to be inspected;

A solids flowmeter to be inspected is arranged in the conveying pipeline to be inspected, a first static pressure detector is arranged in front of the solids flowmeter to be inspected along the transmission direction of the powder material, and a first static pressure detector is arranged behind the solids flowmeter to be inspected The wind speed detector and the first differential pressure detector; the first static pressure detector is used to detect the static pressure of the conveying wind in the conveying pipeline to be inspected, and the first wind speed detector and the first differential pressure detector are used to detect the static pressure of the conveying air in the conveying pipeline to be inspected. Check the pipeline wind speed and the pressure drop signal between the two measurement points at the back end of the solid flow meter. A second static pressure detector is arranged on the pressure stabilization tank; a powder feeding port is arranged in the comparison pipe, and a second wind speed detector and a first air velocity detector are arranged behind the powder feeding port along the conveying direction of the powder material. Two differential pressure detectors; the second static pressure detector is used to detect the static pressure of the conveying air in the comparative pipeline, and the second wind speed detector and the second differential pressure detector are used to detect the pipeline wind speed and the two differential pressure detectors at the rear end of the powder feeding port in the comparative pipeline. The voltage drop signal between the measurement points. The distance between the two measurement points in the pipeline to be inspected detected by the first differential pressure detector is the same as the distance between the two measurement points in the comparison pipeline detected by the second differential pressure detector.

The discharge port of the feeding device is connected with the powder feeding port through the soft connection device, which is used to send powder to the comparison pipeline. Adjust the mass flow rate of powder material sent by the feeding device to the comparison pipeline per unit time; a mass sensor is installed on the feeding device to detect the quality change of the feeding device per unit time; a fan is installed on the inlet side of the comparison pipeline, and the outlet of the fan is connected to a voltage stabilizer The tank and the surge tank are provided with an exhaust pipe and a pressure reducing valve. The surge tank outlet is connected with the fan valve inlet, and the fan valve outlet is connected with the comparison pipeline inlet; the fan provides conveying air for the comparison pipeline, and the surge tank prevents the conveying air. Excessive pressure damages the fan, the pressure reducing valve is used to adjust the static pressure of the conveying air, and the fan valve is used to control the wind speed in the contrast pipe.

The signal output end of the first static pressure detector and the signal output end of the second static pressure detector are connected to the signal input end of the pressure reducing valve controller, and the data signals of the first static pressure detector and the second static pressure detector are sent to the pressure reducing valve. The pressure reducing valve controller, the signal output end of the pressure reducing valve controller is connected with the signal input end of the pressure reducing valve, and the pressure reducing valve controller controls the opening degree of the pressure reducing valve according to the detection result until the static pressure in the comparison pipeline and the pipeline to be inspected is static. The signal output end of the first wind speed detector and the signal output end of the second wind speed detector are connected with the signal input end of the fan valve controller, and the detection results of the first wind speed detector and the second wind speed detector are sent to the fan valve control The fan valve controller signal output end is connected with the fan valve signal input end, and the fan valve controller controls the fan valve opening according to the detection result until the wind speed in the comparison pipeline and the pipeline to be tested are the same.

The signal output end of the mass sensor and the signal output end of the solid flowmeter to be inspected are connected with the signal input end of the blanking valve controller, and the data measured by the mass sensor and the solids flowmeter to be inspected are sent to the blanking valve controller, and the blanking valve controller Control the opening of the feeding valve according to the test results, and keep the same data measured by the mass sensor and the solid flowmeter to be tested.

During measurement, when the feeding rate measured by the mass sensor is greater than the reading of the solid flowmeter to be tested, adjust the opening of the feeding valve; when the feeding rate measured by the mass sensor is smaller than the reading of the solid flowmeter to be tested, adjust the Large discharge valve opening.

The signal output terminal of the first differential pressure detector and the signal output terminal of the second differential pressure detector are connected to the signal input terminal of the data collector, and the measured data of the first differential pressure detector and the second differential pressure detector are sent to the data collector device. The pressure drop data between the two measurement points corresponding to the pipeline to be tested and the comparison pipeline are collected by the data collector, and the standard deviation of the pressure drop signals between the two measurement points corresponding to the two pipelines and the two pipelines can be calculated through the data processor. Corresponding to the average value of the pressure drop between the two measurement points, the standard deviation of the pressure drop signal between the two measurement points corresponding to the two pipelines and the average pressure drop between the two measurement points corresponding to the two pipelines can be compared and analyzed, and the solid to be tested can be judged. The accuracy of the flowmeter.

When the main core parameters of the two pneumatic conveying processes are the same (the conveying air pressure and air velocity are the same, the powder type is the same as the powder mass flow rate, and the conveying pipe diameter is the same), and the distance between the pressure difference measuring points is the same, the measured pressure drop characteristics The pressure difference method used in this application has obvious comparative significance at this time.

Further, in order to improve the detection accuracy of the differential pressure detector, the present application designs that the distance L between the two measurement points before and after the first and second differential pressure detectors detect the pipeline is equal to the diameter D of the pipeline. 4-8 times.

Further, in order to quickly compare and analyze the information collected by the data collector, the present application connects the data collector with the data processor, and through the data processor, the data of the first differential pressure detector and the second differential pressure detector are checked. By comparing and analyzing the pressure drop signal of the pipeline to be tested and the comparison pipeline, the requirement of rapid online inspection of the accuracy of the solid flowmeter can be achieved.

Beneficial effects:

As can be seen from the above technical solutions, the technical solution of the present invention provides a system and method for on-line inspection of the accuracy of solid flowmeters, and can achieve the following beneficial effects: 1. In the present invention, by setting a comparison pipeline, the quality of the powder in the comparison pipeline is set. When the flow rate, static pressure and wind speed are the same as the powder mass flow rate, static pressure and wind speed of the pipeline to be inspected, the pressure drop signal between the two measurement points with the same distance L between the pipeline to be inspected and the comparison pipeline can be detected and compared. Analyzing and judging the accuracy of the solid flowmeter to be inspected greatly simplifies the solid flowmeter on-line inspection device; 2. The inspection of the solid flowmeter in the present invention belongs to an online inspection, and the inspection is fast and time-consuming; 3. The present invention is In the process of continuous powder conveying, the accuracy of the solid flowmeter to be inspected is judged by comparing and analyzing the pressure drop data between the two measuring points with the same distance between the pipeline to be inspected and the comparison pipeline, without interrupting the pneumatic conveying process in the pipeline to be inspected. . 4. Based on the detection principle of the present invention, the present invention can realize the on-line inspection of the solid flowmeter under the conveying pipeline for powders of various different powders and different conveying gas speeds to be inspected.

It is to be understood that all combinations of the foregoing concepts, as well as additional concepts described in greater detail below, are considered to be part of the inventive subject matter of the present disclosure to the extent that such concepts are not contradictory.

The foregoing and other aspects, embodiments and features of the present teachings can be more fully understood from the following description when taken in conjunction with the accompanying drawings. Other additional aspects of the invention, such as features and/or benefits of the exemplary embodiments, will be apparent from the description below, or learned by practice of specific embodiments in accordance with the teachings of this invention.

Description of drawings

The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures may be represented by the same reference numeral. For clarity, not every component is labeled in every figure. Embodiments of various aspects of the present invention will now be described by way of example and with reference to the accompanying drawings, wherein:

FIG. 1 is a schematic diagram of the system of the present invention.

The meanings of the reference numerals in the figure are as follows: 1. The first static pressure detector; 2. The quality sensor; 3. The support of the feeding device; 4. The pressure reducing valve controller; 5. The feeding device; Pressure detector; 7. Decompression valve; 8. Fan; 9. Exhaust pipe; 10. Pressure stabilization tank; 11. Fan valve; 12. Comparison pipeline; 13. Powder feeding port; 14. Soft connection device; 15. Feeding valve; 16. Second wind speed detector; 17. Second differential pressure detector; 18. Cyclone dust collector; 19. Fan valve controller; 20. Feeding valve controller; 21. Data processor; 22. Data collector; 23. Conveying pipeline to be inspected; 24. First differential pressure detector; 25. First wind speed detector; 26. Solid flowmeter to be inspected.

Detailed ways

In order to better understand the technical content of the present invention, specific embodiments are given and described below in conjunction with the accompanying drawings.

Aspects of the invention are described in this disclosure with reference to the accompanying drawings, in which a number of illustrative embodiments are shown. Embodiments of the present disclosure are not necessarily defined to include all aspects of the invention. It should be understood that the various concepts and embodiments described above, as well as those described in greater detail below, can be implemented in any of a number of ways, as the concepts and embodiments disclosed herein do not limited to any implementation. Additionally, some aspects of the present disclosure may be used alone or in any suitable combination with other aspects of the present disclosure.

In order to solve the problems that the existing solid flowmeter inspection device has complex device, long inspection time and can only inspect the solid flowmeter of a single working condition, the present application designs a method for on-line inspection of the accuracy of the solid flowmeter,

a. First, set up a comparison pipeline 12 with the same diameter as the conveying pipeline 23 to be inspected, and read the powder mass flow data of the solid flow meter 26 to be inspected on the conveying pipeline 23 to be inspected; The powder material is the same as the material conveyed in the conveying pipeline 23 to be inspected; the powder is conveyed to the comparison pipeline 12 through the feeding device 5, and the powder feeding rate of the feeding device 5 is set to be equal to the powder mass of the solid flow meter 26 to be inspected traffic data;

b. Next, detect the static pressure of the conveying wind in the conveying pipeline 23 to be inspected and the comparison pipeline 12, adjust the static pressure of the conveying air in the contrasting pipeline 12 until the static pressure of the conveying air in the two pipelines is the same; detect the wind speed in the conveying pipeline 23 to be inspected, and detect and compare For the wind speed in the pipeline 12, adjust the wind speed in the comparison pipeline 12 until the wind speed of the two pipelines is the same;

c. Detect the pressure drop signal between the two measuring points with the distance L on the conveying pipeline 23 to be inspected, and detect the pressure drop signal between the two measuring points with the same distance L on the comparison pipeline 12;

d. Compare the pressure drop signal between the two measurement points corresponding to the pipeline 23 to be inspected and the pressure drop signal between the two measurement points corresponding to the comparison pipeline 12, and comprehensively analyze the pressure drop characteristics of the two sets of pressure drop signals, so as to determine the pressure drop signal between the two groups of pressure drop signals. Check the accuracy of the solids flow meter 26 .

When the powder in the pipeline 23 to be inspected or the pipeline transportation environment changes, the accuracy of the solid flowmeter 26 to be inspected can be checked online by the same method by correspondingly adjusting the powder in the feeding device 5 or the transportation environment of the comparison pipeline 12 .

In specific implementation, the judgment method is as follows:

为ΔP₁(n)的平均值；ΔP₂(n)为一定时间间隔t内，以采样频率f对对比管道12两测量点间的压降进行测量，所获压降采样值；

为ΔP₂(n)的平均值；S₁为待检输送管道23压降信号的标准差；S₂为对比管道12压降信号的标准差；Define the pressure drop signal data parameters in the pipeline 23 to be tested and the comparison pipeline 12: ΔP ₁ (n) is within a certain time interval t, and the pressure drop between the two measurement points of the pipeline 23 to be tested is measured with the sampling frequency f, so Obtain the sampling value of pressure drop;

is the average value of ΔP ₁ (n); ΔP ₂ (n) is the pressure drop between the two measurement points of the comparison pipeline 12 is measured with the sampling frequency f within a certain time interval t, and the obtained pressure drop sampling value;

is the average value of ΔP ₂ (n); S ₁ is the standard deviation of the pressure drop signal of the pipeline 23 to be inspected; S ₂ is the standard deviation of the pressure drop signal of the comparison pipeline 12;

The test results correspond to three situations:

且

判断待检固体流量计26准确性符合要求；①When

and

Judging that the accuracy of the solid flow meter 26 to be inspected meets the requirements;

但

判断待检固体流量计26准确性不符合要求；②When

but

It is judged that the accuracy of the solid flow meter 26 to be inspected does not meet the requirements;

无论是否存在

判定待检固体流量计26准确性不符合要求；③When

whether or not it exists

It is determined that the accuracy of the solid flow meter 26 to be inspected does not meet the requirements;

和

的计算方法为：

and

The calculation method is:

S1 and _S2 are calculated as _:

In the formula: N—the number of samples in the voltage drop sampling signal in a certain time interval, N=f·t.

In the specific implementation, the present application designs to set the distance between the two measurement points before and after the first pressure difference detector 24 and the second pressure difference detector 17 on the detection pipeline to be 4-8 times the diameter of the pipeline; the first pressure difference The sampling frequency f of the detector 24 and the second differential pressure detector 17 is set to 500HZ-2000HZ, and the sampling time t is 5S-30S.

In the specific implementation, the mass flow rate of the powder conveying device 5 to the comparison pipeline 12 is controlled by adjusting the opening degree of the blanking valve 15; The wind speed in the pipeline 12; the static pressure of the conveying wind in the contrast pipeline 12 is controlled by adjusting the opening of the pressure reducing valve 7. The mass flow of the powder will directly affect the degree of pressure drop of the powder during the movement: when the wind speed and static pressure of the conveying wind remain unchanged, the larger the powder flow, the greater the resistance during the movement, the same two. The greater the pressure drop between the two measurement points; on the contrary, when the powder flow rate is small, the resistance received during the movement is small, and the pressure drop between the same two measurement points is smaller.

During specific implementation, the transmission pipeline 23 to be inspected and the static pressure detection result of the conveying air in the surge tank 10 are sent to the pressure reducing valve controller 4, and the opening degree of the pressure reducing valve 7 is controlled by the pressure reducing valve controller 4; The wind speed detection results in the inspection pipeline 23 and the comparison pipeline 12 are sent to the fan valve controller 19, and the opening degree of the fan valve 11 is controlled by the fan valve controller 19; The feeding valve controller 20 is used to control the opening of the feeding valve 15 through the feeding valve controller 20 . The automatic control of the pressure reducing valve 7, the fan valve 11 and the feeding valve 15 by the pressure reducing valve controller 4, the fan valve controller 19 and the feeding valve controller 20 according to the comparison and detection results is shorter than the time required for manual adjustment. , with high timeliness.

During specific implementation, the static pressure of the conveying air in the conveying pipeline 23 to be inspected is detected by the first static pressure detector 1 , the static pressure in the pressure stabilization tank 10 is detected by the second static pressure detector 6 , and the static pressure in the pressure stabilization tank 10 is detected by the second static pressure detector 6 , The wind speed in the pipeline 23 to be tested is detected, the wind speed in the comparison pipeline 12 is detected by the second wind speed detector 16, and the pressure drop between the corresponding two measurement points in the pipeline 23 to be tested is detected by the first differential pressure detector 24, The pressure drop between the corresponding two measurement points in the comparison pipeline 12 is detected by the second differential pressure detector 17 .

During measurement, when the measurement data of the second static pressure detector 6 is greater than the measurement data of the first static pressure detector 1, increase the opening of the pressure reducing valve 7; when the measurement data of the second static pressure detector 6 is smaller than the first static pressure detector 1 When the measurement data of a static pressure detector 1 is used, the opening of the pressure reducing valve 7 is reduced; when the measurement data of the second wind speed detector 16 is greater than the measurement data of the first wind speed detector 25, the opening of the fan valve 11 is reduced. When the measurement data of the second wind speed detector 16 is smaller than the measurement data of the first wind speed detector 25, the opening degree of the fan valve 11 is increased.

Preferably, the second wind speed detector 16 detects the measurement point in the comparison pipeline 12 corresponding to the position where the first wind speed detector 25 detects the measurement point in the conveying pipeline 23 to be tested; The two measurement points correspond to the positions of the two measurement points in the conveying pipeline 23 to be inspected detected by the first differential pressure detector 24 .

In specific implementation, the data collector 22 collects the pressure drop data between the two measurement points corresponding to the conveying pipeline 23 to be tested and the comparison pipeline 12, and then the data collector 22 transmits the data to the data processor 21, and the data processor 21 calculates The standard deviation of the pressure drop signal between the two measuring points corresponding to the two pipes and the average pressure drop between the two measuring points corresponding to the two pipes, and the standard deviation of the pressure drop signal between the two measuring points corresponding to the two pipes and the two pipes Corresponding to the average value of the pressure drop between the two measurement points, the accuracy of the solid flowmeter 26 to be inspected can be judged.

During specific implementation, as shown in FIG. 1 , the present application designs an on-line inspection system for the accuracy of solid flowmeters, including a conveying pipeline 23 to be inspected and a comparison pipeline 12 having the same diameter as the conveying pipeline 23 to be inspected;

A solid flowmeter 26 to be inspected is arranged in the conveying pipeline 23 to be inspected, and a first static pressure detector 1 is arranged in front of the solids flowmeter 26 to be inspected along the transmission direction of the powder material. The rear is provided with a first wind speed detector 25 and a first pressure difference detector 24; the first static pressure detector 1 is used to detect the static pressure of the conveying wind in the conveying pipeline 23 to be inspected, and the first wind speed detector 25 and the first pressure The difference detector 24 is used to detect the pipeline wind speed at the rear end of the solid flowmeter 26 to be inspected in the conveying pipeline 23 to be inspected and the pressure drop signal between the two measurement points. A second static pressure detector 6 is arranged on the pressure stabilization tank 10 , a powder feeding port 13 is arranged in the comparison pipe 12 , and a second static pressure detector 6 is arranged behind the powder feeding port 13 along the conveying direction of the powder material. The wind speed detector 16 and the second differential pressure detector 17; the second static pressure detector 6 is used to detect the static pressure of the wind conveyed by the contrast pipe 12, and the second wind speed detector 16 and the second differential pressure detector 17 are used to detect the contrast The wind speed of the pipeline at the rear end of the powder feeding port 13 in the pipeline 12 and the pressure drop signal between the two measurement points. The distance between the two measurement points in the conveying pipeline 23 to be tested detected by the first differential pressure detector 24 is the same as the distance between the two measurement points in the comparison pipeline 12 detected by the second differential pressure detector 17 .

The discharge port of the feeding device 5 is communicated with the powder feeding port 13 through the soft connecting device 14, and is used to send powder to the comparison pipe 12. The upper end of the discharging port of the feeding device 5 is provided with a lower part at the specific connection position. The material valve 15 is used to adjust the speed of the feeding device 5 sending powder to the comparison pipeline 12 per unit time; the quality sensor 2 is provided on the feeding device 5 to detect the quality change of the feeding device 5 per unit time; in the comparison pipeline 12 The inlet side is provided with a fan 8, the outlet of the fan 8 is connected to a surge tank 10, an exhaust pipe 9 and a pressure reducing valve 7 are arranged on the surge tank 10, the outlet of the surge tank 10 is connected to the inlet of the fan valve 11, and the outlet of the fan valve 11 It is connected with the inlet of the comparison pipeline 12; the blower 8 provides the conveying air for the comparison pipeline 12, the surge tank 10 prevents the blower 8 from being damaged by the excessive pressure of the conveying air, the pressure reducing valve 7 is used to adjust the static pressure of the conveying air, and the blower valve 11 is used to control Compare the wind speed in the duct 12 .

The signal output end of the first static pressure detector 1 and the signal output end of the second static pressure detector 6 are connected with the signal input end of the pressure reducing valve controller 4. The data signal is sent to the pressure reducing valve controller 4, the signal output end of the pressure reducing valve controller 4 is connected with the signal input end of the pressure reducing valve 7, and the pressure reducing valve controller 4 controls the opening of the pressure reducing valve 7 according to the detection result. Until the static pressure of the conveying air in the comparison pipeline 12 and the conveying pipeline 23 to be checked is the same; the signal output end of the first wind speed detector 25 and the signal output end of the second wind speed detector 16 are connected with the signal input end of the fan valve controller 19, The detection results of the first wind speed detector 25 and the second wind speed detector 16 are sent to the fan valve controller 19; the signal output end of the fan valve controller 19 is connected with the signal input end of the fan valve 11, and the fan valve controller 19 detects As a result, the opening degree of the fan valve 11 is controlled until the wind speed of the conveying air in the comparison pipe 12 and the conveying pipe 23 to be inspected is the same.

The signal output end of the mass sensor 2 and the signal output end of the solid flowmeter 26 to be inspected are connected with the signal input end of the blanking valve controller 20, and the data measured by the mass sensor 2 and the solids flowmeter 26 to be inspected are sent to the blanking valve controller 20. , the blanking valve controller 20 controls the opening of the blanking valve 15 according to the detection result until the data measured by the mass sensor 2 and the solid flowmeter 26 to be tested are the same.

During measurement, when the feeding rate obtained by the mass sensor 2 is greater than the reading of the solid flowmeter 26 to be tested, adjust the opening of the feeding valve 15; when the feeding rate obtained by the mass sensor 2 is less than the reading of the solid flowmeter 26 to be tested , increase the opening of the blanking valve by 15 degrees.

The signal output terminal of the first differential pressure detector 24 and the signal output terminal of the second differential pressure detector 17 are connected to the signal input terminal of the data collector 22. The measured values of the first differential pressure detector 24 and the second differential pressure detector 17 are The data is sent to the data collector 22 . The pressure drop data between the two measurement points corresponding to the conveying pipeline 23 to be tested and the comparison pipeline 12 are collected by the data collector 22, and the collected data is analyzed and compared by the data processor 21 to determine the solid flow meter 26 to be tested. accuracy.

When the main core parameters of the two pneumatic conveying processes are the same (the conveying air pressure and air velocity are the same, the powder type is the same as the powder mass flow rate, and the conveying pipe diameter is the same), and the distance between the pressure difference measuring points is the same, the measured pressure drop characteristics The pressure difference method used in this application has obvious comparative significance at this time.

Further, in the specific implementation, in order to improve the detection accuracy of the differential pressure detector, the present application designs the first differential pressure detector 24 and the second differential pressure detector 17 to detect the distance L between the two measurement points before and after the pipeline. It is 4-8 times the pipe diameter D.

During specific implementation, in order to quickly compare and analyze the information collected by the data collector 22, the present application connects the data collector 22 with the data processor 21, and through the data processor 21, the first differential pressure detector 24 and the second pressure difference detector 24 and the second Comparing and analyzing the pressure drop signal of the conveying pipeline 23 to be detected by the differential pressure detector 17 and the comparison pipeline 12 can meet the requirement of rapid on-line inspection of the accuracy of the solid flowmeter.

In specific implementation, the present application designs the feeding device 5 with a feeding device bracket 3 , and the mass sensor 2 is arranged on the feeding device bracket 3 , so that the quality sensor 2 can detect the quality change of the feeding device 5 per unit time.

In specific implementation, the present application designs a powder collector connected to the outlet end of the comparison pipe 12 for collecting the powder sent to the comparison pipe 12 by the feeding device 5 . Preferably, the powder collector is a cyclone 18 .

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Those skilled in the art to which the present invention pertains can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be determined according to the claims.

Claims (10)

1. A method for on-line checking the accuracy of a solid flow meter is characterized in that:

firstly, arranging a comparison pipeline with the same pipe diameter as a conveying pipeline to be detected, and reading powder mass flow data of a solid flowmeter to be detected on the conveying pipeline to be detected; the material sending device stores powder materials which are the same as the conveying materials in the conveying pipeline to be detected; powder is conveyed to a comparison pipeline through a material sending device, and the powder blanking speed of the material sending device is equal to the mass flow data of the powder of the solid flowmeter to be detected;

secondly, detecting the static pressure of the air conveyed in the conveying pipeline to be detected and the static pressure of the air conveyed in the comparison pipeline, and adjusting the static pressure of the air conveyed in the comparison pipeline until the static pressures of the air conveyed in the two pipelines are the same; detecting the wind speed in the conveying pipeline to be detected, detecting the wind speed in the comparison pipeline, and adjusting the wind speed in the comparison pipeline until the wind speeds of the two pipelines are the same;

detecting a pressure drop signal between two measuring points with the distance L on a conveying pipeline to be detected, and detecting and comparing a pressure drop signal between two measuring points with the distance L on the pipeline;

and comparing the pressure drop signal between the two measuring points of the conveying pipeline to be detected with the pressure drop signal between the two corresponding measuring points of the comparison pipeline, comprehensively analyzing the pressure drop characteristics of the two groups of pressure drop signals, and judging the accuracy of the solid flowmeter to be detected.

2. The method for on-line verification of accuracy of a solid flow meter of claim 1, wherein:

defining pressure drop signal data parameters in a conveying pipeline to be detected and a comparison pipeline: delta P₁(n) within a certain time interval t, measuring the pressure drop between two measuring points of the conveying pipeline to be detected by using the sampling frequency f to obtain a pressure drop sampling value;

is DeltaP₁(n) average value; delta P₂(n) within a certain time interval t, measuring the pressure drop between two measuring points of the comparison pipeline by using a sampling frequency f to obtain a pressure drop sampling value;

is DeltaP₂(n) average value; s₁The standard deviation of the pressure drop signal of the conveying pipeline to be detected is obtained; s₂Comparing the standard deviation of the pipeline pressure drop signals;

the detection result corresponds to three conditions:

firstly, when

And is

Judging whether the accuracy of the solid flowmeter to be detected meets the requirement;

② when

But do not

Judging that the accuracy of the solid flowmeter to be detected does not meet the requirement;

③ when

Whether or not present

And judging that the accuracy of the solid flowmeter to be detected does not meet the requirement.

3. The method for on-line verification of accuracy of a solid flow meter of claim 2, wherein: controlling the mass flow of the powder conveyed into the comparison pipeline by the material sending device by adjusting the opening degree of the blanking valve; the fan provides air for the comparison pipeline, and the air speed of the air in the comparison pipeline is controlled by adjusting the opening of a valve of the fan; the static pressure of the air conveyed in the pipeline is controlled and compared by adjusting the opening of the pressure reducing valve.

4. The method for on-line verification of accuracy of a solid flow meter of claim 3, wherein: conveying wind static pressure detection data of the conveying pipeline to be detected and the comparison pipeline are conveyed to a pressure reducing valve controller, and the opening of a pressure reducing valve is controlled through the pressure reducing valve controller; the wind speed detection data in the conveying pipeline to be detected and the comparison pipeline are transmitted to a fan valve controller, and the opening degree of a fan valve is controlled through the fan valve controller; the mass sensor is used for detecting mass change data in the material sending device, the solid flowmeter to be detected is used for detecting powder mass flow data in the conveying pipeline to be detected, the data are transmitted to the blanking valve controller, and the blanking valve opening is controlled through the blanking valve controller.

5. The method for on-line verification of accuracy of a solid flow meter of claim 4, wherein: the static pressure of conveying wind in the conveying pipeline to be detected is detected through the first static pressure detector, the static pressure in the pressure stabilizing tank is detected through the second static pressure detector, the wind speed in the conveying pipeline to be detected is detected through the first wind speed detector, the wind speed in the comparison pipeline is detected through the second wind speed detector, a pressure drop signal between two corresponding measuring points in the conveying pipeline to be detected is detected through the first pressure difference detector, and a pressure drop signal between two corresponding measuring points in the comparison pipeline is detected through the second pressure difference detector.

6. The method for on-line verification of accuracy of a solid flow meter of claim 5, wherein: setting the distance L between the front and back measuring points on the first differential pressure detector and the second differential pressure detector to be 4-8 times of the diameter D of the pipeline; the sampling frequency f of the first differential pressure detector and the second differential pressure detector is set to 500Hz to 2000Hz, and the sampling time t is set to 5S to 30S.

7. The method for on-line verification of accuracy of a solid flow meter of claim 6, wherein: pressure drop data between two corresponding measuring points of the conveying pipeline to be detected and the comparison pipeline are collected through the data collector and then transmitted to the data processor, and the standard deviation and the average pressure drop value of pressure drop signals between the two corresponding measuring points of the two pipelines can be calculated through the data processor.

8. An on-line inspection system for accuracy of a solid flow meter, comprising: comprises a conveying pipeline to be detected and a comparison pipeline with the same pipe diameter as the conveying pipeline to be detected;

a solid flow meter to be detected is arranged in the conveying pipeline to be detected, a first static pressure detector is arranged in front of the solid flow meter to be detected along the powder material conveying direction, and a first wind speed detector and a first differential pressure detector are arranged behind the solid flow meter to be detected; a second static pressure detector is arranged on the pressure stabilizing tank, a powder feeding hole is arranged in the comparison pipeline, and a second wind speed detector and a second pressure difference detector are arranged behind the powder feeding hole along the powder material conveying direction; the distance between two measuring points in the pipeline to be conveyed, which is detected by the first differential pressure detector, is the same as the distance between two measuring points in the comparison pipeline, which is detected by the second differential pressure detector;

the discharge hole of the material sending device is communicated with the powder feed inlet, and a discharge valve is arranged at the connecting position; the material sending device is provided with a quality sensor; a fan is arranged on the inlet side of the comparison pipeline, the outlet of the fan is connected with a pressure stabilizing tank, an exhaust pipe and a pressure reducing valve are arranged on the pressure stabilizing tank, the outlet of the pressure stabilizing tank is connected with the inlet of the fan valve, and the outlet of the fan valve is connected with the inlet of the comparison pipeline;

the signal output ends of the first static pressure detector and the second static pressure detector are connected with the signal input end of a pressure reducing valve controller, data signals of the first static pressure detector and the second static pressure detector are sent to the pressure reducing valve controller, the signal output end of the pressure reducing valve controller is connected with the signal input end of the pressure reducing valve, and the opening degree of the pressure reducing valve is controlled by the pressure reducing valve controller; the signal output end of the first air speed detector and the signal output end of the second air speed detector are connected with the signal input end of a fan valve controller, data signals of the first air speed detector and the second air speed detector are sent to the fan valve controller, the signal output end of the fan valve controller is connected with the signal input end of the fan valve, and the fan valve controller controls the opening degree of the fan valve; the signal output end of the mass sensor and the signal output end of the solid flowmeter to be detected are connected with the signal input end of a blanking valve controller, data signals of the mass sensor and the solid flowmeter to be detected are sent to the blanking valve controller, the signal output end of the blanking valve controller is connected with the signal input end of the blanking valve, and the blanking valve controller controls the opening of the blanking valve;

the signal output ends of the first pressure difference detector and the second pressure difference detector are connected with the signal input end of the data collector, and the first pressure difference detector and the second pressure difference detector send data signals to the data collector.

9. The solids flow meter accuracy online verification system of claim 8, wherein: the distance L between the front measuring point and the rear measuring point on the pipeline detected by the first differential pressure detector and the second differential pressure detector is 4-8 times of the diameter D of the pipeline.

10. The solids flow meter accuracy online verification system of claim 9, wherein: and the signal output end of the data acquisition unit is connected with the signal input end of the data processor, and the data processor is used for analyzing and comparing the data transmitted by the data acquisition unit to judge the accuracy of the solid flowmeter to be detected.

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