A readable anti-clogging coal powder isokinetic sampling system with air extraction flow and working method

Abstract

The invention discloses an exhaust flow readable anti-clogging coal powder isokinetic sampling system and a working method, which belong to the field of test and measurement of pulverizing systems. The system comprises a coal powder sampling gun, a wind speed measuring instrument, a primary coal powder separator, a secondary coal powder separator, an exhaust flow meter, a No. 1 valve, an exhaust fan, a No. 1 throughflow flow meter, a No. 1 throughflow pipeline, a No. 4 throughflow pipeline, a No. 2 throughflow flow meter, a No. 2 throughflow pipeline, a No. 3 throughflow pipeline and a throughflow fan. Due to the adoption of measures such as throughflow medium and readable exhaust flow, the invention can thoroughly solve the problems that the pressure measuring holes of the existing sampling devices are easily blocked and the sampling state is difficult to control.

Description

Technical Field

[0001] The invention relates to an air extraction flow readable anti-clogging coal powder isokinetic sampling system and a working method, belonging to the field of test measurement of pulverizing systems. Background Art

[0002] Coal-fired power plant boilers are basically pulverized coal boilers. The pulverizing system is an important auxiliary equipment of the boiler. The safety and economy of boiler operation are closely related to the operating parameters of the pulverizing system. An important parameter for evaluating the pulverizing system is the fineness and uniformity index of the pulverized coal. Therefore, it is extremely important to perform isokinetic sampling to obtain qualified pulverized coal for laboratory analysis.

[0003] The pressure measuring holes of the instruments currently specified in national standards are easily clogged during use, and there is no effective means to determine whether they are clogged during the sampling process. The only way to determine whether the sampling is normal is based on the number of samples taken and experience after the sampling is completed. If it is abnormal, re-sampling will be carried out, resulting in low efficiency and low accuracy of the test work.

[0004] Based on the above reasons, in order to effectively solve the problem that the pressure measuring holes of the above-mentioned measuring device are easily blocked and whether the sampling status is normal cannot be judged, a new coal powder isokinetic sampling system needs to be developed. Summary of the invention

[0005] The present invention aims to completely solve the problem that the measuring device is easy to be blocked and the sampling state is difficult to control, and provides a suction flow readable anti-blocking type coal powder isokinetic sampling system.

[0006] The technical solution adopted by the present invention to solve the above-mentioned problem is: an exhaust flow readable anti-clogging coal powder isokinetic sampling system, which is characterized in that it includes a coal powder sampling gun, a wind speed measuring instrument, a primary coal powder separator, a secondary coal powder separator, an exhaust flowmeter, a No. 1 valve, an exhaust fan, a No. 1 flow flowmeter, a No. 1 flow pipe, a No. 4 flow pipe, a No. 2 flow flowmeter, a No. 2 flow pipe, a No. 3 flow pipe and a flow fan; the flow fan is connected to the No. 1 flow flowmeter and the No. 2 flow flowmeter through the No. 4 flow pipe and the No. 3 flow pipe respectively, the No. 1 flow flowmeter and the No. 2 flow flowmeter are connected to the No. 1 flow pipe and the No. 2 flow pipe respectively, and the No. 1 flow pipe and the No. 2 flow pipe are connected to the full-pressure conduction pipeline inside the gun body through the circulating air inlet at the rear end of the coal powder sampling gun. And the static pressure transmission pipeline inside the gun body; the front end of the coal powder sampling gun is provided with an airflow total pressure collection hole and an airflow static pressure collection hole, the airflow total pressure collection hole is connected with the airflow total pressure measurement joint arranged on the side wall of the coal powder sampling gun through the total pressure transmission pipeline inside the gun body, the airflow static pressure collection hole is connected with the airflow static pressure measurement joint arranged on the side wall of the coal powder sampling gun through the static pressure transmission pipeline inside the gun body, the airflow total pressure measurement joint and the airflow static pressure measurement joint are both connected with the wind speed measuring instrument; the front end of the coal powder sampling gun is also provided with a coal powder sampling port, the coal powder sampling port is connected to the first-level coal powder separator through the internal pipeline of the gun body and the exhaust port at the rear end of the coal powder sampling gun, the first-level coal powder separator, the second-level coal powder separator and the exhaust flow meter are connected in sequence, and the exhaust flow meter is connected to the exhaust fan through valve No. 1.

[0007] Furthermore, the exhaust fan is connected to a branch line, and a No. 2 valve is installed on the branch line.

[0008] Furthermore, the airflow total pressure collection hole and the airflow static pressure collection hole are respectively arranged on the windward side and the leeward side of the coal powder sampling gun, and the flow velocity of the measured medium is calculated by measuring the total pressure and the static pressure; during measurement, the total pressure transmission pipeline inside the gun body and the static pressure transmission pipeline inside the gun body are both passed through by air from the flow fan, and the air finally enters the measured medium through the airflow total pressure collection hole and the airflow static pressure collection hole. Due to the flow of air, the airflow total pressure collection hole, the airflow static pressure collection hole, the total pressure transmission pipeline inside the gun body and the static pressure transmission pipeline inside the gun body will not be blocked due to the deposited coal powder even when measuring the flow velocity of the powder-carrying airflow.

[0009] Furthermore, according to the flow rate measured by the anemometer, the exhaust flow rate is controlled by adjusting valve No. 1 at the exhaust fan inlet, so that the exhaust flow meter reads the corresponding exhaust pipe velocity and the measured flow rate of the measured medium. At this time, the sampling is in an isokinetic sampling state.

[0010] Furthermore, the medium flow rate in the measured pipeline can be measured separately according to other speed measuring devices, and then the coal powder sampling gun can be inserted for sampling, and the exhaust flow rate can be adjusted so that the flow rate measured independently in advance is the same as the speed in the corresponding pipe read by its flow meter.

[0011] Furthermore, the structures of the static pressure transmission pipeline inside the gun body and the total pressure transmission pipeline inside the gun body are designed to be similar to ensure the same fluid resistance characteristics (same resistance under the same flow rate), and the relationship between the measurement parameters is as follows:

[0012]

[0013]

[0014] λ1=λ2

[0015] υ1=υ2

[0016] ξ1=ξ2

[0017] In the formula: λ is the resistance coefficient along the pressure transmission pipeline, ζ is the local resistance coefficient of the pressure transmission pipeline, l is the pipeline length of the pressure transmission pipeline, d is the pipeline hydraulic diameter of the pressure transmission pipeline, v is the flow velocity in the pressure transmission pipeline, P'4 is the total pressure measurement value under flow condition, P'5 is the static pressure measurement value under flow condition, P4 is the total pressure measurement value under no flow condition, and P5 is the static pressure measurement value under no flow condition.

[0018] During measurement, flow is allowed to flow through the static pressure transmission pipeline inside the gun body and the total pressure transmission pipeline inside the gun body, and the flow rate of the flowing medium is kept at a small value, and the flow rates of the two are ensured to be equal (Q1=Q2). At this time, the pipeline resistance generated by the flowing medium on the two is the same. Under this condition, the above formula can be used to calculate P4-P5=P'4-P'5. Therefore, the dynamic pressure △P=P4-P5 that characterizes the flow rate of the measured medium can be obtained through the measured values ​​of P'4 and P'5.

[0019] The working method of the exhaust flow readable anti-clogging coal powder isokinetic sampling system is characterized in that the process is as follows: turn on the flow fan, adjust the No. 1 flow flow meter and the No. 2 flow flow meter to make the flow rate of the flow medium in the total pressure transmission pipeline inside the gun body and the static pressure transmission pipeline inside the gun body equal and maintain a small flow rate, use a pressure gauge to connect the airflow full pressure measurement joint to measure the total pressure P'4, use a pressure gauge to connect the airflow static pressure measurement joint to measure the static pressure P'5; when there is no flow, the airflow full pressure measurement joint measures the total pressure value P4, and when there is no flow, the airflow static pressure measurement joint measures the static pressure P'5. The static pressure value P5, because of the control of the flow rate, characterizes the dynamic pressure △P=P4-P5=P'4-P'5 of the flow velocity of the measured medium, and then the flow velocity of the measured medium is further calculated through the relationship formula between dynamic pressure and flow velocity; at the same time, the coal powder sampling port is facing the incoming flow, and the total pressure and static pressure are measured by the wind speed measuring instrument, which intuitively displays the flow velocity of the measured medium in the pipe; according to this flow velocity, adjust valve No. 1 and valve No. 2 to control the flow of the exhaust flowmeter so that the corresponding sampling tube exhaust speed displayed by it is equal to the wind speed measured by the wind speed measuring instrument, and the isokinetic sampling state is reached at this time.

[0020] Compared with the prior art, the present invention has the following advantages and effects: a small amount of airflow is passed through the system and sprayed into the measured medium, which can effectively prevent the blockage of the pressure measuring tube and ensure normal speed measurement; the structural design of the static pressure transmission pipeline inside the gun body and the total pressure transmission pipeline inside the gun body is similar, ensuring the same fluid resistance characteristics (same resistance under the same flow rate), and when measuring, the static pressure transmission pipeline inside the gun body and the total pressure transmission pipeline inside the gun body are allowed to flow and the flow rate of the flowing medium is kept at a small value, and the flow rates of the two are ensured to be equal (Q1=Q2), and the dynamic pressure △P representing the flow rate of the measured medium is P4-P5=P'4-P'5, ensuring the accuracy of the speed measurement data; the flow rate in the measured medium pipe can be read, and it can be judged whether the pressure measuring tube is blocked; the air extraction flow is displayed, and it can be judged whether the sampling working state is normal. Through the above approach, the problem that the pressure measuring hole of the existing sampling device is easy to be blocked and the sampling state is difficult to control is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the system in an embodiment of the present invention.

[0022] Figure 2 yes Figure 1 Schematic diagram of the BB cross section.

[0023] Figure 3 yes Figure 1 Partial view in the direction of A.

[0024] In the figure: airflow total pressure collection hole 1, airflow static pressure collection hole 2, coal powder sampling gun 3, airflow total pressure measurement joint 4, airflow static pressure measurement joint 5, wind speed measuring instrument 6, primary coal powder separator 7, secondary coal powder separator 8, exhaust flowmeter 9, No. 1 valve 10, No. 2 valve 11, exhaust fan 12, No. 1 flow flowmeter 13, No. 1 flow pipe 14, No. 2 flow flowmeter 15, static pressure transmission pipeline inside the gun body 16, total pressure transmission pipeline inside the gun body 17, flow fan 18, No. 2 flow pipe 19, No. 3 flow pipe 20, No. 4 flow pipe 21, coal powder sampling port 22. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and by way of examples. The following examples are intended to explain the present invention but the present invention is not limited to the following examples.

[0026] See also Figures 1 to 3 A suction flow readable anti-clogging coal powder isokinetic sampling system comprises a coal powder sampling gun 3, an anemometer 6, a primary coal powder separator 7, a secondary coal powder separator 8, an air suction flowmeter 9, a No. 1 valve 10, an air suction fan 12, a No. 1 flow meter 13, a No. 1 flow pipe 14, a No. 4 flow pipe 21, a No. 2 flow meter 15, a No. 2 flow pipe 19, a No. 3 flow pipe 20 and a flow fan 18; the flow fan 18 is connected to the No. 1 flow meter 13 and the No. 2 flow meter 15 through the No. 4 flow pipe 21 and the No. 3 flow pipe 20 respectively, the No. 1 flow meter 13 and the No. 2 flow meter 15 are connected to the No. 1 flow pipe 14 and the No. 2 flow pipe 19 respectively, and the No. 1 flow pipe 14 and the No. 2 flow pipe 19 are connected to the full pressure transmission pipeline 1 inside the gun body through the circulating air inlet at the rear end of the coal powder sampling gun 3. 7 is connected to the static pressure transmission pipeline 16 inside the gun body; the front end of the coal powder sampling gun 3 is provided with an airflow total pressure collection hole 1 and an airflow static pressure collection hole 2, the airflow total pressure collection hole 1 is connected to the airflow total pressure measurement joint 4 set on the side wall of the coal powder sampling gun 3 through the total pressure transmission pipeline 17 inside the gun body, the airflow static pressure collection hole 2 is connected to the airflow static pressure measurement joint 5 set on the side wall of the coal powder sampling gun 3 through the static pressure transmission pipeline 16 inside the gun body, and the airflow total pressure measurement joint 4 and the airflow static pressure measurement joint 5 are both connected to the wind speed measuring instrument 6; the front end of the coal powder sampling gun 3 is also provided with a coal powder sampling port 22, the coal powder sampling port 22 is connected to the first-level coal powder separator 7 through the internal pipeline of the gun body and the exhaust port at the rear end of the coal powder sampling gun 3, the first-level coal powder separator 7, the second-level coal powder separator 8, and the exhaust flowmeter 9 are connected in sequence, and the exhaust flowmeter 9 is connected to the exhaust fan 12 through the No. 1 valve 10.

[0027] Specifically, the exhaust fan 12 is connected to a branch line, and a No. 2 valve 11 is installed on the branch line.

[0028] Specifically, the airflow total pressure collection hole 1 and the airflow static pressure collection hole 2 are respectively arranged on the windward side and the leeward side of the coal powder sampling gun 3, and the flow velocity of the measured medium is calculated by measuring the total pressure and the static pressure; during measurement, the total pressure transmission pipeline 17 inside the gun body and the static pressure transmission pipeline 16 inside the gun body are both passed with air from the flow fan 18, and the air finally enters the measured medium through the airflow total pressure collection hole 1 and the airflow static pressure collection hole 2. Due to the flow of air, the airflow total pressure collection hole 1, the airflow static pressure collection hole 2, the total pressure transmission pipeline 17 inside the gun body and the static pressure transmission pipeline 16 inside the gun body will not be blocked due to the deposited coal powder even when measuring the flow velocity of the powder-carrying airflow.

[0029] Specifically, according to the flow rate measured by the anemometer 6, the exhaust flow rate is controlled by adjusting the No. 1 valve 10 at the inlet of the exhaust fan 12, so that the exhaust flow meter 9 reads the corresponding exhaust pipe velocity and the measured flow rate of the measured medium. At this time, the sampling is in an isokinetic sampling state.

[0030] Specifically, the medium flow rate in the measured pipeline can be measured separately according to other velocity measuring devices, and then the coal powder sampling gun 3 is inserted for sampling, and the exhaust flow rate is adjusted so that the flow rate measured independently in advance is the same as the velocity in the corresponding pipe read by its flow meter.

[0031] The working method of the exhaust flow readable anti-clogging coal powder isokinetic sampling system is as follows: turn on the flow fan 18, adjust the No. 1 flow flow meter 13 and the No. 2 flow flow meter 15, so that the flow rate of the flow medium in the total pressure transmission pipeline 17 inside the gun body and the static pressure transmission pipeline 16 inside the gun body are equal and maintain a small flow rate, use a pressure gauge to connect the airflow full pressure measurement connector 4 to measure the total pressure P'4, and use a pressure gauge to connect the airflow static pressure measurement connector 5 to measure the static pressure P'5; when there is no flow, the total pressure value P4 is measured at the airflow full pressure measurement connector 4, and the static pressure value P' is measured at the airflow static pressure measurement connector 5 when there is no flow. The static pressure value P5, because of the control of the flow rate, characterizes the dynamic pressure △P=P4-P5=P'4-P'5 of the flow velocity of the measured medium, and then the flow velocity of the measured medium is further calculated through the relationship formula between dynamic pressure and flow velocity; at the same time, the coal powder sampling port 22 is facing the incoming flow, and the total pressure and static pressure are measured by the wind speed measuring instrument 6, which intuitively displays the flow velocity of the measured medium in the pipe; according to this flow velocity, adjust the No. 1 valve 10 and the No. 2 valve 11 to control the flow of the exhaust flowmeter 9 so that the corresponding sampling tube exhaust speed displayed by it is equal to the wind speed measured by the wind speed measuring instrument 6, and the isokinetic sampling state is reached at this time.

[0032] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0033] Although the present invention has been disclosed as above by way of embodiments, it is not intended to limit the protection scope of the present invention. Any changes and modifications made by any technician familiar with the technology without departing from the concept and scope of the present invention should fall within the protection scope of the present invention.

Claims

1. A working method of a readable anti-clogging coal powder isokinetic sampling system with air extraction flow, characterized in that: The system comprises a coal powder sampling gun (3), an anemometer (6), a primary coal powder separator (7), a secondary coal powder separator (8), an exhaust flow meter (9), a No. 1 valve (10), an exhaust fan (12), a No. 1 flow meter (13), a No. 1 flow pipe (14), a No. 4 flow pipe (21), a No. 2 flow meter (15), a No. 2 flow pipe (19), a No. 3 flow pipe (20) and a flow fan (18); the flow fan (18) is respectively connected to the No. 4 flow pipe (14) and the No. 4 flow pipe (21). The first through-flow pipe (21) and the third through-flow pipe (20) are connected to the first through-flow flow meter (13) and the second through-flow flow meter (15); the first through-flow flow meter (13) and the second through-flow flow meter (15) are respectively connected to the first through-flow pipe (14) and the second through-flow pipe (19); the first through-flow pipe (14) and the second through-flow pipe (19) are respectively connected to the total pressure transmission pipe (17) inside the gun body and the static pressure transmission pipe (19) inside the gun body through the circulating air inlet at the rear end of the coal powder sampling gun (3). 16) connected; the front end of the coal powder sampling gun (3) is provided with an airflow total pressure collection hole (1) and an airflow static pressure collection hole (2); the airflow total pressure collection hole (1) is connected to the airflow total pressure measurement joint (4) arranged on the side wall of the coal powder sampling gun (3) through the total pressure transmission pipeline (17) inside the gun body; the airflow static pressure collection hole (2) is connected to the airflow static pressure measurement joint (5) arranged on the side wall of the coal powder sampling gun (3) through the static pressure transmission pipeline (16) inside the gun body; the airflow total pressure measurement joint (4) is connected to the airflow static pressure measurement joint (5) arranged on the side wall of the coal powder sampling gun (3) ) and the airflow static pressure measurement joint (5) are both connected to the anemometer (6); the front end of the coal powder sampling gun (3) is also provided with a coal powder sampling port (22), the coal powder sampling port (22) is connected to the primary coal powder separator (7) via the internal pipeline of the gun body and the exhaust port at the rear end of the coal powder sampling gun (3), the primary coal powder separator (7), the secondary coal powder separator (8), and the exhaust flow meter (9) are connected in sequence, and the exhaust flow meter (9) is connected to the exhaust fan (12) via the No. 1 valve (10); The airflow total pressure collection hole (1) and the airflow static pressure collection hole (2) are respectively arranged on the windward side and the leeward side of the coal powder sampling gun (3), and the flow rate of the measured medium is calculated by measuring the total pressure and the static pressure. During measurement, the total pressure transmission pipeline (17) inside the gun body and the static pressure transmission pipeline (16) inside the gun body are both ventilated with air from the through-flow fan (18), and the air finally enters the measured medium through the airflow total pressure collection hole (1) and the airflow static pressure collection hole (2). Due to the through-flow air, the airflow total pressure collection hole (1), the airflow static pressure collection hole (2), the gun body total pressure transmission pipeline (17) and the gun body static pressure transmission pipeline (16) are not blocked due to the deposition of coal powder even when the flow rate of the airflow with powder is measured. The working method is as follows: start the flow fan (18), adjust the No. 1 flow meter (13) and the No. 2 flow meter (15), so that the flow rate of the flow medium in the total pressure transmission pipeline (17) inside the gun body and the static pressure transmission pipeline (16) inside the gun body are equal and maintain a small flow rate, and use a pressure gauge to connect the airflow total pressure measurement joint (4) to measure the total pressure. P ， 4 , use a pressure gauge to connect the static pressure measuring connector (5) to measure the static pressure. P ， 5 ; When there is no flow, the total pressure measurement connector (4) measures the total pressure value P 4 , static pressure value measured by the static pressure measuring connector (5) when no flow is passing P 5 , because of the control of the flow rate, the dynamic pressure that represents the flow rate of the measured medium △P=P 4 -P 5 =P ， 4 -P ， 5 , and then the flow rate of the measured medium is further calculated by the relationship formula between dynamic pressure and flow rate; at the same time, the coal powder sampling port (22) is directly facing the incoming flow, and the total pressure and static pressure are measured by the wind speed measuring instrument (6), which intuitively displays the flow rate of the measured medium in the pipe; based on this flow rate, the No. 1 valve (10) and the No. 2 valve (11) are adjusted to control the flow of the exhaust flow meter (9) so that the exhaust speed of the corresponding sampling pipe displayed by the No. 1 valve (10) is equal to the wind speed measured by the wind speed measuring instrument (6), and the isokinetic sampling state is achieved at this time.

2. The working method of the exhaust flow readable anti-clogging coal powder isokinetic sampling system according to claim 1 is characterized in that: The exhaust fan (12) is connected to a branch line, and a No. 2 valve (11) is installed on the branch line.

3. The working method of the exhaust flow readable anti-clogging coal powder isokinetic sampling system according to claim 1 is characterized in that: According to the flow velocity measured by the wind speed measuring instrument (6), the exhaust flow rate is controlled by adjusting the No. 1 valve (10) at the inlet of the exhaust fan (12), so that the corresponding velocity in the exhaust pipe read by the exhaust flow meter (9) is the same as the measured flow velocity of the measured medium. At this time, the sampling is in an isokinetic sampling state.

4. The working method of the exhaust flow readable anti-clogging coal powder isokinetic sampling system according to claim 1 is characterized in that: Alternatively, the medium flow rate in the measured pipeline may be measured separately using other velocity measuring devices, and then the coal powder sampling gun (3) may be inserted for sampling, and the air extraction flow rate may be adjusted so that the flow rate measured independently in advance is the same as the flow rate in the corresponding pipe read by the flow meter.

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