Boiler air volume sampling and regulating protection device for thermal power unit

Abstract

The present application relates to the field of thermal power unit boiler technology, especially to the thermal power unit boiler air volume sampling and adjusting protection device, including feed hopper, furnace and the like, the side of the feed hopper is connected with the coal inlet pipe, the top of the feed hopper is communicated with the furnace, the bottom pipe of the feed hopper is sequentially installed with the electromagnetic valve and the first fan, the cross sections of the bottom pipe of the feed hopper, the coal inlet pipe and the smoke exhaust pipe are all provided with flow meters, and the first baffle, the second baffle and the third baffle are respectively rotatably connected on these pipes, and the transmission mechanism is installed between the first baffle, the second baffle and the third baffle. The synchronous adjustment of each baffle is realized by the application of the transmission mechanism composed of the transmission wheel-belt, the adjustment lag is reduced, the air inlet volume and the smoke exhaust volume can be quickly balanced, the furnace pressure fluctuation is reduced, and the stability of the boiler combustion is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of boiler of thermal power unit, and particularly relates to a wind sampling and regulating protection device for boiler of thermal power unit. BACKGROUND

[0002] During the operation of the boiler of thermal power unit, accurate control of the wind volume is the key to guarantee the combustion efficiency and the operation safety. The traditional boiler wind volume control mode has many deficiencies. In terms of wind volume measurement, the single sampling mode and the measurement device vulnerable to dust interference result in large deviation of the measurement results, and it is difficult to accurately reflect the actual wind volume. In the regulating link, the control of the air inlet, coal supply and smoke exhaust system is relatively independent, and the response of each component is not synchronized, which causes the balance adjustment of the wind volume and the smoke exhaust volume to lag, and easily causes the furnace pressure fluctuation. At the same time, the safety protection mechanism is not perfect, lacks the multi-parameter collaborative judgment, and has the risk of misoperation or refusal to operate, which affects the stable operation of the unit.

[0003] Therefore, an accurate sampling, synchronous regulation and reliable protection device is needed to solve the above problems. SUMMARY

[0004] In order to overcome the shortcomings in the prior art, the technical problem of the present application is to provide a wind sampling and regulating protection device for boiler of thermal power unit.

[0005] The technical implementation scheme of the present application is: a wind sampling and regulating protection device for boiler of thermal power unit, comprising a feed hopper, a furnace, a coal inlet pipe, a smoke exhaust pipe, a burner, a first fan and an electromagnetic valve, the side of the feed hopper is connected with the coal inlet pipe, the top end of the feed hopper is communicated with the furnace, the side of the furnace is installed with the burner, the top end of the furnace is installed with the smoke exhaust pipe, the bottom end pipe of the feed hopper is sequentially installed with the electromagnetic valve and the first fan, further comprising a flow meter, a first partition plate, a second partition plate and a third partition plate, the cross sections of the bottom end pipe of the feed hopper, the coal inlet pipe and the smoke exhaust pipe are all provided with the flow meter, and the first partition plate, the second partition plate and the third partition plate are respectively rotationally connected on these pipes, a transmission mechanism is installed between the first partition plate, the second partition plate and the third partition plate to realize the synchronous angle regulation.

[0006] Further, a boiler drum, a water cooling pipe and a superheating pipe are further included, the boiler drum is installed on the inner wall of the furnace, the water cooling pipe is arranged on the inner wall and the superheating pipe is arranged on the upper part of the furnace, and a complete steam-water circulation loop is formed.

[0007] Further, a controller is further included, the controller is installed on the outer wall of the furnace and is electrically connected with the flow meter and the electromagnetic valve through the CAN bus.

[0008] Further, the flow meter comprises a buffer chamber, a baffle, an air inlet pipe, an air outlet pipe and a detector, the buffer chamber is divided into two unequal volume chambers by the baffle, the air inlet pipe is communicated with the high pressure chamber, the air outlet pipe is communicated with the low pressure chamber, and the detector adopts a differential pressure transmitter to measure the pressure difference of the two chambers.

[0009] Further, the transmission mechanism comprises a first transmission wheel, a second transmission wheel, a third transmission wheel and a fourth transmission wheel, the rotating shaft of the first partition plate is rigidly connected with the output shaft of the electromagnetic valve, and the first transmission wheel and the second transmission wheel are coaxially fixed, the rotating shafts of the second partition plate and the third partition plate are fixed with the third transmission wheel and the fourth transmission wheel respectively, the first transmission wheel is driven by the third transmission wheel through a belt, and the second transmission wheel is driven by the fourth transmission wheel through a belt, so that the angle of the three partition plates is synchronously adjusted.

[0010] Further, the second fan and the chimney are further arranged, the tail end of the smoke exhaust pipe is sequentially provided with the second fan and the chimney, and the second fan adopts frequency conversion speed control.

[0011] Further, the first partition plate and the second partition plate are initially in a closed state, and the third partition plate is initially in an open state.

[0012] Further, the flow meter is sampled at three points of a pipeline at the bottom end of the feeding hopper, the coal feeding pipe and the smoke exhaust pipe, so that accurate detection is realized, the coal conveyed by the coal feeding pipe is coal ash, and the coal ash is carried into the furnace by airflow, that is, a 'air-assisted coal conveying' design is adopted.

[0013] The present application has the following advantages:

[0014] 1. The transmission mechanism composed of the transmission wheel and the belt is used, so that the synchronous adjustment of the partition plates is realized, the adjustment lag is reduced, the air inlet and the smoke exhaust can be quickly balanced, the pressure fluctuation of the furnace is reduced, and the stability of the boiler combustion is improved.

[0015] 2. The differential pressure flow meter is combined with the buffer chamber design, and has significant advantages in the measurement of the boiler air volume of the thermal power unit, the expansion structure of the buffer chamber can effectively slow down the direct impact of the high-speed airflow in the boiler on the measuring components, and the reasonable layout of the flow guide baffle can guide the airflow to be smoothly divided, so that the measurement deviation caused by airflow turbulence is avoided.

[0016] 3. The present application integrates air volume detection, pressure detection and temperature abnormal protection functions, when the boiler air volume is lower than the safety threshold, the furnace pressure exceeds the normal range or the temperature of the key part is abnormal, etc. Emergency, the system can trigger the protection action quickly through the optimized thermal protection logic and the fast response mechanism, and through the linkage control of the electromagnetic valve, the partition plate and other executive components, the fuel cut-off and the opening and closing of the ventilation path are completed in a short time, and the further development of the dangerous working condition is timely suppressed.

[0017] 4、The present application realizes comprehensive and accurate detection of air volume by setting flow meters at multiple key positions, adopting independent sampling and signal transmission mode, combining three-point sampling and extended secondary air and hot primary air sampling, and provides reliable basis for accurate adjustment of the boiler. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a schematic diagram of the three-dimensional structure of the present application.

[0019] Figure 2 It is a schematic diagram of the three-dimensional structure of the furnace interior of the present application.

[0020] Figure 3 It is a schematic diagram of the planar structure of the boiler drum, water cooling pipe and superheated pipe of the present application.

[0021] Figure 4 It is a schematic diagram of the three-dimensional structure of the feed hopper, coal inlet pipe and burner of the present application.

[0022] Figure 5 It is a schematic diagram of the three-dimensional structure of the electromagnetic valve, first baffle and first transmission wheel of the present application.

[0023] Figure 6 It is a schematic diagram of the three-dimensional structure of the transmission mechanism of the present application.

[0024] Figure 7 It is a schematic diagram of the three-dimensional structure of the exhaust pipe, second fan and chimney of the present application.

[0025] Figure 8 It is a schematic diagram of the three-dimensional structure of the flow meter of the present application.

[0026] Figure 9 It is a sectional view of the flow meter of the present application.

[0027] In the above drawings: 1 - feed hopper, 2 - furnace, 3 - coal inlet pipe, 4 - exhaust pipe, 5 - burner, 6 - boiler drum, 7 - water cooling pipe, 8 - superheated pipe, 9 - controller, 10 - first fan, 11 - flow meter, 1101 - buffer cavity, 1102 - baffle, 1103 - air inlet pipe, 1104 - detector, 1105 - air outlet pipe, 12 - electromagnetic valve, 13 - first baffle, 14 - first transmission wheel, 15 - second transmission wheel, 16 - third transmission wheel, 17 - second baffle, 18 - fourth transmission wheel, 19 - third baffle, 20 - second fan, 21 - chimney. DETAILED DESCRIPTION

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Example: Boiler air volume sampling, regulation and protection device for thermal power units, such as Figures 1-9 As shown, the system includes a feed hopper 1, a furnace 2, a coal inlet pipe 3, a flue pipe 4, a burner 5, a first fan 10, a solenoid valve 12, a flow meter 11, a first baffle 13, a second baffle 17, and a third baffle 19. The feed hopper 1 is connected to the coal inlet pipe 3 on its side, and the top of the feed hopper 1 is connected to the furnace 2. The burner 5 is installed on the side of the furnace 2, and the flue pipe 4 is installed on the top of the furnace 2. The solenoid valve 12 and the first fan 10 are installed sequentially on the bottom pipe of the feed hopper 1. Flow meters 11 are installed on the cross-sections of the bottom pipe of the feed hopper 1, the coal inlet pipe 3, and the flue pipe 4. The first baffle 13, the second baffle 17, and the third baffle 19 are rotatably connected to these pipes, respectively. A transmission mechanism is installed between the first baffle 13, the second baffle 17, and the third baffle 19 to achieve synchronous angle adjustment.

[0030] like Figure 3 As shown, a boiler drum 6 is installed on the inner wall of the furnace 2. Water-cooled pipes 7 are arranged throughout the inner wall of the furnace 2, and superheated pipes 8 are arranged at the top, forming a complete steam-water circulation loop. The boiler drum 6, as the core component for steam-water separation, can separate the steam-water mixture generated within the furnace 2, ensuring the output of qualified steam. The water-cooled pipes 7, distributed throughout the inner wall of the furnace 2, can fully absorb heat from the furnace 2, reducing the temperature of the inner wall and simultaneously heating the water into a steam-water mixture. The superheated pipes 8, located at the top of the furnace 2, can further heat the saturated steam, making it superheated steam with a certain degree of superheat to meet the unit's power generation needs. The specific circulation path is as follows: the bottom of the boiler drum 6 is connected to the lower connecting pipe of the water-cooled pipes 7, and the upper connecting pipe of the water-cooled pipes 7 is connected to the middle of the boiler drum 6; the saturated steam outlet at the top of the boiler drum 6 is connected to the inlet of the superheated pipes 8, and the outlet of the superheated pipes 8 is connected to the unit's steam turbine through the main steam pipeline (not shown in the figure). Water in boiler drum 6 flows into the lower connecting pipe of water-cooled pipe 7. After absorbing heat from furnace 2 through water-cooled pipe 7, it forms a steam-water mixture, which returns to boiler drum 6 through the upper connecting pipe of water-cooled pipe 7. Boiler drum 6 separates the steam-water mixture. Saturated water remains in boiler drum 6 to continue to participate in the circulation, while saturated steam enters superheated pipe 8 to be heated into superheated steam and then sent to the steam turbine (not shown in the figure).

[0031] like Figure 1As shown, the outer wall of the furnace 2 is provided with a controller 9, which is electrically connected with the flow meter 11 and the electromagnetic valve 12 through the CAN bus. The controller 9 serves as the control core of the whole device, can receive the air volume signal transmitted by the flow meter 11, and issue instructions to the electromagnetic valve 12 and other components according to the preset control logic, so as to realize real-time regulation and control of the boiler operation state. The use of the CAN bus ensures the stability and reliability of signal transmission, makes the information interaction between components more efficient, and provides a guarantee for the precise control of the device.

[0032] As shown in Figure 9 The flow meter 11 includes a buffer chamber 1101, a baffle 1102, an air inlet pipe 1103, an air outlet pipe 1105, and a detector 1104. The buffer chamber 1101 is divided into two unequal volume chambers by the baffle 1102. The air inlet pipe 1103 is in communication with the high-pressure chamber, and the air outlet pipe 1105 is in communication with the low-pressure chamber. The detector 1104 uses a differential pressure transmitter to measure the pressure difference between the two chambers. When the airflow passes through the buffer chamber 1101, the pressure difference between the two chambers can reflect the speed and flow of the airflow. The design of the baffle 1102 can slow down the airflow impact and reduce the influence of airflow disturbance on the measurement results, which helps to stabilize the airflow distribution and improve the stability of the measurement. The differential pressure transmitter can convert the pressure difference signal into a transmissible electrical signal to provide accurate air volume data for the controller 9.

[0033] As shown in Figure 6 The transmission mechanism includes a first transmission wheel 14, a second transmission wheel 15, a third transmission wheel 16, and a fourth transmission wheel 18. The rotating shaft of the first partition plate 13 is rigidly connected with the output shaft of the electromagnetic valve 12 and coaxially fixes the first transmission wheel 14 and the second transmission wheel 15. The rotating shafts of the second partition plate 17 and the third partition plate 19 respectively fix the third transmission wheel 16 and the fourth transmission wheel 18. The first transmission wheel 14 and the third transmission wheel 16 are driven by a belt, and the second transmission wheel 15 and the fourth transmission wheel 18 are driven by a belt, so as to realize synchronous adjustment of the angles of the three partition plates. When the rotating shaft of the first partition plate 13 rotates, it will drive the first transmission wheel 14 and the second transmission wheel 15 to rotate synchronously. Through the transmission action of the belt, the third transmission wheel 16 and the fourth transmission wheel 18 drive the second partition plate 17 and the third partition plate 19 to rotate, respectively. This linkage mode makes the adjustment actions of the three partition plates synchronous, avoids the response delay of individual adjustment of components, can quickly balance the air inlet volume and the exhaust volume, and reduces the pressure fluctuation of the furnace 2.

[0034] As shown in Figure 7As shown, the tail end of the smoke exhaust pipe 4 is sequentially installed with the second fan 20 and the chimney 21. The second fan 20 is controlled by frequency conversion speed regulation, and the second fan 20 can enhance the airflow flow in the smoke exhaust pipe 4 to ensure that the flue gas is smoothly discharged. The chimney 21 guides the discharged flue gas to high altitude to reduce the impact on the surrounding environment. The frequency conversion speed regulation enables the speed of the second fan 20 to be adjusted according to the smoke exhaust condition, thereby ensuring the smoke exhaust effect while reducing energy consumption and improving the economy of the device.

[0035] As shown in Figure 6 The first baffle 13 and the second baffle 17 are initially in a closed state, and the third baffle 19 is initially in an open state. When the first baffle 13 and the second baffle 17 are opened, the third baffle 19 is completely closed, thereby ensuring that, during the starting stage of the device, the coal inlet pipe 3 and the bottom pipeline of the feed hopper 1 can normally intake air and coal, and the smoke exhaust pipe 4 is in a closed state, which is conducive to the ignition and stable combustion in the initial stage of the furnace 2. With the change of the operating state, the angle of each baffle is changed correspondingly through the adjustment of the transmission mechanism to adapt to the air volume demand under different working conditions.

[0036] As shown in Figures 1-2 The flow meter 11 samples at three points of the bottom pipeline of the feed hopper 1, the coal inlet pipe 3 and the smoke exhaust pipe 4 to realize accurate detection. The three-point sampling can comprehensively reflect the air volume conditions of different key parts of the boiler, avoiding the limitations that may exist in single-point sampling. Through comprehensive analysis of the three-point air volume data, the controller 9 can more accurately judge the operating state of the boiler to provide a reliable basis for the issuance of adjustment instructions, thereby improving the accuracy of air volume control. The coal transported by the coal inlet pipe 3 is coal ash, which is carried into the furnace 2 by the airflow primary air. The design of “air-transported coal” is adopted: the airflow in the coal inlet pipe 3 is both the measurement object of the flow meter 11 and the carrier for transporting coal ash. The flow meter 11 on the coal inlet pipe 3 is used to detect the air volume carrying coal ash to ensure that the air volume matches the amount of coal ash. The second baffle 17 controls the air volume by adjusting the sectional area of the airflow passage to further adjust the transportation intensity of the coal ash. The change in the angle of the second baffle 17 only changes the airflow speed and does not directly block the coal ash. When the opening angle increases, the air volume increases and the airflow carrying capacity of the coal ash increases. When the opening angle decreases, the air volume decreases and the transportation intensity decreases, thereby adapting to the demand for coal ash under different loads and ensuring that the coal ash stably enters the furnace 2.

[0037] The air volume sampling process: when the boiler is running, the air flow in the pipeline, through the flow meter 11 for air volume sampling. In the feed hopper 1 bottom pipeline, coal feeding pipe 3, the flow meter 11 of the exhaust pipe 4 work at the same time. After the air flow enters the buffer chamber 1101 of the flow meter 11, it flows through the detector 1104, which measures the pressure difference between the two chambers in real time and converts it into an electrical signal, which is transmitted to the controller 9 through the signal cable. Because the sampling pipeline and signal transmission path of each sampling point are independent of each other, signal interference is effectively avoided, ensuring the accuracy of the measurement data of each sampling point. The controller 9 receives signals from each flow meter 11 to provide basic data for subsequent air volume adjustment.

[0038] Linkage adjustment process; the controller 9 receives the air volume data from each point, and combines the preset control strategy to determine whether the air volume of the current boiler is within a reasonable range. When the air volume needs to be adjusted, the controller 9 sends a command to start the transmission mechanism for adjustment.

[0039] When burning, the controller 9 controls the electromagnetic valve 12 to act, and at the same time drives the rotating shaft of the first baffle 13 to rotate. When the first baffle 13 rotates, the coaxial first transmission wheel 14 and second transmission wheel 15 rotate, and through the belt transmission, the third transmission wheel 16 and fourth transmission wheel 18 drive the second baffle 17 and third baffle 19 to rotate, respectively. At this time, the opening angle of the first baffle 13 and the second baffle 17 increases, the ventilation cross-sectional area of the coal feeding pipe 3 and the bottom pipeline of the feed hopper 1 increases, and the air volume increases; the opening angle of the third baffle 19 decreases, the ventilation cross-sectional area of the exhaust pipe 4 decreases, and the exhaust volume decreases, so as to realize the full combustion of the coal ash in the furnace 2.

[0040] When the exhaust is discharged, the controller 9 drives each component to act in reverse, the first baffle 13 and the second baffle 17 are closed, and the third baffle 19 is opened, which reduces the air volume and increases the exhaust volume. In the whole adjustment process, the controller 9 first makes a preliminary response according to the basic logic stored in itself, and at the same time transmits real-time data to the DCS system, which displays the running state of each component in real time. The operator can intervene through remote monitoring to ensure the stability of the adjustment process.

[0041] Safety protection process: When the device detects abnormal air volume, furnace 2 pressure overrun, temperature anomaly and other conditions, the safety protection mechanism is immediately started. If the air volume of a certain part is lower than the set value too much, or over temperature, over pressure and other conditions occur, the controller 9 reacts quickly according to the preset protection logic, for example, closes the electromagnetic valve 12, cuts off the fuel supply; Adjust the angle of each baffle through the transmission mechanism to change the opening and closing of the ventilation path; Control the fan to adjust the speed, speed up the flue gas exhaust or adjust the air intake to alleviate the abnormal condition. At the same time, the DCS system will send an alarm signal, and the abnormal part and abnormal parameter will be displayed on the monitoring screen to remind the operator to handle it in time. The perfect thermal protection configuration and the coordinated action of each component ensure that the emergency response can be quickly responded to in emergency situations, and the accident risk is minimized.

[0042] Those skilled in the art should understand that the above embodiments do not limit the present application in any form, and any technical solutions obtained by equivalent replacement or equivalent transformation fall within the protection scope of the present application.

Claims

1. A boiler air volume sampling and adjusting protection device for thermal power generating units, a feeding hopper (1), a furnace (2), a coal inlet pipe (3), a smoke exhaust pipe (4), a burner (5), a first fan (10) and a solenoid valve (12), the feeding hopper (1) is connected with the coal inlet pipe (3) at the side, the top of the feeding hopper (1) is communicated with the furnace (2), the furnace (2) is provided with the burner (5) at the side, the top of the furnace (2) is provided with the smoke exhaust pipe (4), the outer wall of the furnace (2) is provided with a controller (9) which is electrically connected with a flowmeter (11) and the solenoid valve (12) through a CAN bus, and the bottom pipe of the feeding hopper (1) is provided with the solenoid valve (12) and the first fan (10) in sequence, characterized in that, Further include flow meter (11), first baffle (13), second baffle (17) and third baffle (19), the bottom end pipe of feed hopper (1), coal inlet pipe (3) and exhaust pipe (4) are all provided with flow meter (11) on cross section, and the first baffle (13), second baffle (17) and third baffle (19) are rotatably connected on these pipes respectively, transmission mechanism is installed between the first baffle (13), second baffle (17) and third baffle (19), transmission mechanism includes first transmission wheel (14), second transmission wheel (15), third transmission wheel (16) and fourth transmission wheel (18), the rotating shaft of first baffle (13) is rigidly connected with the output shaft of electromagnetic valve (12), and coaxially fixed first transmission wheel (14) and second transmission wheel (15), the rotating shaft of second baffle (17) and third baffle (19) is fixed third transmission wheel (16) and fourth transmission wheel (18) respectively, first transmission wheel (14) and third transmission wheel (16) are driven by belt, second transmission wheel (15) and fourth transmission wheel (18) are driven by belt, the angle of three baffles is synchronously adjusted;Flow meter (11) includes buffer cavity (1101), baffle (1102), air inlet pipe (1103), air outlet pipe (1105) and detector (1104), buffer cavity (1101) is divided into two unequal volume chambers by baffle (1102), air inlet pipe (1103) is communicated with high pressure cavity, air outlet pipe (1105) is communicated with low pressure cavity, detector (1104) uses differential pressure transmitter to measure the pressure difference of two chambers.

2. The device for sampling and regulating the air volume of a boiler of a thermal power unit according to claim 1, characterized in that, Further include boiler drum (6), water cooling pipe (7) and superheating pipe (8), boiler drum (6) is installed on the inner wall of furnace (2), water cooling pipe (7) and superheating pipe (8) are arranged in the furnace (2), which forms a complete steam-water circulation loop.

3. The device for sampling and regulating the air volume of a boiler of a thermal power unit according to claim 1, characterized in that, Further include second fan (20) and chimney (21), second fan (20) and chimney (21) are installed in the tail end of exhaust pipe (4) in sequence, second fan (20) uses frequency conversion speed regulation control.

4. The apparatus for sampling and regulating the air volume of a boiler of a thermal power unit according to claim 1, characterized in that, The initial state of first baffle (13) and second baffle (17) is closed, and the initial state of third baffle (19) is opened, when first baffle (13) and second baffle (17) are opened, third baffle (19) is completely closed.

5. The apparatus for sampling and regulating the air volume of a boiler of a thermal power unit according to claim 1, characterized in that, Flow meter (11) is sampled at three points of the bottom end pipe of feed hopper (1), coal inlet pipe (3) and exhaust pipe (4) to realize accurate detection, the coal transported by coal inlet pipe (3) is coal ash, which is carried into furnace (2) by airflow.

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