Thermal power generating unit boiler air volume sampling and adjusting protection device

Abstract

The invention relates to the technical field of thermal power generating unit boilers, in particular to a thermal power generating unit boiler air volume sampling and adjusting protection device which comprises a feed hopper, a hearth and the like. The side face of the feed hopper is connected with a coal inlet pipe, the top end of the feed hopper is communicated with the hearth, and a pipeline at the bottom end of the feed hopper is sequentially provided with an electromagnetic valve and a first fan; flowmeters are arranged on the cross sections of a pipeline at the bottom end of the feeding hopper, the coal feeding pipe and the smoke discharging pipe, a first partition plate, a second partition plate and a third partition plate are rotationally connected to the pipelines respectively, and a transmission mechanism is installed among the first partition plate, the second partition plate and the third partition plate. Through application of a transmission mechanism composed of a transmission wheel and a belt, synchronous adjustment of all the partition plates is achieved, adjustment lag is reduced, the air inlet amount and the smoke exhaust amount can be rapidly balanced, pressure fluctuation of a hearth is reduced, and the combustion stability of the boiler is improved.

Description

Technical Field

[0001] The invention relates to the technical field of thermal power unit boilers, in particular to an air volume sampling and regulating protection device for a thermal power unit boiler. Background Art

[0002] During the operation of thermal power plant boilers, precise control of air volume is key to ensuring combustion efficiency and operational safety. Traditional boiler air volume control methods have many shortcomings. In terms of air volume measurement, the single sampling method and the measurement device's susceptibility to dust interference often lead to large deviations in measurement results, making it difficult to accurately reflect the actual air volume. In the regulation process, the control of the air intake, coal feeding, and smoke exhaust systems is relatively independent, and the responses of each component are asynchronous, resulting in a lag in the balance adjustment of air volume and smoke exhaust volume, which can easily cause furnace pressure fluctuations. Furthermore, the safety protection mechanism is not perfect, lacking multi-parameter coordinated judgment, and there is a risk of false operation or refusal to operate, affecting the stable operation of the unit.

[0003] Therefore, there is an urgent need for a device that can achieve accurate sampling, synchronous adjustment and reliable protection to solve the above problems. Summary of the Invention

[0004] In order to overcome the shortcomings of the existing technology, the technical problem of the present invention is to provide a boiler air volume sampling and regulation protection device for a thermal power unit.

[0005] The technical implementation scheme of the present invention is: a thermal power unit boiler air volume sampling and adjustment protection device, including a feed hopper, a furnace, a coal feed pipe, a smoke exhaust pipe, a burner, a first fan and a solenoid valve. The side of the feed hopper is connected to the coal feed pipe, and the top of the feed hopper is connected to the furnace. The side of the furnace is equipped with a burner, and the top of the furnace is equipped with a smoke exhaust pipe. The solenoid valve and the first fan are installed in sequence on the bottom pipe of the feed hopper. It also includes a flow meter, a first baffle, a second baffle and a third baffle. Flow meters are provided on the cross sections of the bottom pipe of the feed hopper, the coal feed pipe and the smoke exhaust pipe, and the first baffle, the second baffle and the third baffle are respectively rotatably connected to these pipes. A transmission mechanism is installed between the first baffle, the second baffle and the third baffle to achieve synchronous angle adjustment.

[0006] Furthermore, it also includes a boiler drum, water-cooling pipes and superheating pipes. The boiler drum is installed on the inner wall of the furnace, and water-cooling pipes all over the inner wall and superheating pipes on the upper part are arranged inside the furnace to form a complete steam-water circulation loop.

[0007] Furthermore, a controller is also included. The controller is installed on the outer wall of the furnace and is electrically connected to the flow meter and the solenoid valve through a CAN bus.

[0008] Furthermore, the flowmeter includes 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 connected to the high-pressure chamber, and the air outlet pipe is connected to the low-pressure chamber. The detector uses a differential pressure transmitter to measure the pressure difference between the two chambers.

[0009] Furthermore, the transmission mechanism includes a first transmission wheel, a second transmission wheel, a third transmission wheel and a fourth transmission wheel. The rotating shaft of the first partition is rigidly connected to the output shaft of the solenoid valve, and the first transmission wheel and the second transmission wheel are coaxially fixed. The rotating shafts of the second partition and the third partition are respectively fixed to the third transmission wheel and the fourth transmission wheel. The first transmission wheel and the third transmission wheel are driven by a belt, and the second transmission wheel and the fourth transmission wheel are driven by a belt to realize synchronous angle adjustment of the three partitions.

[0010] Furthermore, it also includes a second fan and a chimney. The second fan and the chimney are installed in sequence at the tail end of the smoke exhaust pipe, and the second fan adopts variable frequency speed control.

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

[0012] Furthermore, the flow meter takes samples at three points: the pipe at the bottom of the feed hopper, the coal inlet pipe, and the smoke exhaust pipe to achieve accurate detection. The coal transported by the coal inlet pipe is coal ash, which is carried into the furnace by the airflow, that is, the "air-blown coal transportation" design is adopted.

[0013] The beneficial effects of the present invention are: 1. The present invention realizes synchronous adjustment of each partition through the application of a transmission mechanism consisting of a transmission wheel and a belt, reduces adjustment lag, can quickly balance the air intake and exhaust volume, reduce furnace pressure fluctuations, and improve boiler combustion stability.

[0014] 2. The differential pressure flowmeter combined with the buffer chamber design adopted in the present invention shows significant advantages in measuring the air volume of thermal power unit boilers. The expansion structure of the buffer chamber can effectively reduce the direct impact of the high-speed airflow in the boiler on the measuring components. At the same time, combined with the reasonable layout of the guide baffle, it can guide the airflow to be smoothly diverted, avoiding measurement deviations caused by airflow turbulence.

[0015] 3. The present invention integrates air volume detection, pressure detection and temperature anomaly protection functions. When an emergency occurs in the boiler, such as the air volume falling below the safety threshold, the furnace pressure exceeding the normal range or the temperature of key parts being abnormal, the system can quickly trigger the protection action by relying on the optimized thermal protection logic and rapid response mechanism. By controlling the solenoid valve, partition and other actuators in a linked manner, the system can complete the fuel cut-off and the opening and closing of the ventilation path in a short time, and promptly curb the further development of dangerous working conditions.

[0016] 4. The present invention achieves comprehensive and accurate detection of air volume by setting flow meters at multiple key locations, adopting independent sampling and signal transmission methods, combining three-point sampling and extended secondary air and hot primary air sampling, and providing a reliable basis for accurate adjustment of the boiler. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention.

[0018] Figure 2 It is a schematic diagram of the three-dimensional structure inside the furnace of the present invention.

[0019] Figure 3 It is a schematic diagram of the planar structure of the boiler drum, water-cooling tube and superheating tube of the present invention.

[0020] Figure 4 It is a schematic diagram of the three-dimensional structure of the feed hopper, coal feed pipe and burner of the present invention.

[0021] Figure 5 It is a schematic diagram of the three-dimensional structure of the solenoid valve, the first partition plate and the first transmission wheel of the present invention.

[0022] Figure 6 It is a schematic diagram of the three-dimensional structure of the transmission mechanism of the present invention.

[0023] Figure 7 It is a schematic diagram of the three-dimensional structure of the smoke exhaust pipe, the second fan and the chimney of the present invention.

[0024] Figure 8 It is a schematic diagram of the three-dimensional structure of the flow meter of the present invention.

[0025] Figure 9 It is a cross-sectional view of the flow meter of the present invention.

[0026] In the above drawings: 1-feed hopper, 2-furnace, 3-coal inlet pipe, 4-smoke exhaust pipe, 5-burner, 6-boiler drum, 7-water cooling pipe, 8-superheating pipe, 9-controller, 10-first fan, 11-flow meter, 1101-buffer chamber, 1102-baffle, 1103-air inlet pipe, 1104-detector, 1105-air outlet pipe, 12-solenoid valve, 13-first partition, 14-first transmission wheel, 15-second transmission wheel, 16-third transmission wheel, 17-second partition, 18-fourth transmission wheel, 19-third partition, 20-second fan, 21-chimney. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0028] Example: Thermal power unit boiler air volume sampling and regulation protection device, such as Figures 1-9 As shown, a feed hopper 1, a furnace 2, a coal feed pipe 3, a smoke exhaust 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 side of the feed hopper 1 is connected to the coal feed pipe 3, the top of the feed hopper 1 is connected to the furnace 2, the side of the furnace 2 is installed with a burner 5, the top of the furnace 2 is installed with an exhaust pipe 4, the bottom pipe of the feed hopper 1 is installed with a solenoid valve 12 and a first fan 10 in sequence, the cross section of the bottom pipe of the feed hopper 1, the coal feed pipe 3 and the exhaust pipe 4 are all provided with a flow meter 11, and these pipes are respectively rotatably connected with the first baffle 13, the second baffle 17 and the third baffle 19, and a transmission mechanism is installed between the first baffle 13, the second baffle 17 and the third baffle 19 to achieve synchronous angle adjustment.

[0029] like Figure 3 As shown, a boiler drum 6 is installed on the inner wall of the furnace 2. Inside the furnace 2, water-cooling pipes 7 are arranged throughout the inner wall, and superheating pipes 8 are arranged at the top, forming a complete steam-water circulation loop. The boiler drum 6, as the core component of the steam-water separation, can separate the steam-water mixture generated in the furnace 2 to ensure the output of qualified steam. The water-cooling pipes 7 are distributed throughout the inner wall of the furnace 2, fully absorbing the heat within the furnace 2, reducing the temperature of the inner wall of the furnace 2, and simultaneously heating the water into a steam-water mixture. The superheating pipes 8 are located at the top of the furnace 2 and can further heat the saturated steam to superheated steam with a certain degree of superheat to meet the power generation requirements of the unit. The specific circulation path is as follows: the bottom of the boiler drum 6 is connected to the lower connecting pipe of the water-cooling pipe 7, and the upper connecting pipe of the water-cooling pipe 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 superheating pipe 8. The outlet of the superheating pipe 8 is connected to the unit's steam turbine through the main steam pipeline (not shown). The water in the boiler drum 6 flows into the lower connecting pipe of the water-cooling pipe 7, absorbs the heat in the furnace 2 through the water-cooling pipe 7 to form a steam-water mixture, and returns to the boiler drum 6 through the upper connecting pipe of the water-cooling pipe 7; the boiler drum 6 separates the steam-water mixture, and the saturated water remains in the boiler drum 6 to continue to participate in the circulation. The saturated steam enters the superheating pipe 8, is heated to superheated steam, and is then transported to the steam turbine (not shown in the figure).

[0030] like Figure 1As shown, a controller 9 is mounted on the outer wall of furnace 2 and electrically connected to a flowmeter 11 and solenoid valve 12 via a CAN bus. As the control core of the entire device, controller 9 receives air volume signals from flowmeter 11 and, based on pre-set control logic, issues commands to actuators such as solenoid valve 12, enabling real-time regulation of the boiler's operating status. The use of the CAN bus ensures stable and reliable signal transmission, making information exchange between components more efficient and ensuring precise control of the device.

[0031] like Figure 9 As shown, 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 connected to the high-pressure chamber, and the air outlet pipe 1105 is connected to the low-pressure chamber. The detector 1104 uses a differential pressure transmitter to measure the pressure difference between the two chambers. When the air flow passes through the buffer chamber 1101, the pressure difference formed between the two chambers can reflect the speed and flow of the air flow. The design of the baffle 1102 can slow down the air flow impact, reduce the impact of air flow disturbance on the measurement results, help to stabilize the air flow diversion, and improve the measurement stability. The differential pressure transmitter can convert the pressure difference signal into a transmittable electrical signal to provide accurate air volume data for the controller 9.

[0032] like Figure 6 As shown, 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 13 is rigidly connected to the output shaft of the solenoid valve 12, and the first transmission wheel 14 and the second transmission wheel 15 are coaxially fixed. The rotating shafts of the second partition 17 and the third partition 19 are respectively fixed to 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 that the angles of the three partitions can be adjusted synchronously. When the rotating shaft of the first partition 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 respectively drive the second partition 17 and the third partition 19 to rotate. This linkage method ensures that the adjustment action of the three partitions remains synchronized, avoiding the response delay when each component is adjusted separately, and can quickly achieve a balance between the air intake and the smoke exhaust volume, reducing the pressure fluctuation of the furnace 2.

[0033] like Figure 7As shown, a second fan 20 and a chimney 21 are installed in sequence at the tail end of the smoke exhaust pipe 4. The second fan 20 adopts variable frequency speed control. The second fan 20 can enhance the airflow in the smoke exhaust pipe 4 to ensure smooth exhaust of smoke; the chimney 21 guides the exhausted smoke to high altitude to reduce the impact on the surrounding environment. The variable frequency speed control enables the rotation speed of the second fan 20 to be adjusted according to the smoke exhaust situation, while ensuring the smoke exhaust effect, reducing energy consumption and improving the economy of the device.

[0034] like Figure 6 As shown, the first partition 13 and the second partition 17 are initially in a closed state, and the third partition 19 is initially in an open state. When the first partition 13 and the second partition 17 are opened, the third partition 19 is completely closed, ensuring that during the startup phase of the device, the coal inlet pipe 3 and the pipe at the bottom end of the feed hopper 1 can normally intake air and coal, while the smoke exhaust pipe 4 is in a closed state, which is beneficial to the ignition in the furnace 2 and the stability of the initial combustion. As the operating state changes, the angle of each partition changes accordingly through the adjustment of the transmission mechanism to adapt to the air volume requirements under different working conditions.

[0035] like Figure 1-Figure 2 As shown, the flowmeter 11 takes samples at three points: the bottom pipe of the feed hopper 1, the coal inlet pipe 3, and the smoke exhaust pipe 4, to achieve precise detection. Three-point sampling can comprehensively reflect the air volume conditions at different key parts of the boiler, avoiding the limitations that may exist with single-point sampling. Through comprehensive analysis of the air volume data at these three points, the controller 9 can more accurately determine the operating status of the boiler, providing a reliable basis for issuing 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 primary air flow. A "wind-driven coal transportation" design is adopted: the airflow within the coal inlet pipe 3 is both the measurement object of the flowmeter 11 and the carrier for transporting the 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 partition 17 controls the air volume by adjusting the cross-sectional area of ​​the air flow channel, and then adjusts the conveying force of the coal ash. The angle change only changes the air flow speed and does not directly block the coal ash - when the opening angle increases, the air volume increases and the ability of the airflow to carry coal ash is enhanced; when the opening angle decreases, the air volume decreases and the conveying force weakens, adapting to the coal ash demand under different loads to ensure that the coal ash enters the furnace 2 stably.

[0036] Air volume sampling process: When the boiler is running, the air flow flows in each pipe, and the air volume sampling is carried out through the flow meter 11. The flow meters 11 in the bottom pipe of the feed hopper 1, the coal inlet pipe 3, and the smoke exhaust pipe 4 work simultaneously. After the air flow enters the buffer chamber 1101 of the flow meter 11, it flows through the detector 1104. The detector 1104 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. Since the sampling pipelines and signal transmission paths 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 and provides basic data for subsequent air volume adjustment.

[0037] Linkage adjustment process: The controller 9 determines whether the current boiler air volume is within a reasonable range based on the received air volume data at each point and the preset control strategy. When the air volume needs to be adjusted, the controller 9 issues a command to start the transmission mechanism for adjustment.

[0038] During combustion, controller 9 activates solenoid valve 12, simultaneously driving the shaft of first baffle 13 to rotate. As first baffle 13 rotates, the coaxial first and second drive wheels 14, 15 rotate accordingly. Through belt drive, third and fourth drive wheels 16, 18 respectively drive the second and third baffles 17, 19. At this point, the opening angles of first and second baffles 13, 17 increase, increasing the ventilation cross-sectional area of ​​the coal inlet pipe 3 and the pipe at the bottom of the feed hopper 1, thereby increasing the air intake. The opening angle of third baffle 19 decreases, reducing the ventilation cross-sectional area of ​​the smoke exhaust pipe 4 and the amount of smoke exhaust, thereby ensuring full combustion of the coal ash within furnace 2.

[0039] During smoke exhaust, controller 9 drives each component in reverse, closing first and second baffles 13, 17 and opening third baffle 19, reducing air intake and increasing exhaust. Throughout the adjustment process, controller 9 first responds based on its stored basic logic and simultaneously transmits real-time data to the DCS system. The DCS system displays the operating status of each component in real time, allowing operators to intervene through remote monitoring to ensure stable adjustment.

[0040] Safety protection process: When the device detects abnormal air volume, excessive furnace 2 pressure, abnormal temperature, etc., the safety protection mechanism is immediately activated. If the air volume of a certain part is much lower than the set value, or if overtemperature or overpressure occurs, the controller 9 will respond quickly according to the preset protection logic. For example, it will close the solenoid valve 12 to cut off the fuel supply; adjust the angle of each partition through the transmission mechanism to change the opening and closing of the ventilation path; control the fan to adjust the speed, speed up the exhaust of smoke or adjust the air intake to alleviate the abnormal situation. At the same time, the DCS system will issue an alarm signal and display the abnormal part and abnormal parameters on the monitoring screen to remind the operator to deal with it in time. The perfect thermal protection configuration and the coordinated action of various components ensure a quick response in emergency situations and minimize the risk of accidents.

[0041] Those skilled in the art should understand that the above embodiments do not limit the present invention in any form, and any technical solutions obtained by equivalent replacement or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A thermal power unit boiler air volume sampling and regulating protection device, comprising a feed hopper (1), a furnace (2), a coal feed pipe (3), a smoke exhaust pipe (4), a burner (5), a first fan (10) and a solenoid valve (12), wherein the side of the feed hopper (1) is connected to the coal feed pipe (3), the top of the feed hopper (1) is connected to the furnace (2), the side of the furnace (2) is provided with a burner (5), the top of the furnace (2) is provided with a smoke exhaust pipe (4), and the bottom pipe of the feed hopper (1) is provided with a solenoid valve (12) and a first fan (10) in sequence, wherein: The invention also includes a flow meter (11), a first partition (13), a second partition (17) and a third partition (19). The flow meter (11) is provided on the cross section of the bottom end pipe of the feed hopper (1), the coal feed pipe (3) and the smoke exhaust pipe (4). The first partition (13), the second partition (17) and the third partition (19) are rotatably connected to these pipes respectively. A transmission mechanism is installed between the first partition (13), the second partition (17) and the third partition (19) to achieve synchronous angle adjustment.

2. The device for sampling and regulating air flow for a thermal power plant boiler according to claim 1, characterized in that: The furnace (2) further comprises a boiler drum (6), a water-cooling pipe (7) and a superheating pipe (8). The boiler drum (6) is installed on the inner wall of the furnace (2), and the water-cooling pipe (7) distributed throughout the inner wall and the superheating pipe (8) on the upper part are arranged inside the furnace (2), forming a complete steam-water circulation loop.

3. The device for sampling and regulating air flow for a thermal power plant boiler according to claim 2, characterized in that: The furnace (2) further comprises a controller (9), which is mounted on the outer wall of the furnace (2) and is electrically connected to the flow meter (11) and the solenoid valve (12) via a CAN bus.

4. The device for sampling and regulating air flow for a thermal power plant boiler according to claim 3 is characterized in that: The flow meter (11) comprises 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 connected to the high-pressure chamber, and the air outlet pipe (1105) is connected to the low-pressure chamber. The detector (1104) uses a differential pressure transmitter to measure the pressure difference between the two chambers.

5. The device for sampling and regulating air flow for a thermal power plant boiler according to claim 4, characterized in that: 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 (13) is rigidly connected to the output shaft of the solenoid valve (12), and the first transmission wheel (14) and the second transmission wheel (15) are coaxially fixed. The rotating shafts of the second partition (17) and the third partition (19) are respectively fixed to 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 that the angles of the three partitions are synchronously adjusted.

6. The device for sampling and regulating air flow for a boiler of a thermal power plant according to claim 5, characterized in that: The second fan (20) and the chimney (21) are also included. The second fan (20) and the chimney (21) are sequentially installed at the tail end of the smoke exhaust pipe (4). The second fan (20) adopts variable frequency speed control.

7. The device for sampling and regulating air flow for a thermal power plant boiler according to claim 6, characterized in that: The first partition (13) and the second partition (17) are initially in a closed state, and the third partition (19) is initially in an open state. When the first partition (13) and the second partition (17) are opened, the third partition (19) is completely closed.

8. The device for sampling and regulating air flow for a boiler of a thermal power plant according to claim 7, characterized in that: The flow meter (11) takes samples at three points: the bottom pipe of the feed hopper (1), the coal inlet pipe (3), and the smoke exhaust pipe (4) to achieve accurate detection. The coal transported by the coal inlet pipe (3) is coal ash, which is carried into the furnace (2) by the air flow.

Images