Hearth negative pressure control system for boiler coke falling working condition

Abstract

The invention provides a hearth negative pressure control system under a boiler coke falling working condition. The hearth negative pressure control system comprises a boiler and a main induced draft fan communicated with the boiler through a flue, and a water cooling wall of the boiler is connected with a vibration measuring device, a hearth negative pressure measuring device and a negative pressure adjusting device; the vibration measuring device comprises expansion recorders installed at the four corners of a water cooling wall of the boiler, each expansion recorder is provided with a vibration measuring point, and the vibration measuring points are used for monitoring the vibration value of the boiler bottom when coke falls off from the inner wall of the boiler. The hearth negative pressure measuring device comprises a pressure transmitter and a pressure switch controller, the pressure transmitter is used for sensing the real-time pressure in the boiler, and when the real-time pressure reaches a negative pressure threshold value, the pressure switch controller is used for turning off the negative pressure adjusting device; the negative pressure adjusting device comprises a main control unit, and the main control unit is used for adaptively adjusting the induced air volume of the main induced draft fan according to the vibration value obtained by the vibration measuring point. The system solves a series of problems that the boiler is unstable in operation and easy to extinguish during power generation of an existing thermal power plant.

Description

Technical Field

[0001] The present invention relates to the technical field of boiler control, and in particular to a furnace negative pressure control system for a boiler under a coking condition. Background Art

[0002] A thermal power plant, also known as a thermal power plant, is a factory that uses combustibles (such as coal) as fuel to produce electricity. Its basic production process is: when the fuel burns, it heats water to generate steam, converting the chemical energy of the fuel into thermal energy. The steam pressure drives the turbine to rotate, converting the thermal energy into mechanical energy, and then the turbine drives the generator to rotate, converting the mechanical energy into electrical energy.

[0003] At present, with the depth adjustment of coal blending, the coal quality entering the thermal power generation boiler has deviated far from the designed coal type, resulting in serious coking of the boiler and frequent boiler coking and fire extinguishing. When the boiler cokes, the negative pressure in the furnace basically shows a negative trend at first and then a positive trend. In addition, due to the cooling of the coke blocks, a large amount of steam is generated. The peak positive pressure in the furnace is greater than the peak negative pressure. According to the current induced draft impeller adjustment logic, the adjustment action is not started until the furnace has reached the peak positive pressure. The positive pressure peak is not adjusted in time to suppress the peak positive pressure, resulting in frequent boiler coking and fire extinguishing. Therefore, the present application provides a furnace negative pressure control system for boiler coking conditions to meet the stable operation requirements of coal-fired boilers. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a furnace negative pressure control system for boiler coking conditions, so as to solve a series of problems such as unstable operation and easy extinguishing of boilers during power generation in existing thermal power plants.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A furnace negative pressure control system for a boiler under a coke-dropping condition comprises a boiler and a main induced draft fan connected to the boiler through a flue, wherein the key is that: a vibration measuring device, a furnace negative pressure measuring device and a negative pressure regulating device are connected to the water-cooled wall of the boiler; the vibration measuring device comprises expansion recorders installed at the four corners of the boiler water-cooled wall, each of the expansion recorders is provided with a vibration measuring point, and the vibration measuring point is used to monitor the vibration value of the furnace bottom when the inner wall of the boiler drops coke; the furnace negative pressure measuring device comprises a pressure transmitter and a pressure switch controller, the pressure transmitter is used to sense the real-time pressure in the boiler through a sampling port, and when the real-time pressure reaches a negative pressure threshold, the negative pressure regulating device is shut down by the pressure switch controller; the negative pressure regulating device comprises a main control unit, which is connected to the vibration signal acquisition circuit of the expansion recorder on the one hand, and is connected to the control circuit of the main induced draft fan on the other hand, so as to adaptively adjust the induced air volume of the main induced draft fan according to the vibration value obtained by the vibration measuring point.

[0007] Preferably, a bypass interface is provided on the boiler, and the bypass interface is connected to a bypass induced draft fan through a bypass negative pressure pipe. A slag hopper for collecting coal slag is provided at the bottom of the boiler. The bottom end of the boiler is also provided with a trigger component for controlling the operating power of the bypass induced draft fan when coke is dropped from the inner wall of the boiler. The trigger component includes a plurality of groups of sliding rheostats and rubber pads with corresponding positions, and the sliding rheostats and the bypass induced draft fan are located in the same series circuit; when the rubber pad is hit by coke drop on the inner wall of the boiler, it can synchronously drive the sliding vane on the corresponding sliding rheostat to move, so as to increase the induced air volume of the bypass induced draft fan, thereby cooperating with the main induced draft fan to adjust the boiler pressure.

[0008] Preferably, the slag hopper is coaxially arranged with the boiler, and one end of the slag hopper is conically arranged, and a collecting trough for collecting coal slag is also provided in the slag hopper.

[0009] Preferably, the boiler is further provided with a central tube, wherein a section of the central tube is located inside the boiler and in the middle of the boiler, and both ends of the central tube penetrate through the boiler and extend to the outside of the boiler.

[0010] Preferably, a spiral tube is further provided in the boiler, the spiral tube is close to the inner wall of the boiler, and both ends of the spiral tube pass through the boiler and extend to the outside of the boiler, the center tube and both ends of the spiral tube are connected to the external water channel, and after the boiler is operated, the center tube and the spiral tube are both subjected to heating treatment.

[0011] Preferably, a plurality of evenly distributed mounting seats are fixedly mounted on the outer wall of the boiler, a plurality of the sliding rheostats are respectively mounted on the corresponding mounting seats, and the slide vane is slidably mounted on the corresponding sliding rheostat and is used to control the change in resistance value of the sliding rheostat, and the plurality of the sliding rheostats are all located in the same series circuit with the bypass draft fan.

[0012] Preferably, a fixing ring is fixedly sleeved on the inner wall of the boiler, and a plurality of groups of vertical guide rods are slidably sleeved on the fixing ring, and the top ends of two vertical guide rods at the same relative position are fixedly connected to the same rubber pad.

[0013] Preferably, the rubber pad is arranged in an arc surface and is adapted to the position of the collecting trough.

[0014] Preferably, a fixing plate is fixedly sleeved on the bottom end of the vertical guide rod, and a spring is sleeved on the vertical guide rod, and two ends of the spring are respectively connected to the fixing ring and the corresponding fixing plate.

[0015] Preferably, an arc-shaped connecting rod is also sleeved on the same group of vertical guide rods, and a connecting block is connected to the arc-shaped connecting rod. A plurality of vertical slide grooves are opened on the outer wall of the boiler, and the connecting block is slidably clamped in the corresponding vertical slide grooves, and insulating sheets are installed on both sides of the connecting block, and a limiting strip adapted to the corresponding slide is installed on one side of the insulating sheet, and the slide is clamped between the insulating sheets of the corresponding group through the limiting strip, and bolts are also threadedly sleeved on the insulating sheets of the same group, and the bolts pass through the corresponding slide.

[0016] Compared with the prior art, the present invention has at least the following significant effects:

[0017] (1) In the above scheme, after judging the boiler coke-dropping conditions, the main induced draft fan moving blade rapid adjustment system is introduced to make the high negative pressure in the furnace disappear as soon as possible, thereby preventing the fire from being extinguished due to the high furnace pressure II value when the boiler cokes, and improving the stability of the power generation boiler in the thermal power plant during operation.

[0018] (2) The falling coal slag impacts the rubber pad below, which in turn drives the corresponding slider to slide on the corresponding sliding rheostat, thereby changing the operating power of the entire bypass induced draft fan. As the coke is dropped, the suction strength of the bypass induced draft fan is changed synchronously. At the moment when the coal slag falls, the negative pressure strength in the boiler is adjusted accordingly, thereby further ensuring the stability of the gas pressure in the boiler and optimizing the stability of the boiler.

[0019] (3) By arranging central tubes and spiral tubes of different layouts inside the boiler, more water can be fully heated by the coal flame when the boiler is running, thereby increasing the steam content and temperature per unit time and improving the efficiency of thermal power generation.

[0020] (4) By fixing multiple evenly distributed mounting seats on the inner wall of the boiler, the sliding rheostats can be evenly distributed on the outer wall of the boiler, eliminating dead corners for slag falling and ensuring more accurate and even adjustment of the operating power of the bypass induced draft fan. This evenly distributed sliding rheostat design can effectively avoid uneven temperature of the inner wall of the boiler caused by local pressure changes, thereby reducing thermal stress concentration and extending the service life of the boiler.

[0021] (5) By sleeve-fitting the fixing ring and vertical guide rod on the inner wall of the boiler, the rubber pad can more flexibly drive the sliding vane to move when it is impacted by coke drop, thereby realizing rapid adjustment of the bypass induced draft fan power. This design not only improves the response speed of the system, but also effectively reduces the pressure fluctuation in the boiler caused by coke drop, ensuring the stability of boiler operation.

[0022] (6) By opening multiple vertical slide grooves on the outer wall of the boiler and installing insulating sheets and limit strips on the connecting blocks, the movement of the slider on the sliding rheostat can be ensured to be more stable and reliable. This design not only improves the stability of the system, but also effectively prevents system failures caused by slider jamming or poor sliding, further improving the safety of boiler operation.

[0023] In summary, the present invention, through a series of innovative designs, not only improves the stability, safety and thermal efficiency of boiler operation, but also effectively extends the service life of the boiler, providing a more efficient, stable and safe boiler operation solution for thermal power plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which are incorporated herein and constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, further serve to explain the principles of the present disclosure and to enable those skilled in the relevant art to make and use the present disclosure.

[0025] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0026] Figure 2 It is a schematic diagram of a partial three-dimensional structure of the present invention;

[0027] Figure 3 This is a schematic diagram of the cutaway three-dimensional structure of the boiler of the present invention;

[0028] Figure 4 It is a schematic diagram of the three-dimensional structure of the boiler of the present invention after the spiral tube is removed;

[0029] Figure 5 This is a schematic diagram of the three-dimensional structure of the slag bucket of the present invention;

[0030] Figure 6 It is a schematic diagram of the three-dimensional structure of the boiler of the present invention from top view;

[0031] Figure 7 It is a schematic diagram of a partially cutaway three-dimensional structure of the boiler of the present invention;

[0032] Figure 8 It is a schematic diagram of the three-dimensional structure of the trigger component of the present invention;

[0033] Fig. 9 It is a schematic diagram of the disassembled structure of the sliding rheostat and the trigger component of the present invention.

[0034] [reference numerals]

[0035] 1. Boiler; 2. Slag hopper; 3. Bypass interface; 4. Bypass induced draft fan; 5. Bypass negative pressure pipe; 6. Spiral pipe; 7. Center pipe; 8. Collecting tank; 9. Sliding rheostat; 10. Rubber pad; 11. Fixed ring; 12. Vertical guide rod; 13. Fixed plate; 14. Spring; 15. Connecting block; 16. Vertical slide groove; 17. Sliding plate; 18. Insulating sheet; 19. Limiting strip; 20. Bolt; 21. Connecting end.

[0036] As shown in the figure, in order to clearly implement the structure of the embodiment of the present invention, specific structures and devices are marked in the figure, but this is only for illustrative purposes and is not intended to limit the present invention to the specific structure, device and environment. According to specific needs, ordinary technicians in this field can adjust or modify these devices and environments, and the adjustments or modifications made are still included in the scope of the attached claims. DETAILED DESCRIPTION

[0037] The following is a detailed description of a furnace negative pressure control system for boiler coke-dropping conditions provided by the present invention in conjunction with the accompanying drawings and specific embodiments. At the same time, it is explained here that in order to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and those skilled in the art may also adopt other alternative methods to implement some known technologies; and the accompanying drawings are only for a more specific description of the embodiments, and are not intended to specifically limit the present invention.

[0038] It should be noted that the references to "one embodiment", "an embodiment", "an exemplary embodiment", "some embodiments" and the like in the specification indicate that the embodiments described may include specific features, structures or characteristics, but not every embodiment may include the specific features, structures or characteristics. In addition, when a specific feature, structure or characteristic is described in conjunction with an embodiment, it should be within the knowledge of a person skilled in the art to implement such feature, structure or characteristic in conjunction with other embodiments (whether or not explicitly described).

[0039] In general, a term can be understood, at least in part, from its use in context. For example, depending, at least in part, on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in the singular sense, or can be used to describe a combination of features, structures, or characteristics in the plural sense. Additionally, the term "based on" can be understood as not necessarily intended to convey an exclusive set of factors, but can instead, depending, at least in part, on the context, allow for the presence of other factors that are not necessarily explicitly described.

[0040] It will be understood that the meaning of “on,” “over,” and “above” in this disclosure should be interpreted in the broadest manner, so that “on” means not only “directly on” something, but also includes the meaning of being “on” something with intervening features or layers therebetween, and “on” or “over” means not only “on” or “above” something, but also includes the meaning of being “on” or “above” something with no intervening features or layers therebetween.

[0041] Additionally, spatially relative terms such as "under," "beneath," "lower," "above," "upper," and the like may be used herein for descriptive convenience to describe the relationship of one element or feature to another element or features, as shown in the accompanying drawings. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the accompanying drawings. The device may be oriented in other ways, and the spatially relative descriptors used herein may be similarly interpreted accordingly.

[0042] like Figure 1-9 As shown, an embodiment of the present invention provides a furnace negative pressure control system for a boiler under a coke-dropping condition, comprising a boiler 1 and a main induced draft fan connected to the boiler through a flue, wherein a vibration measuring device, a furnace negative pressure measuring device and a negative pressure regulating device are connected to the water-cooled wall of the boiler 1; the vibration measuring device comprises expansion recorders installed at the four corners of the boiler water-cooled wall, each of the expansion recorders is provided with a vibration measuring point, and the vibration measuring point is used to monitor the vibration value of the furnace bottom when the inner wall of the boiler drops coke; the furnace negative pressure measuring device comprises a pressure transmitter and a pressure switch controller, the pressure transmitter is used to sense the real-time pressure in the boiler through a sampling port, and when the real-time pressure reaches the negative pressure threshold, the negative pressure regulating device is shut down by the pressure switch controller; the negative pressure regulating device comprises a main control unit, which is connected to the vibration signal acquisition circuit of the expansion recorder on the one hand, and is connected to the control circuit of the main induced draft fan on the other hand, so as to adaptively adjust the induced air volume of the main induced draft fan according to the vibration value obtained by the vibration measuring point.

[0043] In specific implementation, a bypass interface 3 is provided on the boiler, and the bypass interface 3 is connected to the bypass induced draft fan 4 through a bypass negative pressure pipe 5. A slag hopper 2 for collecting coal slag is provided at the bottom of the boiler 1. The bottom end of the boiler 1 is also provided with a trigger component for correspondingly controlling the operating power of the bypass induced draft fan 4 when the inner wall of the boiler 1 is de-coked. The trigger component includes a plurality of groups of sliding rheostats 9 and rubber pads 10 with corresponding positions. The sliding rheostats 9 and the bypass induced draft fan 4 are located in the same series circuit; when the rubber pad 10 is hit by the de-coked inner wall of the boiler, it can synchronously drive the sliding vane on the corresponding sliding rheostat 9 to move, so as to increase the induced air volume of the bypass induced draft fan 4, thereby cooperating with the main induced draft fan to adjust the boiler pressure.

[0044] When the boiler is de-coking, the negative pressure in the furnace fluctuates greatly, basically showing a negative first and then positive state. In extreme cases, it will trigger a high negative pressure in the furnace and cause the boiler to extinguish. The main reason for the positive negative pressure in the furnace is that after the coal is mixed and burned, coal with unqualified ash melting point often enters the furnace, causing the boiler to aggravate coking. After the coke blocks produced fall into the slag bucket 2, a large amount of water vapor evaporates instantly. A large amount of water vapor rushes into the furnace in a short time. Because the volume of the furnace itself is relatively small, the negative pressure in the furnace increases a lot. By consulting the historical curve, the previous boiler de-coking fire extinguishing events are analyzed. The furnace maintains a negative pressure state for 4s to 5s, and then the furnace pressure quickly rises to a positive pressure state, and the maintenance time is relatively long. The main reason is that the induced draft fan is adjusted slowly during the boiler de-coking process. In order to avoid the occurrence of boiler de-coking fire extinguishing events, it is necessary to optimize the furnace negative pressure regulation system under the boiler de-coking condition. The present invention judges the boiler de-coking condition in advance, introduces the main induced draft fan fast adjustment loop logic, and timely suppresses the peak value and peak time of the furnace positive pressure, thereby reducing the occurrence of boiler de-coking fire extinguishing.

[0045] Taking the 6*350WM unit as an example, four vibration measuring points are installed on the expansion recorder at the four corners of the bottom of the furnace water-cooled wall to monitor the vibration value of the bottom of the water-cooled wall when coking. According to the vibration values ​​measured by the four corner vibration measuring points, the coking position and amount can be determined. Through the analysis and judgment of the vibration data of the experimental data, the water-cooled wall vibration measuring points can accurately reflect the coking situation of the boiler;

[0046] The water-cooled wall vibration measurement point has two characteristics:

[0047] 1) Strong anti-interference ability: only boiler coking can cause the vibration measurement value to change, and other disturbances will not cause the vibration measurement value to change;

[0048] 2) The changes of the vibration measurement point and the furnace pressure measurement point are sequential and synchronized: after the boiler loses coke, the vibration measurement value always increases first, and then the furnace pressure maintains negative pressure for 3 to 4 seconds, and then the furnace pressure quickly becomes positive and reaches the highest value;

[0049] When the boiler loses coke, the negative pressure in the furnace is first negative and then positive. According to historical data statistics, the lowest negative pressure each time exceeds -500pa, but the negative pressure is maintained for a short time. At this time, the main induced draft impeller is still adjusted according to the original logic circuit; when the furnace pressure begins to rise, a set of negative pressure fast adjustment circuit is added to make the main induced draft impeller quickly adjusted to avoid the high furnace pressure triggering MFT action (MFT generally refers to the automatic protection measures for equipment during boiler operation: when an abnormal accident occurs, it will alarm or automatically stop the equipment operation, keep the supply and induced draft fans running, and perform purging. When the equipment needs to be started after the defect or fault is eliminated, the MFT must be reset before the equipment can be started, otherwise the motor equipment cannot be started. The role of MFT is to continuously monitor whether various predetermined safe operating conditions are met. Once a condition that may endanger the safe operation of the boiler occurs, the fuel entering the furnace will be quickly cut off to avoid accidents). The specific technical improvement plan is as follows:

[0050] 1) Specific judgment conditions for boiler coke-dropping conditions: when one of the four water-cooled wall vibration measurement points reaches 6mm / s or more within 1 minute, it is judged that the negative pressure signal quickly turns negative first and then positive, and the change rate of positive and negative items exceeds 100Pa / s, and the negative direction is less than -500Pa, and then the furnace pressure rises rapidly (100Pa / s); or when one of the four water-cooled wall vibration measurement points reaches 6mm / s or more within 1 minute, any furnace negative pressure high II value action occurs;

[0051] 2) Control logic:

[0052] a. When the above conditions are met, the two main induced draft fan impeller instructions will be increased by 5% of the feedforward signal, and then the main induced draft fan impellers will still be adjusted according to the current furnace negative pressure value;

[0053] b. Within 1 minute after the above judgment conditions are met, after the furnace negative pressure returns from the positive peak, the negative pressure drop rate exceeds 50Pa / s or any furnace pressure low action is performed, and the feedforward signal is released at a rate of 1% / s;

[0054] c. To prevent the fan from surging due to large fluctuations in negative pressure when the boiler is de-coked, the upper limit of the command for the main induced draft fan blades is set to 95% when in automatic position; there is no limit when in manual position and it can be opened to 100%;

[0055] This application introduces a main induced draft fan quick adjustment system after judging the boiler coke-dropping conditions, so that the high negative pressure in the furnace disappears as soon as possible, preventing the fire from being extinguished due to the high II value of the furnace pressure when the boiler is coke-dropping, and improving the stability of the power generation boiler in the thermal power plant during operation;

[0056] In addition, once the inner wall of the boiler 1 is de-coked, the falling coal slag impacts the rubber pad 10 below, which then drives the corresponding slider 17 to slide on the corresponding sliding rheostat 9, that is, changes the operating power of the entire bypass induced draft fan 4, so that while the coke is falling, the suction strength of the bypass induced draft fan 4 is changed synchronously, and at the moment when the coal slag falls, the negative pressure strength in the boiler 1 is adjusted accordingly, thereby improving the air pressure regulation efficiency, further ensuring the stability of the air pressure in the boiler, and optimizing the stability of the boiler.

[0057] like Figure 1-2 , Figure 4-9As shown, the top of the boiler 1 is connected with a bypass interface 3, the bypass induced draft fan 4 is located at one side of the boiler 1, and one end of the bypass induced draft fan 4 is connected with a bypass negative pressure pipe 5, and the other end of the bypass negative pressure pipe 5 is connected with the bypass interface 3, the slag bucket 2 is coaxially arranged with the boiler 1, and one end of the slag bucket 2 is conically arranged, and a collecting trough 8 for collecting coal slag is also provided in the slag bucket 2, and a plurality of evenly distributed mounting seats are fixedly installed on the outer wall of the boiler 1, and a plurality of sliding rheostats 9 are respectively installed on the corresponding mounting seats, and the sliding vanes 17 are slidably clamped on the corresponding sliding rheostats 9, and are used to control the resistance value change of the sliding rheostats 9, and the plurality of sliding rheostats 9 are The bypass induced draft fan 4 is located in the same series circuit. A fixing ring 11 is fixedly sleeved on the inner wall of the boiler 1. A plurality of groups of vertical guide rods 12 are slidably sleeved on the fixing ring 11. The tops of the two vertical guide rods 12 at the same relative position are fixedly connected with the same rubber pad 10. The bottom ends of the vertical guide rods 12 are fixedly sleeved with a fixing plate 13. The vertical guide rods 12 are also sleeved with springs 14. The two ends of the spring 14 are respectively connected to the fixing ring 11 and the corresponding fixing plate 13. The same group of vertical guide rods 12 are also sleeved with arc-shaped connecting rods, and the arc-shaped connecting rods are connected to connecting blocks 15. A plurality of vertical slide grooves 16 are opened on the outer wall of the boiler 1. The connecting block 1 The slide block 17 is provided in the corresponding vertical slide groove 16, and insulating sheets 18 are installed on both sides of the connection block 15. A limit bar 19 matching the corresponding slide block 17 is installed on one side of the insulating sheet 18. The slide block 17 is connected between the insulating sheets 18 of the corresponding group through the limit bar 19. The same group of insulating sheets 18 is also threaded with bolts 20, which penetrate the corresponding slide block 17. When the inner wall of the boiler 1 is de-coked, the fallen coal slag first falls on the corresponding rubber pad 10 below. After the rubber pad 10 is subjected to the impact force, it slides downward under the guidance of the vertical guide rod 12. The spring 14 is deformed and compressed by the force, and the linkage effect with the insulating sheet 18 is achieved. The limiting effect of the limiting strip 19 drives the corresponding sliding piece 17 to slide on the sliding rheostat 9, thereby reducing the resistance and increasing the current in the series circuit of multiple sliding rheostats 9 and the bypass induced draft fan 4, thereby increasing the suction force of the bypass induced draft fan 4, stabilizing the pressure in the boiler 1. Compared with the prior art, the pressure value in the boiler 1 can be synchronously adjusted when coke drop occurs in the boiler 1, ensuring that the air pressure in the boiler 1 is relatively constant, and optimizing the stability of the boiler 1 during operation. Similarly, through the rebound effect of the spring 14, after the coke drop is completed, the rubber pad 10 can drive the sliding piece 17 to return to its original position, shut down the bypass induced draft fan 4, and save energy.

[0058] like Figure 4 As shown, the rubber pad 10 is arranged in an arc surface and is adapted to the position of the collecting trough 8. By arranging the rubber pad 10, it can not only have a buffering effect on the coked coal slag to avoid greater impact and wear on the slag bucket 2, but also can guide the fallen coal slag into the collecting trough 8 to achieve a guiding and collecting effect.

[0059] like Figure 3 , Figure 4 As shown, the boiler 1 is also provided with a central tube 7, which is located in a section inside the boiler 1 in the middle of the boiler 1, and both ends of the central tube 7 penetrate the boiler 1 and extend to the outside of the boiler 1. The boiler 1 is also provided with a spiral tube 6, which is close to the inner wall of the boiler 1, and both ends of the spiral tube 6 penetrate the boiler 1 and extend to the outside of the boiler 1. Both ends of the central tube 7 and the spiral tube 6 are connected with the external waterway. After the boiler 1 is operated, the central tube 7 and the spiral tube 6 are heated. In the present application, by arranging central tubes 7 and spiral tubes 6 with different layouts inside the boiler 1, more water sources can be fully heated by using coal flames when the boiler 1 is operating, thereby increasing the steam content and temperature per unit time, and improving the efficiency of thermal power generation.

[0060] The technical solution provided by the present invention introduces a main induced draft fan moving blade rapid adjustment system after judging the boiler coking conditions, so that the high negative pressure in the furnace disappears as soon as possible, thereby preventing fire extinguishing due to the high furnace pressure II value when the boiler cokes, and improving the stability of the power generation boiler in the thermal power plant during operation.

[0061] The falling coal slag impacts the rubber pad below, which in turn drives the corresponding slider to slide on the corresponding sliding rheostat, thereby changing the operating power of the entire bypass induced draft fan. As a result, the suction intensity of the bypass induced draft fan is changed synchronously while the coke is falling. At the moment when the coal slag falls, the negative pressure intensity in the boiler is adjusted accordingly, thereby further ensuring the stability of the air pressure in the boiler and optimizing the stability of the boiler.

[0062] By arranging central tubes and spiral tubes of different layouts inside the boiler, it is possible to utilize the coal flame to fully heat more water sources when the boiler is operating, thereby increasing the steam content and temperature per unit time and improving the efficiency of thermal power generation.

[0063] The present invention covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present invention. In order to make the public have a thorough understanding of the present invention, specific details are described in detail in the following preferred embodiments of the present invention, but those skilled in the art can fully understand the present invention without the description of these details. In addition, in order to avoid unnecessary confusion about the essence of the present invention, well-known methods, processes, procedures, components and circuits are not described in detail.

[0064] A person skilled in the art will appreciate that all or part of the steps in the above-mentioned embodiment method can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc.

[0065] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A furnace negative pressure control system for a boiler under coke-dropping conditions, comprising a boiler and a main induced draft fan connected to the boiler through a flue, characterized in that: A vibration measuring device, a furnace negative pressure measuring device and a negative pressure regulating device are connected to the water-cooled wall of the boiler; the vibration measuring device includes expansion recorders installed at the four corners of the boiler water-cooled wall, each of the expansion recorders is provided with a vibration measuring point, and the vibration measuring point is used to monitor the vibration value of the furnace bottom when the inner wall of the boiler is decoked; the furnace negative pressure measuring device includes a pressure transmitter and a pressure switch controller, and the pressure transmitter is used to sense the real-time pressure in the boiler through a sampling port, and when the real-time pressure reaches the negative pressure threshold, the negative pressure regulating device is shut down by the pressure switch controller; the negative pressure regulating device includes a main control unit, which is connected to the vibration signal acquisition circuit of the expansion recorder on the one hand, and is connected to the control circuit of the main induced draft fan on the other hand, so as to adaptively adjust the induced air volume of the main induced draft fan according to the vibration value obtained by the vibration measuring point.

2. The furnace negative pressure control system for boiler coking conditions according to claim 1 is characterized in that: The boiler is provided with a bypass interface, and the bypass interface is connected to a bypass induced draft fan through a bypass negative pressure pipe. A slag hopper for collecting coal slag is provided at the bottom of the boiler. The bottom end of the boiler is also provided with a trigger component for correspondingly controlling the operating power of the bypass induced draft fan when coke is dropped from the inner wall of the boiler. The trigger component includes a plurality of groups of sliding rheostats and rubber pads with corresponding positions. The sliding rheostats and the bypass induced draft fan are located in the same series circuit. When the rubber pad is hit by coke drop on the inner wall of the boiler, it can synchronously drive the sliding vane on the corresponding sliding rheostat to move, so as to increase the induced air volume of the bypass induced draft fan, thereby cooperating with the main induced draft fan to adjust the boiler pressure.

3. The furnace negative pressure control system for boiler coking conditions according to claim 2 is characterized in that: The slag hopper is coaxially arranged with the boiler, and one end of the slag hopper is arranged in a cone shape. A collecting trough for collecting coal slag is also arranged in the slag hopper.

4. The furnace negative pressure control system for boiler coking condition according to claim 3 is characterized in that: The boiler is also provided with a central tube, wherein a section of the central tube is located in the middle of the boiler, and both ends of the central tube penetrate the boiler and extend to the outside of the boiler.

5. The furnace negative pressure control system for boiler coking condition according to claim 4 is characterized in that: A spiral tube is also provided in the boiler. The spiral tube is close to the inner wall of the boiler, and both ends of the spiral tube pass through the boiler and extend to the outside of the boiler. Both ends of the central tube and the spiral tube are connected to the external water channel. After the boiler is operated, the central tube and the spiral tube are both heated.

6. The furnace negative pressure control system for boiler coking conditions according to any one of claims 3 to 5, characterized in that: A plurality of evenly distributed mounting seats are fixedly mounted on the outer wall of the boiler, and a plurality of sliding rheostats are respectively mounted on the corresponding mounting seats, and the slide plate is slidingly clamped on the corresponding sliding rheostat and is used to control the change of the resistance value of the sliding rheostat, and the plurality of sliding rheostats are all located in the same series circuit with the bypass induced draft fan.

7. The furnace negative pressure control system for boiler coking conditions according to claim 6 is characterized in that: A fixing ring is fixedly sleeved on the inner wall of the boiler, and a plurality of groups of vertical guide rods are slidably sleeved on the fixing ring. The top ends of two vertical guide rods at the same relative position are fixedly connected with the same rubber pad.

8. The furnace negative pressure control system for boiler coking conditions according to claim 7 is characterized in that: The rubber pad is arranged in an arc surface and is adapted to the position of the collecting tank.

9. The furnace negative pressure control system for boiler coking condition according to claim 7 or 8, characterized in that: A fixing plate is fixedly sleeved on the bottom end of the vertical guide rod, and a spring is sleeved on the vertical guide rod. Two ends of the spring are respectively connected to the fixing ring and the corresponding fixing plate.

10. The furnace negative pressure control system for boiler coking condition according to claim 9, characterized in that: An arc-shaped connecting rod is also sleeved on the same group of vertical guide rods, and a connecting block is connected to the arc-shaped connecting rod. A plurality of vertical slide grooves are opened on the outer wall of the boiler, and the connecting block is slidably clamped in the corresponding vertical slide grooves, and insulating sheets are installed on both sides of the connecting block, and a limiting strip adapted to the corresponding slide is installed on one side of the insulating sheet, and the slide is clamped between the insulating sheets of the corresponding group through the limiting strip, and bolts are also threadedly sleeved on the insulating sheets of the same group, and the bolts pass through the corresponding slide.

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