Dust removal system and dust removal method

Abstract

To provide a dust removal system and a dust removal method, which can more reliably remove dust from within a combustor.SOLUTION: A dust removal system comprises two shock wave generation devices each configured so as to generate a shock wave for removing dust in a combustor. The two shock wave generation devices each include: a chamber configured so as to be filled with a mixture containing a fuel and an oxidizing agent; an ignition device for igniting the mixture in the chamber; and a launch unit for using a detonation wave produced by the ignition by the ignition device to launch a shock wave into the combustor. The two shock wave generation devices are arranged so that two shock waves respectively launched from the two launch units reinforce one another due to interference. The dust removal system further comprises an ignition control unit configured so as to send, to each of the two ignition devices, an ignition command for starting ignition.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a dust removal system and a dust removal method that removes dust in a combustor using shock waves. [Background technology]

[0002] Conventionally, dust removal systems have been known that use shock waves to remove dust from combustors. Dust is composed of fine particles containing at least one of carbon, chlorine, sulfur, and precious metals, which are generated during fuel combustion. Examples of fine particles containing carbon include soot.

[0003] The dust removal system disclosed in Patent Document 1 is applied to a boiler, which is an example of a combustor. The dust removal system includes two shock wave generators, and the two shock waves emitted from the two shock wave generators interfere and constructively interfere with each other inside the boiler. Dust accumulated inside the boiler is removed at the location where the two shock waves constructively interfere with each other. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-320331 Summary of the Invention [Problem to be solved by the invention]

[0005] Each of the two shock wave generators in the above-mentioned Patent Document 1 is equipped with a Schelkin spiral for transitioning a flame to a detonation. Adjusting the position of the Schelkin spiral changes the timing at which the flame transitions to a detonation. Therefore, the timing at which each of the two shock wave generators generates a detonation wave is adjusted, and as a result, the interference position of the two shock waves in the boiler is adjusted.

[0006] However, adjusting the position of the Schelkin spiral is not easy as it involves adjusting a mechanical structure, and if this position adjustment is not made accurately, the interference position of the shock wave cannot be adjusted with precision, which may result in the target dust in the combustor not being removed.

[0007] An object of the present disclosure is to provide a dust removal system and a dust removal method that can more reliably remove dust from within a combustor. [Means for solving the problem]

[0008] A dust removal system according to at least one embodiment of the present disclosure comprises: A dust removal system comprising two shock wave generating devices each configured to generate a shock wave for removing dust in a combustor, Each of the two shock wave generating devices is a chamber configured to be filled with a mixture comprising a fuel and an oxidizer; an ignition device for igniting the mixture within the chamber; a launching unit for launching the shock wave into the combustor by utilizing a detonation wave generated by ignition by the ignition device; Including, The two shock wave generators are arranged so that the two shock waves emitted from the two emission units can be reinforced by interference, The dust removal system further includes an ignition control unit configured to send an ignition command to each of the two ignition devices to start ignition.

[0009] A dust removal method according to an embodiment of the present disclosure includes: A dust removal method for removing dust in a combustor by using two shock waves emitted from two shock wave generators, an estimation step of estimating a position of the dust in the combustor based on a detection result of a temperature detection unit for detecting a temperature distribution in the combustor; A determination step for determining a first time lag, which is a time lag for the two shock waves emitted using detonation waves generated inside the two shock wave generators at the estimated position of the estimated dust to reinforce each other by interference; a first command sending step of sending an ignition command to start ignition to each of two ignition devices of the two shock wave generating devices so that the first time lag is generated; Equipped with. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to provide a dust removal system and a dust removal method that can more reliably remove dust from inside a combustor. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram of a dust removal system according to one embodiment. [Figure 2] FIG. 2 is a schematic diagram of a controller according to one embodiment. [Figure 3] FIG. 2 is a schematic diagram of a temperature detection unit according to an embodiment. [Figure 4] FIG. 10 is a schematic diagram illustrating a change in the interference position of a shock wave according to an embodiment. [Figure 5] 10 is a flowchart illustrating a dust removal control process according to an embodiment. [Figure 6] FIG. 10 is a schematic diagram of a temperature detection unit according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, several embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present disclosure. For example, expressions expressing relative or absolute arrangement such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" not only express such an arrangement exactly, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions such as "identical," "equal," and "homogeneous" that indicate that something is in an equal state not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained. For example, expressions representing shapes such as a square shape or a cylindrical shape not only represent shapes such as a square shape or a cylindrical shape in the strict geometric sense, but also represent shapes including uneven portions, chamfered portions, etc., to the extent that the same effect can be obtained. On the other hand, the expressions "comprise," "include," or "have" one element are not exclusive expressions that exclude the presence of other elements. Note that the same components will be denoted by the same reference numerals and the description thereof will be omitted.

[0013] <Dust Removal System 1> 1 is a schematic diagram of a dust removal system 1 according to one embodiment of the present disclosure. The dust removal system 1 is configured to remove dust 2 in a combustor using shock waves. The following describes an embodiment in which the dust removal system 1 is applied to a boiler 3 as an example of a combustor.

[0014] The boiler 3 includes a furnace wall 18. Combustion of boiler fuel generates combustion gas in the space inside the furnace wall 18. If dust 2 in the combustion gas adheres to the furnace wall 18, heat exchange in the boiler heat transfer tubes 17 (see FIG. 6 ) that form the furnace wall 18 is hindered. Therefore, the adhered dust 2 needs to be removed. Therefore, the dust removal system 1 illustrated in FIG. 1 includes two shock wave generators 5A and 5B, each configured to generate shock waves. Hereinafter, the shock wave generators 5A and 5B may be collectively referred to as the "shock wave generator 5." Furthermore, although the following describes an embodiment in which dust 2 on the furnace wall 18 is the target of removal, the present disclosure is not limited thereto. Dust 2 on the heat transfer tubes of a superheater or reheater that constitutes the boiler 3 may also be the target of removal.

[0015] Each shock wave generator 5 is configured to generate a shock wave W. The shock wave generator 5 includes a chamber 7, an ignition device 9, and a launch unit 8. Fuel and oxidizer are supplied to the chamber 7, and the chamber 7 is filled with a mixture containing the fuel and the oxidizer. The mixing of the fuel and the oxidizer may occur in the chamber 7 or may occur upstream of the chamber 7. The ignition device 9 is configured to ignite the mixture in the chamber 7. A flame generated in the chamber 7 by ignition of the ignition device 9 transitions to a detonation, generating a detonation wave in the chamber 7. The launch unit 8 launches a shock wave W into the boiler 3 by utilizing the detonation wave.

[0016] The two shock wave generators 5A, 5B are arranged so that the two shock waves W emitted from the two emission units 8 can interfere with each other and reinforce each other. The pressure of the shock wave W is highest when the shock wave W is emitted from the emission unit 8. In this embodiment, because the effect of strengthening the shock wave W is obtained by interference, it is not necessary to increase the strength (pressure) of the shock wave W when it is emitted from the emission unit 8. This makes it possible to reduce stress generated in the furnace wall 18 and extend the life of the boiler 3.

[0017] As described above, each of the shock wave generators 5A and 5B is equipped with an ignition device 9. For ease of explanation, the ignition device 9 of the shock wave generator 5A may be referred to as the "ignition device 9A," and the ignition device 9 of the shock wave generator 5B may be referred to as the "ignition device 9B." The ignition devices 9A and 9B are controlled by a controller 30, which is a component of the dust removal system 1. The controller 30 is configured by a computer and includes a processor, a memory (storage medium), and an external communication interface.

[0018] The controller 30 includes an ignition control unit 33 for controlling the ignition operation of the shock wave generators 5A and 5B. The ignition control unit 33 is configured to send an ignition command C to each of the ignition devices 9A and 9B to start ignition. The ignition command C may be sent to the ignition devices 9A and 9B simultaneously. In this case, two shock waves W interfere with each other and reinforce each other at an intermediate position M between the shock wave generators 5A and 5B. Therefore, the composite wave of the two shock waves W generated by the interference can remove the dust 2 at the intermediate position M.

[0019] However, because the dust 2 adheres to the furnace wall 18 at various locations during operation of the boiler 3, the dust 2 is not necessarily located at the intermediate position M (see FIG. 3). Therefore, the ignition control unit 33 may shift the timing of issuing the ignition command C between the ignition devices 9A and 9B. This causes the two shock waves W to interfere and reinforce each other at a position shifted from the intermediate position M toward the ignition device 9A or toward the ignition device 9B. Therefore, the composite wave of the two shock waves W can remove the dust 2 located at a position shifted from the intermediate position M.

[0020] According to the above configuration, the shock waves W emitted from the shock wave generator 5 are generated using detonation waves, and the ignition control unit 33 issues the ignition command C as an electrical signal to the ignition device 9. Therefore, the time required from when the ignition control unit 33 issues the ignition command C to when the shock waves W are emitted into the boiler 3 can be set to approximately 10 ms or less, preferably 5 ms or less. Therefore, the time difference between when the shock waves W are emitted into the boiler 3 between the two shock wave generators 5A and 5B can be set to approximately 10 ms or less, preferably 5 ms or less. This allows the position where the shock waves W are combined to match the desired position with high accuracy, thereby realizing a dust removal system 1 that can more reliably remove dust 2 from the boiler 3.

[0021] In some embodiments, the ignition control unit 33 can adjust the time lag between issuing an ignition command C to the ignition device 9A and issuing an ignition command C to the ignition device 9B. By way of example only, the range of the time lag is 5 ms or more and 20 ms or less, more specifically, 5 ms or more and 10 ms or less. The specific value of the time lag varies depending on how far the dust 2 is from the intermediate position M.

[0022] According to the above configuration, the ignition control unit 33 adjusts the time lag, allowing the dust removal system 1 to adjust with high precision the position where the shock waves W interfere. As a result, even if the dust 2 in the boiler 3 is located at a position shifted from the midpoint M between the two shock wave generators 5A and 5B, the dust removal system 1 can remove the dust 2.

[0023] In some embodiments, the ignition devices 9A, 9B illustrated in FIG. 1 are spark plugs configured to generate sparks by discharging in the respective chambers 7. The spark plugs execute discharge upon receiving an ignition command C. The sparks generated by the discharge ignite the mixture, generating a flame in each chamber 7.

[0024] According to the above configuration, the spark plug that receives the ignition command C generates a spark by discharging, thereby shortening the time required for ignition to occur after the ignition control unit 33 issues the ignition command C. This further shortens the time required for the shock wave W to be emitted into the boiler 3 after the ignition control unit 33 issues the ignition command C.

[0025] <Details of the ignition control unit 33> 2 is a schematic diagram showing an ignition control unit 33 of a controller 30 according to an embodiment of the present disclosure. The ignition control unit 33 shown in the figure estimates the position of dust 2 adhering to the furnace wall 18 in the boiler 3 and controls the ignition devices 9A and 9B so that interference between two shock waves W occurs at the estimated position of the dust 2. To estimate the position of the dust 2, a temperature detection unit 11 for detecting the temperature distribution on the furnace wall 18 is used.

[0026] The estimation of the position of the dust 2 is carried out by an estimation unit 34, which is a component of the ignition control unit 33. The estimation unit 34 estimates the position of the dust 2 based on the detection results of the temperature detection unit 11. Because the temperature differs between the location on the furnace wall 18 where the dust 2 is present and the location where it is not, the position of the dust 2 can be estimated from the detection results of the temperature detection unit 11. If the estimated position of the dust 2 is known, it is also possible to determine the distance between the dust 2 and the intermediate position M. Note that if the dust 2 is present at the intermediate position M, the above distance is zero.

[0027] 3 illustrates an embodiment in which a thermographic camera 15 is used as the temperature detection unit 11. The thermographic camera 15 is configured to send a captured image Im showing the temperature distribution on the furnace wall 18 of the boiler 3 to the estimation unit 34. The captured image Im includes a plurality of evenly divided image regions R, and the temperature of the furnace wall 18 determined by measurement by the thermographic camera 15 is embedded as data in each image region R.

[0028] When dust 2 adheres (accumulates), heat exchange between the water or steam flowing inside the boiler heat transfer tubes 17 (see FIG. 6) that make up the furnace wall 18 and the combustion gas inside the furnace wall 18 is hindered. In other words, the dust 2 on the furnace wall 18 functions similarly to heat insulation. The thermographic camera 15 detects the surface temperature of the dust 2 on the furnace wall 18, and as a result, the temperature of the furnace wall 18 detected by the thermographic camera 15 rises. Therefore, if there is an image region R among the multiple image regions R whose temperature exceeds a first specified temperature, the estimation unit 34 estimates that dust 2 is present at the position on the furnace wall 18 that corresponds to that image region R. In FIG. 3, the temperature corresponding to the hatched image region R exceeds the first specified temperature.

[0029] Returning to FIG. 2, the ignition control unit 33 further includes a determination unit 35 and a first command transmission unit 31. The determination unit 35 determines the above-mentioned time lag required for the two shock waves W to interfere and reinforce each other at the estimated position of the dust 2 as the first time lag. As just one example, the first time lag is calculated based on the distance between the estimated position of the dust 2 and the intermediate position M, and the speed of the shock wave W. Note that the position of the intermediate position M and the speed of the shock wave W are specified in advance.

[0030] The first command transmitting unit 31 executes a first ignition control that sends an ignition command C to each of the ignition devices 9A and 9B so as to generate a first time lag. If the shock waves W ideally travel through the boiler 3 as a result of the first ignition control, the two shock waves W will interfere with each other and reinforce each other at the estimated position estimated by the estimating unit 34. As a result, the dust 2 at the estimated position is removed.

[0031] The temperature differs between the location on the furnace wall 18 where dust 2 is present and the location where it is not. More specifically, the temperature inside the boiler 3 is relatively high near the dust 2 adhering to the inner wall surface of the furnace wall 18. Therefore, with the above configuration, the estimation unit 34 can accurately estimate the position of the target dust 2 based on the detection results of the thermographic camera 15, and the interference of the shock wave W can be caused at the estimated position of the dust 2. This allows the target dust 2 to be reliably removed.

[0032] The description of the ignition control unit 33 continues with reference to Fig. 2. In some embodiments, the ignition control unit 33 further includes a determination unit 36 ​​and a second command transmission unit 32.

[0033] After the first ignition control is executed, the determination unit 36 ​​determines whether the dust 2 has been removed from the estimated position based on the detection result of the temperature detection unit 11. More specifically, after the first ignition control, the temperature detection unit 11 again detects the temperature distribution in the boiler 3 and sends the detection result to the determination unit 36. More specifically, a new captured image Im captured by the thermographic camera 15 is sent to the determination unit 36. If the temperature of the image region R in the captured image Im that corresponds to the estimated position is equal to or lower than the first specified temperature, the determination unit 36 ​​determines that the dust 2 has been removed; otherwise, the determination unit 36 ​​determines that the dust 2 has not been removed.

[0034] If it is determined that the dust 2 has not been removed, the second command transmitter 32 executes a second ignition control to send an ignition command C to each of the ignition devices 9A, 9B so as to generate a second time lag that is different from the first time lag. This allows the shock waves W to interfere at a position different from that when the first ignition control is executed.

[0035] FIG. 4 is a schematic diagram showing changes in the interference position of shock waves W. Point E indicates the estimated position of dust 2 estimated by the estimation unit 34. Point P1 indicates the position where the shock waves W constructively interfere with each other due to the first ignition control. The first time lag determined by the determination unit 35 is intended to cause the shock waves W to interfere at point E. If the shock waves W ideally progress through the boiler 3, point P1 where the interference occurs will coincide with point E. However, in reality, due to various factors, the shock waves W may interfere at a position displaced from point E, and the target dust 2 may not be removed. In this case, in this embodiment, the second ignition control is further executed, and the next two shock waves W constructively interfere with each other at point P2, which is different from point P1. If point P2 is near point E, the dust 2 is removed.

[0036] According to the above configuration, if the dust 2 is not removed even after the first ignition control is executed, the second command transmitter 32 executes the second ignition control. This makes it possible to cause the shock wave W to interfere at a position (point P2) different from the position (point P1) of interference caused by the first ignition control. Since the position of interference caused by the second ignition control is likely to be close to the estimated position (point E) of the dust 2, the targeted dust 2 can be removed more reliably.

[0037] In some embodiments, the first ignition control is configured to be executed periodically, for example, every hour. That is, every hour, temperature detection by temperature detection unit 11, estimation processing by estimation unit 34, determination processing by determination unit 35, and determination processing by determination unit 36 ​​are executed. The first period may be two hours, three hours, or four hours or more.

[0038] In contrast, the time required for the second command transmitting unit 32 to complete the second ignition control after it is determined that the dust 2 has not been removed is within 10 minutes, more specifically within 5 minutes. In other words, when the determining unit 36 ​​determines that the dust 2 has not been removed, the second command transmitting unit 32 executes the second ignition control before the next execution of the first ignition control. This allows the dust 2 that could not be removed by the first ignition control to be removed early.

[0039] The dust removal control process (dust removal method) will be described with reference to Figure 5. This control process is a process that is continuously executed by a processor constituting the controller 30 of the dust removal system 1 while the boiler 3 is in operation. In the following description, steps may be abbreviated as "S".

[0040] First, the processor estimates the position of the dust 2 based on the detection result of the temperature detection unit 11 (S1). The processor that executes S1 is an example of the estimation unit 34. Next, the processor determines the first time lag described above (S3). The processor that executes S3 is an example of the determination unit 35. Next, the processor executes the first ignition control to send an ignition command C to the ignition devices 9A, 9B so that the first time lag occurs (S5). The processor that executes S5 is an example of the first command transmission unit 31.

[0041] Next, the processor determines whether dust 2 has been removed from the estimated position estimated in S1 based on the detection result of the temperature detection unit 11 (S7). The processor that executes S7 is an example of the determination unit 36. If it is determined that dust 2 has been removed (S7: YES), the processor proceeds to S11, which will be described later. If it is determined that dust 2 has not been removed (S7: NO), the processor executes second ignition control (S9). The second ignition control is control that sends an ignition command C to each of the ignition devices 9A, 9B so that a second time lag different from the first time lag occurs. The processor that executes S9 is an example of the second command transmission unit 32.

[0042] Next, the processor determines whether the first period has elapsed since S1 was started (S11). If the first period has elapsed (S11: NO), the processor waits. If it is determined that the first period has elapsed (S11: YES), the processor returns the process to S1. After that, the following steps S1 to S7 are executed in order, and if dust 2 has not been removed (S7: NO), S9 is executed.

[0043] <Modification> 6 is a schematic diagram showing a temperature detection unit 11 according to a modified example. The temperature detection unit 11 shown in the figure is a temperature sensor 16 configured to detect the metal temperature of a plurality of boiler heat transfer tubes 17 that constitute a furnace wall 18. As a more specific example, the temperature sensor 16 is a plurality of thermocouples attached to the plurality of boiler heat transfer tubes 17, respectively. If there is a boiler heat transfer tube 17 among the plurality of boiler heat transfer tubes 17 whose metal temperature detected by the temperature sensor 16 is lower than a second specified temperature, the estimation unit 34 estimates that dust 2 is present on that boiler heat transfer tube 17.

[0044] When dust 2 accumulates on the boiler heat transfer tubes 17, the dust 2 inhibits heat exchange in the boiler heat transfer tubes 17. This causes a drop in the metal temperature near the location where the dust 2 has accumulated. Therefore, with the above configuration, the estimation unit 34 can accurately estimate the location of the dust 2 based on whether the metal temperature is below the second specified temperature, thereby ensuring reliable removal of the targeted dust 2.

[0045] The temperature sensor 16 shown in FIG. 6 may be an optical fiber instead of a thermocouple, and more specifically, may be a single optical fiber of a multi-point measurement type that can detect the metal temperature of each boiler heat transfer tube 17.

[0046] <Other> As described above, the controller 30 includes a processor, a memory (storage medium), and an external communication interface. The processor may be a CPU, a GPU, an MPU, a DSP, or a combination thereof. In other embodiments, the processor may be implemented by an integrated circuit such as a PLD, an ASIC, an FPGA, or an MCU. The memory is configured to temporarily or non-temporarily store various data and may be implemented by at least one of a RAM, a ROM, or a flash memory. The processor executes various control processes according to instructions from a program loaded into the memory. The controller 30 may also be a DCS panel that constitutes one of multiple control panels for a boiler plant.

[0047] In the present disclosure, the multiple installed shock wave generators 5 may include at least one set of two shock wave generators 5 positioned such that their shock waves interfere with each other. There is no problem if multiple sets of shock wave generators 5 with the above-described positional relationship are provided. There is also no problem if one shock wave generator 5 is shared between one set of shock wave generators 5 and another set of shock wave generators 5. In this case, three shock wave generators 5 may be positioned such that their shock waves interfere with each other.

[0048] The combustor to which the dust removal system 1 is applied is not limited to the boiler 3. The combustor may be, for example, a gas turbine combustor. In this case, two shock wave generating devices 5 may be attached to the combustion liner of the gas turbine combustor.

[0049] <Summary> The contents of the above-described embodiments can be understood, for example, as follows.

[0050] 1) A dust removal system (1) according to at least one embodiment of the present disclosure includes: A dust removal system comprising two shock wave generators (5) each configured to generate shock waves (W) for removing dust in a combustor (boiler 3), Each of the two shock wave generating devices is a chamber (7) configured to be filled with a mixture containing a fuel and an oxidizer; an ignition device (9) for igniting the mixture in the chamber; a launching unit (8) for launching the shock wave into the combustor by utilizing a detonation wave generated by ignition by the ignition device; Including, The two shock wave generators are arranged so that the two shock waves emitted from the two emission units can be reinforced by interference, The dust removal system further includes an ignition control unit (33) configured to send an ignition command to each of the two ignition devices to start ignition.

[0051] According to the configuration of 1) above, the composite wave generated by the two shock waves constructively interfering with each other can remove dust from the combustor. Because the shock wave is generated by utilizing a detonation wave and the ignition control unit issues an ignition command as an electrical signal to the ignition device, the time required from the issuance of the ignition command by the ignition control unit to the emission of the shock wave into the combustor can be set to approximately 10 ms or less, preferably 5 ms or less. Therefore, the time difference between the emission of the shock waves into the combustor between the two shock wave generators can be set to approximately 10 ms or less, preferably 5 ms or less. This allows the position where the combined shock waves occur to be aligned with the desired position with high accuracy, thereby realizing a dust removal system that can more reliably remove dust from the combustor.

[0052] 2) In some embodiments, the dust removal system according to 1) above, The ignition control unit is configured to be able to adjust the time lag between issuing the ignition command to one of the two ignition devices and issuing the ignition command to the other.

[0053] According to the configuration of 2) above, the ignition control unit adjusts the time lag, which allows the dust removal system to adjust the position where the shock waves are combined with high precision. As a result, even if dust in the combustor is located at a position that is shifted from the midpoint (M) between the two shock wave generators, the dust removal system can remove the dust.

[0054] 3) In some embodiments, the dust removal system described in 2) above comprises: a temperature detection unit (11) for detecting a temperature distribution in the combustor; The ignition control unit an estimation unit (34) for estimating a position of the dust in the combustor based on a detection result of the temperature detection unit; a determination unit (35) for determining a first time lag, which is the time lag required for the two shock waves to constructively interfere with each other at the estimated position (point E) of the dust estimated by the estimation unit; a first command transmission unit (31) for executing a first ignition control that sends the ignition command to each of the two ignition devices so that the first time lag is generated; Includes:

[0055] The temperature differs between areas in the combustor where dust is present and areas where it is not. Therefore, with the configuration of 3) above, the estimation unit can accurately estimate the position of the target dust, and shock wave interference can be caused within the combustor based on the estimation result. This allows the target dust to be reliably removed.

[0056] 4) In some embodiments, the dust removal system according to 3) above, The ignition control unit a determination unit (36) for determining whether the dust has been removed at the estimated position based on a detection result of the temperature detection unit after the first ignition control is executed; a second command transmitting unit (32) for executing a second ignition control to transmit the ignition command to each of the two ignition devices so that a second time lag, which is different from the first time lag, occurs when it is determined that the dust has not been removed; Further includes:

[0057] According to the configuration of 4) above, if the dust is not removed even after the first ignition control is executed, the second command transmitter executes the second ignition control. This makes it possible to cause shock wave interference at a position (point P2) different from the position of interference caused by the first ignition control (point P1). Since the position of interference caused by the second ignition control is likely to be close to the estimated position of the dust, the targeted dust can be removed more reliably.

[0058] 5) In some embodiments, the dust removal system according to 4) above, the first command transmitter is configured to periodically execute the first ignition control; The determination unit is configured to determine whether the dust has been removed every time the first ignition control is executed, The second command transmitter is configured to execute the second ignition control before the next execution of the first ignition control when it is determined that the dust has not been removed.

[0059] According to the configuration of 5) above, if the targeted dust is not removed through the first ignition control, the second ignition control is executed before the next execution of the first ignition control, thereby enabling the dust that could not be removed by the first ignition control to be removed early.

[0060] 6) In some embodiments, the dust removal system according to any one of 3) to 5) above, the temperature detection unit is a thermography camera configured to detect a temperature distribution in the combustor, The estimation unit is configured to estimate that, when there is an image area (R) in the image (Im) captured by the thermographic camera where the temperature exceeds a first specified temperature, the dust is present at a position in the combustor corresponding to the image area.

[0061] The temperature inside the combustor near the dust accumulated on the inner wall surface of the combustor is relatively high. Therefore, with the configuration of 6) above, the estimation unit can accurately estimate the position of the dust based on the detection results of the thermographic camera, so the targeted dust can be reliably removed.

[0062] 7) In some embodiments, the dust removal system according to any one of 3) to 6) above, the temperature detection unit is a temperature sensor (16) configured to detect a metal temperature of each of a plurality of heat transfer tubes (a plurality of boiler heat transfer tubes 17) of the combustor, The estimation unit is configured to estimate that the dust is present on a heat transfer tube when the metal temperature detected by the temperature sensor of any of the plurality of heat transfer tubes is lower than a second specified temperature.

[0063] When dust accumulates on the heat transfer tubes of a combustor, the dust impedes heat exchange in the tubes. This causes the metal temperature near the dust accumulation location to drop. Therefore, with the configuration of 7) above, the estimation unit can accurately estimate the dust location based on the detection results of the temperature sensor, allowing the targeted dust to be reliably removed.

[0064] 8) In some embodiments, the dust removal system according to any one of 1) to 7) above, The ignition device is a spark plug configured to generate a spark by discharging electricity in the chamber.

[0065] According to the configuration of 8) above, the spark plug generates a spark by discharging when it receives an ignition command, which shortens the time required for ignition to occur after the ignition control unit issues the ignition command, thereby further shortening the time required for a shock wave to be emitted into the combustor after the ignition control unit issues the ignition command.

[0066] 9) A dust removal method according to at least one embodiment of the present disclosure, comprising: A dust removal method for removing dust in a combustor (boiler 3) by using two shock waves emitted from two shock wave generators (5), an estimation step (S1) of estimating the position of the dust in the combustor based on a detection result of a temperature detection unit (11) for detecting a temperature distribution in the combustor; A determination step (S3) for determining a first time lag, which is a time lag for the two shock waves emitted using detonation waves generated inside the two shock wave generators at the estimated position of the estimated dust to reinforce each other by interference; a first command transmission step (S5) of sending an ignition command to start ignition to each of the two ignition devices (9) of the two shock wave generators so that the first time lag is generated; Equipped with.

[0067] According to the configuration 9) above, the same technical advantages as those in 3) above can be obtained. [Explanation of symbols]

[0068] 1: Dust removal system 2: Dust 3: Boiler 5: Shock wave generator 5A: Shock wave generator 5B: Shock wave generator 7: Chamber 8: Launch unit 9:Ignition device 9A:Ignition device 9B:Ignition device 11: Temperature detection unit 12: Exhaust Room 13: Taxiway 14: Convergence Room 15: Thermography camera 16: Thermocouple sensor 17: Boiler heat transfer tube 18: Furnace wall 30: Controller 31: First command transmitter 32: Second command transmitter 33: Ignition control unit 34:Estimation part 35: Decision section 36: Judgment section C: Ignition command Im: Captured image M: Middle position R: Image region W: Shock wave

Claims

1. A dust removal system comprising two shock wave generating devices each configured to generate a shock wave for removing dust in a combustor, Each of the two shock wave generating devices is a chamber configured to be filled with a mixture comprising a fuel and an oxidizer; an ignition device for igniting the mixture within the chamber; a launching unit for launching the shock wave into the combustor by utilizing a detonation wave generated by ignition by the ignition device; Including, The two shock wave generators are arranged so that the two shock waves emitted from the two emission units can be reinforced by interference, The dust removal system further includes an ignition control unit configured to send an ignition command to each of the two ignition devices to start ignition. Dust removal system.

2. The ignition control unit is configured to be able to adjust the time lag between issuing the ignition command to one of the two ignition devices and issuing the ignition command to the other. The dust removal system of claim 1 .

3. a temperature detection unit for detecting a temperature distribution in the combustor, The ignition control unit an estimation unit for estimating a position of the dust in the combustor based on a detection result of the temperature detection unit; a determination unit for determining a first time lag, which is the time lag required for the two shock waves to constructively interfere with each other at the estimated position of the dust estimated by the estimation unit; and a first command transmission unit for executing a first ignition control that transmits the ignition command to each of the two ignition devices so that the first time lag is generated; Contains The dust removal system of claim 2 .

4. The ignition control unit a determination unit for determining whether the dust has been removed at the estimated position based on a detection result of the temperature detection unit after the first ignition control is executed; a second command sending unit for executing a second ignition control that sends an ignition command to each of the two ignition devices so that a second time lag, which is different from the first time lag, occurs when it is determined that the dust has not been removed; and Also includes The dust removal system of claim 3 .

5. the first command transmitter is configured to periodically execute the first ignition control; the determination unit is configured to determine whether the dust has been removed every time the first ignition control is executed, The second command transmitting unit is configured to execute the second ignition control before the next execution of the first ignition control when it is determined that the dust has not been removed. The dust removal system of claim 4 .

6. the temperature detection unit is a thermography camera configured to detect a temperature distribution in the combustor, The estimation unit is configured to estimate that the dust is present at a position in the combustor corresponding to an image area in which the temperature exceeds a first specified temperature when the image captured by the thermographic camera includes the image area. A dust removal system according to any one of claims 3 to 5.

7. the temperature detection unit is a temperature sensor configured to detect a metal temperature of each of a plurality of heat transfer tubes of the combustor, The estimation unit is configured to estimate that the dust is present on a heat transfer tube when the metal temperature detected by the temperature sensor is lower than a second specified temperature among the plurality of heat transfer tubes. A dust removal system according to any one of claims 3 to 5.

8. The ignition device is a spark plug configured to generate a spark by discharging electricity in the chamber. A dust removal system according to any one of claims 1 to 3.

9. A dust removal method for removing dust in a combustor by using two shock waves emitted from two shock wave generators, comprising: an estimation step of estimating a position of the dust in the combustor based on a detection result of a temperature detection unit for detecting a temperature distribution in the combustor; A determination step for determining a first time lag, which is a time lag for the two shock waves emitted using detonation waves generated inside the two shock wave generators at the estimated position of the estimated dust to reinforce each other by interference; a first command transmission step of transmitting an ignition command to start ignition to each of two ignition devices of the two shock wave generators so that the first time lag is generated; A dust removal method comprising:

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