Shock wave generating device

Abstract

A shock wave generating device is provided with: a combustion device provided with a gas passage through which a combustion gas flows from a base end to a tip end, the combustion device being provided with an opening at the tip end; a combustible gas supply device for supplying a combustible gas from the base end of the combustion device to the inside; an ignition device that ignites the combustible gas supplied to the combustion device; a flame generation period detection sensor that detects the generation period of flame caused by combustion of the combustible gas; and a determination device that determines the spontaneous combustion of the combustible gas before ignition by the ignition device on the basis of the detection result of the flame generation period detection sensor.

Description

Technical Field

[0001] The present disclosure relates to a shock wave generating device for generating shock waves produced by a detonation. Background Art

[0002] For example, dust contained in the exhaust gas of waste incinerators, coal gasification combined power plants (IGCC), power generation boilers, etc. will adhere to the inner wall surface of the furnace and the outer surface of the heat transfer tube. The dust attached to the inner wall surface of the furnace and the outer surface of the heat transfer tube reduces the heat transfer rate and deteriorates the heat recovery efficiency, or becomes a resistance to the flow of exhaust gas and reduces the performance of the furnace. Therefore, it is necessary to regularly remove the dust attached to the inner wall of the furnace and the outer surface of the heat transfer tube by a dust removal device.

[0003] The dust removal device has a shock wave generating device. The shock wave generating device generates a shock wave generated by a detonation in which the propagation speed of the flame exceeds the speed of sound by burning fuel. The dust removal device removes dust by the shock wave generated by the shock wave generating device. As such a conventional shock wave generating device, there is a device described in the following patent document.

[0004] Prior art literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 60-205120

[0006] Patent Document 1: Japanese Patent Application Publication No. 2002-106826 Summary of the invention

[0007] Problems to be solved by the invention

[0008] Conventional shock wave generating devices ignite a mixture of fuel and oxidant, and generate shock waves caused by detonation through combustion of the mixture. At this time, sometimes a detonation wave is not generated due to the form of combustion, but a deflagration wave is generated, for example, dust may not be properly removed. In addition, before the mixture is ignited, the mixture sometimes self-ignites and flashes. Therefore, the shock wave generating device needs to determine whether detonation has occurred properly.

[0009] The present disclosure is to solve the above-mentioned problems, and an object of the present disclosure is to provide a shock wave generating device capable of determining the combustion state of fuel.

[0010] Means for solving problems

[0011] The shock wave generating device disclosed in the present invention for achieving the above-mentioned purpose comprises: a combustion device, which is provided with a gas passage for combustion gas to flow from the base end to the front end and is provided with an opening at the above-mentioned front end; a combustible gas supply device, which supplies combustible gas from the above-mentioned base end to the inside of the above-mentioned combustion device; an ignition device, which ignites the above-mentioned combustible gas supplied to the above-mentioned combustion device; a flame generation period detection sensor, which detects the generation period of flame caused by the combustion of the above-mentioned combustible gas; and a judgment device, which judges the self-ignition of the above-mentioned combustible gas before the above-mentioned ignition device performs ignition based on the detection result of the above-mentioned flame generation period detection sensor.

[0012] Effects of the Invention

[0013] According to the shock wave generating device of the present disclosure, it is possible to determine the combustion state of fuel. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic configuration diagram showing a shock wave generating device according to a first embodiment.

[0015] Figure 2 A cross-sectional view showing the mounting structure of the optical sensor.

[0016] Figure 3 It is a cross-sectional view showing a modified example of the mounting structure of the optical sensor.

[0017] Figure 4 This is a time chart for explaining the detection method of detonation, deflagration, and flashback.

[0018] Figure 5 This is a flowchart showing a method for determining the combustion state of fuel by a shock wave generating device.

[0019] Figure 6 This is a schematic diagram for explaining the detonation intensity in the shock wave generating device according to the second embodiment.

[0020] Figure 7 It is a schematic configuration diagram showing a shock wave generating device according to a third embodiment.

[0021] Figure 8 This is a time chart for explaining the detection method of detonation, deflagration, and flashback. DETAILED DESCRIPTION

[0022] Hereinafter, the preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In addition, the present disclosure is not limited to the embodiments, and in the case where there are multiple embodiments, a structure formed by combining the embodiments is also included. In addition, the constituent elements in the embodiments include elements that can be easily thought of by those skilled in the art, substantially the same elements, and so-called elements of equivalent scope.

[0023] [First embodiment]

[0024] <Shock wave generating device>

[0025] Figure 1 It is a schematic configuration diagram showing a shock wave generating device according to a first embodiment.

[0026] like Figure 1 As shown, the shock wave generating device 10 of the first embodiment is applied to a dust removal device for removing dust adhering to the inner wall surface of the furnace and the outer surface of the heat transfer tube of a waste incinerator, a coal gasification combined power generation device, a power generation boiler (hereinafter referred to as a boiler), etc. In addition, the furnace is composed of a wall portion surrounding the combustion field of the boiler, but the dust removal device can remove dust adhering to the inner wall surface of the wall portion continuous with the upper and lower parts of the furnace. The dust removal device supplies combustible gas into the furnace through a pipe connected to the inside of the furnace, and generates a shock wave S caused by detonation by igniting the combustible gas. That is, when the combustible gas burns, a detonation wave in which the flame and the shock wave are integrated propagates, and propagates as a shock wave at the time when the combustible gas disappears. The dust removal device blows away and removes the attached dust by causing the shock wave S generated by the detonation to act on the inner wall of the furnace and the outer surface of the heat transfer tube.

[0027] The shock wave generating device 10 is provided in the dust removing device, and generates the shock wave S by the detonation caused by the combustion of the fuel when the dust removing device is operated while the boiler is stopped.

[0028] The shock wave generating device 10 includes a combustion device 11 , a combustible gas supply device 12 , an ignition device 13 , a flame generation timing detection sensor 14 , a control device (determination device) 15 , and an alarm device 16 .

[0029] The combustion device 11 has a gas passage 21 for allowing combustion gas to flow from the base end to the front end. The combustion device 11 has a squib 22 and a burner 23. The gas passage 21 is composed of a first passage 24 provided inside the squib 22 and a second passage 25 provided inside the burner 23.

[0030] The detonator 22 is in the shape of a cylinder, with a base end 22a closed and a front end 22b open. The detonator 22 is provided with a first passage 24 of a predetermined length inside. The detonator 22 is connected to the combustible gas supply device 12 at the base end 22a. The burner 23 is in the shape of a cylinder, with a base end 23a connected and communicated with the front end 22b of the detonator 22, and the front end 23b is open and provided with an opening 23c. The gas passage 21 of the detonator 22 is concentric with the second passage 25 of the burner 23. However, the gas passage 21 of the detonator 22 and the second passage 25 of the burner 23 may not be concentric, and may be of different shapes. The burner 23 is provided with a second passage 25 of a predetermined length inside. The diameter of the second passage 25 of the burner 23 is larger than the diameter of the first passage 24 of the detonator 22. The second passage 25 of the burner 23 has the same diameter from the base end 23a to the front end 22b, but the front end 22b may be enlarged relative to the base end 23a. An opening 23 c at a front end 23 b of the burner 23 communicates with an internal space 103 defined by a furnace wall 102 of the furnace 101 .

[0031] The combustible gas supply device 12 includes a fuel supply unit 31 and an oxidant supply unit 41. The fuel supply unit 31 supplies fuel F. The oxidant supply unit 41 supplies oxygen or air as an oxidant A. The combustible gas supply device 12 supplies a mixed gas formed by mixing the fuel F supplied by the fuel supply unit 31 and the oxidant A supplied by the oxidant supply unit 41 as a combustible gas M from the base end of the combustion device 11 to the inside.

[0032] The fuel supply unit 31 includes a fuel supply path 32, a fuel cylinder 33, a pressure reducing valve 34, a mass flow controller 35, a safety device 36, a fuel supply valve 37, and a check valve 38. The fuel supply path 32 is connected to the fuel cylinder 33 at the upstream end, and is provided with a pressure reducing valve 34, a mass flow controller 35, a safety device 36, a fuel supply valve 37, and a check valve 38 on the downstream side. The fuel cylinder 33 stores fuel F. The pressure reducing valve 34 reduces the pressure of the fuel F in the fuel cylinder 33 to adjust the pressure of the supplied fuel F. The mass flow controller 35 measures the mass flow rate of the fuel F, compares the measured mass flow rate of the fuel F with a preset value of the fuel F, and adjusts the opening of the flow control valve so that the mass flow rate of the fuel F becomes the set value. The safety device 36 prevents backfire. The fuel supply valve 37 is an on-off valve that supplies fuel F when it is open and stops the supply of fuel F when it is closed. The check valve 38 prevents the fuel F and the combustible gas M from flowing back to the upstream side.

[0033] The oxidant supply unit 41 includes an oxidant supply path 42, an oxidant gas cylinder 43, a pressure reducing valve 44, a mass flow controller 45, a safety device 46, an oxidant supply valve 47, and a check valve 48. The oxidant supply path 42 is connected to the oxidant gas cylinder 43 at the upstream end, and is provided with a pressure reducing valve 44, a mass flow controller 45, a safety device 46, an oxidant supply valve 47, and a check valve 48 on the downstream side. The oxidant gas cylinder 43 stores the oxidant A. The pressure reducing valve 44 reduces the pressure of the oxidant A in the oxidant gas cylinder 43 to adjust the pressure of the supplied oxidant A. The mass flow controller 45 measures the mass flow rate of the oxidant A, compares the measured mass flow rate of the oxidant A with the preset set value of the oxidant A, and adjusts the opening of the flow control valve so that the mass flow rate of the oxidant A becomes the set value. The safety device 46 prevents backfire. The oxidant supply valve 47 is an on-off valve, which supplies the oxidant A when it is opened, and stops the supply of the oxidant A when it is closed. The check valve 48 prevents the oxidant A and the combustible gas M from flowing back toward the upstream side.

[0034] The downstream ends of the fuel supply path 32 and the oxidant supply path 42 are connected to the upstream end of the combustible gas supply path 52 via the cross joint 51, and the downstream end of the combustible gas supply path 52 is connected to the base end 22a of the detonator 22. In addition, the purge gas path 53 is connected to the blower 54 at the upstream end, and the downstream end is connected to the cross joint 51. The purge gas path 53 is provided with a purge gas supply valve 55. The cross joint 51 connects the fuel supply path 32, the oxidant supply path 42, the combustible gas supply path 52 and the purge gas path 53. The blower 54 supplies a purge gas (for example, air or an inert gas, etc.) P to the combustible gas supply path 52. The purge gas supply valve 55 is an on-off valve, which supplies the purge gas P when it is opened, and stops the supply of the purge gas P when it is closed.

[0035] The ignition device 13 ignites the combustible gas M supplied to the squib 22 in the combustion device 11 . The ignition device 13 is provided at the base end 22 a of the squib 22 .

[0036] The flame generation timing detection sensor 14 detects the generation timing of the flame C caused by the combustion of the combustible gas M. The flame generation timing detection sensor 14 is provided at the base end 23a of the burner 23 in the combustion device 11. The flame generation timing detection sensor 14 is arranged from the base end 23a of the burner 23 toward the opening 23c, thereby having a sensor area 14a of a predetermined angle.

[0037] The flame generation period detection sensor 14 is preferably an optical sensor that detects the light emission from the flame C generated by the burner 23. As the optical sensor, an ultraviolet light detection sensor is preferred. The flame radiates electromagnetic waves of wavelengths of infrared light (IR), visible light, and ultraviolet light (UV). However, infrared light and visible light are also emitted from outside the flame C. Therefore, by using an ultraviolet light detection sensor, infrared light or visible light is made insensitive, and ultraviolet light is detected to purely detect the signal of only the flame C. In particular, by selectively detecting ultraviolet light with a shorter wavelength (for example, a wavelength of 100 nm to 315 nm that is difficult to reach the ground as a component of sunlight due to absorption by the atmosphere, and in particular, a solar shielding area of ​​100 nm to 280 nm that hardly reaches the ground), erroneous detection of sunlight is prevented.

[0038] However, the optical sensor is not limited to the ultraviolet light detection sensor, and for example, a photodiode or a phototube may be used as the optical sensor.

[0039] The control device 15 is connected to the ignition device 13 , the flame generation timing detection sensor 14 , the mass flow controller 35 , the fuel supply valve 37 , the mass flow controller 45 , the oxidant supply valve 47 , and the purge gas supply valve 55 .

[0040] The control device 15 can control the ignition timing of the combustible gas M by the ignition device 13. The control device 15 is input with the detection result of the flame generation timing detection sensor 14. The control device 15 can adjust and control the mass flow controller 35 and the mass flow controller 45. The control device 15 can open and close the fuel supply valve 37, the oxidant supply valve 47, and the purge gas supply valve 55.

[0041] In addition, the control device 15 functions as a determination device. That is, the control device 15 determines the self-ignition of the combustible gas M before the ignition device 13 performs ignition based on the detection result of the flame generation time detection sensor 14. In addition, the control device 15 determines detonation and deflagration based on the propagation speed of the flame C detected by the flame generation time detection sensor 14.

[0042] Furthermore, when the control device 15 determines that the combustible gas M is self-igniting, the control device 15 controls the combustible gas supply device 12 to stop supplying the combustible gas M to the combustion device 11. That is, the control device 15 closes the fuel supply valve 37 and the oxidant supply valve 47. Furthermore, when the control device 15 determines that the combustible gas M is self-igniting, the control device 15 supplies the purge gas P to the inside of the combustion device 11. That is, after closing the fuel supply valve 37 and the oxidant supply valve 47, the control device 15 opens the purge gas supply valve 55.

[0043] The control device 15 is connected to the alarm device 16. The control device 15 can control the operation of the alarm device 16. When the control device 15 determines that the combustible gas M is self-ignited or exploded, the alarm device 16 is activated.

[0044] Here, the control device 15 is a controller, and is realized by, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), or the like executing various programs stored in a storage unit using a RAM as a work area.

[0045] <Optical sensor mounting structure>

[0046] Figure 2 It is a cross-sectional view showing the mounting structure of the optical sensor.

[0047] like Figure 2 As shown, the burner 23 is provided with an optical window 62 on the wall portion 61 on the base end 23a side. The optical sensor as the flame generation period detection sensor 14 is arranged on the outer side of the wall portion 61 of the burner 23 in a manner covering the optical window 62. The flame generation period detection sensor 14 sets a sensor area 14a of a predetermined angle via the optical window 62. The flame generation period detection sensor 14 detects light from the flame C through the optical window 62. The optical window 6 has transmittance and can also have a filtering performance of extracting only light of a specific wavelength (for example, ultraviolet light). In addition, the optical window 62 can also ensure visual recognition and cooling performance by providing a mechanism for spraying purge gas on the inner surface.

[0048] In addition, the mounting structure of the optical sensor is not limited to the above-mentioned structure. Figure 3 It is a cross-sectional view showing a modified example of the mounting structure of the optical sensor.

[0049] like Figure 3 As shown, the burner 23 is provided with an optical window 62 on the wall portion 61 on the base end 23a side. The optical sensor as the flame generation timing detection sensor 14 is arranged at a predetermined position separated from the burner 23. An optical fiber 63 is provided between the flame generation timing detection sensor 14 and the optical window 62. One end of the optical fiber 63 is connected to the flame generation timing detection sensor 14, and the other end is installed on the outer side of the wall portion 61 of the burner 23 through the mounting member 64 so as to face the optical window 62. The flame generation timing detection sensor 14 sets a sensor area 14a of a predetermined angle via the optical fiber 63 and the optical window 62. The flame generation timing detection sensor 14 detects the light emission from the flame C through the optical window 62 using the optical fiber 63.

[0050] <Detonation, deflagration, and flashback detection methods>

[0051] Figure 4 This is a time chart for explaining the detection method of detonation, deflagration, and flashback.

[0052] like Figure 1 and Figure 4 As shown, the combustible gas supply device 12 supplies the combustible gas M formed by mixing the fuel and the oxidant through the fuel supply unit 31 and the oxidant supply unit 41 and fills the detonator 22. And, at time t2, the ignition device 13 is operated to ignite the combustible gas M of the detonator 22. Then, the combustible gas M is ignited while flowing in the first passage 24 of the detonator 22, and the flame C burns in a manner that spreads from the base end 22a to the front end 22b. And, when the flame C of the detonator 22 reaches the burner 23, the flame C burns in a manner that spreads from the base end 23a to the front end 23b through the second passage 25, generating a shock wave S generated by the detonation.

[0053] The control device 15 determines detonation, deflagration, and flashback (spontaneous combustion) based on the generation period (propagation speed) of the flame C detected by the flame generation period detection sensor 14. The flame generation period detection sensor 14 is an optical sensor that detects the flame C (for example, ultraviolet light). The pulse of the flame generation period detection sensor 14 becomes ON when the flame C is generated, and becomes OFF when the flame C is extinguished. Therefore, the control device 15 calculates the time of flame C generation from the flame generation (pulse ON) to the flame extinguishment (pulse OFF) detected by the flame generation period detection sensor 14, that is, the pulse length τd. The pulse length τd is inversely proportional to the propagation speed of the flame C. The control device 15 determines the combustion state of the fuel (combustible gas M) based on the pulse length τd during the generation of the flame C (the propagation speed of the flame C).

[0054] When the fuel burns, it becomes deflagration or detonation according to the propagation speed of the flame C. When the propagation speed of the flame C is below the speed of sound, it becomes deflagration, and when the propagation speed of the flame C exceeds the speed of sound, it becomes detonation and generates a shock wave S. When it becomes a detonation, a shock wave S is generated. Here, between deflagration and detonation, a threshold value τt corresponding to the propagation speed of the flame C is set. The threshold value τt corresponding to the propagation speed between deflagration and detonation is, for example, a pulse length corresponding to a propagation speed of 1000m / s. That is, when the calculated pulse length τd is below the threshold value τt, it is a detonation, and when the pulse length τd (the propagation speed of the flame C) exceeds the threshold value τt, it is a deflagration. Generally speaking, the propagation speed of the shock wave S generated by the detonation (the propagation speed of the flame C) is above 1000m / s, so the pulse length τd becomes shorter.

[0055] Therefore, the control device 15 determines that it is a detonation when the pulse length τd is less than the threshold value τt, and determines that it is a deflagration when the pulse length τd (the propagation speed of the flame C) exceeds the threshold value τt. That is, when the pulse becomes ON at time t3 and the pulse becomes OFF at time t4, the control device 15 determines that it is a detonation because the pulse length τd is less than the threshold value τt. On the other hand, when the pulse is ON at time t3 and the pulse is OFF at time t6, the pulse length τd exceeds the threshold value τt, so the control device 15 determines that it is a deflagration.

[0056] In addition, during the operation of the boiler, the combustible gas M filled in the burner 23 may spontaneously ignite due to the heat of the exhaust gas rising in the internal space 103 of the furnace 101. The control device 15 determines the flashback caused by the spontaneous combustion based on the generation time of the flame C detected by the flame generation time detection sensor 14. That is, at time t2, when the ignition device 13 operates to ignite the combustible gas M in the detonator 22, then the combustible gas M is ignited to generate a shock wave S caused by detonation. However, if the combustible gas M filled in the burner 23 spontaneously ignites, the flame generation time detection sensor 14 detects the flame C before the ignition device 13 operates. When the ignition device 13 operates to ignite the combustible gas M at time t2, if flashback (self-ignition) occurs, the pulse becomes ON at time t1 which is time Ta earlier than time t2, and the pulse becomes OFF at time t5. When the pulse turns on at time t1 before time t2 when the ignition device 13 is operated, the control device 15 determines that it is backfire.

[0057] Furthermore, when the control device 15 determines that there is detonation, the combustion device 11 is burning normally, so the control device 15 operates the combustion device 11, the combustible gas supply device 12, and the ignition device 13 through the same control at the next operation timing.

[0058] On the other hand, when the control device 15 determines that it is deflagration, the combustion device 11 is abnormally burning, so the control device 15 operates the combustion device 11, the combustible gas supply device 12, and the ignition device 13 through different controls at the next operation timing. That is, the control device 15 adjusts the mixing ratio of the fuel and the oxidant in the combustible gas M generated by the combustible gas supply device 12, for example.

[0059] When the control device 15 determines that flashback occurs, the combustor 11 is abnormally combusting, so the control device 15 stops the combustible gas supply device 12 from supplying the combustible gas M to the combustor 11. Furthermore, the control device 15 supplies the purge gas P to the combustor 11 to suppress the progress of flashback.

[0060] <Method for judging the combustion state of fuel>

[0061] Figure 5 This is a flowchart showing a method for determining the combustion state of fuel by a shock wave generating device.

[0062] like Figure 1 and Figure 5 As shown, in step S11, the control device 15 closes the purge gas supply valve 55 to stop supplying the purge gas P to the combustion device 11. In step S12, the control device 15 opens the fuel supply valve 37 to start supplying the fuel F, and opens the oxidant supply valve 47 to start supplying the oxidant A. Thus, the combustible gas M formed by mixing the fuel F and the oxidant A is supplied to the detonator 22 of the combustion device 11.

[0063] In step S13, the control device 15 determines whether the flame generation period detection sensor 14 detects a pulse (ON) generated along with the flame generation. Here, when the control device 15 determines that the flame generation period detection sensor 14 detects a pulse (ON) (yes), in step S14, the control device 15 determines that flashback has occurred, and in step S15, it is determined that the combustion device 11 is abnormally burned. That is, although the flame generation period detection sensor 14 detects the flame C generated by the burner 23 before the ignition device 13 is operated, the control device 15 determines that it is abnormal combustion with flashback. And, in step S16, the alarm device 16 is operated. In step S17, the supply of the combustible gas M to the combustion device 11 is stopped, and in step S18, the purge gas P is supplied to the combustion device 11.

[0064] On the other hand, in step S13, when the control device 15 determines that the flame generation period detection sensor 14 does not detect a pulse (ON) (No), it moves to step S19. In step S19, the control device 15 determines whether a predetermined elapsed time set in advance has passed since the combustible gas M was supplied to the detonator 22. Here, the elapsed time refers to the time until a predetermined amount of combustible gas M is filled into the detonator 22 and the burner 23 in the combustion device 11. When the control device 15 determines that the predetermined elapsed time has not passed (No), it returns to step S13.

[0065] On the other hand, when the control device 15 determines that the predetermined elapsed time has passed (Yes), in step S20, the control device 15 closes the fuel supply valve 37 to stop the supply of fuel F, and closes the oxidant supply valve 47 to stop the supply of oxidant A. As a result, the supply of the combustible gas M to the detonator 22 of the combustion device 11 is stopped. And, in step S21, the control device 15 operates the ignition device 13 to ignite the combustible gas M filled in the detonator 22. As a result, the combustible gas M is ignited while flowing in the first passage 24 of the detonator 22, and the flame C burns in a manner that spreads from the base end 22a to the front end 22b. And, when the flame C of the detonator 22 reaches the burner 23, the flame C burns in a manner that spreads from the base end 23a to the front end 23b through the second passage 25.

[0066] In step S22, the control device 15 determines whether the flame generation period detection sensor 14 detects a pulse (ON) generated with the flame generation. Here, when the control device 15 determines that the flame generation period detection sensor 14 does not detect a pulse (ON) (No), in step S31, the control device 15 determines whether a predetermined waiting time has passed since the ignition device 13 was activated. Here, when the control device 15 determines that the waiting time has not passed (No), it remains on standby. However, when the control device 15 determines that the waiting time has passed (Yes), in step S32, the control device 15 infers that the ignition device 13 has failed to ignite the combustible gas M, and in step S33, the alarm device 16 is activated.

[0067] On the other hand, when the control device 15 determines that the flame generation period detection sensor 14 detects a pulse (ON) (Yes), the control device 15 determines whether the detected pulse length τd is less than the threshold value τt in step S23. Here, when the control device 15 determines that the detected pulse length τd is not less than the threshold value τt (No), the control device 15 determines that deflagration has occurred in step S24, and determines that it is abnormal combustion of the combustion device 11 in step S25. And, in step S26, the alarm device 16 is activated. In step S27, the mixing ratio of the fuel F and the oxidant A in the combustible gas M supplied to the combustion device 11 is adjusted.

[0068] On the other hand, when the control device 15 determines in step S23 that the detected pulse length τd is less than the threshold τt (Yes), the control device 15 determines in step S28 that detonation has occurred, and determines in step S29 that the combustion device 11 is burning normally.

[0069] [Second embodiment]

[0070] Figure 6FIG. 2 is a schematic diagram for explaining the detonation intensity in the shock wave generating device of the second embodiment. The basic structure of the second embodiment is the same as that of the first embodiment described above. Figure 1 In the following description, components having the same functions as those in the first embodiment described above are denoted by the same reference numerals and detailed description thereof will be omitted.

[0071] like Figure 1 As shown, the shock wave generating device 10 includes a combustion device 11 , a combustible gas supply device 12 , an ignition device 13 , a flame generation timing detection sensor 14 , a control device (determination device) 15 , and an alarm device 16 .

[0072] The control device 15 functions as a determination device, and determines detonation, deflagration, and flashback (spontaneous combustion) based on the detection result of the flame generation period detection sensor 14. Furthermore, when the control device 15 determines that it is detonation based on the detection result of the flame generation period detection sensor 14, it estimates the intensity of the detonation wave based on the propagation speed of the flame.

[0073] The detonation intensity is estimated based on the generation time of the flame C generated in the burner 23, that is, the pulse length τd from when the flame generation period detection sensor 14 detects the flame C and the pulse becomes ON to when the pulse becomes OFF. That is, the detonation intensity of the flame changes according to the filling amount of the combustible gas M supplied to the burner 23. Therefore, it can be estimated that the pulse length τd is less than the threshold value τt and the longer the pulse length τd, the higher the detonation intensity.

[0074] like Figure 6 As shown, in the judgment of detonation, when the pulse length τd defined as the shock wave S (flame) is less than the threshold τt, the maximum shock wave with the highest intensity is when the pulse length τd=threshold τt. For example, when the pulse length τd is a pulse length τd1 shorter than 1 / 2 of the threshold τt, the intensity of the first shock wave is low. On the other hand, when the pulse length τd is a pulse length τd2 longer than 1 / 2 of the threshold τt, the intensity of the second shock wave is high. In addition, the threshold τt is set in consideration of a margin.

[0075] like Figure 1 As shown, the control device 15 controls the combustible gas supply device 12 based on the intensity of the detonation wave (shock wave S) estimated from the pulse length τd of the shock wave S. For example, the control device 15 increases or decreases the filling amount of the combustible gas M relative to the combustion device 11, or adjusts the mixing ratio of the fuel F and the oxidant A in the combustible gas M based on the intensity of the detonation wave (shock wave S). Therefore, the intensity of the shock wave S can be set to the optimal intensity corresponding to the volume of the furnace 101.

[0076] [Third Embodiment]

[0077] Figure 7 1 is a schematic diagram showing the structure of a shock wave generating device according to a third embodiment. Components having the same functions as those of the first embodiment described above are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0078] like Figure 7 As shown, the shock wave generating device 10A includes a combustion device 11, a combustible gas supply device 12, an ignition device 13, flame generation period detection sensors 14A and 14B, a control device (determination device) 15, and an alarm device 16. The combustion device 11, the combustible gas supply device 12, the ignition device 13, the control device 15, and the alarm device 16 are substantially the same in structure as those of the first embodiment.

[0079] The first flame generation timing detection sensor 14A and the second flame generation timing detection sensor 14B detect the generation timing of the flame C caused by the combustion of the combustible gas M. A plurality of the flame generation timing detection sensors 14A and the second flame generation timing detection sensor 14B (two in the present embodiment) are arranged at intervals in the gas flow direction of the burner 23 in the combustion device 11. The flame generation timing detection sensor 14A and the second flame generation timing detection sensor 14B are arranged in a direction intersecting with the flow direction of the combustible gas M or the flame C (shock wave S) in the second passage 25 of the burner 23. The flame generation timing detection sensor 14A is arranged on the upstream side of the second passage 25, and the second flame generation timing detection sensor 14B is arranged on the upstream side of the second passage 25. The first flame generation timing detection sensor 14A and the second flame generation timing detection sensor 14B detect flames at two different locations in the gas flow direction in the second passage 25 of the burner 23. The first flame generation timing detection sensor 14A and the second flame generation timing detection sensor 14B are optical sensors that detect light emission from the flame C generated by the burner 23, and the detection method is the same as that of the first embodiment.

[0080] Figure 8 This is a time chart for explaining the detection method of detonation, deflagration, and flashback.

[0081] like Figure 7 and Figure 8As shown, the combustible gas supply device 12 supplies the combustible gas M formed by mixing the fuel and the oxidant through the fuel supply unit 31 and the oxidant supply unit 41 and fills the detonator 22. Then, at time t2, the ignition device 13 operates to ignite the combustible gas M in the detonator 22. Thus, the combustible gas M is ignited while flowing in the first passage 24 of the detonator 22, and the flame C burns in a manner that spreads from the base end 22a to the front end 22b. And, when the flame C of the detonator 22 reaches the burner 23, the flame C burns in a manner that spreads from the base end 23a to the front end 23b through the second passage 25, generating a shock wave S generated by detonation.

[0082] The control device 15 determines detonation, deflagration, and flashback (spontaneous combustion) based on the generation period (propagation speed) of the flame C detected by the first flame generation period detection sensor 14A and the second flame generation period detection sensor 14B. The first flame generation period detection sensor 14A and the second flame generation period detection sensor 14B are optical sensors that detect flame C (for example, ultraviolet light). The pulse of the first flame generation period detection sensor 14A and the second flame generation period detection sensor 14B becomes ON when the flame C is generated, and the pulse becomes OFF when the flame C is extinguished. When the fuel burns, it becomes deflagration or detonation according to the propagation speed of the flame C. When the propagation speed of the flame C is below the speed of sound, it becomes deflagration, and when the propagation speed of the flame C exceeds the speed of sound, it becomes detonation and generates a shock wave S.

[0083] The first flame generation period detection sensor 14A and the second flame generation period detection sensor 14B are arranged at a distance L in the gas flow direction of the second passage 25. Therefore, a time difference Δt is generated between the detection period (pulse ON) of the flame detected by the first flame generation period detection sensor 14A and the detection period (pulse ON) of the flame detected by the second flame generation period detection sensor 14B. The time difference Δt is inversely proportional to the propagation speed of the flame C. The control device 15 determines the combustion state of the fuel (combustible gas M) based on the time difference Δt of the shock wave S (the propagation speed of the flame C).

[0084] Here, a threshold value Vt of the propagation speed of the flame C is set between deflagration and detonation. The threshold value Vt of the propagation speed between deflagration and detonation is, for example, a propagation speed of 1000 m / s. That is, when the propagation speed L / Δt calculated from the distance L and the calculated time difference Δt is greater than the threshold value Vt, it is detonation, and when the propagation speed L / Δt is less than the threshold value Vt, it is deflagration.

[0085] Therefore, the control device 15 determines that it is a detonation when the propagation speed L / Δt is greater than the threshold value Vt, and determines that it is a deflagration when the propagation speed L / Δt is less than the threshold value Vt. That is, if the pulse of the detection sensor 14A during the first flame generation period turns on at time t3, and the pulse of the detection sensor 14B during the second flame generation period turns on at time t4, the time difference Δt1 is short, and the propagation speed L / Δt1 is greater than the threshold value Vt, so the control device 15 determines that it is a detonation. On the other hand, if the pulse of the detection sensor 14A during the first flame generation period turns on at time t3, and the pulse of the detection sensor 14B during the second flame generation period turns on at time t5, the time difference Δt2 is long, and the propagation speed L / Δt2 is less than the threshold value Vt, so the control device 15 determines that it is a deflagration.

[0086] In addition, during the operation of the boiler, the combustible gas M filled in the burner 23 may spontaneously ignite due to the heat of the exhaust gas rising in the internal space 103 of the furnace 101. The control device 15 determines the flashback caused by the spontaneous combustion based on the generation time of the flame C detected by the first flame generation time detection sensor 14A or the second flame generation time detection sensor 14B. That is, at time t2, when the ignition device 13 operates to ignite the combustible gas M in the detonator 22, then the combustible gas M is ignited to generate a shock wave S generated by the detonation. However, if the combustible gas M filled in the burner 23 spontaneously ignites, the flame generation time detection sensors 14 and 14B detect the flame C before the ignition device 13 operates. When the ignition device 13 operates to ignite the combustible gas M at time t2, if flashback (spontaneous combustion) occurs, the pulse becomes ON at time t1 which is time Ta earlier than time t2, and the pulse becomes OFF at time t4. When the pulse turns on at time t1 before time t2 when the ignition device 13 is operated, the control device 15 determines that it is backfire.

[0087] The method of determining the combustion state of fuel by the shock wave generating device 10A of the third embodiment is substantially the same as that of the first embodiment, and therefore the description thereof will be omitted.

[0088] In addition, the third embodiment changes the position of the flame generation timing detection sensors 14 and 14B relative to the first embodiment. However, the flame generation timing detection sensors 14 and 14B of the third embodiment may be added to the flame generation timing detection sensor 14 of the first embodiment. In this case, detonation can be determined with higher accuracy.

[0089] [Effects of this embodiment]

[0090] The shock wave generating device of the first mode comprises: a combustion device 11, which is provided with a gas passage 21 for the combustion gas to flow from the base end to the front end and is provided with an opening at the front end; a combustible gas supply device 12, which supplies the combustible gas M from the base end to the inside of the combustion device 11; an ignition device 13, which ignites the combustible gas M supplied to the combustion device 11; flame generation period detection sensors 14, 14A, 14B, which detect the generation period of the flame C caused by the combustion of the combustible gas M; and a control device (determination device) 15, which determines the self-ignition of the combustible gas M before the ignition device 13 performs ignition based on the detection results of the flame generation period detection sensors 14, 14A, 14B.

[0091] According to the shock wave generating device of the first embodiment, the control device 15 determines the self-ignition of the combustible gas M before ignition by the ignition device 13 based on the generation timing of the flame C caused by the combustion of the combustible gas M. As a result, the combustion state of the fuel can be determined.

[0092] The shock wave generating device of the second embodiment is the shock wave generating device of the first embodiment, in which the control device 15 further determines detonation and deflagration based on the propagation speed of the flame C detected by the flame generation timing detection sensor 14. This makes it possible to determine the combustion state of the fuel in detail.

[0093] The shock wave generating device of the third embodiment is based on the shock wave generating device of the second embodiment, and further, when the control device 15 determines that there is a detonation, the intensity of the detonation wave is estimated based on the propagation speed of the flame C. Thus, by estimating the intensity of the detonation wave, the intensity of the detonation wave can be adjusted according to the application object of the shock wave.

[0094] The shock wave generating device of the fourth embodiment is based on any of the shock wave generating devices of the first to third embodiments, and further, the flame generation period detection sensors 14, 14A, 14B are optical sensors for detecting light emission from the flame. Thus, the flame can be easily identified by detecting infrared light, visible light, and ultraviolet light.

[0095] The shock wave generating device of the fifth embodiment is based on any one of the shock wave generating devices of the first to fourth embodiments, and further, the combustion device 11 further comprises: a detonator 22, the base end 22a of which is connected to the combustible gas supply device 12; and a burner 23, the base end 23a of which is connected to the front end 22b of the detonator 22, and the flame generation period detection sensor 14 is arranged toward the opening 23c of the burner 23. Thus, the flame generated by the burner 23 can be easily detected by the flame generation period detection sensor 14.

[0096] The shock wave generating device of the sixth mode is based on any one of the shock wave generating devices of the first mode to the fifth mode, and further, the combustion device 11 further comprises: a detonator 22, the base end 22a of which is connected to the combustible gas supply device 12; and a burner 23, the base end 23a of which is connected to the front end 22b of the detonator 22, and a plurality of flame generation period detection sensors 14A and 14B are arranged in the burner 23 at intervals in the gas flow direction. Thus, the flame generated by the burner 23 can be appropriately detected.

[0097] The shock wave generating device of the seventh aspect is the shock wave generating device of any one of the first to sixth aspects, and further, when the control device 15 determines that the combustible gas M is self-ignited, the combustible gas supply device 12 stops supplying the combustible gas M. This can improve safety.

[0098] The shock wave generating device of the eighth aspect is the shock wave generating device of the seventh aspect, and further supplies the purge gas P into the combustion device 11 when the control device 15 determines that the combustible gas M is self-igniting. This can improve safety.

[0099] In addition, in the above-mentioned embodiment, the shock wave generating device is applied to a dust removal device for removing dust adhering to the inner wall surface of the furnace of a garbage incinerator, a coal gasification combined power generation device, a boiler for power generation, etc. or the outer surface of a heat transfer tube, but the application object is not limited to this. The shock wave generating device can be applied, for example, to a propulsion engine that radiates shock waves from the opening of a combustion device and forms thrust by the reaction force thereof, a power engine that rotates a turbine, a device that radiates shock waves from the opening of a burner and uses the high pressure of the shock waves to exert a physical effect (destruction of structures, separation of materials, etc.) on an object arranged near the opening, a device that uses the high pressure of the shock waves to exert a physical effect (destruction of structures, separation of materials, etc.) on an object arranged inside a combustion device, etc.

[0100] Description of Reference Numerals

[0101] 10.10A shock wave generating device

[0102] 11 Combustion device

[0103] 12 Combustible gas supply device

[0104] 13 Ignition device

[0105] 14 Flame generation period detection sensor

[0106] 14A First flame generation period detection sensor

[0107] 14B Second flame generation period detection sensor

[0108] 15. Control device (determination device)

[0109] 21 Gas passage

[0110] 22 Detonator

[0111] 23 Burner

[0112] 24 First Access

[0113] 25 Second Path

[0114] 31 Fuel supply unit

[0115] 32 Fuel supply path

[0116] 33 Fuel cylinder

[0117] 34 Pressure reducing valve

[0118] 35 Mass Flow Controller

[0119] 36 Safety Device

[0120] 37 Fuel supply valve

[0121] 38 Check valve

[0122] 41 Oxidant supply unit

[0123] 42 Oxidant supply path

[0124] 43 Oxidant Gas Cylinder

[0125] 44 Pressure reducing valve

[0126] 45 Mass Flow Controller

[0127] 46 Safety Device

[0128] 47 Oxidant supply valve

[0129] 48 Check valve

[0130] 51 Cross Connector

[0131] 52 Combustible gas supply path

[0132] 53 Purge gas path

[0133] 54 Blower

[0134] 55 Purge gas supply valve

[0135] 61 Wall

[0136] 62 Optical Window

[0137] 63 Fiber Optic

[0138] 64 Mounting parts

[0139] F Fuel

[0140] A. Oxidant

[0141] M Combustible gas

[0142] C Flame

[0143] S shock wave.

Claims

1. A shock wave generating device, comprising: A combustion device having a gas passage for combustion gas to flow from a base end to a front end and having an opening at the front end; a combustible gas supply device for supplying combustible gas from the base end of the combustion device to the interior; an ignition device for igniting the combustible gas supplied to the combustion device; a flame generation period detection sensor for detecting a generation period of a flame caused by the combustion of the combustible gas; and The determination device determines the spontaneous combustion of the combustible gas before the ignition device performs ignition based on the detection result of the flame generation timing detection sensor.

2. The shock wave generating device according to claim 1, wherein: The determination device determines detonation and deflagration based on a propagation speed of the flame detected by the flame generation period detection sensor.

3. The shock wave generating device according to claim 2, wherein: When the determination device determines that there is a detonation, the intensity of the detonation wave is estimated based on the propagation speed of the flame.

4. The shock wave generating device according to any one of claims 1 to 3, wherein: The flame generation period detection sensor is an optical sensor that detects light emission from the flame.

5. The shock wave generating device according to claim 1, wherein: The combustion device includes: a squib having a combustible gas supply device connected to a base end thereof; and a burner having a base end connected to a front end of the squib, wherein the flame generation timing detection sensor is arranged facing the opening of the burner.

6. The shock wave generating device according to claim 1, wherein: The combustion device comprises: a squib having a combustible gas supply device connected to a base end thereof; and a burner having a base end connected to a front end of the squib, wherein a plurality of flame generation timing detection sensors are arranged in the burner at intervals in a gas flow direction.

7. The shock wave generating device according to claim 1, wherein: When the determination device determines that the combustible gas is self-igniting, the combustible gas supply device stops supplying the combustible gas.

8. The shock wave generating device according to claim 7, wherein: When the determination device determines that the combustible gas is self-igniting, a purge gas is supplied to the interior of the combustion device.

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