WO2020230531A1 - Burner for gas turbine, and method for controlling combustion in same - Google Patents

Burner for gas turbine, and method for controlling combustion in same Download PDF

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Publication number
WO2020230531A1
WO2020230531A1 PCT/JP2020/017011 JP2020017011W WO2020230531A1 WO 2020230531 A1 WO2020230531 A1 WO 2020230531A1 JP 2020017011 W JP2020017011 W JP 2020017011W WO 2020230531 A1 WO2020230531 A1 WO 2020230531A1
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Prior art keywords
pressure
gas turbine
dbd plasma
combustion chamber
plasma actuator
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PCT/JP2020/017011
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French (fr)
Japanese (ja)
Inventor
祐康 志村
謙斗 佐々木
チャクラボルティ シュジョイ
謙治朗 小松
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国立大学法人東京工業大学
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Publication of WO2020230531A1 publication Critical patent/WO2020230531A1/en

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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H1/00—Generating plasma; Handling plasma
    • H05H1/24—Generating plasma
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
    • F02C9/00—Controlling gas-turbine plants; Controlling fuel supply in air- breathing jet-propulsion plants
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
    • F02C9/00—Controlling gas-turbine plants; Controlling fuel supply in air- breathing jet-propulsion plants
    • F02C9/16—Control of working fluid flow
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23R—GENERATING COMBUSTION PRODUCTS OF HIGH PRESSURE OR HIGH VELOCITY, e.g. GAS-TURBINE COMBUSTION CHAMBERS
    • F23R3/00—Continuous combustion chambers using liquid or gaseous fuel
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23R—GENERATING COMBUSTION PRODUCTS OF HIGH PRESSURE OR HIGH VELOCITY, e.g. GAS-TURBINE COMBUSTION CHAMBERS
    • F23R3/00—Continuous combustion chambers using liquid or gaseous fuel
    • F23R3/02—Continuous combustion chambers using liquid or gaseous fuel characterised by the air-flow or gas-flow configuration
    • F23R3/04—Air inlet arrangements
    • F23R3/10—Air inlet arrangements for primary air
    • F23R3/12—Air inlet arrangements for primary air inducing a vortex
    • F23R3/14—Air inlet arrangements for primary air inducing a vortex by using swirl vanes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23R—GENERATING COMBUSTION PRODUCTS OF HIGH PRESSURE OR HIGH VELOCITY, e.g. GAS-TURBINE COMBUSTION CHAMBERS
    • F23R3/00—Continuous combustion chambers using liquid or gaseous fuel
    • F23R3/28—Continuous combustion chambers using liquid or gaseous fuel characterised by the fuel supply

Definitions

  • the present invention relates to a gas turbine combustor and a combustion control method thereof.
  • DBD dielectric barrier discharge
  • Patent Document 1 discloses a jet control device using a coaxial DBD plasma actuator on the jet outlet side of a nozzle. According to Patent Document 1, an induced flow is formed in the flow direction of the main jet by the DBD plasma actuator, and the strength of the induced flow by the DBD plasma is changed by controlling the magnitude and frequency of the voltage applied to the jet control device. , It is said that the degree of diffusion of the jet can be changed freely.
  • Patent Document 1 Even if the technology of Patent Document 1 can be applied to a gas turbine and the degree of jet diffusion can be adjusted by generating DBD plasma, it is not possible to effectively suppress combustion vibration by itself.
  • the present invention pays particular attention to the fact that the combustion vibration generated by gas turbine combustion causes a sudden change in calorific value when a large-scale vortex generated in the shear layer at the inlet of the combustor entrains a flame, and generates a large-scale vortex. It is an object of the present invention to provide a combustor of a gas turbine and a combustion control method for suppressing combustion vibration by controlling the combustion.
  • the combustor of the gas turbine of the present invention is a combustor of a gas turbine including a tubular duct portion having a combustion chamber inside and a supply device for supplying mixed gas from the inlet of the combustion chamber to the combustion chamber. , A pressure sensor that detects the pressure inside the duct and outputs a pressure signal, A DBD plasma actuator with a pair of electrodes located at the inlet of the combustion chamber, A drive circuit that intermittently drives the DBD plasma actuator by inputting a drive signal having a predetermined duty ratio to the electrode based on the pressure signal from the pressure sensor.
  • the driving phase ⁇ d with respect to the reference point exists with the zero point passing when the fluctuation of the pressure waveform changes from negative to positive as the reference point of the phase, and the pressure signal.
  • n is an integer of 0 or more
  • the DBD plasma actuator is intermittently driven after (2n ⁇ + ⁇ d) has elapsed from the input of the pressure signal.
  • the predetermined drive phase ⁇ d is 0 or more and ⁇ or less, or 7 ⁇ / 4 or more and 2 ⁇ or less.
  • the method of controlling the combustor of the gas turbine of the present invention includes a tubular duct portion whose inside is a combustion chamber, a supply device for supplying mixed gas from the inlet of the combustion chamber to the combustion chamber, and the combustion chamber.
  • a combustion control method for a gas turbine combustor equipped with a DBD plasma actuator with a pair of electrodes located at the inlet The pressure in the duct portion is detected, a pressure signal is output, and the pressure signal is output. Based on the pressure signal, a drive signal having a predetermined duty ratio is input to the electrode.
  • the driving phase ⁇ d with respect to the reference point exists with the zero point passing when the fluctuation of the pressure waveform changes from negative to positive as the reference point of the phase, and the pressure signal.
  • one cycle of the pressure waveform corresponding to is 2 ⁇ and n is an integer of 0 or more
  • the DBD plasma actuator is intermittently driven after (2n ⁇ + ⁇ d) has elapsed from the input of the pressure signal.
  • the predetermined drive phase ⁇ d is 0 or more and ⁇ or less, or 7 ⁇ / 4 or more and 2 ⁇ or less.
  • a combustor of a gas turbine that suppresses combustion vibration by controlling the generation of a large-scale vortex and a combustion control method thereof.
  • FIG. 1 is a schematic view of a gas turbine including a combustor according to an embodiment of the present invention.
  • FIG. 2 is a cross-sectional view of the combustor according to the present embodiment.
  • FIG. 3 is an exploded view showing a schematic structure of the supply device 140.
  • FIG. 4A is an axial sectional view of the DBD plasma actuator, and
  • FIG. 4B is a top view of the DBD plasma actuator.
  • FIG. 5 is a perspective view of the DBD plasma actuator ACT being driven.
  • FIG. 6 is a schematic diagram of a drive circuit that drives the DBD plasma actuator.
  • FIG. 7 is a block diagram of a drive circuit capable of executing the active control method of the DBD plasma actuator of the present embodiment.
  • FIG. 8A is a diagram showing an example of the waveform of the pressure signal of the pressure sensor 146 input to the FIR filter of the controller board CB
  • FIG. 8B is a diagram input to the FIR filter and processed. It is a figure which shows the latter waveform.
  • Figure 9 is a diagram showing side by side with the pressure waveform p 'as an example to be input to the controller board CB, and a waveform V in the drive signal output from the function generator FG in response to a trigger signal from the controller board CB .
  • FIG. 10 is a cross-sectional view showing the vicinity of the inlet of the combustion chamber of the duct portion.
  • FIG. 11 (a) to 11 (h) show the average radial velocity of the gas flow induced when the DBD plasma actuator is intermittently driven at 50 Hz to 120 Hz in the state where there is no gas inflow into the combustion chamber. It is a figure which shows the distribution.
  • FIG. 12 is a cross-sectional view showing the vicinity of the inlet of the combustion chamber of the duct portion.
  • RMS root mean square
  • FIG. 1 is a schematic view of a gas turbine including a combustor according to an embodiment of the present invention.
  • the compressor 11 sucks air 12 to generate compressed air.
  • the compressed air is sufficiently mixed with the fuel (here, methane gas) to form an air-fuel mixture 13, and the air-fuel mixture 13 is burned in the combustor 14 to generate a high-temperature and high-pressure combustion gas 16.
  • the combustion gas 16 is supplied to the turbine 17 and used for the rotation of the rotor 18.
  • the rotation of the rotor 18 is transmitted to the compressor 11 and used to generate the compressed gas 13. Further, the rotation of the rotor 18 is transmitted to, for example, the generator 19 and used for power generation.
  • FIG. 2 is a cross-sectional view of the combustor 14.
  • the axis of the combustor extends in the vertical direction, with the lower part being the compressor side and the upper part being the turbine side.
  • the combustor 14 is formed by connecting a supply device 140 on the compressor side and a duct portion 145 on the turbine side.
  • the total length of the duct portion 145 is 1175 mm, but the total length is not limited to that.
  • the pressure sensor 146 is attached at a position 450 mm from the end portion on the side of the supply device.
  • the inside of the duct portion 145 becomes a combustion chamber.
  • FIG. 3 is an exploded view showing a schematic structure of the supply device 140.
  • the supply device 140 has a nozzle portion 141a connected to the duct portion 145 and a swirler 141b incorporated in the nozzle portion 141a at a position 100 mm upstream from the inlet of the combustion chamber.
  • the nozzle portion 141a has a hollow cylindrical outer wall portion 141c, a central cylindrical rectifying portion 141d, and a flange portion 141e extending in the radial direction from the outer wall portion 141c.
  • the space between the outer wall portion 141c and the rectifying portion 141d serves as the flow path FP for the compressed gas.
  • the outlet of the flow path FP at the connecting portion between the duct portion 145 and the nozzle portion 141a serves as the combustion chamber inlet.
  • the end of the rectifying section 141d on the duct section side has a truncated cone shape with a larger diameter toward the duct section, whereby the flow path FP of the compressed gas is throttled at the outlet.
  • the outer diameter of the rectifying portion 141d is 15 mm
  • the inner diameter of the outer wall portion 141c is 30 mm, but the present invention is not limited to this.
  • the double-cylindrical swirler 141b is provided with a plurality of blades 141f that are spirally curved at a predetermined swirl angle, and has a function of imparting a swirling flow to the compressed gas passing through the flow path FP.
  • the compressed gas ejected from the outlet of the flow path FP into the combustion chamber is ignited by an ignition plug (not shown) and burned, and the combustion gas is discharged from the end of the duct portion 145.
  • a DBD plasma actuator ACT is assembled on the upper surface of the flange portion 141e so as to surround the outlet of the compressed gas flow path FP.
  • FIG. 4A is an axial sectional view of the DBD plasma actuator
  • FIG. 4B is a top view of the DBD plasma actuator.
  • the annular upper electrode EL1 (here, a 70 ⁇ m copper plate) is coaxially arranged on the upper surface of the dielectric LL (here, a 500 ⁇ m thick alumina plate) of the annular plate.
  • an annular lower electrode EL2 (here, a 70 ⁇ m copper plate) is coaxially arranged on the lower surface of the dielectric LL.
  • the shift arrangement is made so that the inner diameter of the upper electrode EL1 matches the outer diameter of the lower electrode EL2.
  • the upper electrode EL1 and the lower electrode EL2 are connected to a drive circuit described later.
  • the outer diameter of the dielectric LL is 60 mm
  • the outer diameter of the upper electrode EL1 is 50 mm
  • the inner diameter of the upper electrode EL1 and the outer diameter of the lower electrode EL2 are 40 mm
  • the inner diameter of the lower electrode EL2 and the inner diameter of the dielectric LL. Is 30 mm, but is not limited to this. It should be noted that even if the DBD plasma actuator includes two or more pairs of electrodes, it can be used as long as it has the effect of inducing flow as described later. For example, the same effect can be obtained by combining two pairs of semicircular electrodes to form a pair of circular electrodes.
  • FIG. 5 is a perspective view of the DBD plasma actuator ACT being driven.
  • the annular range indicated by the symbol PM indicates light emission (blue-purple light) due to the generation of plasma, and the radial flow toward the central axis of the combustor is induced by operating the DBD plasma actuator ACT. You can see that.
  • FIG. 6 is a schematic view of the drive circuit DR1 that drives the DBD plasma actuator.
  • the high-frequency sine wave generated by the function generator FG is voltage-amplified via the power amplifier AMP and the transformer TR, and the generated high-frequency high-voltage signal is input to the electrodes EL1 and EL2 of the DBD plasma actuator ACT to be centripetal. Flow can be generated.
  • the drive circuit DR1 is installed separately from the supply device 140.
  • FIG. 7 is a block diagram of the drive circuit DR2 capable of executing the active control method of the DBD plasma actuator of the present embodiment.
  • the main difference is that the drive circuit DR1 of FIG. 6 is provided with a means for inputting a trigger signal to the function generator FG.
  • the pressure sensor 146 (manufactured by Kistler, trade name 7061C) provided in the duct portion 145 detects the pressure fluctuation in the combustion chamber and outputs a pressure signal corresponding to the pressure fluctuation.
  • a power amplifier AMP manufactured by Kistler, trade name Type5018
  • a high frequency is cut by an antialiasing filter AAF (manufactured by NF circuit block, trade name DT Filter3344), and further, a controller board CB (dSPACE).
  • the sampling process is performed with the product name DS1104) manufactured by the company.
  • a finite impulse response (FIR) filter removes high-frequency components of 200 Hz or higher (however, it is determined depending on the frequency of combustion vibration), and the data for the past 1 second is collected.
  • the pressure fluctuation is calculated by taking the difference from the average.
  • the trigger signal including the waveform data related to the pressure fluctuation is input from the controller board CB to the function generator FG (manufactured by Sony Tektronix, trade name AFG320).
  • FIG. 8A shows an example of the waveform of the pressure signal of the pressure sensor 146 input to the FIR filter in the controller board CB, and it can be seen that high frequency noise is superimposed. By inputting this into the FIR filter and processing it, data of a smooth periodic waveform as shown in FIG. 8B can be obtained.
  • the controller board CB into which the waveform data is input transmits a trigger signal to the function generator FG, and transmits a drive signal from the function generator FG to the DBD plasma actuator ACT.
  • the input voltage, input frequency, drive phase, and intermittent drive duty ratio are input to the function generator FG in advance, and the drive phase uses the values input to the controller board CB in advance.
  • the point at which the pressure fluctuation changes from negative to positive is defined as the phase reference point
  • the difference between the pressure fluctuation and the drive start of the DBD plasma actuator ACT is defined as the drive phase ( ⁇ d) based on the pressure fluctuation phase.
  • Figure 9 is a diagram showing side by side with the pressure waveform p 'as an example to be input to the controller board CB, and a waveform V in the drive signal output from the function generator FG in response to a trigger signal from the controller board CB .
  • the frequency of the drive signal can be changed arbitrarily.
  • a rectifying unit 141d with an outer diameter of 10 mm was mounted on the central axis of the outer wall portion 141c so that the outer diameter expanded to 15 mm toward the inlet of the combustion chamber.
  • the combustion chamber is a prism with a cross section of 120 mm x 120 mm and a length of 1175 mm. As shown in FIG. 10, the vicinity of the entrance of the combustion chamber of the duct portion 145 is surrounded on all sides by quartz glass GL, and optical measurement in the combustion chamber is possible from the outside.
  • the present inventors conducted a comparative test by driving the DBD plasma actuator under different conditions.
  • the DBD plasma actuator is driven by using a sine wave signal with an input frequency of 10 kHz and an input voltage of 1 Vpp generated by the function generator FG as a power amplifier AMP (manufactured by Classic Pro, trade name CP500X).
  • the voltage was amplified about 8000 times by a transformer and input to the electrodes of the DBD plasma actuator.
  • Plasma is generated in response to changes in the sine wave, but it is assumed that the DBD plasma actuator is operating during the period when the drive signal is being input, and intermittent drive is realized by repeating on / off of the input signal. ..
  • 11 (a) to 11 (h) show the average distribution of the radial velocity of the gas flow induced when the DBD plasma actuator is intermittently driven at 50 Hz to 120 Hz in the state where there is no gas inflow into the combustion chamber.
  • the duty ratio of the intermittent drive on / off is set to 50%.
  • the velocity of the gas was measured by a stereo particle image velocimetry, and the size of the inspection area when calculating the velocity was 480 ⁇ m ⁇ 480 ⁇ m, and the thickness of the laser sheet was 800 ⁇ m.
  • the measured area is 24 mm ⁇ 24 mm with the central axis of the combustor (rectifying unit 141d) as one side of the measurement area, and the right end of each distribution is the end of the upper electrode of the DBD plasma actuator.
  • the radial velocity distribution induced by the intermittent drive frequency was slightly different, and an increase in the velocity of the gas toward the central axis of the combustor was observed on the DBD plasma actuator as the frequency increased.
  • the average radial velocity of the gas from the vicinity of the outer circumference of the combustion chamber inlet to the central axis of the combustor is about 1 m / s regardless of the frequency of intermittent drive. In the intermittent driving, remarkable fluctuations in the flow velocity were observed at that frequency.
  • the present inventors confirmed the effect of performing active control using the signal of the pressure sensor that detects the pressure in the firing chamber as an input, and performing intermittent drive in relation to the pressure fluctuation of the DBD plasma actuator.
  • the drive timing of the DBD plasma actuator was controlled by the drive circuit DR2 shown in FIG.
  • the intermittent drive of the DBD plasma actuator will start after a certain period of time from the point that serves as the reference for pressure fluctuations.
  • the zero point that passes when the pressure fluctuation (pressure waveform) changes from negative to positive is set as the phase reference point, and the DBD plasma actuator drives the reference point.
  • the difference (deviation) until the start is defined as the drive phase ⁇ d based on the phase of the pressure fluctuation.
  • the delay from the trigger signal input to the function generator FG to the drive of the DBD plasma actuator is measured in advance, and the drive phase ⁇ d is determined in consideration of this delay. Since the phase of the pressure fluctuation signal is delayed by applying the FIR filter, the drive signal is transmitted with the phase shifted by (2n ⁇ + ⁇ d) from the reference point to drive the DBD plasma actuator (Fig. 9). .. However, n is an integer of 0 or more.
  • OH self-luminous is an ultraviolet compatible lens (Nikon, trade name UV) equipped with a bandpass filter (Semrock, trade name FF01-320 / 40-50-D) with a center wavelength of 320 nm and a half-price width of 43.8 nm. -105mmF4.5) focused, amplified by an image intensifier (Hamamatsu Photonics, trade name C10880-03F), and photographed by a high-speed CMOS camera (Photron, trade name SA-X2). .
  • a delay pulse pulse generator (manufactured by Berkeley Nucleonics, trade name MODEL 575 PULSE DELAY GENERATOR) was used to synchronize the camera and image intensifier.
  • the pressure fluctuation measurement in the combustor was performed by acquiring the data from the pressure sensor / amplifier used for control with an A / D board (manufactured by National Instruments, trade name PCI-6115).
  • the conditions were set to an equivalent ratio of 0.65 and a flow rate of 250 L / min, where weak vibration combustion occurs in a swirl type combustor.
  • the input signal to the DBD plasma actuator was a sine wave with an input frequency of 10 kHz and an input voltage of 8.6 kVpp.
  • the area indicated by the frame FR in FIG. 10 is the OH self-luminous photographing area.
  • OH self-luminous measurement was performed in a range of 117 mm ⁇ 117 mm directly above the inlet of the combustion chamber surrounded by the frame FR.
  • the gain of the image intensifier was 860
  • the gate width was 80 ⁇ s
  • the shooting speed was 10 kHz.
  • the measurement speed of pressure fluctuation was set to 20 kHz. These measurement times were set to about 2.2 seconds.
  • FIG. 13 shows the distribution of the average value of OH self-luminous intensity.
  • the distribution of the average OH self-luminous intensity is normalized by the average OH self-luminous intensity, which is the maximum under all conditions.
  • FIG. 14 shows the distribution of the root mean square (RMS) of the OH self-luminous intensity fluctuation.
  • RMS root mean square
  • the peak frequency is about 67Hz, and the second peak is observed near about 75Hz.
  • the average value Irms is shown.
  • the horizontal solid line and horizontal dotted line in the figure show the RMS value under the condition that the DBD plasma actuator is not driven (actuator not used).
  • the pressure fluctuation frequency changes depending on the combustion temperature
  • the pressure fluctuation in the combustor is based on the signal of the pressure sensor installed in the combustion duct by installing the DBD plasma actuator on the outer circumference of the combustion inlet. It was found that the combustion vibration can be actively suppressed by giving a phase difference within a predetermined range to induce a flow that intersects the mainstream in the outer shear layer.
  • FIG. 17 shows the pressure fluctuation RMS value p'rms and the DBD plasma actuator when the duty ratio of the intermittent drive in the DBD plasma actuator is changed to (a) 30%, (b) 50%, and (c) 70%. It is a figure which shows the relationship with the drive phase of.
  • the duty ratio of 30% means that the on time is 0.3T and the off time is 0.7T, where T is the time of one cycle of on / off.
  • the conditions were set to an equivalent ratio of 0.66 and a flow rate of 250 L / min, in which weak vibration combustion occurs in a swirl-type combustor.
  • the input signal to the DBD plasma actuator was a sine wave with an input frequency of 10 kHz and an input voltage of 8.6 kVpp.
  • the measurement speed of pressure fluctuation was set to 20 kHz. These measurement times were set to about 10 seconds.
  • the range of the drive phase ⁇ d is also expanded. It is effective when the drive phase ⁇ d is 0 or more and ⁇ or less, or 7 ⁇ / 4 or more and 2 ⁇ or less.
  • the DBD plasma actuator was intermittently driven, active control was performed using the pressure sensor signal as an input, and the effect of the drive phase of the DBD plasma actuator on the combustion characteristics was examined.
  • Got (1) By intermittently driving the DBD plasma actuator and appropriately selecting the drive phase, it is possible to suppress pressure fluctuations and OH self-luminous intensity fluctuations.
  • By effective control of the DBD plasma actuator By effective control of the DBD plasma actuator, the flame spreads to the downstream side and the fluctuation region narrows in the radial direction.
  • Effective control of the DBD plasma actuator reduces the peak frequency of the power spectrum of pressure fluctuations.

Abstract

The present invention provides: a burner for a gas turbine in which the occurrence of large-scale vortices is controlled, whereby combustion oscillation is suppressed; and a method for controlling combustion in the burner.　A burner for a gas turbine provided with a cylindrical duct part in which the interior is a combustion chamber, and a feeding device for feeding a mixture gas from the inlet of the combustion chamber into the combustion chamber, the burner having: a pressure sensor for detecting the pressure in the duct part and outputting a pressure signal; a DBD plasma actuator disposed at the inlet of the combustion chamber, the DBD plasma actuator being provided with a pair of electrodes; and a drive circuit for transmitting a drive signal to the electrodes on the basis of the pressure signal from the pressure sensor, and thereby intermittently driving the DBD plasma actuator. When the average of a pressure waveform is deemed to be a zero point, the zero point that the variation of the pressure waveform passes through when turning from negative to positive is deemed to be the phase reference point, a drive phase θd with respect to the reference point is deemed to be present, one period of the pressure waveform corresponding to the pressure signal is ２π, and n is an integer equal to or greater than zero, the DBD plasma actuator is intermittently driven after (2nπ ＋ θd) has elapsed from the input of the pressure signal, and the prescribed drive phase θd is 0 to π inclusive or 7π/4 to 2π inclusive.

Description

ガスタービンの燃焼器及びその燃焼制御方法Gas turbine combustor and its combustion control method
　本発明は、ガスタービンの燃焼器及びその燃焼制御方法に関する。 The present invention relates to a gas turbine combustor and a combustion control method thereof.
　近年、注目されている環境・エネルギー問題を解決するために，高効率・低環境負荷のガスタービン燃焼器の開発が求められている。ガスタービンの熱効率向上やＮＯｘ生成の抑制には旋回乱流希薄予混合燃焼が有効であるが，燃焼振動が発生しやすく，それにより燃焼器の破壊や逆火を招く恐れがある。 In recent years, in order to solve the environmental and energy problems that have been attracting attention, the development of a gas turbine combustor with high efficiency and low environmental load is required. Swirling turbulent lean premixed combustion is effective for improving the thermal efficiency of gas turbines and suppressing NOx generation, but combustion vibration is likely to occur, which may lead to combustor destruction or flashback.
　これまで燃焼器の燃焼振動を抑制する方法として，燃料や空気やそれらの混合物の噴射条件や音響場を与えることが試みられてきた。また，流動を誘起する装置として近年では誘電体バリア放電（DBD）プラズマアクチュエータが流体力学分野で盛んに研究されている。 Until now, as a method of suppressing the combustion vibration of the combustor, it has been attempted to provide the injection conditions and acoustic field of fuel, air, and a mixture thereof. In recent years, dielectric barrier discharge (DBD) plasma actuators have been actively studied in the field of fluid dynamics as a device for inducing flow.
　例えば特許文献１には、同軸型のDBDプラズマアクチュエータをノズルの噴流出口側に用いた噴流制御装置が開示されている。特許文献１によれば、DBDプラズマアクチュエータにより誘起流れが主噴流の流れ方向に形成され、噴流制御装置に印加する電圧の大きさ、周波数制御によりDBDプラズマによる誘起流れの強さを変更することで、噴流の拡散の程度を自由に変えることができるとされている。 For example, Patent Document 1 discloses a jet control device using a coaxial DBD plasma actuator on the jet outlet side of a nozzle. According to Patent Document 1, an induced flow is formed in the flow direction of the main jet by the DBD plasma actuator, and the strength of the induced flow by the DBD plasma is changed by controlling the magnitude and frequency of the voltage applied to the jet control device. , It is said that the degree of diffusion of the jet can be changed freely.
特許第６２１０６１５号明細書Patent No. 6210615
　しかし、特許文献１の技術をガスタービンに適用し、DBDプラズマの生成で噴流の拡散の程度を調整できたとしても、それのみでは燃焼振動の抑制を効果的に行うことはできない。 However, even if the technology of Patent Document 1 can be applied to a gas turbine and the degree of jet diffusion can be adjusted by generating DBD plasma, it is not possible to effectively suppress combustion vibration by itself.
　本発明は，特にガスタービン燃焼で生じる燃焼振動が燃焼器流入口のせん断層で生じる大規模渦が火炎を巻き込む際に急激な発熱量の変化が生じることに着目し，大規模渦の生成を制御することで燃焼振動を抑制するガスタービンの燃焼器及び燃焼制御方法を提供することを目的とする。 The present invention pays particular attention to the fact that the combustion vibration generated by gas turbine combustion causes a sudden change in calorific value when a large-scale vortex generated in the shear layer at the inlet of the combustor entrains a flame, and generates a large-scale vortex. It is an object of the present invention to provide a combustor of a gas turbine and a combustion control method for suppressing combustion vibration by controlling the combustion.
　本発明のガスタービンの燃焼器は、内部が燃焼室である筒状のダクト部と、混合ガスを前記燃焼室の入口から前記燃焼室内に供給する供給装置とを備えたガスタービンの燃焼器において、
　前記ダクト部内の圧力を検出して、圧力信号を出力する圧力センサと、
　前記燃焼室の入口に配置された、一対の電極を備えたDBDプラズマアクチュエータと、
　前記圧力センサからの圧力信号に基づいて、所定のデューティ比を持つ駆動信号を前記電極に入力することで、前記DBDプラズマアクチュエータを間欠駆動させる駆動回路と、
を有し、
　前記圧力波形の平均をゼロ点としたとき前記圧力波形の変動が負から正になるときに通過する前記ゼロ点を位相の基準点として、前記基準点に対する駆動位相θｄが存在し、前記圧力信号に対応する圧力波形の１周期を２πとし、ｎを０以上の整数としたときに、前記DBDプラズマアクチュエータは、前記圧力信号の入力から（２ｎπ＋θｄ）経過後に間欠駆動し、
　前記所定の駆動位相θｄは、０以上でπ以下、もしくは7π/4以上で２π以下である、ことを特徴とする。 The combustor of the gas turbine of the present invention is a combustor of a gas turbine including a tubular duct portion having a combustion chamber inside and a supply device for supplying mixed gas from the inlet of the combustion chamber to the combustion chamber. ,
A pressure sensor that detects the pressure inside the duct and outputs a pressure signal,
A DBD plasma actuator with a pair of electrodes located at the inlet of the combustion chamber,
A drive circuit that intermittently drives the DBD plasma actuator by inputting a drive signal having a predetermined duty ratio to the electrode based on the pressure signal from the pressure sensor.
Have,
When the average of the pressure waveform is set to the zero point, the driving phase θd with respect to the reference point exists with the zero point passing when the fluctuation of the pressure waveform changes from negative to positive as the reference point of the phase, and the pressure signal. When one cycle of the pressure waveform corresponding to is 2π and n is an integer of 0 or more, the DBD plasma actuator is intermittently driven after (2nπ + θd) has elapsed from the input of the pressure signal.
The predetermined drive phase θd is 0 or more and π or less, or 7π / 4 or more and 2π or less.
　また本発明のガスタービンの燃焼器の制御方法は、内部が燃焼室である筒状のダクト部と、混合ガスを前記燃焼室の入口から前記燃焼室内に供給する供給装置と、前記燃焼室の入口に配置された、一対の電極を備えたDBDプラズマアクチュエータと、を備えたガスタービンの燃焼器の燃焼制御方法であって、
　前記ダクト部内の圧力を検出して、圧力信号を出力し、
　前記圧力信号に基づいて、所定のデューティ比を持つ駆動信号を前記電極に入力し、
　前記圧力波形の平均をゼロ点としたとき前記圧力波形の変動が負から正になるときに通過する前記ゼロ点を位相の基準点として、前記基準点に対する駆動位相θｄが存在し、前記圧力信号に対応する圧力波形の１周期を２πとし、ｎを０以上の整数としたときに、前記圧力信号の入力から（２ｎπ＋θｄ）経過後に前記DBDプラズマアクチュエータを間欠駆動させ、
　前記所定の駆動位相θｄは、０以上でπ以下、もしくは7π/4以上で２π以下である、ことを特徴とする。 Further, the method of controlling the combustor of the gas turbine of the present invention includes a tubular duct portion whose inside is a combustion chamber, a supply device for supplying mixed gas from the inlet of the combustion chamber to the combustion chamber, and the combustion chamber. A combustion control method for a gas turbine combustor equipped with a DBD plasma actuator with a pair of electrodes located at the inlet.
The pressure in the duct portion is detected, a pressure signal is output, and the pressure signal is output.
Based on the pressure signal, a drive signal having a predetermined duty ratio is input to the electrode.
When the average of the pressure waveform is set to the zero point, the driving phase θd with respect to the reference point exists with the zero point passing when the fluctuation of the pressure waveform changes from negative to positive as the reference point of the phase, and the pressure signal. When one cycle of the pressure waveform corresponding to is 2π and n is an integer of 0 or more, the DBD plasma actuator is intermittently driven after (2nπ + θd) has elapsed from the input of the pressure signal.
The predetermined drive phase θd is 0 or more and π or less, or 7π / 4 or more and 2π or less.
　本発明によれば、大規模渦の生成を制御することで燃焼振動を抑制するガスタービンの燃焼器及びその燃焼制御方法を提供することができる。 According to the present invention, it is possible to provide a combustor of a gas turbine that suppresses combustion vibration by controlling the generation of a large-scale vortex and a combustion control method thereof.
図１は、本発明の実施形態にかかる燃焼器を含むガスタービンの概略図である。FIG. 1 is a schematic view of a gas turbine including a combustor according to an embodiment of the present invention. 図２は、本実施形態にかかる燃焼器の断面図である。FIG. 2 is a cross-sectional view of the combustor according to the present embodiment. 図３は、供給装置１４０の概略構造を示す分解図である。FIG. 3 is an exploded view showing a schematic structure of the supply device 140. 図４（ａ）は、DBDプラズマアクチュエータの軸線方向断面図であり、図４（ｂ）は、DBDプラズマアクチュエータの上面図である。FIG. 4A is an axial sectional view of the DBD plasma actuator, and FIG. 4B is a top view of the DBD plasma actuator. 図５は、駆動中のDBDプラズマアクチュエータＡＣＴの斜視図である。FIG. 5 is a perspective view of the DBD plasma actuator ACT being driven. 図６は、DBDプラズマアクチュエータを駆動する駆動回路の概略図である。FIG. 6 is a schematic diagram of a drive circuit that drives the DBD plasma actuator. 図７は、本実施形態のDBDプラズマアクチュエータの能動制御法を実行可能な駆動回路のブロック図である。FIG. 7 is a block diagram of a drive circuit capable of executing the active control method of the DBD plasma actuator of the present embodiment. 図８（ａ）は、コントローラボードＣＢのFIRフィルタに入力される、圧力センサ１４６の圧力信号の波形の一例を示す図であり、図８（ｂ）は、FIRフィルタに入力して処理された後の波形を示す図である。FIG. 8A is a diagram showing an example of the waveform of the pressure signal of the pressure sensor 146 input to the FIR filter of the controller board CB, and FIG. 8B is a diagram input to the FIR filter and processed. It is a figure which shows the latter waveform. 図９は、コントローラボードＣＢに入力される一例としての圧力波形ｐ’と、コントローラボードＣＢからのトリガ信号に応じてファンクションジェネレータＦＧから出力される駆動信号の波形Ｖｉｎとを並べて示す図である。Figure 9 is a diagram showing side by side with the pressure waveform p 'as an example to be input to the controller board CB, and a waveform V in the drive signal output from the function generator FG in response to a trigger signal from the controller board CB .. 図１０は、ダクト部の燃焼室の入口付近を示す断面図である。FIG. 10 is a cross-sectional view showing the vicinity of the inlet of the combustion chamber of the duct portion. 図１１は、図１１（ａ）～（ｈ）は，燃焼室へのガスの流入がない状態においてDBDプラズマアクチュエータを50Hz～120Hzで間欠駆動した場合に誘起される気体流れの半径方向速度の平均分布を示す図である。11 (a) to 11 (h) show the average radial velocity of the gas flow induced when the DBD plasma actuator is intermittently driven at 50 Hz to 120 Hz in the state where there is no gas inflow into the combustion chamber. It is a figure which shows the distribution. 図１２は、ダクト部の燃焼室の入口付近を示す断面図である。FIG. 12 is a cross-sectional view showing the vicinity of the inlet of the combustion chamber of the duct portion. 図１３は、OH自発光強度平均値の分布を示す図であり、（ａ）はDBDプラズマアクチュエータ不使用の条件、（ｂ）はθｄ=π／２の条件、（ｃ）はθｄ=πの条件、（ｄ）はθｄ=３π／２の条件、（ｅ）はθｄ=２πの条件による。FIG. 13 is a diagram showing the distribution of the average value of OH self-luminous intensity, in which (a) is a condition in which a DBD plasma actuator is not used, (b) is a condition of θd = π / 2, and (c) is a condition of θd = π. The condition, (d) is based on the condition of θd = 3π / 2, and (e) is based on the condition of θd = 2π. 図１４は、OH自発光強度変動の二乗平均値(RMS)の分布を示す図であり、（ａ）はDBDプラズマアクチュエータ不使用の条件、（ｂ）はθｄ=π／２の条件、（ｃ）はθｄ=πの条件、（ｄ）はθｄ=３π／２の条件、（ｅ）はθｄ=２πの条件による。FIG. 14 is a diagram showing the distribution of the root mean square (RMS) of the OH self-luminous intensity fluctuation, in which (a) is a condition in which a DBD plasma actuator is not used, (b) is a condition of θd = π / 2, and (c). ) Is based on the condition of θd = π, (d) is based on the condition of θd = 3π / 2, and (e) is based on the condition of θd = 2π. 図１５は、DBDプラズマアクチュエータの駆動位相を、θd = π/2，π，3π/2，2π の4条件にて変更した場合、および駆動しない条件での圧力変動パワースペクトルを比較して示す図である。FIG. 15 is a diagram showing a comparison of pressure fluctuation power spectra when the drive phase of the DBD plasma actuator is changed under the four conditions of θd = π / 2, π, 3π / 2, and 2π, and when the drive phase is not driven. Is. 図１６は、DBDプラズマアクチュエータの駆動位相をθd = π/2，π，3π/2，2π の4条件にて変更した場合での圧力変動RMS値p’rms 及びOH自発光強度変動RMSの空間平均値Irmsを示す図である。FIG. 16 shows the space of the pressure fluctuation RMS value p'rms and the OH self-luminous intensity fluctuation RMS when the drive phase of the DBD plasma actuator is changed under the four conditions of θd = π / 2, π, 3π / 2, 2π. It is a figure which shows the mean value Irms. 図１７は、DBDプラズマアクチュエータにおける間欠駆動のDuty比を、（a）３０％、（ｂ）５０％、（ｃ）７０％と変更した場合における、圧力変動RMS値p’rmsと、DBDプラズマアクチュエータの駆動位相との関係を示す図である。FIG. 17 shows the pressure fluctuation RMS value p'rms and the DBD plasma actuator when the duty ratio of the intermittent drive in the DBD plasma actuator is changed to (a) 30%, (b) 50%, and (c) 70%. It is a figure which shows the relationship with the drive phase of.
　以下、本発明の実施形態を具体的に説明する。
（ガスタービンの構造）
　図１は、本発明の実施形態にかかる燃焼器を含むガスタービンの概略図である。ガスタービン１０において、圧縮機１１は、空気１２を吸引して圧縮空気を生成する。圧縮空気は燃料（ここではメタンガス）と十分混合されて混合気１３を形成し、かかる混合気１３は燃焼器１４で燃焼され、高温高圧の燃焼ガス１６が生成される。燃焼ガス１６はタービン１７に供給され、ロータ１８の回転に利用される。ロータ１８の回転は圧縮機１１に伝達され、圧縮ガス１３の生成に利用される。また、ロータ１８の回転は例えば発電機１９に伝達されて発電に利用される。 Hereinafter, embodiments of the present invention will be specifically described.
(Structure of gas turbine)
FIG. 1 is a schematic view of a gas turbine including a combustor according to an embodiment of the present invention. In the gas turbine 10, the compressor 11 sucks air 12 to generate compressed air. The compressed air is sufficiently mixed with the fuel (here, methane gas) to form an air-fuel mixture 13, and the air-fuel mixture 13 is burned in the combustor 14 to generate a high-temperature and high-pressure combustion gas 16. The combustion gas 16 is supplied to the turbine 17 and used for the rotation of the rotor 18. The rotation of the rotor 18 is transmitted to the compressor 11 and used to generate the compressed gas 13. Further, the rotation of the rotor 18 is transmitted to, for example, the generator 19 and used for power generation.
（燃焼器の構造）
　図２は、燃焼器１４の断面図である。以降の図において、燃焼器の軸線は上下方向に延在し、図で下方が圧縮機側であり、上方がタービン側とする。燃焼器１４は、圧縮機側の供給装置１４０と、タービン側のダクト部１４５とを連結してなる。 (Combustor structure)
FIG. 2 is a cross-sectional view of the combustor 14. In the following figures, the axis of the combustor extends in the vertical direction, with the lower part being the compressor side and the upper part being the turbine side. The combustor 14 is formed by connecting a supply device 140 on the compressor side and a duct portion 145 on the turbine side.
　ダクト部１４５は、全長が１１７５mmであるが、それに限られない。ダクト部１４５において、供給装置側端部より４５０mmの位置に、圧力センサ１４６を取り付けている。ダクト部１４５の内部が燃焼室となる。 The total length of the duct portion 145 is 1175 mm, but the total length is not limited to that. In the duct portion 145, the pressure sensor 146 is attached at a position 450 mm from the end portion on the side of the supply device. The inside of the duct portion 145 becomes a combustion chamber.
　図３は、供給装置１４０の概略構造を示す分解図である。供給装置１４０は、ダクト部１４５に接続されるノズル部１４１ａと、燃焼室の入口から上流に向かって１００mmの位置においてノズル部１４１ａに組み込まれたスワーラ１４１ｂとを有する。ノズル部１４１ａは、中空円筒状の外壁部１４１ｃと、中央の円柱状の整流部１４１ｄと、外壁部１４１ｃから放射方向に延在するフランジ部１４１ｅとを有する。外壁部１４１ｃと整流部１４１ｄとの間が、圧縮ガスの流路ＦＰとなる。ダクト部１４５とノズル部１４１ａとの連結部における流路ＦＰの出口が、燃焼室入口となる。 FIG. 3 is an exploded view showing a schematic structure of the supply device 140. The supply device 140 has a nozzle portion 141a connected to the duct portion 145 and a swirler 141b incorporated in the nozzle portion 141a at a position 100 mm upstream from the inlet of the combustion chamber. The nozzle portion 141a has a hollow cylindrical outer wall portion 141c, a central cylindrical rectifying portion 141d, and a flange portion 141e extending in the radial direction from the outer wall portion 141c. The space between the outer wall portion 141c and the rectifying portion 141d serves as the flow path FP for the compressed gas. The outlet of the flow path FP at the connecting portion between the duct portion 145 and the nozzle portion 141a serves as the combustion chamber inlet.
　整流部１４１ｄのダクト部側の端部は、ダクト部に向かって大径となる円錐台形状となっており、これにより圧縮ガスの流路ＦＰは出口で絞られることとなる。この出口において、整流部１４１ｄの外径は１５ｍｍであり、外壁部１４１ｃの内径は３０mmであるが、これに限られない。 The end of the rectifying section 141d on the duct section side has a truncated cone shape with a larger diameter toward the duct section, whereby the flow path FP of the compressed gas is throttled at the outlet. At this outlet, the outer diameter of the rectifying portion 141d is 15 mm, and the inner diameter of the outer wall portion 141c is 30 mm, but the present invention is not limited to this.
　二重円筒状のスワーラ１４１ｂは、所定のスワール角でらせん状に湾曲した複数の羽根１４１ｆを備えており、流路ＦＰを通過する圧縮ガスに旋回流を付与する機能を有する。流路ＦＰの出口から燃焼室内に噴き出された圧縮ガスは、不図示の点火栓により着火されて燃焼し、燃焼ガスがダクト部１４５の端部から排出される。 The double-cylindrical swirler 141b is provided with a plurality of blades 141f that are spirally curved at a predetermined swirl angle, and has a function of imparting a swirling flow to the compressed gas passing through the flow path FP. The compressed gas ejected from the outlet of the flow path FP into the combustion chamber is ignited by an ignition plug (not shown) and burned, and the combustion gas is discharged from the end of the duct portion 145.
　フランジ部１４１ｅの上面には、圧縮ガスの流路ＦＰの出口を囲うようにして、DBDプラズマアクチュエータＡＣＴが組み付けられている。 A DBD plasma actuator ACT is assembled on the upper surface of the flange portion 141e so as to surround the outlet of the compressed gas flow path FP.
　図４（ａ）は、DBDプラズマアクチュエータの軸線方向断面図であり、図４（ｂ）は、DBDプラズマアクチュエータの上面図である。燃焼室の入口に設けられたDBDプラズマアクチュエータＡＣＴは、環状板の誘電体ＬＬ（ここでは５００μｍ厚のアルミナ板）の上面に、環状の上部電極ＥＬ１（ここでは７０μｍの銅板）を同軸に配置し、また誘電体ＬＬの下面に、環状の下部電極ＥＬ２（ここでは７０μｍの銅板）を同軸に配置してなる。上部電極ＥＬ１の内径が下部電極ＥＬ２の外径に一致するよう、シフト配置がなされている。上部電極ＥＬ１及び下部電極ＥＬ２は、後述する駆動回路に接続されている。 FIG. 4A is an axial sectional view of the DBD plasma actuator, and FIG. 4B is a top view of the DBD plasma actuator. In the DBD plasma actuator ACT provided at the inlet of the combustion chamber, the annular upper electrode EL1 (here, a 70 μm copper plate) is coaxially arranged on the upper surface of the dielectric LL (here, a 500 μm thick alumina plate) of the annular plate. Further, an annular lower electrode EL2 (here, a 70 μm copper plate) is coaxially arranged on the lower surface of the dielectric LL. The shift arrangement is made so that the inner diameter of the upper electrode EL1 matches the outer diameter of the lower electrode EL2. The upper electrode EL1 and the lower electrode EL2 are connected to a drive circuit described later.
　誘電体ＬＬの外径は６０mmであり、上部電極ＥＬ１の外径は５０mmであり、上部電極ＥＬ１の内径及び下部電極ＥＬ２の外径は４０mmであり、下部電極ＥＬ２の内径及び誘電体ＬＬの内径は３０mmであるが、これに限られることはない。なお、DBDプラズマアクチュエータにおいて、二対以上の電極を含むものであっても後述するような流動を引き起こす効果を有するものであれば使用可能である。例えば，二対の半円形状の電極を組み合わせて一対の円形状の電極としても、同様の効果が得られる。 The outer diameter of the dielectric LL is 60 mm, the outer diameter of the upper electrode EL1 is 50 mm, the inner diameter of the upper electrode EL1 and the outer diameter of the lower electrode EL2 are 40 mm, the inner diameter of the lower electrode EL2 and the inner diameter of the dielectric LL. Is 30 mm, but is not limited to this. It should be noted that even if the DBD plasma actuator includes two or more pairs of electrodes, it can be used as long as it has the effect of inducing flow as described later. For example, the same effect can be obtained by combining two pairs of semicircular electrodes to form a pair of circular electrodes.
　図５は、駆動中のDBDプラズマアクチュエータＡＣＴの斜視図である。図５中、符号ＰＭで示す環状の範囲はプラズマの発生による発光（青紫色光）を示しており，DBDプラズマアクチュエータＡＣＴを作動させることで燃焼器中心軸に向かう半径方向の流れが誘起されることがわかる。 FIG. 5 is a perspective view of the DBD plasma actuator ACT being driven. In FIG. 5, the annular range indicated by the symbol PM indicates light emission (blue-purple light) due to the generation of plasma, and the radial flow toward the central axis of the combustor is induced by operating the DBD plasma actuator ACT. You can see that.
（DBDプラズマアクチュエータの駆動回路）
　図６は、DBDプラズマアクチュエータを駆動する駆動回路ＤＲ１の概略図である。ファンクションジェネレータＦＧで生成した高周波正弦波を、パワーアンプＡＭＰ、変圧器ＴＲを介して電圧増幅し、生成した高周波数高電圧の信号をDBDプラズマアクチュエータＡＣＴの電極ＥＬ１，ＥＬ２に入力することで向心流動を発生させることができる。駆動回路ＤＲ１は、供給装置１４０とは離間して設置される。 (Drive circuit of DBD plasma actuator)
FIG. 6 is a schematic view of the drive circuit DR1 that drives the DBD plasma actuator. The high-frequency sine wave generated by the function generator FG is voltage-amplified via the power amplifier AMP and the transformer TR, and the generated high-frequency high-voltage signal is input to the electrodes EL1 and EL2 of the DBD plasma actuator ACT to be centripetal. Flow can be generated. The drive circuit DR1 is installed separately from the supply device 140.
　図７は、本実施形態のDBDプラズマアクチュエータの能動制御法を実行可能な駆動回路ＤＲ２のブロック図である。図６の駆動回路ＤＲ１に対し、ファンクションジェネレータＦＧにトリガ信号を入力する手段を設けた点が主として異なる。 FIG. 7 is a block diagram of the drive circuit DR2 capable of executing the active control method of the DBD plasma actuator of the present embodiment. The main difference is that the drive circuit DR1 of FIG. 6 is provided with a means for inputting a trigger signal to the function generator FG.
　図７の駆動回路ＤＲ２において、ダクト部１４５に備えた圧力センサ１４６（Ｋｉｓｔｌｅｒ社製、商品名７０６１Ｃ）が燃焼室の圧力変動を検知し、それに応じた圧力信号を出力する。その圧力信号をパワーアンプＡＭＰ（Ｋｉｓｔｌｅｒ社製、商品名Ｔｙｐｅ５０１８）で増幅した後、アンチエイリアシングフィルタＡＡＦ（ＮＦ回路ブロック社製、商品名ＤＴ　Ｆｉｌｔｅｒ３３４４）で高周波数をカットし、更にコントローラボードＣＢ（ｄＳＰＡＣＥ社製、商品名ＤＳ１１０４）でサンプリング処理を行う。具体的には、コントローラボードＣＢ内にて，有限インパルス応答(FIR)フィルタにより200Hz以上（但し燃焼振動の周波数に依存して決定される）の高周波成分を除去し，過去1秒分のデータの平均と差分を取ることで圧力変動を算出する。この圧力変動にかかる波形データを含むトリガ信号は、コントローラボードＣＢからファンクションジェネレータＦＧ（Ｓｏｎｙ　Ｔｅｋｔｒｏｎｉｘ社製、商品名ＡＦＧ３２０）に入力される。 In the drive circuit DR2 of FIG. 7, the pressure sensor 146 (manufactured by Kistler, trade name 7061C) provided in the duct portion 145 detects the pressure fluctuation in the combustion chamber and outputs a pressure signal corresponding to the pressure fluctuation. After amplifying the pressure signal with a power amplifier AMP (manufactured by Kistler, trade name Type5018), a high frequency is cut by an antialiasing filter AAF (manufactured by NF circuit block, trade name DT Filter3344), and further, a controller board CB (dSPACE). The sampling process is performed with the product name DS1104) manufactured by the company. Specifically, in the controller board CB, a finite impulse response (FIR) filter removes high-frequency components of 200 Hz or higher (however, it is determined depending on the frequency of combustion vibration), and the data for the past 1 second is collected. The pressure fluctuation is calculated by taking the difference from the average. The trigger signal including the waveform data related to the pressure fluctuation is input from the controller board CB to the function generator FG (manufactured by Sony Tektronix, trade name AFG320).
　図８（ａ）は、コントローラボードＣＢ内のFIRフィルタに入力される、圧力センサ１４６の圧力信号の波形の一例を示しており、高周波ノイズが重畳されていることがわかる。これを、FIRフィルタに入力して処理することで、図８（ｂ）に示すような、滑らかな周期波形のデータが得られる。 FIG. 8A shows an example of the waveform of the pressure signal of the pressure sensor 146 input to the FIR filter in the controller board CB, and it can be seen that high frequency noise is superimposed. By inputting this into the FIR filter and processing it, data of a smooth periodic waveform as shown in FIG. 8B can be obtained.
　波形データが入力されたコントローラボードＣＢは、ファンクションジェネレータＦＧにトリガ信号を送信し、ファンクションジェネレータＦＧからDBDプラズマアクチュエータＡＣＴに駆動信号を送信する。入力電圧、入力周波数、駆動位相、間欠駆動Duty比は、事前にファンクションジェネレータＦＧに入力されており、駆動位相はコントローラボードＣＢに事前に入力された値を使用する。ここでは圧力変動が負から正に変わる点を位相の基準点とし、圧力変動とDBDプラズマアクチュエータＡＣＴの駆動開始の差を、圧力変動位相に基づく駆動位相（θd）と定義する。 The controller board CB into which the waveform data is input transmits a trigger signal to the function generator FG, and transmits a drive signal from the function generator FG to the DBD plasma actuator ACT. The input voltage, input frequency, drive phase, and intermittent drive duty ratio are input to the function generator FG in advance, and the drive phase uses the values input to the controller board CB in advance. Here, the point at which the pressure fluctuation changes from negative to positive is defined as the phase reference point, and the difference between the pressure fluctuation and the drive start of the DBD plasma actuator ACT is defined as the drive phase (θd) based on the pressure fluctuation phase.
　図９は、コントローラボードＣＢに入力される一例としての圧力波形ｐ’と、コントローラボードＣＢからのトリガ信号に応じてファンクションジェネレータＦＧから出力される駆動信号の波形Ｖｉｎとを並べて示す図である。駆動信号の周波数は、任意に変更可能である。 Figure 9 is a diagram showing side by side with the pressure waveform p 'as an example to be input to the controller board CB, and a waveform V in the drive signal output from the function generator FG in response to a trigger signal from the controller board CB .. The frequency of the drive signal can be changed arbitrarily.
（実験）
　以下、本発明者らが行った実験について説明する。この実験は，メタン・空気予混合気の旋回乱流火炎を形成するために、図１～３に示すスワール型の燃焼器１４を用いて行い、またDBDプラズマアクチュエータの制御には図７の駆動回路ＤＲ２を用いた。予混合気は燃焼器下部の四方から流入し，スワール角45度のスワーラ１４１ｂを通過した後，内径30mm，長さ100mmの外壁部１４１ｃ内を通って燃焼室へと導かれるようにした。 (Experiment)
Hereinafter, the experiments conducted by the present inventors will be described. This experiment was performed using the swirl-type combustor 14 shown in FIGS. 1 to 3 in order to form a swirling turbulent flame of the methane-air premixture, and the drive of FIG. 7 was used to control the DBD plasma actuator. Circuit DR2 was used. The premixture flows in from all four sides of the lower part of the combustor, passes through the swirl 141b with a swirl angle of 45 degrees, and then is guided to the combustion chamber through the outer wall portion 141c having an inner diameter of 30 mm and a length of 100 mm.
　外壁部１４１ｃの中心軸上には外径10mmの整流部１４１ｄが取り付けられ，燃焼室入口に向かって外径15mmに広がるようにした。燃焼室は断面120mm×120mmの角柱状となっており，長さは1175mmとなっている。図１０に示すように、ダクト部１４５の燃焼室の入口付近は四方を石英ガラスＧＬで囲まれており，外部から燃焼室内の光学計測が可能となっている。 A rectifying unit 141d with an outer diameter of 10 mm was mounted on the central axis of the outer wall portion 141c so that the outer diameter expanded to 15 mm toward the inlet of the combustion chamber. The combustion chamber is a prism with a cross section of 120 mm x 120 mm and a length of 1175 mm. As shown in FIG. 10, the vicinity of the entrance of the combustion chamber of the duct portion 145 is surrounded on all sides by quartz glass GL, and optical measurement in the combustion chamber is possible from the outside.
　本発明者らは、DBDプラズマアクチュエータを、条件を変えて駆動することにより比較試験を行った。ここでは、DBDプラズマアクチュエータの駆動は，図７に示すように、ファンクションジェネレータＦＧにより生成された入力周波数10kHz，入力電圧1Vppの正弦波信号を、パワーアンプＡＭＰ(Classic Pro社製、商品名CP500X)及び変圧器により電圧を約8000倍に増幅し，DBDプラズマアクチュエータの電極に入力することで行った。正弦波の変化に対応してプラズマが発生するが，駆動信号を入力している期間はDBDプラズマアクチュエータが動作しているものとし，入力信号のオン/オフの繰り返しにより間欠的な駆動を実現した。 The present inventors conducted a comparative test by driving the DBD plasma actuator under different conditions. Here, as shown in FIG. 7, the DBD plasma actuator is driven by using a sine wave signal with an input frequency of 10 kHz and an input voltage of 1 Vpp generated by the function generator FG as a power amplifier AMP (manufactured by Classic Pro, trade name CP500X). The voltage was amplified about 8000 times by a transformer and input to the electrodes of the DBD plasma actuator. Plasma is generated in response to changes in the sine wave, but it is assumed that the DBD plasma actuator is operating during the period when the drive signal is being input, and intermittent drive is realized by repeating on / off of the input signal. ..
　図１１（ａ）～（ｈ）は，燃焼室へのガスの流入がない状態においてDBDプラズマアクチュエータを50Hz～120Hzで間欠駆動した場合に誘起される気体流れの半径方向速度の平均分布を示している。ここで間欠駆動のオン/オフのDuty（デューティ）比は50%とした。気体の速度はステレオ粒子画像流速計により計測し，速度算出の際の検査領域の大きさは480μm×480μmとし，レーザシート厚さは800μmとした。 11 (a) to 11 (h) show the average distribution of the radial velocity of the gas flow induced when the DBD plasma actuator is intermittently driven at 50 Hz to 120 Hz in the state where there is no gas inflow into the combustion chamber. There is. Here, the duty ratio of the intermittent drive on / off is set to 50%. The velocity of the gas was measured by a stereo particle image velocimetry, and the size of the inspection area when calculating the velocity was 480 μm × 480 μm, and the thickness of the laser sheet was 800 μm.
　計測した領域は、図１２のハッチングで示すように，燃焼器（整流部１４１ｄ）の中心軸を計測領域の一辺とする24mm×24mmであり，各分布の右端はDBDプラズマアクチュエータの上部電極の端に相当する。間欠駆動の周波数によって誘起される半径速度分布はわずかに異なり，周波数が高くなるとDBDプラズマアクチュエータ上においても燃焼器中心軸に向かう気体の速度増加が観察された。しかし，燃焼室流入口外周付近から燃焼器中心軸に向かう気体の半径方向平均速度は、間欠駆動の周波数に依らず概ね1m/s程度であることがわかった。また，間欠的な駆動では，その周波数において顕著な流速の変動が観察された。 As shown by the hatching in FIG. 12, the measured area is 24 mm × 24 mm with the central axis of the combustor (rectifying unit 141d) as one side of the measurement area, and the right end of each distribution is the end of the upper electrode of the DBD plasma actuator. Corresponds to. The radial velocity distribution induced by the intermittent drive frequency was slightly different, and an increase in the velocity of the gas toward the central axis of the combustor was observed on the DBD plasma actuator as the frequency increased. However, it was found that the average radial velocity of the gas from the vicinity of the outer circumference of the combustion chamber inlet to the central axis of the combustor is about 1 m / s regardless of the frequency of intermittent drive. In the intermittent driving, remarkable fluctuations in the flow velocity were observed at that frequency.
　次に、本発明者らは、焼室内の圧力を検出する圧力センサの信号を入力とした能動制御を行い，DBDプラズマアクチュエータを圧力変動に関連させ間欠駆動を行うことによる効果を確認した。 Next, the present inventors confirmed the effect of performing active control using the signal of the pressure sensor that detects the pressure in the firing chamber as an input, and performing intermittent drive in relation to the pressure fluctuation of the DBD plasma actuator.
　DBDプラズマアクチュエータの駆動タイミングの制御は、図７に示す駆動回路ＤＲ２にて行った。DBDプラズマアクチュエータの間欠駆動は，圧力変動の基準となる点から一定時間後に駆動を開始することとした。ここで圧力波形の平均をゼロ点としたとき圧力変動（圧力波形）が負から正になるときに通過するゼロ点を位相の基準点とし，前記基準点に対して、DBDプラズマアクチュエータが駆動を開始するまでの差異（ずれ）を、圧力変動の位相に基づく駆動位相θdとする。 The drive timing of the DBD plasma actuator was controlled by the drive circuit DR2 shown in FIG. The intermittent drive of the DBD plasma actuator will start after a certain period of time from the point that serves as the reference for pressure fluctuations. Here, when the average of the pressure waveforms is set to the zero point, the zero point that passes when the pressure fluctuation (pressure waveform) changes from negative to positive is set as the phase reference point, and the DBD plasma actuator drives the reference point. The difference (deviation) until the start is defined as the drive phase θd based on the phase of the pressure fluctuation.
　ファンクションジェネレータＦＧへのトリガ信号入力からDBDプラズマアクチュエータの駆動までの遅れが事前に計測されており，かかる遅れを考慮して駆動位相θdが決定される。FIRフィルタを施すことにより，圧力変動信号の位相の遅れが発生するため，基準点から（2ｎπ+θd）だけ位相をずらして駆動信号を送信し、DBDプラズマアクチュエータの駆動を行った（図９）。ただし，ｎを０以上の整数とする。ファンクションジェネレータＦＧにトリガ信号を送る時間を変更することにより，任意の位相で駆動を開始することが可能である。また，1回の駆動信号の送信でDBDプラズマアクチュエータを駆動する時間は変更可能であり，任意の周波数及びDuty比で間欠駆動が可能である。 The delay from the trigger signal input to the function generator FG to the drive of the DBD plasma actuator is measured in advance, and the drive phase θd is determined in consideration of this delay. Since the phase of the pressure fluctuation signal is delayed by applying the FIR filter, the drive signal is transmitted with the phase shifted by (2nπ + θd) from the reference point to drive the DBD plasma actuator (Fig. 9). .. However, n is an integer of 0 or more. By changing the time for sending the trigger signal to the function generator FG, it is possible to start driving in any phase. In addition, the time to drive the DBD plasma actuator can be changed by transmitting one drive signal, and intermittent drive is possible at any frequency and duty ratio.
　本発明者らは、OH自発光と圧力変動から火炎の変動特性を評価した。OH自発光は中心波長320nm，半値幅43.8nmのバンドパスフィルタ(Semrock社製,商品名FF01-320/40-50-D)が装着された紫外域対応のレンズ(Nikon社製,商品名UV-105mmF4.5)により集光され，イメージ・インテンシファイア(浜松ホトニクス社製,商品名C10880-03F)により増幅され，高速度CMOSカメラ(Photron社製,商品名SA-X2)により撮影された。カメラとイメージ・インテンシファイアの同期はディレイパルス・パルスジェネレータ(Berkeley Nucleonics社製,商品名MODEL 575 PULSE DELAY GENERATOR)を用いた。燃焼器内の圧力変動計測には，制御に用いた圧力センサ・アンプからのデータをA/Dボード(National Instruments社製,商品名PCI-6115)で取得することにより行った。 The present inventors evaluated the fluctuation characteristics of the flame from OH self-luminous emission and pressure fluctuation. OH self-luminous is an ultraviolet compatible lens (Nikon, trade name UV) equipped with a bandpass filter (Semrock, trade name FF01-320 / 40-50-D) with a center wavelength of 320 nm and a half-price width of 43.8 nm. -105mmF4.5) focused, amplified by an image intensifier (Hamamatsu Photonics, trade name C10880-03F), and photographed by a high-speed CMOS camera (Photron, trade name SA-X2). .. A delay pulse pulse generator (manufactured by Berkeley Nucleonics, trade name MODEL 575 PULSE DELAY GENERATOR) was used to synchronize the camera and image intensifier. The pressure fluctuation measurement in the combustor was performed by acquiring the data from the pressure sensor / amplifier used for control with an A / D board (manufactured by National Instruments, trade name PCI-6115).
　ここでは、スワール型の燃焼器において弱い振動燃焼が生じる当量比0.65，流量250L/min の条件とした。DBDプラズマアクチュエータへの入力信号は，入力周波数10kHz，入力電圧8.6kVpp の正弦波とした。駆動位相をθd = π/2，π，3π/2，2π の4条件で制御を行い、その間欠駆動のDuty比は50%とし、更にDBDプラズマアクチュエータを駆動しない場合と比較した。 Here, the conditions were set to an equivalent ratio of 0.65 and a flow rate of 250 L / min, where weak vibration combustion occurs in a swirl type combustor. The input signal to the DBD plasma actuator was a sine wave with an input frequency of 10 kHz and an input voltage of 8.6 kVpp. The drive phase was controlled under four conditions of θd = π / 2, π, 3π / 2, 2π, and the duty ratio of the intermittent drive was set to 50%, and the comparison was made with the case where the DBD plasma actuator was not driven.
　図１０の枠ＦＲで示す領域が、OH自発光の撮影領域である。具体的には、ＯＨ自発光計測を枠ＦＲで囲まれた燃焼室入口直上の117mm×117mmの範囲で行った。イメージ・インテンシファイアのゲインは860，ゲート幅は80μs，撮影速度は10kHzとした。圧力変動の計測速度は20kHzとした。これらの計測時間は約2.2秒とした。 The area indicated by the frame FR in FIG. 10 is the OH self-luminous photographing area. Specifically, OH self-luminous measurement was performed in a range of 117 mm × 117 mm directly above the inlet of the combustion chamber surrounded by the frame FR. The gain of the image intensifier was 860, the gate width was 80 μs, and the shooting speed was 10 kHz. The measurement speed of pressure fluctuation was set to 20 kHz. These measurement times were set to about 2.2 seconds.
　図１３に、OH自発光強度平均値の分布を示す。OH自発光強度平均値の分布は，すべての条件で最大となるOH自発光強度平均値で正規化している。OH自発光強度平均値の分布は，各条件で大きな違いは見られないが，駆動制御をθd = π/2 で行った場合に火炎がわずかに下流側に拡がっている様子が観察できる。 FIG. 13 shows the distribution of the average value of OH self-luminous intensity. The distribution of the average OH self-luminous intensity is normalized by the average OH self-luminous intensity, which is the maximum under all conditions. The distribution of the average OH self-luminous intensity does not differ significantly under each condition, but it can be observed that the flame spreads slightly downstream when the drive control is performed with θd = π / 2.
　図１４にOH自発光強度変動の二乗平均値(RMS)の分布を示す。各分布は全ての条件で最大となるOH自発光強度変動のRMS 値で正規化されている。駆動制御をθd = π/2 で行った場合，変動領域は半径方向にわずかに狭まり，下流方向に拡がることがわかる。また，変動のRMS 値が全体的に抑制されている様子が観察される。 FIG. 14 shows the distribution of the root mean square (RMS) of the OH self-luminous intensity fluctuation. Each distribution is normalized by the RMS value of the OH self-luminous intensity fluctuation, which is the maximum under all conditions. It can be seen that when the drive control is performed with θd = π / 2, the fluctuation region narrows slightly in the radial direction and expands in the downstream direction. In addition, it is observed that the RMS value of fluctuation is suppressed as a whole.
　図１５に、DBDプラズマアクチュエータの駆動位相をθd = π/2，π，3π/2，2π の4条件にて変更した場合、および駆動しない条件（アクチュエータ不使用）での圧力変動パワースペクトルを示す。DBDプラズマアクチュエータを駆動しない場合，ピーク周波数は約67Hz であり，約75Hz近傍に第2のピークが観察される。 FIG. 15 shows the pressure fluctuation power spectrum when the drive phase of the DBD plasma actuator is changed under the four conditions of θd = π / 2, π, 3π / 2, 2π, and when the drive phase is not driven (without the actuator). .. When the DBD plasma actuator is not driven, the peak frequency is about 67Hz, and the second peak is observed near about 75Hz.
　これに対し、DBDプラズマアクチュエータの駆動制御をθd = π, 3π/2 で行った場合は、駆動なしの条件との大きな変化は見られないが，θd = 2π で駆動制御を行った場合，ピーク周波数が約66Hz に移るとともにピークのエネルギーが低下することがわかる。さらに、θd = π/2 で制御を行った場合は，ピーク周波数は約66Hz であり，ピークのエネルギーが大きく低下することがわかる。また，第2のピーク周辺のエネルギーも大きく低下することがわかる。 On the other hand, when the drive control of the DBD plasma actuator is performed with θd = π, 3π / 2, there is no significant change from the condition without drive, but when the drive control is performed with θd = 2π, it peaks. It can be seen that the peak energy decreases as the frequency shifts to about 66 Hz. Furthermore, when control is performed with θd = π / 2, the peak frequency is about 66 Hz, and it can be seen that the peak energy drops significantly. It can also be seen that the energy around the second peak also drops significantly.
　図１６に、DBDプラズマアクチュエータの駆動位相をθd = π/2，π，3π/2，2π の4条件にて変更した場合における、圧力変動RMS値p’rms 及びOH自発光強度変動RMSの空間平均値Irmsを示す。図中の水平実線及び水平点線は，DBDプラズマアクチュエータを駆動しない条件（アクチュエータ不使用）でのRMS値を示している。 FIG. 16 shows the space of the pressure fluctuation RMS value p'rms and the OH self-luminous intensity fluctuation RMS when the drive phase of the DBD plasma actuator is changed under the four conditions of θd = π / 2, π, 3π / 2, 2π. The average value Irms is shown. The horizontal solid line and horizontal dotted line in the figure show the RMS value under the condition that the DBD plasma actuator is not driven (actuator not used).
　DBDプラズマアクチュエータを駆動しない条件と比較して，駆動制御をθd = 3π/2 で行った場合は，僅かに変動が増大し，θd = πでは駆動しない条件と大きく変わらないことがわかる。また、θd = 2πでは圧力変動のみ約16%低減されている。さらに、θd = π/2 で制御した場合、p’rms は約49%，Irms は約16%と大幅に抑制される。これらの結果は，DBDプラズマアクチュエータの間欠駆動の駆動位相を適切に選択することにより，圧力変動及びOH自発光強度変動を抑制可能であることを示している。 Compared to the condition where the DBD plasma actuator is not driven, when the drive control is performed with θd = 3π / 2, the fluctuation increases slightly, and it can be seen that it is not significantly different from the condition without driving with θd = π. Also, at θd = 2π, only the pressure fluctuation is reduced by about 16%. Furthermore, when controlled with θd = π / 2, p'rms is significantly suppressed to about 49% and Irms to about 16%. These results indicate that pressure fluctuations and OH self-luminous intensity fluctuations can be suppressed by appropriately selecting the drive phase for intermittent drive of the DBD plasma actuator.
　以上の実験によれば、燃焼温度により圧力変動周波数が変わるが、DBDプラズマアクチュエータを燃焼器流入口外周に設置し、燃焼ダクトに設置された圧力センサの信号に基づいて、燃焼器内の圧力変動に対して所定範囲の位相差を与え、外側せん断層において主流と交差する流れを誘起することにより、燃焼振動を能動的に抑制することが可能となることがわかった。 According to the above experiment, the pressure fluctuation frequency changes depending on the combustion temperature, but the pressure fluctuation in the combustor is based on the signal of the pressure sensor installed in the combustion duct by installing the DBD plasma actuator on the outer circumference of the combustion inlet. It was found that the combustion vibration can be actively suppressed by giving a phase difference within a predetermined range to induce a flow that intersects the mainstream in the outer shear layer.
　図１７に、DBDプラズマアクチュエータにおける間欠駆動のDuty比を、（a）３０％、（ｂ）５０％、（ｃ）７０％と変更した場合における、圧力変動RMS値p’rmsと、DBDプラズマアクチュエータの駆動位相との関係を示す図である。なお、Duty比は30%とは、オン／オフの１周期の時間をＴとしたときに、オン時間が０．３Ｔであり、オフ時間が０．７Ｔであることを意味する。 FIG. 17 shows the pressure fluctuation RMS value p'rms and the DBD plasma actuator when the duty ratio of the intermittent drive in the DBD plasma actuator is changed to (a) 30%, (b) 50%, and (c) 70%. It is a figure which shows the relationship with the drive phase of. The duty ratio of 30% means that the on time is 0.3T and the off time is 0.7T, where T is the time of one cycle of on / off.
　ここでは、スワール型の燃焼器において弱い振動燃焼が生じる当量比0.66，流量250L/min の条件とした。DBDプラズマアクチュエータへの入力信号は，入力周波数10kHz，入力電圧8.6kVpp の正弦波とした。駆動位相をθd =π/4，π/2，3π/4，π，5π/4，3π/2，7π/4，2π の8条件で制御を行い、その間欠駆動のDuty比は30%、50%、70%とした。圧力変動の計測速度は20kHzとした。これらの計測時間は約10秒とした。 Here, the conditions were set to an equivalent ratio of 0.66 and a flow rate of 250 L / min, in which weak vibration combustion occurs in a swirl-type combustor. The input signal to the DBD plasma actuator was a sine wave with an input frequency of 10 kHz and an input voltage of 8.6 kVpp. The drive phase is controlled under 8 conditions of θd = π / 4, π / 2, 3π / 4, π, 5π / 4, 3π / 2, 7π / 4, 2π, and the duty ratio of intermittent drive is 30%. It was set to 50% and 70%. The measurement speed of pressure fluctuation was set to 20 kHz. These measurement times were set to about 10 seconds.
　図１７の実験結果によれば、Duty比を50%から増加させても、圧力変動抑制効果の向上はあまり見られないのに対し、30％に減少させると該効果が確認され、かつ適用できる駆動位相θｄの範囲も拡大することがわかる。駆動位相θｄは、０以上でπ以下、もしくは7π/4以上で２π以下とすると効果がある。 According to the experimental results of FIG. 17, even if the duty ratio is increased from 50%, the pressure fluctuation suppressing effect is not significantly improved, but when it is decreased to 30%, the effect is confirmed and applicable. It can be seen that the range of the drive phase θd is also expanded. It is effective when the drive phase θd is 0 or more and π or less, or 7π / 4 or more and 2π or less.
　本発明者らが行った実験を通じて、DBDプラズマアクチュエータを間欠駆動させ，圧力センサ信号を入力とした能動制御を行い，DBDプラズマアクチュエータの駆動位相が燃焼特性に与える影響につき検討したところ、以下の知見を得た。
（１）DBDプラズマアクチュエータを間欠的に駆動し，駆動位相を適切に選択することにより，圧力変動及びOH自発光強度変動を抑制可能である。
（２）DBDプラズマアクチュエータの有効な制御により，火炎は下流側に拡がり，変動領域は半径方向に狭まる。
（３）DBDプラズマアクチュエータの有効な制御により，圧力変動のパワースペクトルのピーク周波数が低下する。 Through the experiments conducted by the present inventors, the DBD plasma actuator was intermittently driven, active control was performed using the pressure sensor signal as an input, and the effect of the drive phase of the DBD plasma actuator on the combustion characteristics was examined. Got
(1) By intermittently driving the DBD plasma actuator and appropriately selecting the drive phase, it is possible to suppress pressure fluctuations and OH self-luminous intensity fluctuations.
(2) By effective control of the DBD plasma actuator, the flame spreads to the downstream side and the fluctuation region narrows in the radial direction.
(3) Effective control of the DBD plasma actuator reduces the peak frequency of the power spectrum of pressure fluctuations.
１０　ガスタービン
１１　圧縮機
１２　空気
１３　混合気
１４　燃焼器
１６　燃焼ガス
１７　タービン
１８　ロータ
１９　発電機
ＡＣＴ　DBDプラズマアクチュエータ
ＤＲ１，ＤＲ２　駆動回路 10 Gas turbine 11 Compressor 12 Air 13 Air-fuel mixture 14 Combustor 16 Combustor 16 Turbine 18 Rotor 19 Generator ACT DBD Plasma actuator DR1, DR2 Drive circuit

Claims (6)

  1. 　内部が燃焼室である筒状のダクト部と、混合ガスを前記燃焼室の入口から前記燃焼室内に供給する供給装置とを備えたガスタービンの燃焼器において、
    　前記ダクト部内の圧力を検出して、圧力信号を出力する圧力センサと、
    　前記燃焼室の入口に配置された、一対の電極を備えたDBDプラズマアクチュエータと、
    　前記圧力センサからの圧力信号に基づいて、所定のデューティ比を持つ駆動信号を前記電極に入力することで、前記DBDプラズマアクチュエータを間欠駆動させる駆動回路と、
    を有し、
    　前記圧力波形の平均をゼロ点としたとき前記圧力波形の変動が負から正になるときに通過する前記ゼロ点を位相の基準点として、前記基準点に対する駆動位相θｄが存在し、前記圧力信号に対応する圧力波形の１周期を２πとし、ｎを０以上の整数としたときに、前記DBDプラズマアクチュエータは、前記圧力信号の入力から（２ｎπ＋θｄ）経過後に間欠駆動し、
    　前記所定の駆動位相θｄは、０以上でπ以下、もしくは7π/4以上で２π以下である、
    ことを特徴とするガスタービンの燃焼器。     In a gas turbine combustor provided with a tubular duct portion having a combustion chamber inside and a supply device for supplying a mixed gas from the inlet of the combustion chamber to the combustion chamber.
    A pressure sensor that detects the pressure inside the duct and outputs a pressure signal,
    A DBD plasma actuator with a pair of electrodes located at the inlet of the combustion chamber,
    A drive circuit that intermittently drives the DBD plasma actuator by inputting a drive signal having a predetermined duty ratio to the electrode based on the pressure signal from the pressure sensor.
    Have,
    When the average of the pressure waveform is set to the zero point, the driving phase θd with respect to the reference point exists with the zero point passing when the fluctuation of the pressure waveform changes from negative to positive as the reference point of the phase, and the pressure signal. When one cycle of the pressure waveform corresponding to is 2π and n is an integer of 0 or more, the DBD plasma actuator is intermittently driven after (2nπ + θd) has elapsed from the input of the pressure signal.
    The predetermined drive phase θd is 0 or more and π or less, or 7π / 4 or more and 2π or less.
    A gas turbine combustor characterized by that.
  2. 　前記駆動信号のデューティ比は５０％以下である、
    ことを特徴とする請求項１に記載のガスタービンの燃焼器。     The duty ratio of the drive signal is 50% or less.
    The combustor of the gas turbine according to claim 1.
  3. 　前記供給装置は、スワーラを有する、
    ことを特徴とする請求項１または２に記載のガスタービンの燃焼器。     The feeder has a swirler.
    The combustor of the gas turbine according to claim 1 or 2.
  4. 　前記駆動回路は、前記駆動信号における周波数を変更可能である、
    ことを特徴とする請求項１乃至３のいずれか一項に記載のガスタービンの燃焼器。     The drive circuit can change the frequency in the drive signal.
    The combustor of the gas turbine according to any one of claims 1 to 3, wherein the combustor of the gas turbine.
  5. 　前記DBDプラズマアクチュエータの一対の電極は環状であって、誘電体の環状板の両面にそれぞれ配置されている、
    ことを特徴とする請求項１乃至４のいずれか一項に記載のガスタービンの燃焼器。     The pair of electrodes of the DBD plasma actuator are annular and are arranged on both sides of an annular plate of a dielectric.
    The combustor of the gas turbine according to any one of claims 1 to 4, wherein the combustor of the gas turbine.
  6. 　内部が燃焼室である筒状のダクト部と、混合ガスを前記燃焼室の入口から前記燃焼室内
    に供給する供給装置と、前記燃焼室の入口に配置された、一対の電極を備えたDBDプラズマアクチュエータと、を備えたガスタービンの燃焼器の燃焼制御方法であって、
    　前記ダクト部内の圧力を検出して、圧力信号を出力し、
    　前記圧力信号に基づいて、所定のデューティ比を持つ駆動信号を前記電極に入力し、
    　前記圧力波形の平均をゼロ点としたとき前記圧力波形の変動が負から正になるときに通過する前記ゼロ点を位相の基準点として、前記基準点に対する駆動位相θｄが存在し、前記圧力信号に対応する圧力波形の１周期を２πとし、ｎを０以上の整数としたときに、前記圧力信号の入力から（２ｎπ＋θｄ）経過後に前記DBDプラズマアクチュエータを間欠駆動させ、
    　前記所定の駆動位相は、０以上でπ以下、もしくは7π/4以上で２π以下である、
    ことを特徴とするガスタービンの燃焼器の燃焼制御方法。     A DBD plasma having a tubular duct portion whose inside is a combustion chamber, a supply device for supplying mixed gas from the inlet of the combustion chamber to the combustion chamber, and a pair of electrodes arranged at the inlet of the combustion chamber. A combustion control method for a gas turbine combustor equipped with an actuator.
    The pressure in the duct portion is detected, a pressure signal is output, and the pressure signal is output.
    Based on the pressure signal, a drive signal having a predetermined duty ratio is input to the electrode.
    When the average of the pressure waveform is set to the zero point, the driving phase θd with respect to the reference point exists with the zero point passing when the fluctuation of the pressure waveform changes from negative to positive as the reference point of the phase, and the pressure signal. When one cycle of the pressure waveform corresponding to is 2π and n is an integer of 0 or more, the DBD plasma actuator is intermittently driven after (2nπ + θd) has elapsed from the input of the pressure signal.
    The predetermined drive phase is 0 or more and π or less, or 7π / 4 or more and 2π or less.
    A combustion control method for a gas turbine combustor.
PCT/JP2020/017011 2019-05-10 2020-04-20 Burner for gas turbine, and method for controlling combustion in same WO2020230531A1 (en)

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6210615B2 (en) * 1980-10-22 1987-03-07 Kubota Ltd
JP2016166727A (en) * 2015-02-27 2016-09-15 ゼネラル エレクトリック テクノロジー ゲゼルシャフト ミット ベシュレンクテル ハフツングＧｅｎｅｒａｌ Ｅｌｅｃｔｒｉｃ Ｔｅｃｈｎｏｌｏｇｙ ＧｍｂＨ Method and device for flame holding in burner system of stationary combustion engine

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6210615B2 (en) * 1980-10-22 1987-03-07 Kubota Ltd
JP2016166727A (en) * 2015-02-27 2016-09-15 ゼネラル エレクトリック テクノロジー ゲゼルシャフト ミット ベシュレンクテル ハフツングＧｅｎｅｒａｌ Ｅｌｅｃｔｒｉｃ Ｔｅｃｈｎｏｌｏｇｙ ＧｍｂＨ Method and device for flame holding in burner system of stationary combustion engine

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