JPH06229545A - Burner - Google Patents

Abstract

PURPOSE:To suppress vibrating combustion irrespective of a load change of a combustion and exhaust variation by calculating a signal to be optimally suppressed by antiphase interference by a sound base based on a pressure change generated by the combustion and outputting sound wave of the antiphase to a burner by the signal. CONSTITUTION:A variation in a pressure of combustion sound is detected as a sound pressure by a first pressure detector 21 provided in a burner 12, and an antiphase signal of the sound is calculated by a calculator 25 based on the signal. An antiphase sound wave is generated from a silencing speaker 26 provided in the burner 12, vibration of a flame 16 is suppressed to silence the combustion sound therein. Further, a varying combustion sound is always minimized by an adaptive control for evaluating a silencing amount based on a signal of a second pressure detector 22 of a combustion chamber 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion device having a function of actively muffling combustion noise of a combustion device for burning gas etc. by calculating a signal having a phase opposite to the sound pressure generated by the noise. It is about.

[0002]

2. Description of the Related Art A conventional combustion apparatus will be described with reference to a gas water heater shown in FIG. As shown in FIG. 8, a blower 1 for supplying combustion air, a fuel control device 2 for controlling fuel,
A burner unit 3 that mixes fuel and air to form an air-fuel mixture, a combustion chamber 4 in which the air-fuel mixture ejected from the burner unit 3 burns, and an exhaust passage 5 that discharges exhaust gas generated by combustion to the outside of the device.
The exhaust port 6, the sound absorbing material 7 provided in the exhaust passage 5, and the main body 8. Here, 9 is a heat exchanger that transfers the heat of combustion to water.

In the above structure, noise generated when the gas water heater is operated is roughly classified into blast noise generated from the blower 1 and combustion noise generated by combustion. Here, these noises were mainly reduced by the sound deadening effect of the sound absorbing material 7 of the exhaust passage 5 discharged from the exhaust port 6 and the sound insulating effect of the main body 8.

[0004]

However, in the above-mentioned conventional structure, the blast noise could be reduced to some extent by the sound absorbing effect and the sound insulating effect, but the combustion noise mainly composed of low frequency could not be reduced. That is, in order to reduce the low frequency noise, the exhaust passage 5 must be made very large and a large amount of the sound absorbing material 7 must be used, which is a problem that it is actually difficult to realize. Furthermore, depending on the combustion load fluctuations and exhaust variation, combustion noise resonates with the space inside the combustion device and is excited to generate a very large noise called oscillatory combustion, which requires a lot of time for burner design and a large number of burners. There was a problem that I had to make.

The present invention solves the above-mentioned problems. The combustion noise generated when the combustion apparatus is operated is significantly reduced by the active noise reduction, and the variation of the combustion noise is adaptively controlled so that the noise is reduced. The purpose is to maintain the effect and completely suppress oscillating combustion regardless of fluctuation of combustion load and exhaust variation.

[0006]

To achieve the above object, the first technical means of the combustion apparatus of the present invention is a blower for supplying air, a fuel controller for supplying fuel, and a mixture of air and fuel. A burner part, an air flow path for connecting the blower device and the burner part to flow air, a fuel flow path for connecting the fuel control device and the burner part to flow fuel, and burning the mixed gas mixed in the burner part A combustion chamber, an exhaust passage for discharging exhaust gas from the combustion chamber, a first pressure detector for detecting the pressure of the burner portion, a second pressure detector for detecting the pressure of the combustion chamber, and a first And a burner for calculating, by adaptive control, a signal in which the pressure in the vicinity of the second pressure detector is suppressed by the anti-phase interference due to the sound wave based on the signal of the pressure detector and the signal of the second pressure detector. It is provided with a sound wave generating means for generating a sound wave in its section. .

The second technical means of the combustion apparatus of the present invention comprises a sound wave generating means for generating a sound wave in the air flow path.

The third technical means of the combustion apparatus of the present invention comprises a sound wave generating means for generating a sound wave in the fuel flow path.

The fourth technical means of the combustion apparatus of the present invention comprises a sound wave generating means for generating a sound wave in the exhaust passage.

[0010]

According to the present invention, due to the above-described structure, first, the combustion causes a pressure fluctuation in the combustion chamber. This pressure fluctuation propagates to the burner section, the air flow passage, the fuel flow passage, and further to the exhaust passage. In the first pressure detector attached to the burner part,
The pressure fluctuation due to this combustion is detected. This signal is taken into the arithmetic unit, and the arithmetic unit calculates a signal having a reverse phase of this signal and outputs it as a sound wave from the sound wave generating means provided in the burner section. The pressure fluctuation of the air-fuel mixture in the burner section is reduced due to the phase interference caused by the opposite phase sound waves emitted from the sound wave generating means. As a result, the vibration of the flame generated by combustion disappears, and the combustion noise is reduced. Further, the combustion noise in the combustion chamber is detected by the second pressure detector and is taken into the arithmetic unit. The computing device determines the muffling effect of the combustion noise, and when the muffling volume is low, adjusts the phase and output of the anti-phase signal,
Try to maximize the mute volume. That is, the signal processing in the arithmetic unit incorporates an adaptive control algorithm so as to follow up even when the combustion sound changes, and calculates the inverse characteristic of the combustion sound in real time.

Further, in the structure in which the sound wave generating means is provided in the air flow path, the antiphase sound of the combustion sound is radiated to the combustion air.
The combustion noise in the air flow path is canceled out. As a result, the vibration of the flame generated by combustion disappears, and the combustion noise is reduced.

Further, in the structure in which the sound wave generating means is provided in the fuel flow path, the combustion noise in the fuel flow path is canceled out because the anti-phase sound of the combustion sound is emitted to the fuel. As a result, the vibration of the flame generated by combustion disappears, and the combustion noise is reduced.

Further, in the structure in which the sound wave generating means is provided in the exhaust passage, the antiphase sound of the combustion sound is directly radiated to the flame,
The combustion noise in the exhaust passage is canceled and the vibration of the flame disappears. This reduces the combustion noise emitted from the exhaust port to the outside of the combustion device.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the gas water heater shown in FIGS.

As shown in FIGS. 1 and 3, a sirocco fan 10 which is a blower for supplying combustion air, a proportional valve 11 which controls the amount of combustible gas which is fuel, and a burner which mixes combustible gas and air. Section 12, an air flow path 13 that connects the sirocco fan 10 and the burner section 12 and supplies air, a fuel flow path 14 that connects the proportional valve 11 and the burner section 12 and supplies a combustible gas, and burns an air-fuel mixture. Combustion chamber 15 and flame 16
An exhaust passage 17 for exhausting combustion gas to the outside of the device, an exhaust port 18, and a heat exchanger 19 for transferring the heat of combustion to water. Then, a pressure tap 20 provided in each of the burner section 12 and the combustion chamber 15 in order to take out a pressure fluctuation generated by combustion, and a first microphone which is a first pressure detector for detecting the sound pressure of the burner section 12. 21 and the combustion chamber 15
Second microphone 22 which is a second pressure detector for detecting the sound pressure of each, a tube 23 connecting each pressure tap 20 and the first and second microphones 21 and 22, and a glass wool provided inside each tube 23. 24, an arithmetic unit 2 for calculating a signal in which the sound pressure of the second microphone 22 is suppressed by the antiphase interference due to the sound wave based on the signals of the first microphone 21 and the signal of the second microphone 22.
5 and a muffling speaker 26 as a sound wave generating means for generating a sound wave having an opposite phase by the signal of the arithmetic unit 25.
Be prepared for. Further, the arithmetic unit 25 is similar to that shown in FIG.
From the first amplifier 27 that amplifies the signal of the first microphone 21, the first A / D converter 28 that converts an analog signal into a digital signal, and the first A / D converter 28 Digital filter device 29 for calculating an inverse characteristic based on the signal of the second microphone, a second amplifier 30 for amplifying the signal of the second microphone 22, and a second A / D converter 31.
An adaptive filter device 32 for evaluating the volume of the combustion noise based on the signal from the second A / D converter 31, and a D / A converter 33 for converting the calculated digital anti-phase signal into an analog signal. And a third amplifier 34 for amplifying this signal.

According to the above construction, the pressure fluctuation generated by combustion is transmitted to the burner section 12, detected as sound pressure by the first microphone 21, and taken into the arithmetic unit 25. In the arithmetic unit 25, the captured signal is amplified by the first amplifier 27, converted into a digital signal by the first A / D converter 28, and then captured by the digital filter unit 29. An anti-phase signal of the combustion sound is calculated based on this signal. The calculated anti-phase signal passes through the adaptive filter device 32, is converted into an analog signal by the D / A converter 33, is amplified by the third amplifier 34, and is output from the muffling speaker 26 provided in the burner unit 12. Then, the combustion noise in the burner unit 12 is silenced by phase interference. As a result, the vibration of the flame generated by combustion can be suppressed, so that the combustion noise of the gas water heater discharged from the exhaust port 18 can be reduced, and the occurrence of oscillatory combustion can be prevented. Further, the second microphone 22 provided in the combustion chamber 15 evaluates the sound deadening of the combustion sound. That is, the second microphone 2
The signal detected in 2 is amplified by the second amplifier 30, converted into a digital signal by the second A / D converter 31, and then passed through the digital filter device 29 and taken into the adaptive filter device 32. In the adaptive filter device 32, the filter coefficient is changed so that the combustion noise is minimized, the phase and the gain of the output signal are adjusted, and the adaptive control that constantly minimizes the changing combustion noise is executed. Here, the first and second microphones 21 and 22 include a pressure tap 20 and a tube 23.
While the sound pressure is detected via the, and the glass wool 24 is filled in the tube 23, the standing wave resonance generated in the tube 23 can be suppressed and the sound pressure signal can be faithfully detected.

It is difficult to reduce low-frequency noise (100 to 300 Hz), which is the main band of combustion noise, by the conventional sound insulation and sound absorption methods for reducing combustion noise, because vibration combustion is suppressed for each exhaust variation. Burner design was required. On the other hand, according to the present invention, the combustion noise can be significantly reduced by the above action, and the fluctuation of the combustion load,
Oscillating combustion caused by exhaust variation can be completely suppressed with one burner design. That is, the time required for burner design can be shortened.

Next, the second technical means of the present invention will be described with reference to FIG.
It will be explained based on. The parts having the same structure as those of the first embodiment and having the same function are designated by the same reference numerals, and detailed description thereof will be omitted, and different parts will be mainly described. The sirocco fan 10 which is a blower for supplying combustion air, the proportional valve 11 which controls the amount of combustible gas which is fuel, the burner portion 12 which mixes the combustible gas and air, and the sirocco fan 10 and the burner portion 2 are communicated with each other. Air flow path 13 for supplying squeezing air and proportional valve 1
1 for communicating combustible gas with the burner section 12, a combustion chamber 15 for burning the air-fuel mixture, an exhaust passage 17 and an exhaust port 18 for discharging the combustion gas to the outside of the equipment, and heat generated by the combustion. It is composed of a heat exchanger 19 for transmitting water, and is provided with a muffling speaker 26 in the air flow path 13. With the above-described configuration, the mute speaker 26 provided in the air flow path 13 outputs an anti-phase sound of the combustion sound, and the combustion sound in the air flow path 13 is silenced by phase interference. As a result, the combustion noise can be internally silenced by suppressing the vibration of the flame 16 generated by the combustion, the combustion noise of the gas water heater discharged from the exhaust port 18 can be reduced, and the vibration combustion can be prevented in advance. Furthermore, even if a leak occurs from the portion connecting the sound wave generating means and the air flow path 13, it is safe because it is not a mixture.

Next, the third technical means of the present invention will be described with reference to FIG.
It will be explained based on. The parts having the same structure as those of the first embodiment and having the same function are designated by the same reference numerals, and detailed description thereof will be omitted, and different parts will be mainly described. The sirocco fan 10 which is a blower for supplying combustion air, the proportional valve 11 which controls the amount of combustible gas which is fuel, the burner portion 12 which mixes the combustible gas and air, and the sirocco fan 10 and the burner portion 12 are connected to each other. Air flow path 13 for supplying slag air, a fuel flow path 14 for connecting the proportional valve 11 and the burner section 12 to supply a combustible gas, a combustion chamber 15 for combusting an air-fuel mixture, and discharging the combustion gas to the outside of the device. The fuel passage 14 includes an exhaust passage 17, an exhaust port 18, and a heat exchanger 19 that transfers heat generated by combustion to water. With the above configuration, the muffler speaker 26 provided in the fuel flow path 14 outputs the anti-phase sound of the combustion sound, and the combustion sound in the fuel flow path 14 is muffled by phase interference. As a result, the combustion noise can be internally silenced by suppressing the vibration of the flame 16 generated by the combustion, the combustion noise of the gas water heater discharged from the exhaust port 18 can be reduced, and the vibration combustion can be prevented from occurring. Further, the combustion noise can be reduced with a signal smaller than that of giving an antiphase signal to air having a large fuel-air ratio.

Next, the fourth technical means of the present invention will be described with reference to FIGS. 6 and 7. The parts having the same structure as those of the first embodiment and having the same function are designated by the same reference numerals, and detailed description thereof will be omitted, and different parts will be mainly described. A sirocco fan 10 that is a blower that supplies combustion air, a proportional valve 11 that controls the amount of combustible gas that is a fuel, a burner unit 12 that mixes combustible gas and air, and a sirocco fan 10
An air flow path 13 for communicating air between the burner section 12 and the burner section 12
A fuel flow path 14 for supplying a combustible gas through the proportional valve 11 and the burner section 12, and a combustion chamber 15 for burning the air-fuel mixture,
Exhaust passage 17 and exhaust port 18 for discharging to the outside of combustion gas equipment
And a heat exchanger 19 that transfers the heat of combustion to water,
The muffler speaker 26 as a sound wave generating means is provided in the exhaust passage 17
In addition to covering the noise reduction speaker 26 with the speaker box 35, a heat-resistant thin diaphragm 36 is provided between the exhaust passage 17 and the noise reduction speaker 26. With the above-mentioned configuration, the anti-phase sound of the combustion sound is excited from the muffling speaker 26 to vibrate the thin diaphragm 36, and the thin diaphragm 36 causes the exhaust passage 17
The vibration of the flame 16 is directly suppressed by reducing the internal combustion noise. Since the anti-phase sound of the combustion sound reproduced by the muffler speaker 26 is radiated into the exhaust passage 17 through the thin diaphragm 36, the reproduction performance of high frequency is lowered but the combustion sound is low frequency. Therefore, it does not affect the muffling characteristics,
The durability of the muffling speaker 26 does not deteriorate due to heat. As a result, the combustion noise can be silenced internally, the combustion noise of the gas water heater coming from the exhaust port 18 can be reduced, and the occurrence of oscillatory combustion can be prevented in advance.

[0021]

As described above, in the combustion apparatus of the present invention, the pressure fluctuation generated by combustion is detected by the first pressure detector provided in the burner section, and the second pressure detector is based on this signal. The pressure is always optimally suppressed by the anti-phase interference due to the sound wave, the signal is calculated by the adaptive control law, and the sound wave generating means outputs the opposite-phase sound wave to the burner section. Since the combustion noise that occurs is reduced by phase interference and the vibration of the flame that occurs due to combustion can be suppressed, the combustion noise of the gas water heater that exits from the exhaust port can be reduced, and the occurrence of oscillatory combustion can be prevented in advance. Furthermore, since the fluctuation in combustion load and oscillating combustion caused by exhaust variation can be completely suppressed by one burner design, the time required for burner design can be greatly shortened.

Further, in the structure in which the sound wave generating means is provided in the air flow path, even if a leak occurs from the portion connecting the sound wave generating means and the air flow path, it is safe because it is not an air-fuel mixture, and combustion noise can be reduced. Occurrence of oscillatory combustion can be prevented.

Further, in the structure in which the sound wave generating means is provided in the fuel flow path, since the sound wave generating means gives the anti-phase signal to the fuel, the combustion noise is generated with a signal smaller than that of giving the anti-phase signal to the air having a large fuel-air ratio. And the occurrence of oscillatory combustion can be prevented in advance.

Further, in the structure in which the sound wave generating means is provided in the exhaust passage, the sound wave of the antiphase signal is directly applied to the flame on the downstream side of the combustion chamber, so that the vibration of the flame can be easily suppressed, the combustion noise can be reduced, and Combustion can be prevented in advance.

[Brief description of drawings]

FIG. 1 is a front view of a gas water heater using a combustion device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an internal configuration of an arithmetic unit in the same device.

FIG. 3 is an enlarged sectional view of a pressure detector of the device.

FIG. 4 is a front view of a gas water heater using a combustion device according to another embodiment of the present invention.

FIG. 5 is a front view of a gas water heater using a combustion apparatus according to still another embodiment of the present invention.

FIG. 6 is a side sectional view of a gas water heater using a combustion device according to yet another embodiment of the present invention.

FIG. 7 is an enlarged cross-sectional view of a sound wave generating means of the device.

FIG. 8 is a side sectional view of a conventional gas water heater.

[Explanation of symbols]

 10 Blower device 11 Fuel control device 12 Burner part 13 Air flow path 14 Fuel flow path 15 Combustion chamber 17 Exhaust passage 21 First pressure detector 22 Second pressure detector 25 Arithmetic device 26 Sound wave generating means

Claims (4)

[Claims] 1. A blower device for supplying air, a fuel control device for supplying fuel, and a burner section for mixing air and fuel.
An air flow path that connects the blower unit and the burner section to flow air, a fuel flow path that connects the fuel control apparatus and the burner section to flow fuel, and burns a mixed gas mixed in the burner section. A combustion chamber, an exhaust passage for discharging exhaust gas from the combustion chamber, a first pressure detector for detecting the pressure of the burner portion, and a second pressure detector for detecting the pressure of the combustion chamber. , A signal in which the pressure in the vicinity of the second pressure detector is suppressed by the anti-phase interference due to the sound wave is calculated by the adaptive control based on the signal of the first pressure detector and the signal of the second pressure detector. And a sound wave generating means for generating the sound wave in the burner section. 2. A blower device for supplying air, a combustion control device for supplying fuel, a burner section for mixing air and fuel,
An air flow path that connects the blower unit and the burner section to flow air, a fuel flow path that connects the fuel control apparatus and the burner section to flow fuel, and burns a mixed gas mixed in the burner section. A combustion chamber, an exhaust passage for discharging exhaust gas from the combustion chamber, a first pressure detector for detecting the pressure of the burner portion, and a second pressure detector for detecting the pressure of the combustion chamber. , A signal in which the pressure in the vicinity of the second pressure detector is suppressed by the anti-phase interference due to the sound wave is calculated by the adaptive control based on the signal of the first pressure detector and the signal of the second pressure detector. And a sound wave generating means for generating the sound wave in the air flow path. 3. A blower device for supplying air, a fuel control device for supplying fuel, a burner section for mixing air and fuel,
An air flow path that connects the blower unit and the burner section to flow air, a fuel flow path that connects the fuel control apparatus and the burner section to flow fuel, and burns a mixed gas mixed in the burner section. A combustion chamber, an exhaust passage for discharging exhaust gas from the combustion chamber, a first pressure detector for detecting the pressure of the burner portion, and a second pressure detector for detecting the pressure of the combustion chamber. , A signal in which the pressure in the vicinity of the second pressure detector is suppressed by the anti-phase interference due to the sound wave is calculated by the adaptive control based on the signal of the first pressure detector and the signal of the second pressure detector. And a sound wave generating means for generating the sound wave in the fuel flow path. 4. A blower device for supplying air, a fuel control device for supplying fuel, a burner section for mixing air and fuel,
An air flow path that connects the blower unit and the burner section and through which air flows, a fuel flow path that connects the fuel control apparatus and the burner section and through which fuel flows, and burns a mixed gas mixed in the burner section. A combustion chamber, an exhaust passage that discharges exhaust gas from the combustion chamber, a first pressure detector that detects the pressure of the burner portion, and a second pressure detector that detects the pressure of the combustion chamber, Based on the signal of the first pressure detector and the signal of the second pressure detector, a signal in which the pressure in the vicinity of the second pressure detector is suppressed by antiphase interference due to sound waves is calculated by adaptive control. A combustion device comprising a computing device and a sound wave generation unit that is provided in the exhaust passage and generates the sound wave signal.