JP2000039107A - Forcedly oscillated combustor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the serviceability of a forcedly oscillated combustor and, at the same time, to reduce the cost of the combustor, by installing a fluid element which pulsates the flow rate of a fluid flowing out from the output port of the element by causing oscillation when the fluid flows in the element through its supply port to a fuel supply path, an oxygen-containing gas supply path for combustion, or a mixer supply path. SOLUTION: A fluid element 5 is installed to a fuel supply path 2 as a pulsation generating means which pulsates the flow rate of fuel (g) sent to a burner 1 at a prescribed frequency. Then the difference corresponding to the half of the pulsating wavelength of a liquid g' passing a first output duct 7a side is given to the lengths of the first output duct 7a and a second output duct 7b, so that the pulsating waveform of the liquid g' may be superimposed upon that of another liquid g" passing on the second duct 7b side at the junction of the ducts 7a and 7b. Therefore, the forced oscillation combustion of a forcedly oscillation combustor can be stabilized by pulsative combustion of the burner 1 in which the state of combustion of the burner 1 is pulsatively changed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forced vibration combustor for use in, for example, an industrial furnace or a boiler.
The pulsation generating means pulsates the flow rate of the fuel sent to the combustion section, or the flow rate of the oxygen-containing gas for combustion sent to the combustion section, or the flow rate of the mixture of the fuel and the oxygen-containing gas sent to the combustion section, to change the combustion state. The present invention relates to a pulsatingly changing forced vibration combustor.

[0002]

2. Description of the Related Art In a forced oscillation combustor, if an appropriate value is set for the frequency of the above-mentioned pulsation, NOx may be generated due to time-series combustion of light and shade combustion or occurrence of a pulsating excess fuel state.
x reduction effect or combustion in a diluted state in the furnace atmosphere (EGR) to provide effective NO
It is known that the effect of reducing x can be obtained, and that the boundary film on the heat transfer surface is destroyed by the pulsation of combustion, so that the heat transfer property in the combustion gas heat exchange section can be effectively improved (for example, US Pat. Conventionally, in this type of forced vibration combustor, a valve or a diaphragm is used as a pulsation generating means, and the pulsation is generated by opening / closing of the valve or vibration of the diaphragm.

[0003]

However, if pulsation of an effective frequency (for example, several Hz to several tens of Hz) is generated by means having a mechanically movable part such as a valve or a diaphragm, the movable part cannot be used. Due to problems such as fatigue, abrasion, and seizure, it is difficult to obtain sufficient durability for practical use.In addition, a drive mechanism that opens and closes the valve in a short cycle and vibrates the diaphragm requires high equipment costs. There was a sticking problem.

[0004] In view of this situation, the main problems of the present invention are:
The problem is to solve the above problem effectively by adopting a rational pulsation generation method.

[0005]

Means for Solving the Problems [1] In the invention according to claim 1, the flow rate of the fuel sent to the combustion section, the flow rate of the oxygen-containing gas for combustion sent to the combustion section, or the fuel sent to the combustion section is determined. In order to change the combustion state pulsatingly by pulsating the flow rate of the air-fuel mixture with the pulsation generating means by the pulsation generating means, pulsation occurs in the flow rate of the outflow fluid from the output port due to oscillation caused by the inflow of the fluid from the supply port. The fluid element that causes the above is interposed as a pulsation generating means in a fuel supply path to the combustion section, a combustion oxygen-containing gas supply path, or a mixture supply path.

In other words, in this configuration, the fuel or the oxygen-containing gas for combustion or a mixture thereof is supplied to the combustion section through the fluid element, so that the pulsation of the outflow fluid flow rate due to the oscillating action of the fluid element causes the combustion section to pulsate. Pulsating the flow rate of the fuel or combustion oxygen-containing gas or air-fuel mixture sent to the
This causes the combustion section to perform oscillating combustion that pulsates the combustion state.

[0007] If a system utilizing the oscillating action of the fluidic element is employed, pulsation of a required frequency can be generated accurately and stably without the need for a mechanically movable part and a driving mechanism, and desired oscillating combustion is performed. It works well,
Compared with a conventional device that generates pulsation using a valve or a diaphragm, the durability can be greatly improved and the device cost can be greatly reduced.

[2] In the invention according to claim 2, as the fluid element, a state in which a main flow of the inflowing fluid flows out of the first output port and a state of flowing out of the second output port as the fluid flows in from the supply port. The fluid element is alternately switched in an oscillating state. This fluid element is connected to two parts of the combustion part by branching a fuel supply path or a combustion oxygen-containing gas supply path or a mixture supply path. And a fuel or an oxygen-containing gas for combustion or an air-fuel mixture are alternately supplied to two portions of these combustion portions.

That is, in this configuration, the fuel or the oxygen-containing gas for combustion or the air-fuel mixture is alternately supplied to the two portions of the combustion portion by using the oscillation action of the fluid element as described above, so that the two portions of the combustion portion are provided. The fuel or the oxygen-containing gas for combustion or the flow rate of the air-fuel mixture to be sent to the combustion unit is pulsated in a state in which the pulsation phases are inverted, so that combustion is performed in the two parts of these combustion units in a state in which the pulsation phases are inverted. An alternating-combustion oscillating combustion that changes the state in a pulsating manner is performed.

[0010] With this configuration, the combustion section has two parts that need to be individually supplied with fuel or oxygen-containing gas for combustion or an air-fuel mixture from the point of view of use or the like. In a state in which the fluid element of the general type having the above is reasonably used, the above-described alternating combustion oscillating combustion can be easily realized in terms of configuration.

The combustion system in which the combustion section has two parts that require separate supply of fuel or combustion oxygen-containing gas or air-fuel mixture uses combustion air (an example of combustion oxygen-containing gas). A two-stage combustion system in which fuel is supplied to each of an upstream portion and a downstream portion in a region, a two-stage combustion system in which fuel is supplied to each of an upstream portion and a downstream portion in a combustion region, or a mixture is supplied to one region of a combustion region. A combustion system supplied from both the side portion and the other side portion can be used.

[3] In the invention according to claim 3, the first combustion section and the second combustion section are alternately arranged adjacent to each other in an adjacent state,
As the fluid element, an element is used which is alternately switched in an oscillating state between a state in which the main flow of the inflowing fluid flows out of the first output port and a state in which the main flow of the inflowing fluid flows out of the second output port with the inflow of the fluid from the supply port. A branch portion of a fuel supply path or an oxygen-containing gas for combustion that branches and connects a fluid element to a group of a first combustion portion and a group of a second combustion portion in a side-by-side group of a first combustion portion and a second combustion portion. A configuration in which the fuel or the oxygen-containing gas for combustion or the air-fuel mixture is alternately supplied to the first combustion unit group and the second combustion unit group by being interposed at the branch of the supply path or the branch of the air-fuel mixture supply path. I do.

That is, in this configuration, the fuel or the oxygen-containing gas for combustion or the air-fuel mixture is supplied to the first combustion unit and the second combustion unit in the side-by-side group by using the oscillation action of the fluid element as described above. By alternately supplying the combustion unit group and the second combustion unit group, the flow rates of the fuel or the oxygen-containing gas for combustion or the air-fuel mixture to be sent to the first combustion unit group and the second combustion unit group are mutually pulsation phases. Are pulsated in a state in which the first combustion section and the second combustion section are alternately positioned in an adjacent state.
Alternating oscillating combustion in which the combustion state pulsates is performed in a state where the pulsation phases are inverted.

By virtue of the fact that the first combustion section and the second combustion section which are alternately positioned in the adjacent state perform the oscillating combustion in an alternating combustion manner as compared with the simple combustion combustion in one combustion section, , The adjacent first combustion section and the second
Oscillation combustion as a whole can be further stabilized by the mutual combustion assisting effect between the combustion unit and the combustion section, and thus, NOx reduction, which is an advantage of forced oscillation combustion, can be more effectively achieved.

[0015] With this configuration, similarly to the above-described second aspect of the present invention, the above-described combustion units are juxtaposed with the general type of fluid element having two output ports being rationally used. Oscillating combustion like alternating combustion in a group can be easily realized in configuration.

[4] In the invention according to claim 4, a state in which fuel or oxygen-containing gas for combustion or an air-fuel mixture is guided to the combustion section through the fluid element, and a state in which the fluid element is bypassed to the combustion section. And switching means for switching the flow path.

That is, in this configuration, when the combustion operation is started, first, the fuel or the oxygen-containing gas for combustion or the air-fuel mixture is bypassed to the fluid element and guided to the combustion section side, and the pulsation as described above is performed. After the combustion operation is started in a continuous combustion mode in which no combustion occurs, the combustion region temperature is sufficiently increased by the continuous combustion, and then the fuel or the oxygen-containing gas for combustion or the air-fuel mixture is supplied to the combustion section through the fluid element by the switching means. By bringing the combustion operation to the side, the combustion operation can be shifted from continuous combustion to forced oscillation combustion using the oscillation action of the fluid element.

The desired forced oscillation combustion can be stably started by shifting to the forced oscillation combustion after sufficiently increasing the temperature of the combustion region by the continuous combustion as described above. Even higher device performance can be obtained.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Example) FIG. 1 shows an example in which forced oscillation combustion is performed by pulsating the flow rate of fuel, 1 is a burner constituting a combustion section, and 2 is a fuel g to a burner 1. A fuel supply path 3 for sending the combustion air a (an example of an oxygen-containing gas for combustion) to the burner 1 is a combustion gas supply path for sending out a combustion gas e generated in the burner 1, The generated combustion gas e is used for various heating purposes such as heating in a furnace and fluid heating by a heat exchanger.

Reference numeral 5 denotes a fluid element interposed in the fuel supply path 2 as pulsation generating means for pulsating the flow rate of the fuel g sent to the burner 1 at a predetermined frequency.
With the inflow of fluid (in this example, the inflow of the fuel g), the state in which the main flow of the inflow fluid g flows into the first output duct 7a and the state in which it flows into the second output duct 7b are alternately switched in an oscillating state. Instead, a fluidic oscillation element of a side wall attached type which flows out from one output port 8 and is improved is adopted.

The improvement of the element 5 is that the first output duct 7
At the confluence of a and the second output duct 7b, as shown in FIG. 2, the pulsation waveform of the fluid g 'passing through the first output duct 7a and the fluid g "passing through the second output duct 7b
So that the pulsation waveform of the first output duct 7a
Is given to the duct length of the second output duct 7b by a difference corresponding to a half wavelength of the pulsation waveform, whereby the fluid g flowing out of the output port 8 (that is, the burner 1
The flow rate of the fuel to be fed to the pulsation is pulsated with an amplified pulsation waveform as shown by the broken line in FIG.

That is, with the above configuration, the flow rate of the fuel sent to the burner 1 is pulsated at a predetermined frequency by the oscillating action of the fluid element 5 (in other words, the air-fuel ratio in the burner 1 is pulsated). Oscillating combustion is performed to change the combustion state in a pulsating manner.

A switching valve 9 switches the fuel flow path between a state in which the fuel g is sent to the burner 1 through the fluid element 5 as a pulsation generating means and a state in which the fuel g is sent to the burner 1 by bypassing the fluid element 5 through the bypass passage 10. When the combustion operation is started, first, the switching valve 9 diverges the fuel g to the fluid element 5 and guides the fuel g to the burner 1 in a continuous combustion mode in which pulsation does not occur as described above. The combustion operation is started, and then, after the combustion zone temperature is sufficiently increased by the continuous combustion, the switching valve 9 switches the fuel g to the state in which the fuel g is guided to the burner 1 through the fluid element 5 to change the combustion from the continuous combustion. Shift to forced vibration combustion. That is,
As described above, the temperature in the combustion region is sufficiently increased by the continuous combustion, and then the process is shifted to the forced oscillation combustion, whereby the forced oscillation combustion is stably started.

The operation of the switching valve 9 is such that when the temperature of the combustion zone rises to a predetermined temperature (for example, the self-ignition temperature of the fuel), the switching valve is switched from the fluid element bypass side to the fluid element passing side based on the detected temperature. 9 or a timer method for automatically switching the switching valve 9 from the fluid element bypass side to the fluid element passing side when a predetermined time has elapsed after the start of combustion operation, or by a manual operation. Various methods such as a method of switching the switching valve 9 can be adopted.

Numeral 11 denotes a flow path for ensuring a minimum flow rate, which is provided as required. By providing this flow path 11, the flow rate of the fuel g sent to the burner 1 in the forced vibration combustion state is minimized as shown in FIG. Pulsation is performed with the flow rate gm secured, thereby stabilizing forced vibration combustion.

(Second Example) FIG. 4 shows an example in which forced oscillating combustion is performed by pulsating the flow rate of the oxygen-containing gas for combustion. In this combustor, the fluid element 5 as pulsation generating means is replaced with a fuel. Instead of being provided in the supply path 2, it is provided in the combustion air supply path 3 (combustion oxygen-containing gas supply path),
With this configuration, the flow rate of the combustion air a sent to the burner 1 is pulsated at a predetermined frequency by the oscillating action of the fluid element 5 (in other words, the air-fuel ratio in the burner 1 is pulsated) to perform oscillating combustion.

Reference numeral 9 'denotes a state in which the combustion air a is sent to the burner 1 through the fluid element 5 as a pulsation generating means, and a state in which the fluid flows through the bypass passage 10' for the same purpose as the switching valve 9 in the combustor shown in FIG. A switching valve for switching the air flow path between a state in which the element 5 is bypassed and the element 5 is sent to the burner 1.

Reference numeral 11 'is a flow passage for ensuring a minimum flow rate provided as needed, similarly to the flow passage 11 in the combustor shown in FIG. 1. By providing this flow passage 11', forced oscillation combustion is performed. In this state, the flow rate of the combustion air a sent to the burner 1 is pulsated in a state in which the minimum flow rate is secured in the same manner as in the pulsation mode shown in FIG. 3, thereby stabilizing forced oscillation combustion.

(Third Example) FIG. 5 shows an example in which forced oscillating combustion is performed by pulsating the flow rate of a mixture of fuel and oxygen-containing gas for combustion. Instead of providing the fluid element 5 in the fuel supply path 2 or the combustion air supply path 3, the fluid element 5 is provided in a mixture supply path 12 for sending a mixture m of the fuel g and the combustion air a to the burner 1. With this configuration, the flow rate of the air-fuel mixture to be sent to the burner 1 is pulsated at a predetermined frequency by the oscillating action of the fluid element 5 to cause oscillating combustion.

9 "is for the same purpose as the switching valves 9 and 9 'in the combustor shown in FIG. 1 and FIG.
This is a switching valve that switches the air-fuel mixture flow path between a state in which the fluid element 5 is bypassed through the bypass path 10 ″ and sent to the burner 1.

Also, 11 "is a flow path for ensuring a minimum flow rate provided as necessary, similar to the flow paths 11, 11 'in the combustor shown in FIGS. 1 and 4, and this flow path 11" is provided. Thus, in the forced vibration combustion state, the flow rate of the air-fuel mixture m sent to the burner 1 is pulsated in a state in which the minimum flow rate is secured in the same manner as in the pulsation mode shown in FIG. 3, thereby stabilizing the forced vibration combustion. .

(Fourth Example) FIG. 6 shows an example in which a forced oscillating combustion is performed in a combustor of a two-stage fuel combustion system, and a burner 1 constituting a combustion part includes an upstream part 1a in a combustion region thereof.
And the fuel g is individually supplied to two portions of the downstream portion 1b. Reference numeral 3 denotes a combustion air supply passage for sending combustion air a to the burner 1, and reference numeral 4 denotes a combustion gas passage for sending out combustion gas e generated in the burner 1.

5 'is pulsation generating means for pulsating the flow rate of fuel sent to the two parts 1a and 1b.
a fluid element interposed at a branch portion of the fuel supply path 2 branching and connecting to the fluid elements a and 1b. This fluid element 5 'is accompanied by fluid inflow from the supply port 6 (in this example, fuel g inflow). , The main flow of the inflow fluid g flows through the first output duct 7a to the first
A general side wall-attached element that alternately switches in an oscillating state between a state of flowing out of the output port 8a and a state of flowing out of the second output port 8b through the second output duct 7b is employed.

That is, according to this configuration, the two portions 1a, 1a of the burner 1 are made using the oscillation action of the fluid element 5 '.
In the form of alternately supplying the fuel g to the b, the flow rates of the fuels g 'and g "to be sent to the respective parts 1a and 1b of the burner 1 are pulsated with their pulsation phases reversed as shown in FIG. As a result, the two portions 1a and 1b of the burner 1 perform the alternating combustion oscillating combustion in which the combustion state is pulsated while the pulsation phases are inverted.

Reference numeral 13 denotes a state in which fuel g is sent to both parts 1a, 1b of the burner 1 through the fluid element 5 ', and a state in which fuel g is sent to both parts 1a, 1b of the burner 1 by bypassing the fluid element 5' through the bypass passage 14. A switching valve (switching means) for switching the fuel flow path. As in the case of the combustor shown in FIGS. The combustion operation is started in a continuous combustion mode in which pulsation is not generated with the element being in a state of being detoured to the element 5 ′ and guided to both portions 1 a and 1 b of the burner 1. Thereafter, the temperature of the combustion region is sufficiently increased by the continuous combustion. Above, by switching the fuel g to the two parts 1a and 1b of the burner 1 through the fluid element 5 'by the switching valve 13, the combustion is shifted from continuous combustion to alternating-combustion forced oscillation combustion.

Reference numeral 15 denotes a flow path for ensuring a minimum flow rate, which is provided as necessary. By providing this flow path 15, the fuel to be sent to each of the parts 1a, 1b of the burner 1 in the forcedly oscillating combustion state of alternating combustion. As shown in FIG. 8, the flow rates of g 'and g "are pulsated while securing the minimum flow rates gm' and gm", thereby stabilizing forced vibration combustion.

(Fifth Example) FIG. 9 shows an example in which forced oscillating combustion is performed in a combustor of a two-stage air combustion system, in which a burner 1 constituting a combustion section includes an upstream portion 1a in its combustion region.
And the combustion air a (an example of an oxygen-containing gas for combustion) is separately supplied to two portions of the fuel cell and the downstream portion 1b.

In this combustor, instead of interposing the fluid element 5 'as pulsation generating means in the fuel supply path 2, a combustion air supply path branched and connected to the two parts 1a and 1b is provided. 3 (oxygen-containing gas supply passage for combustion), the combustion air a is supplied to the two portions 1a and 1b of the burner 1 by using the oscillating action of the fluid element 5 '. In the form of alternate supply, each part 1 of the burner 1
The combustion air a ′, a ″ to be sent to the burners 1 is pulsated in a state where the pulsation phases are inverted in the same manner as in the pulsation mode shown in FIG.
In the above, alternating combustion oscillating combustion for pulsatingly changing the combustion state is performed in a state where the pulsation phases are inverted.

13 'is for the same purpose as the switching valve 13 in the combustor shown in FIG. 6, for sending combustion air a to the two parts 1a and 1b of the burner 1 through the fluid element 5', This is a switching valve for switching the combustion air flow path between a state in which the fluid element 5 'is bypassed and the state is sent to both parts 1a and 1b of the burner 1.

Reference numeral 15 'is a flow path for ensuring a minimum flow rate provided as necessary, similarly to the flow path 15 in the combustor shown in FIG. 6. By providing this flow path 15', an alternating combustion type is provided. In the forced forced combustion state, the flow rate of the combustion air a ', a "sent to each portion 1a, 1b of the burner 1 is pulsated in a state where the minimum flow rate is secured in the same manner as in the pulsation mode shown in FIG. To stabilize forced vibration combustion.

(Sixth Example) FIG. 10 shows an example in which forced-combustion combustion is performed in a combustor of an alternating-mixture combustion type. A burner 1 constituting a combustion part is composed of one side 1a 'in the combustion region and another side. A mixture m of the fuel g and the combustion air a is individually supplied to two portions of the side portion 1b '.

In this combustor, the fluid element 5 'as the pulsation generating means is replaced with the fuel supply path 2 or the combustion air supply path 3 and is replaced with the two parts 1a' and 1b '. The air-fuel mixture m is interposed at a branch portion of the air-fuel mixture supply path 12 which is branched and connected. In the supply mode, the air-fuel mixture m ', m "sent to each portion 1a', 1b 'of the burner 1 is pulsated in a state in which the pulsation phases are inverted, similarly to the pulsation mode shown in FIG. As a result, in the two portions 1a 'and 1b' of the burner 1, an alternating combustion-type oscillating combustion is performed in which the combustion state is pulsated while the pulsation phases are inverted.

13 "is for the same purpose as the switching valves 13 and 13 'in the combustor shown in FIGS. 6 and 9, and the mixture m is supplied to both parts 1a' and 1b 'of the burner 1 through the fluid element 5'. This is a switching valve for switching the air-fuel mixture flow path between a state where the mixture is sent and a state where the mixture is sent to both parts 1a 'and 1b' of the burner 1 by bypassing the fluid element 5 'through the bypass passage 14 ".

Reference numeral 15 "denotes a flow path for ensuring a minimum flow rate provided as necessary, similarly to the flow paths 15, 15 'in the combustor shown in FIGS. 6 and 9, and this flow path 15" is provided. Thus, the flow rate of the air-fuel mixture m ', m "to be sent to the respective portions 1a', 1b 'of the burner 1 in the alternating combustion forced vibration combustion state has secured the minimum flow rate in the same manner as in the pulsation mode shown in FIG. Pulsation is performed in this state, thereby stabilizing forced oscillation combustion.

(Seventh Example) FIG. 11 shows an example in which a forced oscillation combustion is performed by pulsation of a fuel flow rate in a configuration in which a large number of combustion sections are arranged adjacent to each other, and a first burner 1A constituting a first combustion section is provided. The second burners 1B constituting the second combustion section are alternately arranged in parallel and adjacent to each other, and are arranged side by side. Reference numeral 3 denotes a combustion air supply passage for sending combustion air a to each of the burners 1A and 1B.

Reference numeral 5 "denotes a pulsation generating means for pulsating the flow rate of the fuel sent to each of the burners 1A and 1B. The pulsation generating means includes a fuel supply which is branched and connected to the first burner 1A group and the second burner 1B group in the burner juxtaposed group. This fluid element is interposed at the branch of the passage 2 and is connected to the fluid element 5 ″ as the fluid flows in from the supply port 6, similarly to the combustor shown in FIGS. 6, 9 and 10.
A state in which the main flow of the inflow fluid g flows out from the first output port 8a through the first output duct 7a;
A general side wall-attached type element which alternately switches in an oscillating state between a state in which the element flows out of the second output port 8b through the oscillating state is adopted.

That is, with this configuration, the fuel g is alternately supplied to the first burner 1A group and the second burner 1B group in the burner side-by-side group by using the oscillating action of the fluid element 5 ″. The flow rates of the fuels g ′ and g ″ to be sent to the first burner 1A group and the second burner 1B group are pulsated in a state where the pulsation phases are inverted in the same manner as in the pulsation mode shown in FIG.
Thereby, the first burners 1A alternately positioned in the adjacent state.
And the second burner 1B perform alternating combustion-like oscillating combustion in which the combustion state is pulsated while the pulsation phases are inverted.

By causing the first burner 1A and the second burner 1B alternately positioned in the adjacent state to vibrate in an alternating combustion manner, the adjacent first burner 1A and second burner 1B are connected to each other. Stabilize the forced oscillation combustion as a whole by the mutual combustion assist effect between the two.

Numeral 16 designates a fuel flow path between a state where fuel g is sent to each burner 1A and 1B through the fluid element 5 "and a state where fuel g is sent to each burner 1A and 1B by bypassing the fluid element 5" through a bypass passage 17. This is a switching valve (switching means) for switching. Like the previous examples, when starting the combustion operation, the switching valve 16 first diverts the fuel g to the fluid element 5 "and guides the fuel g to each of the burners 1A and 1B. Then, the combustion operation is started in a continuous combustion mode in which pulsation is not generated. After that, the combustion region temperature is sufficiently increased by the continuous combustion, and then the fuel g is supplied by the switching valve 16 to each burner through the fluid element 5 ″. By switching to the state leading to 1A and 1B, the combustion is shifted from continuous combustion to alternating-combustion forced oscillation combustion.

Numeral 18 is a flow path for ensuring a minimum flow rate, which is provided as necessary. By providing this flow path 18, the same as in the previous examples, it is also possible to obtain an alternating-combustion forced vibration combustion state. The flow rates of the fuels g 'and g "to be sent to the first burner group 1A and the second burner group 1B are pulsated in a state where the minimum flow rates gm' and gm" are secured in the same manner as in the pulsation mode shown in FIG. Stabilizes forced oscillation combustion.

(Eighth Example) FIG. 12 shows an example in which pulsation of the combustion air flow rate causes forced oscillating combustion in a configuration in which a large number of combustion sections are arranged side by side. In this combustor, pulsation generation means is used. Instead of interposing the fluid element 5 ″ in the fuel supply path 2, a first burner 1A group and a second burner 1B
The combustion air supply passage 3 (combustion oxygen-containing gas supply passage) is connected to a branch of the combustion air supply passage 3 and is connected to the branch. In a form in which combustion air a is alternately supplied to the first burner 1A group and the second burner 1B group, the flow rate of the combustion air a ', a "sent to the first burner 1A group and the second burner 1B group is adjusted. Similar to the pulsation mode shown in FIG. 7 described above, pulsation is performed in a state where the pulsation phases are inverted with each other, whereby the pulsation phases of the first burner 1A and the second burner 1B that are alternately located in the adjacent state are changed. In an inverted state, an alternating combustion-like oscillating combustion that pulsates the combustion state is performed.

16 'is the combustion air a as in the previous examples.
A switching valve for switching the air flow path between a state in which the fluid element 5 "is sent to each burner 1A, 1B through the fluid element 5" and a state in which the fluid element 5 "is bypassed and sent to each burner 1A, 1B through the bypass path 17 '. 'Is a flow path for ensuring the minimum flow rate that is provided as necessary, as in the previous examples.

(Ninth Example) FIG. 13 shows an example in which forced combustion is performed by pulsation of the air-fuel mixture in a configuration in which a large number of combustion sections are arranged adjacent to each other. Instead of interposing the fluid element 5 ″ in the fuel supply path 2 or the combustion air supply path 3, a branch portion of the mixture supply path 12 that branches and connects to the first burner 1A group and the second burner 1B group And the fluid element 5 "
The air-fuel mixture m is alternately supplied to the first burner 1A group and the second burner 1B group in the burner side-by-side group by using the oscillating action described above, and is sent to the first burner 1A group and the second burner 1B group. The flow rate of the air-fuel mixture m ', m "is pulsated in a state in which the pulsation phases are inverted in the same manner as in the pulsation mode shown in FIG.
Thereby, the first burners 1A alternately positioned in the adjacent state.
And the second burner 1B perform alternating combustion-like oscillating combustion in which the combustion state is pulsated while the pulsation phases are inverted.

16 "indicates a state in which the air-fuel mixture m is sent to each of the burners 1A and 1B through the fluid element 5", as in the previous examples.
A switching valve for switching the air-fuel mixture flow path between a state in which the fluid element 5 "is bypassed through the bypass path 17" and sent to each of the burners 1A and 1B, and 18 "is also provided as necessary, similarly to the previous examples. This is a flow path for ensuring a minimum flow rate.

In the combustor shown in each of FIGS. 11, 12, and 13, a so-called so-called one in which the air excess ratio of one of the adjacent first burner 1A and second burner 1B is set larger than the other. If the concentration combustion method is adopted, higher NOx reduction performance can be obtained by the synergistic effect of the NOx reduction effect by the concentration combustion and the NOx reduction effect by the forced vibration combustion.

[Another Embodiment] Next, another embodiment will be described. The fluid element used as the pulsation generating means is not limited to the side wall-attached type as described above, as long as the fluid element generates oscillation with the inflow of the fluid from the supply port and pulsates the flow rate of the outflow fluid from the output port. Instead, various other types of fluid elements can be applied.

As in each of the above-described examples, instead of providing the fluid element as the pulsation generating means only in one of the fuel supply path, the combustion oxygen-containing gas supply path, or the mixture supply path, Any two or all of these supply paths may be provided with a fluid element.

As the pulsation generating means, the main flow of the inflowing fluid is alternately switched in an oscillating state between a state in which the main flow of the inflowing fluid flows out from the first output port 8a and a state in which the main flow flows out from the second output port 8b as the fluid flows in from the supply port 6. When using a replacement fluid element, FIG.
As shown in the figure, a branching flow path 19 is provided for joining a part of the fluid flowing out of one output port 8b to the fluid flowing out of the other output port 8a, whereby two types of connecting the respective output ports 8a and 8b are provided. May be supplied to the combustion sections 1A and 1B (or the two sections 1a and 1b in the combustion section) by pulsating fuel or oxygen-containing gas or air-fuel mixture at different flow rates. In this case, it is desirable that the path length of the branching / joining channel 19 be set so that the pulsation waveform of the fluid to be merged therewith and the pulsation waveform of the fluid at the merging destination overlap.

As the pulsation generating means, a fluid element which alternately switches in a oscillating state between a state in which the main flow of the inflowing fluid flows out from the first output port and a state in which the main flow flows out from the second output port when the fluid flows in from the supply port In the embodiment described above, in the above-described embodiment, the two types of combustion parts (or two parts in the combustion part) to which these output ports are connected are caused to vibrate in an alternating combustion manner. By setting
In the two kinds of combustion parts (or two parts in the combustion part) to which these output ports are connected, they are oscillated and oscillated synchronously or vibrated in a state where a pulsation waveform is given a phase difference of less than half wavelength or larger than half wavelength. You may make it burn.

Various types of combustion units may be used, including the one-stage combustion system and the two-stage fuel combustion system described in the above embodiment, the two-stage air combustion system and the system in which many combustion units are arranged. Can be applied.

As the fuel, various gaseous fuels such as natural gas and city gas, or various fuels such as liquid fuels can be used. The oxygen-containing gas for combustion is not limited to air.
For example, various oxygen-containing gases such as an oxygen-enriched gas (including pure oxygen) can be used.

The forced vibration combustion apparatus according to the present invention can be used for various applications including an industrial furnace and a boiler.

[Brief description of the drawings]

FIG. 1 is a device configuration diagram showing a first example.

FIG. 2 is a graph showing a pulsation mode.

FIG. 3 is a graph showing a pulsation form in a state where a minimum flow rate is secured.

FIG. 4 is a device configuration diagram showing a second example.

FIG. 5 is a device configuration diagram showing a third example.

FIG. 6 is a device configuration diagram showing a fourth example.

FIG. 7 is a graph showing a pulsation mode.

FIG. 8 is a graph showing a pulsation form in a state where a minimum flow rate is secured.

FIG. 9 is a device configuration diagram showing a fifth example.

FIG. 10 is a device configuration diagram showing a sixth example.

FIG. 11 is a device configuration diagram showing a seventh example.

FIG. 12 is an apparatus configuration diagram showing an eighth example.

FIG. 13 is a device configuration diagram showing a ninth example.

FIG. 14 is an apparatus configuration diagram showing another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Combustion part 1a, 1b Combustion part part 1a ', 1b' Combustion part part 1A First combustion part 1B Second combustion part 2 Fuel supply path 3 Oxygen-containing gas supply path for combustion 5, 5 ', 5 "Fluid element 6 supply Port 8 Output port 8a First output port 8b Second output port 9, 9 ', 9 "Switching means 12 Mixture supply path 13, 13', 13" Switching means 16, 16 ', 16 "Switching means a Combustion oxygen Contained gas g Fuel m Mixture

Claims (4)

[Claims] The pulsation generating means pulsates the flow rate of fuel sent to the combustion section, the flow rate of oxygen-containing gas for combustion sent to the combustion section, or the flow rate of a mixture of fuel and oxygen-containing gas sent to the combustion section. A forced oscillation combustor that changes the combustion state in a pulsating manner by pulsating the fluid element that oscillates with the inflow of fluid from the supply port and causes pulsation in the flow rate of the outflow fluid from the output port. As a means, a forced vibration combustor interposed in a fuel supply path, a combustion oxygen-containing gas supply path, or a mixture supply path to the combustion section. 2. The fluid element alternately switches between a state in which a main flow of the inflowing fluid flows out of a first output port and a state in which the main flow of the inflowing fluid flows out of a second output port as the fluid flows in from a supply port in an oscillation state. An element is used, and the fluid element is interposed at a branch of a fuel supply path, a branch of an oxygen-containing gas supply path for combustion, or a branch of an air-fuel mixture supply path branched and connected to two portions of the combustion section. 2. A forced vibration combustor according to claim 1, wherein fuel or an oxygen-containing gas for combustion or an air-fuel mixture is alternately supplied to two portions of said combustion portion. 3. A first combustion section and a second combustion section are alternately arranged adjacent to each other and arranged side by side. As the fluid element, a main flow of the inflowing fluid is supplied to a first output as the fluid flows in from a supply port. An element that alternately switches in an oscillating state between a state in which the fluid flows out of the mouth and a state in which the fluid flows out of the second output port. The fuel supply passage, the combustion oxygen-containing gas supply passage, or the air-fuel mixture supply passage, which is branched and connected to the first combustion unit group and the second combustion unit group, is interposed. The forced vibration combustor according to claim 1, wherein fuel or a gas containing oxygen for combustion or an air-fuel mixture is alternately supplied to the first combustion unit group and the second combustion unit group. 4. A switching means for switching a flow path between a state in which fuel or an oxygen-containing gas for combustion or an air-fuel mixture is guided to the combustion section through the fluid element and a state in which the fluid element is bypassed and guided to the combustion section. 4. Any one of claims 1 to 3 provided.
A forced vibration combustor according to the paragraph.