JP2002250507A - Burner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a burner on which the temperatures of flames can be detected under a uniform detecting condition even when the burner is operated for burning in a wide capacity range. SOLUTION: Aggregate burner port sections 32, 32, etc., and 32a each of which is composed of many burner ports 31, 31, etc., are formed on the upper surface of a burner plate 3. In the aggregate burner port section 32a positioned below a thermocouple 12 used for detecting the temperatures of burning flames, a specific area 33a composed of the projected area of the thermocouple 13 upon the burner plate 3 and its peripheral area is set as a burner port nonforming area so that the burner may not be influenced directly by the cooling caused by the unburnt portions of the burning flames when the burner is operated for burning with a large capacity or the high temperature from a high-temperature section around the external flames of the burning flames when the burner is operated for burning with a small capacity. It is also possible to form a recessed groove in the specific area 33a and to partially insert the thermocouple 11 into the groove. Alternatively, it is also possible to form burner ports in the specific area 33a at a lower (coarser) density than that of burner ports in the other area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a burner device provided with a temperature detecting means for detecting a flame temperature of a combustion flame for detecting a flame or grasping a combustion state.

[0002]

2. Description of the Related Art Conventionally, as a burner device provided with this kind of temperature detecting means, a thermocouple has been arranged facing a flame hole,
It is generally known that the temperature of the flame of the combustion flame is detected by the thermocouple. In this example, as shown in FIG. 10, a large number of flame holes 31 ', 31',... Are formed in the burner plate 3 'so as to open toward the combustion chamber 9'. , 31 ', ..., a thermocouple 13' is disposed. In this case, the thermocouple 13 ', that is, the area on the burner plate 3' opposite to the thermal junction of the thermocouple 13 'is also provided with the flame holes 31', 31 ',. Are formed so as to open (see FIG. 11).

[0003]

However, according to the above-described conventional burner device, the detection conditions of the thermocouple vary depending on the combustion conditions, and the reliability of the detected temperature may be impaired. In particular, when the burner device is required to perform a combustion operation in a wide capacity range (combustion amount range), it becomes remarkable.

That is, when the fuel is burned with a large capacity, the thermocouple 13 'is positioned in the unburned portion F2 in the combustion flame as shown in FIG. 12 (a), so that the temperature detected by the thermocouple 13' is reduced. May be affected by cooling by unburned gas. On the other hand, in the case of burning with small capacity, FIG.
As shown in FIG. 3B, the thermocouple 13 'comes in contact with the high temperature portion around the active portion F1 where the temperature becomes the highest in the combustion flame, and the thermocouple 13' detects the high temperature at the high temperature portion. Will be done.

On the other hand, in a fuel cell system in which a reformed gas is supplied to a fuel cell, a reformer burner device for heating a reforming catalyst of the reformer is provided in the fuel cell system. For various operation controls, a combustion operation in a wide capacity range may be required rather than a combustion operation with a constant capacity. In order to grasp the combustion state in such a case, it is required to detect the flame temperature under uniform detection conditions.

The present invention has been made in view of such circumstances, and a purpose of the present invention is to provide a burner device capable of detecting a flame temperature under uniform detection conditions even when operating in a wide range of performance. Is to provide.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a burner plate having a large number of flame openings which open to the combustion chamber, and each of the flame openings has a combustion chamber side. The following specific items are provided for a burner device that forms a combustion flame in each of the above-mentioned flame ports by burning the fuel gas ejected to the burner. That is, a temperature detecting means is provided which protrudes into the combustion chamber and detects a flame temperature of a combustion flame formed at the flame port, and a specific area on the burner plate at least opposed to the temperature detecting means is defined as It is a specific matter that the flame outlet density of the flame outlet is set so as to be at least a coarse density compared to other regions. In addition,
The above “to at least coarse density” means “rough”
This includes cases where there is no flame outlet at all.

According to the first aspect of the present invention, regardless of whether the combustion is performed from each flame port on the burner plate with a large capacity or conversely, with a small capacity, The effect is smaller than that in the case where the temperature detecting means is provided at a position facing the other area on the burner plate, because the flame port density is set roughly. For this reason, even if the combustion flame has a large capacity, it is less likely to be affected by the cooling by the unburned gas in the unburned portion. Is difficult to receive directly. This makes it possible to make the conditions for detecting the flame temperature by the temperature detecting means more uniform over a wide range of capabilities.

According to the second aspect of the present invention, there is provided a burner plate having a large number of flame openings facing the combustion chamber, and burning the fuel gas ejected from the respective flame openings toward the combustion chamber. The following specific items are provided for a burner device that forms a combustion flame in a burner. That is, a temperature detecting means is provided which protrudes into the combustion chamber and detects a flame temperature of a combustion flame formed at the flame port, and a specific area on the burner plate at least opposed to the temperature detecting means is defined as It was specified that the flame outlet be a non-formed non-formed area. In addition, the above-mentioned "at least opposing specific regions" means that the region on the burner plate projected when the temperature detecting means is directly opposed to the burner plate is minimized, and the vicinity is around the minimum region. This is intended to include an area where a margin is further added.

According to the second aspect of the present invention, the specific area on the burner plate facing the temperature detecting means is a non-formation area of the flame port, and there is no flame port. Regardless of whether the combustion is performed by the ability or by the small ability, the combustion flame does not directly contact the temperature detecting means and adversely affects the temperature detecting means. That is, even if the combustion flame has a large capacity, it is not affected by the cooling by the unburned gas in the unburned portion unlike the conventional one. It is not directly affected by This makes it possible to more uniformly uniform the conditions for detecting the flame temperature by the temperature detecting means over a wide range of capabilities than in the case of the first aspect.

In the first or second aspect of the present invention, a concave portion is formed in a specific area on the burner plate and opens to the combustion chamber side, and the temperature detecting means is disposed in a state where at least a part thereof is fitted in the concave portion. (Claim 3). In this case, in addition to the uniformity of the detection conditions over the above wide range of capabilities, the temperature detection means of the portion fitted into the concave portion is not exposed to the high temperature portion of the combustion flame, so that the temperature detection means is formed from the viewpoint of durability. There are fewer restrictions on the material to be used. In the case of the third aspect, particularly, when the combustion is performed by narrowing the capacity to a considerably small side,
In other words, even when the combustion flame becomes equal to or smaller than the size of the temperature detecting means, the flame temperature can be reliably detected.

In the burner device according to any one of claims 1 to 3, hydrogen-rich unreacted exhaust gas discharged from the fuel cell is supplied to the flame hole as part or all of the fuel gas. The present invention may be applied to a reformer burner device attached to a reformer so as to heat the reforming catalyst by the combustion heat of the combustion chamber (claim 4). By doing so, even if it is necessary to perform the combustion operation in a wide capacity range as the burner device for the reformer, it is possible to accurately grasp the flame temperature change based on the flame temperature detected by the temperature detecting means, and The operation of the system can be controlled more accurately.

[0013]

As described above, according to the burner device of the first aspect, the temperature detecting means sets the flame port density of the specific area on the opposing burner plate to a coarser density than the other areas. As a result, the temperature detecting means is made less susceptible to the effect of cooling by the unburned gas in the unburned portion even if the combustion flame has a large capacity. It is possible to make it hard to be directly affected by the high temperature part. Thus, the conditions for detecting the flame temperature by the temperature detecting means can be made more uniform over a wide range of capabilities.

According to the burner device of the second aspect, the temperature detecting means makes the specific area on the opposing burner plate a non-formed area of the flame port so that the flame port does not exist. The temperature detection means is prevented from being affected by the cooling of the unburned gas due to the unburned gas even if the combustion flame has a small capacity. It is also possible to avoid direct receipt of the means. As a result, the conditions for detecting the flame temperature by the temperature detecting means can be more reliably made uniform over the wide range of capabilities than in the case of the first aspect.

According to the third aspect, in addition to the effect of equalizing the detection conditions by the temperature detecting means over a wide capability range in the first or second aspect, the durability of the material or the like forming the temperature detecting means is improved. The restriction based on the viewpoint can be alleviated, and the flame temperature can be reliably detected even when the combustion is performed by narrowing the capacity to a considerably small side.

According to a fourth aspect, the burner device according to any one of the first to third aspects is used as a burner device for a reformer for heating a reforming catalyst using unreacted exhaust gas discharged from a fuel cell as a fuel. By applying, even when it is necessary to perform combustion operation in a wide capacity range in the burner device for the reformer, it is possible to accurately grasp the flame temperature change based on the flame temperature detected by the temperature detecting means. Thus, the operation control of the fuel cell system can be performed more accurately.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A case where the present invention is applied to a burner device for a reformer of a fuel cell system as an embodiment of the present invention will be described below with reference to the drawings.

First, a fuel cell system using the burner device according to the present embodiment will be briefly described with reference to an example shown in FIG.

The fuel cell system shown in the figure uses a hydrogen-rich reformed gas generated by reforming a predetermined fuel in a reformer 200 as hydrogen required in a fuel cell 100 such as a polymer electrolyte fuel cell. On the other hand, the reformer 200
Burner device 300 for heating reforming catalyst 201
In the above, the unreacted exhaust gas discharged from the fuel cell 100 is used as part or all of the fuel.

That is, the fuel cell 100 includes a cathode (air electrode) 101, an anode (hydrogen electrode) 102, and an electrolyte 103.
Then, a hydrogen-rich reformed gas is supplied to each of the anodes 102. In the fuel cell 100, power is generated by an electrochemical reaction between oxygen in the air and hydrogen in the reformed gas based on an electrochemical principle opposite to that of water electrolysis. Then, water generated by this reaction and unreacted exhaust gas (unused reformed gas) are discharged.

The generation of the hydrogen-rich reformed gas in the reformer 200 is performed as follows. That is, the raw fuel gas (for example, city gas) is supplied to the reformer 200 through the raw fuel gas supply pipe 203 in which the first flow control valve 202 is interposed.
Will be introduced. Before the introduction, the sulfur content in the raw fuel gas is desulfurized by a desulfurizer (not shown).
Steam from a steam supply source is mixed into the raw fuel gas through a steam supply pipe 204. And reformer 2
00, the reforming catalyst 201 is
The raw fuel gas thus introduced is steam-reformed based on an endothermic reaction of the reforming catalyst 201 to generate a hydrogen-rich reformed gas. The generated reformed gas is supplied to the anode 102 of the fuel cell 100 after CO (carbon monoxide) in the reformed gas is denatured and removed by the CO processor 205.

On the other hand, in the burner device 300, combustion air is previously supplied to the unreacted exhaust gas alone or to a fuel gas in which the unreacted exhaust gas is mixed with the raw fuel gas (hereinafter, referred to as a city gas). The mixed gas after mixing is burned. That is, the unreacted exhaust gas supplied from the fuel cell 100 through the exhaust gas supply pipe 301,
The city gas which is branched from the raw fuel gas supply pipe 203 on the upstream side of the first flow control valve 202 and which is supplied through a branched raw fuel gas supply pipe 303 provided with a second flow control valve 302 on the way is joined. Fuel gas composed of only unreacted exhaust gas or both is introduced into the burner device 300 at 305. Then, air from the air supply pipe 304 is preliminarily mixed with the introduced fuel gas as described later, and a mixed gas in which the air is preliminarily mixed is burned (premixed combustion). By allowing the combustion exhaust gas generated by this combustion to pass through, for example, the inner and outer peripheries of the cylindrical reforming catalyst 201,
The reforming catalyst 201 is heated.

The amount of city gas supplied to the burner device 300 is changed and adjusted by adjusting the opening degree of the second flow control valve 302, whereby the mixing ratio of the city gas (0%) in the fuel gas is changed. Changes) are adjusted.

Next, FIG.
This will be described with reference to FIG.

The burner device 300 has a substantially cylindrical burner case 2 and a thick-walled circle having a plurality of flame holes 30, 30,. A plate-shaped burner plate 3, a bottomed cylindrical burner cover 4, a plurality of communication tubes 5, 5,..., Both disc-shaped first and second baffle plates 6, 7; Are provided as main components to realize premixed combustion and lean / burn combustion.

The burner case 2 is made of a material having a high thermal conductivity, such as aluminum, made of an upper tubular portion 21 and a mounting flange portion 22, an outer tubular portion 23 and an inner tubular portion 24, and a partition wall 25 for partitioning the upper and lower portions. It is formed integrally with a high heat conductive material such as copper or copper. Then, the mounting flange portion 22
Is attached to the reformer 200 together with the burner cover 4 described later, so that the burner device 300
It is fixed to 0.

The burner plate 3 is held inside the upper cylinder portion 21, and a combustion chamber 9 partitioned by the burner plate 3 and the upper cylinder portion 21 and communicating with the reformer 200 is formed. The burner cover 4 is tightly fitted on the outer peripheral surface of the upper cylindrical portion 21.

The upper and lower dimensions of the inner cylinder 24 are the outer cylinder 2
3, the first baffle plate 6 is fixed to the lower end opening of the outer cylinder portion 23, and the second baffle plate 7 is fixed to the lower end opening position of the inner cylinder portion 24. .
The branch pipe 8 is connected to the bottom wall 4 of the burner cover 4.
The first baffle plate 6 and the center aperture 71 of the second baffle plate 7 are fixed so as to extend upward from the center position of the first baffle plate 6 and the center hole 71 of the second baffle plate 7. Thereby, the first light mixing chamber 10a is formed as an annular space between the flow dividing pipe 8 and the outer cylindrical portion 23, and the second light mixing chamber 10b is formed as an annular space between the inner and outer cylindrical portions 23, 24. Have been. In the inner cylindrical portion 24, the dense mixing chamber 11 is defined by the upper part of the distribution pipe 8 and the partition wall portion 25.

An air preheating chamber 12 is defined by an annular space between the burner cover 4 and the outer cylindrical portion 23 and a space between the bottom wall portion 41 of the burner cover 4 and the first baffle plate 6. The air preheating chamber 12 preheats combustion air supplied from the air supply pipe 304 by heat transfer from the combustion chamber 9. A junction 305 of the exhaust gas supply pipe 301 and the branch supply pipe 303 is fixed to the bottom wall 41 of the burner cover 4 so as to communicate only with the branch pipe 8, and the fuel gas from the junction 305 is divided. It is supplied to a tube 8.

On the other hand, the upper part of the second light mixing chamber 10b
A plurality of communication pipes 5, 5, fixed at predetermined intervals in a circumferential direction;
Are connected to each other with a predetermined inner peripheral area of the flame holes 30, 30,.
, Are communicated with each other.

The plurality of flame ports 31, 31,... Opening on the burner plate 3 have a plurality of flame ports 32 collectively arranged in a circular area as shown in FIG. 8) It is formed continuously. The inner diameter of each of the communication pipes 5 is set to a size corresponding to the intermediate diameter of the outer diameter of each of the collective flame ports 32, and the communication pipes 5 are individually brought into close contact with each of the collective flame ports 32. ing. Accordingly, the light mixed gas is supplied from the second light mixing chamber 10b to each of the flame ports 31 only in the inner peripheral range of each of the collective flame ports 32 through each communication pipe 5. on the other hand,
Partition plate 1 fixed at the upper and lower intermediate position of each communication pipe 5
4 (see also FIG. 2), a plurality of ejection holes 141, 141,... Are formed at predetermined intervals so as to surround the communication pipes 5. The concentrated mixed gas supplied through the central hole 26 is supplied only to each of the flame ports 31 in the outer peripheral area of each of the collective flame ports 32.

In the burner device 300, for example, when the fuel cell system is started, only the city gas is burned as the fuel gas, and the unreacted exhaust gas discharged from the fuel cell 100 after the start is mixed with the city gas. The supply of city gas is stopped and only unreacted exhaust gas is burned as fuel gas.

The combustion operation is performed as follows. That is, when the air supplied to the air preheating chamber 12 and preheated passes through the central throttle passage 61 of the first baffle plate 6, the lower outlet port 8 of the diverter pipe 8 responds to the increased airflow.
The fuel gas is mixed from 1, 81,... To become a light mixed gas and flows into the first light mixing chamber 10a. When a part of the light mixed gas flows into the rich mixing chamber 11 from the center hole 71, fuel gas is further mixed in from the upper ejection holes 82, 82,. The gas is supplied to a large number of flame ports 31, 31,... In the outer peripheral area of each of the collective flame port sections 32, and burns as a rich flame on the upper surface of the burner plate 3. On the other hand, after the other portion of the light mixed gas in the first light mixing chamber 10a passes through the plurality of cut-and-raised passages 72 of the second baffle plate 7 and flows into the second light mixing chamber 10b as a swirling flow, It is supplied to a large number of flame ports 31, 31 in the inner peripheral area of each of the collective flame port sections 32, and is burned as a light flame on the upper surface of the burner plate 3.

In the above-described burner apparatus, the temperature detection means for detecting the flame temperature of the combustion flame is provided above one of the collective flame ports 32a among the collective flame ports 32, 32,... For example, a thermocouple 13 sealed in a sheath is provided to protrude into the combustion chamber 9.

The assembled flame outlet 3 below the thermocouple 13
2a, as shown in FIG. 4, a specific area 33a obtained by adding a small peripheral area to a projection area on the burner plate 3 when the thermocouple 13 is projected downward to the burner plate 3 does not form a flame port. The specific area 3
A large number of flame ports 31 are formed in an area 33b other than the area 3a. As shown in FIG. 5, the thermocouple 13 is located at a position relatively close to the upper surface of the burner plate 3 in the specific area 33a.

Thus, regardless of whether the combustion flame formed in each of the flame ports 31 of the collective flame port portion 32a has a large capacity or a small capacity, the thermocouple 13 has the combustion flame. The flame temperature can be detected under uniform detection conditions without being directly affected by the unburned portion or the high temperature portion of the active portion. For example, unlike the conventional case, the thermocouple 13 '(see FIG. 12) does not enter the unburned portion of the combustion flame at the time of the large capacity and is not affected by the cooling by the unburned gas. It is not affected by the high temperature caused by contact with the surroundings of the active portion of the device.

<Second Embodiment> FIG. 6 is a plan view of a burner device 300 according to a second embodiment. The second embodiment differs from the first embodiment only in the arrangement structure of a thermocouple 13 as a temperature detecting means, and other configurations are the same as those of the first embodiment shown in FIG.
It is the same as that of the embodiment. For this reason, the same components are denoted by the same reference numerals as in the first embodiment, and a detailed description thereof will be omitted.

As shown in FIGS. 7 and 8, a concave groove 34 is formed in a specific area 33a of the collective flame opening 32a where the thermocouples 13 are vertically opposed to each other.
The concave groove 34 opens upward (toward the combustion chamber 9) to open the thermocouple 1.
The thermocouple 13 is disposed along the lower surface of the burner plate 3 with its lower part fitted in the groove 34 and its upper part projected from the upper surface of the burner plate 3.

In the case of the second embodiment, the detection of the flame temperature in a wide range of performance can be performed under uniform detection conditions without being directly affected by the unburned portion of the combustion flame or the high temperature portion of the active portion. In addition to the effect of the first embodiment, the detection of the flame temperature is ensured even when the combustion flame is set to a considerably small capacity of not more than the diameter of the thermocouple 13. Will be able to do it. In addition, since the lower periphery of the thermocouple 13 is covered with the concave groove 34, restrictions on materials and the like required for maintaining the durability of the thermocouple 13 can be further relaxed.

<Other Embodiments> The present invention relates to the first embodiment.
The present invention is not limited to the second embodiment, and includes various other embodiments. That is, in the above-described first embodiment, the specific region 33a is a non-forming region having no flame port 31. However, the present invention is not limited to this, and the flame port 31 may be present. In this case, for example, as shown in FIG. 9, the flame port density of the flame port 31 formed in the specific area 33a may be set to be lower than that of the other area 33b. In this case, although the effect is inferior to that of the first embodiment, the direct influence from the unburned portion of the combustion flame at the time of large capacity or the high temperature portion of the active portion of the combustion flame at the time of small capacity is specified as above. Area 33a
In addition, it is possible to reduce the difficulty compared to the case where the flame port 31 is formed with the same flame density as the other region 33b. As a result, it is possible to detect the flame temperature under a condition approaching more uniform detection conditions.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a fuel cell system to which an embodiment of the present invention is applied.

FIG. 2 is an explanatory longitudinal sectional view showing the first embodiment.

FIG. 3 is a partially cutaway plan view of FIG. 2;

FIG. 4 is a partially enlarged explanatory view of FIG. 3;

FIG. 5 is an explanatory sectional view taken along line AA of FIG. 4;

FIG. 6 is a diagram corresponding to FIG. 3 of a second embodiment.

FIG. 7 is a partially enlarged explanatory view of FIG. 6;

FIG. 8 is an explanatory sectional view taken along line BB of FIG. 6;

FIG. 9 is a view corresponding to FIG. 4, showing another embodiment.

FIG. 10 is a partial sectional explanatory view showing an example of a conventional burner device.

FIG. 11 is an explanatory plan view of FIG. 10;

12A and 12B are explanatory diagrams showing a relationship between a conventional combustion flame and a thermocouple, wherein FIG. 12A shows a case where the combustion flame has a large capacity, and FIG. 12B shows a case where the combustion flame has a small capacity. Each case is shown.

[Explanation of symbols]

 3 Burner Plate 9 Combustion Chamber 13 Thermocouple (Temperature Detecting Means) 30 Flame Hole 31 Flame Port 33a Specific Region 33b Other Region 34 Depressed Groove (Concave) 100 Fuel Cell 200 Reformer 201 Reforming Catalyst 300 Burner Device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Akira Fujio 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Koji Kishio 93-93 Edocho, Chuo-ku, Kobe-shi, Hyogo Prefecture Within Noritz, Inc. 72) Inventor Takeshi Wakata 93 Edo-cho, Chuo-ku, Kobe-shi, Hyogo F-term in Noritz Co., Ltd. 3K005 AA06 AB04 AC02 AC05 CA06 EA02 EB02 3K017 AA03 AB01 AB08 AB09 AC02 AD14

Claims (4)

[Claims] 1. A burner having a burner plate having a large number of flame openings opening toward a combustion chamber, and burning a fuel gas ejected from each of the flame openings toward the combustion chamber to form a combustion flame in each of the flame openings. The apparatus further includes temperature detection means for projecting into the combustion chamber and detecting a flame temperature of a combustion flame formed in the flame port, and a specific region on the burner plate at least opposed to the temperature detection means is provided. A burner device characterized in that the burner port density of the burner port is set to be at least coarser than that of another region. 2. A burner, comprising: a burner plate having a large number of flame openings opening toward a combustion chamber, and burning a fuel gas ejected from each of the flame openings toward the combustion chamber to form a combustion flame in each of the flame openings. The apparatus further includes temperature detection means for projecting into the combustion chamber and detecting a flame temperature of a combustion flame formed in the flame port, and a specific region on the burner plate at least opposed to the temperature detection means is provided. A burner device wherein the flame outlet is a non-formed non-formed region. 3. The burner device according to claim 1, wherein a concave portion that opens to the combustion chamber side is formed in a specific area on the burner plate, and at least a part of the temperature detecting means is provided. A burner device disposed so as to be fitted into the recess. 4. The burner device according to claim 1, wherein hydrogen-rich unreacted exhaust gas discharged from the fuel cell as a part or all of the fuel gas is supplied to the flame hole. A burner device configured to be supplied and configured to be attached to a reformer for heating a reforming catalyst by combustion heat of a combustion chamber.