JP5415497B2 - Combustion device - Google Patents

Description

  In the present invention, a combustion plate is mounted on the upper surface of a box-shaped burner body that opens upward, and fuel is produced from a number of flame holes formed in a flame formation region inward from the outer edge of the combustion plate that serves as a fixing portion for the burner body. The present invention relates to a combustion apparatus including an all-primary combustion burner that ejects a premixed gas of gas and primary air and performs all-primary combustion.

  The temperature of the flame generated by the combustion of the premixed gas ejected from the combustion plate of this type of primary combustion burner is determined by the excess air ratio of the premixed gas (primary air amount / theoretical air amount necessary for combustion of the fuel gas). It becomes the highest at 1 and decreases as the excess air ratio exceeds 1 and increases. As the flame temperature decreases, the amount of nitrogen oxides in the combustion exhaust gas decreases, so it is desirable to make the excess air ratio of the premixed gas greater than 1. On the other hand, if the excess air ratio is excessively increased, the combustion speed of the premixed gas is lower than the ejection speed, and the flame is easily lifted. Therefore, a temperature sensor (for example, a thermocouple) is provided so as to protrude from the outside to the inside of the combustion plate so as to face the flame formation region of the combustion plate, and the premixed gas air is output from the output of this temperature sensor. The excess ratio of the premixed gas is set to a predetermined value larger than 1 by indirectly detecting the excess ratio and adjusting at least one of the fuel gas amount and the primary air amount supplied to the burner according to the output. Try to keep on.

  By the way, it is difficult to keep the amount of protrusion of the temperature sensor with respect to the combustion plate constant. Here, if the temperature sensor is arranged so as to be directly exposed to the flame, the area of the temperature sensor exposed to the flame (heat receiving area) varies due to variations in the protruding amount of the temperature sensor, and the output of the temperature sensor changes. . As a result, even if the excess air ratio is constant, the output of the temperature sensor changes due to variations in the protruding amount of the temperature sensor, and the detection accuracy of the excess air ratio deteriorates.

  In order to eliminate such a problem, there is conventionally known a flameless region of the combustion plate provided with a flameless hole portion that does not form a flamehole over a predetermined range including a portion located directly below the temperature sensor. (For example, refer to Patent Document 1). In this case, the temperature sensor is heated by the flame of the flame hole around the flameless hole, and the temperature sensor output of the temperature sensor due to variations in the protruding amount of the temperature sensor is different from that in which the temperature sensor is directly exposed to the flame. The change width becomes smaller.

  By the way, if the flame hole load (the amount of gas ejected in terms of the calorific value per unit area of the flame hole) increases, the flame easily lifts. And if a flame lift arises around a flameless hole part, the output of a temperature sensor will fall and the detection accuracy of an excess air ratio will deteriorate. Therefore, the direction parallel to the plate surface of the combustion plate orthogonal to the longitudinal direction of the temperature sensor is defined as the Y-axis direction, in each flame forming region located on one side and the other side of the flameless hole in the Y-axis direction, It is considered to provide a second flameless hole portion that does not form a flame hole, positioned outside the flame hole forming portion for heating the temperature sensor in which a plurality of flame holes adjacent to the flameless hole portion are formed, in the Y-axis direction. It is done. According to this, the premixed gas is returned to the second flameless hole portion, and a flame holding action is obtained.

  Here, the flame lift is generated starting from the outer end portion of the flame forming region having a relatively low temperature, and then proceeds inward of the flame forming region. Therefore, even if the second flameless hole is provided as described above, if the flame lift generated at the outer end in the Y-axis reaches the second flameless hole, the temperature sensor heating flame hole forming part The flame lift cannot be prevented, and the detection accuracy of the excess air ratio is deteriorated.

Japanese Utility Model Publication No. 63-54946

  This invention makes it the subject to provide the combustion apparatus which enabled it to prevent the deterioration of the detection accuracy of the excess air ratio by a flame lift in view of the above point.

  In order to solve the above-mentioned problems, the present invention has a combustion plate mounted on the upper surface of a box-shaped burner body that opens upward, and is located in a flame formation region inward from the outer edge of the combustion plate that serves as a fixing portion for the burner body. A primary combustion burner that ejects a premixed gas of fuel gas and primary air from a number of formed flame holes to perform primary combustion, and an outer edge of the combustion plate so as to face the flame formation region of the combustion plate A combustion device for adjusting at least one of the amount of fuel gas and the amount of primary air supplied to the burner according to the output of the temperature sensor, and a flame of the combustion plate In the formation region where a flameless hole portion that does not form a flame hole is provided over a predetermined range including a portion located immediately below the temperature sensor, the direction parallel to the plate surface of the combustion plate perpendicular to the longitudinal direction of the temperature sensor As the Y-axis direction, The Y axis of the temperature sensor heating flame hole forming part in which a plurality of flame holes adjacent to the flameless hole part are formed in each flame forming region located on one side and the other side in the Y axis direction of the flame hole part A second flameless hole portion that does not form a flame hole is provided on the outer side in the direction, and faces the outer flame hole forming portion that is located on the outer side in the Y-axis direction from the second flameless hole portion. An obstacle is provided in which gas flows ejected from at least some of the plurality of flame holes formed in the flame hole forming portion collide with each other.

  Here, in the obstacle arrangement part, the jet gas flow collides with the obstacle to prevent the flame lift. And in this invention, since an obstruction is arrange | positioned on the outer flame hole formation part outside a Y-axis direction rather than a 2nd flameless hole part, the flame from a Y-axis direction outer end part to a Y-axis direction inward It is possible to prevent the flame lift from reaching the second flameless hole by stopping the progress of the lift at the obstacle arrangement portion. Therefore, in combination with the flame holding action due to the reflux of the premixed gas to the second flameless hole, it is possible to effectively prevent the flame lift at the temperature sensor heating flame hole forming part. As a result, it is possible to prevent the detection accuracy of the excess air ratio from deteriorating due to a decrease in the temperature sensor output due to the flame lift.

  It is also conceivable to place an obstacle on the temperature sensor heating flame hole forming portion. However, in this case, the flame spreads under the obstacle, and the spread state changes according to the flame hole load, and the heating amount of the temperature sensor also changes, and the detection accuracy of the excess air ratio deteriorates. On the other hand, in the present invention, since no obstacle is arranged on the temperature sensor heating flame hole forming portion, the above-mentioned problems do not occur.

  Incidentally, the burner is generally provided with an ignition electrode and a flame rod for detecting ignition and misfire in addition to the temperature sensor. Here, the ignition electrode is disposed so as to face the outer flame hole forming part of the flame forming region on one side of the flameless hole part in the Y axis direction, and the frame rod is further arranged in the Y axis direction of the flameless hole part. If the obstacle is formed by the ignition electrode and the frame rod, the obstacle is formed by facing the outer flame hole forming portion of the flame forming region on the other side, and the cost can be reduced by reducing the number of parts. It is.

  In the present invention, the longitudinal direction of the temperature sensor is defined as the X-axis direction, and the direction opposite to the protruding direction of the temperature sensor is defined as the outward direction of the X-axis. It is desirable to provide a flame-holding flame hole forming portion in which a plurality of decelerating flame holes are formed at a lower speed of the premixed gas ejection than a general flame hole including a flame hole formed in the heating flame hole forming portion. According to this, generation | occurrence | production of the flame lift in the X-axis direction outer side edge part of a flame formation area | region is prevented, and the flame lift in the temperature sensor heating flame hole formation part can be prevented more reliably.

The perspective view of the combustion apparatus of embodiment of this invention. The cutaway side view of the combustion apparatus of an embodiment. Sectional drawing cut | disconnected by the III-III line | wire of FIG. The expanded cutting top view cut | disconnected by the IV-IV line of FIG. The graph which shows a test result.

  1 to 3, reference numeral 1 denotes an all primary combustion burner. The burner 1 is configured by mounting a ceramic combustion plate 3 on the upper surface of a burner body 2.

  The burner body 2 is a die-cast product, and is formed in a box shape that opens upward. A flange portion 21 is provided on the upper surface of the burner body 2 to surround the opening covered with the combustion plate 3. And the outer edge part of the combustion plate 3 is being fixed on the flange part 21 in the state which sandwiched the packing 211 between the flange parts 21. As shown in FIG. The combustion plate 3 is provided with a flame forming region 31 (see FIG. 4) inward from an outer edge portion that is a fixed portion with respect to the burner body 2, and a plurality of flame holes 3 a are formed in the flame forming region 31. Yes.

  A distribution chamber 22 facing the lower surface of the combustion plate 3 and a mixing chamber 23 below the bottom wall 221 of the distribution chamber 22 are provided in the burner body 2. An air supply chamber 24 surrounded by a case 241 attached to the lower surface of the burner body 2 is provided below the mixing chamber 23. A fan 242 is connected to one end of the air supply chamber 24 in the horizontal direction.

  At the rear of the bottom wall 221 of the distribution chamber 22, an opening 222 that connects the distribution chamber 22 and the mixing chamber 23 is formed. The distribution chamber 22 is partitioned into two upper and lower spaces by a partition plate 223. The premixed gas flowing into the lower space of the distribution chamber 22 from the mixing chamber 23 through the opening 222 is formed in the partition plate 223 and the combustion plate 3 through the upper space of the distribution chamber 22. To be guided to. The premixed gas guided to the combustion plate 3 is ejected from the flame holes 3a and undergoes primary combustion.

  The front surface of the mixing chamber 23 is closed by a front wall 231 integrated with the burner body 2. A plurality of nozzle holes 232 are formed in the front wall 231 at intervals in the horizontal direction. A gas manifold 25 is attached to the front surface of the front wall 231 via a partition plate 251 that defines a nozzle passage 233 communicating with the nozzle holes 232 with the front wall 231. An opening (not shown) for communicating the gas passage 252 and the nozzle passage 233 in the gas manifold 25 is formed in the partition plate 251, and an electromagnetic valve 253 for opening and closing the opening is attached to the gas manifold 25. Yes. When the electromagnetic valve 253 is opened, the fuel gas is supplied to the nozzle passage 233 and the fuel gas is injected from each nozzle hole 232.

  The bottom surface of the mixing chamber 23 is closed by a bottom plate 234 separate from the burner body 2. A wall plate 235 is formed at the front end of the bottom plate 234 so as to face the front wall 231 with a ventilation space and to which fuel gas ejected from each nozzle hole 232 collides. In addition, an air introduction port 236 communicating with the air supply chamber 24 is opened at a portion facing the ventilation space on the bottom surface of the mixing chamber 23. Then, air blown from the fan 242 to the air supply chamber 24 is supplied as primary air to the ventilation space via the air inlet 236, and the fuel gas and the primary air that collide with the wall plate 235 and diffuse are mixed into the mixing chamber 23. So that a premixed gas is generated.

  In this embodiment, the distribution chamber 22 and the mixing chamber 23 are divided into a relatively large # 1 distribution chamber 22 and mixing chamber 23 by a partition wall 26 integral with the burner body 2, and relatively small # 2 and # 3. The distribution chamber 22 and the mixing chamber 23 are divided into three, and a structure is formed by combining substantially three burners. The gas manifold 25 is provided with three solenoid valves 253 so that fuel gas can be individually supplied to the three-divided mixing chambers 23 of # 1 to # 3. The combustion plate 3 is divided into a # 1 combustion plate 3 covering a relatively large # 1 distribution chamber 22 and a # 2 combustion plate 3 covering a relatively small # 2 and # 3 distribution chambers 22 and 22. Divided into two. The flame forming region 31 of the # 2 combustion plate 3 is divided into a region located on the # 2 distribution chamber 22 and a region located on the # 3 distribution chamber 22.

  Further, the combustion apparatus of the present embodiment includes a combustion housing 4 that surrounds the combustion space above the combustion plate 3. The combustion housing 4 is composed of an upper housing 42 that houses a heat exchanger 41 for hot water supply or heating that is an object to be heated, and a lower housing 43 that is connected to the lower end of the upper housing 42. An inner bending flange 431 is formed at the lower end of the lower housing 43, and the inner bending flange 431 is fastened to the flange portion 21 with the packing 211 sandwiched between the flange portion 21 of the burner body 2. Yes. Further, an upright plate portion 432 that rises from the inner edge of the inner bending flange 431 is provided, and an engaging plate portion 433 that bends inward and engages with the upper surface of the outer edge portion of the combustion plate 3 is bent at the upper end of the upright plate portion 432. doing. When the inner bending flange 431 is fastened to the flange portion 21, the combustion plate 3 is pressed downward and fixed by the engagement plate portion 433.

  A heat shield plate 44 is disposed on the inner side of the rear plate portion of the lower housing 43 and the inner side plate portions on both sides in the lateral direction. An inner bending flange 441 is formed at the lower end of the heat shield plate 44, and the inner bending flange 441 is fastened to the flange portion 21 in a state where the inner bending flange 441 is overlapped with the inner bending flange 431 of the lower housing 43.

  In addition, a viewing window 45 fitted with glass is provided on the front plate portion of the lower housing 43, and a thermocouple 5, an ignition electrode 6, and a frame rod 7 as temperature sensors are mounted. As shown in FIGS. 2 to 4, the thermocouple 5 is located on the outer side of the outer edge of the combustion plate 3 so as to face the flame formation region 31 of the # 2 combustion plate 3 located on the # 2 distribution chamber 22. Projecting inward. In addition, a through hole 434 through which the thermocouple 5 is inserted as shown in FIG. 2 is formed at the upper end of the portion of the upright plate portion 432 that coincides with the location of the thermocouple 5 without bending the engagement plate portion 433. Yes.

  The longitudinal direction of the thermocouple 5 is the X-axis direction, the protruding direction of the thermocouple 5 and the opposite direction are the X-axis direction inward and X-axis direction outward, and the plate surface of the combustion plate 3 orthogonal to the X-axis direction, respectively. With the parallel direction as the Y-axis direction, the ignition electrode 6 is disposed on one side of the thermocouple 5 in the Y-axis direction, and the frame rod 7 is disposed on the other side of the thermocouple 5 in the Y-axis direction. Further, a ground electrode plate 46 is erected on the portion of the inwardly bent flange 431 that matches the arrangement portion of the thermocouple 5, the ignition electrode 6, and the frame rod 7. At the upper end of the electrode plate 46, an electrode portion 461 bent inward in the X-axis direction so as to face the ignition electrode 6, and an electrode portion bent inward in the X-axis direction so as to face the frame rod 7 462 is composed. Then, ignition is performed by spark discharge between the ignition electrode 6 and the electrode portion 461, and ignition and misfire detection are performed based on the presence or absence of a flame current flowing between the frame rod 7 and the electrode portion 462. ing.

  By the way, the temperature of the flame generated by the combustion of the premixed gas ejected from the flame hole 3a of the combustion plate 3 decreases as the excess air ratio of the premixed gas increases from one. Therefore, the excess air ratio can be indirectly detected from the output of the thermocouple 5. Therefore, at least one of the amount of fuel gas supplied to the burner 1 and the amount of primary air is adjusted according to the output of the thermocouple 5, and the excess air ratio is maintained at a predetermined set value (for example, 1.3) greater than 1. Is controlled to be.

  In addition, it is difficult to manage the protrusion amount of the thermocouple 5 uniformly. Therefore, if the output of the thermocouple 5 varies due to variations in the protrusion amount of the thermocouple 5, the detection accuracy of the excess air ratio deteriorates and the excess air ratio cannot be controlled appropriately.

  Therefore, in the present embodiment, the flame forming region 31 of the # 2 combustion plate 3 is provided with a flameless hole portion 32 that does not form the flame hole 3a over a predetermined range including a portion located immediately below the thermocouple 5. ing. According to this, the thermocouple 5 is heated by the flame of the flame hole 3a around the flameless hole portion 32, and the amount of protrusion of the thermocouple 5 is larger than that of directly exposing the thermocouple 5 to the flame. The change width of the output due to the variation is reduced. Therefore, even if the amount of protrusion of the thermocouple 5 varies, the detection accuracy of the excess air ratio does not deteriorate so much, and the excess air ratio can be controlled appropriately.

  By the way, when the flame hole load is increased, the flame is easily lifted. When a flame lift is generated in the flame hole 3a adjacent to the flameless hole 32, the output of the thermocouple 5 is lowered even if the excess air ratio is constant, and the detection accuracy of the excess air ratio is deteriorated.

  Therefore, in the present embodiment, a plurality of flame holes 3a adjacent to the flameless hole 32 are formed in each flame formation region 31 located on one side and the other side of the flameless hole 32 in the Y-axis direction. A second flameless hole 34 that does not form a flame hole is provided outside the temperature sensor heating flame hole forming part 33 in the Y-axis direction. According to this, a part of the premixed gas ejected from the temperature sensor heating flame hole forming part 33 and a pre-ejection gas from the outer flame hole forming part 35 located outside the second flameless hole part 34 in the Y-axis direction. A part of the mixed gas is refluxed to the second flameless hole 34 to obtain a flame holding action. As a result, it is possible to suppress the occurrence of a flame lift in the temperature sensor heating flame hole forming portion 33 and prevent the detection accuracy of the excess air ratio from being deteriorated due to the flame lift.

  However, the flame lift generally occurs from the outer end portion of the flame forming region 31 having a relatively low temperature, and then proceeds inward of the flame forming region 31. When the flame lift generated at the outer end of the flame forming region 31 in the Y-axis direction advances inward in the Y-axis direction and reaches the second flameless hole 34, the temperature sensor heating flame hole forming part 33 Can no longer prevent the flame lift.

  Therefore, in the present embodiment, the ignition electrode 6 is disposed so as to face the outer flame hole forming portion 35 of the flame forming region 31 on one side of the flameless hole portion 32 in the Y-axis direction, and the frame rod 7 is It arrange | positions so that it may face on the outer flame hole formation part 35 of the flame formation area | region 31 of the Y-axis direction other side of the flame hole part 32. FIG. Specifically, the ignition electrode 6 is disposed so as to face the upper side of a part of the flame holes 3 a formed in the corresponding outer flame hole forming portion 35, and the frame rod 7 is arranged in the corresponding outer flame hole forming portion 35. It arrange | positions so that it may oppose above the some flame holes 3a formed. The distance between the tip of the ignition electrode 6 and the upper surface of the combustion plate 3 is set to about 5 mm, and the distance between the frame rod 7 and the upper surface of the combustion plate 3 is also set to about 5 mm.

  According to this, the premixed gas ejected from the lower flame hole 3a collides with the ignition electrode 6 and the frame rod 7, and the flame lift in this flame hole 3a is prevented. For this reason, the flame lift generated at the outer end of the flame forming region 31 in the Y-axis direction is prevented from proceeding inward in the Y-axis direction by the arrangement portion of the ignition electrode 6 and the frame rod 7, and the flame lift becomes the second flameless. Reaching the hole 34 can be prevented. Therefore, in combination with the flame holding action by the reflux of the premixed gas to the second flameless hole 34, it is possible to effectively prevent the flame lift in the temperature sensor heating flame hole forming part 33.

  Further, in the present embodiment, a general flame hole including a flame hole 3 a formed in the temperature sensor heating flame hole forming part 33 or the outer flame hole forming part 35 at the outer end of the flame forming region 31 in the X-axis direction. A flame-holding flame hole forming portion 36 is provided in which a plurality of decelerating flame holes 3b whose premixed gas ejection speed is slower than 3a are formed. According to this, the flame holding action by the deceleration flame hole 3b prevents the flame holding hole forming portion 36, that is, the occurrence of the flame lift at the outer end of the flame forming region 31 in the X-axis direction. Flame lift at the heating flame hole forming portion 33 can be more reliably prevented.

  In this embodiment, the deceleration flame hole 3b is formed to have a smaller diameter than that of the general flame hole 3a so that the ejection speed of the premixed gas is slow. However, the deceleration flame hole 3b is replaced with the general flame hole 3a. It is also possible to form the same diameter. That is, the portion of the partition plate 223 located immediately below the flame holding flame hole forming portion 36 is brought closer to the lower surface of the combustion plate 3 to increase the airflow resistance between the flame holding flame hole forming portion 36 and the partition plate 223. By doing so, even if the deceleration flame hole 3b is formed to have the same diameter as the general flame hole 3a, it is possible to obtain a flame holding action by slowing the ejection speed of the premixed gas from the deceleration flame hole 3b.

In order to confirm the above effect, the combustion apparatus (invention product) of the present embodiment and the comparative product from which the ignition electrode 6 and the frame rod 7 were removed were used, and the excess air ratio was set at a flame hole load of 9 W / mm ^2. A test was conducted to measure the output of the thermocouple 5 while changing the above. In both the invention and the comparative product, the diameter of the thermocouple 5 is set to 3.2 mm, and the width of the flameless hole 32 in the Y-axis direction is set to 5.5 mm. The line a in FIG. 5 shows the result of the invention, and the line b shows the result of the comparative product. As is clear from FIG. 5, in the comparative product, the output of the thermocouple 5 rapidly decreases when the excess air ratio becomes 1.45 or more. This is because a flame lift occurred in the temperature sensor heating flame hole forming portion 33. On the other hand, in the invention product, the output of the thermocouple 5 decreases almost linearly until the excess air ratio decreases to 1.5. From this, it can be seen that by causing the ignition electrode 6 and the frame rod 7 to face the outer flame hole forming portion 35, the occurrence of flame lift in the temperature sensor heating flame hole forming portion 33 can be prevented.

  In the comparative product, even when the excess air ratio is in the range of 1.2 to 1.4, a flame lift occurs in the outer flame hole forming portion 35, and the flame of the temperature sensor heating flame hole forming portion 33 is lifted by the influence. It makes me feel. Therefore, in the range where the excess air ratio is 1.2 to 1.4, the thermocouple output is lower in the comparative product than in the inventive product.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to this. For example, in the above-described embodiment, the ignition electrode 6 and the frame rod 7 are used as obstacles to which the gas flow ejected from the flame hole 3a formed in the outer flame hole forming portion 35 collides. It is also possible to face a plate material and to form an obstacle with this plate material. However, the above embodiment in which the ignition electrode 6 and the frame rod 7 originally attached to the burner 1 constitute an obstacle is more advantageous because the number of parts can be reduced and the cost can be reduced.

  Moreover, in the said embodiment, although the thermocouple 5 is used as a temperature sensor, you may use the rod-shaped temperature sensor which incorporates the thermistor in the front-end | tip part. Furthermore, in the present invention, the combustion plate 3 is mounted on the upper surface of the burner body 2, but the vertical direction does not define the direction when the combustion device is used, and the posture is reversed upside down, that is, the combustion plate 3 Combustion devices that are used in a posture in which is directed downward are also included in the combustion device of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... All primary combustion type burner, 2 ... Burner main body, 3 ... Combustion plate, 3a ... Flame hole, 3b ... Deceleration flame hole, 31 ... Flame formation area, 32 ... Flameless hole part, 33 ... Flame hole for temperature sensor heating Forming part 34 ... second flameless hole part 35 ... outside flame hole forming part 36 ... flame holding hole forming part 5 ... thermocouple (temperature sensor) 6 ... ignition electrode (obstacle) 7 ... frame rod (obstacle).

Claims (4)

A combustion plate is mounted on the upper surface of a box-shaped burner body that opens upward, and fuel gas and primary air are emitted from a large number of flame holes formed in the flame formation region inside the outer edge of the combustion plate that serves as a fixed portion for the burner body. An all-primary combustion burner that injects a premixed gas with all primary combustion, and a temperature sensor that protrudes outward from the outer edge of the combustion plate to face the flame formation region of the combustion plate. A combustion device that adjusts at least one of the amount of fuel gas and the amount of primary air supplied to the burner according to the output of the temperature sensor,
In the flame forming region of the combustion plate, in which a flameless hole portion that does not form a flame hole is provided over a predetermined range including a portion located immediately below the temperature sensor,
The flame parallel to the plate surface of the combustion plate orthogonal to the longitudinal direction of the temperature sensor is defined as the Y-axis direction, and the flame-free region is located in each flame forming region located on one side and the other side of the flameless hole. A second flameless hole portion that does not form a flame hole is provided on the outside in the Y-axis direction of the temperature sensor heating flame hole forming portion in which a plurality of flame holes adjacent to the hole portion are formed,
A gas flow ejected from at least a part of the plurality of flame holes formed in the outer flame hole forming portion collides with the outer flame hole forming portion positioned on the outer side in the Y-axis direction from the second flameless hole portion. A combustion apparatus comprising an obstacle.   2. An ignition electrode facing the outer flame hole forming part of a flame forming region on one side in the Y-axis direction of the flameless hole part, wherein the obstacle is constituted by the ignition electrode. The combustion apparatus as described.   3. A frame rod facing the outer flame hole forming part of the flame forming region on the other side in the Y-axis direction of the flameless hole part, wherein the obstacle is constituted by the frame rod. The combustion apparatus as described. The temperature sensor heating flame hole is formed at the X-axis direction outer end of the flame forming region, with the longitudinal direction of the temperature sensor being the X-axis direction and the direction opposite to the protruding direction of the temperature sensor being the X-axis direction outward. The flame-holding flame hole forming portion in which a plurality of decelerating flame holes having a lower ejection speed of the premixed gas than a general flame hole including a flame hole to be formed in the forming portion is provided. 4. The combustion apparatus according to any one of 3 above.

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