JP2016090071A - Combustion apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustion apparatus such that a plurality of identical gas burners 6 which each have a flame hole part at an upper end part and are long in a front-rear direction are arranged in a lateral direction, a dumper 69 covers a gas introduction port 65a at an upstream end of a mixing pipe part 65 of each gas burner 6 and has an air hole 69a for primary air limitation overlapping the gas introduction port and smaller than the gas introduction port formed, and combustion noise can be reduced while combustion defects such as a back fire and a flame lift are suppressed.SOLUTION: Some gas burners 6 are made different in position relation of a center position O2 of an air hole 69a to a center position O1 of a gas introduction port 65a from other gas burners 6. For example, a #1 air hole 69a having a center position O2 above the center position O1 of the gas introduction port 65a and a #2 air hole 69a having a center position O2 below the center position O1 of the gas introduction hole 65a are arranged alternately.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a combustion apparatus used in a water heater or the like in which a plurality of gas burners having a longitudinal portion in the front-rear direction and having a flame opening at the upper end are arranged in parallel in the lateral direction.

  In this type of combustion apparatus, combustion vibration is likely to occur in each gas burner during high-load combustion. And the combustion vibration of the several gas burner of a combustion apparatus synchronizes, and a combustion noise becomes large.

  Therefore, conventionally, the nozzle diameter of the gas nozzle arranged facing the gas inlet at the upstream end of the mixing pipe portion of the gas burner or the size of the primary air restricting vent hole formed in the damper covering the gas inlet is made uniform. A gas burner in which the air-fuel ratio of the air-fuel mixture supplied to the gas burner is made different from that in other gas burners is known (for example, see Patent Document 1). ). According to this, a difference occurs between the frequency of combustion vibration in some gas burners and the frequency of combustion vibration in other burners due to the difference in the air-fuel ratio of the air-fuel mixture, and combustion occurs due to mutual interference due to the frequency difference. Noise is suppressed.

  However, when gas burners having different air-fuel ratios of the air-fuel mixture are mixed, there is a possibility that some of the gas burners generate red heat or flashback during low load combustion, or flame lift occurs during high load combustion.

JP-A-10-288315

  In view of the above points, an object of the present invention is to provide a combustion apparatus capable of reducing combustion noise while suppressing poor combustion such as red heat, flashback, and flame lift.

  In order to solve the above-mentioned problems, the present invention is a combustion apparatus in which a plurality of gas burners having the same length in the front-rear direction and having a flame opening at the upper end are arranged in parallel in the transverse direction, upstream of the mixing tube portion of each gas burner. In the case where a damper for covering the gas inlet at the end is provided and the damper has a primary air restriction vent hole smaller than the gas inlet overlapping the gas inlet, the central position of the gas inlet at the center of the vent The positional relationship with respect to is different from other gas burners in some gas burners.

  Here, if the distribution in the front-rear direction (air-fuel ratio distribution) of the air-fuel ratio of the air-fuel mixture ejected from the flame outlet of the gas burner is the same for all the gas burners, the frequency of combustion vibration generated at each location in the front-rear direction of each gas burner Coincides with the frequency of combustion vibration generated at the same position in the front-rear direction of the other gas burners, and the combustion noise increases. On the other hand, according to the present invention, the positional relationship of the central position of the vent hole with respect to the central position of the gas inlet is made different from that of the other gas burners by some gas burners, thereby The air-fuel ratio distribution of the air-fuel mixture can be made different from that of other gas burners. Then, due to the difference in air-fuel ratio distribution of the air-fuel mixture ejected from the flame outlet of the gas burner, the frequency of combustion vibration generated at each position in the front-rear direction of some gas burners and the same position in the front-rear direction of other gas burners are generated. A difference is produced between the frequency of the combustion vibrations, and the combustion noise can be reduced by the mutual interference action due to this frequency difference. Furthermore, the air-fuel ratio of the entire air-fuel mixture supplied to each gas burner is the same for all gas burners, unlike the case where some gas burners differ in the size of the vent so as to produce a difference in the primary air amount. . Therefore, unlike the conventional example in which gas burners having different air-fuel ratios of the air-fuel mixture are mixed, combustion defects such as red heat, flashback and flame lift can be suppressed.

  In the present invention, it is desirable that the positional relationship between the central position of the vent hole and the central position of the gas inlet is different between each gas burner and the gas burner adjacent thereto. According to this, there is a difference between the frequency of combustion vibration generated at each position in the front-rear direction of each gas burner and the frequency of combustion vibration generated at the same position in the front-rear direction of the gas burner adjacent thereto. Therefore, the mutual interference action due to the frequency difference can be obtained efficiently, and the combustion noise can be reduced more effectively.

The perspective view of the combustion apparatus of embodiment of this invention. The cutaway side view of the combustion apparatus of an embodiment. The perspective view of the gas burner provided in the combustion apparatus of embodiment. The perspective view of the decomposition | disassembly state of the gas burner of FIG. Sectional drawing cut | disconnected by the VV line | wire of FIG. (A) Front view of principal part of damper used in combustion apparatus of embodiment, (b) VIb-VIb line sectional view of FIG. 6 (a), (c) VIc-VIc line sectional view of FIG. 6 (a).

  With reference to FIGS. 1 and 2, the combustion apparatus of the embodiment of the present invention includes a combustion housing 1. The upper surface of the combustion casing 1 is open, and an object to be heated such as a hot water supply heat exchanger (not shown) is installed on the combustion casing 1. In the combustion housing 1, a partition plate 4 that partitions the space in the combustion housing 1 into a combustion chamber 2 and an air supply chamber 3 below the combustion chamber 2 is provided. A combustion fan 5 is connected to the bottom surface of the air supply chamber 3 via a duct 5 a, and air is supplied from the combustion fan 5 to the air supply chamber 3. A large number of distribution holes 4a are formed in the partition plate 4 so that air supplied to the air supply chamber 3 is supplied as secondary air to the combustion chamber 2 through these distribution holes 4a.

  In the combustion chamber 2, a plurality of gas burners 6 elongated in the front-rear direction are arranged in parallel in the lateral direction. A rising portion 41 is bent at the front edge of the partition plate 4, and a manifold 7 is mounted on the front side of the rising portion 41 so as to close the lower front surface of the combustion housing 1. The manifold 7 is provided with gas nozzles 71 and 72 facing gas introduction ports 65a and 67a at upstream ends of mixing pipe portions 65 and 67, which will be described later, of the respective gas burners 6. Further, a damper 69 that covers the gas inlets 65a and 67a of each gas burner 6 is provided on the front surface of the rising portion 41, and the gas inlets 65a and 67a that overlap the gas inlets 65a and 67a of each gas burner 6 are provided in the damper 69. Smaller primary air restricting vent holes 69a and 69b are formed. The fuel gas injected from the nozzle holes 71a and 72a of the gas nozzles 71 and 72 is supplied to the gas introduction ports 65a and 67a via the vent holes 69a and 69b, and rises from the air supply chamber 3 to the rising portion 41. The primary air is supplied to the gas inlets 65a and 67a through the air gaps defined between the manifold 7 and the air holes 69a and 69b.

  As shown in FIGS. 3 and 4, the gas burner 6 includes a burner body 61 and a burner cap 62 that covers the upper part of the burner body 61. At the upper end portion of the burner body 61, a flame mouth portion 63 that is elongated in the front-rear direction and opens upward is formed. Further, sleeve burner portions 64 located on both sides of the flame port portion 63 are formed by the burner cap 62. Then, a light mixture whose fuel concentration is leaner than the stoichiometric air-fuel ratio is ejected from the flame port 63, and a rich mixture whose fuel concentration is higher than the stoichiometric air-fuel ratio is ejected from the sleeve flame port 64, so-called concentration combustion is performed. I am doing so.

  As shown in FIG. 5, the burner body 61 is composed of a pair of side plates 61a and 61a facing each other in the lateral direction. The both side plates 61 a and 61 a are formed by bending one plate into a palmar state at a folding line that becomes the lower edge of the burner body 61. Then, by pressing each side plate 61 a, the upper end flame opening 63, the lower mixing pipe section 65, and the distribution chamber section that guides the air-fuel mixture from the mixing pipe section 65 to the flame opening 63. 66 is formed. The mixing tube portion 65 extends rearward from the upstream gas introduction port 65a located at the lower front edge of the burner body 61, and the distribution chamber portion 66 extends upward and backward from the rear end portion of the mixing tube portion 65. It is extended. In the upper part of the distribution chamber portion 66, a narrowed portion 66a having a narrower width is formed. The lateral width of the narrowed portion 66a gradually increases from the portion located directly above the connection portion between the mixing tube portion 65 and the distribution chamber portion 66 toward the front. Thereby, the front-rear direction flow rate distribution of the air-fuel mixture flowing into the flame port 63 is equalized. In addition, a mixing tube portion 67 for sleeve fire is formed at the front portion of the burner body 61 so as to be positioned between the mixing tube portion 65 and the distribution chamber portion 66. The mixing pipe portion 67 terminates slightly rearward from the gas introduction port 67a located at the front edge of the burner body 61, and a vent hole 67b is formed on the side surface of the rear end portion.

  The burner cap 62 has a pair of side plates 62a, 62a that covers the outside of the pair of side plates 61a, 61a of the burner body 61, and a plurality of bridge portions 62b that connect the side plates 62a, 62a at their upper edges. doing. Then, between the side plate 61a of the burner body 61 and the side plate 62a of the burner cap 62, the sleeve flame port portion 64 at the upper end and the mixing tube portion 67 for the sleeve fire are disposed outside the burner body 61 through the vent holes 67b. A passage for guiding the air-fuel mixture flowing out to the sleeve flame opening 64 is defined. Further, at a plurality of front and rear portions of the side plate 62a of the burner cap 62, concave portions 62c are formed that abut the outer surface of the side plate 61a of the burner body 61 and divide the sleeve flame opening 64 in the front-rear direction.

  In addition, a rectifying member 68 having a plurality of rectifying plates 68a arranged side by side is mounted in the flame opening 63. In the rectifying member 68, the rectifying plates 68 a are brought into contact with a plurality of front and rear portions that match the bridge portion 62 b of the burner cap 62, and the flame opening passage defined between the rectifying plates 68 a is formed in the front-rear direction. A contact portion 68b to be divided is formed. Further, a narrowed portion 63a is formed in the flame port portion 63 of the burner body 61 so as to be sandwiched between the rectifying members 68 from both sides in the lateral direction, at an intermediate portion in the vertical direction. As a result, a blind gap 63b is formed between the portion of the side plate 61a on the upper side of the constricted portion 63a and the outer rectifying plate 68a so that no air-fuel mixture is ejected, and the air-fuel mixture ejected from the flame opening 63 is above the blind gap 63b. In order to obtain a flame-holding effect.

  By the way, if the air-fuel ratio distribution (air-fuel ratio distribution) in the front-rear direction of the air-fuel ratio ejected from the flame outlet 63 of the gas burner 6 is the same in all the gas burners 6, combustion occurs at each position in the front-rear direction of each gas burner 6. The frequency of vibration coincides with the frequency of combustion vibration generated at the same position in the front-rear direction of the other gas burners 6, and the combustion noise increases.

  Therefore, in this embodiment, the positional relationship of the central position O2 of the vent hole 69a with respect to the central position O1 of the gas introduction port 65a is made different in some gas burners 6 from other gas burners 6. More specifically, referring to FIG. 6, from the # 1 vent hole 69a whose center position O2 is located above the center position O1 of the gas inlet 65a and the center position O1 of the gas inlet 65a. Also, the # 2 vent holes 69a with the center position O2 positioned below are alternately arranged. Since the input to the sleeve flame port 64 is much smaller than that of the flame port 63 and the combustion at the sleeve flame port 64 does not cause noise, the sleeve at the center of the sleeve flame hole 69b. The positional relationship with respect to the center position of the fire gas inlet 67a is the same in all the gas burners 6.

  When the positional relationship between the central position O2 of the vent hole 69a and the central position O1 of the gas inlet 65a is changed, the air-fuel ratio distribution of the air-fuel mixture ejected from the flame port portion 63 of the gas burner 6 changes, for example, the center of the vent hole 69a. If the position O2 is shifted downward from the center position O1 of the gas inlet 65a, the air concentration at the rear part of the burner increases. Then, by making the positional relationship of the central position O2 of the vent hole 69a with respect to the central position O1 of the gas introduction port 65a different from that of the other gas burners 6 by a part of the gas burners 6, it is ejected from the flame port 63 of the part of the gas burners 6. The air-fuel ratio distribution of the air-fuel mixture can be made different from that of the other gas burners 6. Then, due to the air-fuel ratio distribution difference of the air-fuel mixture ejected from the flame opening 63 of the gas burner 6, the frequency of the combustion vibration generated at each position in the front-rear direction of some gas burners 6 is the same as the front-rear direction of other gas burners 6. A difference is produced between the frequencies of the combustion vibrations generated at the locations, and the combustion noise can be reduced by the mutual interference effect due to the frequency difference. Further, unlike the case where some of the gas burners 6 are different in size of the air holes 69a from the other gas burners 6 so as to cause a difference in the primary air amount, the air-fuel ratio of the entire mixture supplied to each gas burner 6 is Unlike the conventional example in which the gas burners 6 are mixed and gas burners having different air-fuel ratios of the air-fuel mixture are mixed, combustion defects such as red heat, flashback and flame lift can be suppressed.

  Further, as in the present embodiment, the # 1 vent holes 69a and the # 2 vent holes 69a are alternately arranged, and the gas introduction at the central position O2 of the vent hole 69a is performed by each gas burner 6 and the gas burner 6 adjacent thereto. If the positional relationship of the port 65a with respect to the center position O1 is varied, the frequency of the combustion vibration generated at each position in the front-rear direction of each gas burner 6 and the frequency of the combustion vibration generated at the same position in the front-rear direction of the gas burner 6 adjacent thereto. Make a difference. Therefore, the mutual interference action due to the frequency difference can be obtained efficiently, and the combustion noise can be reduced more effectively. Note that a vent hole whose center position is substantially matched with the center position of the gas introduction port 65a may be disposed between the vent hole 69a of # 1 and the vent hole 69a of # 2.

  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 embodiment, all the vent holes 69a of the damper 69 have the same size. However, when the distribution of the primary air to the gas burner 6 is uneven due to the influence of the position of the duct 5a of the combustion fan 5 or the like. The sizes of the air holes 69a may be varied so that the primary air amounts of all the gas burners 6 are equal. Moreover, although the gas burner 6 of the said embodiment is a concentration combustion type burner provided with the burner cap 62, this invention is applicable similarly to the gas burner which does not have a burner cap and is not a concentration combustion type.

  6 ... Gas burner, 63 ... Flame port, 65 ... Mixing tube, 65a ... Gas inlet, 69 ... Damper, 69a ... Vent, O1 ... Center position of gas inlet, O2 ... Center position of vent.

Claims (2)

A combustion apparatus in which a plurality of identical gas burners longitudinally extending in the front-rear direction and having a flame opening at the upper end are arranged side by side, and includes a damper that covers the gas inlet at the upstream end of the mixing tube portion of each gas burner, In addition, in which a vent hole for limiting the primary air that is smaller than the gas inlet that overlaps the gas inlet is formed,
A combustion apparatus characterized in that a positional relationship of a central position of a vent hole with respect to a central position of a gas inlet is made different in some gas burners from other gas burners.   2. A combustion apparatus according to claim 1, wherein the positional relationship between the center position of the vent hole and the center position of the gas inlet is different between each gas burner and the gas burner adjacent thereto.

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